Patent Publication Number: US-7715108-B2

Title: Image forming optical system and electronic image pickup apparatus using image forming optical system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   The present application is based upon and claims the benefit of priority from the prior Japanese Patent Application Nos. 2005-264635 filed on Sep. 13, 2005, 2005-264643 filed on Sep. 13, 2005, 2006-241564 filed on Sep. 6, 2006, and 2006-241590 filed on Sep. 6, 2006, the entire contents of which are incorporated herein by reference. 
   TECHNICAL FIELD 
   The present invention relates to an image forming optical system which is used in an extremely small image pickup module, and an electronic image pickup apparatus which includes the image forming optical system. 
   BACKGROUND ART 
   In recent years, a digital camera has been widely used as a next generation camera replacing a silver salt 35 mm film camera. Recently, there has been an increasing reduction in a size, and thinning of a digital camera. Moreover, a camera function (hereinafter called as an ‘image pickup module’) has been mounted even in a portable telephone, the use of which has also been increasing widely. For mounting this image pickup module in the portable telephone, an optical system has to be smaller and thinner than an optical system of the digital camera. Particularly, in a zoom lens, the reduction in size and the thinning have been sought. However, a zoom lens having a size reduced to be capable of being mounted in the portable telephone has not been known much. 
   As a typical means for reducing the size and thinning the zoom lens, the following two means can be taken into consideration. In other words, 
   A. To use a collapsible lens barrel, and to accommodate the optical system in a thickness (depth) of a casing. This collapsible lens barrel is a lens barrel having a structure in which, the optical system is protruded from a camera casing at the time of taking a picture, and is accommodated in the camera while carrying. 
   B. To accommodate the optical system in a direction of width or in a direction of height of the casing by adopting a dioptric system. This dioptric system is an optical system having a structure in which, an optical path (optical axis) of the optical system is folded by a reflecting optical element such as a mirror or a prism. 
   However, in a structure in which the abovementioned means A is used, the number of lenses forming the optical system or the number of movable lens groups is still large, and it is difficult to carry out the reduction in the size, and the thinning of the casing. 
   Moreover, in a structure in which the abovementioned means B is used, it is easy to make the casing thin as compared to a case in which the means in the abovementioned A is used, but an amount of movement of the movable lens group at the time of zooming, and the number of lenses forming the optical system tend to increase. Therefore, volumetrically, it is not at all suitable for the reduction in size. 
   DISCLOSURE OF THE INVENTION 
   An image forming optical system according to the present invention is characterized in that, in an image forming optical system having a positive lens group, a negative lens group, and an aperture stop, 
   the negative lens group is disposed at an image side of the aperture stop, 
   the negative lens group has a cemented lens which is formed by cementing a plurality of lenses, and 
   in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be νd, when a straight line indicated by Nd=α×νd+β (where, α=−0.017) is set, 
   Nd and νd of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1a), and a line when an upper limit value is in a range of the following conditional expression (1a), and an area determined by following conditional expressions (2a) and (3a)
 
1.45&lt;β&lt;2.15  (1a)
 
1.30&lt;Nd&lt;2.20  (2a)
 
3&lt;νd&lt;12  (3a)
 
   Here, Nd denotes a refractive index, and νd denotes an Abbe&#39;s number. 
   Moreover, an image forming optical system according to the present invention is characterized in that, in an image forming optical system having a positive lens group, a negative lens group, and an aperture stop, 
   the negative lens group is disposed at the image side of the aperture stop, 
   the negative lens group has a cemented lens which is formed by cementing a plurality of lenses, and 
   in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be νd, when a straight line indicated by Nd=α×νd+β (where, α=−0.017) is set, 
   Nd and νd of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1b), and a line when an upper limit value is in a range of the following conditional expression (1b), and an area determined by following conditional expressions (2b) and (3b)
 
1.45&lt;β&lt;2.15  (1b)
 
1.58&lt;Nd&lt;2.20  (2b)
 
3&lt;νd&lt;40  (3b)
 
   Here, Nd denotes a refractive index, and νd denotes an Abbe&#39;s number. 
   Moreover, an electronic image pickup apparatus of the present invention is characterized in that the electronic image pickup apparatus includes an image forming optical system mentioned in any one above, an electronic image pickup element, and an image processing means which is capable of processing image data obtained by image pickup by the electronic image pickup element, of an image which is formed through the image forming optical system, and outputting image data in which, a shape is changed upon processing, and in which the image forming optical system is a zoom lens, and the zoom lens satisfies a following conditional expression at a time of infinite object point focusing.
 
0.7&lt; y   07 /( fw ·tan ω 07w )&lt;0.96
 
   where, y 07  is indicated as y 07 =0.7 y 10  when, in an effective image pickup surface (surface in which, image pickup is possible), a distance from a center up to a farthest point (maximum image height) is let to be y 10 . Moreover, ω 07w  is an angle with respect to an optical axis in a direction of an object point corresponding to an image point connecting from a center on the image pickup surface in a wide angle end up to a position of y 07 . 
   According to the present invention, it is possible to achieve a thinning and a size reduction of a volume of the image forming optical system, and further to have both of a widening of an angle and a favorable correction of various aberrations in the electronic image pickup apparatus of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a cross-sectional view along an optical axis showing an optical arrangement at the time of an infinite object point focusing at a wide angle end of a zoom lens according to a first embodiment of the present invention; 
       FIG. 2A ,  FIG. 2B , and  FIG. 2C  are diagrams showing a spherical aberration, an astigmatism, a distortion, and a chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the first embodiment, where,  FIG. 2A  shows a state at the wide angle end,  FIG. 2B  shows an intermediate state, and  FIG. 2C  shows a state at a telephoto end; 
       FIG. 3  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a second embodiment of the present invention; 
       FIG. 4A ,  FIG. 4B , and  FIG. 4C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the second embodiment, where,  FIG. 4A  shows the state at the wide angle end,  FIG. 4B  shows the intermediate state, and  FIG. 4C  shows the state at the telephoto end; 
       FIG. 5  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a third embodiment of the present invention; 
       FIG. 6A ,  FIG. 6B , and  FIG. 6C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the third embodiment, where,  FIG. 6A  shows the state at the wide angle end,  FIG. 6B  shows the intermediate state, and  FIG. 6C  shows the state at the telephoto end; 
       FIG. 7  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fourth embodiment of the present invention; 
       FIG. 8A ,  FIG. 8B , and  FIG. 8C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fourth embodiment, where,  FIG. 8A  shows the state at the wide angle end,  FIG. 8B  shows the intermediate state, and  FIG. 8C  shows the state at the telephoto end; 
       FIG. 9  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fifth embodiment of the present invention; 
       FIG. 10A ,  FIG. 10B , and  FIG. 10C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fifth embodiment, where,  FIG. 10A  shows the state at the wide angle end,  FIG. 10B  shows the intermediate state, and  FIG. 10C  shows the state at the telephoto end; 
       FIG. 11  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a sixth embodiment of the present invention; 
       FIG. 12A ,  FIG. 12B , and  FIG. 12C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the sixth embodiment, where,  FIG. 12A  shows the state at the wide angle end,  FIG. 12B , shows the intermediate state, and FIG.  12 C shows the state at the telephoto end; 
       FIG. 13  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a seventh embodiment of the present invention; 
       FIG. 14A ,  FIG. 14B , and  FIG. 14C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the seventh embodiment, where,  FIG. 14A  shows the state at the wide angle end,  FIG. 14B  shows the intermediate state, and  FIG. 14C  shows the state at the telephoto end; 
       FIG. 15  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to an eighth embodiment of the present invention; 
       FIG. 16A ,  FIG. 16B , and  FIG. 16C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the eighth embodiment, where,  FIG. 16A  shows the state at the wide angle end,  FIG. 16B  shows the intermediate state, and  FIG. 16C  shows the state at the telephoto end; 
       FIG. 17  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a ninth embodiment of the present invention; 
       FIG. 18A ,  FIG. 18B , and  FIG. 18C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the ninth embodiment, where,  FIG. 18A  shows the state at the wide angle end,  FIG. 18B  shows the intermediate state, and  FIG. 18C  shows the state at the telephoto end; 
       FIG. 19  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a tenth embodiment of the present invention; 
       FIG. 20A ,  FIG. 20B , and  FIG. 20C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the tenth embodiment, where,  FIG. 20A  shows the state at the wide angle end,  FIG. 20B  shows the intermediate state, and  FIG. 20C  shows the state at the telephoto end; 
       FIG. 21  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to an eleventh embodiment of the present invention; 
       FIG. 22A ,  FIG. 22B , and  FIG. 22C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the eleventh embodiment, where,  FIG. 22A  shows the state at the wide angle end,  FIG. 22B  shows the intermediate state, and  FIG. 22C  shows the state at the telephoto end; 
       FIG. 23  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twelfth embodiment of the present invention; 
       FIG. 24A ,  FIG. 24B , and  FIG. 24C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twelfth embodiment, where,  FIG. 24A  shows the state at the wide angle end,  FIG. 24B  shows the intermediate state, and  FIG. 24C  shows the state at the telephoto end; 
       FIG. 25  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirteenth embodiment of the present invention; 
       FIG. 26A ,  FIG. 26B , and  FIG. 26C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirteenth embodiment, where  FIG. 26A  shows the state at the wide angle end,  FIG. 26B  shows the intermediate state, and  FIG. 26C  shows the state at the telephoto end; 
       FIG. 27  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fourteenth embodiment of the present invention; 
       FIG. 28A ,  FIG. 28B , and  FIG. 28C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fourteenth embodiment, where,  FIG. 28A  shows the state at the wide angle end,  FIG. 28B  shows the intermediate state, and  FIG. 28C  shows the state at the telephoto end; 
       FIG. 29  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fifteenth embodiment of the present invention; 
       FIG. 30A ,  FIG. 30B , and  FIG. 30C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fifteenth embodiment, where,  FIG. 30A  shows the state at the wide angle end,  FIG. 30B  shows the intermediate state, and  FIG. 30C  shows the state at the telephoto end; 
       FIG. 31  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a sixteenth embodiment of the present invention; 
       FIG. 32A ,  FIG. 32B , and  FIG. 32C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the sixteenth embodiment, where,  FIG. 32A  shows the state at the wide angle end,  FIG. 32B  shows the intermediate state, and  FIG. 32C  shows the state at the telephoto end; 
       FIG. 33  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a seventeenth embodiment of the present invention; 
       FIG. 34A ,  FIG. 34B , and  FIG. 34C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the seventeenth embodiment, where,  FIG. 34A  shows the state at the wide angle end,  FIG. 34B  shows the intermediate state, and  FIG. 34C  shows the state at the telephoto end; 
       FIG. 35  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to an eighteenth embodiment of the present invention; 
       FIG. 36A ,  FIG. 36B , and  FIG. 36C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the eighteenth embodiment, where,  FIG. 36A  shows the state at the wide angle end,  FIG. 36B  shows the intermediate state, and  FIG. 36C  shows the state at the telephoto end; 
       FIG. 37  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a nineteenth embodiment of the present invention; 
       FIG. 38A ,  FIG. 38B , and  FIG. 38C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the nineteenth embodiment, where,  FIG. 38A  shows the state at the wide angle end,  FIG. 38B  shows the intermediate state, and  FIG. 38C  shows the state at the telephoto end; 
       FIG. 39  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twentieth embodiment of the present invention; 
       FIG. 40A ,  FIG. 40B , and  FIG. 40C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twentieth embodiment, where,  FIG. 40A  shows the state at the wide angle end,  FIG. 40B  shows the intermediate state, and  FIG. 40C  shows the state at the telephoto end; 
       FIG. 41  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty first embodiment of the present invention; 
       FIG. 42A ,  FIG. 42B , and  FIG. 42C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty first embodiment, where,  FIG. 42A  shows the state at the wide angle end,  FIG. 42B  shows the intermediate state, and  FIG. 42C  shows the state at the telephoto end; 
       FIG. 43  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty second embodiment of the present invention; 
       FIG. 44A ,  FIG. 44B , and  FIG. 44C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty second embodiment, where,  FIG. 44A  shows the state at the wide angle end,  FIG. 44B  shows the intermediate state, and  FIG. 44C  shows the state at the telephoto end; 
       FIG. 45  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty third embodiment of the present invention; 
       FIG. 46A ,  FIG. 46B , and  FIG. 46C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty third embodiment, where,  FIG. 46A  shows the state at the wide angle end,  FIG. 46B  shows the intermediate state, and  FIG. 46C  shows the state at the telephoto end; 
       FIG. 47  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty fourth embodiment of the present invention; 
       FIG. 48A ,  FIG. 48B , and  FIG. 48C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty fourth embodiment, where,  FIG. 48A  shows the state at the wide angle end,  FIG. 48B  shows the intermediate state, and  FIG. 48C  shows the state at the telephoto end; 
       FIG. 49  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty fifth embodiment of the present invention; 
       FIG. 50A ,  FIG. 50B , and  FIG. 50C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty fifth embodiment, where,  FIG. 50A  shows the state at the wide angle end,  FIG. 50B  shows the intermediate state, and  FIG. 50C  shows the state at the telephoto end; 
       FIG. 51  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty sixth embodiment of the present invention; 
       FIG. 52A ,  FIG. 52B , and  FIG. 52C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty sixth embodiment, where,  FIG. 52A  shows the state at the wide angle end,  FIG. 52B  shows the intermediate state, and  FIG. 52C  shows the state at the telephoto end; 
       FIG. 53  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty seventh embodiment of the present invention; 
       FIG. 54A ,  FIG. 54B , and  FIG. 54C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty seventh embodiment, where,  FIG. 54A  shows the state at the wide angle end,  FIG. 54B  shows the intermediate state, and  FIG. 54C  shows the state at the telephoto end; 
       FIG. 55  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty eighth embodiment of the present invention; 
       FIG. 56A ,  FIG. 56B , and  FIG. 56C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty eighth embodiment, where,  FIG. 56A  shows the state at the wide angle end,  FIG. 56B  shows the intermediate state, and  FIG. 56C  shows the state at the telephoto end; 
       FIG. 57  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty ninth embodiment of the present invention; 
       FIG. 58A ,  FIG. 58B , and  FIG. 58C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty ninth embodiment, where,  FIG. 58A  shows the state at the wide angle end,  FIG. 58B  shows the intermediate state, and  FIG. 58C  shows the state at the telephoto end; 
       FIG. 59  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirtieth embodiment of the present invention; 
       FIG. 60A ,  FIG. 60B , and  FIG. 60C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirtieth embodiment, where,  FIG. 60A  shows the state at the wide angle end,  FIG. 60B  shows the intermediate state, and  FIG. 60C  shows the state at the telephoto end; 
       FIG. 61  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty first embodiment of the present invention; 
       FIG. 62A ,  FIG. 62B , and  FIG. 62C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty first embodiment, where,  FIG. 62A  shows the state at the wide angle end,  FIG. 62B  shows the intermediate state, and  FIG. 62C  shows the state at the telephoto end; 
       FIG. 63  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty second embodiment of the present invention; 
       FIG. 64A ,  FIG. 64B , and  FIG. 64C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty second embodiment, where,  FIG. 64A  shows the state at the wide angle end,  FIG. 64B  shows the intermediate state, and  FIG. 64C  shows the state at the telephoto end; 
       FIG. 65  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty third embodiment of the present invention; 
       FIG. 66A ,  FIG. 66B , and  FIG. 66C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty third embodiment, where,  FIG. 66A  shows the state at the wide angle end,  FIG. 66B  shows the intermediate state, and  FIG. 66C  shows the state at the telephoto end; 
       FIG. 67  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty fourth embodiment of the present invention; 
       FIG. 68A ,  FIG. 68B , and  FIG. 68C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty fourth embodiment, where,  FIG. 68A  shows the state at the wide angle end,  FIG. 68B  shows the intermediate state, and  FIG. 68C  shows the state at the telephoto end; 
       FIG. 69  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty fifth embodiment of the present invention; 
       FIG. 70A ,  FIG. 70B , and  FIG. 70C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty fifth embodiment, where,  FIG. 70A  shows the state at the wide angle end,  FIG. 70B  shows the intermediate state, and  FIG. 70C  shows the state at the telephoto end; 
       FIG. 71  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty sixth embodiment of the present invention; 
       FIG. 72A ,  FIG. 72B , and  FIG. 72C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty sixth embodiment, where,  FIG. 72A  shows the state at the wide angle end,  FIG. 72B  shows the intermediate state, and  FIG. 72C  shows the state at the telephoto end; 
       FIG. 73  is a cross-sectional view along the optical axis showing an optical arrangement at the wide angle end of a zoom lens according to a thirty seventh embodiment of the present invention; 
       FIG. 74A ,  FIG. 74B , and  FIG. 74C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty seventh embodiment, where,  FIG. 74A  shows the state at the wide angle end,  FIG. 74B  shows the intermediate state, and  FIG. 74C  shows the state at the telephoto end; 
       FIG. 75  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty eighth embodiment of the present invention; 
       FIG. 76A ,  FIG. 76B , and  FIG. 76C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty eighth embodiment, where,  FIG. 76A  shows the state at the wide angle end,  FIG. 76B  shows the intermediate state, and  FIG. 76C  shows the state at the telephoto end; 
       FIG. 77  is a frontward perspective view showing an appearance of a digital camera  40  in which, a zoom optical system according to the present invention is incorporated; 
       FIG. 78  is a rearward perspective view of the digital camera  40 ; 
       FIG. 79  is a cross-sectional view showing an optical arrangement of the digital camera  40 ; 
       FIG. 80  is a frontward perspective view of a personal computer  300  with its cover opened, which is an example of an information processing apparatus in which, the zoom optical system of the present invention is built-in as an objective optical system; 
       FIG. 81  is a cross-sectional view of a photographic optical system  303  of the personal computer  300 ; 
       FIG. 82  is a side view of the personal computer  300 ; and 
       FIG. 83A ,  FIG. 83B , and  FIG. 83C  are diagrams showing a portable telephone which is an example of the information processing apparatus in which, the zoom optical system of the present invention is built-in as the taking optical system, where,  FIG. 83A  is a front view of a portable telephone  400 ,  FIG. 83B  is a side view of the portable telephone  400 , and  FIG. 83C  is a cross-sectional view of a taking optical system  405 . 
   

   BEST MODE FOR CARRYING OUT THE INVENTION 
   Prior to description of embodiments, an action and an effect of the present invention will be described below. 
   An image forming optical system of the present invention, where the image forming optical system includes a positive lens group, a negative lens group, and an aperture stop, has a basic structure in which the negative lens group is disposed at an image side of the aperture stop, and the negative lens group includes a cemented lens which is formed by cementing a plurality of lenses. 
   In this manner, in the basic structure, since the cemented lens is used in the negative lens group which is at the image side of the aperture stop, a change in a longitudinal chromatic aberration in a zoom lens, at the time zooming, is easily suppressed. Moreover, with a fewer number of lenses, it is possible to suppress sufficiently an occurrence of color spreading over a zoom range. Moreover, although an existence of the negative lens group at the image side of the aperture stop brings about a substantial effect in shortening the entire length, the thickness militates against shortening the entire length when the optical system is collapsed. However, in this basic structure, since the cemented lens can be formed to be thin, it is possible to make thin the negative lens group at the image side of the aperture stop. As a result, it is possible to realize an optical system which is thin and has a short length. 
   Further, in the abovementioned basic structure, it is preferable that at least one lens forming the cemented lens has the following characteristics. In other words, in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be νd, when a straight line indicated by Nd=α×νd+β (where, α=−0.017) is set, it is desirable that Nd and νd of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1a), and a line when an upper limit value is in a range of the following conditional expression (1a), and an area determined by following conditional expressions (2a) and (3a).
 
1.45&lt;β&lt;2.15  (1a)
 
1.30&lt;Nd&lt;2.20  (2a)
 
3&lt;νd&lt;12  (3a)
 
   Here, Nd denotes a refractive index, and νd denotes an Abbe&#39;s number. 
   Here, a glass means a lens material such as a glass and a resin. Moreover, as a cemented lens, a lens in which a plurality of lenses made of a glass selected appropriately is cemented, is used. 
   When a value is lower than the lower limit value in the conditional expression (1a), since a refractive index is low, an effect when an aspheric surface is provided on a side which is in contact with air is small, and a correction of a spherical aberration, a coma aberration, and a distortion becomes difficult. Or, since the Abbe&#39;s number is low, a correction of a chromatic aberration, as an extremely thin cemented lens is possible, but when the side in contact with air is made to be an aspheric surface, a chromatic coma and a chromatic aberration of magnification of high order are susceptible to occur, and a degree of freedom of an aberration correction is decreased. 
   When a value is higher than an upper limit value in the conditional expression (1a), since a power and a thickness of the cemented lens is required to be more than a certain magnitude for the correction of the chromatic aberration, it becomes susceptible to be effected by optical characteristics which depend on an environment of the material. 
   When a value is lower than a lower limit value in the conditional expression (2a), the effect when the aspheric surface is provided on the side which is in contact with air is small, and the correction of the spherical aberration, the coma aberration, and the distortion becomes difficult. 
   When a value is higher than an upper limit value in the conditional expression (2a), in a case of a material which includes organic properties, when the refractive index is excessively high, a temperature variance becomes excessively high, and optical characteristics which depend on the environment are susceptible to become unstable. Moreover, a reflectivity becomes excessively high, and a ghost is susceptible to occur even when coating is optimized. 
   When a value is lower than a lower limit value in the conditional expression (3a), the correction of the chromatic aberration, as an extremely thin cemented lens is possible, but when the side in contact with air is made to be an aspheric surface, the chromatic coma and the chromatic aberration of magnification of high order are susceptible to occur, and the degree of freedom of the aberration correction is decreased. 
   When a value is higher than an upper limit value in the conditional expression (3a), it is necessary to enhance a refracting power of the cemented lens for correcting the chromatic aberration, and it is advantageous for a correction of a Petzval&#39;s sum, but it becomes susceptible to be effected by the optical characteristics which depend on the environment of the material. 
   It is more preferable when a following conditional expression (1a′) is satisfied.
 
1.48&lt;β&lt;2.04  (1a′)
 
   Furthermore, it is even more preferable when a following conditional expression (1a″) is satisfied.
 
1.50&lt;β&lt;2.00  (1a″)
 
   Moreover, it is more preferable when a following conditional expression (2a′) is satisfied.
 
1.58&lt;Nd&lt;2.10  (2a′)
 
   Furthermore, it is even more preferable when a following conditional expression (2a″) is satisfied.
 
1.63&lt;Nd&lt;1.95  (2a″)
 
   Moreover, it is more preferable when a following conditional expression (3a′) is satisfied.
 
5&lt;νd&lt;10  (3a′)
 
   Furthermore, it is even more preferable when a following conditional expression (3a″) is satisfied.
 
6&lt;νd&lt;9  (3a″)
 
   Or, in the abovementioned basic structure, it is preferable that at least one lens forming the cemented lens has the following characteristics. In other words, in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be νd, when a straight line indicated by Nd=α×νd+β (where, α=−0.017) is set, Nd and νd of at least one lens forming the cemented lens is included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1b), and a line when an upper limit value is in a range of the following conditional expression (1b), and an area determined by following conditional expressions (2b) and (3b).
 
1.45&lt;β&lt;2.15  (1b)
 
1.58&lt;Nd&lt;2.20  (2b)
 
3&lt;νd&lt;40  (3b)
 
   Here, Nd denotes the refractive index, and νd denotes the Abbe&#39;s number. 
   When a value is lower than a lower limit value in the conditional expression (1b), since the refractive index is low, the effect when the aspheric surface is provided on the side which is in contact with air is small, and the correction of the spherical aberration, the coma aberration, and the distortion becomes difficult. Or, since the Abbe&#39;s number is low, the correction of the chromatic aberration, as an extremely thin cemented lens is possible, but when the side in contact with air is made to be an aspheric surface, the chromatic coma, and the chromatic aberration of magnification of high order are susceptible to occur, and the degree of freedom of the aberration correction is decreased. 
   When a value is higher than an upper limit value in the conditional expression (1b), a correction level of the chromatic aberration and the Petzval&#39;s sum become same as of a general optical glass lens, and characteristics of the present invention are not achieved. 
   When a value is lower than a lower limit value in the conditional expression (2b), the effect when the aspheric surface is provided on the side which is in contact with air is small, and the correction of the spherical aberration, the coma aberration, and the distortion becomes difficult. 
   When a value is higher than an upper limit value in the conditional expression (2b), in the case of a material which includes organic properties, when the refractive index is excessively high, the temperature variance becomes excessively high, and the optical characteristics which depend on the environment are susceptible to become unstable. Moreover, the reflectivity becomes excessively high, and a ghost is susceptible to occur even when the coating is optimized. 
   When a value is lower than a lower limit value in the conditional expression (3b), the correction of the chromatic aberration, as an extremely thin cemented lens is possible, but when the side in contact with air is made to be an aspheric surface, the chromatic coma and the chromatic aberration of magnification of high order are susceptible to occur, and the degree of freedom of the aberration correction is decreased. 
   When a value is higher than an upper limit value in the conditional expression (3b), it is necessary to enhance the refracting power of the cemented lens for correcting the chromatic aberration, and it is advantageous for the correction of the Petzval&#39;s sum, but it becomes susceptible to be effected by the optical characteristics which depend on the environment of the material. 
   It is more preferable when a following conditional expression (1b′) is satisfied.
 
1.48&lt;β&lt;2.04  (1b′)
 
   Furthermore, it is even more preferable when a following conditional expression (1b″) is satisfied.
 
1.50&lt;β&lt;2.00  (1b″)
 
   Moreover, it is more preferable when a following conditional expression (2b′) is satisfied.
 
1.60&lt;Nd&lt;2.10  (2b′)
 
   Furthermore, it is even more preferable when a following conditional expression (2b″) is satisfied.
 
1.63&lt;Nd&lt;1.95  (2b″)
 
   Moreover, it is more preferable when a following conditional expression (3b′) is satisfied.
 
5&lt;νd&lt;30  (3b′)
 
   Furthermore, it is even more preferable when a following conditional expression (3b″) is satisfied.
 
6&lt;νd&lt;25  (3b″)
 
   Moreover, it is preferable that the cemented lens is formed by a lens (hereinafter, called as a ‘predetermined lens’) having the values of Nd and νd which are included in both the areas mentioned above, and a lens other than the predetermined lens, and a center thickness along an optical axis of the predetermined lens is less than a center thickness along an optical axis of the other lens. By making such an arrangement, it is possible to realize a more favorable correction of each aberration mentioned above, and thinning of the lens group. 
   Moreover, the cemented lens may be a compound lens which is formed by closely adhering and hardening a resin on a lens surface (lens surface of the other lens), in order to improve a manufacturing accuracy. Here, the resin which is adhered closely and hardened corresponds to the predetermined lens. 
   Moreover, the cemented lens may be a compound lens which is formed by closely adhering and hardening a glass on the lens surface (lens surface of the other lens), as it is advantageous for resistance such as a light resistance and a chemical resistance. Here, the glass which is adhered closely and hardened corresponds to the predetermined lens. 
   Moreover, in the cemented lens, a center thickness t 1  along the optical axis of the predetermined lens (one lens in which Nd and νd are included in both the areas mentioned above) may satisfy a following conditional expression (4), in order to make a size small and to carry out molding stably.
 
0.22&lt;t1&lt;2.0  (4)
 
   It is more preferable that a following conditional expression (4′) is satisfied.
 
0.3&lt;t1&lt;1.5  (4′)
 
   Furthermore, it is even more preferable that a following conditional expression (4″) is satisfied.
 
0.32&lt;t1&lt;1.0  (4″)
 
   Moreover, the image forming optical system may be a zoom lens of which, a group on the closest side of an object is a positive lens group, from a viewpoint of having a high magnification of the zoom and an improvement in a brightness of the lens. 
   Moreover, the image forming optical system may be a zoom lens of which, a group on the closest side of an object is a negative lens group, for making the size small. 
   Moreover, the image forming optical system may have a prism for folding, for facilitating size reduction of an optical system with respect to a direction of taking a photo. 
   Moreover, in the image forming optical system, the prism may be in a group on the closest side of an object, for further facilitating thinning. 
   Incidentally, when a pixel size of the electronic image pickup element becomes smaller than a certain size, a component of a frequency higher than a Nyquist frequency is eliminated due to an effect of diffraction. Therefore, when this is used, it is possible to omit an optical low-pass filter. This is preferable from a point of making the entire optical system as thin as possible. 
   For this, it is preferable that a following conditional expression (6) is satisfied.
 
 Fw≧a (μm)  (6)
 
   where, Fw is a full-aperture F value, and a is a distance between pixels (unit: μm) in a horizontal direction of the electronic image pickup element. 
   When the conditional expression (6) is satisfied, the optical low-pass filter is not required to be disposed in an optical path. Accordingly, it is possible to make the optical system small. 
   In a case of satisfying the conditional expression (6), it is preferable that the aperture stop is let to be open only. This means that the optical system in this case is an optical system with a constant diameter of the aperture stop all the time. Moreover, in the optical system in this case, since an operation of narrowing is not necessary, it is possible to omit a narrowing mechanism. Accordingly, the size can be made small saving that much space. When the conditional expression (6) is not satisfied, the optical low-pass filter is necessary. 
   Moreover, it is more preferable that a conditional expression (6′) is satisfied.
 
 Fw≧ 1.2 a (μm)  (6′)
 
   Furthermore, it is even more preferable that a conditional expression (6″) is satisfied.
 
Fw≧1.4 a (μm)  (6″)
 
   Finally, an electronic image pickup apparatus will be described below. As the electronic image pickup apparatus, an electronic image pickup apparatus in which, both a thinning of depth and a widening of image angle are realized is preferable. 
   Here, it is assumed that an infinite object is imaged by an optical system which has no distortion. In this case, since the image which is formed has no distortion,
 
 f=y /tan ω
 
holds.
 
   Here, y is a height of an image point from an optical axis, f is a focal length of the image forming system, and ω is an angle with respect to an optical axis in a direction of an object point corresponding to the image point connecting from a center on an image pickup surface, up to a position of y. 
   On the other hand, when the optical system has a barrel distortion,
 
 f&gt;y /tan ω
 
holds. In other words, when f and y are let to be constant values, ω becomes a substantial value.
 
   Therefore, in the electronic image pickup apparatus, it is preferable to use a zoom lens as the image forming optical system. As a zoom lens, particularly in a focal length near a wide angle end, an optical system having a substantial barrel distortion may be used intentionally. In this case, since a purpose is served without correcting the distortion, it is possible to achieve the widening of the image angle of the optical system. However, an image of the object is formed on the electronic image pickup element, in a state of having the barrel distortion. Therefore, in the electronic image pickup apparatus, image data obtained by the electronic image pickup element is processed by an image processing. In this process, the image data (a shape of the image data) is changed such that the barrel distortion is corrected. By changing the image data, image data which is obtained finally, takes a shape almost similar to the object. Accordingly, based on this image data, the image of the object may be output to a CRT or a printer. 
   Here, as the image forming optical system (zoom lens), an image forming optical system which satisfies a following conditional expression (7) at the time of the infinite object point focusing may be adopted.
 
0.7&lt; y   07 /( fw ·tan ω 07w )&lt;0.96  (7)
 
   where, y 07  is indicated as y 07 =0.7y 10  when, in an effective image pickup surface (surface in which image pickup is possible), a distance from a center up to a farthest point (maximum image height) is let to be y 10 . Moreover, ω 07w  is an angle with respect to an optical axis in a direction of an object point corresponding to an image point connecting from a center on the image pickup surface at a wide angle end, up to a position of y 07 . 
   The conditional expression (7) mentioned above is an expression in which, a degree of the barrel distortion in a zoom wide angle end is regulated. When the conditional expression (7) is satisfied, it is possible to fetch information of the wide image angle without making the optical system enlarged. An image which is distorted to barrel shape is subjected to photoelectric conversion, and becomes image data which is distorted to barrel shape. However, on the image data which is distorted to the barrel shape, a process equivalent to a shape change of the image is carried out electrically by the image processing means which is a signal processing system of the electronic image pickup apparatus. When this process is carried out, even when the image data output from the image processing means is reproduced finally by a display apparatus, the distortion is corrected, and an image, almost similar to a shape of an object to be photographed, is achieved. 
   Here, when a value is higher than an upper limit value in the conditional expression (7), particularly, when a value close to 1 is to be taken, it is possible to carry out by the image processing means, a correction equivalent to a correction in which, the distortion is corrected favorably optically, but it is difficult to fetch an image over a wide angle of visibility. On the other hand, when a value is lower than a lower limit value in the conditional expression (7), a rate of enlarging in a direction of radiating in a portion around an image angle when the image distortion due to the distortion of the optical system is corrected by the image processing means, becomes excessively high. As a result of this, deterioration in a sharpness of the area around the image becomes remarkable. 
   On the other hand, by satisfying the conditional expression (7), it is possible to widen the angle (make an angle in a vertical direction in the distortion to be 38° or more), and to make small the optical system. 
   Moreover, it is more preferable when a following conditional expression (7′) is satisfied.
 
0.75 &lt;y   07 /( fw ·tan ω 07w )&lt;0.94  (7′)
 
   Furthermore, it is even more preferable when a following conditional expression (7″) is satisfied.
 
0.80&lt; y   07 /( fw ·tan ω 07w )&lt;0.92  (7″)
 
   The image forming optical system of the present invention, even when an electronic image pickup element of a large number of pixels is used, is capable of achieving thinning and reduction in size of a volume of the image forming optical system, by satisfying or providing each of conditional expressional and structural characteristics mentioned above, and realizing a favorable correction of aberration. Moreover, the image forming optical system of the present invention is capable of providing (satisfying) in combination the conditional expressional and structural characteristics mentioned above. In this case, it is possible to achieve further reduction in size and thinning, or the favorable aberration correction. Moreover, in the electronic image pickup apparatus having the image forming optical system of the present invention, it is possible to achieve the thinning and reduction in size of the volume of the image forming optical system, and further, to have both the favorable correction of various aberrations, and widening of the angle. 
   Embodiments of the present invention will be described below by using the accompanying diagrams. 
   As a zoom lens of the present invention, a five-group structure or a four-group structure can be taken into consideration. In a zoom lens of the five-group structure, it is preferable to dispose from an object side, each lens group in order of a first lens group having a positive refracting power, a second lens group having a negative refracting power, a third lens group having a positive refracting power, a fourth lens group having a negative refracting power, and a fifth lens group having a positive refracting power. 
   Here, it is preferable that the first lens group includes a negative lens, a prism, and a positive lens. At this time, it is more preferable to dispose these in order of the negative lens, the prism, and the positive lens, from the object side. Moreover, the first lens group may include only one negative lens, one prism, and one positive lens. 
   Moreover, it is preferable that the second lens group includes a positive lens and a negative lens. At this time, it is more preferable to dispose these in order of the negative lens and the positive lens, from the object side. Moreover, the second lens group may include only one positive lens and one negative lens. 
   Moreover, it is preferable that the third lens group includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens by the positive lens and the negative lens, and to dispose the cemented lens such that the positive lens is positioned at the object side. The third lens group may be formed by only one cemented lens. In this case, the cemented lens is formed by one positive lens and one negative lens. 
   Moreover, it is preferable that the fourth lens group includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens by the positive lens and the negative lens, and to dispose the cemented lens such that the negative lens is positioned at the object side. Or, it is even more preferable to form the cemented lens by the negative lenses and to dispose the cemented lens such that the negative lens having a thick center-thickness is positioned at the object side. Moreover, the fourth lens group may be formed by only one cemented lens. In this case, the cemented lens is formed by two negative lenses, or by one positive lens and one negative lens. 
   Moreover, it is preferable that the fifth lens group includes a positive lens. At this time, it is preferable to form the fifth lens group by only one positive lens. 
   Moreover, in a zoom lens of the four-group structure, it is preferable to dispose each lens group in order of a first lens group having a negative refracting power, a second lens group having a positive refracting power, a third lens group having a negative refracting power, and a fourth lens group having a positive refracting power, from the object side. 
   Here, it is preferable that the first lens group includes a negative lens, a prism, and a cemented lens. At this time, it is more preferable to dispose these in order of the negative lens, the prism, and the cemented lens, from the object side. Moreover, it is preferable to form the cemented lens by a positive lens and a negative lens, and to dispose the cemented lens such that the positive lens is positioned at the object side. The first lens group may include only one negative lens, one prism, and one cemented lens. In this case, the cemented lens is formed by one positive lens and one negative lens. 
   Moreover, it is preferable that the second lens group includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens by the positive lens and the negative lens, and to dispose the cemented lens such that the positive lens is positioned at the object side. The second lens group may be formed by only one cemented lens. In this case, the cemented lens is formed by one positive lens and one negative lens. 
   Moreover, it is preferable that the third lens group includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens by the positive lens and the negative lens, and to dispose the cemented lens such that the negative lens is positioned at the object side. The third lens group may include only one cemented lens. In this case, the cemented lens is formed by one positive lens and one negative lens. 
   Moreover, it is preferable that the fourth lens group includes a positive lens and a negative lens. At this time, it is preferable to form a cemented lens by the positive lens and the negative lens, and to dispose the cemented lens such that the positive lens is positioned at the object side. The fourth lens group may include only one cemented lens. In this case, the cemented lens is formed by one positive lens and one negative lens. 
   It is possible to distribute a refracting power of one lens into two lenses. Accordingly, in each of the lens groups mentioned above, it is possible to substitute one lens by tow lenses. However, from a point of view of the reduction in size and thinning, it is preferable to let the number of lenses to be substituted by two lenses in each lens group, to be only one. 
   First Embodiment 
     FIG. 1  is a cross-sectional view along an optical axis showing an optical arrangement at the time of an infinite object point focusing at a wide angle end of a zoom lens according to a first embodiment; 
     FIG. 2A ,  FIG. 2B , and  FIG. 2C  are diagrams showing a spherical aberration, an astigmatism, a distortion, and a chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the first embodiment, where,  FIG. 2A  shows a state at the wide angle end,  FIG. 2B  shows an intermediate state, and  FIG. 2C  shows a state at a telephoto end. 
   The zoom lens of the first embodiment, as shown in  FIG. 1 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a biconvex lens L 151 , and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the biconvex lens L 151  in the fifth lens group G 5 . 
   Next, numerical data of optical members forming the zoom lens of the first embodiment will be enumerated. 
   In the numerical data of the first embodiment, r 1 , r 2 , . . . denote a radius of curvature of each lens surface; d 1 , d 2 , . . . denote a thickness or an air space of each lens; νd 1 , νd 2 , . . . denote the Abbe&#39;s number for each lens; Fno. denotes F number; f denotes a focal length of an overall system; and D 0  denotes a distance from the object to the first surface. 
   An aspheric surface shape is expressed by a following expression when a direction of an optical axis is let to be z, a direction orthogonal to the optical axis is let to be y, a conical coefficient is let to be K, and an aspheric coefficient is let to be A4, A6, A8, and A10.
 
 z =( y   2   /r )/[1+{1−(1 +K )( y/r ) 2 } 1/2   ]+A 4 y   4   +A 6 y   6   +A 8 y   8   +A 10 y   10  
 
   Moreover, E denotes a power of 10. These symbols of data values are common even in numerical data of embodiments which will be described later. The conical coefficient might also be denoted by k. 
   Next, numerical data of the first embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 1 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 26.557 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 10.004 
               d2 = 2.9 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 27.042 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −26.824 
               d6 = D6 
             
             
               r7 = −115.521 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.039 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 8.219 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 61.534 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 8.050 
               d12 = 5.71 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.948 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 32.240 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 21.8 
               d15 = 0.6 
               Nd15 = 1.51823 
               νd15 = 58.9 
             
             
               r16 = 10.948 
               d16 = 0.1 
               Nd16 = 1.41244 
               νd16 = 12.42 
             
             
               r17 = 11.980 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 14.280 
               d18 = 1.8 
               Nd18 = 1.741 
               νd18 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r19 = −55.898 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −1.73171E−06 
             
             
                 
               A6 = 2.30891E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.80133E−04 
             
             
                 
               A6 = 1.91619E−05 
             
             
                 
               A8 = −4.14130E−07 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −8.12458E−04 
             
             
                 
               A6 = 2.38978E−05 
             
             
                 
               A8 = −1.03173E−06 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.35152E−04 
             
             
                 
               A6 = 1.51360E−06 
             
             
                 
               A8 = 5.39228E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.21280E−04 
             
             
                 
               A6 = 5.76577E−06 
             
             
                 
               A8 = 7.71463E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.49229E−04 
             
             
                 
               A6 = −4.05344E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 3.47673E−05 
             
             
                 
               A6 = 4.88008E−06 
             
             
                 
               A8 = −1.88759E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.017 
               13.716 
               18.012 
             
             
               FNO. 
               2.85 
               4.82 
               5.88 
             
             
               D6 
               0.8 
               6.96 
               8.38 
             
             
               D10 
               8.97 
               2.81 
               1.38 
             
             
               D11 
               11.35 
               3.74 
               1.19 
             
             
               D14 
               1.7 
               11.95 
               14.21 
             
             
               D17 
               1.46 
               2.01 
               3.34 
             
             
               D19 
               4.73 
               1.56 
               0.51 
             
             
               D23 
               1.38 
               1.37 
               1.37 
             
             
                 
             
          
         
       
     
   
   Second Embodiment 
     FIG. 3  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a second embodiment of the present invention. 
     FIG. 4A ,  FIG. 4B , and  FIG. 4C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the second embodiment, where,  FIG. 4A  shows the state at the wide angle end,  FIG. 4B  shows the intermediate state, and  FIG. 4C  shows the state at the telephoto end. 
   The zoom lens of the second embodiment, as shown in  FIG. 2 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a positive meniscus lens L 151  having a convex surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the positive meniscus lens L 151  having the convex surface directed toward the object side in the fifth lens group G 5 . 
   Next, numerical data of the second embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 2 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 26.496 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 9.996 
               d2 = 2.9 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 27.168 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −21.702 
               d6 = D6 
             
             
               r7 = −53.995 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 5.765 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 7.628 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 54.099 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 8.731 
               d12 = 5.87 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −9.889 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 46.648 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 12.37 
               d15 = 0.6 
               Nd15 = 1.51742 
               νd15 = 52.43 
             
             
               r16 = 12.066 
               d16 = 0.1 
               Nd16 = 1.42001 
               νd16 = 6.55 
             
             
               r17 = 13.273 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 14.366 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = 91.286 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −1.77524E−05 
             
             
                 
               A6 = 1.35220E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −5.85040E−05 
             
             
                 
               A6 = 2.41198E−06 
             
             
                 
               A8 = −9.95533E−08 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.62415E−04 
             
             
                 
               A6 = 5.03585E−06 
             
             
                 
               A8 = −8.34140E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.64134E−04 
             
             
                 
               A6 = 1.47621E−06 
             
             
                 
               A8 = 4.58611E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 5.87773E−04 
             
             
                 
               A6 = 6.51647E−06 
             
             
                 
               A8 = 3.75134E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 8.08669E−05 
             
             
                 
               A6 = −8.28890E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −1.76571E−05 
             
             
                 
               A6 = 6.15880E−06 
             
             
                 
               A8 = −1.80534E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               5.998 
               13.7 
               18.004 
             
             
               FNO. 
               2.85 
               4.82 
               5.88 
             
             
               D6 
               0.8 
               6.92 
               8.4 
             
             
               D10 
               9.01 
               2.88 
               1.4 
             
             
               D11 
               11.01 
               3.53 
               1.2 
             
             
               D14 
               1.7 
               11.37 
               14.09 
             
             
               D17 
               1.55 
               1.9 
               3.15 
             
             
               D19 
               4.67 
               2.14 
               0.5 
             
             
               D23 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Third Embodiment 
     FIG. 5  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a third embodiment of the present invention. 
     FIG. 6A ,  FIG. 6B , and  FIG. 6C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the third embodiment, where,  FIG. 6A  shows the state at the wide angle end,  FIG. 6B  shows the intermediate state, and  FIG. 6C  shows the state at the telephoto end. 
   The zoom lens of the third embodiment, as shown in  FIG. 5 , has in order from the object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a biconvex lens L 151 , and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the biconvex lens L 151  in the fifth lens group G 5 . 
   Next, numerical data of the third embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 3 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 26.257 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 9.999 
               d2 = 2.9 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 25.860 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −26.388 
               d6 = D6 
             
             
               r7 = −83.928 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 5.755 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 7.952 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 69.069 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 8.100 
               d12 = 5.79 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.015 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 35.292 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 15.547 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 11.094 
               d16 = 0.1 
               Nd16 = 1.51824 
               νd16 = 12.85 
             
             
               r17 = 12.203 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 15.707 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = −252.829 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −5.58096E−06 
             
             
                 
               A6 = 2.34663E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.52333E−04 
             
             
                 
               A6 = 1.77314E−05 
             
             
                 
               A8 = −4.21441E−07 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −8.52536E−04 
             
             
                 
               A6 = 2.24073E−05 
             
             
                 
               A8 = −1.28129E−06 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.40161E−04 
             
             
                 
               A6 = 1.66875E−06 
             
             
                 
               A8 = 5.27383E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.04358E−04 
             
             
                 
               A6 = 6.81308E−06 
             
             
                 
               A8 = 7.23678E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 4.50939E−05 
             
             
                 
               A6 = −2.09216E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.89463E−05 
             
             
                 
               A6 = 7.59603E−06 
             
             
                 
               A8 = −2.57963E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               5.999 
               13.701 
               18.003 
             
             
               FNO. 
               2.85 
               4.82 
               5.88 
             
             
               D6 
               0.8 
               6.84 
               8.39 
             
             
               D10 
               8.99 
               2.95 
               1.4 
             
             
               D11 
               11.3 
               3.66 
               1.2 
             
             
               D14 
               1.7 
               11.9 
               14.12 
             
             
               D17 
               1.37 
               1.9 
               3.24 
             
             
               D19 
               4.7 
               1.61 
               0.5 
             
             
               D23 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Fourth Embodiment 
     FIG. 7  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fourth embodiment of the present invention. 
     FIG. 8A ,  FIG. 8B , and  FIG. 8C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fourth embodiment, where,  FIG. 8A  shows the state at the wide angle end,  FIG. 8B  shows the intermediate state, and  FIG. 8C  shows the state at the telephoto end. 
   The zoom lens of the fourth embodiment, as shown in  FIG. 7 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a biconvex lens L 151 , and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the biconvex lens L 151  in the fifth lens group G 5 . 
   Next, numerical data of the fourth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 4 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 26.253 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 10.003 
               d2 = 2.9 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 28.806 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −25.622 
               d6 = D6 
             
             
               r7 = −228.935 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 5.857 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 8.267 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 63.529 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 8.041 
               d12 = 5.85 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −12.545 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 32.953 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 25.26 
               d15 = 0.6 
               Nd15 = 1.54814 
               νd15 = 45.79 
             
             
               r16 = 11.772 
               d16 = 0.1 
               Nd16 = 1.54856 
               νd16 = 7.04 
             
             
               r17 = 12.596 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 15.255 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = −44.718 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.83706E−06 
             
             
                 
               A6 = 3.54530E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −7.86643E−04 
             
             
                 
               A6 = 3.97737E−05 
             
             
                 
               A8 = −6.87077E−07 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −1.35693E−03 
             
             
                 
               A6 = 5.10859E−05 
             
             
                 
               A8 = −1.40625E−06 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.12073E−04 
             
             
                 
               A6 = 1.50035E−06 
             
             
                 
               A8 = 6.45760E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.44758E−04 
             
             
                 
               A6 = −1.99790E−06 
             
             
                 
               A8 = 1.14424E−06 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.91131E−04 
             
             
                 
               A6 = −5.08202E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 9.72262E−05 
             
             
                 
               A6 = 2.70387E−06 
             
             
                 
               A8 = −1.95063E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.003 
               13.694 
               17.997 
             
             
               FNO. 
               2.85 
               4.77 
               5.79 
             
             
               D6 
               0.8 
               6.89 
               8.38 
             
             
               D10 
               8.99 
               2.9 
               1.41 
             
             
               D11 
               11.18 
               3.71 
               1.21 
             
             
               D14 
               1.7 
               11.93 
               14.14 
             
             
               D17 
               1.41 
               1.97 
               3.22 
             
             
               D19 
               4.78 
               1.45 
               0.49 
             
             
               D23 
               1.36 
               1.37 
               1.36 
             
             
                 
             
          
         
       
     
   
   Fifth Embodiment 
     FIG. 9  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fifth embodiment of the present invention. 
     FIG. 10A ,  FIG. 10B , and  FIG. 10C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fifth embodiment, where,  FIG. 10A  shows the state at the wide angle end,  FIG. 10B  shows the intermediate state, and  FIG. 10C  shows the state at the telephoto end. 
   The zoom lens of the fifth embodiment, as shown in  FIG. 9 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a positive meniscus lens L 151  having a convex surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the positive meniscus lens L 151  having the convex surface directed toward the object side in the fifth lens group G 5 . 
   Next, numerical data of the fifth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
           
          
             
               Numerical data 5 
             
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 25.378 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 9.203 
               d2 = 3.71 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 47.204 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −22.238 
               d6 = D6 
             
             
               r7 = −59.956 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.912 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 9.696 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 218.437 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 7.687 
               d12 = 6.26 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −12.317 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 29.010 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 15.343 
               d15 = 0.6 
               Nd15 = 1.58267 
               νd15 = 46.42 
             
             
               r16 = 7.801 
               d16 = 0.1 
               Nd16 = 1.65228 
               νd16 = 12 
             
             
               r17 = 7.969 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 10.663 
               d18 = 1.8 
               Nd18 = 1.7725 
               νd18 = 49.6 
             
             
               (Aspheric surface) 
             
             
               r19 = 182.013 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.56293E−05 
             
             
                 
               A6 = 1.88151E−07 
             
             
                 
               A8 = 0 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.52622E−04 
             
             
                 
               A6 = 1.94506E−05 
             
             
                 
               A8 = −2.27135E−07 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −6.69309E−04 
             
             
                 
               A6 = 1.97817E−05 
             
             
                 
               A8 = −2.00038E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.43312E−05 
             
             
                 
               A6 = 1.49461E−06 
             
             
                 
               A8 = 2.68705E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.23485E−04 
             
             
                 
               A6 = 9.02163E−06 
             
             
                 
               A8 = 9.80727E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.18056E−06 
             
             
                 
               A6 = 2.05787E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.12291E−05 
             
             
                 
               A6 = 9.09050E−06 
             
             
                 
               A8 = −1.55608E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               13.42 
               17.995 
             
             
               FNO. 
               3.37 
               5.23 
               6.58 
             
             
               D6 
               3.92 
               9.22 
               9.7 
             
             
               D10 
               12.74 
               2.46 
               0.47 
             
             
               D11 
               6.15 
               2.51 
               0.43 
             
             
               D14 
               1.57 
               12.09 
               15.5 
             
             
               D17 
               1.33 
               2 
               3.24 
             
             
               D19 
               4.75 
               1.4 
               0.53 
             
             
               D23 
               1.37 
               1.37 
               1.37 
             
             
                 
             
          
         
       
     
   
   Sixth Embodiment 
     FIG. 11  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a sixth embodiment of the present invention. 
     FIG. 12A ,  FIG. 12B , and  FIG. 12C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the sixth embodiment, where,  FIG. 12A  shows the state at the wide angle end,  FIG. 12B  shows the intermediate state, and  FIG. 12C  shows the state at the telephoto end. 
   The zoom lens of the sixth embodiment, as shown in  FIG. 11 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which his formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a negative meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The negative meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a positive meniscus lens L 151  having a convex surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the negative meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the positive meniscus lens L 151  having the convex surface directed toward the object side in the fifth lens group G 5 . 
   Next, numerical data of the sixth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
           
          
             
               Numerical data 6 
             
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 22.245 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 8.826 
               d2 = 3.45 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 36.134 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −26.96 
               d6 = D6 
             
             
               r7 = −114.807 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.407 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 8.98 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 126.659 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 7.716 
               d12 = 6.16 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.934 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 29.278 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 11.15 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 6.803 
               d16 = 0.1 
               Nd16 = 1.59885 
               νd16 = 6.52 
             
             
               r17 = 6.686 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 10.149 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = 93.849 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 3.04484E−05 
             
             
                 
               A6 = 2.47332E−07 
             
             
                 
               A8 = 0 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.29779E−04 
             
             
                 
               A6 = 1.94880E−05 
             
             
                 
               A8 = −2.30770E−07 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −6.90117E−04 
             
             
                 
               A6 = 1.82143E−05 
             
             
                 
               A8 = −2.09696E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.14236E−05 
             
             
                 
               A6 = 1.72782E−06 
             
             
                 
               A8 = 2.44480E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.86121E−04 
             
             
                 
               A6 = 1.02728E−05 
             
             
                 
               A8 = 8.39843E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −8.14853E−05 
             
             
                 
               A6 = 6.69357E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −7.16543E−05 
             
             
                 
               A6 = 1.04773E−05 
             
             
                 
               A8 = −1.54753E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               13.42 
               17.995 
             
             
               FNO. 
               3.21 
               5.1 
               6.43 
             
             
               D6 
               2.85 
               10.17 
               10.67 
             
             
               D10 
               10.88 
               2.65 
               0.77 
             
             
               D11 
               6.94 
               2.58 
               0.4 
             
             
               D14 
               1.17 
               12.06 
               15.56 
             
             
               D17 
               1.33 
               2.02 
               3.28 
             
             
               D19 
               4.75 
               1.39 
               0.49 
             
             
               D23 
               1.37 
               1.37 
               1.37 
             
             
                 
             
          
         
       
     
   
   Seventh Embodiment 
     FIG. 13  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a seventh embodiment of the present invention. 
     FIG. 14A ,  FIG. 14B , and  FIG. 14C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the seventh embodiment, where,  FIG. 14A  shows the state at the wide angle end,  FIG. 14B  shows the intermediate state, and  FIG. 14C  shows the state at the telephoto end. 
   The zoom lens of the seventh embodiment, as shown in  FIG. 13 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a positive meniscus lens L 151  having a convex surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stops is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the positive meniscus lens L 151  having the convex surface directed toward the object side in the fifth lens group G 5 . 
   Next, numerical data of the seventh embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
           
          
             
               Numerical data 7 
             
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 23.3 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 8.963 
               d2 = 3.66 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 43.373 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −23.569 
               d6 = D6 
             
             
               r7 = −60.807 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.844 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 9.537 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 225.725 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 7.662 
               d12 = 6.34 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.718 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 28.761 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 15.01 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 7.96 
               d16 = 0.1 
               Nd16 = 1.79525 
               νd16 = 9.95 
             
             
               r17 = 7.975 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 11.632 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = 234.357 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 2.10592E−05 
             
             
                 
               A6 = 2.04017E−07 
             
             
                 
               A8 = 0 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.74185E−04 
             
             
                 
               A6 = 1.68715E−05 
             
             
                 
               A8 = −1.96216E−07 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −5.92738E−04 
             
             
                 
               A6 = 1.71764E−05 
             
             
                 
               A8 = −2.01706E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.68932E−05 
             
             
                 
               A6 = 1.80769E−06 
             
             
                 
               A8 = 1.66788E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.22351E−04 
             
             
                 
               A6 = 1.11715E−05 
             
             
                 
               A8 = 9.20361E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.32260E−05 
             
             
                 
               A6 = 6.22598E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −5.31997E−05 
             
             
                 
               A6 = 8.76368E−06 
             
             
                 
               A8 = −1.43841E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               13.42 
               17.995 
             
             
               FNO. 
               3.45 
               5.14 
               6.51 
             
             
               D6 
               3.24 
               9.87 
               10.77 
             
             
               D10 
               13.65 
               2.39 
               0.92 
             
             
               D11 
               5.85 
               3.12 
               0.4 
             
             
               D14 
               1.48 
               11.6 
               14.74 
             
             
               D17 
               1.34 
               2.07 
               3.37 
             
             
               D19 
               4.75 
               1.33 
               0.4 
             
             
               D23 
               1.37 
               1.37 
               1.37 
             
             
                 
             
          
         
       
     
   
   Eighth Embodiment 
     FIG. 15  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to an eighth embodiment of the present invention. 
     FIG. 16A ,  FIG. 16B , and  FIG. 16C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the eighth embodiment, where,  FIG. 16A  shows the state at the wide angle end,  FIG. 16B  shows the intermediate state, and  FIG. 16C  shows the state at the telephoto end. 
   The zoom lens of the eighth embodiment, as shown in  FIG. 15 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a biconvex lens L 151 , and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the biconvex lens L 151  in the fifth lens group G 5 . 
   Next, numerical data of the eighth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
           
          
             
               Numerical data 8 
             
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 23.417 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 8.991 
               d2 = 3.7 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 42.756 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −23.653 
               d6 = D6 
             
             
               r7 = −62.454 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.820 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 9.53 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 216.48 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 7.667 
               d12 = 6.33 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.715 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 28.801 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 16.547 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 8.396 
               d16 = 0.1 
               Nd16 = 1.9712 
               νd16 = 12.88 
             
             
               r17 = 8.453 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 12.298 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = −1666.051 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.97863E−05 
             
             
                 
               A6 = 1.99130E−07 
             
             
                 
               A8 = 0 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.76063E−04 
             
             
                 
               A6 = 1.66842E−05 
             
             
                 
               A8 = −1.87307E−07 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −6.00048E−04 
             
             
                 
               A6 = 1.66821E−05 
             
             
                 
               A8 = −1.83573E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.73087E−05 
             
             
                 
               A6 = 1.83455E−06 
             
             
                 
               A8 = 1.35252E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.20573E−04 
             
             
                 
               A6 = 1.11057E−05 
             
             
                 
               A8 = 9.05706E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −7.32245E−06 
             
             
                 
               A6 = 3.35000E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −5.22378E−05 
             
             
                 
               A6 = 8.59323E−06 
             
             
                 
               A8 = −1.53966E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               13.42 
               17.995 
             
             
               FNO. 
               3.41 
               5.12 
               6.49 
             
             
               D6 
               3.39 
               9.88 
               10.83 
             
             
               D10 
               13.35 
               2.4 
               0.93 
             
             
               D11 
               6.12 
               3.14 
               0.4 
             
             
               D14 
               1.47 
               11.6 
               14.69 
             
             
               D17 
               1.34 
               2.07 
               3.38 
             
             
               D19 
               4.75 
               1.33 
               0.4 
             
             
               D23 
               1.37 
               1.37 
               1.37 
             
             
                 
             
          
         
       
     
   
   Ninth Embodiment 
     FIG. 17  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a ninth embodiment of the present invention. 
     FIG. 18A ,  FIG. 18B , and  FIG. 18C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the ninth embodiment, where,  FIG. 18A  shows the state at the wide angle end,  FIG. 18B  shows the intermediate state, and  FIG. 18C  shows the state at the telephoto end. 
   The zoom lens of the ninth embodiment, as shown in  FIG. 17 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a negative meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The negative meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a positive meniscus lens L 151  having a convex surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the negative meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the positive meniscus lens L 151  having the convex surface directed toward the object side in the fifth lens group G 5 . 
   Next, numerical data of the ninth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
           
          
             
               Numerical data 9 
             
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 23.178 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 8.968 
               d2 = 3.67 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 42.366  
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −23.47 
               d6 = D6 
             
             
               r7 = −66.184 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.725 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 9.362 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 168.719 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 7.677 
               d12 = 6.32 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.657 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 28.815 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 16.437 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 8.459 
               d16 = 0.1 
               Nd16 = 2.0512 
               νd16 = 6.28 
             
             
               r17 = 8.423 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 11.783 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = 490.283 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.89496E−05 
             
             
                 
               A6 = 1.97953E−07 
             
             
                 
               A8 = 0 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.76791E−04 
             
             
                 
               A6 = 1.68717E−05 
             
             
                 
               A8 = −1.97472E−07 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −6.09891E−04 
             
             
                 
               A6 = 1.70615E−05 
             
             
                 
               A8 = −2.17636E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.94450E−05 
             
             
                 
               A6 = 1.97650E−06 
             
             
                 
               A8 = 1.24007E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.23654E−04 
             
             
                 
               A6 = 1.11472E−05 
             
             
                 
               A8 = 9.36169E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.39579E−05 
             
             
                 
               A6 = −3.59629E−09 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −7.13942E−05 
             
             
                 
               A6 = 8.39629E−06 
             
             
                 
               A8 = −1.49327E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               13.42 
               17.994 
             
             
               FNO. 
               3.36 
               5.08 
               6.45 
             
             
               D6 
               3.34 
               9.92 
               10.92 
             
             
               D10 
               12.91 
               2.49 
               1.12 
             
             
               D11 
               6.71 
               3.27 
               0.4 
             
             
               D14 
               1.48 
               11.56 
               14.61 
             
             
               D17 
               1.34 
               2.06 
               3.36 
             
             
               D19 
               4.75 
               1.34 
               0.42 
             
             
               D23 
               1.37 
               1.37 
               1.37 
             
             
                 
             
          
         
       
     
   
   Tenth Embodiment 
     FIG. 19  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a tenth embodiment of the present invention. 
     FIG. 20A ,  FIG. 20B , and  FIG. 20C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the tenth embodiment, where,  FIG. 20A  shows the state at the wide angle end,  FIG. 20B  shows the intermediate state, and  FIG. 20C  shows the state at the telephoto end. 
   The zoom lens of the tenth embodiment, as shown in  FIG. 19 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface on the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the tenth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 10 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 56.802 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 12.142 
               d2 = 3 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 51.889 
               d5 = 2.2 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −23.711 
               d6 = 0.7 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 13.043 
               d7 = D7 
             
             
               r8 = 13.679 
               d8 = 3.5 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 0.7 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −53.854 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −10.539 
               d12 = 0.7 
               Nd12 = 1.497 
               νd12 = 81.54 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.41244 
               νd13 = 12.42 
             
             
               r14 = −67.682 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 9.594 
               d15 = 3.5 
               Nd15 = 1.6935 
               νd15 = 53.21 
             
             
               (Aspheric surface)P 
             
             
               r16 = −7.5 
               d16 = 0.7 
               Nd16 = 1.84666 
               νd16 = 23.78 
             
             
               r17 = −20.609 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 4.20147E−05 
             
             
                 
               A6 = 6.55603E−08 
             
             
                 
               A8 = 0 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.41746E−05 
             
             
                 
               A6 = −9.86817E−08 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.00540E−04 
             
             
                 
               A6 = 3.88317E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.83779E−04 
             
             
                 
               A6 = 7.02894E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.008 
               13.7 
               17.997 
             
             
               FNO. 
               2.84 
               3.39 
               3.74 
             
             
               D7 
               13.77 
               4.96 
               0.8 
             
             
               D10 
               1.6 
               10.41 
               14.57 
             
             
               D11 
               1.4 
               7.75 
               9.83 
             
             
               D14 
               7.48 
               4.76 
               3 
             
             
               D17 
               5.16 
               1.53 
               1.21 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Eleventh Embodiment 
     FIG. 21  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to an eleventh embodiment of the present invention. 
     FIG. 22A ,  FIG. 22B , and  FIG. 22C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the eleventh embodiment, where,  FIG. 22A  shows the state at the wide angle end,  FIG. 22B  shows the intermediate state, and  FIG. 22C  shows the state at the telephoto end. 
   The zoom lens of the eleventh embodiment, as shown in  FIG. 21 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the eleventh embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 11 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 43.615 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 11.601 
               d2 = 3 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 64.688 
               d5 = 2.2 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −24.638 
               d6 = 0.7 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 13.439 
               d7 = D7 
             
             
               r8 = 13.774 
               d8 = 3.5 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 0.7 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −45.417 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −10.952 
               d12 = 0.7 
               Nd12 = 1.51742 
               νd12 = 52.43 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.42001 
               νd13 = 6.55 
             
             
               r14 = −69.416 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 9.645 
               d15 = 3.5 
               Nd15 = 1.6935 
               νd15 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 0.7 
               Nd16 = 1.84666 
               νd16 = 23.78 
             
             
               r17 = −21.038 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 4.60698E−05 
             
             
                 
               A6 = 9.96036E−08 
             
             
                 
               A8 = 0 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.87866E−05 
             
             
                 
               A6 = −1.30998E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.63317E−04 
             
             
                 
               A6 = 3.83985E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.69565E−04 
             
             
                 
               A6 = 6.89565E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.009 
               13.7 
               17.996 
             
             
               FNO. 
               2.84 
               3.39 
               3.74 
             
             
               D7 
               13.51 
               4.85 
               0.8 
             
             
               D10 
               1.6 
               10.27 
               14.31 
             
             
               D11 
               1.4 
               7.36 
               9.91 
             
             
               D14 
               7.63 
               5.52 
               3 
             
             
               D17 
               5.08 
               1.51 
               1.22 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Twelfth Embodiment 
     FIG. 23  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twelfth embodiment of the present invention; 
     FIG. 24A ,  FIG. 24B , and  FIG. 24C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twelfth embodiment, where,  FIG. 24A  shows the state at the wide angle end,  FIG. 24B  shows the intermediate state, and  FIG. 24C  shows the state at the telephoto end. 
   The zoom lens of the twelfth embodiment, as shown in  FIG. 23 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the twelfth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 12 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 38.631 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 10.786 
               d2 = 3 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 86.106 
               d5 = 2.2 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −17.571 
               d6 = 0.7 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 14.621 
               d7 = D7 
             
             
               r8 = 14.647 
               d8 = 3.5 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 0.7 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −50.724 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −9.942 
               d12 = 0.7 
               Nd12 = 1.51742 
               νd12 = 52.43 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.51824 
               νd13 = 12.85 
             
             
               r14 = −44.550 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 10.032 
               d15 = 3.5 
               Nd15 = 1.6935 
               νd15 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 0.7 
               Nd16 = 1.84666 
               νd16 = 23.78 
             
             
               r17 = −18.975 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 2.98434E−05 
             
             
                 
               A6 = 1.16572E−07 
             
             
                 
               A8 = 0 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.05087E−05 
             
             
                 
               A6 = −8.85285E−08 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.99506E−04 
             
             
                 
               A6 = 1.74480E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.71606E−04 
             
             
                 
               A6 = 6.39734E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.003 
               13.7 
               17.998 
             
             
               FNO. 
               2.84 
               3.39 
               3.74 
             
             
               D7 
               13.89 
               4.41 
               0.8 
             
             
               D10 
               1.6 
               11.08 
               14.69 
             
             
               D11 
               1.4 
               7.45 
               10.02 
             
             
               D14 
               7.29 
               4.65 
               3 
             
             
               D17 
               5.52 
               2.11 
               1.2 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Thirteenth Embodiment 
     FIG. 25  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirteenth embodiment of the present invention. 
     FIG. 26A ,  FIG. 26B , and  FIG. 26C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirteenth embodiment, where,  FIG. 26A  shows the state at the wide angle end,  FIG. 26B  shows the intermediate state, and  FIG. 26C  shows the state at the telephoto end. 
   The zoom lens of the thirteenth embodiment, as shown in  FIG. 25 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which his formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the thirteenth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 13 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 52.902 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 11.839 
               d2 = 3 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 59.484 
               d5 = 2.2 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −20.338 
               d6 = 0.7 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 13.453 
               d7 = D7 
             
             
               r8 = 13.734 
               d8 = 3.5 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 0.7 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −55.341 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −8.56 
               d12 = 0.7 
               Nd12 = 1.51742 
               νd12 = 52.43 
             
             
               r13 = −29.5 
               d13 = 0.35 
               Nd13 = 1.54856 
               νd13 = 7.04 
             
             
               r14 = −26.550 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 10.993 
               d15 = 3.5 
               Nd15 = 1.6935 
               νd15 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.2 
               d16 = 0.7 
               Nd16 = 1.84666 
               νd16 = 23.78 
             
             
               r17 = −16.267 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 2.68146E−05 
             
             
                 
               A6 = 1.18119E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.10592E−05 
             
             
                 
               A6 = −1.09460E−07 
             
             
                 
               A8 = −4.21441E−07 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.39397E−04 
             
             
                 
               A6 = 2.16289E−06 
             
             
                 
               A8 = −1.28129E−06 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.85478E−04 
             
             
                 
               A6 = 5.83204E−07 
             
             
                 
               A8 = 5.27383E−08 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               5.998 
               13.698 
               17.988 
             
             
               FNO. 
               2.84 
               3.4 
               3.75 
             
             
               D7 
               13.81 
               3.92 
               0.8 
             
             
               D10 
               1.6 
               11.5 
               14.62 
             
             
               D11 
               1.41 
               6.05 
               9.15 
             
             
               D14 
               6.49 
               4.93 
               3 
             
             
               D17 
               5.45 
               2.37 
               1.2 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Fourteenth Embodiment 
     FIG. 27  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fourteenth embodiment of the present invention. 
     FIG. 28A ,  FIG. 28B , and  FIG. 28C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fourteenth embodiment, where,  FIG. 28A  shows the state at the wide angle end,  FIG. 28B  shows the intermediate state, and  FIG. 28C  shows the state at the telephoto end. 
   The zoom lens of the fourteenth embodiment, as shown in  FIG. 27 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the fourteenth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 14 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 38.891 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 9.835 
               d2 = 3 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 60.054 
               d5 = 2.2 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −24.469 
               d6 = 0.7 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 12.862 
               d7 = D7 
             
             
               r8 = 15.353 
               d8 = 3.5 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 0.7 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −39.902 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −9.98 
               d12 = 0.7 
               Nd12 = 1.51729 
               νd12 = 65.94 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.65228 
               νd13 = 12.75 
             
             
               r14 = −48.119 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 11.111 
               d15 = 3.5 
               Nd15 = 1.6935 
               νd15 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 0.7 
               Nd16 = 1.84666 
               νd16 = 23.78 
             
             
               r17 = −22.56 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.13925E−05 
             
             
                 
               A6 = 1.71754E−07 
             
             
                 
               A8 = 0 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.78743E−05 
             
             
                 
               A6 = −1.60871E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.07707E−04 
             
             
                 
               A6 = 2.30478E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.45182E−04 
             
             
                 
               A6 = 2.31185E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.101 
               10.553 
               17.994 
             
             
               FNO. 
               3.06 
               3.65 
               5.17 
             
             
               D7 
               17.7 
               5.59 
               1.05 
             
             
               D10 
               5.85 
               9.39 
               13.35 
             
             
               D11 
               0.65 
               4.63 
               15.8 
             
             
               D14 
               5.72 
               3.86 
               2.69 
             
             
               D17 
               5.77 
               6.71 
               5.32 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Fifteenth Embodiment 
     FIG. 29  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a fifteenth embodiment of the present invention. 
     FIG. 30A ,  FIG. 30B , and  FIG. 30C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the fifteenth embodiment, where,  FIG. 30A  shows the state at the wide angle end,  FIG. 30B  shows the intermediate state, and  FIG. 30C  shows the state at the telephoto end. 
   The zoom lens of the fifteenth embodiment, as shown in  FIG. 29 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 241 . 
   Next, numerical data of the fifteenth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 15 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 57.868 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 11.248 
               d2 = 3.05 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 51.247 
               d5 = 3.42 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −24.561 
               d6 = 0.9 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 12.542 
               d7 = D7 
             
             
               r8 = 14.337 
               d8 = 7.69 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 3.98 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −50.883 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −10.713 
               d12 = 0.9 
               Nd12 = 1.52852 
               νd12 = 58.86 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.59885 
               νd13 = 6.52 
             
             
               r14 = −63.005 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 9.560 
               d15 = 4.34 
               Nd15 = 1.71237 
               νd15 = 44.16 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 3.5 
               Nd16 = 1.81657 
               νd16 = 21.77 
             
             
               r17 = −48.273 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.06374E−05 
             
             
                 
               A6 = 2.96748E−08 
             
             
                 
               A8 = 0 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.79953E−05 
             
             
                 
               A6 = −9.01187E−08 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.27739E−04 
             
             
                 
               A6 = 3.55154E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.08817E−04 
             
             
                 
               A6 = 1.61244E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.101 
               10.555 
               17.998 
             
             
               FNO. 
               3.24 
               3.5 
               4.82 
             
             
               D7 
               18.49 
               5.99 
               1.21 
             
             
               D10 
               0.91 
               7.03 
               11.89 
             
             
               D11 
               0.61 
               2.38 
               11.94 
             
             
               D14 
               6.75 
               5.1 
               4.34 
             
             
               D17 
               4.75 
               5.22 
               3.4 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Sixteenth Embodiment 
     FIG. 31  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a sixteenth embodiment of the present invention. 
     FIG. 32A ,  FIG. 32B , and  FIG. 32C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the sixteenth embodiment, where,  FIG. 32A  shows the state at the wide angle end,  FIG. 32B  shows the intermediate state, and  FIG. 32C  shows the state at the telephoto end. 
   The zoom lens of the sixteenth embodiment, as shown in  FIG. 31 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the sixteenth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 16 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 62.959 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 11.433 
               d2 = 2.98 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 50.756 
               d5 = 2.79 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −24.668 
               d6 = 0.9 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 12.505 
               d7 = D7 
             
             
               r8 = 14.492 
               d8 = 7.39 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 5.86 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −48.836 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −9.553 
               d12 = 0.9 
               Nd12 = 1.53585 
               νd12 = 55.13 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.79525 
               νd13 = 9.95 
             
             
               r14 = −44.152 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 9.226 
               d15 = 4.3 
               Nd15 = 1.70794 
               νd15 = 47.46 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 3.48 
               Nd16 = 1.82618 
               νd16 = 21.48 
             
             
               r17 = −49.212 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
               5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.09647E−05 
             
             
                 
               A6 = 1.57459E−08 
             
             
                 
               A8 = 0 
             
             
                 
               8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.80323E−05 
             
             
                 
               A6 = −6.55996E−08 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.26592E−04 
             
             
                 
               A6 = 4.19255E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.87754E−04 
             
             
                 
               A6 = 2.28630E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               10.553 
               17.995 
             
             
               FNO. 
               3.19 
               3.47 
               4.77 
             
             
               D7 
               18.27 
               5.85 
               1.19 
             
             
               D10 
               0.7 
               6.91 
               12.07 
             
             
               D11 
               0.64 
               2.49 
               12.19 
             
             
               D14 
               5.78 
               4.42 
               3.89 
             
             
               D17 
               4.69 
               5.18 
               3.29 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Seventeenth Embodiment 
     FIG. 33  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a seventeenth embodiment of the present invention. 
     FIG. 34A ,  FIG. 34B , and  FIG. 34C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the seventeenth embodiment, where,  FIG. 34A  shows the state at the wide angle end,  FIG. 34B  shows the intermediate state, and  FIG. 34C  shows the state at the telephoto end. 
   The zoom lens of the seventeenth embodiment, as shown in  FIG. 33 , has in order form an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 213 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group, a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the seventeenth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 17 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 68.079 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 11.633 
               d2 = 2.99 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 50.301 
               d5 = 2.33 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric 
             
             
               surface) 
             
             
               r6 = −24.516 
               d6 = 0.9 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 12.478 
               d7 = D7 
             
             
               r8 = 14.504 
               d8 = 7.39 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric 
             
             
               surface) 
             
             
               r9 = −12.5 
               d9 = 6.85 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −48.451 
               d10 = D10 
             
             
               r11 = Aperture 
               d11 = D11 
             
             
               stop 
             
             
               r12 = −8.927 
               d12 = 0.9 
               Nd12 = 1.53859 
               νd12 = 53.87 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.9712 
               νd13 = 12.88 
             
             
               r14 = −38.346 
               d14 = D14 
             
             
               (Aspheric 
             
             
               surface) 
             
             
               r15 = 8.915 
               d15 = 4.15 
               Nd15 = 1.70159 
               νd15 = 48.9 
             
             
               (Aspheric 
             
             
               surface) 
             
             
               r16 = −7.5 
               d16 = 3 
               Nd16 = 1.8402 
               νd16 = 21.32 
             
             
               r17 = −47.582 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
               5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 5.92982E−05 
             
             
                 
               A6 = 5.24010E−09 
             
             
                 
               A8 = 0 
             
             
                 
               8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.76559E−05 
             
             
                 
               A6 = −4.70537E−08 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.04099E−04 
             
             
                 
               A6 = 4.26752E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.50778E−04 
             
             
                 
               A6 = 2.93020E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               10.553 
               17.997 
             
             
               FNO. 
               3.12 
               3.41 
               4.64 
             
             
               D7 
               17.78 
               5.7 
               1.23 
             
             
               D10 
               0.56 
               6.93 
               12.47 
             
             
               D11 
               0.67 
               2.77 
               12.22 
             
             
               D14 
               5.2 
               3.94 
               3.41 
             
             
               D17 
               4.67 
               4.99 
               2.88 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Eighteenth Embodiment 
     FIG. 35  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to an eighteenth embodiment of the present invention. 
     FIG. 36A ,  FIG. 36B , and  FIG. 36C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the eighteenth embodiment, where,  FIG. 36A  shows the state at the wide angle end,  FIG. 36B  shows the intermediate state, and  FIG. 36C  shows the state at the telephoto end. 
   The zoom lens of the eighteenth embodiment, as shown in  FIG. 35 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens. L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the eighteenth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 18 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 63.79 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 11.649 
               d2 = 3.06 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 46.980 
               d5 = 3.3 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −25.318 
               d6 = 0.9 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 12.314 
               d7 = D7 
             
             
               r8 = 14.146 
               d8 = 7.85 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 4.47 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −53.448 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −9.716 
               d12 = 0.9 
               Nd12 = 1.53062 
               νd12 = 57.73 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 2.0512 
               νd13 = 6.28 
             
             
               r14 = −76.868 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 8.784 
               d15 = 4.06 
               Nd15 = 1.70975 
               νd15 = 45.62 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 3.07 
               Nd16 = 1.82469 
               νd16 = 21.99 
             
             
               r17 = −41.356 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
               5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 5.85091E−05 
             
             
                 
               A6 = 1.63330E−08 
             
             
                 
               A8 = 0 
             
             
                 
               8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.75473E−05 
             
             
                 
               A6 = −8.44888E−08 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.99314E−04 
             
             
                 
               A6 = 3.36694E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.61178E−04 
             
             
                 
               A6 = 1.58918E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.099 
               10.552 
               17.993 
             
             
               FNO. 
               3.03 
               3.33 
               4.5 
             
             
               D7 
               17.47 
               5.63 
               1.2 
             
             
               D10 
               1.14 
               7.24 
               12.69 
             
             
               D11 
               0.62 
               2.75 
               11.06 
             
             
               D14 
               6.52 
               5.15 
               4.63 
             
             
               D17 
               4.84 
               5.06 
               3.15 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Nineteenth Embodiment 
     FIG. 37  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a nineteenth embodiment of the present invention. 
     FIG. 38A ,  FIG. 38B , and  FIG. 38C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the nineteenth embodiment of the present invention, where,  FIG. 38A  shows the state at the wide angle end,  FIG. 38B  shows the intermediate state, and  FIG. 38C  shows the state at the telephoto end. 
   The zoom lens of the nineteenth embodiment, as shown in  FIG. 37 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a biconvex lens L 151 , and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the biconvex lens L 151  in the fifth lens group G 5 . 
   Next, numerical data of the nineteenth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 19 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 26.33 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 10.006 
               d2 = 2.9 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 26.758 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −28.965 
               d6 = D6 
             
             
               r7 = −131.345 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 5.919 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 8.064 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 66.381 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 7.833 
               d12 = 5.8 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.499 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 30.622 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 40.578 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 10.949 
               d16 = 0.1 
               Nd16 = 1.60687 
               νd16 = 27.03 
             
             
               r17 = 12.043 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 13.800 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = −43.765 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
               5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 4.05861E−06 
             
             
                 
               A6 = 2.45198E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.70360E−04 
             
             
                 
               A6 = 2.03291E−05 
             
             
                 
               A8 = −5.16020E−07 
             
             
                 
               8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −8.18468E−04 
             
             
                 
               A6 = 2.71936E−05 
             
             
                 
               A8 = −1.40721E−06 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.26362E−04 
             
             
                 
               A6 = 1.67158E−06 
             
             
                 
               A8 = 5.21583E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.68617E−04 
             
             
                 
               A6 = 5.97869E−06 
             
             
                 
               A8 = 9.78572E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.49229E−04 
             
             
                 
               A6 = −4.05344E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 5.20616E−05 
             
             
                 
               A6 = 3.84073E−06 
             
             
                 
               A8 = −1.76970E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.005 
               13.699 
               17.995 
             
             
               FNO. 
               2.85 
               4.82 
               5.88 
             
             
               D6 
               0.8 
               6.91 
               8.38 
             
             
               D10 
               8.97 
               2.86 
               1.39 
             
             
               D11 
               11.32 
               3.77 
               1.19 
             
             
               D14 
               1.71 
               11.94 
               14.15 
             
             
               D17 
               1.32 
               2.04 
               3.26 
             
             
               D19 
               4.76 
               1.36 
               0.51 
             
             
               D23 
               1.36 
               1.37 
               1.36 
             
             
                 
             
          
         
       
     
   
   Twentieth Embodiment 
     FIG. 39  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twentieth embodiment of the present invention. 
     FIG. 40A ,  FIG. 40B , and  FIG. 40C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twentieth embodiment, where,  FIG. 40A  shows the state at the wide angle end,  FIG. 40B  shows the intermediate state, and  FIG. 40C  shows the state at the telephoto end. 
   The zoom lens of the twentieth embodiment, as shown in  FIG. 39 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a biconvex lens L 151 , and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the biconvex lens L 151  in the fifth lens group G 5 . 
   Next, numerical data of the twentieth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 20 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 30.613 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 10.004 
               d2 = 2.9 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 25.367 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −30.821 
               d6 = D6 
             
             
               r7 = −139.143 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.251 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 8.353 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 89.717 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 8.190 
               d12 = 5.96 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.471 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 27.082 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 30.851 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 10.858 
               d16 = 0.1 
               Nd16 = 1.60258 
               νd16 = 18.58 
             
             
               r17 = 11.942 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 12.917 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = −39.589 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
               5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.11418E−05 
             
             
                 
               A6 = 7.82363E−08 
             
             
                 
               A8 = 0 
             
             
                 
               7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 3.05928E−06 
             
             
                 
               A6 = 5.15862E−06 
             
             
                 
               A8 = −1.60243E−07 
             
             
                 
               8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.11351E−04 
             
             
                 
               A6 = 7.68460E−06 
             
             
                 
               A8 = −6.23664E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 8.68188E−05 
             
             
                 
               A6 = 3.96805E−06 
             
             
                 
               A8 = −9.06844E−09 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 5.70877E−04 
             
             
                 
               A6 = 1.11773E−05 
             
             
                 
               A8 = 6.97910E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 2.53040E−04 
             
             
                 
               A6 = −4.57584E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 9.09876E−05 
             
             
                 
               A6 = 1.42880E−07 
             
             
                 
               A8 = −2.35059E−08 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               5.998 
               13.7 
               17.982 
             
             
               FNO. 
               2.85 
               4.5 
               5.64 
             
             
               D6 
               0.8 
               9.32 
               10.33 
             
             
               D10 
               10.89 
               2.37 
               1.36 
             
             
               D11 
               11.09 
               4 
               1.16 
             
             
               D14 
               1.71 
               11.67 
               15.59 
             
             
               D17 
               2.54 
               2.18 
               2.61 
             
             
               D19 
               4.54 
               2.03 
               0.53 
             
             
               D23 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Twenty First Embodiment 
     FIG. 41  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty first embodiment of the present invention. 
     FIG. 42A ,  FIG. 42B , and  FIG. 42C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty first embodiment, where,  FIG. 42A  shows the state at the wide angle end,  FIG. 42B  shows the intermediate state, and  FIG. 42C  shows the state at the telephoto end. 
   The zoom lens of the twenty first embodiment, as shown in  FIG. 41 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a biconvex lens L 151 , and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the biconvex lens L 151  in the fifth lens group G 5 . 
   Next, numerical data of the twenty first embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 21 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 26.323 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 10.008 
               d2 = 2.9 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 26.751 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric 
             
             
               surface) 
             
             
               r6 = −28.956 
               d6 = D6 
             
             
               r7 = −131.499 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric 
             
             
               surface) 
             
             
               r8 = 5.919 
               d8 = 0.7 
             
             
               (Aspheric 
             
             
               surface) 
             
             
               r9 = 8.063 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 66.411 
               d10 = D10 
             
             
               r11 = Aperture 
               d11 = D11 
             
             
               stop 
             
             
               r12 = 7.833 
               d12 = 5.8 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric 
             
             
               surface) 
             
             
               r13 = −11.499 
               d13 = 0.7 
               d13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 30.626 
               d14 = D14 
             
             
               (Aspheric 
             
             
               surface) 
             
             
               r15 = 40.611 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 10.951 
               d16 = 0.1 
               Nd16 = 1.69556 
               νd16 = 25.02 
             
             
               r17 = 12.040 
               d17 = D17 
             
             
               (Aspheric 
             
             
               surface) 
             
             
               r18 = 13.804 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric 
             
             
               surface) 
             
             
               r19 = −43.815 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
               5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 4.79969E−06 
             
             
                 
               A6 = 1.77649E−07 
             
             
                 
               A8 = 0 
             
             
                 
               7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.70126E−04 
             
             
                 
               A6 = 2.07943E−05 
             
             
                 
               A8 = −5.46313E−07 
             
             
                 
               8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −8.17289E−04 
             
             
                 
               A6 = 2.67093E−05 
             
             
                 
               A8 = −1.44560E−06 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.26495E−04 
             
             
                 
               A6 = 1.60044E−06 
             
             
                 
               A8 = 5.40471E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.67067E−04 
             
             
                 
               A6 = 5.64377E−06 
             
             
                 
               A8 = 1.00057E−06 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.47554E−04 
             
             
                 
               A6 = −4.25967E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 5.40303E−05 
             
             
                 
               A6 = 4.23811E−06 
             
             
                 
               A8 = −1.98225E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               5.971 
               13.646 
               17.936 
             
             
               FNO. 
               2.83 
               4.8 
               5.86 
             
             
               D6 
               0.8 
               6.91 
               8.38 
             
             
               D10 
               8.97 
               2.86 
               1.39 
             
             
               D11 
               11.32 
               3.77 
               1.19 
             
             
               D14 
               1.71 
               11.94 
               14.15 
             
             
               D17 
               1.32 
               2.04 
               3.26 
             
             
               D19 
               4.76 
               1.36 
               0.51 
             
             
               D23 
               1.28 
               1.3 
               1.28 
             
             
                 
             
          
         
       
     
   
   Twenty Second Embodiment 
     FIG. 43  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty second embodiment of the present invention. 
     FIG. 44A ,  FIG. 44B , and  FIG. 44C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty second embodiment, where,  FIG. 44A  shows the state at the wide angle end,  FIG. 44B  shows the intermediate state, and  FIG. 44C  shows the state at the telephoto end. 
   The zoom lens of the twenty second embodiment, as shown in  FIG. 43 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a biconvex lens L 151 , and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface on the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the biconvex lens L 151  in the fifth lens group G 5 . 
   Next, numerical data of the twenty second embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 22 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 32.631 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 9.985 
               d2 = 2.9 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 25.505 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −31.527 
               d6 = D6 
             
             
               r7 = −151.509 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.307 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 8.373 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 87.071 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 8.110 
               d12 = 6.01 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.313 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 26.936 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 34.857 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 11.538 
               d16 = 0.1 
               Nd16 = 1.72568 
               νd16 = 18.68 
             
             
               r17 = 12.691 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 13.654 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = −43.21 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.81895E−06 
             
             
                 
               A6 = 1.57853E−07 
             
             
                 
               A8 = 0 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −1.70993E−06 
             
             
                 
               A6 = 2.36923E−06 
             
             
                 
               A8 = −8.61161E−08 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.29439E−04 
             
             
                 
               A6 = 4.30202E−06 
             
             
                 
               A8 = −4.88617E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 8.07503E−05 
             
             
                 
               A6 = 3.66307E−06 
             
             
                 
               A8 = −3.68004E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.11551E−04 
             
             
                 
               A6 = 1.35724E−05 
             
             
                 
               A8 = 4.04446E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.30946E−05 
             
             
                 
               A6 = −2.52309E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −7.62235E−06 
             
             
                 
               A6 = −2.71920E−07 
             
             
                 
               A8 = −2.83588E−09 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.02 
               13.7 
               17.993 
             
             
               FNO. 
               2.85 
               4.35 
               5.45 
             
             
               D6 
               0.8 
               10.48 
               11.56 
             
             
               D10 
               12.16 
               2.48 
               1.4 
             
             
               D11 
               10.47 
               4.03 
               1.19 
             
             
               D14 
               1.69 
               11.35 
               15.31 
             
             
               D17 
               2.99 
               2.24 
               2.67 
             
             
               D19 
               4.54 
               2.06 
               0.5 
             
             
               D23 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Twenty Third Embodiment 
     FIG. 45  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty third embodiment of the present invention. 
     FIG. 46A ,  FIG. 46B , and  FIG. 46C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty third embodiment, where,  FIG. 46A  shows the state at the wide angle end,  FIG. 46B  shows the intermediate state, and  FIG. 46C  shows the state at the telephoto end. 
   The zoom lens of the twenty third embodiment, as shown in  FIG. 45 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a biconvex lens L 151 , and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the biconvex lens L 151  in the fifth lens group G 5 . 
   Next, numerical data of the twenty third embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 23 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 34.223 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 9.992 
               d2 = 2.9 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 25.219 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −31.093 
               d6 = D6 
             
             
               r7 = −171.219 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.240 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 8.367 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 94.233 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 8.110 
               d12 = 6.14 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −10.501 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 27.402 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 35.798 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 11.909 
               d16 = 0.1 
               Nd16 = 1.852 
               νd16 = 14.02 
             
             
               r17 = 13.099 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 14.223 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = −42.909 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.45893E−06 
             
             
                 
               A6 = 1.37910E−07 
             
             
                 
               A8 = 0 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.12805E−06 
             
             
                 
               A6 = 1.24854E−06 
             
             
                 
               A8 = −5.50277E−08 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.36684E−04 
             
             
                 
               A6 = 1.67990E−06 
             
             
                 
               A8 = −4.39469E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.11651E−05 
             
             
                 
               A6 = 4.18868E−06 
             
             
                 
               A8 = −7.13660E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 5.75134E−04 
             
             
                 
               A6 = 1.71545E−05 
             
             
                 
               A8 = 1.92117E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 3.19443E−05 
             
             
                 
               A6 = −2.58744E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −1.27513E−06 
             
             
                 
               A6 = −4.93312E−08 
             
             
                 
               A8 = −9.86622E−09 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.026 
               13.701 
               17.994 
             
             
               FNO. 
               2.85 
               4.22 
               5.29 
             
             
               D6 
               0.8 
               11.11 
               12.22 
             
             
               D10 
               12.81 
               2.5 
               1.4 
             
             
               D11 
               10.02 
               4 
               1.19 
             
             
               D14 
               1.7 
               10.83 
               14.52 
             
             
               D17 
               2.97 
               2.24 
               2.94 
             
             
               D19 
               4.47 
               2.09 
               0.5 
             
             
               D23 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Twenty Fourth Embodiment 
     FIG. 47  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty fourth embodiment of the present invention. 
     FIG. 48A ,  FIG. 48B , and  FIG. 48C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty fourth embodiment, where,  FIG. 48A  shows the state at the wide angle end,  FIG. 48B  shows the intermediate state, and  FIG. 48C  shows the state at the telephoto end. 
   The zoom lens of the twenty fourth embodiment, as shown in  FIG. 47 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a positive meniscus lens L 151  having a convex surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the positive meniscus lens L 151  having the convex surface directed toward the object side in the fifth lens group G 5 . 
   Next, numerical data of the twenty fourth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 24 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 25.378 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 9.203 
               d2 = 3.71 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 47.204 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −22.238 
               d6 = D6 
             
             
               r7 = −59.956 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.912 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 9.696 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 218.437 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 7.687 
               d12 = 6.26 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −12.317 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 29.010 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 15.343 
               d15 = 0.6 
               Nd15 = 1.58267 
               νd15 = 46.42 
             
             
               r16 = 7.801 
               d16 = 0.1 
               Nd16 = 1.65228 
               νd16 = 12 
             
             
               r17 = 7.969 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 10.663 
               d18 = 1.8 
               Nd18 = 1.7725 
               νd18 = 49.6 
             
             
               (Aspheric surface) 
             
             
               r19 = 182.013 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.56293E−05 
             
             
                 
               A6 = 1.88151E−07 
             
             
                 
               A8 = 0 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.52622E−04 
             
             
                 
               A6 = 1.94506E−05 
             
             
                 
               A8 = −2.27135E−07 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −6.69309E−04 
             
             
                 
               A6 = 1.97817E−05 
             
             
                 
               A8 = −2.00038E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.43312E−05 
             
             
                 
               A6 = 1.49461E−06 
             
             
                 
               A8 = 2.68705E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.23485E−04 
             
             
                 
               A6 = 9.02163E−06 
             
             
                 
               A8 = 9.80727E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.18056E−06 
             
             
                 
               A6 = 2.05787E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.12291E−05 
             
             
                 
               A6 = 9.09050E−06 
             
             
                 
               A8 = −1.55608E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               13.42 
               17.995 
             
             
               FNO. 
               3.37 
               5.23 
               6.58 
             
             
               D6 
               3.92 
               9.22 
               9.7 
             
             
               D10 
               12.74 
               2.46 
               0.47 
             
             
               D11 
               6.15 
               2.51 
               0.43 
             
             
               D14 
               1.57 
               12.09 
               15.5 
             
             
               D17 
               1.33 
               2 
               3.24 
             
             
               D19 
               4.75 
               1.4 
               0.53 
             
             
               D23 
               1.37 
               1.37 
               1.37 
             
             
                 
             
          
         
       
     
   
   Twenty Fifth Embodiment 
     FIG. 49  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty fifth embodiment of the present invention. 
     FIG. 50A ,  FIG. 50B , and  FIG. 50C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty fifth embodiment, where,  FIG. 50A  shows the state at the wide angle end,  FIG. 50B  shows the intermediate state, and  FIG. 50C  shows the state at the telephoto end. 
   The zoom lens of the twenty fifth embodiment, as shown in  FIG. 49 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a negative meniscus lens L 141  having a convex surface directed toward the object side and a negative meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The negative meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a positive meniscus lens L 151  having a convex surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface on the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the negative meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the positive meniscus lens L 151  having the convex surface directed toward the object side in the fifth lens group. G 5 . 
   Next, numerical data of the twenty fifth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 25 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 22.245 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 8.826 
               d2 = 3.45 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 36.134 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −26.96 
               d6 = D6 
             
             
               r7 = −114.807 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.407 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 8.98 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 126.659 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 7.716 
               d12 = 6.16 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.934 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 29.278 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 11.15 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 6.803 
               d16 = 0.1 
               Nd16 = 1.59885 
               νd16 = 6.52 
             
             
               r17 = 6.686 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 10.149 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = 93.849 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 3.04484E−05 
             
             
                 
               A6 = 2.47332E−07 
             
             
                 
               A8 = 0 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.29779E−04 
             
             
                 
               A6 = 1.94880E−05 
             
             
                 
               A8 = −2.30770E−07 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −6.90117E−04 
             
             
                 
               A6 = 1.82143E−05 
             
             
                 
               A8 = −2.09696E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.14236E−05 
             
             
                 
               A6 = 1.72782E−06 
             
             
                 
               A8 = 2.44480E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.86121E−04 
             
             
                 
               A6 = 1.02728E−05 
             
             
                 
               A8 = 8.39843E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −8.14853E−05 
             
             
                 
               A6 = 6.69357E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −7.16543E−05 
             
             
                 
               A6 = 1.04773E−05 
             
             
                 
               A8 = −1.54753E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               13.42 
               17.995 
             
             
               FNO. 
               3.21 
               5.1 
               6.43 
             
             
               D6 
               2.85 
               10.17 
               10.67 
             
             
               D10 
               10.88 
               2.65 
               0.77 
             
             
               D11 
               6.94 
               2.58 
               0.4 
             
             
               D14 
               1.17 
               12.06 
               15.56 
             
             
               D17 
               1.33 
               2.02 
               3.28 
             
             
               D19 
               4.75 
               1.39 
               0.49 
             
             
               D23 
               1.37 
               1.37 
               1.37 
             
             
                 
             
          
         
       
     
   
   Twenty Sixth Embodiment 
     FIG. 51  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty sixth embodiment of the present invention. 
     FIG. 52A ,  FIG. 52B , and  FIG. 52C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty sixth embodiment, where,  FIG. 52A  shows the state at the wide angle end,  FIG. 52B  shows the intermediate state, and  FIG. 52C  shows the state at the telephoto end. 
   The zoom lens of the twenty sixth embodiment, as shown in  FIG. 51 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a positive meniscus lens L 151  having a convex surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the positive meniscus lens L 151  having the convex surface directed toward the object side in the fifth lens group G 5 . 
   Next, numerical data of the twenty sixth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 26 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 23.3 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 8.963 
               d2 = 3.66 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 43.373 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −23.569 
               d6 = D6 
             
             
               r7 = −60.807 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.844 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 9.537 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 225.725 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d12 = D11 
             
             
               r12 = 7.662 
               d12 = 6.34 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.718 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 28.761 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 15.01 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 7.96 
               d16 = 0.1 
               Nd16 = 1.79525 
               νd16 = 9.95 
             
             
               r17 = 7.975 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 11.632 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = 234.357 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 2.10592E−05 
             
             
                 
               A6 = 2.04017E−07 
             
             
                 
               A8 = 0 
             
             
                 
                7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.74185E−04 
             
             
                 
               A6 = 1.68715E−05 
             
             
                 
               A8 = −1.96216E−07 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −5.92738E−04 
             
             
                 
               A6 = 1.71764E−05 
             
             
                 
               A8 = −2.01706E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.68932E−05 
             
             
                 
               A6 = 1.80769E−06 
             
             
                 
               A8 = 1.66788E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.22351E−04 
             
             
                 
               A6 = 1.11715E−05 
             
             
                 
               A8 = 9.20361E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.32260E−05 
             
             
                 
               A6 = 6.22598E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −5.31997E−05 
             
             
                 
               A6 = 8.76368E−06 
             
             
                 
               A8 = −1.43841E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               13.42 
               17.995 
             
             
               FNO. 
               3.45 
               5.14 
               6.51 
             
             
               D6 
               3.24 
               9.87 
               10.77 
             
             
               D10 
               13.65 
               2.39 
               0.92 
             
             
               D11 
               5.85 
               3.12 
               0.4 
             
             
               D14 
               1.48 
               11.6 
               14.74 
             
             
               D17 
               1.34 
               2.07 
               3.37 
             
             
               D19 
               4.75 
               1.33 
               0.4 
             
             
               D23 
               1.37 
               1.37 
               1.37 
             
             
                 
             
          
         
       
     
   
   Twenty Seventh Embodiment 
     FIG. 53  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty seventh embodiment of the present invention. 
     FIG. 54A ,  FIG. 54B , and  FIG. 54C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty seventh embodiment, where,  FIG. 54A  shows the state at the wide angle end,  FIG. 54B  shows the intermediate state, and  FIG. 54C  shows the state at the telephoto end. 
   The zoom lens of the twenty seventh embodiment, as shown in  FIG. 53 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a positive meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a biconvex lens L 151 , and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the biconcave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the positive meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the biconvex lens L 151  in the fifth lens group G 5 . 
   Next, numerical data of the twenty seventh embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 27 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 23.417 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 8.991 
               d2 = 3.7 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 42.756 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −23.653 
               d6 = D6 
             
             
               r7 = −62.454 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.820 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 9.53 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 216.48 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 7.667 
               d12 = 6.33 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.715 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 28.801 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 16.547 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 8.396 
               d16 = 0.1 
               Nd16 = 1.9712 
               νd16 = 12.88 
             
             
               r17 = 8.453 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 12.298 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = −1666.051 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
               5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.97863E−05 
             
             
                 
               A6 = 1.99130E−07 
             
             
                 
               A8 = 0 
             
             
                 
               7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.76063E−04 
             
             
                 
               A6 = 1.66842E−05 
             
             
                 
               A8 = −1.87307E−07 
             
             
                 
               8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −6.00048E−04 
             
             
                 
               A6 = 1.66821E−05 
             
             
                 
               A8 = −1.83573E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.73087E−05 
             
             
                 
               A6 = 1.83455E−06 
             
             
                 
               A8 = 1.35252E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.20573E−04 
             
             
                 
               A6 = 1.11057E−05 
             
             
                 
               A8 = 9.05706E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −7.32245E−06 
             
             
                 
               A6 = 3.35000E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −5.22378E−05 
             
             
                 
               A6 = 8.59323E−06 
             
             
                 
               A8 = −1.53966E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               13.42 
               17.995 
             
             
               FNO. 
               3.41 
               5.12 
               6.49 
             
             
               D6 
               3.39 
               9.88 
               10.83 
             
             
               D10 
               13.35 
               2.4 
               0.93 
             
             
               D11 
               6.12 
               3.14 
               0.4 
             
             
               D14 
               1.47 
               11.6 
               14.69 
             
             
               D17 
               1.34 
               2.07 
               3.38 
             
             
               D19 
               4.75 
               1.33 
               0.4 
             
             
               D23 
               1.37 
               1.37 
               1.37 
             
             
                 
             
          
         
       
     
   
   Twenty Eighth Embodiment 
     FIG. 55  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty eighth embodiment of the present invention. 
     FIG. 56A ,  FIG. 56B , and  FIG. 56C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty eighth embodiment, where,  FIG. 56A  shows the state at the wide angle end,  FIG. 56B  shows the intermediate state, and  FIG. 56C  shows the state at the telephoto end. 
   The zoom lens of the twenty eighth embodiment, as shown in  FIG. 55 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , and aperture stop S, a third lens group G 3 , a fourth lens group G 4 , and a fifth lens group G 5 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 112 , and a biconvex lens L 113 , and has a positive refracting power as a whole. 
   The second lens group G 2  includes a biconcave lens L 121  and a positive meniscus lens L 122  having a convex surface directed toward the object side, and has a negative refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a biconvex lens L 131  and a biconcave lens L 132 , and has a positive refracting power as a whole. 
   The fourth lens group G 4  includes a cemented lens which is formed by a negative meniscus lens L 141  having a convex surface directed toward the object side and a negative meniscus lens L 142  having a convex surface directed toward the object side, and has a negative refracting power as a whole. The negative meniscus lens L 142  having the convex surface directed toward the object side is a lens having a thin center-thickness. 
   The fifth lens group G 5  includes a positive meniscus lens L 151  having a convex surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward an image side, the aperture stop S is fixed, the third lens group G 3  moves toward the object side, the fourth lens group G 4  moves once toward the image side, and then moves toward the object side, and the fifth lens group G 5  moves toward the image side. 
   An aspheric surface is provided on a surface on the object side of the biconvex lens L 113  in the first lens group G 1 , both surfaces of the concave lens L 121  in the second lens group G 2 , a surface on the object side of the biconvex lens L 131  and a surface on the image side of the biconcave lens L 132  in the third lens group G 3 , a surface on the image side of the negative meniscus lens L 142  having the convex surface directed toward the object side in the fourth lens group G 4 , and a surface on the object side of the positive meniscus lens L 151  having the convex surface directed toward the object side in the fifth lens group G 5 . 
   Next, numerical data of the twenty eighth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 28 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 23.178 
               d1 = 1 
               Nd1 = 1.8061 
               νd1 = 40.92 
             
             
               r2 = 8.968 
               d2 = 3.67 
             
             
               r3 = ∞ 
               d3 = 12 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.3 
             
             
               r5 = 42.366 
               d5 = 3.54 
               Nd5 = 1.741 
               νd5 = 52.64 
             
             
               (Aspheric surface) 
             
             
               r6 = −23.47 
               d6 = D6 
             
             
               r7 = −66.184 
               d7 = 0.8 
               Nd7 = 1.8061 
               νd7 = 40.92 
             
             
               (Aspheric surface) 
             
             
               r8 = 6.725 
               d8 = 0.7 
             
             
               (Aspheric surface) 
             
             
               r9 = 9.362 
               d9 = 2.2 
               Nd9 = 1.7552 
               νd9 = 27.51 
             
             
               r10 = 168.719 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = 7.677 
               d12 = 6.32 
               Nd12 = 1.6935 
               νd12 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r13 = −11.657 
               d13 = 0.7 
               Nd13 = 1.84666 
               νd13 = 23.78 
             
             
               r14 = 28.815 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 16.437 
               d15 = 0.6 
               Nd15 = 1.48749 
               νd15 = 70.23 
             
             
               r16 = 8.459 
               d16 = 0.1 
               Nd16 = 2.0512 
               νd16 = 6.28 
             
             
               r17 = 8.423 
               d17 = D17 
             
             
               (Aspheric surface) 
             
             
               r18 = 11.783 
               d18 = 1.8 
               Nd18 = 1.7432 
               νd18 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r19 = 490.283 
               d19 = D19 
             
             
               r20 = ∞ 
               d20 = 1.9 
               Nd20 = 1.54771 
               νd20 = 62.84 
             
             
               r21 = ∞ 
               d21 = 0.8 
             
             
               r22 = ∞ 
               d22 = 0.75 
               Nd22 = 1.51633 
               νd22 = 64.14 
             
             
               r23 = ∞ 
               d23 = D23 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
               5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.89496E−05 
             
             
                 
               A6 = 1.97953E−07 
             
             
                 
               A8 = 0 
             
             
                 
               7th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.76791E−04 
             
             
                 
               A6 = 1.68717E−05 
             
             
                 
               A8 = −1.97472E−07 
             
             
                 
               8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −6.09891E−04 
             
             
                 
               A6 = 1.70615E−05 
             
             
                 
               A8 = −2.17636E−07 
             
             
                 
               12th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.94450E−05 
             
             
                 
               A6 = 1.97650E−06 
             
             
                 
               A8 = 1.24007E−08 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.23654E−04 
             
             
                 
               A6 = 1.11472E−05 
             
             
                 
               A8 = 9.36169E−07 
             
             
                 
               17th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.39579E−05 
             
             
                 
               A6 = −3.59629E−09 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               18th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −7.13942E−05 
             
             
                 
               A6 = 8.39629E−06 
             
             
                 
               A8 = −1.49327E−07 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               13.42 
               17.994 
             
             
               FNO. 
               3.36 
               5.08 
               6.45 
             
             
               D6 
               3.34 
               9.92 
               10.92 
             
             
               D10 
               12.91 
               2.49 
               1.12 
             
             
               D11 
               6.71 
               3.27 
               0.4 
             
             
               D14 
               1.48 
               11.56 
               14.61 
             
             
               D17 
               1.34 
               2.06 
               3.36 
             
             
               D19 
               4.75 
               1.34 
               0.42 
             
             
               D23 
               1.37 
               1.37 
               1.37 
             
             
                 
             
          
         
       
     
   
   Twenty Ninth Embodiment 
     FIG. 57  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a twenty ninth embodiment of the present invention. 
     FIG. 58A ,  FIG. 58B , and  FIG. 58C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the twenty ninth embodiment, where,  FIG. 58A  shows the state at the wide angle end,  FIG. 58B  shows the intermediate state, and  FIG. 58C  shows the state at the telephoto end. 
   The zoom lens of the twenty ninth embodiment, as shown in  FIG. 57 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the twenty ninth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 29 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 53.184 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 11.873 
               d2 = 3 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 59.366 
               d5 = 2.2 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −20.517 
               d6 = 0.7 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 13.429 
               d7 = D7 
             
             
               r8 = 13.703 
               d8 = 3.5 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 0.7 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −54.992 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −8.545 
               d12 = 0.7 
               Nd12 = 1.51742 
               νd12 = 52.43 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.60687 
               νd13 = 27.03 
             
             
               r14 = −29.442 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 11.068 
               d15 = 3.5 
               Nd15 = 1.6935 
               νd15 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 0.7 
               Nd16 = 1.84666 
               νd16 = 23.78 
             
             
               r17 = −16.423 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
               5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 2.67481E−05 
             
             
                 
               A6 = 1.21868E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.11732E−05 
             
             
                 
               A6 = −1.15590E−07 
             
             
                 
               A8 = −4.21441E−07 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.07942E−04 
             
             
                 
               A6 = 2.46538E−06 
             
             
                 
               A8 = −1.28129E−06 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.90469E−04 
             
             
                 
               A6 = 3.87680E−07 
             
             
                 
               A8 = 5.27383E−08 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               5.999 
               13.697 
               17.987 
             
             
               FNO. 
               2.84 
               3.39 
               3.74 
             
             
               D7 
               13.8 
               3.92 
               0.8 
             
             
               D10 
               1.6 
               11.49 
               14.61 
             
             
               D11 
               1.41 
               6.01 
               9.1 
             
             
               D14 
               6.45 
               4.93 
               3 
             
             
               D17 
               5.45 
               2.36 
               1.2 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Thirtieth Embodiment 
     FIG. 59  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirtieth embodiment of the present invention. 
     FIG. 60A ,  FIG. 60B , and  FIG. 60C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirtieth embodiment, where,  FIG. 60A  shows the state at the wide angle end,  FIG. 60B  shows the intermediate state, and  FIG. 60C  shows the state at the telephoto end. 
   The zoom lens of the thirtieth embodiment, as shown in  FIG. 59 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 111  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having the convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface on the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the thirtieth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 30 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 37.87 
               d1 = 1.1 
               Nd1 = 1.72 
               νd1 = 41.98 
             
             
               r2 = 10.224 
               d2 = 3 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 89.903 
               d5 = 2.2 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −14.853 
               d6 = 0.7 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 14.608 
               d7 = D7 
             
             
               r8 = 14.897 
               d8 = 3.5 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 0.7 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −58.416 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −8.762 
               d12 = 0.7 
               Nd12 = 1.51742 
               νd12 = 52.43 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.60258 
               νd13 = 18.58 
             
             
               r14 = −31.451 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 10.327 
               d15 = 3.5 
               Nd15 = 1.6935 
               νd15 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 0.7 
               Nd16 = 1.84666 
               νd16 = 23.78 
             
             
               r17 = −17.752 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
               5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 1.56745E−05 
             
             
                 
               A6 = 1.40375E−07 
             
             
                 
               A8 = 0 
             
             
                 
               8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −5.42647E−06 
             
             
                 
               A6 = −8.38801E−08 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.46472E−04 
             
             
                 
               A6 = −2.77422E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.66703E−04 
             
             
                 
               A6 = 2.98736E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.02 
               13.7 
               17.998 
             
             
               FNO. 
               2.84 
               3.52 
               3.89 
             
             
               D7 
               14.02 
               3.96 
               0.8 
             
             
               D10 
               1.6 
               11.67 
               14.82 
             
             
               D11 
               1.4 
               7.11 
               10.07 
             
             
               D14 
               7.1 
               4.6 
               3 
             
             
               D17 
               5.76 
               2.55 
               1.19 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Thirty First Embodiment 
     FIG. 61  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty first embodiment of the present invention. 
     FIG. 62A ,  FIG. 62B , and  FIG. 62C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty first embodiment, where,  FIG. 62A  shows the state at the wide angle end,  FIG. 62B  shows the intermediate state, and  FIG. 62C  shows the state at the telephoto end. 
   The zoom lens of the thirty first embodiment, as shown in  FIG. 61 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface toward the object side of the biconvex lens L 221  in the second lens group G 2 , a surface toward the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface toward the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the thirty first embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 31 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 53.073 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 11.88 
               d2 = 3 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 59.240 
               d5 = 2.2 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −20.497 
               d6 = 0.7 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 13.436 
               d7 = D7 
             
             
               r8 = 13.696 
               d8 = 3.5 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 0.7 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −54.875 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −8.541 
               d12 = 0.7 
               Nd12 = 1.51742 
               νd12 = 52.43 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.69556 
               νd13 = 25.02 
             
             
               r14 = −29.479 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 11.078 
               d15 = 3.5 
               Nd15 = 1.6935 
               νd15 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 0.7 
               Nd16 = 1.84666 
               νd16 = 23.78 
             
             
               r17 = −16.449 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
               5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 2.61751E−05 
             
             
                 
               A6 = 1.15939E−07 
             
             
                 
               A8 = 0 
             
             
                 
               8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.16066E−05 
             
             
                 
               A6 = −9.35544E−08 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.03099E−04 
             
             
                 
               A6 = 4.81429E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.89734E−04 
             
             
                 
               A6 = 2.36417E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               5.97 
               13.634 
               17.897 
             
             
               FNO. 
               2.82 
               3.37 
               3.71 
             
             
               D7 
               13.8 
               3.92 
               0.8 
             
             
               D10 
               1.6 
               11.49 
               14.61 
             
             
               D11 
               1.41 
               6.01 
               9.1 
             
             
               D14 
               6.45 
               4.93 
               3 
             
             
               D17 
               5.45 
               2.36 
               1.2 
             
             
               D21 
               1.1 
               1.11 
               1.12 
             
             
                 
             
          
         
       
     
   
   Thirty Second Embodiment 
     FIG. 63  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty second embodiment of the present invention. 
     FIG. 64A ,  FIG. 64B , and  FIG. 64C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty second embodiment, where,  FIG. 64A  shows the state at the wide angle end,  FIG. 64B  shows the intermediate state, and  FIG. 64C  shows the state at the telephoto end. 
   The zoom lens of the thirty second embodiment, as shown in  FIG. 63 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the thirty second embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 32 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 35.882 
               d1 = 1.1 
               Nd1 = 1.72 
               νd1 = 41.98 
             
             
               r2 = 11.389 
               d2 = 3 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 1449.208 
               d5 = 2.2 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −20.294 
               d6 = 0.7 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 13.692 
               d7 = D7 
             
             
               r8 = 13.337 
               d8 = 3.5 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 0.7 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −35.434 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −9.636 
               d12 = 0.7 
               Nd12 = 1.51742 
               νd12 = 52.43 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.72568 
               νd13 = 18.68 
             
             
               r14 = −47.470 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 9.153 
               d15 = 3.5 
               Nd15 = 1.6935 
               νd15 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 0.7 
               Nd16 = 1.84666 
               νd16 = 23.78 
             
             
               r17 = −27.617 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
               5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 4.26368E−05 
             
             
                 
               A6 = 2.02030E−07 
             
             
                 
               A8 = 0 
             
             
                 
               8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.51766E−05 
             
             
                 
               A6 = −2.67569E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.01076E−04 
             
             
                 
               A6 = 2.16748E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.54268E−04 
             
             
                 
               A6 = 2.30811E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.115 
               13.7 
               17.987 
             
             
               FNO. 
               2.84 
               3.46 
               3.75 
             
             
               D7 
               12.73 
               4.33 
               0.8 
             
             
               D10 
               1.58 
               9.99 
               13.51 
             
             
               D11 
               1.41 
               6.05 
               10.08 
             
             
               D14 
               8.06 
               6.6 
               2.98 
             
             
               D17 
               4.78 
               1.6 
               1.19 
             
             
                 
             
          
         
       
     
   
   Thirty Third Embodiment 
     FIG. 65  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty third embodiment of the present invention. 
     FIG. 66A ,  FIG. 66B , and  FIG. 66C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty third embodiment, where,  FIG. 66A  shows the state at the wide angle end,  FIG. 66B  shows the intermediate state, and  FIG. 66C  shows the state at the telephoto end. 
   The zoom lens of the thirty third embodiment, as shown in  FIG. 65 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the thirty third embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 33 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 35.571 
               d1 = 1.1 
               Nd1 = 1.72 
               νd1 = 41.98 
             
             
               r2 = 11.248 
               d2 = 3 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 610.441 
               d5 = 2.2 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −20.284 
               d6 = 0.7 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 14.001 
               d7 = D7 
             
             
               r8 = 13.614 
               d8 = 3.5 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 0.7 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −35.933 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −9.979 
               d12 = 0.7 
               Nd12 = 1.51742 
               νd12 = 52.43 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.852 
               νd13 = 14.02 
             
             
               r14 = −57.672 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 9.097 
               d15 = 3.5 
               Nd15 = 1.6935 
               νd15 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 0.7 
               Nd16 = 1.84666 
               νd16 = 23.78 
             
             
               r17 = −27.778 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 4.31813E−05 
             
             
                 
               A6 = 1.95476E−07 
             
             
                 
               A8 = 0 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.35637E−05 
             
             
                 
               A6 = −2.46996E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −1.80555E−04 
             
             
                 
               A6 = 2.30560E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −2.61526E−04 
             
             
                 
               A6 = 3.69800E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.108 
               13.7 
               17.989 
             
             
               FNO. 
               2.84 
               3.49 
               3.76 
             
             
               D7 
               12.89 
               4.45 
               0.81 
             
             
               D10 
               1.58 
               10.03 
               13.67 
             
             
               D11 
               1.41 
               6.36 
               10.13 
             
             
               D14 
               8.02 
               6.38 
               2.98 
             
             
               D17 
               4.88 
               1.58 
               1.2 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Thirty Fourth Embodiment 
     FIG. 67  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty fourth embodiment of the present invention. 
     FIG. 68A ,  FIG. 68B , and  FIG. 68C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty fourth embodiment, where,  FIG. 68A  shows the state at the wide angle end,  FIG. 68B  shows the intermediate state, and  FIG. 68  shows the state at the telephoto end. 
   The zoom lens of the thirty fourth embodiment, as shown in  FIG. 67 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the thirty fourth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 34 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 38.891 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 9.835 
               d2 = 3 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 60.054 
               d5 = 2.2 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −24.469 
               d6 = 0.7 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 12.862 
               d7 = D7 
             
             
               r8 = 15.353 
               d8 = 3.5 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 0.7 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −39.902 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −9.98 
               d12 = 0.7 
               Nd12 = 1.51729 
               νd12 = 65.94 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.65228 
               νd13 = 12.75 
             
             
               r14 = −48.119 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 11.111 
               d15 = 3.5 
               Nd15 = 1.6935 
               νd15 = 53.21 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 0.7 
               Nd16 = 1.84666 
               νd16 = 23.78 
             
             
               r17 = −22.56 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 7.13925E−05 
             
             
                 
               A6 = 1.71754E−07 
             
             
                 
               A8 = 0 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.78743E−05 
             
             
                 
               A6 = −1.60871E−07 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.07707E−04 
             
             
                 
               A6 = 2.30478E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.45182E−04 
             
             
                 
               A6 = 2.31185E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.101 
               10.553 
               17.994 
             
             
               FNO. 
               3.06 
               3.65 
               5.17 
             
             
               D7 
               17.7 
               5.59 
               1.05 
             
             
               D10 
               5.85 
               9.39 
               13.35 
             
             
               D11 
               0.65 
               4.63 
               15.8 
             
             
               D14 
               5.72 
               3.86 
               2.69 
             
             
               D17 
               5.77 
               6.71 
               5.32 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Thirty Fifth Embodiment 
     FIG. 69  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty fifth embodiment of the present invention. 
     FIG. 70A ,  FIG. 70B , and  FIG. 70C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty fifth embodiment, where,  FIG. 70A  shows the state at the wide angle end,  FIG. 70B  shows the intermediate state, and  FIG. 70C  shows the state at the telephoto end. 
   The zoom lens of the thirty fifth embodiment, as shown in  FIG. 69 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the thirty fifth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 35 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 57.868 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 11.248 
               d2 = 3.05 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 51.247 
               d5 = 3.42 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −24.561 
               d6 = 0.9 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 12.542 
               d7 = D7 
             
             
               r8 = 14.337 
               d8 = 7.69 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 3.98 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −50.883 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −10.713 
               d12 = 0.9 
               Nd12 = 1.52852 
               νd12 = 58.86 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.59885 
               νd13 = 6.52 
             
             
               r14 = −63.005 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 9.560 
               d15 = 4.34 
               Nd15 = 1.71237 
               νd15 = 44.16 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 3.5 
               Nd16 = 1.81657 
               νd16 = 21.77 
             
             
               r17 = −48.273 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.06374E−05 
             
             
                 
               A6 = 2.96748E−08 
             
             
                 
               A8 = 0 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.79953E−05 
             
             
                 
               A6 = −9.01187E−08 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.27739E−04 
             
             
                 
               A6 = 3.55154E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.08817E−04 
             
             
                 
               A6 = 1.61244E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.101 
               10.555 
               17.998 
             
             
               FNO. 
               3.24 
               3.5 
               4.82 
             
             
               D7 
               18.49 
               5.99 
               1.21 
             
             
               D10 
               0.91 
               7.03 
               11.89 
             
             
               D11 
               0.61 
               2.38 
               11.94 
             
             
               D14 
               6.75 
               5.1 
               4.34 
             
             
               D17 
               4.75 
               5.22 
               3.4 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Thirty Sixth Embodiment 
     FIG. 71  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty sixth embodiment of the present invention. 
     FIG. 72A ,  FIG. 72B , and  FIG. 72C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty sixth embodiment, where,  FIG. 72A  shows the state at the wide angle end,  FIG. 72B  shows the intermediate state, and  FIG. 72C  shows the state at the telephoto end. 
   The zoom lens of the thirty sixth embodiment, as shown in  FIG. 71 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the thirty sixth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 36 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 62.959 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 11.433 
               d2 = 2.98 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 50.756 
               d5 = 2.79 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −24.668 
               d6 = 0.9 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 12.505 
               d7 = D7 
             
             
               r8 = 14.492 
               d8 = 7.39 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 5.86 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −48.836 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −9.553 
               d12 = 0.9 
               Nd12 = 1.53585 
               νd12 = 55.13 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.79525 
               νd13 = 9.95 
             
             
               r14 = −44.152 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 9.226 
               d15 = 4.3 
               Nd15 = 1.70794 
               νd15 = 47.46 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 3.48 
               Nd16 = 1.82618 
               νd16 = 21.48 
             
             
               r17 = −49.212 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 6.09647E−05 
             
             
                 
               A6 = 1.57459E−08 
             
             
                 
               A8 = 0 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.80323E−05 
             
             
                 
               A6 = −6.55996E−08 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.26592E−04 
             
             
                 
               A6 = 4.19255E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.87754E−04 
             
             
                 
               A6 = 2.28630E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               10.553 
               17.995 
             
             
               FNO. 
               3.19 
               3.47 
               4.77 
             
             
               D7 
               18.27 
               5.85 
               1.19 
             
             
               D10 
               0.7 
               6.91 
               12.07 
             
             
               D11 
               0.64 
               2.49 
               12.19 
             
             
               D14 
               5.78 
               4.42 
               3.89 
             
             
               D17 
               4.69 
               5.18 
               3.29 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Thirty Seventh Embodiment 
     FIG. 73  is a cross-sectional view along the optical axis showing an optical arrangement at the wide angle end of a zoom lens according to a thirty seventh embodiment of the present invention. 
     FIG. 74A ,  FIG. 74B , and  FIG. 74C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty seventh embodiment, where,  FIG. 74A  shows the state at the wide angle end,  FIG. 74B  shows the intermediate state, and  FIG. 74C  shows the state at the telephoto end. 
   The zoom lens of the thirty seventh embodiment, as shown in  FIG. 73 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconcave lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the thirty seventh embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 37 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 68.079 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 11.633 
               d2 = 2.99 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 50.301 
               d5 = 2.33 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −24.516 
               d6 = 0.9 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 12.478 
               d7 = D7 
             
             
               r8 = 14.504 
               d8 = 7.39 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 6.85 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −48.451 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −8.927 
               d12 = 0.9 
               Nd12 = 1.53859 
               νd12 = 53.87 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 1.9712 
               νd13 = 12.88 
             
             
               r14 = −38.346 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 8.915 
               d15 = 4.15 
               Nd15 = 1.70159 
               νd15 = 48.9 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 3 
               Nd16 = 1.8402 
               νd16 = 21.32 
             
             
               r17 = −47.582 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 5.92982E−05 
             
             
                 
               A6 = 5.24010E−09 
             
             
                 
               A8 = 0 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.76559E−05 
             
             
                 
               A6 = −4.70537E−08 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.04099E−04 
             
             
                 
               A6 = 4.26752E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −4.50778E−04 
             
             
                 
               A6 = 2.93020E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.1 
               10.553 
               17.997 
             
             
               FNO. 
               3.12 
               3.41 
               4.64 
             
             
               D7 
               17.78 
               5.7 
               1.23 
             
             
               D10 
               0.56 
               6.93 
               12.47 
             
             
               D11 
               0.67 
               2.77 
               12.22 
             
             
               D14 
               5.2 
               3.94 
               3.41 
             
             
               D17 
               4.67 
               4.99 
               2.88 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Thirty Eighth Embodiment 
     FIG. 75  is a cross-sectional view along the optical axis showing an optical arrangement at the time of the infinite object point focusing at the wide angle end of a zoom lens according to a thirty eighth embodiment of the present invention. 
     FIG. 76A ,  FIG. 76B , and  FIG. 76C  are diagrams showing the spherical aberration, the astigmatism, the distortion, and the chromatic aberration of magnification at the time of the infinite object point focusing of the zoom lens according to the thirty eighth embodiment, where,  FIG. 76A  shows the state at the wide angle end,  FIG. 76B  shows the intermediate state, and  FIG. 76C  shows the state at the telephoto end. 
   The zoom lens of the thirty eighth embodiment, as shown in  FIG. 75 , has in order from an object side thereof, a first lens group G 1 , a second lens group G 2 , an aperture stop S, a third lens group G 3 , and a fourth lens group G 4 . In the diagram, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element. 
   The first lens group G 1  includes a negative meniscus lens L 211  having a convex surface directed toward the object side, a prism L 212 , and a cemented lens which is formed by a biconvex lens L 213  and a biconcave lens L 214 , and has a negative refracting power as a whole. 
   The second lens group G 2  includes a cemented lens which is formed by a biconvex lens L 221  and a negative meniscus lens L 222  having a convex surface directed toward an image side, and has a positive refracting power as a whole. 
   The third lens group G 3  includes a cemented lens which is formed by a negative meniscus lens L 231  having a concave surface directed toward the object side and a positive meniscus lens L 232  having a concave surface directed toward the object side, and has a negative refracting power as a whole. The positive meniscus lens L 232  having the concave surface directed toward the object side is a lens having a thin center-thickness. 
   The fourth lens group G 4  includes a cemented lens which is formed by a biconvex lens L 241  and a negative meniscus lens L 242  having a concave surface directed toward the object side, and has a positive refracting power as a whole. 
   At the time of zooming from the wide angle end to the telephoto end, the first lens group G 1  is fixed, the second lens group G 2  moves toward the object side, the aperture stop S is fixed, the third lens group G 3  moves toward the image side, and the fourth lens group G 4  moves toward the image side. 
   An aspheric surface is provided on a surface toward the object side of the biconvex lens L 213  in the first lens group G 1 , a surface on the object side of the biconvex lens L 221  in the second lens group G 2 , a surface on the image side of the positive meniscus lens L 232  having the concave surface directed toward the object side in the third lens group G 3 , and a surface on the object side of the biconvex lens L 241  in the fourth lens group G 4 . 
   Next, numerical data of the thirty eighth embodiment will be enumerated. 
   
     
       
         
             
           
             
                 
             
             
               Numerical data 38 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               r1 = 63.79 
               d1 = 1.1 
               Nd1 = 1.7432 
               νd1 = 49.34 
             
             
               r2 = 11.649 
               d2 = 3.06 
             
             
               r3 = ∞ 
               d3 = 12.5 
               Nd3 = 1.8061 
               νd3 = 40.92 
             
             
               r4 = ∞ 
               d4 = 0.4 
             
             
               r5 = 46.980 
               d5 = 3.3 
               Nd5 = 1.883 
               νd5 = 40.76 
             
             
               (Aspheric surface) 
             
             
               r6 = −25.318 
               d6 = 0.9 
               Nd6 = 1.48749 
               νd6 = 70.23 
             
             
               r7 = 12.314 
               d7 = D7 
             
             
               r8 = 14.146 
               d8 = 7.85 
               Nd8 = 1.7432 
               νd8 = 49.34 
             
             
               (Aspheric surface) 
             
             
               r9 = −12.5 
               d9 = 4.47 
               Nd9 = 1.84666 
               νd9 = 23.78 
             
             
               r10 = −53.448 
               d10 = D10 
             
             
               r11 = Aperture stop 
               d11 = D11 
             
             
               r12 = −9.716 
               d12 = 0.9 
               Nd12 = 1.53062 
               νd12 = 57.73 
             
             
               r13 = −100 
               d13 = 0.35 
               Nd13 = 2.0512 
               νd13 = 6.28 
             
             
               r14 = −76.868 
               d14 = D14 
             
             
               (Aspheric surface) 
             
             
               r15 = 8.784 
               d15 = 4.06 
               Nd15 = 1.70975 
               νd15 = 45.62 
             
             
               (Aspheric surface) 
             
             
               r16 = −7.5 
               d16 = 3.07 
               Nd16 = 1.82469 
               νd16 = 21.99 
             
             
               r17 = −41.356 
               d17 = D17 
             
             
               r18 = ∞ 
               d18 = 1.44 
               Nd18 = 1.54771 
               νd18 = 62.84 
             
             
               r19 = ∞ 
               d19 = 0.8 
             
             
               r20 = ∞ 
               d20 = 0.6 
               Nd20 = 1.51633 
               νd20 = 64.14 
             
             
               r21 = ∞ 
               d21 = D21 
             
             
                 
             
          
         
         
             
          
             
               Aspherical coefficients 
             
             
                 
             
          
         
         
             
             
          
             
                 
                5th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = 5.85091E−05 
             
             
                 
               A6 = 1.63330E−08 
             
             
                 
               A8 = 0 
             
             
                 
                8th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.75473E−05 
             
             
                 
               A6 = −8.44888E−08 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               14th surface 
             
             
                 
               k = 0 
             
             
                 
               4 = −2.99314E−04 
             
             
                 
               A6 = 3.36694E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
               15th surface 
             
             
                 
               k = 0 
             
             
                 
               A4 = −3.61178E−04 
             
             
                 
               A6 = 1.58918E−06 
             
             
                 
               A8 = 0.00000E+00 
             
             
                 
                 
             
          
         
         
             
          
             
               Zoom data 
             
             
               When D0 (distance from object up to 1st surface) is ∞ 
             
          
         
         
             
             
             
             
          
             
                 
               wide-angle end 
               intermediate 
               telephoto end 
             
             
                 
             
             
               Focal length 
               6.099 
               10.552 
               17.993 
             
             
               FNO. 
               3.03 
               3.33 
               4.5 
             
             
               D7 
               17.47 
               5.63 
               1.2 
             
             
               D10 
               1.14 
               7.24 
               12.69 
             
             
               D11 
               0.62 
               2.75 
               11.06 
             
             
               D14 
               6.52 
               5.15 
               4.63 
             
             
               D17 
               4.84 
               5.06 
               3.15 
             
             
               D21 
               1.36 
               1.36 
               1.36 
             
             
                 
             
          
         
       
     
   
   Thirty Ninth Embodiment 
   Thus, it is possible to use such image forming optical system of the present invention in a photographic apparatus in which an image of an object is photographed by an electronic image pickup element such as a CCD and a CMOS, particularly a digital camera and a video camera, a personal computer, a telephone, and a portable terminal which are examples of an information processing unit, particularly a portable telephone which is easy to carry. Embodiments thereof will be exemplified below. 
   In  FIG. 77  to  FIG. 79  show conceptual diagrams of structures in which the image forming optical system according to the present invention is incorporated in a photographic optical system  41  of a digital camera.  FIG. 77  is a frontward perspective view showing an appearance of a digital camera  40 ,  FIG. 78  is a rearward perspective view of the same, and  FIG. 79  is a cross-sectional view showing an optical arrangement of the digital camera  40 . 
   The digital camera  40 , in a case of this example, includes the photographic optical system  41  (an objective optical system for photography  48 ) having an optical path for photography  42 , a finder optical system  43  having an optical path for finder  44 , a shutter  45 , a flash  46 , and a liquid-crystal display monitor  47 . Moreover, when the shutter  45  disposed at an upper portion of the camera  40  is pressed, in conjugation with this, a photograph is taken through the photographic optical system  41  (objective optical system for photography  48 ) such as the zoom lens in the first embodiment. 
   An object image formed by the photographic optical system  41  (photographic objective optical system  48 ) is formed on an image pickup surface  50  of a CCD  49 . The object image photoreceived at the CCD  49  is displayed on the liquid-crystal display monitor  47  which is provided on a camera rear surface as an electronic image, via an image processing means  51 . Moreover, a memory etc. is disposed in the image processing means  51 , and it is possible to record the electronic image photographed. This memory may be provided separately from the image processing means  51 , or may be formed by carrying out by writing by recording (recorded writing) electronically by a floppy (registered trademark) disc, memory card, or an MO etc. 
   Furthermore, an objective optical system for finder  53  is disposed in the optical path for finder  44 . This objective optical system for finder  53  includes a cover lens  54 , a first prism  10 , an aperture stop  2 , a second prism  20 , and a lens for focusing  66 . An object image is formed on an image forming surface  67  by this objective optical system for finder  53 . This object image is formed in a field frame of a Porro prism which is an image erecting member equipped with a first reflecting surface  56  and a second reflecting surface  58 . On a rear side of this Porro prism, an eyepiece optical system  59  which guides an image formed as an erected normal image is disposed. 
   By the digital camera  40  structured in such manner, it is possible to realize an optical image pickup apparatus having a zoom lens with a reduced size and thickness, in which the number of structural components is reduced. 
   Next, a personal computer which is an example of an information processing apparatus with a built-in image forming system as an objective optical system is shown in  FIG. 80  to  FIG. 82 .  FIG. 80  is a frontward perspective view of a personal computer  300  with its cover opened,  FIG. 81  is a cross-sectional view of a photographic optical system  303  of the personal computer  300 , and  FIG. 82  is a side view of  FIG. 80 . As it is shown in  FIG. 80  to  FIG. 82 , the personal computer  300  has a keyboard  301 , an information processing means and a recording means, a monitor  302 , and a photographic optical system  303 . 
   Here, the keyboard  301  is for an operator to input information from an outside. The information processing means and the recording means are omitted in the diagram. The monitor  302  is for displaying the information to the operator. The photographic optical system  303  is for photographing an image of the operator or a surrounding. The monitor  302  may be a display such as a liquid-crystal display or a CRT display. As the liquid-crystal display, a transmission liquid-crystal display device which illuminates from a rear surface by a backlight not shown in the diagram, and a reflection liquid-crystal display device which displays by reflecting light from a front surface are available. Moreover, in the diagram, the photographic optical system  303  is built-in at a right side of the monitor  302 , but without restricting to this location, the photographic optical system  303  may be anywhere around the monitor  302  and the keyboard  301 . 
   This photographic optical system  303  has an objective optical system  100  which includes the zoom lens in the first embodiment for example, and an electronic image pickup element chip  162  which receives an image. These are built into the personal computer  300 . 
   At a front end of a mirror frame, a cover glass  102  for protecting the objective optical system  100  is disposed. 
   An object image received at the electronic image pickup element chip  162  is input to a processing means of the personal computer  300  via a terminal  166 . Further, the object image is displayed as an electronic image on the monitor  302 . In  FIG. 40 , an image  305  photographed by the user is displayed as an example of the electronic image. Moreover, it is also possible to display the image  305  on a personal computer of a communication counterpart from a remote location via a processing means. For transmitting the image to the remote location, the Internet and telephone are used. 
   Next, a telephone which is an example of an information processing apparatus in which the image forming optical system of the present invention is built-in as a photographic optical system, particularly a portable telephone which is easy to carry is shown in  FIG. 83A ,  FIG. 83B , and  FIG. 83C .  FIG. 83A  is a front view of a portable telephone  400 ,  FIG. 83B  is a side view of the portable telephone  400 , and  FIG. 83C  is a cross-sectional view of a photographic optical system  405 . As shown in  FIG. 83A  to  FIG. 83C , the portable telephone  400  includes a microphone section  401 , a speaker section  402 , an input dial  403 , a monitor  404 , the photographic optical system  405 , an antenna  406 , and a processing means. 
   Here, the microphone section  401  is for inputting a voice of the operator as information. The speaker section  402  is for outputting a voice of the communication counterpart. The input dial  403  is for the operator to input information. The monitor  404  is for displaying a photographic image of the operator himself and the communication counterpart, and information such as a telephone number. The antenna  406  is for carrying out a transmission and a reception of communication electric waves. The processing means (not shown in the diagram) is for carrying out processing of image information, communication information, and input signal etc. 
   Here, the monitor  404  is a liquid-crystal display device. Moreover, in the diagram, a position of disposing each structural element is not restricted in particular to a position in the diagram. This photographic optical system  405  has an objective optical system  100  which is disposed in a photographic optical path  407  and an image pickup element chip  162  which receives an object image. As the objective optical system  100 , the zoom lens in the first embodiment for example, is used. These are built into the portable telephone  400 . 
   At a front end of a mirror frame, a cover glass  102  for protecting the objective optical system  100  is disposed. 
   An object image received at the electronic image pickup element chip  162  is input to an image processing means which is not shown in the diagram, via a terminal  166 . Further, the object image finally displayed as an electronic image on the monitor  404  or a monitor of the communication counterpart, or both. Moreover, a signal processing function is included in the processing means. In a case of transmitting an image to the communication counterpart, according to this function, information of the object image received at the electronic image pickup element chip  162  is converted to a signal which can be transmitted. 
   As it has been described above, the image forming lens of the present invention, and the electronic image pickup apparatus in which the image forming lens is used have the following characteristics. 
   (1) It is characterized in that, instead of condition (1a), the following conditional expression is satisfied.
 
1.48&lt;β&lt;2.04
 
Here, Nd denotes a refractive index of a glass used in a cemented lens, νd denotes an Abbe&#39;s number for the glass used in the cemented lens, and a relation Nd=α×νd+β is satisfied. (2) It is characterized in that, instead of condition (1a), the following conditional expression is satisfied.
 
1.50&lt;β&lt;2.00
 
Here, Nd denotes a refractive index of the glass used in the cemented lens, νd denotes the Abbe&#39;s number for the glass used in the cemented lens, and the relation Nd=α×νd+β is satisfied.
 
(3) It is characterized in that, instead of condition (2a), the following conditional expression is satisfied.
 
1.58&lt;Nd&lt;2.10
 
Here, Nd denotes the refractive index of the glass used in the cemented lens.
 
(4) It is characterized in that, instead of condition (2a), the following conditional expression is satisfied.
 
1.63&lt;Nd&lt;1.95
 
Here, Nd denotes the refractive index of the glass used in the cemented lens.
 
(5) It is characterized in that, instead of condition (3a), the following conditional expression is satisfied.
 
5&lt;νd&lt;10
 
Here, νd denotes the Abbe&#39;s number for the glass used in the cemented lens.
 
(6) It is characterized in that, instead of condition (3a), the following conditional expression is satisfied.
 
6&lt;νd&lt;9
 
Here, νd denotes the Abbe&#39;s number for the glass used in the cemented lens.
 
(7) It is characterized in that, instead of condition (1b), the following conditional expression is satisfied.
 
1.48&lt;β&lt;2.04
 
   Here, Nd denotes the refractive index of the glass used in the cemented lens, νd denotes the Abbe&#39;s number for the glass used in the cemented lens, and the relation Nd=α×νd+β is satisfied. 
   (8) It is characterized in that, instead of condition (1b), the following conditional expression is satisfied.
 
1.50&lt;β&lt;2.00
 
Here, Nd denotes the refractive index of the glass used in the cemented lens, νd denotes the Abbe&#39;s number for the glass used in the cemented lens, and the relation Nd=α×νd+β is satisfied.
 
(9) It is characterized in that, instead of condition (2b), the following conditional expression is satisfied.
 
1.60&lt;Nd&lt;2.10
 
Here, Nd denotes the refractive index of the glass used in the cemented lens.
 
(10) It is characterized in that, instead of condition (2b), the following conditional expression is satisfied.
 
1.63&lt;Nd&lt;1.95
 
Here, Nd denotes the refractive index of the glass used in the cemented lens.
 
(11) It is characterized in that, instead of condition (3b), the following conditional expression is satisfied.
 
5&lt;νd&lt;30
 
Here, νd denotes the Abbe&#39;s number for the glass used in the cemented lens.
 
(12) It is characterized in that, instead of condition (3b), the following conditional expression is satisfied.
 
6&lt;νd&lt;0.25
 
Here, νd denotes the Abbe&#39;s number for the glass used in the cemented lens.
 
(13) It is characterized in that, instead of condition (7), the following conditional expression is satisfied at the time of almost infinite object point focusing.
 
0.75 &lt;y   07 /( fw ·tan ω 07w )&lt;0.94
 
   where, y 07  is indicated as y 07 =0.7y 10  when, in an effective image pickup surface (surface in which, image pickup is possible), a distance from a center up to a farthest point (maximum image height) is let to be y 10 . Moreover, ω 07w  is an angle with respect to an optical axis in a direction of an object point corresponding to an image point connecting from a center on the image pickup surface at a wide angle end up to a position of y 07 . 
   (14) It is characterized in that, instead of condition (7), the following conditional expression is satisfied at the time of almost infinite object point focusing.
 
0.80&lt; y   07 /( fw ·tan ω 07w )&lt;0.92
 
   where, y 07  is indicated by y 07 =0.7y 10  when, in an effective image pickup surface (surface in which, image pickup is possible), a distance from a center up to a farthest point (maximum image height) is let to be y 10 . Moreover, ω 07w  is an angle with respect to an optical axis in a direction of an object point corresponding to an image point connecting from a center on the image pickup surface in a wide angle end up to a position of y 07 . 
   The present invention can have various modified embodiments which fall within the basic teachings herein set forth 
   INDUSTRIAL APPLICABILITY 
   An image forming optical system according to the present invention is useful in an optical system with a reduced size and thickness (made thin), and furthermore, an electronic image pickup apparatus of the present invention is useful in an apparatus in which, both a favorable correction and a widening of an angle have been realized.