PATENT ABSTRACT
A zoom lens system is provided that includes a compactly constructed focusing lens unit and that has a suppressed change in the image magnification at the time of movement of a focusing lens unit. The zoom lens system according to the present invention, in order from an object side to an image side, comprises: a first lens unit having positive optical power; a second lens unit having negative optical power; and at least two subsequent lens units, wherein the at least two subsequent lens units include a lens unit A and a lens unit B arranged on the image side relative to the lens unit A, at the time of zooming, all lens units move in a direction along the optical axis so that intervals between the lens units vary, at the time of focusing, the lens unit A moves in a direction along the optical axis, and the following condition is satisfied. 
       0.10&lt;| f   BAK   /f   F |/( f   T   /f   W )&lt;15.0       (here, f T /f W &gt;4, ω W &lt;20°

PATENT DESCRIPTION
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a zoom lens system and, in particular, to a zoom lens system suitable for an imaging lens system employed in an interchangeable lens apparatus in a so-called interchangeable-lens type digital camera system (simply referred to as a “camera system”, in some cases hereinafter). Further, the present invention relates to an interchangeable lens apparatus and a camera system that employ this zoom lens system. 
         [0003]    2. Description of the Background Art 
         [0004]    The market is rapidly growing for interchangeable-lens type digital camera systems each including: a camera body employing an image sensor composed of a CCD (Charge Coupled Device), a CMOS (Complementary Metal-Oxide Semiconductor) or the like; and an interchangeable lens apparatus employing an imaging lens system for forming an optical image on the light acceptance surface of the image sensor, wherein the imaging lens system is attachable to and detachable from the camera body. As for the interchangeable lens apparatuses, those employing a zoom lens system capable of forming an optical image with variable magnification are widely favored. 
         [0005]    Among zoom lens systems, in particular, telephoto-oriented zoom lens systems have a long focal length at a telephoto limit, and hence often have a long overall optical length (a distance from the top of the lens surface on the most object side to the image surface). Thus, such a configuration is often employed that a lens unit having positive optical power is arranged on the most object side and a lens unit having negative optical power is arranged on the most image side so that the overall optical length at a telephoto limit is made shorter than the focal length at a telephoto limit. 
         [0006]    In telephoto-oriented zoom lens systems, configurations have been proposed that the number of lens units is increased for the purpose of reducing various kinds of aberration. For example, a zoom lens system consisting of five lens units of positive, negative, negative, positive and negative has been proposed (e.g., Japanese Patent Publication No. 3134448 (Reference 1)). Further, in telephoto-oriented zoom lens systems, the long focal length at a telephoto limit easily enhances image blur in association with vibration. Thus, methods have been proposed that a part of lens units (an image blur compensation lens unit) is parallel-displaced in a direction perpendicular to the optical axis in accordance with a change in the orientation of the entire lens system (e.g., Japanese Laid-Open Patent Publication No. H6-123836 (Reference 2), Japanese Patent Publication No. 3395169 (Reference 3), Japanese Laid-Open Patent Publication No. H6-130330 (Reference 4) and Japanese Laid-Open Patent Publication No. H11-202201 (Reference 5)). 
         [0007]    Each of the telephoto zoom lens systems described in References 2, 3, and 4 consists of five lens units of positive, negative, negative, positive and negative in order from the object side to the image side. The telephoto zoom lens system described in Reference 5 consists of five lens units of positive, negative, negative, positive and negative or alternatively positive, negative, positive, positive and negative in order from the object side to the image side. In each telephoto zoom lens system, one of the five lens units is parallel-displaced in a direction perpendicular to the optical axis so that image blur compensation is achieved. When the individual lens units are referred to as the first lens unit, the second lens unit, . . . , and the fifth lens unit in order from the object side to the image side, the third lens unit in the telephoto zoom lens system described in Reference 2 is parallel-displaced in a direction perpendicular to the optical axis. Similarly, the second lens unit in the telephoto zoom lens system described in Reference 3, the fourth lens unit of the telephoto zoom lens system described in Reference 4, and a part of the second lens unit of the telephoto zoom lens system described in Reference 5 are parallel-displaced in a direction perpendicular to the optical axis. 
         [0008]    In focusing in a telephoto zoom lens, a method of moving the first lens unit located on the most object side has widely been employed. Nevertheless, this focusing method based on the movement of the first lens unit causes a problem that high-speed auto-focusing cannot be achieved because of the largeness and heaviness of the first lens unit. For the purpose of resolving this problem, in the telephoto zoom lens system described in Reference 5, focusing from an infinite distance to a close distance is proposed to be achieved by moving the fourth lens unit in an optical axis direction. 
         [0009]    In interchangeable-lens type digital camera systems, video image taking is also desired in addition to still image taking. However, in video image taking, auto-focusing need be performed continuously at a high speed. 
         [0010]    In order that auto-focusing should be performed continuously at a high speed, for example, a method of repeating a series of the following operations: oscillating (wobbling) a part of lens units in the optical axis directions at a high speed so that a situation of “out-of-focus state-&gt;in-focus state-&gt;out-of-focus state” is obtained; detecting, from the output signal of the image sensor, signal components in a predetermined frequency band in a part of the image region so that an optimal position realizing the in-focus state is calculated for the focusing lens unit; and moving the focusing lens unit to the optimal position, may be adopted. In order that uneasiness such as flickers should be avoided, video displaying need be performed at a high rate of, for example, 30 frames per second. Thus, basically, image taking also need be performed at the same rate of 30 frames per second. Accordingly, in auto-focusing in video image taking, the focusing lens unit need be wobbled continuously at the high rate of 30 Hz. 
         [0011]    When the above-mentioned wobbling is to be employed, it should be noted that the size of the image corresponding to a photographic object varies in association with wobbling. This variation is caused mainly by the fact that the movement of the focusing lens unit in the optical axis directions generates a change in the focal length of the entire lens system. Then, when a large change in the image taking magnification is generated in association with wobbling, uneasiness is caused. 
         [0012]    When the above-mentioned facts are taken into consideration, in order that the outer diameter of the lens barrel should be reduced, the weight of the image blur compensation lens unit and the focusing lens unit need be reduced as light as possible. For this purpose, the outer diameters of the individual lens elements that constitute the image blur compensation lens unit and the focusing lens unit need be reduced as small as possible so that the weight of the individual lens units need be reduced as light as possible. In this view, the techniques in the above-mentioned references have problems individually. 
         [0013]    For example, References 1 to 4 do not mention image blur compensation. Further, in the zoom lens system described in Reference 5, the fourth lens unit that moves at the time of focusing is also composed of three or four lens elements. Thus, the fourth lens unit is heavy. This causes a problem that a larger motor or actuator for moving the fourth lens unit is required. 
       SUMMARY OF THE INVENTION 
       [0014]    The present invention has been devised in view of the above-mentioned problems. An object of the present invention is to provide: a zoom lens system having an image blur compensation function, satisfactory imaging characteristics, and a compact construction; and a camera system employing this zoom lens system. 
         [0015]    The zoom lens system according to the present invention, in order from an object side to an image side, comprises: a first lens unit having positive optical power; a second lens unit having negative optical power; and at least two subsequent lens units. The at least two subsequent lens units include a lens unit A and a lens unit B arranged on the image side relative to the lens unit A. At the time of zooming, all lens units move in a direction along the optical axis so that intervals between the lens units vary. At the time of focusing, the lens unit A moves in a direction along the optical axis. The lens system satisfies the following condition. 
         [0000]      0.10 &lt;|f   BAK   /f   F /( f   T   /f   W )&lt;15.0 
         [0016]    (here, f T /f W &gt;4, ω W &lt;20°) 
         [0017]    The interchangeable lens apparatus according to the present invention comprises: a zoom lens system described above; and a camera mount section connected to a camera body provided with an image sensor for receiving an optical image formed by the zoom lens system and then converting the optical image into an electric image signal. 
         [0018]    The camera system according to the present invention comprises: an interchangeable lens apparatus that includes the zoom lens system described above; and a camera body that is connected to the interchangeable lens apparatus via a camera mount section in an attachable and detachable manner and that includes an image sensor for receiving an optical image formed by the zoom lens system and then converting the optical image into an electric image signal. 
         [0019]    According to the present invention, a zoom lens system can be provided that includes a compactly constructed focusing lens unit and that has a suppressed change in the image magnification at the time of movement of a focusing lens unit; and an interchangeable lens apparatus and a camera system that employ this zoom lens system. 
         [0020]    These and other objects, features, aspects and effects of the present invention will become clearer on the basis of the following detailed description with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 1 (Example 1); 
           [0022]      FIG. 2  is a longitudinal aberration diagram showing an infinity in-focus condition of a zoom lens system according to Example 1; 
           [0023]      FIG. 3  is a longitudinal aberration diagram showing a close-point in-focus condition of a zoom lens system according to Example 1; 
           [0024]      FIG. 4  is a lateral aberration diagram in a basic state where image blur compensation is not performed and in an image blur compensation state at a telephoto limit of a zoom lens system according to Example 1; 
           [0025]      FIG. 5  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 2 (Example 2); 
           [0026]      FIG. 6  is a longitudinal aberration diagram showing an infinity in-focus condition of a zoom lens system according to Example 2; 
           [0027]      FIG. 7  is a longitudinal aberration diagram showing a close-point in-focus condition of a zoom lens system according to Example 2; 
           [0028]      FIG. 8  is a lateral aberration diagram in a basic state where image blur compensation is not performed and in an image blur compensation state at a telephoto limit of a zoom lens system according to Example 2; 
           [0029]      FIG. 9  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 3 (Example 3); 
           [0030]      FIG. 10  is a longitudinal aberration diagram showing an infinity in-focus condition of a zoom lens system according to Example 3; 
           [0031]      FIG. 11  is a longitudinal aberration diagram showing a close-point in-focus condition of a zoom lens system according to Example 3; 
           [0032]      FIG. 12  is a lateral aberration diagram in a basic state where image blur compensation is not performed and in an image blur compensation state at a telephoto limit of a zoom lens system according to Example 3; 
           [0033]      FIG. 13  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 4 (Example 4); 
           [0034]      FIG. 14  is a longitudinal aberration diagram showing an infinity in-focus condition of a zoom lens system according to Example 4; 
           [0035]      FIG. 15  is a longitudinal aberration diagram showing a close-point in-focus condition of a zoom lens system according to Example 4; 
           [0036]      FIG. 16  is a lateral aberration diagram in a basic state where image blur compensation is not performed and in an image blur compensation state at a telephoto limit of a zoom lens system according to Example 4; 
           [0037]      FIG. 17  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 5 (Example 5); 
           [0038]      FIG. 18  is a longitudinal aberration diagram showing an infinity in-focus condition of a zoom lens system according to Example 5; 
           [0039]      FIG. 19  is a longitudinal aberration diagram showing a close-point in-focus condition of a zoom lens system according to Example 5; 
           [0040]      FIG. 20  is a lateral aberration diagram in a basic state where image blur compensation is not performed and in an image blur compensation state at a telephoto limit of a zoom lens system according to Example 5; 
           [0041]      FIG. 21  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 6 (Example 6); 
           [0042]      FIG. 22  is a longitudinal aberration diagram showing an infinity in-focus condition of a zoom lens system according to Example 6; 
           [0043]      FIG. 23  is a longitudinal aberration diagram showing a close-point in-focus condition of a zoom lens system according to Example 6; 
           [0044]      FIG. 24  is a lateral aberration diagram in a basic state where image blur compensation is not performed and in an image blur compensation state at a telephoto limit of a zoom lens system according to Example 6; 
           [0045]      FIG. 25  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 7 (Example 7); 
           [0046]      FIG. 26  is a longitudinal aberration diagram showing an infinity in-focus condition of a zoom lens system according to Example 7; 
           [0047]      FIG. 27  is a longitudinal aberration diagram showing a close-point in-focus condition of a zoom lens system according to Example 7; 
           [0048]      FIG. 28  is a lateral aberration diagram in a basic state where image blur compensation is not performed and in an image blur compensation state at a telephoto limit of a zoom lens system according to Example 7; and 
           [0049]      FIG. 29  is a block diagram of a camera system according to Embodiment 8. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0050]    Each of  FIGS. 1 ,  5 ,  9 ,  13 ,  17 ,  21  and  25  shows a zoom lens system in an infinity in-focus condition. 
         [0051]    In each Fig., part (a) shows a lens configuration at a wide-angle limit (in the minimum focal length condition: focal length f W ), part (b) shows a lens configuration at a middle position (in an intermediate focal length condition: focal length f M =√{square root over ( )}(f W *f T )), and part (c) shows a lens configuration at a telephoto limit (in the maximum focal length condition: focal length f T ). Further, in each Fig., each bent arrow located between part (a) and part (b) indicates a line obtained by connecting the positions of each lens unit respectively at a wide-angle limit, a middle position and a telephoto limit. In the part between the wide-angle limit and the middle position and the part between the middle position and the telephoto limit, the positions are connected simply with a straight line, and hence this line does not indicate actual motion of each lens unit. Moreover, in each Fig., an arrow imparted to a lens unit indicates focusing from an infinity in-focus condition to a close-object in-focus condition. That is, the arrow indicates the moving direction at the time of focusing from an infinity in-focus condition to a close-object in-focus condition. 
         [0052]    Further, in  FIGS. 1 ,  5 ,  9 ,  13 ,  17 ,  21  and  25 , an asterisk “*” imparted to a particular surface indicates that the surface is aspheric. In each Fig., symbol (+) or (−) imparted to the symbol of each lens unit corresponds to the sign of the optical power of the lens unit. Further, in each Fig., the straight line located on the most right-hand side indicates the position of the image surface S. 
       Embodiment 1 
       [0053]    The zoom lens system according to Embodiment 1, in order from the object side to the image side, comprises a first lens unit G 1  having positive optical power, a second lens unit G 2  having negative optical power, a third lens unit G 3  having negative optical power, a fourth lens unit G 4  having positive optical power, a 5A-th lens unit G 5 A having negative optical power, and a 5B-th lens unit G 5 B having positive optical power. 
         [0054]    The first lens unit G 1 , in order from the object side to the image side, comprises: a negative meniscus first lens element L 1  with the convex surface facing the object side; a bi-convex second lens element L 2 ; and a positive meniscus third lens element L 3  with the convex surface facing the object side. The first lens element L 1  and the second lens element L 2  are cemented with each other. 
         [0055]    The second lens unit G 2 , in order from the object side to the image side, comprises: a negative meniscus fourth lens element L 4  with the convex surface facing the object side; and a positive meniscus fifth lens element L 5  with the convex surface facing the object side. 
         [0056]    The third lens unit G 3  comprises: a bi-concave sixth lens element L 6 ; and a positive meniscus seventh lens element L 7  with the convex surface facing the object side. 
         [0057]    The fourth lens unit G 4  comprises: a positive meniscus eighth lens element L 8  with the concave surface facing the object side; a bi-convex ninth lens element L 9 ; a negative meniscus tenth lens element L 10  with the convex surface facing the object side; a bi-convex eleventh lens element L 11 ; a bi-convex twelfth lens element L 12 ; and a negative meniscus thirteenth lens element L 13  with the concave surface facing the object side. The tenth lens element L 10  and the eleventh lens element L 11  are cemented with each other. Further, the twelfth lens element L 12  and the thirteenth lens element L 13  are cemented with each other. 
         [0058]    The 5A-th lens unit G 5 A is composed of a negative meniscus fourteenth lens element L 14  with the concave surface facing the image side. 
         [0059]    The 5B-th lens unit G 5 B comprises: a bi-convex fifteenth lens element L 15 ; and a negative meniscus sixteenth lens element L 16  with the convex surface facing the object side. 
         [0060]    At the time of zooming from a wide-angle limit to a telephoto limit, the individual lens units move in a direction along the optical axis. 
         [0061]    An aperture diaphragm A is arranged between the third lens unit G 3  and the fourth lens unit G 4 , and moves together with the third lens unit G 3 . 
         [0062]    Further, at the time of focusing from an infinity in-focus condition to a close-point in-focus condition, the 5A-th lens unit G 5 A moves to the image side along the optical axis. 
         [0063]    Further, for the purpose of compensation of image blur caused by vibration applied to the entire system, the third lens unit G 3  moves in a direction perpendicular to the optical axis. Here, the planar plate L 15  arranged on the most image side corresponds to a low-pass filter or a face plate. 
       Embodiment 2 
       [0064]    The zoom lens system according to Embodiment 2, in order from the object side to the image side, comprises a first lens unit G 1  having positive optical power, a second lens unit G 2  having negative optical power, a third lens unit G 3  having negative optical power, a fourth lens unit G 4  having positive optical power, a fifth lens unit G 5  having negative optical power, and a 5B-th lens unit G 5 B having positive optical power. 
         [0065]    The first lens unit G 1 , in order from the object side to the image side, comprises: a negative meniscus first lens element L 1  with the convex surface facing the object side; a bi-convex second lens element L 2 ; and a positive meniscus third lens element L 3  with the convex surface facing the object side. The first lens element L 1  and the second lens element L 2  are cemented with each other. 
         [0066]    The second lens unit G 2 , in order from the object side to the image side, comprises a bi-concave fourth lens element L 4  and a bi-convex fifth lens element L 5 . 
         [0067]    The third lens unit G 3  comprises: a bi-concave sixth lens element L 6 ; and a positive meniscus seventh lens element L 7  with the convex surface facing the object side. 
         [0068]    The fourth lens unit G 4  comprises: a positive meniscus eighth lens element L 8  with the concave surface facing the object side; a bi-convex ninth lens element L 9 ; a negative meniscus tenth lens element L 10  with the convex surface facing the object side; a bi-convex eleventh lens element L 11 ; and a bi-convex twelfth lens element L 12 . 
         [0069]    The 5A-th lens unit G 5 A is composed of a bi-concave thirteenth lens element L 13 . 
         [0070]    The 5B-th lens unit G 5 B is composed of a positive meniscus fourteenth lens element L 14  with the convex surface facing the object side. 
         [0071]    At the time of zooming from a wide-angle limit to a telephoto limit, the individual lens units move in a direction along the optical axis. 
         [0072]    An aperture diaphragm A is arranged between the third lens unit G 3  and the fourth lens unit G 4 , and moves together with the third lens unit G 3 . 
         [0073]    Further, at the time of focusing from an infinity in-focus condition to a close-point in-focus condition, the 5A-th lens unit G 5 A moves to the image side along the optical axis. 
         [0074]    Further, for the purpose of compensation of image blur caused by vibration applied to the entire system, the third lens unit G 3  moves in a direction perpendicular to the optical axis. 
         [0075]    Here, the planar plate L 15  arranged on the most image side corresponds to a low-pass filter or a face plate. 
       Embodiment 3 
       [0076]    The zoom lens system according to Embodiment 3, in order from the object side to the image side, comprises a first lens unit G 1  having positive optical power, a second lens unit G 2  having negative optical power, a third lens unit G 3  having negative optical power, a fourth lens unit G 4  having positive optical power, a 5A-th lens unit G 5 A having positive optical power, and a 5B-th lens unit G 5 B having negative optical power. 
         [0077]    The first lens unit G 1 , in order from the object side to the image side, comprises: a negative meniscus first lens element L 1  with the convex surface facing the object side; a positive meniscus second lens element L 2  with the convex surface facing the object side; and a positive meniscus third lens element L 3  with the convex surface facing the object side. The first lens element L 1  and the second lens element L 2  are cemented with each other. 
         [0078]    The second lens unit G 2 , in order from the object side to the image side, comprises a bi-concave fourth lens element L 4  and a bi-convex fifth lens element L 5 . 
         [0079]    The third lens unit G 3  comprises: a bi-concave sixth lens element L 6 ; and a positive meniscus seventh lens element L 7  with the convex surface facing the object side. The sixth lens element L 6  and the seventh lens element L 7  are cemented with each other. 
         [0080]    The fourth lens unit G 4  comprises: a bi-convex eighth lens element L 8 ; a bi-convex ninth lens element L 9 ; and a negative meniscus tenth lens element L 10  with the concave surface facing the object side. The ninth lens element L 9  and the tenth lens element L 10  are cemented with each other. 
         [0081]    The 5A-th lens unit G 5 A comprises: a positive meniscus eleventh lens element L 11  with the concave surface facing the object side; and a bi-convex twelfth lens element L 12 . 
         [0082]    The 5B-th lens unit G 5 B is composed of a negative meniscus thirteenth lens element L 13  with the convex surface facing the object side. 
         [0083]    At the time of zooming from a wide-angle limit to a telephoto limit, the individual lens units move in a direction along the optical axis. 
         [0084]    An aperture diaphragm A is arranged between the third lens unit G 3  and the fourth lens unit G 4 , and moves together with the third lens unit G 3 . 
         [0085]    Further, at the time of focusing from an infinity in-focus condition to a close-point in-focus condition, the 5A-th lens unit G 5 A moves to the object side along the optical axis. 
         [0086]    Further, for the purpose of compensation of image blur caused by vibration applied to the entire system, the third lens unit G 3  moves in a direction perpendicular to the optical axis. 
         [0087]    Here, the planar plate L 14  arranged on the most image side corresponds to a low-pass filter or a face plate. 
       Embodiment 4 
       [0088]    The zoom lens system according to Embodiment 4, in order from the object side to the image side, comprises a first lens unit G 1  having positive optical power, a second lens unit G 2  having negative optical power, a third lens unit G 3  having positive optical power, a fourth lens unit G 4  having positive optical power, and a fifth lens unit G 5  having negative optical power. 
         [0089]    The first lens unit G 1 , in order from the object side to the image side, comprises: a negative meniscus first lens element L 1  with the convex surface facing the object side; a positive meniscus second lens element L 2  with the convex surface facing the object side; and a positive meniscus third lens element L 3  with the convex surface facing the object side. The first lens element L 1  and the second lens element L 2  are cemented with each other. 
         [0090]    The second lens unit G 2 , in order from the object side to the image side, comprises: a bi-concave fourth lens element L 4 ; a positive meniscus fifth lens element L 5  with the convex surface facing the object side; a bi-concave sixth lens element L 6 ; and a positive meniscus seventh lens element L 7  with the convex surface facing the object side. The fourth lens element L 4  and the fifth lens element L 5  are cemented with each other. The sixth lens element L 6  and the seventh lens element L 7  are cemented with each other. 
         [0091]    The third lens unit G 3  comprises: a bi-convex eighth lens element L 8 ; a bi-convex ninth lens element L 9 ; and a negative meniscus tenth lens element L 10  with the concave surface facing the object side. The ninth lens element L 9  and the tenth lens element L 10  are cemented with each other. 
         [0092]    The fourth lens unit G 4  comprises a bi-convex eleventh lens element L 11  and a bi-convex twelfth lens element L 12 . 
         [0093]    The fifth lens unit G 5  is composed of a bi-concave thirteenth lens element L 13 . 
         [0094]    At the time of zooming from a wide-angle limit to a telephoto limit, the individual lens units move in a direction along the optical axis. 
         [0095]    An aperture diaphragm A is arranged between the second lens unit G 2  and the third lens unit G 3 , and moves together with the second lens unit G 2 . 
         [0096]    Further, at the time of focusing from an infinity in-focus condition to a close-point in-focus condition, the fourth lens unit G 4  moves to the object side along the optical axis. 
         [0097]    Further, for the purpose of compensation of image blur caused by vibration applied to the entire system, a cemented lens element constructed by cementing the sixth lens element L 6  and the seventh lens element L 7  in the second lens unit G 2  with each other moves in a direction perpendicular to the optical axis. 
         [0098]    Here, the planar plate L 14  arranged on the most image side corresponds to a low-pass filter or a face plate. 
       Embodiment 5 
       [0099]    The zoom lens system according to Embodiment 5, in order from the object side to the image side, comprises a first lens unit G 1  having positive optical power, a second lens unit G 2  having negative optical power, a third lens unit G 3  having positive optical power, a 4A-th lens unit G 4 A having negative optical power, and a 4B-th lens unit G 4 B having positive optical power. 
         [0100]    The first lens unit G 1 , in order from the object side to the image side, comprises: a negative meniscus first lens element L 1  with the convex surface facing the object side; a bi-convex second lens element L 2 ; and a positive meniscus third lens element L 3  with the convex surface facing the object side. The first lens element L 1  and the second lens element L 2  are cemented with each other. 
         [0101]    The second lens unit G 2 , in order from the object side to the image side, comprises: a negative meniscus fourth lens element L 4  with the convex surface facing the object side; a positive meniscus fifth lens element L 5  with the convex surface facing the object side; a bi-concave sixth lens element L 6 ; and a positive meniscus seventh lens element L 7  with the convex surface facing the object side. 
         [0102]    The third lens unit G 3  comprises: a positive meniscus eighth lens element L 8  with the convex surface facing the image side; a positive meniscus ninth lens element L 9  with the convex surface facing the image side; a negative meniscus tenth lens element L 10  with the convex surface facing the object side; a bi-convex eleventh lens element L 11 ; a bi-convex twelfth lens element L 12 ; and a negative meniscus thirteenth lens element L 13  with the convex surface facing the image side. The tenth lens element L 10  and the eleventh lens element L 11  are cemented with each other. Further, the twelfth lens element L 12  and the thirteenth lens element L 13  are cemented with each other. 
         [0103]    The 4A-th lens unit G 4 A is composed of a bi-concave fourteenth lens element L 14 . 
         [0104]    The 4B-th lens unit G 4 B comprises: a bi-convex fifteenth lens element L 15 ; and a sixteenth lens element L 16  with the convex surface facing the object side. 
         [0105]    At the time of zooming from a wide-angle limit to a telephoto limit, the individual lens units move in a direction along the optical axis. 
         [0106]    An aperture diaphragm A is arranged between the second lens unit G 2  and the third lens unit G 3 , and moves together with the second lens unit G 2 . 
         [0107]    Further, at the time of focusing from an infinity in-focus condition to a close-point in-focus condition, the 4A-th lens unit G 4 A moves to the image side along the optical axis. 
         [0108]    Further, for the purpose of compensation of image blur caused by vibration applied to the entire system, a cemented lens element constructed by cementing the sixth lens element L 6  and the seventh lens element L 7  in the second lens unit G 2  with each other moves in a direction perpendicular to the optical axis. 
         [0109]    Here, the planar plate L 17  arranged on the most image side corresponds to a low-pass filter or a face plate. 
       Embodiment 6 
       [0110]    The zoom lens system according to Embodiment 6, in order from the object side to the image side, comprises a first lens unit G 1  having positive optical power, a second lens unit G 2  having negative optical power, a third lens unit G 3  having positive optical power, a fourth lens unit G 4  having positive optical power, and a fifth lens unit G 5  having negative optical power. 
         [0111]    The first lens unit G 1 , in order from the object side to the image side, comprises: a negative meniscus first lens element L 1  with the convex surface facing the object side; a positive meniscus second lens element L 2  with the convex surface facing the object side; and a positive meniscus third lens element L 3  with the convex surface facing the object side. The first lens element L 1  and the second lens element L 2  are cemented with each other. 
         [0112]    The second lens unit G 2 , in order from the object side to the image side, comprises: a bi-concave fourth lens element L 4 ; a bi-convex fifth lens element L 5 ; a bi-concave sixth lens element L 6 ; and a positive meniscus seventh lens element L 7  with the convex surface facing the object side. The fourth lens element L 4  and the fifth lens element L 5  are cemented with each other. The sixth lens element L 6  and the seventh lens element L 7  are cemented with each other. 
         [0113]    The third lens unit G 3  comprises: a bi-convex eighth lens element L 8 ; a bi-convex ninth lens element L 9 ; and a negative meniscus tenth lens element L 10  with the convex surface facing the object side. The ninth lens element L 9  and the tenth lens element L 10  are cemented with each other. 
         [0114]    The 4A-th lens unit G 4 A comprises: a positive meniscus eleventh lens element L 11  with the concave surface facing the object side; a negative meniscus twelfth lens element L 12  with the convex surface facing the image side; and a bi-convex thirteenth lens element L 13 . 
         [0115]    The fifth lens unit G 5  is composed of a bi-concave fourteenth lens element L 14 . 
         [0116]    At the time of zooming from a wide-angle limit to a telephoto limit, the individual lens units move in a direction along the optical axis. 
         [0117]    An aperture diaphragm A is arranged between the second lens unit G 2  and the third lens unit G 3 , and moves together with the third lens unit G 3 . 
         [0118]    Further, at the time of focusing from an infinity in-focus condition to a close-point in-focus condition, the fourth lens unit G 4  moves to the object side along the optical axis. 
         [0119]    Further, for the purpose of compensation of image blur caused by vibration applied to the entire system, a cemented lens element constructed by cementing the sixth lens element L 6  and the seventh lens element L 7  in the second lens unit G 2  with each other moves in a direction perpendicular to the optical axis. 
         [0120]    Here, the planar plate L 15  arranged on the most image side corresponds to a low-pass filter or a face plate. 
       Embodiment 7 
       [0121]    The zoom lens system according to Embodiment 7, in order from the object side to the image side, comprises a first lens unit G 1  having positive optical power, a second lens unit G 2  having negative optical power, a third lens unit G 3  having positive optical power, a fourth lens unit G 4  having negative optical power, a 4A-th lens unit G 4 A having positive optical power, and a fifth lens unit G 5  having negative optical power. 
         [0122]    The first lens unit G 1 , in order from the object side to the image side, comprises: a negative meniscus first lens element L 1  with the convex surface facing the object side; a positive meniscus second lens element L 2  with the convex surface facing the object side; and a positive meniscus third lens element L 3  with the convex surface facing the object side. The first lens element L 1  and the second lens element L 2  are cemented with each other. 
         [0123]    The second lens unit G 2 , in order from the object side to the image side, comprises: a bi-concave fourth lens element L 4 ; a bi-convex fifth lens element L 5 ; a bi-concave sixth lens element L 6 ; and a positive meniscus seventh lens element L 7  with the convex surface facing the object side. The fourth lens element L 4  and the fifth lens element L 5  are cemented with each other. The sixth lens element L 6  and the seventh lens element L 7  are cemented with each other. 
         [0124]    The third lens unit G 3  comprises: a bi-convex eighth lens element L 8 ; a bi-convex ninth lens element L 9 ; and a negative meniscus tenth lens element L 10  with the concave surface facing the object side. The ninth lens element L 9  and the tenth lens element L 10  are cemented with each other. 
         [0125]    The fourth lens unit G 4  comprises a bi-convex eleventh lens element L 11  and a bi-concave twelfth lens element L 12 . The eleventh lens element L 11  and the twelfth lens element L 12  are cemented with each other. 
         [0126]    The 4A-th lens unit G 4 A is composed of a bi-convex thirteenth lens element L 13 . 
         [0127]    The fifth lens unit G 5  is composed of a bi-concave fourteenth lens element L 14 . 
         [0128]    At the time of zooming from a wide-angle limit to a telephoto limit, the individual lens units move in a direction along the optical axis. 
         [0129]    An aperture diaphragm A is arranged between the second lens unit G 2  and the third lens unit G 3 , and moves together with the third lens unit G 3 . 
         [0130]    Further, at the time of focusing from an infinity in-focus condition to a close-point in-focus condition, the fourth lens unit G 4  moves to the image side along the optical axis. 
         [0131]    Further, for the purpose of compensation of image blur caused by vibration applied to the entire system, a cemented lens element constructed by cementing the sixth lens element L 6  and the seventh lens element L 7  in the second lens unit G 2  with each other moves in a direction perpendicular to the optical axis. 
         [0132]    Here, the planar plate L 15  arranged on the most image side corresponds to a low-pass filter or a face plate. 
         [0133]    The following description is given for conditions to be satisfied by the zoom lens system according to each embodiment. Here, in the zoom lens system according to each embodiment, a plurality of conditions to be satisfied are set forth. Thus, a configuration of a zoom lens system that satisfies as many applicable conditions as possible is most preferable. However, when an individual condition is satisfied, a zoom lens system having the corresponding effect can be obtained. 
         [0134]    Among the zoom lens systems according to the individual embodiments, in telephoto-oriented zoom lens systems that have a configuration that the focusing lens unit is not located on the most image side, it is preferable that the following condition is satisfied. 
         [0000]      0.10&lt;| f   BAK   /f   F |/( f   T   /f   W )&lt;15.0  (1) 
         [0135]    (here, f T /f W &gt;4, ω W &lt;20°) 
         [0136]    where, 
         [0137]    f BAK  is a composite focal length of the lens units arranged on the image side relative to the focusing lens unit at a wide-angle limit, 
         [0138]    f F  is a focal length of the focusing lens unit, 
         [0139]    f T  is a focal length of the entire system at a telephoto limit, 
         [0140]    f W  is a focal length of the entire system at a wide-angle limit, and 
         [0141]    ω W  is a half view angle at a wide-angle limit. 
         [0142]    The condition (1) relates to the focal lengths of the focusing lens unit and the subsequent lens units. When the value exceeds the upper limit of the condition (1), the focal length of the lens units arranged on the image side relative to the focusing lens unit becomes shorter in comparison with that of the focusing lens unit. This causes difficulty in compensating, by the subsequent lens units, aberration fluctuation generated in association with focusing. Thus, this situation is unpreferable. In contrast, when the value goes below the lower limit of the condition (1), the focal length of the lens units arranged on the image side relative to the focusing lens unit becomes excessively great. This causes an increase in the overall length, and hence causes difficulty in realizing a compact zoom lens system. 
         [0143]    Among the zoom lens systems according to the individual embodiments, in telephoto-oriented zoom lens systems that have a configuration that the focusing lens unit is not located on the most image side, it is preferable that the following condition is satisfied. 
         [0000]      0.10&lt;| f   BAK   /f   F   |/f   W &lt;15.0  (2) 
         [0144]    (here, f T /f W &gt;4) 
         [0145]    where, 
         [0146]    f BAK  is a composite focal length of the lens units arranged on the image side relative to the focusing lens unit at a wide-angle limit, 
         [0147]    f F  is a focal length of the focusing lens unit, and 
         [0148]    f W  is a focal length of the entire system at a wide-angle limit. 
         [0149]    The condition (2) relates to the focal lengths of the focusing lens unit and the subsequent lens units. When the value exceeds the upper limit of the condition (2), the focal length of the lens units arranged on the image side relative to the focusing lens unit becomes shorter in comparison with that of the focusing lens unit. This causes difficulty in compensating, by the subsequent lens units, aberration fluctuation generated in association with focusing. Thus, this situation is unpreferable. In contrast, when the value goes below the lower limit of the condition (2), the focal length of the lens units arranged on the image side relative to the focusing lens unit becomes excessively great. This causes an increase in the overall length, and hence causes difficulty in realizing a compact zoom lens system. 
         [0150]    As in the zoom lens systems according to the individual embodiments, when the image blur compensation lens unit is located on the object side relative to the focusing lens unit, it is preferable that the following condition is satisfied. 
         [0000]      0.3&lt;| f   F   /f   of |&lt;6.0  (3) 
         [0151]    where, 
         [0152]    f F  is a focal length of the focusing lens unit, and 
         [0153]    f of  is a composite focal length of the lens units located within a range from the image blur compensation lens unit to the focusing lens unit at a wide-angle limit. 
         [0154]    The condition (3) relates to the focal lengths of the image blur compensation lens unit and the focusing lens unit. When the value exceeds the upper limit of the condition (3), the focal length of the image blur compensation lens unit becomes excessively small. This causes difficulty in compensating off-axial aberration generated in association with image blur compensation. Thus, this situation is unpreferable. In contrast, when the value goes below the lower limit of the condition (3), the focal length of the focusing lens unit becomes short. At the same time, aberration fluctuation at the time of focusing increases. This causes difficulty in compensation. 
         [0155]    As in the zoom lens systems according to the individual embodiments, when the image blur compensation lens unit is located on the object side relative to the focusing lens unit, it is preferable that the following condition is satisfied. 
         [0000]      0.5 &lt;|f   o   /f   W |&lt;2.8  (4) 
         [0156]    (here, f T /f W &gt;4) 
         [0157]    where, 
         [0158]    f o  is a focal length of the image blur compensation lens unit, 
         [0159]    f T  is a focal length of the entire system at a telephoto limit, and 
         [0160]    f W  is a focal length of the entire system at a wide-angle limit. 
         [0161]    The condition (4) sets forth the focal length of the image blur compensation lens unit. When the value exceeds the upper limit of the condition (4), the focal length of the image blur compensation lens unit becomes short. This causes difficulty in compensating, by the subsequent lens units, off-axial aberration fluctuation generated in association with image blur compensation. Thus, this situation is unpreferable. In contrast, when the value goes below the lower limit of the condition (4), the focal length of the image blur compensation lens unit becomes excessively long. Thus, the movement of lens units at the time of image blur compensation becomes large. Accordingly, this situation is unpreferable. 
         [0162]    Here, the individual lens units in each embodiment are composed exclusively of refractive type lens elements that deflect incident light by refraction (that is, lens elements of a type in which deflection is achieved at the interface between media each having a distinct refractive index). However, the present invention is not limited to this construction. For example, the lens units may employ diffractive type lens elements that deflect the incident light by diffraction; refractive-diffractive hybrid type lens elements that deflect the incident light by a combination of diffraction and refraction; or gradient index type lens elements that deflect the incident light by distribution of refractive index in the medium. 
       Embodiment 8 
       [0163]      FIG. 29  is a block diagram of a camera system according to Embodiment 8. The camera system according to Embodiment 8 includes a camera body  100  and an interchangeable lens apparatus  200 . 
         [0164]    The camera body  100  includes a camera controller  101 , an image sensor  102 , a shutter unit  103 , an image display controller  104 , an image sensor control section  105 , a contrast detection section  106 , a shutter control section  107 , an image recording control section  108 , a display  110 , a release button  111 , a memory  112 , a power supply  113  and a camera mount  114 . 
         [0165]    The camera controller  101  is an arithmetic operation unit for controlling the entire camera system. The camera controller  101  is electrically connected to the image display controller  104 , the image sensor control section  105 , the contrast detection section  106 , the shutter control section  107 , the image recording control section  108 , the memory  112  and the camera mount  114 , and can exchange signals with these sections. Further, the camera controller  101  is electrically connected to the release button  111 , and receives a signal generated at the time of operation of the release button  111 . Moreover, the camera controller  101  is connected to the power supply  113 . 
         [0166]    The image sensor  102  is composed, for example, of a CMOS sensor. The image sensor  102  converts an optical image incident on the light receiving plane into image data, and then outputs the image data. The image sensor  102  is driven in accordance with a driving signal from the image sensor control section  105 . In response to a control signal from the camera controller  101 , the image sensor control section  105  outputs a driving signal for driving the image sensor  102 , and then outputs to the camera controller  101  the image data outputted from the image sensor  102 . In response to a control signal from the camera controller  101 , the contrast detection section  106  calculates and detects the contrast of the image data outputted from the image sensor  102 , and then outputs the result to the camera controller  101 . 
         [0167]    The shutter unit  103  includes a shutter plate for shutting off the optical path for the image light to be incident on the image sensor  102 . The shutter unit  103  is driven in accordance with a driving signal from the shutter control section  107 . In response to a control signal from the camera controller  101 , the shutter control section  107  controls the opening or closing timing for the shutter plate of the shutter unit  103 . 
         [0168]    The display  110  is composed, for example, of a liquid crystal display unit. The display  110  is driven in accordance with a driving signal from the image display controller  104  so as to display an image on the display surface. In response to a control signal from the camera controller  101 , the image display controller  104  outputs image data to be displayed on the display  110  and a driving signal for driving the display  110 . 
         [0169]    In response to a control signal from the camera controller  101 , the image recording control section  108  outputs image data to a memory card  109  connected in an attachable and removable manner. 
         [0170]    The camera mount  114  mechanically connects the camera body  100  to the interchangeable lens apparatus  200  described later. Further, the camera mount  114  serves also as an interface for electrically connecting the camera body  100  to the interchangeable lens apparatus  200  described later. 
         [0171]    The interchangeable lens apparatus  200  includes a lens controller  201 , an image blur control section  202 , a diaphragm control section  203 , a focus control section  204 , a zoom control section  205 , a memory  206 , a blur detection section  207 , a diaphragm unit  208 , a zoom lens system  209  (a zoom lens unit  209   a , a focusing lens unit  209   b  and an image blur compensation lens unit  209   c ), and a lens mount  210 . 
         [0172]    The lens controller  201  is an arithmetic operation unit for controlling the entirety of the interchangeable lens apparatus  200 , and is connected through the lens mount  210  and the camera mount  114  to the camera controller  101  in the camera body described above. The lens controller  201  is electrically connected to the image blur control section  202 , the diaphragm control section  203 , the focus control section  204 , the zoom control section  205 , the memory  206  and the blur detection section  207 , and can exchange signals with these sections. 
         [0173]    The zoom lens system  209  is a zoom lens system according to Embodiment 1 described above. The zoom lens system  209  includes a zoom lens unit  209   a , a focusing lens unit  209   b , and an image blur compensation lens unit  209   c . Here, the classification of the zoom lens unit  209   a , the focusing lens unit  209   b  and the image blur compensation lens unit  209   c  is merely conceptual and adopted for simplicity of description. Thus, this classification does not exactly describe the actual construction of the actual zoom lens system. In the zoom lens system  209 , zooming is achieved when the zoom lens unit  209   a  moves in a direction along the optical axis. In the zoom lens system  209 , focusing is achieved when the focusing lens unit  209   b  moves in a direction along the optical axis. Further, in the zoom lens system  209 , image blur compensation is achieved when the image blur compensation lens unit  209   c  moves in a direction perpendicular to the optical axis. 
         [0174]    In response to a control signal from the lens controller  201 , the image blur control section  202  detects and outputs the present position of the image blur compensation lens unit  209   c . Further, the image blur control section  202  outputs a driving signal for driving the image blur compensation lens unit  209   c , so as to drive the image blur compensation lens unit  209   c  in a direction perpendicular to the optical axis. 
         [0175]    In response to a control signal from the lens controller  201 , the diaphragm control section  203  detects and outputs the present position of the diaphragm unit  208 . Further, the diaphragm control section  203  outputs a driving signal for driving the diaphragm blades provided in the diaphragm unit  208 , and thereby opens or closes the diaphragm so as to change the F-number of the optical system. 
         [0176]    In response to a control signal from the lens controller  201 , the focus control section  204  detects and outputs the present position of the focusing lens unit  209   b . Further, the focus control section  204  outputs a driving signal for driving focusing group  209   b , so as to drive the focusing lens unit  209   b  in a direction along the optical axis. 
         [0177]    In response to a control signal from the lens controller  201 , the zoom control section  205  detects and outputs the present position of the zoom lens unit  209   a . Further, the zoom control section  205  outputs a driving signal for driving the zoom lens unit  209   a , so as to drive the zoom lens unit  209   a  in a direction along the optical axis. 
         [0178]    In the above-mentioned configuration, when the release button  111  is pressed half, the camera controller  101  executes a routine of auto-focusing. First, the camera controller  101  communicates with the lens controller  201  via the camera mount  114  and the lens mount  210 , so as to detect the state of the zoom lens unit  209   a , the focusing lens unit  209   b , the image blur compensation lens unit  209   c  and the diaphragm unit  208 . 
         [0179]    Then, the camera controller  101  communicates with the lens controller  201  via the camera mount  114  and the lens mount  210 , so as to output to the lens controller  201   a  control signal for driving and wobbling the focusing lens unit  209   b . In accordance with the control signal, the lens controller  201  controls the focus control section  204  so as to drive and wobble the focusing lens unit  209   b . At the same time, the camera controller  101  communicates with the lens controller  201  via the camera mount  114  and the lens mount  210 , so as to output a control signal for instructing the lens controller  201  to adjust the aperture value into a predetermined value. In accordance with the control signal, the lens controller  201  controls the diaphragm control section  203  so as to drive the diaphragm blades of the diaphragm unit  208  in correspondence to the predetermined F-number. 
         [0180]    On the other hand, the camera controller  101  outputs a control signal to the image sensor control section  105  and the contrast detection section  106 . The image sensor control section  105  and the contrast detection section  106  individually acquire an output from the image sensor  102  in a manner corresponding to the sampling frequency of the wobbling drive of the focusing lens unit  209   b . In accordance with the control signal from the camera controller  101 , the image sensor control section  105  transmits image data corresponding to the optical image to the camera controller  101 . The camera controller  101  performs predetermined image processing onto the image data, and then transmits the result to the image display controller  104 . The image display controller  104  displays the image data in the form of a visible image onto the display  110 . 
         [0181]    Further, the contrast detection section  106  calculates the contrast value of the image data in association with wobbling, and then transmits the result to the camera controller  101 . On the basis of the detection result from the contrast detection section  106 , the camera controller  101  determines the direction of focusing movement and the amount of movement for the focusing lens unit, and then transmits the information thereof to the lens controller  201 . The lens controller  201  outputs a control signal to the focus control section  204  so as to move the focusing lens unit  209   b . In accordance with the control signal from the lens controller  201 , the focus control section  204  drives the focusing lens unit  209   b.    
         [0182]    When auto-focusing is to be performed in a live view state, the above-mentioned operation is repeated. When auto-focusing is to be performed in a live view state, wobbling of the focusing lens unit  209   b  is performed continuously. At that time, the zoom lens system according to each embodiment has merely a small image magnification change in association with wobbling, and has a light weight. Thus, an imaging lens system suitable for the above-mentioned system is obtained. 
         [0183]    Embodiment 8 given above has been described for a case that the zoom lens system according to Embodiment 1 is employed. However, obviously, a zoom lens system according to another embodiment may be employed. 
       EXAMPLES 
       [0184]    Numerical examples are described below in which the zoom lens systems according to Embodiments 1 to 7 are implemented. As described later, Numerical Examples 1 to 7 correspond to Embodiments 1 to 7, respectively. In the numerical examples, the units of the length in the tables are all “mm”, while the units of the view angle are all “°”. Moreover, in the numerical examples, r is the radius of curvature, d is the axial distance, nd is the refractive index to the d-line, and vd is the Abbe number to the d-line. In the numerical examples, the surfaces marked with “*” are aspheric surfaces, and the aspheric surface configuration is defined by the following expression. 
         [0000]    
       
         
           
             Z 
             = 
             
               
                 
                   
                     h 
                     2 
                   
                   / 
                   r 
                 
                 
                   1 
                   + 
                   
                     
                       1 
                       - 
                       
                         
                           ( 
                           
                             1 
                             + 
                             κ 
                           
                           ) 
                         
                          
                         
                           
                             ( 
                             
                               h 
                               / 
                               r 
                             
                             ) 
                           
                           2 
                         
                       
                     
                   
                 
               
               + 
               
                 ∑ 
                 
                   
                     A 
                     n 
                   
                    
                   
                     h 
                     n 
                   
                 
               
             
           
         
       
     
         [0185]    Here, the symbols in the formula indicate the following quantities. 
         [0186]    Z is the distance from an on-the-aspheric-surface point at a height h relative to the optical axis to a tangential plane at the top of the aspheric surface, 
         [0187]    h is the height relative to the optical axis, 
         [0188]    r is the radius of curvature at the top, 
         [0189]    κ is the conic constant, and 
         [0190]    An is the n-th order aspherical coefficient. 
         [0191]      FIGS. 2 ,  6 ,  10 ,  14 ,  18 ,  22  and  26  are longitudinal aberration diagrams of an infinity in-focus condition of the zoom lens systems according to Numerical Examples 1, 2, 3, 4, 5, 6 and 7. 
         [0192]      FIGS. 3 ,  7 ,  11 ,  15 ,  19 ,  23  and  27  are longitudinal aberration diagrams of a close-point in-focus condition of the zoom lens systems according to Numerical Examples 1, 2, 3, 4, 5, 6 and 7. 
         [0193]    In each longitudinal aberration diagram, part (a) shows the aberration at a wide-angle limit, part (b) shows the aberration at a middle position, and part (c) shows the aberration at a telephoto limit. Each longitudinal aberration diagram, in order from the left-hand side, shows the spherical aberration (SA (mm)), the astigmatism (AST (mm)) and the distortion (DIS (%)). In each spherical aberration diagram, the vertical axis indicates the F-number (in each Fig., indicated as F), and the solid line, the short dash line and the long dash line indicate the characteristics to the d-line, the F-line and the C-line, respectively. In each astigmatism diagram, the vertical axis indicates the image height (in each Fig., indicated as H), and the solid line and the dash line indicate the characteristics to the sagittal image plane (in each Fig., indicated as “s”) and the meridional image plane (in each Fig., indicated as “m”), respectively. In each distortion diagram, the vertical axis indicates the image height (in each Fig., indicated as H). 
         [0194]    In each numerical example, as seen from the longitudinal aberration diagram of an infinity in-focus condition and the longitudinal aberration diagram of a close-point in-focus condition, also in a close-point in-focus condition, each zoom lens system achieves satisfactory aberration performance similar to that in an infinity in-focus condition. 
         [0195]      FIGS. 4 ,  8 ,  12 ,  16 ,  20 ,  24  and  28  are lateral aberration diagrams in a basic state where image blur compensation is not performed and in an image blur compensation state of a zoom lens system according to Numerical Examples 1, 2, 3, 4, 5, 6 and 7. 
         [0196]    In each lateral aberration diagram, the aberration diagrams in the upper three parts correspond to a basic state where image blur compensation is not performed at a telephoto limit, while the aberration diagrams in the lower three parts correspond to an image blur compensation state where the image blur compensation lens unit moves by a predetermined amount in a direction perpendicular to the optical axis at a telephoto limit. Among the lateral aberration diagrams of a basic state, the upper part shows the lateral aberration at an image point of 75% of the maximum image height, the middle part shows the lateral aberration at the axial image point, and the lower part shows the lateral aberration at an image point of −75% of the maximum image height. Among the lateral aberration diagrams of an image blur compensation state, the upper part shows the lateral aberration at an image point of 75% of the maximum image height, the middle part shows the lateral aberration at the axial image point, and the lower part shows the lateral aberration at an image point of −75% of the maximum image height. In each lateral aberration diagram, the horizontal axis indicates the distance from the principal ray on the pupil surface, and the solid line, the short dash line and the long dash line indicate the characteristics to the d-line, the F-line and the C-line, respectively. In each lateral aberration diagram, the meridional image plane is adopted as the plane containing the optical axis of the first lens unit G 1 . 
         [0197]    Here, in the zoom lens system according to each numerical example, the amount (Y T ) of movement of the compensation lens unit in a direction perpendicular to the optical axis in an image blur compensation state at a telephoto limit is as follows. 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 (amount of movement of compensation lens unit) 
               
             
          
           
               
                   
                 Numerical Example 
                 Y T   
               
               
                   
                   
               
               
                   
                 1 
                 0.43 
               
               
                   
                 2 
                 0.43 
               
               
                   
                 3 
                 0.45 
               
               
                   
                 4 
                 0.31 
               
               
                   
                 5 
                 0.45 
               
               
                   
                 6 
                 0.53 
               
               
                   
                 7 
                 0.56 
               
               
                   
                   
               
             
          
         
       
     
         [0198]    As seen from the lateral aberration diagrams, in each zoom lens system, satisfactory symmetry is obtained in the lateral aberration at the axial image point. Further, when the lateral aberration at the +75% image point and the lateral aberration at the −75% image point are compared with each other in a basic state, all have a small degree of curvature and almost the same inclination in the aberration curve. Thus, decentering coma aberration and decentering astigmatism are small. This indicates that satisfactory imaging performance is obtained even in an image blur compensation state. Further, when the image blur compensation angle of a zoom lens system is the same, the amount of parallel translation required for image blur compensation decreases with decreasing focal length of the entire zoom lens system. Thus, at arbitrary zoom positions, satisfactory image blur compensation can be performed without degrading the imaging characteristics. 
       Numerical Example 1 
       [0199]    The zoom lens system of Numerical Example 1 corresponds to Embodiment 1 shown in  FIG. 1 . The data of the zoom lens system according to Numerical Example 1 is shown in the following tables. 
         [0000]    
       
         
               
             
               
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 (surface data) 
               
             
          
           
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                 Variable 
                   
                   
               
               
                  1 
                 79.88860 
                 1.20000 
                 1.84666 
                 23.8 
               
               
                  2 
                 55.84100 
                 4.38040 
                 1.49700 
                 81.6 
               
               
                  3 
                 −538.09420 
                 0.20000 
               
               
                  4 
                 40.97500 
                 4.17440 
                 1.48749 
                 70.4 
               
               
                  5 
                 171.38530 
                 Variable 
               
               
                  6 
                 149.25700 
                 0.80000 
                 1.83400 
                 37.3 
               
               
                  7 
                 19.24660 
                 4.98360 
               
               
                  8 
                 31.30520 
                 2.43820 
                 1.84666 
                 23.8 
               
               
                  9 
                 795.70900 
                 Variable 
               
               
                 10 
                 −46.11980 
                 0.79940 
                 1.77250 
                 49.6 
               
               
                 11 
                 37.65760 
                 0.68440 
               
               
                 12 
                 22.26400 
                 1.39710 
                 1.92286 
                 20.9 
               
               
                 13 
                 26.59940 
                 8.97180 
               
               
                 14 (Aperture) 
                 ∞ 
                 Variable 
               
               
                 15 
                 −85.03340 
                 1.80330 
                 1.49700 
                 81.6 
               
               
                 16 
                 −35.73500 
                 0.10050 
               
               
                 17 
                 165.76270 
                 2.00390 
                 1.49700 
                 81.6 
               
               
                 18 
                 −69.04310 
                 0.20000 
               
               
                 19 
                 54.65300 
                 0.80000 
                 1.92286 
                 20.9 
               
               
                 20 
                 37.32040 
                 2.79140 
                 1.49700 
                 81.6 
               
               
                 21 
                 −93.02670 
                 0.20000 
               
               
                 22 
                 33.57310 
                 3.54500 
                 1.49700 
                 81.6 
               
               
                 23 
                 −37.21710 
                 0.80220 
                 1.88300 
                 40.8 
               
               
                 24 
                 −94.83610 
                 Variable 
               
               
                 25 
                 3674.43700 
                 0.70110 
                 1.77250 
                 49.6 
               
               
                 26 
                 23.16340 
                 Variable 
               
               
                 27 
                 54.32140 
                 2.27740 
                 1.75520 
                 27.5 
               
               
                 28 
                 −46.59960 
                 0.10000 
               
               
                 29 
                 153.18810 
                 0.80000 
                 1.83481 
                 42.7 
               
               
                 30 
                 25.42440 
                 Variable 
               
               
                 31 
                 ∞ 
                 4.20000 
                 1.51680 
                 64.2 
               
               
                 32 
                 ∞ 
                 BF 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 3-1 
               
             
             
               
                   
               
               
                 (various data) 
               
               
                 Zooming ratio 4.24425 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                   
                 Focal length 
                 41.2718 
                 89.3913 
                 193.4154 
               
               
                   
                 F number 
                 3.59391 
                 4.65880 
                 6.26304 
               
               
                   
                 View angle 
                 15.0327 
                 6.8445 
                 3.1916 
               
               
                   
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                   
                 Overall length of 
                 116.3210 
                 129.8654 
                 154.5799 
               
               
                   
                 lens system 
               
               
                   
                 BF 
                 0.99156 
                 1.01132 
                 0.99975 
               
               
                   
                 d0 
                 ∞ 
                 ∞ 
                 ∞ 
               
               
                   
                 d5 
                 1.6530 
                 22.7100 
                 32.4306 
               
               
                   
                 d9 
                 8.5027 
                 3.4756 
                 5.9904 
               
               
                   
                 d14 
                 16.9073 
                 8.9078 
                 1.1313 
               
               
                   
                 d24 
                 15.3069 
                 10.4853 
                 1.0412 
               
               
                   
                 d26 
                 2.7426 
                 3.3486 
                 12.6422 
               
               
                   
                 d30 
                 19.8628 
                 29.5727 
                 49.9904 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 3-2 
               
             
             
               
                   
               
               
                 (various data) 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                 Focal length 
                 40.8785 
                 86.3288 
                 175.1678 
               
               
                 F number 
                 3.59488 
                 4.66053 
                 6.38448 
               
               
                 View angle 
                 15.0591 
                 6.8432 
                 3.1309 
               
               
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                 Overall length of 
                 116.3339 
                 129.8760 
                 154.4691 
               
               
                 lens system 
               
               
                 BF 
                 1.01382 
                 1.02127 
                 0.89152 
               
               
                 d0 
                 3883.6791 
                 3870.1455 
                 3845.4204 
               
               
                 d5 
                 1.6530 
                 22.7100 
                 32.4306 
               
               
                 d9 
                 8.5027 
                 3.4756 
                 5.9904 
               
               
                 d14 
                 16.9073 
                 8.9078 
                 1.1313 
               
               
                 d24 
                 15.4706 
                 11.0079 
                 2.1911 
               
               
                 d26 
                 2.5696 
                 2.8266 
                 11.4897 
               
               
                 d30 
                 19.8628 
                 29.5727 
                 49.9904 
               
               
                   
               
             
          
         
       
     
       Numerical Example 2 
       [0200]    The zoom lens system of Numerical Example 2 corresponds to Embodiment 2 shown in  FIG. 5 . The data of the zoom lens system according to Numerical Example 2 is shown in the following tables. 
         [0000]    
       
         
               
             
               
               
               
               
               
             
           
               
                 TABLE 4 
               
             
             
               
                   
               
               
                 (surface data) 
               
             
          
           
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                 Variable 
                   
                   
               
               
                  1 
                 96.08820 
                 1.20030 
                 1.84666 
                 23.8 
               
               
                  2 
                 61.13150 
                 4.96580 
                 1.49700 
                 81.6 
               
               
                  3 
                 −233.55870 
                 0.20000 
               
               
                  4 
                 47.75020 
                 3.83530 
                 1.48749 
                 70.4 
               
               
                  5 
                 206.95980 
                 Variable 
               
               
                  6 
                 −107.60720 
                 0.89610 
                 1.88300 
                 40.8 
               
               
                  7 
                 21.03400 
                 0.25840 
               
               
                  8 
                 24.92220 
                 2.49620 
                 1.78470 
                 26.1 
               
               
                  9 
                 −228.53650 
                 Variable 
               
               
                 10 
                 −37.42360 
                 0.90270 
                 1.83481 
                 42.7 
               
               
                 11 
                 27.11510 
                 0.10000 
               
               
                 12 
                 24.16450 
                 1.63050 
                 1.92286 
                 20.9 
               
               
                 13 
                 55.10970 
                 7.17610 
               
               
                 14 (Aperture) 
                 ∞ 
                 Variable 
               
               
                 15 
                 −198.76890 
                 2.19660 
                 1.49700 
                 81.6 
               
               
                 16 
                 −33.20810 
                 0.18370 
               
               
                 17 
                 60.33330 
                 2.29510 
                 1.49700 
                 81.6 
               
               
                 18 
                 −114.41090 
                 0.15780 
               
               
                 19 
                 170.03360 
                 0.89890 
                 1.84666 
                 23.8 
               
               
                 20 
                 28.36260 
                 0.20320 
               
               
                 21 
                 29.80500 
                 3.66370 
                 1.49700 
                 81.6 
               
               
                 22 
                 −61.71440 
                 0.19890 
               
               
                 23 
                 32.38510 
                 2.88520 
                 1.58921 
                 41.0 
               
               
                 24 
                 −215.78670 
                 Variable 
               
               
                 25* 
                 −696.90530 
                 0.95800 
                 1.69100 
                 54.7 
               
               
                 26* 
                 18.48420 
                 Variable 
               
               
                 27 
                 25.42090 
                 1.63640 
                 1.84666 
                 23.8 
               
               
                 28 
                 41.70670 
                 Variable 
               
               
                 29 
                 ∞ 
                 4.20000 
                 1.51680 
                 64.2 
               
               
                 30 
                 ∞ 
                 BF 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
             
           
               
                 TABLE 5 
               
             
             
               
                   
               
               
                 (aspherical data) 
               
             
          
           
               
                 Surface No. 
                 Parameters 
               
               
                   
               
               
                 25 
                 K = 0.00000E+00, A4 = −1.34852E−05, A6 = 
               
               
                   
                 4.68839E−07, A8 = −4.71690E−09, A10 = 
               
               
                   
                 1.38874E−11 
               
               
                 26 
                 K = 0.00000E+00, A4 = −2.58833E−05, A6 = 
               
               
                   
                 5.06789E−07, A8 = −4.85574E−09, A10 = 
               
               
                   
                 7.62677E−12 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 6-1 
               
             
             
               
                   
               
               
                 (various data) 
               
               
                 Zooming ratio 4.19912 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                   
                 Focal length 
                 41.5596 
                 88.1623 
                 182.1306 
               
               
                   
                 F number 
                 3.70547 
                 4.32493 
                 5.80463 
               
               
                   
                 View angle 
                 15.5868 
                 7.0732 
                 3.4237 
               
               
                   
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                   
                 Overall length of 
                 111.2799 
                 131.2672 
                 153.1675 
               
               
                   
                 lens system 
               
               
                   
                 BF 
                 1.02055 
                 1.02107 
                 1.02173 
               
               
                   
                 d0 
                 ∞ 
                 ∞ 
                 ∞ 
               
               
                   
                 d5 
                 1.4200 
                 27.8703 
                 40.9047 
               
               
                   
                 d9 
                 14.2808 
                 5.0996 
                 1.7207 
               
               
                   
                 d14 
                 9.1160 
                 7.3403 
                 1.4733 
               
               
                   
                 d24 
                 20.8421 
                 12.4878 
                 1.9989 
               
               
                   
                 d26 
                 1.5346 
                 1.0433 
                 1.8495 
               
               
                   
                 d28 
                 19.9269 
                 33.2659 
                 61.0598 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 6-2 
               
             
             
               
                   
               
               
                 (various data) 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                 Focal length 
                 41.1818 
                 87.7556 
                 174.5136 
               
               
                 F number 
                 3.70197 
                 4.45073 
                 6.19004 
               
               
                 View angle 
                 15.5982 
                 6.8813 
                 3.2215 
               
               
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                 Overall length of 
                 111.2848 
                 132.6071 
                 156.5461 
               
               
                 lens system 
               
               
                 BF 
                 1.02549 
                 3.87898 
                 5.91833 
               
               
                 d0 
                 4000.0000 
                 4000.0000 
                 4000.0000 
               
               
                 d5 
                 1.4200 
                 27.8703 
                 40.9047 
               
               
                 d9 
                 14.2808 
                 4.8789 
                 1.5000 
               
               
                 d14 
                 9.1160 
                 7.3403 
                 1.4733 
               
               
                 d24 
                 21.0270 
                 12.4890 
                 2.6288 
               
               
                 d26 
                 1.3497 
                 0.5243 
                 0.7018 
               
               
                 d28 
                 19.9269 
                 32.4864 
                 60.2803 
               
               
                   
               
             
          
         
       
     
       Numerical Example 3 
       [0201]    The zoom lens system of Numerical Example 3 corresponds to Embodiment 3 shown in  FIG. 9 . The data of the zoom lens system according to Numerical Example 3 is shown in the following tables. 
         [0000]    
       
         
               
             
               
               
               
               
               
             
           
               
                 TABLE 7 
               
             
             
               
                   
               
               
                 (surface data) 
               
             
          
           
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                 Variable 
                   
                   
               
               
                  1 
                 78.42590 
                 1.19980 
                 1.87800 
                 38.2 
               
               
                  2 
                 46.72820 
                 6.00690 
                 1.49700 
                 81.6 
               
               
                  3 
                 350.38430 
                 0.19360 
               
               
                  4 
                 48.17050 
                 5.84260 
                 1.49700 
                 81.4 
               
               
                  5 
                 1457.09620 
                 Variable 
               
               
                  6 
                 −201.19250 
                 1.00000 
                 1.75670 
                 36.3 
               
               
                  7 
                 30.51420 
                 9.30230 
               
               
                  8 
                 42.78680 
                 2.10060 
                 1.82027 
                 29.7 
               
               
                  9 
                 −1708.73110 
                 Variable 
               
               
                 10 
                 −45.94270 
                 0.79990 
                 1.75500 
                 52.3 
               
               
                 11 
                 13.13030 
                 2.22310 
                 1.84666 
                 23.9 
               
               
                 12 
                 37.49120 
                 2.00070 
               
               
                 13 (Aperture) 
                 ∞ 
                 Variable 
               
               
                 14 
                 258.91190 
                 2.09420 
                 1.59380 
                 61.4 
               
               
                 15 
                 −31.30260 
                 0.19920 
               
               
                 16 
                 269.94740 
                 4.08650 
                 1.52540 
                 70.5 
               
               
                 17 
                 −18.77030 
                 0.79960 
                 1.83918 
                 23.9 
               
               
                 18 
                 −167.79930 
                 Variable 
               
               
                 19 
                 −366.58870 
                 3.09910 
                 1.49700 
                 81.6 
               
               
                 20 
                 −32.55030 
                 0.20020 
               
               
                 21 
                 48.78510 
                 2.47730 
                 1.71852 
                 33.5 
               
               
                 22 
                 −551.02540 
                 Variable 
               
               
                 23 
                 123.85260 
                 0.77430 
                 1.71371 
                 54.5 
               
               
                 24 
                 27.80440 
                 Variable 
               
               
                 25 
                 ∞ 
                 4.19990 
                 1.51680 
                 64.2 
               
               
                 26 
                 ∞ 
                 1.20462 
               
               
                 Image surface 
                 ∞ 
                 0.00000 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 8-1 
               
             
             
               
                   
               
               
                 (various data) 
               
               
                 Zooming ratio 4.700 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                   
                 Focal length 
                 41.3304 
                 89.7286 
                 194.5268 
               
               
                   
                 F number 
                 3.71919 
                 5.10373 
                 5.99992 
               
               
                   
                 View angle 
                 15.7997 
                 6.9927 
                 3.1902 
               
               
                   
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                   
                 Overall length of 
                 135.1359 
                 152.7756 
                 171.2381 
               
               
                   
                 lens system 
               
               
                   
                 BF 
                 1.20462 
                 1.24030 
                 1.30620 
               
               
                   
                 d0 
                 ∞ 
                 ∞ 
                 ∞ 
               
               
                   
                 d5 
                 2.4969 
                 30.6249 
                 41.5125 
               
               
                   
                 d9 
                 17.1808 
                 2.6465 
                 13.0905 
               
               
                   
                 d13 
                 14.3097 
                 9.7475 
                 1.4834 
               
               
                   
                 d18 
                 9.5266 
                 9.5266 
                 9.5266 
               
               
                   
                 d22 
                 24.0081 
                 14.2184 
                 2.0000 
               
               
                   
                 d24 
                 17.8096 
                 36.1716 
                 53.7187 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 8-2 
               
             
             
               
                   
               
               
                 (various data) 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                 Focal length 
                 41.1585 
                 88.0536 
                 178.8076 
               
               
                 F number 
                 3.72518 
                 5.13555 
                 6.16865 
               
               
                 View angle 
                 15.7691 
                 6.9514 
                 3.1059 
               
               
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                 Overall length of 
                 135.1538 
                 152.7643 
                 171.3291 
               
               
                 lens system 
               
               
                 BF 
                 1.22216 
                 1.22902 
                 1.39756 
               
               
                 d0 
                 4000.0000 
                 4000.0000 
                 4000.0000 
               
               
                 d5 
                 2.4969 
                 30.6249 
                 41.5125 
               
               
                 d9 
                 17.1808 
                 2.6465 
                 13.0905 
               
               
                 d13 
                 14.3097 
                 9.7475 
                 1.4834 
               
               
                 d18 
                 9.3169 
                 8.8948 
                 7.5627 
               
               
                 d22 
                 24.2179 
                 14.8502 
                 3.9640 
               
               
                 d24 
                 17.8096 
                 36.1716 
                 53.7186 
               
               
                   
               
             
          
         
       
     
       Numerical Example 4 
       [0202]    The zoom lens system of Numerical Example 4 corresponds to Embodiment 4 shown in  FIG. 13 . The data of the zoom lens system according to Numerical Example 4 is shown in the following tables. 
         [0000]    
       
         
               
             
               
               
               
               
               
             
           
               
                 TABLE 9 
               
             
             
               
                   
               
               
                 (surface data) 
               
             
          
           
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                 ∞ 
                   
                   
               
               
                  1 
                 79.59080 
                 1.50000 
                 1.87800 
                 38.2 
               
               
                  2 
                 46.59430 
                 5.45970 
                 1.49700 
                 81.6 
               
               
                  3 
                 155.01950 
                 0.19360 
               
               
                  4 
                 43.44630 
                 6.11360 
                 1.49700 
                 81.6 
               
               
                  5 
                 211.45010 
                 Variable 
               
               
                  6 
                 −64.05960 
                 0.90000 
                 1.75670 
                 36.3 
               
               
                  7 
                 22.89500 
                 2.89770 
                 1.82114 
                 24.1 
               
               
                  8 
                 249.92920 
                 1.00000 
               
               
                  9 
                 −340.83290 
                 1.13370 
                 1.75670 
                 36.3 
               
               
                 10 
                 25.32540 
                 2.10770 
                 1.84666 
                 23.8 
               
               
                 11 
                 68.82910 
                 Variable 
               
               
                 12 (Aperture) 
                 ∞ 
                 1.40000 
               
               
                 13 
                 2150.07340 
                 1.44350 
                 1.59380 
                 61.4 
               
               
                 14 
                 −69.29450 
                 0.10100 
               
               
                 15 
                 48.20190 
                 2.29980 
                 1.52540 
                 70.5 
               
               
                 16 
                 −30.63980 
                 0.75000 
                 1.83918 
                 23.9 
               
               
                 17 
                 −94.66950 
                 Variable 
               
               
                 18 
                 234.43110 
                 1.57580 
                 1.49700 
                 81.6 
               
               
                 19 
                 −113.37950 
                 10.20840  
               
               
                 20 
                 117.93500 
                 1.74200 
                 1.71852 
                 33.5 
               
               
                 21 
                 −186.97620 
                 Variable 
               
               
                 22 
                 −49.72050 
                 0.77430 
                 1.49700 
                 81.4 
               
               
                 23 
                 35.46500 
                 Variable 
               
               
                 24 
                 ∞ 
                 4.19990 
                 1.51680 
                 64.2 
               
               
                 25 
                 ∞ 
                 0.96800 
               
               
                 26 
                 ∞ 
                 0.00000 
               
               
                 27 
                 ∞ 
                 0.05779 
               
               
                 Image surface 
                 ∞ 
                 0.00000 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 10-1 
               
             
             
               
                   
               
               
                 (various data) 
               
               
                 Zooming ratio 4.70100 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                   
                 Focal length 
                 41.2110 
                 89.3336 
                 193.7326 
               
               
                   
                 F number 
                 3.73123 
                 4.26565 
                 7.17771 
               
               
                   
                 View angle 
                 16.2431 
                 7.0701 
                 3.2335 
               
               
                   
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                   
                 Overall length of 
                 118.8851 
                 135.5682 
                 162.6738 
               
               
                   
                 lens system 
               
               
                   
                 BF 
                 0.05779 
                 0.15305 
                 −0.10748 
               
               
                   
                 d0 
                 ∞ 
                 ∞ 
                 ∞ 
               
               
                   
                 d5 
                 4.0000 
                 37.0408 
                 46.5472 
               
               
                   
                 d11 
                 29.1704 
                 12.4000 
                 1.4999 
               
               
                   
                 d17 
                 9.5265 
                 9.5266 
                 9.5269 
               
               
                   
                 d21 
                 26.3617 
                 17.1321 
                 1.6000 
               
               
                   
                 d23 
                 3.0000 
                 12.5469 
                 56.8386 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 10-2 
               
             
             
               
                   
               
               
                 (various data) 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                 Focal length 
                 40.9238 
                 85.8540 
                 175.9349 
               
               
                 F number 
                 3.75311 
                 4.29688 
                 7.26520 
               
               
                 View angle 
                 16.1200 
                 7.0087 
                 3.1923 
               
               
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                 Overall length of 
                 118.9674 
                 135.6579 
                 163.0442 
               
               
                 lens system 
               
               
                 BF 
                 0.24003 
                 0.24277 
                 0.26307 
               
               
                 d0 
                 4000.0000 
                 4000.0000 
                 4000.0000 
               
               
                 d5 
                 4.0000 
                 37.0408 
                 46.5472 
               
               
                 d11 
                 29.1704 
                 12.4000 
                 1.4999 
               
               
                 d17 
                 9.1980 
                 8.3391 
                 7.6216 
               
               
                 d21 
                 26.5903 
                 18.3196 
                 3.5051 
               
               
                 d23 
                 3.0000 
                 12.5469 
                 56.8386 
               
               
                   
               
             
          
         
       
     
       Numerical Example 5 
       [0203]    The zoom lens system of Numerical Example 5 corresponds to Embodiment 5 shown in  FIG. 17 . The data of the zoom lens system according to Numerical Example 5 is shown in the following tables. 
         [0000]    
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 11 
               
             
             
               
                   
               
               
                 (surface data) 
               
             
          
           
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
             
          
           
               
                 Object surface 
                 ∞ 
                 Variable 
                   
                   
               
               
                  1 
                 101.86910 
                 1.29990 
                 1.84666 
                 23.8 
               
               
                  2 
                 66.30390 
                 5.97060 
                 1.49700 
                 81.6 
               
               
                  3 
                 −228.10900 
                 0.10000 
               
               
                  4 
                 35.31660 
                 5.13250 
                 1.48749 
                 70.4 
               
               
                  5 
                 86.31380 
                 Variable 
               
               
                  6 
                 87.50050 
                 0.72560 
                 1.83400 
                 37.3 
               
               
                  7 
                 18.84310 
                 3.61870 
               
               
                  8 
                 25.42790 
                 2.31830 
                 1.84666 
                 23.8 
               
               
                  9 
                 79.88120 
                 10.33950  
               
               
                 10 
                 −43.20810 
                 0.70000 
                 1.68966 
                 53.0 
               
               
                 11 
                 31.99480 
                 0.10000 
               
               
                 12 
                 21.48710 
                 1.67870 
                 1.84666 
                 23.8 
               
               
                 13 
                 26.79970 
                 6.04420 
               
               
                 14 (Aperture) 
                 ∞ 
                 Variable 
               
               
                 15 
                 −894.97490 
                 1.95800 
                 1.49700 
                 81.6 
               
               
                 16 
                 −46.15270 
                 0.10000 
               
               
                 17 
                 −1236.84750 
                 1.71990 
                 1.49700 
                 81.6 
               
               
                 18 
                 −64.62930 
                 0.10000 
               
               
                 19 
                 57.92080 
                 0.70000 
                 1.92286 
                 20.9 
               
               
                 20 
                 40.65290 
                 2.72120 
                 1.49700 
                 81.6 
               
               
                 21 
                 −69.36640 
                 0.10000 
               
               
                 22 
                 32.56890 
                 3.31170 
                 1.49700 
                 81.6 
               
               
                 23 
                 −39.36570 
                 0.70000 
                 1.88300 
                 40.8 
               
               
                 24 
                 −108.41110 
                 Variable 
               
               
                 25 
                 −70.52180 
                 0.70000 
                 1.80420 
                 46.5 
               
               
                 26 
                 35.99030 
                 Variable 
               
               
                 27 
                 64.19020 
                 2.38010 
                 1.75520 
                 27.5 
               
               
                 28 
                 −42.09660 
                 0.16700 
               
               
                 29 
                 42.28970 
                 0.92740 
                 1.83481 
                 42.7 
               
               
                 30 
                 18.48540 
                 Variable 
               
               
                 31 
                 ∞ 
                 4.20000 
                 1.51680 
                 64.2 
               
               
                 32 
                 ∞ 
                 1.01774 
               
               
                 Image surface 
                 ∞ 
                 0.00000 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 12-1 
               
             
             
               
                   
               
               
                 (various data) 
               
               
                 Zooming ratio 4.174 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                   
                 Focal length 
                 46.2021 
                 93.1218 
                 192.8345 
               
               
                   
                 F number 
                 3.96589 
                 3.41298 
                 5.83505 
               
               
                   
                 View angle 
                 13.4051 
                 6.5844 
                 3.1782 
               
               
                   
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                   
                 Overall length of 
                 118.3633 
                 136.6181 
                 154.8564 
               
               
                   
                 lens system 
               
               
                   
                 BF 
                 1.01774 
                 1.05534 
                 0.98741 
               
               
                   
                 d0 
                 ∞ 
                 ∞ 
                 ∞ 
               
               
                   
                 d5 
                 1.2000 
                 26.5739 
                 30.8067 
               
               
                   
                 d14 
                 17.8126 
                 16.0634 
                 1.5284 
               
               
                   
                 d24 
                 14.6195 
                 9.7262 
                 2.0014 
               
               
                   
                 d26 
                 2.7154 
                 6.5150 
                 14.0847 
               
               
                   
                 d30 
                 23.1848 
                 18.8710 
                 47.6345 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 12-2 
               
             
             
               
                   
               
               
                 (various data) 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                 Focal length 
                 45.7045 
                 89.2199 
                 175.2455 
               
               
                 F number 
                 3.97342 
                 3.42649 
                 5.92175 
               
               
                 View angle 
                 13.4334 
                 6.6355 
                 3.1114 
               
               
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                 Overall length of 
                 118.3706 
                 136.6451 
                 154.7802 
               
               
                 lens system 
               
               
                 BF 
                 1.00732 
                 1.08544 
                 0.90846 
               
               
                 d0 
                 3884.0557 
                 3864.6948 
                 3845.7762 
               
               
                 d5 
                 1.2000 
                 26.5739 
                 30.8067 
               
               
                 d14 
                 17.8126 
                 16.0634 
                 1.5284 
               
               
                 d24 
                 14.8046 
                 10.4834 
                 3.2462 
               
               
                 d26 
                 2.5480 
                 5.7547 
                 12.8426 
               
               
                 d30 
                 23.1848 
                 18.8710 
                 47.6345 
               
               
                   
               
             
          
         
       
     
       Numerical Example 6 
       [0204]    The zoom lens system of Numerical Example 6 corresponds to Embodiment 6 shown in  FIG. 21 . The data of the zoom lens system according to Numerical Example 6 is shown in the following tables. 
         [0000]    
       
         
               
             
               
               
               
               
               
             
           
               
                 TABLE 13 
               
             
             
               
                   
               
               
                 (surface data) 
               
             
          
           
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                 Variable 
                   
                   
               
               
                  1 
                 105.76950 
                 1.50000 
                 1.87800 
                 38.2 
               
               
                  2 
                 53.77680 
                 6.66460 
                 1.49700 
                 81.6 
               
               
                  3 
                 340.13350 
                 0.19360 
               
               
                  4 
                 46.97100 
                 7.40980 
                 1.49700 
                 81.6 
               
               
                  5 
                 373.40520 
                 Variable 
               
               
                  6 
                 −52.72810 
                 0.90000 
                 1.75670 
                 36.3 
               
               
                  7 
                 26.40860 
                 2.97170 
                 1.82114 
                 24.1 
               
               
                  8 
                 −861.19410 
                 1.00000 
               
               
                  9 
                 −421.29720 
                 0.80000 
                 1.75670 
                 36.3 
               
               
                 10 
                 19.82580 
                 2.47080 
                 1.84666 
                 23.8 
               
               
                 11 
                 50.87700 
                 Variable 
               
               
                 12 (Aperture) 
                 ∞ 
                 1.50000 
               
               
                 13 
                 203.59460 
                 1.63710 
                 1.59380 
                 61.4 
               
               
                 14 
                 −85.30760 
                 0.19920 
               
               
                 15 
                 91.20520 
                 2.64410 
                 1.52540 
                 70.5 
               
               
                 16 
                 −31.81360 
                 0.90020 
                 1.83918 
                 23.9 
               
               
                 17 
                 −60.29420 
                 Variable 
               
               
                 18 
                 −99.01460 
                 2.94700 
                 1.52540 
                 70.5 
               
               
                 19 
                 −22.70510 
                 1.00040 
                 1.84666 
                 23.8 
               
               
                 20 
                 −54.22510 
                 6.00000 
               
               
                 21 
                 138.03640 
                 2.71030 
                 1.80518 
                 25.5 
               
               
                 22 
                 −60.84110 
                 Variable 
               
               
                 23 
                 −97.88170 
                 0.77430 
                 1.49700 
                 81.6 
               
               
                 24 
                 31.95350 
                 Variable 
               
               
                 25 
                 ∞ 
                 4.20000 
                 1.51680 
                 64.2 
               
               
                 26 
                 ∞ 
                 BF 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 14-1 
               
             
             
               
                   
               
               
                 (various data) 
               
               
                 Zooming ratio 3.03537 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                   
                 Focal length 
                 41.2032 
                 89.4043 
                 194.0453 
               
               
                   
                 F number 
                 3.78895 
                 3.83625 
                 6.26967 
               
               
                   
                 View angle 
                 16.2596 
                 7.0951 
                 3.2212 
               
               
                   
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                   
                 Overall length of 
                 131.4548 
                 146.9379 
                 171.9059 
               
               
                   
                 lens system 
               
               
                   
                 BF 
                 1.03034 
                 1.02675 
                 0.90588 
               
               
                   
                 d0 
                 ∞ 
                 ∞ 
                 ∞ 
               
               
                   
                 d5 
                 2.5000 
                 40.8069 
                 49.0288 
               
               
                   
                 d11 
                 30.8728 
                 15.8915 
                 1.4999 
               
               
                   
                 d17 
                 14.2711 
                 4.6788 
                 17.4979 
               
               
                   
                 d22 
                 27.3576 
                 19.4750 
                 1.6000 
               
               
                   
                 d24 
                 6.9999 
                 16.6358 
                 52.9503 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 14-2 
               
             
             
               
                   
               
               
                 (various data) 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                 Focal length 
                 40.8452 
                 86.3119 
                 125.0668 
               
               
                 F number 
                 3.79514 
                 3.87060 
                 4.85795 
               
               
                 View angle 
                 16.2338 
                 7.0456 
                 4.6874 
               
               
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                 Overall length of 
                 131.4911 
                 147.0370 
                 160.4176 
               
               
                 lens system 
               
               
                 BF 
                 1.06657 
                 1.12591 
                 1.08122 
               
               
                 d0 
                 4000.0000 
                 4000.0000 
                 4000.0000 
               
               
                 d5 
                 2.5000 
                 40.8069 
                 46.4214 
               
               
                 d11 
                 30.8728 
                 15.8915 
                 10.0988 
               
               
                 d17 
                 13.9532 
                 3.5098 
                 12.8857 
               
               
                 d22 
                 27.6755 
                 20.6440 
                 11.5067 
               
               
                 d24 
                 6.9999 
                 16.6358 
                 30.0007 
               
               
                   
               
             
          
         
       
     
       Numerical Example 7 
       [0205]    The zoom lens system of Numerical Example 7 corresponds to Embodiment 7 shown in  FIG. 25 . The data of the zoom lens system according to Numerical Example 7 is shown in the following tables. 
         [0000]    
       
         
               
             
               
               
               
               
               
             
           
               
                 TABLE 15 
               
             
             
               
                   
               
               
                 (surface data) 
               
             
          
           
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                 Variable 
                   
                   
               
               
                  1 
                 133.97580 
                 1.50000 
                 1.87800 
                 38.2 
               
               
                  2 
                 54.58420 
                 5.00400 
                 1.50670 
                 70.5 
               
               
                  3 
                 1075.41130 
                 0.19360 
               
               
                  4 
                 43.51440 
                 5.40920 
                 1.51728 
                 69.7 
               
               
                  5 
                 242.29340 
                 Variable 
               
               
                  6 
                 −80.32780 
                 0.90000 
                 1.75670 
                 36.3 
               
               
                  7 
                 24.31060 
                 2.81800 
                 1.82114 
                 24.1 
               
               
                  8 
                 152.98760 
                 1.00000 
               
               
                  9 
                 −1049.55300 
                 1.00000 
                 1.75670 
                 36.3 
               
               
                 10 
                 24.15810 
                 2.30750 
                 1.84666 
                 23.8 
               
               
                 11 
                 59.62080 
                 Variable 
               
               
                 12 (Aperture) 
                 ∞ 
                 1.50000 
               
               
                 13 
                 143.63780 
                 1.88880 
                 1.66547 
                 55.2 
               
               
                 14 
                 −74.54950 
                 0.20050 
               
               
                 15 
                 44.83610 
                 3.29630 
                 1.52540 
                 70.5 
               
               
                 16 
                 −32.57430 
                 0.90000 
                 1.84666 
                 23.9 
               
               
                 17 
                 −172.05390 
                 Variable 
               
               
                 18 
                 52.13910 
                 2.37690 
                 1.78470 
                 26.1 
               
               
                 19 
                 −78.22600 
                 0.99990 
                 1.82027 
                 29.7 
               
               
                 20 
                 37.68050 
                 Variable 
               
               
                 21 
                 141.35740 
                 2.37490 
                 1.70154 
                 41.1 
               
               
                 22 
                 −51.35740 
                 Variable 
               
               
                 23 
                 −46.71740 
                 0.77430 
                 1.49700 
                 81.6 
               
               
                 24 
                 55.22610 
                 Variable 
               
               
                 25 
                 ∞ 
                 4.20000 
                 1.51680 
                 64.2 
               
               
                 26 
                 ∞ 
                 BF 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 16-1 
               
             
             
               
                   
               
               
                 (various data) 
               
               
                 Zooming ratio 4.38517 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                   
                 Focal length 
                 41.2015 
                 89.3994 
                 194.1600 
               
               
                   
                 F number 
                 3.90425 
                 4.07258 
                 7.14509 
               
               
                   
                 View angle 
                 15.9191 
                 7.0860 
                 3.2323 
               
               
                   
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                   
                 Overall length of 
                 130.0317 
                 149.2917 
                 169.9737 
               
               
                   
                 lens system 
               
               
                   
                 BF 
                 1.03191 
                 0.94925 
                 0.97392 
               
               
                   
                 d0 
                 ∞ 
                 ∞ 
                 ∞ 
               
               
                   
                 d5 
                 2.5522 
                 38.3334 
                 43.0238 
               
               
                   
                 d11 
                 38.3240 
                 19.3298 
                 1.5000 
               
               
                   
                 d17 
                 11.6995 
                 14.2015 
                 5.0616 
               
               
                   
                 d20 
                 4.4053 
                 9.3079 
                 12.2129 
               
               
                   
                 d22 
                 26.3749 
                 18.5146 
                 3.0265 
               
               
                   
                 d24 
                 7.0000 
                 10.0114 
                 65.5311 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 16-2 
               
             
             
               
                   
               
               
                 (various data) 
               
             
          
           
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
                   
               
             
          
           
               
                 Focal length 
                 40.9681 
                 86.6940 
                 180.6754 
               
               
                 F number 
                 3.92458 
                 4.12550 
                 7.33808 
               
               
                 View angle 
                 15.8152 
                 6.9747 
                 3.1428 
               
               
                 Image height 
                 11.0300 
                 11.0300 
                 11.0300 
               
               
                 Overall length of 
                 130.0471 
                 149.3164 
                 170.0282 
               
               
                 lens system 
               
               
                 BF 
                 1.04716 
                 0.97387 
                 1.02829 
               
               
                 d0 
                 4000.0000 
                 4000.0000 
                 4000.0000 
               
               
                 d5 
                 2.5522 
                 38.3334 
                 43.0238 
               
               
                 d11 
                 38.3240 
                 19.3298 
                 1.5000 
               
               
                 d17 
                 12.9797 
                 19.4535 
                 12.2746 
               
               
                 d20 
                 3.1252 
                 4.0559 
                 5.0000 
               
               
                 d22 
                 26.3749 
                 18.5146 
                 3.0265 
               
               
                 d24 
                 7.0000 
                 10.0114 
                 65.5311 
               
               
                   
               
             
          
         
       
     
         [0206]    The following Tables show values corresponding to the individual conditions in the zoom lens systems of the numerical examples. 
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 17 
               
             
             
               
                   
               
               
                 (corresponding values to individual conditions: 
               
               
                 Numerical Examples 1 to 4) 
               
             
          
           
               
                   
                 Numerical Example 
                   
               
             
          
           
               
                   
                 Condition 
                 1 
                 2 
                 3 
                 4 
               
               
                   
                   
               
             
          
           
               
                   
                 (1) |f BAK /f F |/(f T /f W ) 
                 2.015 
                 0.644 
                 0.321 
                 0.139 
               
               
                   
                 (2) |f BAK /f F |/f W   
                 0.229 
                 0.068 
                 0.037 
                 0.016 
               
               
                   
                 (3) |f F /f of | 
                 0.577 
                 0.674 
                 1.279 
                 1.847 
               
               
                   
                 (4) |f O /f W | 
                 0.800 
                 0.756 
                 0.747 
                 2.213 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 18 
               
             
             
               
                   
               
               
                 (corresponding values to individual conditions: 
               
               
                 Numerical Examples 5 to 7) 
               
             
          
           
               
                   
                 Numerical Example 
               
             
          
           
               
                   
                 Condition 
                 5 
                 6 
                 7 
               
               
                   
                   
               
             
          
           
               
                   
                 (1) |f BAK /f F |/(f T /f W ) 
                 1.438 
                 0.166 
                 0.160 
               
               
                   
                 (2) |f BAK /f F |/f W   
                 0.130 
                 0.019 
                 0.018 
               
               
                   
                 (3) |f F /f of | 
                 0.480 
                 1.970 
                 4.699 
               
               
                   
                 (4) |f O /f W | 
                 0.729 
                 1.752 
                 2.177 
               
               
                   
                   
               
             
          
         
       
     
         [0207]    The zoom lens system according to the present invention is applicable to a digital input device such as a digital still camera, a digital video camera, a mobile telephone, a PDA (Personal Digital Assistance), a surveillance camera in a surveillance system, a Web camera or a vehicle-mounted camera. In particular, the present zoom lens system is suitable for an imaging device in a digital still camera, a digital video camera or the like that requires high image quality. 
         [0208]    Details of the present invention have been described above. However, the above-mentioned description is completely illustrative from every point of view, and does not limit the scope of the present invention. Obviously, various improvements and modifications can be performed without departing from the scope of the present invention.