Patent Publication Number: US-8120850-B2

Title: Zoom lens system, interchangeable lens apparatus and camera system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based on Japanese Patent Application No. 2009-020091 filed on Jan. 30, 2009. Hereby, the contents of Japanese Patent Application No. 2009-020091 are incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     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. Further, the present invention relates to an interchangeable lens apparatus and a camera system that employ this zoom lens system. 
     2. Description of the Background Art 
     In recent years, interchangeable-lens type digital cameras are rapidly spreading. The interchangeable-lens type digital camera is a camera system 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. Zoom lens systems applicable to the above interchangeable-lens type digital camera are disclosed in Japanese Laid-Open Patent Publication No. 2005-284097, Japanese Laid-Open Patent Publication No. 2005-352057, Japanese Laid-Open Patent Publication No. 2006-221092, Japanese Laid-Open Patent Publication No. 2005-316396, Japanese Laid-Open Patent Publication No. 2006-267425, Japanese Laid-Open Patent Publication No. 2007-219315, Japanese Laid-Open Patent Publication No. 2008-3195, and Japanese Laid-Open Patent Publication No. 2008-15251. 
     On the other hand, there are interchangeable-lens type digital cameras employing a function of displaying image data generated by the imaging lens system or the image sensor on a display unit such as a liquid crystal display or the like of a camera body (hereinafter referred to as “live view function”) (e.g., Japanese Laid-Open Patent Publication No. 2000-111789 and Japanese Laid-Open Patent Publication No. 2000-333064). 
     In the interchangeable-lens type digital cameras disclosed in Japanese Laid-Open Patent Publication No. 2000-111789 and Japanese Laid-Open Patent Publication No. 2000-333064, when the live view function is being performed, a contrast AF method is employed to perform focusing operation. The contrast AF is the focusing operation based on the contrast value of image data obtained from the image sensor. Hereinafter, an operation of the contrast AF will be described. 
     First, the interchangeable-lens type digital camera oscillates the focusing lens unit in the optical axis direction at a high-speed (hereinafter referred to as “wobbling”) thereby to detect the direction of displacement from an in-focus condition. After the wobbling, the interchangeable-lens type digital camera detects, from an output signal of the image sensor, signal components in a predetermined frequency band in an image region and calculates an optimal position of the focusing lens unit for realizing the in-focus condition. Thereafter, the interchangeable-lens type digital camera moves the focusing lens unit to the optimal position, and completes the focusing operation. When the focusing operation is performed continuously in video image taking or the like, the interchangeable-lens type digital camera repeats a series of the above operations. 
     Generally, 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, video image taking using the interchangeable-lens type digital camera also need be performed at the same rate of 30 frames per second. Accordingly, the focusing lens unit need be driven at the high rate of 30 Hz at the time of wobbling. 
     However, if the weight of the focusing lens unit is large, a larger motor or actuator is required to move the focusing lens unit at a high rate. This causes a problem that the outer diameter of the lens barrel is increased. However, in the case of the zoom lens systems for the interchangeable-lens type digital camera disclosed in the above conventional arts, the focusing lens unit is hardly light-weighted. 
     Further, in the interchangeable-lens type digital camera, it should be noted that the size of the image corresponding to a photographic object varies in association with wobbling. This variation in the image is caused mainly by the fact that the movement of the focusing lens unit in the optical axis direction 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, the image taking person will feel uneasiness. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a zoom lens system which includes a compactly constructed focusing lens unit and which has a suppressed change in the image magnification at the time of movement of the focusing lens unit, and an interchangeable lens apparatus and a camera system which employ this zoom lens system. 
     A zoom lens system according to the present invention, in order from an object side to an image side, includes: a first lens unit having positive optical power; a second lens unit having negative optical power; a third lens unit having negative optical power; and a fourth lens unit having positive optical power. At the time of zooming, at least the first lens unit moves from a wide-angle limit to a telephoto limit. The fourth lens unit includes a first sub lens unit having positive optical power and a second sub lens unit having negative optical power, the second sub lens unit being arranged at the image side relative to the first sub lens unit. At the time of compensating image blur caused by vibration applied to the zoom lens system, the first sub lens unit or the second sub lens unit moves in a direction perpendicular to the optical axis. 
     Further, an interchangeable lens apparatus according to the present invention includes: any of the above zoom lens systems; and a mount section detachably connected to a camera body that includes an image sensor which receives an optical image formed by the zoom lens system thereby to convert the optical image to an electrical image signal. 
     Moreover, a camera system according to the present invention includes: an interchangeable lens apparatus including any of the above zoom lens systems; and a camera body which is connected to the interchangeable lens apparatus via a camera mount section in an attachable and removable manner and includes an image sensor which receives an optical image formed by the zoom lens system thereby to convert the optical image to an electrical image signal. 
     According to the present invention, it is possible to provide a zoom lens system which includes a compactly constructed focusing lens unit and which has a suppressed change in image magnification at the time of movement of the focusing lens unit, and an interchangeable lens apparatus and a camera system which employ the zoom lens system. 
     These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 1 (Example 1); 
         FIG. 2  is a longitudinal aberration diagram showing an infinity in-focus condition of a zoom lens system according to Example 1; 
         FIG. 3  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; 
         FIG. 4  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 2 (Example 2); 
         FIG. 5  is a longitudinal aberration diagram showing an infinity in-focus condition of a zoom lens system according to Example 2; 
         FIG. 6  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; 
         FIG. 7  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 3 (Example 3); 
         FIG. 8  is a longitudinal aberration diagram showing an infinity in-focus condition of a zoom lens system according to Example 3; 
         FIG. 9  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; 
         FIG. 10  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 4 (Example 4); 
         FIG. 11  is a longitudinal aberration diagram showing an infinity in-focus condition of a zoom lens system according to Example 4; 
         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 4; 
         FIG. 13  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 5 (Example 5); 
         FIG. 14  is a longitudinal aberration diagram showing an infinity in-focus condition of a zoom lens system according to Example 5; 
         FIG. 15  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; and 
         FIG. 16  is a schematic construction diagram of a camera system according to Embodiment 6. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1 ,  4 ,  7 ,  10 , and  13  show lens arrangement diagrams of zoom lens systems according to Embodiments 1, 2, 3, 4, and 5, respectively, and each show a zoom lens system in a infinity in-focus condition. 
     In each diagram, 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 =√(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 diagram, each bend arrow located between part (a) and part (b) indicates a line obtained by connecting the positions of the lens units respectively at a wide-angle limit, a middle position, and a telephoto limit, in order from the top. 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 diagram, 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. 
     In  FIGS. 1 ,  4 ,  7 ,  10 , and  13 , an asterisk “*” imparted to a particular surface indicates that the surface is aspheric. Further, in each diagram, symbol (+) or symbol (−) imparted to the symbol of each lens unit corresponds to the sign of the optical power of the lens unit. Still further, in each diagram, the straight line located on the most right-hand side indicates the position of the image surface S. On the object side relative to the image surface S (between the image surface S and a surface of a lens closest to the image side in the fourth lens unit G 4 ), there is arranged a parallel plate P which corresponds to an optical low-pass filter, a face plate of an image sensor, or the like. Further, in each diagram, an aperture diaphragm A is arranged on the object side relative to the fourth lens unit G 4  while an interval which does not change at the time of zooming is arranged therebetween. 
     The zoom lens system according to each of Embodiments 1 to 5, in order from the object side to the image side, includes 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, and a fourth lens unit G 4  having positive optical power. 
     Embodiments 1 to 3 
     The first lens unit G 1 , in order from the object side to the image side, includes: 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. 
     The second lens unit G 2 , in order from the object side to the image side, includes: a negative meniscus fourth lens element L 4  with the convex surface facing the object side; a negative meniscus fifth lens element L 5  with the convex surface facing the image side; and a bi-convex sixth lens element L 6 . The fourth lens element L 4  is a hybrid lens obtained by cementing a transparent resin layer formed of a UV cured resin onto a surface of the lens element facing the object side. The hybrid lens has an aspheric surface formed of a transparent resin layer. Accordingly, it is possible to form a large diameter aspheric surface which is difficult to obtain by only press-molding of glass. Further, as compared to the case where the lens element is formed of a resin only, the hybrid lens is stable against temperature variation in terms of both refractive-index variation and shape variation, and thus it is possible to provide a lens element having a high refractive index. 
     The third lens unit G 3  includes: a bi-concave seventh lens element L 7 . Both surfaces of the seventh lens element L 7  are aspheric. 
     The fourth lens unit G 4 , in order from the object side to the image side; includes: a bi-convex eighth lens element L 8 ; a bi-convex ninth lens element L 9 ; a bi-concave tenth lens element L 10 ; a bi-convex eleventh lens element L 11 , a bi-convex twelfth lens element L 12 ; a bi-concave thirteenth lens element L 13 ; a bi-convex fourteenth lens element L 14 ; a negative meniscus fifteenth lens element L 15  with the convex surface facing the image side; a negative meniscus sixteenth lens element L 16  with the convex surface facing the image side; and a bi-convex seventeenth lens element L 17 . The ninth lens element L 9  and the tenth lens element L 10  are cemented with each other. The twelfth lens element L 12  and the thirteenth lens element L 13  are cemented with each other. Moreover, the fourteenth lens element L 14  and the fifteenth lens element L 15  are cemented with each other. Further, both surfaces of the eighth lens element L 8  and a surface of the eleventh lens element L 11  facing the image side are aspheric. 
     Embodiment 4 
     The first lens unit G 1 , in order from the object side to the image side, includes: 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. 
     The second lens unit G 2 , in order from the object side to the image side, includes: a negative meniscus fourth lens element L 4  with the convex surface facing the object side; a negative meniscus fifth lens element L 5  with the convex surface facing the image side; and a bi-convex sixth lens element L 6 . A surface of the fourth lens element L 4  facing the object side is aspheric. 
     The third lens unit G 3  includes: a bi-concave seventh lens element L 7 . Both surfaces of the seventh lens element L 7  are aspheric. 
     The fourth lens unit G 4 , in order from the object side to the image side; includes: a bi-convex eighth lens element L 8 ; a bi-convex ninth lens element L 9 ; a bi-concave tenth lens element L 10 ; a bi-convex eleventh lens element L 11 , a bi-convex twelfth lens element L 12 ; a bi-concave thirteenth lens element L 13 ; a bi-convex fourteenth lens element L 14 ; a negative meniscus fifteenth lens element L 15  with the convex surface facing the image side; a negative meniscus sixteenth lens element L 16  with the convex surface facing the image side; and a bi-convex seventeenth lens element L 17 . The ninth lens element L 9  and the tenth lens element L 10  are cemented with each other. The twelfth lens element L 12  and the thirteenth lens element L 13  are cemented with each other. Moreover, the fourteenth lens element L 14  and the fifteenth lens element L 15  are cemented with each other. Further, both surfaces of the eighth lens element L 8  and a surface of the eleventh lens element L 11  facing the image side are aspheric. 
     Embodiment 5 
     The first lens unit G 1 , in order from the object side to the image side, includes: 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. 
     The second lens unit G 2 , in order from the object side to the image side, includes: a negative meniscus fourth lens element L 4  with the convex surface facing the object side; a negative meniscus fifth lens element L 5  with the convex surface facing the image side; and a bi-convex sixth lens element L 6 . A surface of the fourth lens element L 4  facing the object side is aspheric. 
     The third lens unit G 3  includes: a bi-concave seventh lens element L 7 . Both surfaces of the seventh lens element L 7  are aspheric. 
     The fourth lens unit G 4 , in order from the object side to the image side; includes: a bi-convex eighth lens element L 8 ; a positive meniscus ninth lens element L 9  with the convex surface facing the object 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 ; a bi-concave thirteenth lens element L 13 ; a bi-convex fourteenth lens element L 14 ; a negative meniscus fifteenth lens element L 15  with the convex surface facing the image side; a bi-convex sixteenth lens element L 16 ; and a negative meniscus seventeenth lens element L 17  with the convex surface facing the image side. The ninth lens element L 9  and the tenth lens element L 10  are cemented with each other. The twelfth lens element L 12  and the thirteenth lens element L 13  are cemented with each other. Moreover, the sixteenth lens element L 16  and the seventeenth lens element L 17  are cemented with each other. Further, both surfaces of the eighth lens element L 8  and a surface of the fifteenth lens element L 15  facing the image side are aspheric. 
     The zoom lens system according to each of the embodiments changes intervals among respective lens units at the time of zooming such that: the interval between the first lens unit G 1  and the second lens unit G 2  is made longer at a telephoto limit than the interval at a wide-angle limit; the interval between the second lens unit G 2  and the third lens unit G 3  is made longer at a telephoto limit than the interval at a wide-angle limit; and the interval between the third lens unit G 3  and the fourth lens unit G 4  is made shorter at a telephoto limit than the interval at a wide-angle limit. 
     More specifically, 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 monotonously to the object side such that: the interval between the first lens unit G 1  and the second lens unit G 2 , and the interval between the second lens unit G 2  and the third lens unit G 3  are increased, respectively; whereas the interval between the third lens unit G 3  and the fourth lens unit G 4  is decreased. It is noted that in any of the embodiments, the aperture diaphragm A moves to the object side together with the fourth lens unit G 4 . 
     Further, at the time of focusing from an infinity in-focus condition to a close-point in-focus condition, the third lens unit G 3  moves to the object side along the optical axis. 
     To allow video taking, the focusing lens unit need have high-speed response while wobbling operation. In the zoom lens system according to each of the above Embodiments 1 to 5, the third lens unit G 3  is composed of one lens element, whereby a focusing lens unit having a reduced weight and high-speed response is realized. It is noted that the focusing lens unit need not necessarily be formed of one lens element. If the torque performance of the actuator allows, the focusing lens unit may includes two lens elements. Further, in order to minimize fluctuation in performance in focusing from infinity to a close-point distance, the focusing lens unit has an aspheric surface. The aspheric surface may be a hybrid aspheric surface. 
     In the zoom lens system according to Embodiments 1 to 5, the fourth lens unit G 4  is arranged closest to the object side, and includes: a first sub lens unit having positive optical power; a second sub lens unit having negative optical power and arranged on the image side relative to the first sub lens unit; and a third sub lens unit having positive optical power and arranged closest to the image side. It is noted that the sub lens unit represents, when one lens unit includes a plurality of lens elements, any one of lens elements or a combination of adjoining lens elements included in the lens unit. 
     More specifically, in Embodiments 1 to 5, in the fourth lens unit G 4 , the eighth lens element L 8 , the ninth lens element L 9 , the tenth lens element L 10 , and the eleventh lens element L 11  form a first sub lens unit, and the twelfth lens element L 12  and the thirteenth lens element L 13  form a second sub lens unit. Further, the fourteenth lens element L 14 , the fifteenth lens element L 15 , the sixteenth lens element L 16 , and the seventeenth lens element L 17  form a third sub lens unit. 
     At the time of image blur compensation for compensating image blur caused by vibration applied to the zoom lens, the first sub lens unit or the second sub lens unit moves in a direction perpendicular to the optical axis. More specifically, in Embodiments 1, 2, 4, and 5, the second sub lens unit moves in a direction perpendicular to the optical axis to compensate the movement of an image point caused by vibration applied to the entire system, whereas in Embodiment 3, the first sub lens unit moves in a direction perpendicular to the optical axis to compensate the movement of an image point caused by vibration applied to the entire system. 
     To obtain an sufficient optical image blur compensation effect, the sub lens unit moving in a direction perpendicular to the optical axis need have high-speed response. In above Embodiments 1, 2, 4, and 5, the second sub lens unit for compensating the movement of an image point is formed of two lens elements, whereby the sub lens unit having a reduced weight and high-speed response is realized. When the sub lens unit for image blur compensation is formed of two lens elements, it is possible to suppress, to an allowable range, field curvature aberration or chromatic aberration which is generated at the time of image blur compensation at the image height in a diagonal direction on the image surface, and consequently it is possible to obtain desired imaging characteristics. It is noted, however, that the configuration of the sub lens unit for image blur compensation varies depending on the characteristics required for the zoom lens system. When the allowable range of the field curvature aberration or chromatic aberration is broad, the sub lens unit for image blur compensation may be formed of one lens element. 
     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 the 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 a corresponding effect can be obtained. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
0.6 &lt;f   4A   /f   4α &lt;1.0  (1)
 
     where, 
     f 4A  is a focal length of the first sub lens unit in the case where the fourth lens unit includes the first sub lens unit having positive optical power and the second sub lens unit arranged on the image side relative to the first sub lens unit and having negative optical power, and 
     f 4α  is a composite focal length of the fourth lens unit and a lens unit subsequent thereto at a wide-angle limit. 
     The condition (1) sets forth the ratio between the focal length of the first sub lens unit included in the fourth lens unit and the composite focal length of the fourth lens unit and a lens unit subsequent thereto. When the value exceeds the upper limit of the condition (1), the field curvature at a wide-angle limit becomes excessive toward the under side. Thus, this situation is unpreferable. On the other hand, when the value goes below the lower limit of the condition (1), the back focus is elongated, and thus the overall length cannot be compact. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
0.6 &lt;f   4Ob   /f   4α &lt;1.0  (2)
 
     where, 
     when the fourth lens unit, in order from the object side to the image side, includes: a lens element having positive optical power; a lens element having positive optical power; a lens element having negative optical power; and a lens element having positive optical power, f 4Ob  is a composite focal length of the four lens elements, and 
     f 4α  is a composite focal length of the fourth lens unit and a lens unit subsequent thereto at a wide-angle limit. 
     The condition (2) sets forth the ratio between the composite focal length of four lens elements arranged closest to the object side in the fourth lens unit and the composite focal length of the fourth lens unit and a lens unit subsequent thereto. When the value exceeds the upper limit of the condition (2), the field curvature at a wide-angle limit becomes excessive toward the under side. When the value goes below the lower limit of the condition (2), the back focus is elongated, and the overall length cannot be compact. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
−1.5 &lt;f   4B   /f   4α &lt;−0.9  (3)
 
     where, 
     f 4B  is a focal length of the second sub lens unit in the case where the fourth lens unit includes the first sub lens unit having positive optical power, and the second sub lens unit arranged on the image side relative to the first sub lens unit and having negative optical power, and 
     f 4α  is a composite focal length of the fourth lens unit and a lens unit subsequent thereto at a wide-angle limit. 
     The condition (3) sets forth the ratio between the focal length of the second sub lens unit included in the fourth lens unit and the composite focal length of the fourth lens unit and a lens unit subsequent thereto. In the case where the second sub lens unit is moved in a direction perpendicular to the optical axis for the purpose of image blur compensation, when the value exceeds the upper limit of the condition (3), the amount of blur compensation increases, which leads to upsizing of a blur compensation mechanism. Thus, this situation is unpreferable. In contrast, when the value goes below the lower limit of the condition (3), sensitivity at the time of blur compensation increases, and it becomes difficult to maintain accuracy of the position control required for blur compensation. Thus, this situation is unpreferable. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
3.0 &lt;f   4Im   /f   4α &lt;4.5  (4)
 
     where, 
     when the fourth lens unit, in order from the image side to the object side, includes; a lens element having positive optical power; a lens element having negative optical power; a lens element having negative optical power; and a lens element having positive optical power, f 4Im , is a composite focal length of the four lens elements; and 
     f 4α  is a composite focal length of the fourth lens unit and a lens unit subsequent thereto at a wide-angle limit. 
     The condition (4) sets forth the ratio between the composite focal length of four lens elements arranged closest to the object side in the fourth lens unit and the composite focal length of the fourth lens unit and a lens unit subsequent thereto. When the value exceeds the upper limit of the condition (4), the distortion at a wide-angle limit becomes excessive toward the over side. Thus, this situation is unpreferable. Further, the value goes below the lower limit of the condition (4), the back focus is elongated, and the overall length cannot be compact. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
1.0 &lt;f   4α   /f   W &lt;1.5  (5)
 
     where, 
     f 4α  is a composite focal length of the fourth lens unit and a lens unit subsequent thereto at a wide-angle limit, and 
     f W  is a focal length of the entire system at a wide-angle limit. 
     The condition (5) sets forth the focal length of the fourth lens unit and a lens unit subsequent thereto. When the value exceeds the upper limit of the condition (5), the incident angle relative to the image surface is increased, and it becomes difficult to secure the telecentricity. Further, when the value goes below the lower limit of the condition (5), it is not desirable since the flange back cannot be obtained. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
−1.6 &lt;f   F   /f   4α &lt;−0.7  (6)
 
     where, 
     f F  is a focal length of the focusing lens unit, and 
     f 4α  is a composite focal length of the fourth lens unit and a lens unit subsequent thereto at a wide-angle limit. 
     The condition (6) sets forth the ratio between the focal length of the focusing lens unit and the composite focal length of the fourth lens unit and a lens unit subsequent thereto. When the value exceeds the upper limit of the condition (6), the fluctuation in the field curvature at the time of focusing increases. Thus, this situation is unpreferable. Further, when the value goes below the lower limit of the condition (6), it may cause upsizing of the optical system when the amount of movement in association with focusing is large. Thus, this situation is unpreferable. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
12 &lt;f   1 *( f   T   /f   W )/√{square root over (( f   W   *f   T ))}&lt;27  (7)
 
     where, 
     f 1  is a focal length of the first lens unit, 
     f T  is a focal length of the entire system at a telephoto limit, and 
     f W  is a focal length of the entire system at a wide-angle limit. 
     The condition (7) sets forth the relation between the focal length of the first lens unit and the focal length of the entire system. When the value exceeds the upper limit of the condition (7), it causes an increase in the amount of movement of the first unit from a wide-angle limit to a telephoto limit, and as a result, an intersection angle (pressure angle) of the cam become acute, resulting in fluctuation in load of the cam. Thus, this situation is unpreferable. Further, when the value goes below the lower limit of the condition (7), it becomes difficult to compensate the magnification chromatic aberration generated in the first lens unit by using the subsequent lens units. Thus, this situation is unpreferable. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
−20 &lt;f   2 *( f   T   /f   W )/√{square root over (( f   W   *f   T ))}&lt;−6  (8)
 
     where, 
     f 2  is a focal length of the second lens unit, 
     f T  is a focal length of the entire system at a telephoto limit, and 
     f W  is a focal length of the entire system at a wide-angle limit. 
     The condition (8) sets forth the relation between the focal length of the second lens unit and the focal length of the entire system. When the value exceeds the upper limit of the condition (8), the negative optical power of the second lens unit is excessively increased, and the field curvature is apt to be toward the under side, and as a result, the difference in the peripheral image surface increases between the wide-angle limit and the telephoto limit at the time of variation of magnification. Thus, the situation is not preferable. Further, when the value goes below the lower limit of the condition (8), the negative optical power of the second lens unit is excessively decreased, and the field curvature is apt to be toward the over side, and as a result, the difference in the peripheral image surface increases between the wide-angle limit and the telephoto limit at the time of variation of magnification. Thus, this situation is not preferable. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
0.5 &lt;δt   1   /f   1 &lt;1.1  (9)
 
     where, 
     δt 1  is an amount of movement of the first lens unit from a wide-angle limit to a telephoto limit (where, the position of the wide-angle limit is set as the reference, and expansion to the object side from the reference position is regarded as a positive value), and 
     f 1  is a focal length of the first lens unit. 
     The condition (9) sets forth the amount of movement of the first lens unit in the optical axis direction. When the value exceeds the upper limit of the condition (9), with a moving mechanism of the first lens unit being configured with a cam, it is difficult to smoothly form the curve of the cam groove. When the value of the condition (9) goes below the lower limit, the overall length is elongated at a wide-angle limit, or the overall length is shortened at a telephoto limit. When the overall length is elongated at a wide-angle limit, a front lens diameter increases. Thus, this is unpreferable. On the other hand, when the overall length is shortened at a telephoto limit, the sensitivity of the first lens unit increases. This situation is unpreferable from the viewpoint of manufacturing. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
−0.7 &lt;δt   2   /f   2 &lt;−0.2  (10)
 
     where, 
     δt 2  is an amount of movement of the second lens unit from a wide-angle limit to a telephoto limit (where, the position of the wide-angle limit is set as the reference, and expansion to the object side from the reference position is regarded as a positive value), and 
     f 2  is a focal length of the second lens unit. 
     The condition (10) sets forth the amount of movement of the second lens unit in the optical axis direction. When the value exceeds the upper limit of the condition (10), the position of the incident pupil moves considerably deeply to the image surface side, which causes increase in the front lens diameter. Thus, this situation is unpreferable. Further, when the value goes below the lower limit of the condition (10), the power of the second lens unit increases, and this causes difficulty in compensating aberration. If the aberration compensation is to be performed, the number of lenses will be increased. Thus, this situation is unpreferable. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
−1.2 &lt;δt   3   /f   3 &lt;−0.4  (11)
 
     where, 
     δt 3  is an amount of movement of the third lens unit from a wide-angle limit to a telephoto limit (where, the position of the wide-angle limit is set as the reference, and expansion to the object side from the reference position is regarded as a positive value), and 
     f 3  is a focal length of the third lens unit. 
     The condition (11) sets forth the amount of movement of the third lens unit in the optical axis direction. When the value exceeds the upper limit of the condition (11), upsizing of the actuator for focusing will be caused. Thus, this situation is unpreferable. Further, when the value goes below the lower limit of the condition (11), the power of the third lens unit increases, and sensitivity for decentering increases. Thus, this situation is unpreferable. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
1.2 &lt;δt   4   /f   4 &lt;2.0  (12)
 
     where, 
     δt 4  is an amount of movement of the fourth lens unit from a wide-angle limit to a telephoto limit (where, the position of the wide-angle limit is set as the reference, and expansion to the object side from the reference position is regarded as a positive value), and 
     f 4  is a focal length of the fourth lens unit. 
     The condition (12) sets forth the amount of movement of the fourth lens unit in the optical axis direction. When the value exceeds the upper limit of the condition (12), the overall length of the entire system is elongated at a telephoto limit, and thus the amount of movement of the first lens unit from a wide-angle limit to a telephoto limit increases. When a moving mechanism of the first lens unit is configured with a cam, the intersection angle (pressure angle) of the cam becomes acute, resulting in fluctuation in load of the cam. Thus, this situation is unpreferable. Further, when the value goes below the lower limit of the condition (12), the power of the second lens unit increases, and fluctuation in the field curvature increases from a wide-angle limit to a telephoto limit, which cause difficulty in its compensation. Thus, this situation is unpreferable. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
−25&lt;β 2T /β 2W &lt;34  (13)
 
     where, 
     β 2T  is paraxial imaging magnification of the second lens unit at a telephoto limit, and 
     β 2W  is paraxial imaging magnification of the second lens unit at a wide-angle limit. 
     The condition (13) sets forth the change in magnification of the second lens unit. When the value exceeds the upper limit of the condition (13), it becomes difficult to compensate aberration from a wide-angle limit to a telephoto limit. Thus, this situation is unpreferable. Further, when the value goes below the lower limit of the condition (13), the amount of movement of the second lens unit from a wide-angle limit to a telephoto limit increases, and consequently, the overall length of the entire system is elongated. Thus, this situation is unpreferable. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
−8&lt;β 3T /β 3W &lt;0.2  (14)
 
     where, 
     β 3T  is paraxial imaging magnification of the third lens unit at a telephoto limit, and 
     β 3W  is paraxial imaging magnification of the third lens unit at a wide-angle limit. 
     The condition (14) sets forth the change in magnification of the third lens unit. When the value exceeds the upper limit of the condition (14), the power of the third lens unit is increased, and fluctuation of an image at the time of focusing increases. Thus, this situation is unpreferable. Further, when the value goes below the lower limit of the condition (14), the power of the third lens unit is decreased, the amount of movement of the third lens unit at the time of focusing increases. Thus, this situation is unpreferable. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
2&lt;β 4T /β 4W &lt;3.2  (15)
 
     where, 
     β 4T  is paraxial imaging magnification of the fourth lens unit at a telephoto limit, and 
     β 4W  is paraxial imaging magnification of the fourth lens unit at a wide-angle limit. 
     The condition (15) sets forth the change in magnification of the fourth lens unit. When the value exceeds the upper limit of the condition (15), the incident angle of light to be incident on the image surface at a wide-angle limit increases, and it becomes difficult to maintain the telecentricity. Thus, this situation is unpreferable. Further, when the value goes below the lower limit of the condition (15), the back focus is elongated at a wide-angle limit, and the entire system cannot be compact. Thus, this situation is unpreferable. 
     If the focusing lens unit included in the zoom lens system according to each embodiment has an aspheric surface, it is preferable that the following condition is satisfied.
 
−0.3 &lt;f   F *β FW *β FW /(δ s   F   *f   T   /f   W )&lt;7.0  (16)
 
     where, 
     f F  is a focal length of the focusing lens unit, 
     β FW  is paraxial imaging magnification of the focusing lens unit at a wide-angle limit, 
     δs F  is an amount of deformation of an aspheric surface at a height of 0.5*f W *tan ω W  from the optical axis, the aspheric surface being arranged closest to the object side in the focusing lens unit, 
     f T  is a focal length of the entire system at a telephoto limit, 
     f W  is a focal length of the entire system at a wide-angle limit, and 
     ω W  is a half view angle at a wide-angle limit. 
     The condition (16) sets forth the relation between the paraxial imaging magnification and the amount of aspheric aberration of the focusing lens unit. When the value exceeds the upper limit of the condition (16), the astigmatism and spherical aberration from an infinity distance at a telephoto limit to a close-point distance are increased to the under side, and thus this situation is unpreferable from the viewpoint of the aberration compensation. When the value goes below the lower limit of the condition (16), the aberration sensitivity relative to process errors increases, and thus fluctuation in the field curvature caused by manufacturing variation increases. Thus, this situation is unpreferable. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
−1.7mm&lt;DIS W   *f   T   /f   W &lt;−0.5mm  (17)
 
     where, 
     DIS W  is an amount of distortion of the maximum image height at a wide-angle limit, 
     f T  is a focal length of the entire system at a telephoto limit, and 
     f W  is a focal length of the entire system at a wide-angle limit. 
     The condition (17) sets forth the relation between the amount of distortion and a variable magnification ratio. In the case where the camera system is provided with a distortion compensation system, when the value exceeds the upper limit of the condition (17), the advantage of shortening of the overall length by the above system cannot be utilized. Thus, this situation is unpreferable. In contrast, when the value goes below the lower limit of the condition (17), the image magnification rate is increased in the distortion compensation process, resulting in degradation in resolution. Thus, this situation is unpreferable. 
     In the zoom lens system according to each embodiment, it is preferable that the following condition is satisfied.
 
1.88&lt;nd 2   (18)
 
     where, 
     nd 2  is an average refractive index of a lens element (a portion excluding a resin layer in the case of a hybrid lens) included in the second lens unit. 
     When the value goes below the lower limit of the condition (18), the distortion mainly at a wide-angle limit increases due to decrease in the curvature of the lens, which causes difficulty in compensating the aberration. Thus, this situation is unpreferable. 
     Here, the individual lens units included in the zoom lens system according to each embodiment may be 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). Alternatively, the lens may be composed of any one of, or a combination of some of: 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; refractive index distribution type lens elements that deflect the incident light by distribution of refractive index in the medium, and the like. 
     Embodiment 6 
       FIG. 16  is a schematic construction diagram of a camera system according to Embodiment 6. 
     A camera system  100  according to the present embodiment includes a camera body  101 , and an interchangeable lens apparatus  201  connected to the camera body  101  in an attachable and removable manner. 
     The camera body  101  includes an image sensor  102  which receives an optical image formed by a zoom lens system  202  of the interchangeable lens apparatus  201  thereby to convert the optical image into an electric image signal, a liquid crystal display monitor  103  which displays an image signal converted by the image sensor  102 , and a camera mount section  104 . On the other hand, the interchangeable lens apparatus  201  includes the zoom lens system  202  according to any one of Embodiments 1 to 5, a lens barrel  203  which holds the zoom lens system  202 , and a lens mount section  204  connected to the camera mount section  104  of the camera body. The camera mount section  104  and the lens mount section  204  are connected to each other not only physically but also electrically, and function as interfaces. That is, a controller (not shown) inside the camera body  101  is electrically connected to a controller (not shown) inside the interchangeable lens apparatus  201 , thereby achieving mutual signal communication. 
     The camera system  100  according to the present embodiment includes the zoom lens system  202  according to any one of Embodiments 1 to 5, and hence is capable of displaying an preferable optical image at the time of focusing in a live view state. 
     EXAMPLES 
     Hereinafter, numerical examples will be described below in which the zoom lens systems according to Embodiments 1 to 5 are implemented specifically. As will be described later, Numerical Examples 1 to 5 corresponds to Embodiments 1 to 5, respectively. Here, in each numerical example, the units of the length 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 formula. 
             Z   =           h   2     /   r       1   +       1   -       (     1   +   κ     )     ⁢       (     h   /   r     )     2               +     ∑       A   n     ⁢     h   n                 
Here, the symbols in the formula indicate the following quantities:
     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;   h is the height relative to the optical axis;   r is the radius of curvature at the top;   κ is the conic constant; and   A n  is the n-th order aspheric coefficient.   

       FIGS. 2 ,  5 ,  8 ,  11 , and  14  are longitudinal aberration diagrams of an infinity in-focus condition of the zoom lens systems according to Numerical Examples 1, 2, 3, 4, and 5. 
     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 diagram, indicated as F), 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 diagram, indicated as H), the solid line and the dash line indicate the characteristics to the sagittal image plane (in each diagram, indicated as “s”) and the meridional image plane (in each diagram, indicated as “m”), respectively. In each distortion diagram, the vertical axis indicates the image height (in each diagram, indicated as H). 
       FIGS. 3 ,  6 ,  9 ,  12 , and  15  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, and 5. 
     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 at a telephoto limit where the sub lens unit (first sub lens unit or second sub lens unit) for image blur compensation included in the fourth lens unit G 4  moves by a predetermined amount in a direction perpendicular to the optical axis. Among the lateral aberration diagrams of a basic state, the upper part shows the lateral aberration at an image point of 70% 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 −70% 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 70% 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 −70% of the maximum image height. Further, 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 . 
     Here, in the zoom lens system according to each numerical example, the amount (Y T (mm)) 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. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 (Amount of movement of compensation lens unit) 
               
            
           
           
               
               
               
            
               
                   
                 Numerical Example 
                 Y T   
               
               
                   
               
               
                   
                 1 
                 0.307 
               
               
                   
                 2 
                 0.316 
               
               
                   
                 3 
                 0.135 
               
               
                   
                 4 
                 0.308 
               
               
                   
                 5 
                 0.314 
               
               
                   
               
            
           
         
       
     
     Numerical Example 1 
     The zoom lens system of Numerical Example 1 corresponds to Embodiment 1 shown in  FIG. 1 . Data of the zoom lens system according to Numerical Example 1, i.e., the surface data, the aspheric surface data, the various data, the lens element data, the zoom lens unit data, and the zoom lens unit magnification are shown in Table 2, Table 3, Table 4, Table 5, Table 6, and Table 7, respectively. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                   
                   
                   
               
               
                  1 
                 93.29160 
                 1.49730 
                 1.84666 
                 23.8 
               
               
                  2 
                 50.82680 
                 7.10180 
                 1.49700 
                 81.6 
               
               
                  3 
                 −850.01520 
                 0.15000 
                   
                   
               
               
                  4 
                 47.79330 
                 5.18430 
                 1.71300 
                 53.9 
               
               
                  5 
                 149.47070 
                 Variable 
                   
                   
               
               
                  6* 
                 76.05160 
                 0.10000 
                 1.51358 
                 51.6 
               
               
                  7 
                 53.79460 
                 1.10000 
                 1.88300 
                 40.8 
               
               
                  8 
                 11.90020 
                 6.30730 
                   
                   
               
               
                  9 
                 −20.07120 
                 0.83030 
                 1.88300 
                 40.8 
               
               
                 10 
                 −51.30870 
                 0.87050 
                   
                   
               
               
                 11 
                 31.52170 
                 3.39400 
                 1.94595 
                 18.0 
               
               
                 12 
                 −51.59310 
                 Variable 
                   
                   
               
               
                 13* 
                 −19.66880 
                 1.20040 
                 1.80470 
                 41.0 
               
               
                 14* 
                 129.88760 
                 Variable 
                   
                   
               
               
                 15(Diaphragm) 
                 ∞ 
                 0.84560 
                   
                   
               
               
                 16* 
                 23.65630 
                 3.02980 
                 1.69350 
                 53.2 
               
               
                 17* 
                 −55.43650 
                 2.59200 
                   
                   
               
               
                 18 
                 15.08640 
                 3.25030 
                 1.71300 
                 53.9 
               
               
                 19 
                 −200.75790 
                 0.81020 
                 2.00069 
                 25.5 
               
               
                 20 
                 15.26070 
                 1.91050 
                   
                   
               
               
                 21 
                 31.27490 
                 5.91480 
                 1.59201 
                 67.0 
               
               
                 22* 
                 −20.38770 
                 0.89910 
                   
                   
               
               
                 23 
                 88.68500 
                 2.96870 
                 1.80518 
                 25.5 
               
               
                 24 
                 −13.73040 
                 0.80000 
                 1.83481 
                 42.7 
               
               
                 25 
                 16.65510 
                 2.35020 
                   
                   
               
               
                 26 
                 23.27780 
                 4.19350 
                 1.49700 
                 81.6 
               
               
                 27 
                 −14.99240 
                 0.80000 
                 1.83481 
                 42.7 
               
               
                 28 
                 −57.80160 
                 1.35890 
                   
                   
               
               
                 29 
                 −14.16000 
                 0.80000 
                 1.72916 
                 54.7 
               
               
                 30 
                 −26.58250 
                 0.10000 
                   
                   
               
               
                 31 
                 32.36170 
                 3.20070 
                 1.51680 
                 64.2 
               
               
                 32 
                 −81.55460 
                 Variable 
                   
                   
               
               
                 33 
                 ∞ 
                 4.20000 
                 1.51680 
                 64.2 
               
               
                 34 
                 ∞ 
                 BF 
                   
                   
               
               
                 image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 (Aspheric surface data) 
               
            
           
           
               
               
            
               
                 Sur- 
                   
               
               
                 face 
                   
               
               
                 No. 
                 Parameters 
               
               
                   
               
            
           
           
               
               
            
               
                  6 
                 K = −9.51780E−01, A4 = 2.71746E−05, A6 = −1.19865E−08, 
               
               
                   
                 A8 = −8.37911E−10, A10 = 5.57759E−12, A12 = −1.15782E−14 
               
               
                 13 
                 K = 0.00000E+00, A4 = −3.91729E−05, A6 = 1.79189E−06, 
               
               
                   
                 A8 = −3.13080E−08, A10 = 1.39737E−10, A12 = 2.27477E−12 
               
               
                 14 
                 K = −1.79163E−01, A4 = −4.45555E−05, A6 = 2.19191E−06, 
               
               
                   
                 A8 = −5.22554E−08, A10 = 5.17499E−10, A12 = −1.04173E−13 
               
               
                 16 
                 K = 0.00000E+00, A4 = −1.12821E−05, A6 = 1.40905E−07, 
               
               
                   
                 A8 = −2.71306E−09, A10 = −7.19478E−11, A12 = −7.19829E−15 
               
               
                 17 
                 K = 0.00000E+00, A4 = 2.44778E−05, A6 = −3.84078E−08, 
               
               
                   
                 A8 = 1.18435E−09, A10 = −1.10289E−10, A12 = 7.33811E−15 
               
               
                 22 
                 K = 0.00000E+00, A4 = 1.81139E−05, A6 = −5.84158E−08, 
               
               
                   
                 A8 = 6.50501E−09, A10 = −6.84134E−11, A12 = 0.00000E+00 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 (Various data) 
               
               
                 Zooming ratio 9.33675 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Focal length 
                 14.4919 
                 44.3151 
                 135.3070 
               
               
                   
                 F-number 
                 4.00318 
                 5.40622 
                 5.99766 
               
               
                   
                 View angle 
                 39.8611 
                 13.7123 
                 4.5845 
               
               
                   
                 Image height 
                 10.8150 
                 10.8150 
                 10.8150 
               
               
                   
                 Overall length of lens 
                 101.9455 
                 132.7027 
                 162.8905 
               
               
                   
                 system 
                   
                   
                   
               
               
                   
                 BF 
                 2.80549 
                 2.83204 
                 2.87020 
               
               
                   
                 d5 
                 0.6596 
                 22.5410 
                 41.6141 
               
               
                   
                 d12 
                 2.8371 
                 3.0868 
                 6.1035 
               
               
                   
                 d14 
                 18.4343 
                 8.8238 
                 2.7427 
               
               
                   
                 d32 
                 9.4488 
                 27.6589 
                 41.7998 
               
               
                   
                 Entrance pupil position 
                 25.3181 
                 78.7228 
                 223.8111 
               
               
                   
                 Exit pupil position 
                 −37.3774 
                 −55.5875 
                 −69.7284 
               
               
                   
                 Front principal point 
                 34.5835 
                 89.4220 
                 106.9372 
               
               
                   
                 position 
                   
                   
                   
               
               
                   
                 Back principal point 
                 87.4536 
                 88.3877 
                 27.5835 
               
               
                   
                 position 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 (Lens element data) 
               
            
           
           
               
               
               
            
               
                 Unit 
                 Initial surface No. 
                 Focal length 
               
               
                   
               
            
           
           
               
               
               
            
               
                 1 
                 1 
                 −134.0520 
               
               
                 2 
                 2 
                 96.7509 
               
               
                 3 
                 4 
                 96.4914 
               
               
                 4 
                 6 
                 −16.6778 
               
               
                 5 
                 9 
                 −37.8072 
               
               
                 6 
                 11 
                 21.1040 
               
               
                 7 
                 13 
                 −21.1522 
               
               
                 8 
                 16 
                 24.2899 
               
               
                 9 
                 18 
                 19.8043 
               
               
                 10 
                 19 
                 −14.1462 
               
               
                 11 
                 21 
                 21.7746 
               
               
                 12 
                 23 
                 14.9598 
               
               
                 13 
                 24 
                 −8.9085 
               
               
                 14 
                 26 
                 19.0411 
               
               
                 15 
                 27 
                 −24.4565 
               
               
                 16 
                 29 
                 −42.7154 
               
               
                 17 
                 31 
                 45.2638 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                 (Zoom lens unit data) 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Initial 
                   
                 Length of 
                 Front 
                   
               
               
                   
                 surface 
                 Focal 
                 lens 
                 principal 
                 Back principal 
               
               
                 Unit 
                 No. 
                 length 
                 unit 
                 point position 
                 point position 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 1 
                 1 
                 76.72300 
                 13.93340 
                 3.26962 
                 8.46360 
               
               
                 2 
                 6 
                 −46.93302 
                 12.60210 
                 −10.83666 
                 −15.28913 
               
               
                 3 
                 13 
                 −21.15218 
                 1.20040 
                 0.08717 
                 0.62478 
               
               
                 4 
                 15 
                 19.37772 
                 35.82430 
                 0.10418 
                 10.76940 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 (Zoom lens unit magnification) 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Initial 
                   
                   
                   
               
               
                 Unit 
                 surface No. 
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 1 
                 1 
                 0.00000 
                 0.00000 
                 0.00000 
               
               
                 2 
                 6 
                 −1.36049 
                 −3.72016 
                 7.26826 
               
               
                 3 
                 13 
                 0.12997 
                 0.07727 
                 −0.08852 
               
               
                 4 
                 15 
                 −1.06826 
                 −2.00938 
                 −2.74110 
               
               
                   
               
            
           
         
       
     
     Numerical Example 2 
     The zoom lens system of Numerical Example 2 corresponds to Embodiment 2 shown in  FIG. 4 . Data of the zoom lens system of Numerical Example 2, i.e., the surface data, the aspheric surface data, the various data, the lens element data, the zoom lens unit data, and the zoom lens unit magnification are shown in Tables 8, 9, 10, 11, 12, and 13, respectively. 
     
       
         
           
               
             
               
                 TABLE 8 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                   
                   
                   
               
               
                  1 
                 92.44320 
                 1.50040 
                 1.84666 
                 23.8 
               
               
                  2 
                 50.47000 
                 6.96430 
                 1.49700 
                 81.6 
               
               
                  3 
                 −847.86000 
                 0.15000 
                   
                   
               
               
                  4 
                 47.25220 
                 5.18030 
                 1.71300 
                 53.9 
               
               
                  5 
                 145.99490 
                 Variable 
                   
                   
               
               
                  6* 
                 76.11200 
                 0.10120 
                 1.51358 
                 51.6 
               
               
                  7 
                 53.78650 
                 1.10000 
                 1.88300 
                 40.8 
               
               
                  8 
                 11.89720 
                 6.31220 
                   
                   
               
               
                  9 
                 −19.99880 
                 0.83260 
                 1.88300 
                 40.8 
               
               
                 10 
                 −51.23580 
                 0.87230 
                   
                   
               
               
                 11 
                 31.55930 
                 3.41140 
                 1.94595 
                 18.0 
               
               
                 12 
                 −51.41040 
                 Variable 
                   
                   
               
               
                 13* 
                 −19.63500 
                 1.20060 
                 1.80470 
                 41.0 
               
               
                 14* 
                 130.38440 
                 Variable 
                   
                   
               
               
                 15(Diaphragm) 
                 ∞ 
                 0.84590 
                   
                   
               
               
                 16* 
                 23.66010 
                 3.04770 
                 1.69350 
                 53.2 
               
               
                 17* 
                 −55.50020 
                 2.53870 
                   
                   
               
               
                 18 
                 15.07960 
                 3.25040 
                 1.71300 
                 53.9 
               
               
                 19 
                 −200.13220 
                 0.81020 
                 2.00069 
                 25.5 
               
               
                 20 
                 15.26060 
                 1.91230 
                   
                   
               
               
                 21 
                 31.28720 
                 5.87150 
                 1.59201 
                 67.0 
               
               
                 22* 
                 −20.38280 
                 0.89910 
                   
                   
               
               
                 23 
                 88.69790 
                 2.96860 
                 1.80518 
                 25.5 
               
               
                 24 
                 −13.74920 
                 0.80050 
                 1.83481 
                 42.7 
               
               
                 25 
                 16.65470 
                 2.35520 
                   
                   
               
               
                 26 
                 23.28540 
                 4.19220 
                 1.49700 
                 81.6 
               
               
                 27 
                 −15.00380 
                 0.80660 
                 1.83481 
                 42.7 
               
               
                 28 
                 −57.73780 
                 1.34160 
                   
                   
               
               
                 29 
                 −14.16980 
                 0.82280 
                 1.72916 
                 54.7 
               
               
                 30 
                 −26.59680 
                 0.14240 
                   
                   
               
               
                 31 
                 32.16560 
                 3.16330 
                 1.51680 
                 64.2 
               
               
                 32 
                 −83.11460 
                 Variable 
                   
                   
               
               
                 33 
                 ∞ 
                 4.20000 
                 1.51680 
                 64.2 
               
               
                 34 
                 ∞ 
                 BF 
                   
                   
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 9 
               
             
            
               
                   
               
               
                 (Aspherical data) 
               
            
           
           
               
               
            
               
                 Sur- 
                   
               
               
                 face 
                   
               
               
                 No. 
                 Parameters 
               
               
                   
               
               
                  6 
                 K = −8.65420E−01, A4 = 2.71985E−05, A6 = −1.27416E−08, 
               
               
                   
                 A8 = −8.47671E−10, A10 = 5.59117E−12, A12 = −1.03453E−14 
               
               
                 13 
                 K = 0.00000E+00, A4 = −3.92219E−05, A6 = 1.79165E−06, 
               
               
                   
                 A8 = −3.13018E−08, A10 = 1.39699E−10, A12 = 2.24266E−12 
               
               
                 14 
                 K = 5.23028E−01, A4 = −4.45154E−05, A6 = 2.19210E−06, 
               
               
                   
                 A8 = −5.22781E−08, A10 = 5.16605E−10, A12 = −1.29893E−13 
               
               
                 16 
                 K = 0.00000E+00, A4 = −1.12931E−05, A6 = 1.40885E−07, 
               
               
                   
                 A8 = −2.71412E−09, A10 = −7.20168E−11, A12 = −9.67929E−15 
               
               
                 17 
                 K = 0.00000E+00, A4 = 2.44916E−05, A6 = −3.83424E−08, 
               
               
                   
                 A8 = 1.18545E−09, A10 = −1.10236E−10, A12 = 9.17521E−15 
               
               
                 22 
                 K = 4.76603E−05, A4 = 1.81709E−05, A6 = −5.78282E−08, 
               
               
                   
                 A8 = 6.49528E−09, A10 = −6.93375E−11, A12 = 0.00000E+00 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 10 
               
             
            
               
                   
               
               
                 (Various data) 
               
               
                 Zooming ratio 9.35820 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Focal length 
                 14.4939 
                 44.3129 
                 135.6373 
               
               
                   
                 F-number 
                 4.00335 
                 5.40554 
                 5.99765 
               
               
                   
                 View angle 
                 39.9177 
                 13.7265 
                 4.5757 
               
               
                   
                 Image height 
                 10.8150 
                 10.8150 
                 10.8150 
               
               
                   
                 Overall length of lens 
                 101.6672 
                 132.4129 
                 161.5468 
               
               
                   
                 system 
                   
                   
                   
               
               
                   
                 BF 
                 2.80409 
                 2.82823 
                 2.86170 
               
               
                   
                 d5 
                 0.6595 
                 22.4493 
                 41.6494 
               
               
                   
                 d12 
                 2.6575 
                 3.0940 
                 6.3380 
               
               
                   
                 d14 
                 18.4611 
                 8.8422 
                 2.7298 
               
               
                   
                 d32 
                 9.4907 
                 27.6049 
                 40.3736 
               
               
                   
                 Entrance pupil position 
                 25.1796 
                 78.8630 
                 230.4632 
               
               
                   
                 Exit pupil position 
                 −37.4743 
                 −55.5885 
                 −68.3572 
               
               
                   
                 Front principal point 
                 34.4580 
                 89.5616 
                 107.7774 
               
               
                   
                 position 
                   
                   
                   
               
               
                   
                 Back principal point 
                 87.1732 
                 88.1000 
                 25.9095 
               
               
                   
                 position 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 11 
               
             
            
               
                   
               
               
                 (Lens element data) 
               
            
           
           
               
               
               
            
               
                 Unit 
                 Initial surface No. 
                 Focal length 
               
               
                   
               
            
           
           
               
               
               
            
               
                 1 
                 1 
                 −133.4756 
               
               
                 2 
                 2 
                 96.0920 
               
               
                 3 
                 4 
                 95.8923 
               
               
                 4 
                 6 
                 −16.6715 
               
               
                 5 
                 9 
                 −37.6192 
               
               
                 6 
                 11 
                 21.0941 
               
               
                 7 
                 13 
                 −21.1314 
               
               
                 8 
                 16 
                 24.3029 
               
               
                 9 
                 18 
                 19.7920 
               
               
                 10 
                 19 
                 −14.1429 
               
               
                 11 
                 21 
                 21.7676 
               
               
                 12 
                 23 
                 14.9778 
               
               
                 13 
                 24 
                 −8.9151 
               
               
                 14 
                 26 
                 19.0518 
               
               
                 15 
                 27 
                 −24.4932 
               
               
                 16 
                 29 
                 −42.7860 
               
               
                 17 
                 31 
                 45.2974 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 12 
               
             
            
               
                   
               
               
                 (Zoom lens unit data) 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Initial 
                   
                 Length of 
                 Front 
                   
               
               
                   
                 surface 
                 Focal 
                 lens 
                 principal 
                 Back principal 
               
               
                 Unit 
                 No. 
                 length 
                 unit 
                 point position 
                 point position 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 1 
                 1 
                 76.12978 
                 13.79500 
                 3.16804 
                 8.32000 
               
               
                 2 
                 6 
                 −46.72192 
                 12.62970 
                 −10.78714 
                 −15.22577 
               
               
                 3 
                 13 
                 −21.13139 
                 1.20060 
                 0.08676 
                 0.62446 
               
               
                 4 
                 15 
                 19.40387 
                 35.76900 
                 0.15790 
                 10.71360 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 13 
               
             
            
               
                   
               
               
                 (Zoom lens unit magnification) 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Initial 
                   
                   
                   
               
               
                 Unit 
                 surface No. 
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 1 
                 1 
                 0.00000 
                 0.00000 
                 0.00000 
               
               
                 2 
                 6 
                 −1.37173 
                 −3.80760 
                 6.74257 
               
               
                 3 
                 13 
                 0.13000 
                 0.07635 
                 −0.09926 
               
               
                 4 
                 15 
                 −1.06759 
                 −2.00237 
                 −2.66214 
               
               
                   
               
            
           
         
       
     
     Numerical Example 3 
     The zoom lens system of Numerical Example 3 corresponds to Embodiment 3 shown in  FIG. 7 . Data of the zoom lens system of Numerical Example 3, i.e., the surface data, the aspheric surface data, the various data, the lens element data, the zoom lens unit data, and the zoom lens unit magnification are shown in Tables 14, 15, 16, 17, 18, and 19. 
     
       
         
           
               
             
               
                 TABLE 14 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                   
                   
                   
               
               
                  1 
                 92.18470 
                 1.50890 
                 1.84666 
                 23.8 
               
               
                  2 
                 50.59720 
                 7.14140 
                 1.49700 
                 81.6 
               
               
                  3 
                 −966.46410 
                 0.15000 
                   
                   
               
               
                  4 
                 47.41520 
                 5.21930 
                 1.71300 
                 53.9 
               
               
                  5 
                 147.10900 
                 Variable 
                   
                   
               
               
                  6* 
                 76.06950 
                 0.10000 
                 1.51358 
                 51.6 
               
               
                  7 
                 53.68590 
                 1.10000 
                 1.88300 
                 40.8 
               
               
                  8 
                 11.89330 
                 6.30890 
                   
                   
               
               
                  9 
                 −20.09130 
                 0.82990 
                 1.88300 
                 40.8 
               
               
                 10 
                 −51.39420 
                 0.86980 
                   
                   
               
               
                 11 
                 31.43820 
                 3.39610 
                 1.94595 
                 18.0 
               
               
                 12 
                 −51.92400 
                 Variable 
                   
                   
               
               
                 13* 
                 −19.67220 
                 1.20030 
                 1.80470 
                 41.0 
               
               
                 14* 
                 130.03760 
                 Variable 
                   
                   
               
               
                 15(Diaphragm) 
                 ∞ 
                 0.84510 
                   
                   
               
               
                 16* 
                 23.65970 
                 3.08600 
                 1.69350 
                 53.2 
               
               
                 17* 
                 −55.55620 
                 2.52620 
                   
                   
               
               
                 18 
                 15.07550 
                 3.25020 
                 1.71300 
                 53.9 
               
               
                 19 
                 −200.60280 
                 0.81020 
                 2.00069 
                 25.5 
               
               
                 20 
                 15.26000 
                 1.91520 
                   
                   
               
               
                 21 
                 31.28380 
                 5.89510 
                 1.59201 
                 67.0 
               
               
                 22* 
                 −20.38310 
                 0.89970 
                   
                   
               
               
                 23 
                 88.64240 
                 2.96970 
                 1.80518 
                 25.5 
               
               
                 24 
                 −13.75430 
                 0.80000 
                 1.83481 
                 42.7 
               
               
                 25 
                 16.65230 
                 2.34540 
                   
                   
               
               
                 26 
                 23.28500 
                 4.18950 
                 1.49700 
                 81.6 
               
               
                 27 
                 −14.99040 
                 0.80000 
                 1.83481 
                 42.7 
               
               
                 28 
                 −57.73810 
                 1.34500 
                   
                   
               
               
                 29 
                 −14.15720 
                 0.80000 
                 1.72916 
                 54.7 
               
               
                 30 
                 −26.59940 
                 0.12110 
                   
                   
               
               
                 31 
                 32.21740 
                 3.16040 
                 1.51680 
                 64.2 
               
               
                 32 
                 −82.24800 
                 Variable 
                   
                   
               
               
                 33 
                 ∞ 
                 4.20000 
                 1.51680 
                 64.2 
               
               
                 34 
                 ∞ 
                 BF 
                   
                   
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 15 
               
             
            
               
                   
               
               
                 (Aspheric surface data) 
               
            
           
           
               
               
            
               
                 Sur- 
                   
               
               
                 face 
                   
               
               
                 No. 
                 Parameters 
               
               
                   
               
               
                  6 
                 K = −9.10525E−01, A4 = 2.71853E−05, A6 = −1.17499E−08, 
               
               
                   
                 A8 = −8.46191E−10, A10 = 5.58176E−12, A12 = −1.05149E−14 
               
               
                 13 
                 K = 0.00000E+00, A4 = −3.91920E−05, A6 = 1.79159E−06, 
               
               
                   
                 A8 = −3.13204E−08, A10 = 1.39427E−10, A12 = 2.21441E−12 
               
               
                 14 
                 K = 2.72517E−01, A4 = −4.45295E−05, A6 = 2.19143E−06, 
               
               
                   
                 A8 = −5.22877E−08, A10 = 5.16656E−10, A12 = −5.67168E−14 
               
               
                 16 
                 K = 0.00000E+00, A4 = −1.12941E−05, A6 = 1.40911E−07, 
               
               
                   
                 A8 = −2.71164E−09, A10 = −7.19359E−11, A12 = −5.77241E−15 
               
               
                 17 
                 K = 0.00000E+00, A4 = 2.44934E−05, A6 = −3.84036E−08, 
               
               
                   
                 A8 = 1.18226E−09, A10 = −1.10332E−10, A12 = 5.60567E−15 
               
               
                 22 
                 K = 0.00000E+00, A4 = 1.81820E−05, A6 = −5.77336E−08, 
               
               
                   
                 A8 = 6.49279E−09, A10 = −6.93404E−11, A12 = 0.00000E+00 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 16 
               
             
            
               
                   
               
               
                 (Various data) 
               
               
                 Zooming ratio 9.33034 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Focal length 
                 14.5015 
                 44.3144 
                 135.3042 
               
               
                   
                 F-number 
                 4.00344 
                 5.40547 
                 5.99782 
               
               
                   
                 View angle 
                 39.8346 
                 13.7288 
                 4.5866 
               
               
                   
                 Image height 
                 10.8150 
                 10.8150 
                 10.8150 
               
               
                   
                 Overall length of lens 
                 101.9638 
                 132.5433 
                 161.6026 
               
               
                   
                 system 
                   
                   
                   
               
               
                   
                 BF 
                 2.80190 
                 2.83011 
                 2.85362 
               
               
                   
                 d5 
                 0.6873 
                 22.4396 
                 41.7186 
               
               
                   
                 d12 
                 2.7417 
                 3.0466 
                 6.0472 
               
               
                   
                 d14 
                 18.4749 
                 8.8416 
                 2.7452 
               
               
                   
                 d32 
                 9.4746 
                 27.6020 
                 40.4546 
               
               
                   
                 Entrance pupil position 
                 25.4494 
                 78.8584 
                 228.9072 
               
               
                   
                 Exit pupil position 
                 −37.3528 
                 −55.4802 
                 −68.3328 
               
               
                   
                 Front principal point 
                 34.7139 
                 89.4949 
                 107.0383 
               
               
                   
                 position 
                   
                   
                   
               
               
                   
                 Back principal point 
                 87.4623 
                 88.2289 
                 26.2984 
               
               
                   
                 position 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 17 
               
             
            
               
                   
               
               
                 (Lens element data) 
               
            
           
           
               
               
               
            
               
                 Unit 
                 Initial surface No. 
                 Focal length 
               
               
                   
               
            
           
           
               
               
               
            
               
                 1 
                 1 
                 −134.7090 
               
               
                 2 
                 2 
                 96.9672 
               
               
                 3 
                 4 
                 96.0367 
               
               
                 4 
                 6 
                 −16.6695 
               
               
                 5 
                 9 
                 −37.8277 
               
               
                 6 
                 11 
                 21.1192 
               
               
                 7 
                 13 
                 −21.1586 
               
               
                 8 
                 16 
                 24.3146 
               
               
                 9 
                 18 
                 19.7900 
               
               
                 10 
                 19 
                 −14.1448 
               
               
                 11 
                 21 
                 21.7708 
               
               
                 12 
                 23 
                 14.9815 
               
               
                 13 
                 24 
                 −8.9164 
               
               
                 14 
                 26 
                 19.0411 
               
               
                 15 
                 27 
                 −24.4618 
               
               
                 16 
                 29 
                 −42.6645 
               
               
                 17 
                 31 
                 45.2195 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 18 
               
             
            
               
                   
               
               
                 (Zoom lens unit data) 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Initial 
                   
                 Length of 
                 Front 
                   
               
               
                   
                 surface 
                 Focal 
                 lens 
                 principal 
                 Back principal 
               
               
                 Unit 
                 No. 
                 length 
                 unit 
                 point position 
                 point position 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 1 
                 1 
                 76.41416 
                 14.01960 
                 3.24460 
                 8.47258 
               
               
                 2 
                 6 
                 −46.76258 
                 12.60470 
                 −10.77426 
                 −15.18802 
               
               
                 3 
                 13 
                 −21.15864 
                 1.20030 
                 0.08708 
                 0.62466 
               
               
                 4 
                 15 
                 19.38243 
                 35.75880 
                 0.11636 
                 10.76666 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 19 
               
             
            
               
                   
               
               
                 (Zoom lens unit magnification) 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Initial 
                   
                   
                   
               
               
                 Unit 
                 surface No. 
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 1 
                 1 
                 0.00000 
                 0.00000 
                 0.00000 
               
               
                 2 
                 6 
                 −1.36767 
                 −3.75928 
                 6.83686 
               
               
                 3 
                 13 
                 0.13021 
                 0.07704 
                 −0.09712 
               
               
                 4 
                 15 
                 −1.06567 
                 −2.00237 
                 −2.66669 
               
               
                   
               
            
           
         
       
     
     Numerical Example 4 
     The zoom lens system of Numerical Example 4 corresponds to Embodiment 4 shown in  FIG. 10 . Data of the zoom lens system of Numerical Example 4, i.e., the surface data, the aspheric surface data, the various data, the lens element data, the zoom lens unit data, and the zoom lens unit magnification are shown in Tables 20, 21, 22, 23, 24, and 25, respectively. 
     
       
         
           
               
             
               
                 TABLE 20 
               
             
            
               
                   
               
               
                 (surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                   
                   
                   
               
               
                  1 
                 90.30820 
                 1.93190 
                 1.84666 
                 23.8 
               
               
                  2 
                 50.87660 
                 7.33030 
                 1.49700 
                 81.6 
               
               
                  3 
                 −922.88540 
                 0.15000 
                   
                   
               
               
                  4 
                 48.34930 
                 4.89480 
                 1.71700 
                 47.9 
               
               
                  5 
                 147.06100 
                 Variable 
                   
                   
               
               
                  6* 
                 58.12980 
                 1.20000 
                 1.90681 
                 21.2 
               
               
                  7 
                 11.31120 
                 6.28100 
                   
                   
               
               
                  8 
                 −19.38970 
                 0.89450 
                 1.88300 
                 40.8 
               
               
                  9 
                 −64.19440 
                 0.91900 
                   
                   
               
               
                 10 
                 30.72250 
                 3.72760 
                 1.94595 
                 18.0 
               
               
                 11 
                 −33.35260 
                 Variable 
                   
                   
               
               
                 12* 
                 −18.28890 
                 1.20110 
                 1.80420 
                 46.5 
               
               
                 13* 
                 109.11350 
                 Variable 
                   
                   
               
               
                 14(Diaphragm) 
                 ∞ 
                 0.80610 
                   
                   
               
               
                 15* 
                 23.54260 
                 2.43820 
                 1.69350 
                 53.2 
               
               
                 16* 
                 −52.76110 
                 5.60730 
                   
                   
               
               
                 17 
                 15.34600 
                 3.22520 
                 1.71300 
                 53.9 
               
               
                 18 
                 −197.48210 
                 0.80880 
                 2.00069 
                 25.5 
               
               
                 19 
                 15.25880 
                 1.47090 
                   
                   
               
               
                 20 
                 26.90540 
                 3.11630 
                 1.59201 
                 67.0 
               
               
                 21* 
                 −22.34970 
                 0.87140 
                   
                   
               
               
                 22 
                 97.11210 
                 3.05020 
                 1.80518 
                 25.5 
               
               
                 23 
                 −15.86630 
                 0.80000 
                 1.83481 
                 42.7 
               
               
                 24 
                 16.64980 
                 1.87130 
                   
                   
               
               
                 25 
                 23.47560 
                 4.44630 
                 1.49700 
                 81.6 
               
               
                 26 
                 −14.64800 
                 0.80000 
                 1.83481 
                 42.7 
               
               
                 27 
                 −60.20220 
                 1.24930 
                   
                   
               
               
                 28 
                 −17.34570 
                 0.80000 
                 1.72916 
                 54.7 
               
               
                 29 
                 −39.86110 
                 0.28520 
                   
                   
               
               
                 30 
                 33.25040 
                 2.68470 
                 1.51680 
                 64.2 
               
               
                 31 
                 −73.57350 
                 Variable 
                   
                   
               
               
                 32 
                 ∞ 
                 4.20000 
                 1.51680 
                 64.2 
               
               
                 33 
                 ∞ 
                 BF 
                   
                   
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 21 
               
             
            
               
                   
               
               
                 (aspherical data) 
               
            
           
           
               
               
            
               
                 Sur- 
                   
               
               
                 face 
                   
               
               
                 No. 
                 Parameters 
               
               
                   
               
               
                  6 
                 K = −1.96414E+01, A4 = 2.17865E−05, A6 = −7.11149E−08, 
               
               
                   
                 A8 = −4.34378E−10, A10 = 4.69717E−12, A12 = −1.54970E−14 
               
               
                 12 
                 K = 0.00000E+00, A4 = −2.79093E−05, A6 = 2.00080E−06, 
               
               
                   
                 A8 = −2.37691E−08, A10 = 1.26736E−11, A12 = 9.26223E−13 
               
               
                 13 
                 K = 5.35969E+01, A4 = −4.04231E−05, A6 = 2.44155E−06, 
               
               
                   
                 A8 = −5.15800E−08, A10 = 5.92811E−10, A12 = −2.81121E−12 
               
               
                 15 
                 K = 0.00000E+00, A4 = −6.06935E−06, A6 = 3.73242E−08, 
               
               
                   
                 A8 = −3.05202E−09, A10 = −7.46214E−11, A12 = −3.43954E−13 
               
               
                 16 
                 K = 0.00000E+00, A4 = 2.56389E−05, A6 = −7.24066E−08, 
               
               
                   
                 A8 = −4.48824E−10, A10 = −1.28984E−10, A12 = 6.18123E−15 
               
               
                 21 
                 K = 0.00000E+00, A4 = 2.54758E−05, A6 = 9.61906E−08, 
               
               
                   
                 A8 = 7.43701E−10, A10 = −3.39306E−13, A12 = 0.00000E+00 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 22 
               
             
            
               
                   
               
               
                 (various data) 
               
               
                 Zooming ratio 9.50927 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Focal length 
                 14.5133 
                 44.3163 
                 138.0113 
               
               
                   
                 F-number 
                 4.05105 
                 5.51642 
                 6.29179 
               
               
                   
                 View angle 
                 40.2948 
                 13.6070 
                 4.4736 
               
               
                   
                 Image height 
                 10.8150 
                 10.8150 
                 10.8150 
               
               
                   
                 Overall length of lens 
                 101.9105 
                 133.8869 
                 163.2443 
               
               
                   
                 system 
                   
                   
                   
               
               
                   
                 BF 
                 2.79643 
                 2.82858 
                 2.86373 
               
               
                   
                 d5 
                 0.6599 
                 22.4056 
                 41.2644 
               
               
                   
                 d11 
                 3.5868 
                 5.1902 
                 7.2600 
               
               
                   
                 d13 
                 18.1884 
                 8.8136 
                 2.7095 
               
               
                   
                 d31 
                 9.6176 
                 27.5875 
                 42.0853 
               
               
                   
                 Entrance pupil position 
                 25.5492 
                 80.6266 
                 224.4799 
               
               
                   
                 Exit pupil position 
                 −36.1526 
                 −54.1225 
                 −68.6203 
               
               
                   
                 Front principal point 
                 34.6545 
                 90.4583 
                 96.0385 
               
               
                   
                 position 
                   
                   
                   
               
               
                   
                 Back principal point 
                 87.3972 
                 89.5705 
                 25.2330 
               
               
                   
                 position 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 23 
               
             
            
               
                   
               
               
                 (lens element data) 
               
            
           
           
               
               
               
            
               
                 Unit 
                 Initial surface No. 
                 Focal length 
               
               
                   
               
            
           
           
               
               
               
            
               
                 1 
                 1 
                 −140.7850 
               
               
                 2 
                 2 
                 97.2626 
               
               
                 3 
                 4 
                 98.4231 
               
               
                 4 
                 6 
                 −15.6783 
               
               
                 5 
                 8 
                 −31.7592 
               
               
                 6 
                 10 
                 17.3976 
               
               
                 7 
                 12 
                 −19.3956 
               
               
                 8 
                 15 
                 23.7846 
               
               
                 9 
                 17 
                 20.0980 
               
               
                 10 
                 18 
                 −14.1277 
               
               
                 11 
                 20 
                 21.1187 
               
               
                 12 
                 22 
                 17.1444 
               
               
                 13 
                 23 
                 −9.6242 
               
               
                 14 
                 25 
                 18.8798 
               
               
                 15 
                 26 
                 −23.3754 
               
               
                 16 
                 28 
                 −42.7558 
               
               
                 17 
                 30 
                 44.6955 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 24 
               
             
            
               
                   
               
               
                 (Zoom lens unit data) 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Initial 
                   
                 Length of 
                 Front 
                   
               
               
                   
                 surface 
                 Focal 
                 lens 
                 principal 
                 Back principal 
               
               
                 Unit 
                 No. 
                 length 
                 unit 
                 point position 
                 point position 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 1 
                 1 
                 76.52671 
                 14.30700 
                 3.39343 
                 8.72110 
               
               
                 2 
                 6 
                 −81.54993 
                 13.02210 
                 −25.94425 
                 −41.08891 
               
               
                 3 
                 12 
                 −19.39560 
                 1.20110 
                 0.09517 
                 0.63333 
               
               
                 4 
                 14 
                 19.08890 
                 34.33120 
                 −0.71921 
                 9.87207 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 25 
               
             
            
               
                   
               
               
                 (zoom lens unit magnification) 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Initial 
                   
                   
                   
               
               
                 Unit 
                 surface No. 
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 1 
                 1 
                 0.00000 
                 0.00000 
                 0.00000 
               
               
                 2 
                 6 
                 −5.55698 
                 11.53388 
                 3.14509 
               
               
                 3 
                 12 
                 0.03170 
                 −0.02486 
                 −0.20618 
               
               
                 4 
                 14 
                 −1.07671 
                 −2.01978 
                 −2.78111 
               
               
                   
               
            
           
         
       
     
     Numerical Example 5 
     The zoom lens system of Numerical Example 5 corresponds to Embodiment 5 shown in  FIG. 13 . Data of the zoom lens system of Numerical Example 5, i.e., the surface data, the aspheric surface data, the various data, the lens element data, the zoom lens unit data, and the zoom lens unit magnification are shown in Tables 26, 27, 28, 29, 30, and 31, respectively. 
     
       
         
           
               
             
               
                 TABLE 26 
               
             
            
               
                   
               
               
                 (surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                   
                   
                   
               
               
                  1 
                 78.05430 
                 1.50000 
                 1.84666 
                 23.8 
               
               
                  2 
                 47.86090 
                 7.82000 
                 1.49700 
                 81.6 
               
               
                  3 
                 −2811.69830 
                 0.15000 
                   
                   
               
               
                  4 
                 45.22120 
                 5.58000 
                 1.58913 
                 61.3 
               
               
                  5 
                 159.80500 
                 Variable 
                   
                   
               
               
                  6* 
                 76.22710 
                 1.50000 
                 1.80610 
                 40.7 
               
               
                  7 
                 11.48720 
                 6.49850 
                   
                   
               
               
                  8 
                 −25.34440 
                 0.80000 
                 1.80420 
                 46.5 
               
               
                  9 
                 −144.44850 
                 0.27270 
                   
                   
               
               
                 10 
                 26.87530 
                 3.55000 
                 1.94595 
                 18.0 
               
               
                 11 
                 −79.37890 
                 Variable 
                   
                   
               
               
                 12* 
                 −22.52260 
                 1.10000 
                 1.80610 
                 40.7 
               
               
                 13* 
                 111.65510 
                 Variable 
                   
                   
               
               
                 14(Diaphragm) 
                 ∞ 
                 0.90030 
                   
                   
               
               
                 15* 
                 15.72440 
                 3.34000 
                 1.69350 
                 53.2 
               
               
                 16* 
                 −97.79480 
                 0.53570 
                   
                   
               
               
                 17 
                 15.91670 
                 2.60000 
                 1.69962 
                 55.3 
               
               
                 18 
                 121.55860 
                 0.70000 
                 2.00069 
                 25.5 
               
               
                 19 
                 13.58960 
                 1.13010 
                   
                   
               
               
                 20 
                 39.58830 
                 3.88000 
                 1.49700 
                 81.6 
               
               
                 21 
                 −16.97330 
                 1.56860 
                   
                   
               
               
                 22 
                 271.67740 
                 3.45000 
                 1.84666 
                 23.8 
               
               
                 23 
                 −14.95720 
                 0.70000 
                 1.83481 
                 42.7 
               
               
                 24 
                 17.34190 
                 2.52590 
                   
                   
               
               
                 25 
                 52.65190 
                 2.63000 
                 1.49700 
                 81.6 
               
               
                 26 
                 −63.47340 
                 1.59420 
                   
                   
               
               
                 27 
                 −14.34770 
                 1.10000 
                 1.80610 
                 40.7 
               
               
                 28* 
                 −25.33540 
                 0.15000 
                   
                   
               
               
                 29 
                 21.81500 
                 5.47000 
                 1.49700 
                 81.6 
               
               
                 30 
                 −19.40750 
                 0.70000 
                 1.77250 
                 49.6 
               
               
                 31 
                 −49.40210 
                 Variable 
                   
                   
               
               
                 32 
                 ∞ 
                 4.20000 
                 1.51680 
                 64.2 
               
               
                 33 
                 ∞ 
                 BF 
                   
                   
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 27 
               
             
            
               
                   
               
               
                 (aspherical data) 
               
            
           
           
               
               
            
               
                 Sur- 
                   
               
               
                 face 
                   
               
               
                 No. 
                 Parameters 
               
               
                   
               
               
                  6 
                 K = 0.00000E+00, A4 = 1.29469E−05, A6 = −2.04795E−08, 
               
               
                   
                 A8 = −2.69870E−10, A10 = 1.82078E−12, A12 = −4.05694E−15 
               
               
                 12 
                 K = 0.00000E+00, A4 = −5.27193E−05, A6 = 1.84470E−06, 
               
               
                   
                 A8 = −2.69590E−08, A10 = 2.09790E−10, A12 = −3.43788E−13 
               
               
                 13 
                 K = 0.000000E+00, A4 = −4.85338E−05, A6 = 1.64899E−06, 
               
               
                   
                 A8 = −2.62063E−08, A10 = 2.03012E−10, A12 = 0.00000E+00 
               
               
                 15 
                 K = 0.00000E+00, A4 = −1.30370E−06, A6 = 1.15937E−07, 
               
               
                   
                 A8 = 1.23700E−09, A10 = 1.54415E−10, A12 = 0.00000E+00 
               
               
                 16 
                 K = 0.00000E+00, A4 = 7.66841E−05, A6 = 1.11210E−07, 
               
               
                   
                 A8 = 2.03485E−09, A10 = 1.99005E−10, A12 = 0.00000E+00 
               
               
                 28 
                 K = 0.00000E+00, A4 = −1.11851E−07, A6 = 1.14428E−06, 
               
               
                   
                 A8 = −5.01498E−08, A10 = 1.16520E−09, A12 = −1.00877E−11 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 28 
               
             
            
               
                   
               
               
                 (various data) 
               
               
                 Zooming ratio 9.27842 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Focal length 
                 14.5708 
                 44.3848 
                 135.1938 
               
               
                   
                 F-number 
                 4.16329 
                 4.96539 
                 5.82732 
               
               
                   
                 View angle 
                 38.9333 
                 13.4967 
                 4.5019 
               
               
                   
                 Image height 
                 10.6150 
                 10.6150 
                 10.6150 
               
               
                   
                 Overall length of lens 
                 101.9979 
                 130.1011 
                 158.9982 
               
               
                   
                 system 
                   
                   
                   
               
               
                   
                 BF 
                 2.77797 
                 2.84202 
                 2.81725 
               
               
                   
                 d5 
                 0.7000 
                 21.5452 
                 40.0030 
               
               
                   
                 d11 
                 2.9897 
                 3.4834 
                 7.0416 
               
               
                   
                 d13 
                 20.1533 
                 9.3395 
                 2.4926 
               
               
                   
                 d31 
                 9.4309 
                 26.9450 
                 40.6978 
               
               
                   
                 Entrance pupil position 
                 28.3323 
                 81.6514 
                 226.3810 
               
               
                   
                 Exit pupil position 
                 −37.7892 
                 −55.3033 
                 −69.0561 
               
               
                   
                 Front principal point 
                 37.6696 
                 92.1553 
                 107.2749 
               
               
                   
                 position 
                   
                   
                   
               
               
                   
                 Back principal point 
                 87.4271 
                 85.7163 
                 23.8044 
               
               
                   
                 position 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 29 
               
             
            
               
                   
               
               
                 (lens element data) 
               
            
           
           
               
               
               
            
               
                 Unit 
                 Initial surface No. 
                 Focal length 
               
               
                   
               
            
           
           
               
               
               
            
               
                 1 
                 1 
                 −149.5413 
               
               
                 2 
                 2 
                 94.7744 
               
               
                 3 
                 4 
                 105.1546 
               
               
                 4 
                 6 
                 −16.9542 
               
               
                 5 
                 8 
                 −38.3360 
               
               
                 6 
                 10 
                 21.5753 
               
               
                 7 
                 12 
                 −23.1655 
               
               
                 8 
                 15 
                 19.7714 
               
               
                 9 
                 17 
                 25.9156 
               
               
                 10 
                 18 
                 −15.3392 
               
               
                 11 
                 20 
                 24.4603 
               
               
                 12 
                 22 
                 16.8371 
               
               
                 13 
                 23 
                 −9.5259 
               
               
                 14 
                 25 
                 58.3449 
               
               
                 15 
                 27 
                 −42.9602 
               
               
                 16 
                 29 
                 21.6174 
               
               
                 17 
                 30 
                 −41.8036 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 30 
               
             
            
               
                   
               
               
                 (Zoom lens unit data) 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Initial 
                   
                 Length of 
                 Front 
                   
               
               
                   
                 surface 
                 Focal 
                 lens 
                 principal 
                 Back principal 
               
               
                 Unit 
                 No. 
                 length 
                 unit 
                 point position 
                 point position 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 1 
                 1 
                 76.52351 
                 15.05000 
                 3.15738 
                 8.47428 
               
               
                 2 
                 6 
                 −39.03253 
                 12.62120 
                 −6.65518 
                 −7.89966 
               
               
                 3 
                 12 
                 −23.16550 
                 1.10000 
                 0.10186 
                 0.59503 
               
               
                 4 
                 14 
                 20.03471 
                 32.97480 
                 0.72903 
                 8.14210 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 31 
               
             
            
               
                   
               
               
                 (zoom lens unit magnification) 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Initial 
                   
                   
                   
               
               
                 Unit 
                 surface No. 
                 Wide 
                 Middle 
                 Telephoto 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 1 
                 1 
                 0.00000 
                 0.00000 
                 0.00000 
               
               
                 2 
                 6 
                 −1.05864 
                 −2.43569 
                 16.04584 
               
               
                 3 
                 12 
                 0.18222 
                 0.12772 
                 −0.04318 
               
               
                 4 
                 14 
                 −0.98708 
                 −1.86446 
                 −2.54968 
               
               
                   
               
            
           
         
       
     
     The following Table 32 show values corresponding to the individual conditions in the zoom lens systems of the respective numerical examples. 
     
       
         
           
               
             
               
                 TABLE 32 
               
             
            
               
                   
               
               
                 (corresponding values to individual conditions: Numerical 
               
               
                 Examples 1 to 5) 
               
            
           
           
               
               
            
               
                   
                 Numerical Example 
               
            
           
           
               
               
               
               
               
               
            
               
                 Condition 
                 1 
                 2 
                 3 
                 4 
                 5 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 (1) 
                 f 4A /f 4α   
                 0.86 
                 0.86 
                 0.86 
                 0.87 
                 0.79 
               
               
                 (2) 
                 f 4Ob /f 4α   
                 0.86 
                 0.86 
                 0.86 
                 0.87 
                 0.79 
               
               
                 (3) 
                 f 4B /f 4α   
                 −1.22 
                 −1.22 
                 −1.22 
                 −1.22 
                 −1.14 
               
               
                 (4) 
                 f 4Im /f 4α   
                 4.03 
                 4.00 
                 4.02 
                 4.38 
                 2.75 
               
               
                 (5) 
                 f 4α /f W   
                 1.34 
                 1.34 
                 1.34 
                 1.32 
                 1.38 
               
               
                 (6) 
                 f F /f 4α   
                 −1.09 
                 −1.09 
                 −1.09 
                 −1.02 
                 −1.16 
               
               
                 (7) 
                 f 1  * (f T /f W )/ 
                 16.19 
                 16.07 
                 16.10 
                 16.27 
                 16.01 
               
               
                   
                 {square root over ((f W  * f T ))} 
                   
                   
                   
                   
                   
               
               
                 (8) 
                 f 2  * (f T /f W )/ 
                 −9.90 
                 −9.86 
                 −9.86 
                 −17.34 
                 −8.16 
               
               
                   
                 {square root over ((f W  * f T ))} 
                   
                   
                   
                   
                   
               
               
                 (9) 
                 δt 1 /f 1   
                 0.79 
                 0.79 
                 0.78 
                 0.80 
                 0.74 
               
               
                 (10) 
                 δt 2 /f 2   
                 −0.42 
                 −0.40 
                 −0.40 
                 −0.25 
                 −0.45 
               
               
                 (11) 
                 δt 3 /f 3   
                 −0.79 
                 −0.72 
                 −0.72 
                 −0.88 
                 −0.59 
               
               
                 (12) 
                 δt 4 /f 4   
                 1.67 
                 1.59 
                 1.60 
                 1.70 
                 1.56 
               
               
                 (13) 
                 β 2T /β 2W   
                 −5.34 
                 −4.91 
                 −5.00 
                 −0.57 
                 −15.15 
               
               
                 (14) 
                 β 3T /β 3W   
                 −0.68 
                 −0.76 
                 −0.75 
                 −6.44 
                 −0.24 
               
               
                 (15) 
                 β 4T /β 4W   
                 2.57 
                 2.49 
                 2.50 
                 2.58 
                 2.58 
               
               
                 (16) 
                 f 3  * β 3W  * β 3W / 
                 6.21 
                 6.09 
                 5.99 
                 −0.09 
                 5.33 
               
               
                   
                 (δ S3  * f T /f W ) 
                   
                   
                   
                   
                   
               
               
                 (17) 
                 DIS W  * f T /f W   
                 −1.02 
                 −1.03 
                 −1.02 
                 −1.14 
                 −0.93 
               
               
                 (18) 
                 nd 2   
                 1.904 
                 1.904 
                 1.904 
                 1.912 
                 1.852 
               
               
                   
               
            
           
         
       
     
     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. 
     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.