Patent Publication Number: US-9417430-B2

Title: Inner focus lens system, interchangeable lens apparatus and camera system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based on application No. 2012-161185 filed in Japan on Jul. 20, 2012 and application No. 2013-099293 filed in Japan on May 9, 2013, the contents of which are hereby incorporated by reference. 
     BACKGROUND 
     1. Field 
     The present disclosure relates to inner focus lens systems, interchangeable lens apparatuses and camera systems. 
     2. Description of the Related Art 
     In interchangeable lens apparatuses, camera systems, and the like, size reduction and performance improvement are strongly required of cameras each including an image sensor for performing photoelectric conversion. Various kinds of lens systems used in such cameras have been proposed. 
     Japanese Laid-Open Patent Publications Nos. H01-237611, H07-301749, 2005-292345, 2009-288384, and 2012-058682 each disclose an inner focus lens system including: a first lens unit having positive refractive power, which is fixed with respect to an image surface in focusing from an infinity in-focus condition to a close-object in-focus condition; and subsequent lens units. 
     SUMMARY 
     The present disclosure provides a compact inner focus lens system having high resolution and excellent performance, in which occurrences of various aberrations are sufficiently suppressed. Further, the present disclosure provides an interchangeable lens apparatus including the inner focus lens system, and a camera system including the interchangeable lens apparatus. 
     (I) The novel concepts disclosed herein were achieved in order to solve the foregoing problems in the related art, and herein is disclosed: 
     an inner focus lens system, in order from an object side to an image side, comprising a first lens unit, and subsequent lens units, wherein 
     the first lens unit is fixed with respect to an image surface in focusing from an infinity in-focus condition to a close-object in-focus condition, 
     the first lens unit includes: a first positive lens element being located closest to the object side, and having positive optical power; and a second positive lens element having positive optical power, 
     the subsequent lens units include only a first focusing lens unit located closest to the object side, and a second focusing lens unit, as focusing lens units that move along an optical axis in the focusing, 
     at least one of the first focusing lens unit and the second focusing lens unit is composed of two or less lens elements, and 
     the subsequent lens units include an image blur compensating lens unit that moves in a direction perpendicular to the optical axis to optically compensate image blur. 
     The novel concepts disclosed herein were achieved in order to solve the foregoing problems in the related art, and herein is disclosed: 
     an interchangeable lens apparatus comprising: 
     an inner focus lens system; and 
     a lens mount section which is connectable to a camera body including an image sensor for receiving an optical image formed by the inner focus lens system and converting the optical image into an electric image signal, wherein 
     the inner focus lens system is an inner focus lens system, in order from an object side to an image side, comprising a first lens unit, and subsequent lens units, wherein 
     the first lens unit is fixed with respect to an image surface in focusing from an infinity in-focus condition to a close-object in-focus condition, 
     the first lens unit includes: a first positive lens element being located closest to the object side, and having positive optical power; and a second positive lens element having positive optical power, 
     the subsequent lens units include only a first focusing lens unit located closest to the object side, and a second focusing lens unit, as focusing lens units that move along an optical axis in the focusing, 
     at least one of the first focusing lens unit and the second focusing lens unit is composed of two or less lens elements, and 
     the subsequent lens units include an image blur compensating lens unit that moves in a direction perpendicular to the optical axis to optically compensate image blur. 
     The novel concepts disclosed herein were achieved in order to solve the foregoing problems in the related art, and herein is disclosed: 
     a camera system comprising: 
     an interchangeable lens apparatus including an inner focus lens system; and 
     a camera body which is detachably connected to the interchangeable lens apparatus via a camera mount section, and includes an image sensor for receiving an optical image formed by the inner focus lens system and converting the optical image into an electric image signal, wherein 
     the inner focus lens system is an inner focus lens system, in order from an object side to an image side, comprising a first lens unit, and subsequent lens units, wherein 
     the first lens unit is fixed with respect to an image surface in focusing from an infinity in-focus condition to a close-object in-focus condition, 
     the first lens unit includes: a first positive lens element being located closest to the object side, and having positive optical power; and a second positive lens element having positive optical power, 
     the subsequent lens units include only a first focusing lens unit located closest to the object side, and a second focusing lens unit, as focusing lens units that move along an optical axis in the focusing, 
     at least one of the first focusing lens unit and the second focusing lens unit is composed of two or less lens elements, and 
     the subsequent lens units include an image blur compensating lens unit that moves in a direction perpendicular to the optical axis to optically compensate image blur. 
     (II) The novel concepts disclosed herein were achieved in order to solve the foregoing problems in the related art, and herein is disclosed: 
     an inner focus lens system, in order from an object side to an image side, comprising a first lens unit, and subsequent lens units, wherein 
     the first lens unit is fixed with respect to an image surface in focusing from an infinity in-focus condition to a close-object in-focus condition, 
     the first lens unit includes: a first positive lens element being located closest to the object side, and having positive optical power; and a second positive lens element having positive optical power, 
     the subsequent lens units include at least a first focusing lens unit located closest to the object side, and a second focusing lens unit, as focusing lens units that move along an optical axis in the focusing, 
     the subsequent lens units include an image blur compensating lens unit that moves in a direction perpendicular to the optical axis to optically compensate image blur, and 
     the following condition (8) is satisfied:
 
 L   A   /f   A &lt;1.2 . . .  (8)
 
     where 
     L A  is an overall length of the inner focus lens system (a distance from an object side surface of the first positive lens element to the image surface), and 
     f A  is a focal length of the entire inner focus lens system. 
     The novel concepts disclosed herein were achieved in order to solve the foregoing problems in the related art, and herein is disclosed: 
     an interchangeable lens apparatus comprising: 
     an inner focus lens system; and 
     a lens mount section which is connectable to a camera body including an image sensor for receiving an optical image formed by the inner focus lens system and converting the optical image into an electric image signal, wherein 
     the inner focus lens system is an inner focus lens system, in order from an object side to an image side, comprising a first lens unit, and subsequent lens units, wherein 
     the first lens unit is fixed with respect to an image surface in focusing from an infinity in-focus condition to a close-object in-focus condition, 
     the first lens unit includes: a first positive lens element being located closest to the object side, and having positive optical power; and a second positive lens element having positive optical power, 
     the subsequent lens units include at least a first focusing lens unit located closest to the object side, and a second focusing lens unit, as focusing lens units that move along an optical axis in the focusing, 
     the subsequent lens units include an image blur compensating lens unit that moves in a direction perpendicular to the optical axis to optically compensate image blur, and 
     the following condition (8) is satisfied:
 
 L   A   /f   A &lt;1.2  (8)
 
     where 
     L A  is an overall length of the inner focus lens system (a distance from an object side surface of the first positive lens element to the image surface), and 
     f A  is a focal length of the entire inner focus lens system. 
     The novel concepts disclosed herein were achieved in order to solve the foregoing problems in the related art, and herein is disclosed: 
     a camera system comprising: 
     an interchangeable lens apparatus including an inner focus lens system; and 
     a camera body which is detachably connected to the interchangeable lens apparatus via a camera mount section, and includes an image sensor for receiving an optical image formed by the inner focus lens system and converting the optical image into an electric image signal, wherein 
     the inner focus lens system is an inner focus lens system, in order from an object side to an image side, comprising a first lens unit, and subsequent lens units, wherein 
     the first lens unit is fixed with respect to an image surface in focusing from an infinity in-focus condition to a close-object in-focus condition, 
     the first lens unit includes: a first positive lens element being located closest to the object side, and having positive optical power; and a second positive lens element having positive optical power, 
     the subsequent lens units include at least a first focusing lens unit located closest to the object side, and a second focusing lens unit, as focusing lens units that move along an optical axis in the focusing, 
     the subsequent lens units include an image blur compensating lens unit that moves in a direction perpendicular to the optical axis to optically compensate image blur, and 
     the following condition (8) is satisfied:
 
 L   A   /f   A &lt;1.2  (8)
 
     where 
     L A  is an overall length of the inner focus lens system (a distance from an object side surface of the first positive lens element to the image surface), and 
     f A  is a focal length of the entire inner focus lens system. 
     The inner focus lens system according to the present disclosure is compact, sufficiently suppresses occurrence of various aberrations, and has high resolution and excellent performance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       This and other objects and features of the present disclosure will become clear from the following description, taken in conjunction with the exemplary embodiments with reference to the accompanied drawings in which: 
         FIG. 1  is a lens arrangement diagram showing an infinity in-focus condition and a close-object in-focus condition of an inner focus lens system according to Embodiment 1 (Numerical Example 1); 
         FIG. 2  is a longitudinal aberration diagram of an infinity in-focus condition and a close-object in-focus condition of the inner focus lens system according to Numerical Example 1, 
         FIG. 3  is a lateral aberration diagram of an infinity in-focus condition of the inner focus lens system according to Numerical Example 1, in a basic state where image blur compensation is not performed and in an image blur compensation state; 
         FIG. 4  is a lens arrangement diagram showing an infinity in-focus condition and a close-object in-focus condition of an inner focus lens system according to Embodiment 2 (Numerical Example 2); 
         FIG. 5  is a longitudinal aberration diagram of an infinity in-focus condition and a close-object in-focus condition of the inner focus lens system according to Numerical Example 2; 
         FIG. 6  is a lateral aberration diagram of an infinity in-focus condition of the inner focus lens system according to Numerical Example 2, in a basic state where image blur compensation is not performed and in an image blur compensation state; 
         FIG. 7  is a lens arrangement diagram showing an infinity in-focus condition and a close-object in-focus condition of an inner focus lens system according to Embodiment 3 (Numerical Example 3); 
         FIG. 8  is a longitudinal aberration diagram of an infinity in-focus condition and a close-object in-focus condition of the inner focus lens system according to Numerical Example 3; 
         FIG. 9  is a lateral aberration diagram of an infinity in-focus condition of the inner focus lens system according to Numerical Example 3, in a basic state where image blur compensation is not performed and in an image blur compensation state; 
         FIG. 10  is a lens arrangement diagram showing an infinity in-focus condition and a close-object in-focus condition of an inner focus lens system according to Embodiment 4 (Numerical Example 4); 
         FIG. 11  is a longitudinal aberration diagram of an infinity in-focus condition and a close-object in-focus condition of the inner focus lens system according to Numerical Example 4; 
         FIG. 12  is a lateral aberration diagram of an infinity in-focus condition of the inner focus lens system according to Numerical Example 4, in a basic state where image blur compensation is not performed and in an image blur compensation state; 
         FIG. 13  is a lens arrangement diagram showing an infinity in-focus condition and a close-object in-focus condition of an inner focus lens system according to Embodiment 5 (Numerical Example 5); 
         FIG. 14  is a longitudinal aberration diagram of an infinity in-focus condition and a close-object in-focus condition of the inner focus lens system according to Numerical Example 5; 
         FIG. 15  is a lateral aberration diagram of an infinity in-focus condition of the inner focus lens system according to Numerical Example 5, in a basic state where image blur compensation is not performed and in an image blur compensation state; and 
         FIG. 16  is a schematic construction diagram of an interchangeable-lens type digital camera system according to Embodiment 6. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments will be described with reference to the drawings as appropriate. However, descriptions more detailed than necessary may be omitted. For example, detailed description of already well known matters or description of substantially identical configurations may be omitted. This is intended to avoid redundancy in the description below, and to facilitate understanding of those skilled in the art. 
     It should be noted that the applicants provide the attached drawings and the following description so that those skilled in the art can fully understand this disclosure. Therefore, the drawings and description are not intended to limit the subject defined by the claims. 
     Embodiments 1 to 5 
       FIGS. 1, 4, 7, 10, and 13  are lens arrangement diagrams of inner focus lens systems according to Embodiments 1 to 5, respectively. 
     In each Fig., part (a) shows a lens configuration in an infinity in-focus condition, and part (b) shows a lens configuration in a close-object in-focus condition (object distance: 1 m). In addition, in each Fig., a linear arrow provided between part (a) and part (b) indicates a straight line obtained by connecting the positions of each lens unit in the infinity in-focus condition and the close-object in-focus condition in order from the top. In the part between the infinity in-focus condition and the close-object in-focus condition, the positions are connected simply with a straight line, and therefore, this line does not indicate actual motion of each lens unit. 
     In each Fig., symbol (+) or (−) imparted to the symbol of each lens unit corresponds to the sign of the optical power of the lens unit. In addition, in each Fig., a straight line located on the most right-hand side indicates the position of an image surface S. 
     Embodiment 1 
     As shown in  FIG. 1 , the first lens unit G 1 , in order from the object side to the image side, comprises: a positive meniscus first lens element L 1  with the convex surface facing the object side; a positive meniscus second lens element L 2  with the convex surface facing the object side; a positive meniscus third lens element L 3  with the convex surface facing the object side; 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 object side; and a positive meniscus sixth lens element L 6  with the convex surface facing the object side. Among these, the third lens element L 3  and the fourth lens element L 4  are cemented with each other, and the fifth lens element L 5  and the sixth lens element L 6  are cemented with each other. 
     The second lens unit G 2  comprises solely a negative meniscus seventh lens element L 7  with the convex surface facing the object side. 
     The third lens unit G 3 , in order from the object side to the image side, comprises: a bi-convex eighth lens element L 8 ; a bi-concave ninth lens element L 9 ; a bi-convex tenth lens element L 10 ; a bi-concave eleventh lens element L 11 ; a bi-convex twelfth lens element L 12 ; and a bi-concave thirteenth lens element L 13 . Among these, the eighth lens element L 8  and the ninth lens element L 9  are cemented with each other, and the eleventh lens element L 11 , the twelfth lens element L 12 , and the thirteenth lens element L 13  are cemented with each other. 
     In the third lens unit G 3 , an aperture diaphragm A is provided on the object side relative to the eighth lens element L 8 . 
     The fourth lens unit G 4  comprises solely a positive meniscus fourteenth lens element L 14  with the convex surface facing the image side. 
     The fifth lens unit G 5  comprises solely a positive meniscus fifteenth lens element L 15  with the convex surface facing the image side. 
     In the inner focus lens system according to Embodiment 1, in focusing from an infinity in-focus condition to a close-object in-focus condition, the second lens unit G 2  moves to the image side along the optical axis, and the fourth lens unit G 4  moves to the object side along the optical axis. 
     Further, the tenth lens element L 10  as a part of the third lens unit G 3  corresponds to an image blur compensating lens unit described later. By moving the tenth lens element L 10  in a direction perpendicular to the optical axis, image point movement caused by vibration of the entire system can be compensated. That is, image blur caused by hand blurring, vibration and the like can be compensated optically. 
     Embodiment 2 
     As shown in  FIG. 4 , the first lens unit G 1 , in order from the object side to the image side, comprises: a positive meniscus first lens element L 1  with the convex surface facing the object side; a positive meniscus second lens element L 2  with the convex surface facing the object side; a positive meniscus third lens element L 3  with the convex surface facing the object side; 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 object side; and a positive meniscus sixth lens element L 6  with the convex surface facing the object side. Among these, the third lens element L 3  and the fourth lens element L 4  are cemented with each other, and the fifth lens element L 5  and the sixth lens element L 6  are cemented with each other. 
     The second lens unit G 2  comprises solely a negative meniscus seventh lens element L 7  with the convex surface facing the object side. 
     The third lens unit G 3 , in order from the object side to the image side, comprises: a bi-convex eighth lens element L 8 ; a bi-concave ninth lens element L 9 ; a bi-convex tenth lens element L 10 ; a bi-concave eleventh lens element L 11 ; a bi-convex twelfth lens element L 12 ; and a bi-concave thirteenth lens element L 13 . Among these, the eighth lens element L 8  and the ninth lens element L 9  are cemented with each other, and the eleventh lens element L 11 , the twelfth lens element L 12 , and the thirteenth lens element L 13  are cemented with each other. 
     In the third lens unit G 3 , an aperture diaphragm A is provided on the object side relative to the eighth lens element L 8 . 
     The fourth lens unit G 4  comprises solely a positive meniscus fourteenth lens element L 14  with the convex surface facing the image side. 
     The fifth lens unit G 5  comprises solely a positive meniscus fifteenth lens element L 15  with the convex surface facing the image side. 
     In the inner focus lens system according to Embodiment 2, in focusing from an infinity in-focus condition to a close-object in-focus condition, the second lens unit G 2  moves to the image side along the optical axis, and the fourth lens unit G 4  moves to the object side along the optical axis. 
     Further, the tenth lens element L 10  as a part of the third lens unit G 3  corresponds to an image blur compensating lens unit described later. By moving the tenth lens element L 10  in a direction perpendicular to the optical axis, image point movement caused by vibration of the entire system can be compensated. That is, image blur caused by hand blurring, vibration and the like can be compensated optically. 
     Embodiment 3 
     As shown in  FIG. 7 , the first lens unit G 1 , in order from the object side to the image side, comprises: a positive meniscus first lens element L 1  with the convex surface facing the object side; a positive meniscus second lens element L 2  with the convex surface facing the object side; a bi-convex third lens element L 3 ; a bi-concave fourth lens element L 4 ; a negative meniscus fifth lens element L 5  with the convex surface facing the object side; and a positive meniscus sixth lens element L 6  with the convex surface facing the object side. Among these, the third lens element L 3  and the fourth lens element L 4  are cemented with each other, and the fifth lens element L 5  and the sixth lens element L 6  are cemented with each other. 
     The second lens unit G 2 , in order from the object side to the image side, comprises: a bi-convex seventh lens element L 7 ; and a bi-concave eighth lens element L 8 . The seventh lens element L 7  and the eighth lens element L 8  are cemented with each other. 
     The third lens unit G 3 , in order from the object side to the image side, comprises: 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-concave twelfth lens element L 12 ; a bi-convex thirteenth lens element L 13 ; and a bi-concave fourteenth lens element L 14 . Among these, the ninth lens element L 9  and the tenth lens element L 10  are cemented with each other, and the twelfth lens element L 12 , the thirteenth lens element L 13 , and the fourteenth lens element L 14  are cemented with each other. 
     In the third lens unit G 3 , an aperture diaphragm A is provided on the object side relative to the ninth lens element L 9 . 
     The fourth lens unit G 4 , in order from the object side to the image side, comprises: a positive meniscus fifteenth lens element L 15  with the convex surface facing the image side; and a negative meniscus sixteenth lens element L 16  with the convex surface facing the image side. The fifteenth lens element L 15  and the sixteenth lens element L 16  are cemented with each other. 
     The fifth lens unit G 5  comprises solely a positive meniscus seventeenth lens element L 17  with the convex surface facing the image side. 
     In the inner focus lens system according to Embodiment 3, in focusing from an infinity in-focus condition to a close-object in-focus condition, the second lens unit G 2  moves to the image side along the optical axis, and the fourth lens unit G 4  moves to the object side along the optical axis. 
     Further, the eleventh lens element L 11  as a part of the third lens unit G 3  corresponds to an image blur compensating lens unit described later. By moving the eleventh lens element L 11  in a direction perpendicular to the optical axis, image point movement caused by vibration of the entire system can be compensated. That is, image blur caused by hand blurring, vibration and the like can be compensated optically. 
     Embodiment 4 
     As shown in  FIG. 10 , the first lens unit G 1 , in order from the object side to the image side, comprises: a positive meniscus first lens element L 1  with the convex surface facing the object side; a positive meniscus second lens element L 2  with the convex surface facing the object side; a positive meniscus third lens element L 3  with the convex surface facing the object side; 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 object side; and a positive meniscus sixth lens element L 6  with the convex surface facing the object side. Among these, the third lens element L 3  and the fourth lens element L 4  are cemented with each other, and the fifth lens element L 5  and the sixth lens element L 6  are cemented with each other. 
     The second lens unit G 2  comprises solely a negative meniscus seventh lens element L 7  with the convex surface facing the object side. 
     The third lens unit G 3 , in order from the object side to the image side, comprises: a bi-convex eighth lens element L 8 ; a bi-concave ninth lens element L 9 ; a bi-convex tenth lens element L 10 ; a bi-concave eleventh lens element L 11 ; a bi-convex twelfth lens element L 12 ; and a bi-concave thirteenth lens element L 13 . Among these, the eighth lens element L 8  and the ninth lens element L 9  are cemented with each other, and the eleventh lens element L 11 , the twelfth lens element L 12 , and the thirteenth lens element L 13  are cemented with each other. 
     In the third lens unit G 3 , an aperture diaphragm A is provided on the object side relative to the eighth lens element L 8 . 
     The fourth lens unit G 4 , in order from the object side to the image side, comprises: a bi-convex fourteenth lens element L 14 ; and a negative meniscus fifteenth lens element L 15  with the convex surface facing the image side. The fourteenth lens element L 14  and the fifteenth lens element L 15  are cemented with each other. 
     The fifth lens unit G 5  comprises solely a negative meniscus sixteenth lens element L 16  with the convex surface facing the image side. 
     In the inner focus lens system according to Embodiment 4, in focusing from an infinity in-focus condition to a close-object in-focus condition, the second lens unit G 2  moves to the image side along the optical axis, and the fourth lens unit G 4  moves to the object side along the optical axis. 
     Further, the tenth lens element L 10  as a part of the third lens unit G 3  corresponds to an image blur compensating lens unit described later. By moving the tenth lens element L 10  in a direction perpendicular to the optical axis, image point movement caused by vibration of the entire system can be compensated. That is, image blur caused by hand blurring, vibration and the like can be compensated optically. 
     Embodiment 5 
     As shown in  FIG. 13 , the first lens unit G 1 , in order from the object side to the image side, comprises: a positive meniscus first lens element L 1  with the convex surface facing the object side; a positive meniscus second lens element L 2  with the convex surface facing the object side; a positive meniscus third lens element L 3  with the convex surface facing the object side; a negative meniscus fourth lens element L 4  with the convex surface facing the object side; and a positive meniscus fifth lens element L 5  with the convex surface facing the object side. Among these, the third lens element L 3  and the fourth lens element L 4  are cemented with each other. 
     The second lens unit G 2  comprises solely a negative meniscus sixth lens element L 6  with the convex surface facing the object side. 
     The third lens unit G 3 , in order from the object side to the image side, comprises: a bi-convex seventh lens element L 7 ; a bi-concave 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 ; and a bi-concave twelfth lens element L 12 . Among these, the seventh lens element L 7  and the eighth lens element L 8  are cemented with each other, and the tenth lens element L 10 , the eleventh lens element L 11 , and the twelfth lens element L 12  are cemented with each other. 
     In the third lens unit G 3 , an aperture diaphragm A is provided on the object side relative to the seventh lens element L 7 . 
     The fourth lens unit G 4 , in order from the object side to the image side, comprises: a bi-convex thirteenth lens element L 13 ; and a negative meniscus fourteenth lens element L 14  with the convex surface facing the image side. The thirteenth lens element L 13  and the fourteenth lens element L 14  are cemented with each other. 
     The fifth lens unit G 5  comprises solely a positive meniscus fifteenth lens element L 15  with the convex surface facing the image side. 
     In the inner focus lens system according to Embodiment 5, in focusing from an infinity in-focus condition to a close-object in-focus condition, the second lens unit G 2  moves to the image side along the optical axis, the fourth lens unit G 4  moves to the object side along the optical axis, and the fifth lens unit G 5  moves to the object side along the optical axis. 
     Further, the ninth lens element L 9  as a part of the third lens unit G 3  corresponds to an image blur compensating lens unit described later. By moving the ninth lens element L 9  in a direction perpendicular to the optical axis, image point movement caused by vibration of the entire system can be compensated. That is, image blur caused by hand blurring, vibration and the like can be compensated optically. 
     In the inner focus lens systems according to Embodiments 1 to 5, the first lens unit G 1  is fixed with respect to the image surface in focusing from an infinity in-focus condition to a close-object in-focus condition. Therefore, variation in spherical aberration associated with focusing is small, and thus focusing can be performed with excellent imaging characteristics being maintained. 
     In the inner focus lens systems according to Embodiments 1 to 5, the first lens unit G 1  includes: the first positive lens element being located closest to the object side, and having positive optical power; and the second positive lens element having positive optical power. Therefore, it is possible to provide an inner focus lens system in which axial chromatic aberration is small. 
     In the inner focus lens systems according to Embodiments 1 to 5, the subsequent lens units are provided on the image side relative to the first lens unit G 1 , and the subsequent lens units include the first focusing lens unit located closest to the object side, and the second focusing lens unit, as focusing lens units that move along the optical axis in focusing from an infinity in-focus condition to a close-object in-focus condition. Therefore, variation in spherical aberration associated with focusing is small, and thus focusing can be performed with excellent imaging characteristics being maintained. 
     In the inner focus lens systems according to Embodiments 1 to 5, at least one of the first focusing lens unit and the second focusing lens unit is composed of two or less lens elements. Therefore, high-speed and silent focusing can be performed. 
     In the inner focus lens systems according to Embodiments 1 to 5, the subsequent lens units include an image blur compensating lens unit that moves in a direction perpendicular to the optical axis to optically compensate image blur. Therefore, deterioration in the image due to hand blurring can be reduced. 
     In the disclosure, the image blur compensating lens unit may be one lens unit, or may be any one of a plurality of lens elements or at least two lens elements that are adjacent with each other among the plurality of lens elements when a lens unit is constituted of the plurality of lens elements. 
     As described above, Embodiments 1 to 5 have been described as examples of art disclosed in the present application. However, the art in the present disclosure is not limited to these embodiments. It is understood that various modifications, replacements, additions, omissions, and the like have been performed in these embodiments to give optional embodiments, and the art in the present disclosure can be applied to the optional embodiments. 
     The following description is given for conditions that an inner focus lens system like the inner focus lens systems according to Embodiments 1 to 5 can satisfy. Here, a plurality of conditions are set forth for the inner focus lens system according to each embodiment. A construction that satisfies all the plural conditions is most effective for the inner focus lens system. However, when an individual condition is satisfied, an inner focus lens system having the corresponding effect is obtained. 
     For example, 
     in an inner focus lens system like the inner focus lens systems according to Embodiments 1 to 5, which comprises, in order from an object side to an image side, a first lens unit and subsequent lens units, wherein the first lens unit is fixed with respect to an image surface in focusing from an infinity in-focus condition to a close-object in-focus condition, the first lens unit includes: a first positive lens element being located closest to the object side, and having positive optical power; and a second positive lens element having positive optical power, the subsequent lens units include only a first focusing lens unit located closest to the object side, and a second focusing lens unit, as focusing lens units that move along an optical axis in the focusing, at least one of the first focusing lens unit and the second focusing lens unit is composed of two or less lens elements, and the subsequent lens units include an image blur compensating lens unit that moves in a direction perpendicular to the optical axis to optically compensate image blur (this lens configuration is referred to as a basic configuration I of the embodiment, hereinafter), and in an inner focus lens system like the inner focus lens systems according to Embodiments 1 to 5, which comprises, in order from an object side to an image side, a first lens unit and subsequent lens units, wherein the first lens unit is fixed with respect to an image surface in focusing from an infinity in-focus condition to a close-object in-focus condition, the first lens unit includes: a first positive lens element being located closest to the object side, and having positive optical power; and a second positive lens element having positive optical power, the subsequent lens units include at least a first focusing lens unit located closest to the object side, and a second focusing lens unit, as focusing lens units that move along an optical axis in the focusing, and the subsequent lens units include an image blur compensating lens unit that moves in a direction perpendicular to the optical axis to optically compensate image blur (this lens configuration is referred to as a basic configuration II of the embodiment, hereinafter), it is beneficial that the following condition (1) is satisfied.
 
ν d   L1 &lt;35  (1)
 
     where 
     νd L1  is the Abbe number to the d-line of the first positive lens element. 
     The condition (1) sets forth the Abbe number of the first positive lens element. When the value exceeds the upper limit of the condition (1), chromatic aberration that occurs in the first lens unit becomes excessively large, which makes it difficult to suppress occurrence of axial chromatic aberration. 
     When the following condition (1)′ is satisfied, the above-mentioned effect is achieved more successfully.
 
ν d   L1 &lt;25  (1)′
 
     It is beneficial that an inner focus lens system having the basic configuration I and an inner focus lens system having the basic configuration II, like the inner focus lens systems according to Embodiments 1 to 5, satisfy the following condition (2):
 
 nd   L1 &gt;1.8  (2)
 
     where 
     nd L1  is the refractive index to the d-line of the first positive lens element. 
     The condition (2) sets forth the refractive index of the first positive lens element. When the value goes below the lower limit of the condition (2), it becomes difficult to suppress occurrence of spherical aberration. 
     When the following condition (2)′ is satisfied, the above-mentioned effect is achieved more successfully.
 
 nd   L1 &gt;1.86  (2)′
 
     It is beneficial that an inner focus lens system having the basic configuration I and an inner focus lens system having the basic configuration II, like the inner focus lens systems according to Embodiments 1 to 5, satisfy the following condition (3):
 
1 &lt;|f   F1   /f   F2 |&lt;3  (3)
 
     where 
     f F1  is the focal length of the first focusing lens unit, and 
     f F2  is the focal length of the second focusing lens unit. 
     The condition (3) sets forth the ratio of the focal length of the first focusing lens unit to the focal length of the second focusing lens unit. When the value goes below the lower limit of the condition (3), the optical power of the first focusing lens unit becomes excessively strong, which makes it difficult to suppress variation in astigmatism associated with focusing. When the value exceeds the upper limit of the condition (3), the optical power of the second focusing lens unit becomes excessively strong, which makes it difficult to suppress variation in axial chromatic aberration associated with focusing. 
     When at least one of the following conditions (3)′ and (3)″ is satisfied, the above-mentioned effect is achieved more successfully.
 
1.5 &lt;|f   F1   /f   F2 |  (3)′
 
| f   F1   /f   F2 |&lt;2.2  (3)″
 
     It is beneficial that an inner focus lens system having the basic configuration I and an inner focus lens system having the basic configuration II, like the inner focus lens systems according to Embodiments 1 to 5, satisfy the following condition (4):
 
0.1 &lt;|f   OIS   /f   A |&lt;2 . . .  (4)
 
     where 
     f OIS  is the focal length of the image blur compensating lens unit, and 
     f A  is the focal length of the entire inner focus lens system. 
     The condition (4) sets forth the ratio of the focal length of the image blur compensating lens unit to the focal length of the entire inner focus lens system. When the value goes below the lower limit of the condition (4), the optical power of the image blur compensating lens unit becomes excessively strong, which makes it difficult to suppress occurrence of decentering coma aberration associated with image blur compensation. When the value exceeds the upper limit of the condition (4), the optical power of the image blur compensating lens unit becomes excessively weak, and the amount of movement of the image blur compensating lens unit in the perpendicular direction in image blur compensation is increased, which makes it difficult to achieve size reduction of the inner focus lens system. 
     When at least one of the following conditions (4)′ and (4)″ is satisfied, the above-mentioned effect is achieved more successfully.
 
0.2 &lt;|f   OIS   /f   A |  (4)′
 
| f   OIS   /f   A |&lt;0.4  (4)″
 
     It is beneficial that an inner focus lens system having the basic configuration I and an inner focus lens system having the basic configuration II, like the inner focus lens systems according to Embodiments 1 to 5, satisfy the following condition (5):
 
0.1 &lt;|f   OIS   /f   F1 |&lt;1.2  (5)
 
     where 
     f OIS  is the focal length of the image blur compensating lens unit, and 
     f F1  is the focal length of the first focusing lens unit. 
     The condition (5) sets forth the ratio of the focal length of the image blur compensating lens unit to the focal length of the first focusing lens unit. When the value goes below the lower limit of the condition (5), the optical power of the image blur compensating lens unit becomes excessively strong, which makes it difficult to suppress occurrence of decentering coma aberration associated with image blur compensation. When the value exceeds the upper limit of the condition (5), the optical power of the image blur compensating lens unit becomes excessively weak, and the amount of movement of the image blur compensating lens unit in the perpendicular direction in image blur compensation is increased, which makes it difficult to achieve size reduction of the inner focus lens system. 
     When at least one of the following conditions (5)′ and (5)″ is satisfied, the above-mentioned effect is achieved more successfully.
 
0.3 &lt;|f   OIS   /f   F1 |  (5)′
 
| f   OIS   /f   F1 |&lt;0.5  (5)″
 
     It is beneficial that an inner focus lens system having the basic configuration I and an inner focus lens system having the basic configuration II, like the inner focus lens systems according to Embodiments 1 to 5, satisfy the following condition (6):
 
0.3 &lt;|f   G1   /f   F1 |&lt;1.1  (6)
 
     where 
     f G1  is the focal length of the first lens unit, and 
     f F1  is the focal length of the first focusing lens unit. 
     The condition (6) sets forth the ratio of the focal length of the first lens unit to the focal length of the first focusing lens unit. When the value goes below the lower limit of the condition (6), the optical power of the first lens unit becomes excessively strong, which makes it difficult to suppress occurrences of spherical aberration and axial chromatic aberration. When the value exceeds the upper limit of the condition (6), the optical power of the first focusing lens unit becomes excessively strong, which makes it difficult to suppress variation in astigmatism associated with focusing. 
     When at least one of the following conditions (6)′ and (6)″ is satisfied, the above-mentioned effect is achieved more successfully.
 
0.6 &lt;|f   G1   /f   F1 |  (6)′
 
| f   G1   /f   F1 |&lt;1.0  (6)″
 
     It is beneficial that an inner focus lens system having the basic configuration I and an inner focus lens system having the basic configuration II, like the inner focus lens systems according to Embodiments 1 to 5, satisfy the following condition (7):
 
| TH   F2   /f   A |&lt;0.05  (7)
 
     where 
     TH F2  is the optical axial thickness of the second focusing lens unit, and 
     f A  is the focal length of the entire inner focus lens system. 
     The condition (7) sets forth the ratio of the optical axial thickness of the second focusing lens unit to the focal length of the entire inner focus lens system. When the value exceeds the upper limit of the condition (7), the optical axial thickness of the second focusing lens unit is excessively increased, which makes it difficult to suppress variation in axial chromatic aberration associated with focusing. 
     When the following condition (7)′ is satisfied, the above-mentioned effect is achieved more successfully.
 
| TH   F2   /f   A |&lt;0.04  (7)′
 
     For example, in an inner focus lens system having the basic configuration II like the inner focus lens systems according to Embodiments 1 to 5, the following condition (8) is satisfied:
 
 L   A   /f   A &lt;1.2  (8)
 
     where 
     L A  is the overall length of the inner focus lens system (the distance from an object side surface of the first positive lens element to the image surface), and 
     f A  is the focal length of the entire inner focus lens system. 
     The condition (8) sets forth the ratio of the overall length of the inner focus lens system to the focal length of the entire inner focus lens system. When the value exceeds the upper limit of the condition (8), the focal length of the entire inner focus lens system becomes excessively short, which makes it difficult to suppress astigmatism. 
     When the following condition (8)′ is satisfied, the above-mentioned effect is achieved more successfully.
 
 L   A   /f   A &lt;1.1  (8)′
 
     The individual lens units constituting the inner focus lens systems according to Embodiments 1 to 5 are each 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 having different refractive indices). However, the present disclosure is not limited to this construction. For example, the lens units may employ diffractive type lens elements that deflect incident light by diffraction; refractive-diffractive hybrid type lens elements that deflect incident light by a combination of diffraction and refraction; or gradient index type lens elements that deflect incident light by distribution of refractive index in the medium. In particular, in the refractive-diffractive hybrid type lens element, when a diffraction structure is formed in the interface between media having different refractive indices, wavelength dependence of the diffraction efficiency is improved. 
     The individual lens elements constituting the inner focus lens systems according to Embodiments 1 to 5 may be lens elements each prepared by cementing a transparent resin layer made of ultraviolet-ray curable resin on a surface of a glass lens element. Because the optical power of the transparent resin layer is weak, the glass lens element and the transparent resin layer are totally counted as one lens element. In the same manner, when a lens element that is similar to a plane plate is located, the lens element that is similar to a plane plate is not counted as one lens element because the optical power of the lens element that is similar to a plane plate is weak. 
     Embodiment 6 
       FIG. 16  is a schematic construction diagram of an interchangeable-lens type digital camera system according to Embodiment 6. 
     The interchangeable-lens type digital camera system  100  according to Embodiment 6 includes a camera body  101 , and an interchangeable lens apparatus  201  which is detachably connected to the camera body  101 . 
     The camera body  101  includes: an image sensor  102  which receives an optical image formed by an inner focus lens system  202  of the interchangeable lens apparatus  201 , and converts the optical image into an electric image signal; a liquid crystal monitor  103  which displays the image signal obtained by the image sensor  102 ; and a camera mount section  104 . On the other hand, the interchangeable lens apparatus  201  includes: an inner focus lens system  202  according to any of Embodiments 1 to 5; a lens barrel  203  which holds the inner focus lens system  202 ; and a lens mount section  204  connected to the camera mount section  104  of the camera body  101 . The camera mount section  104  and the lens mount section  204  are physically connected to each other. Moreover, the camera mount section  104  and the lens mount section  204  function as interfaces which allow the camera body  101  and the interchangeable lens apparatus  201  to exchange signals, by electrically connecting a controller (not shown) in the camera body  101  and a controller (not shown) in the interchangeable lens apparatus  201 . In  FIG. 16 , the inner focus lens system according to Embodiment 1 is employed as the inner focus lens system  202 . 
     In Embodiment 6, since the inner focus lens system  202  according to any of Embodiments 1 to 5 is employed, a compact interchangeable lens apparatus having excellent imaging performance can be realized at low cost. Moreover, size reduction and cost reduction of the entire camera system  100  according to Embodiment 6 can be achieved. 
     In the interchangeable-lens type digital camera system according to Embodiment 6, the inner focus lens systems according to Embodiments 1 to 5 are shown as the inner focus lens system  202 , and the entire focusing range need not be used in these inner focus lens systems. That is, in accordance with a desired focusing range, a range where satisfactory optical performance is obtained may exclusively be used. 
     An imaging device comprising each of the inner focus lens systems according to Embodiments 1 to 5, and an image sensor such as a CCD or a CMOS may be applied to a camera for a mobile terminal device such as a smart-phone, a surveillance camera in a surveillance system, a Web camera, a vehicle-mounted camera or the like. 
     As described above, Embodiment 6 has been described as an example of art disclosed in the present application. However, the art in the present disclosure is not limited to this embodiment. It is understood that various modifications, replacements, additions, omissions, and the like have been performed in this embodiment to give optional embodiments, and the art in the present disclosure can be applied to the optional embodiments. 
     Numerical examples are described below in which the inner focus lens systems according to Embodiments 1 to 5 are implemented. Here, in the numerical examples, the units of length are all “mm”, while the units of 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. 
       FIGS. 2, 5, 8, 11, and 14  are longitudinal aberration diagrams of the inner focus lens systems according to Numerical Examples 1 to 5, respectively. 
     In each longitudinal aberration diagram, part (a) shows the aberration in an infinity in-focus condition, and part (b) shows the aberration in a close-object in-focus condition. Each longitudinal aberration diagram, in order from the left-hand side, shows the spherical aberration (SA (mm)), the astigmatism (AST (mm)) and the distortion (DIS (%)). In each spherical aberration diagram, the vertical axis indicates the F-number (in each Fig., indicated as F), and the solid line, the short dash line and the long dash line indicate the characteristics to the d-line, the F-line and the C-line, respectively. In each astigmatism diagram, the vertical axis indicates the image height (in each Fig., indicated as H), and the solid line and the dash line indicate the characteristics to the sagittal plane (in each Fig., indicated as “s”) and the meridional plane (in each Fig., indicated as “m”), respectively. In each distortion diagram, the vertical axis indicates the image height (in each Fig., indicated as H). 
       FIGS. 3, 6, 9, 12, and 15  are lateral aberration diagrams of an infinity in-focus condition of the inner focus lens systems according to Numerical Examples 1 to 5, respectively. 
     In each lateral aberration diagram, the aberration diagrams in the upper three parts correspond to a basic state where image blur compensation is not performed at a telephoto limit, while the aberration diagrams in the lower three parts correspond to an image blur compensation state where the image blur compensating lens unit is moved by a predetermined amount in a direction perpendicular to the optical axis at a telephoto limit. Among the lateral aberration diagrams of a basic state, the upper part shows the lateral aberration at an image point of 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. 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 plane is adopted as the plane containing the optical axis of the first lens unit G 1  and the optical axis of the third lens unit G 3 . 
     In the inner focus lens system according to each of Numerical Examples 1 to 5, the amount of movement of the image blur compensating lens unit in a direction perpendicular to the optical axis in an image blur compensation state in an infinity in-focus condition is 0.65 mm. 
     When the shooting distance is infinity, the amount of image decentering in a case that the inner focus lens system inclines by 0.4° is equal to the amount of image decentering in a case that the image blur compensating lens unit displaces in parallel by the above-mentioned value in a direction perpendicular to the optical axis. 
     As seen from the lateral aberration diagrams, satisfactory symmetry is obtained in the lateral aberration at the axial image point. Further, when the lateral aberration at the +70% image point and the lateral aberration at the −70% image point are compared with each other in the basic state, all have a small degree of curvature and almost the same inclination in the aberration curve. Thus, decentering coma aberration and decentering astigmatism are small. This indicates that sufficient imaging performance is obtained even in the image blur compensation state. Further, when the image blur compensation angle of an inner focus lens system is the same, the amount of parallel translation required for image blur compensation decreases with decreasing focal length of the entire inner focus lens system. Thus, at arbitrary focus positions, sufficient image blur compensation can be performed for image blur compensation angles up to 0.4° without degrading the imaging characteristics. 
     Numerical Example 1 
     The inner focus lens system of Numerical Example 1 corresponds to Embodiment 1 shown in  FIG. 1 . Table 1 shows the surface data of the inner focus lens system of Numerical Example 1. Table 2 shows the various data. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Objet surface 
                 ∞ 
                 Variable 
                   
                   
               
               
                  1 
                 61.56450 
                 4.69240 
                 1.92286 
                 20.9 
               
               
                  2 
                 135.49310 
                 0.20000 
               
               
                  3 
                 62.51620 
                 5.79680 
                 1.43700 
                 95.1 
               
               
                  4 
                 320.40420 
                 0.20000 
               
               
                  5 
                 46.67900 
                 7.04750 
                 1.59349 
                 67.0 
               
               
                  6 
                 3705.03860 
                 1.60000 
                 1.90366 
                 31.3 
               
               
                  7 
                 62.15600 
                 10.12130  
               
               
                  8 
                 37.44560 
                 1.30000 
                 2.00069 
                 25.5 
               
               
                  9 
                 21.72900 
                 6.30300 
                 1.43700 
                 95.1 
               
               
                 10 
                 97.59980 
                 Variable 
               
               
                 11 
                 122.06850 
                 1.05000 
                 1.62041 
                 60.3 
               
               
                 12 
                 38.54290 
                 Variable 
               
               
                 13(Diaphragm) 
                 ∞ 
                 2.00000 
               
               
                 14 
                 60.39180 
                 3.59230 
                 1.77250 
                 49.6 
               
               
                 15 
                 −27.34940 
                 1.00000 
                 1.74077 
                 27.8 
               
               
                 16 
                 20.39520 
                 2.66240 
               
               
                 17 
                 34.47190 
                 2.51550 
                 1.88300 
                 40.8 
               
               
                 18 
                 −132.94540 
                 3.03970 
               
               
                 19 
                 −44.93320 
                 1.20000 
                 1.92286 
                 20.9 
               
               
                 20 
                 12.17350 
                 8.12330 
                 1.84666 
                 23.8 
               
               
                 21 
                 −15.45310 
                 0.80000 
                 1.80420 
                 46.5 
               
               
                 22 
                 46.88660 
                 Variable 
               
               
                 23 
                 −254.96420 
                 2.11870 
                 1.92286 
                 20.9 
               
               
                 24 
                 −35.79630 
                 Variable 
               
               
                 25 
                 −21.07090 
                 1.59920 
                 1.48749 
                 70.4 
               
               
                 26 
                 −17.37880 
                 35.34770  
               
               
                 27 
                 ∞ 
                 (BF) 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 (Various data) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                   
                 Infinity 
                 Close 
               
               
                   
                   
               
               
                   
                 Focal length 
                 146.2142 
                 139.0971 
               
               
                   
                 F-number 
                 2.91065 
                 2.92693 
               
               
                   
                 View angle 
                 4.1995 
                 3.5203 
               
               
                   
                 Image height 
                 10.8150 
                 10.8150 
               
               
                   
                 Overall length of lens system 
                 132.5800 
                 132.5800 
               
               
                   
                 BF 
                 0.00000 
                 0.00000 
               
               
                   
                 d0 
                 ∞ 
                 1000.0000 
               
               
                   
                 d10 
                 2.4270 
                 12.7922 
               
               
                   
                 d12 
                 14.2504 
                 3.8852 
               
               
                   
                 d22 
                 7.9192 
                 7.7636 
               
               
                   
                 d24 
                 5.6736 
                 5.8292 
               
               
                   
                 Entrance pupil position 
                 139.4733 
                 156.0545 
               
               
                   
                 Exit pupil position 
                 −104.8342 
                 −104.0063 
               
               
                   
                 Front principal points position 
                 81.7589 
                 62.3095 
               
               
                   
                 Back principal points position 
                 −13.6347 
                 −27.4285 
               
               
                   
                   
               
            
           
           
               
            
               
                 Zoom lens unit data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Back 
               
               
                   
                 Initial 
                   
                 Overall 
                 principal 
                 principal 
               
               
                 Lens 
                 surface 
                 Focal 
                 length of 
                 points 
                 points 
               
               
                 unit 
                 No. 
                 length 
                 lens unit 
                 position 
                 position 
               
               
                   
               
               
                 1 
                 1 
                 77.46029 
                 37.26100 
                 −15.80039 
                 1.06001 
               
               
                 2 
                 11 
                 −91.23168 
                 1.05000 
                 0.95158 
                 1.35046 
               
               
                 3 
                 13 
                 −33.64340 
                 24.93320 
                 15.30012 
                 23.10908 
               
               
                 4 
                 23 
                 44.91530 
                 2.11870 
                 1.27589 
                 2.29783 
               
               
                 5 
                 25 
                 178.16252 
                 1.59920 
                 5.37292 
                 6.03067 
               
               
                   
               
            
           
         
       
     
     Numerical Example 2 
     The inner focus lens system of Numerical Example 2 corresponds to Embodiment 2 shown in  FIG. 4 . Table 3 shows the surface data of the inner focus lens system of Numerical Example 2. Table 4 shows the various data. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                 Variable 
                   
                   
               
               
                  1 
                 57.12540 
                 5.87100 
                 1.84666 
                 23.8 
               
               
                  2 
                 160.83630 
                 12.90360  
               
               
                  3 
                 56.28260 
                 3.92010 
                 1.49700 
                 81.6 
               
               
                  4 
                 120.12150 
                 0.20000 
               
               
                  5 
                 38.20590 
                 6.79070 
                 1.59349 
                 67.0 
               
               
                  6 
                 763.59730 
                 1.60000 
                 2.00100 
                 29.1 
               
               
                  7 
                 32.83580 
                 5.67120 
               
               
                  8 
                 44.70900 
                 1.30000 
                 1.74950 
                 35.0 
               
               
                  9 
                 27.64100 
                 5.87940 
                 1.49700 
                 81.6 
               
               
                 10 
                 253.45580 
                 Variable 
               
               
                 11 
                 176.05290 
                 1.05000 
                 1.62041 
                 60.3 
               
               
                 12 
                 42.89340 
                 Variable 
               
               
                 13(Diaphragm) 
                 ∞ 
                 2.00000 
               
               
                 14 
                 41.49390 
                 8.54550 
                 1.77250 
                 49.6 
               
               
                 15 
                 −31.11700 
                 1.00000 
                 1.74077 
                 27.8 
               
               
                 16 
                 20.95330 
                 2.93600 
               
               
                 17 
                 39.48730 
                 3.12930 
                 1.88300 
                 40.8 
               
               
                 18 
                 −123.85680 
                 3.42830 
               
               
                 19 
                 −53.33040 
                 1.20000 
                 1.92286 
                 20.9 
               
               
                 20 
                 15.79770 
                 9.51370 
                 1.84666 
                 23.8 
               
               
                 21 
                 −22.77160 
                 0.80000 
                 1.80420 
                 46.5 
               
               
                 22 
                 42.74800 
                 Variable 
               
               
                 23 
                 −159.61710 
                 3.66030 
                 1.92286 
                 20.9 
               
               
                 24 
                 −32.12560 
                 Variable 
               
               
                 25 
                 −23.29870 
                 4.86340 
                 1.59349 
                 67.0 
               
               
                 26 
                 −20.73320 
                 39.41020  
               
               
                 27 
                 ∞ 
                 (BF) 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 4 
               
               
                   
               
               
                 (Various data) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                   
                 Infinity 
                 Close 
               
               
                   
                   
               
               
                   
                 Focal length 
                 146.2049 
                 151.8434 
               
               
                   
                 F-number 
                 2.91046 
                 2.92990 
               
               
                   
                 View angle 
                 4.2181 
                 3.4283 
               
               
                   
                 Image height 
                 10.8150 
                 10.8150 
               
               
                   
                 Overall length of lens system 
                 158.5790 
                 158.5796 
               
               
                   
                 BF 
                 0.00000 
                 0.00000 
               
               
                   
                 d0 
                 ∞ 
                 1000.0000 
               
               
                   
                 d10 
                 2.0000 
                 15.4977 
               
               
                   
                 d12 
                 17.1921 
                 3.6949 
               
               
                   
                 d22 
                 7.2754 
                 7.2164 
               
               
                   
                 d24 
                 6.4388 
                 6.4979 
               
               
                   
                 Entrance pupil position 
                 145.2087 
                 164.4178 
               
               
                   
                 Exit pupil position 
                 −152.4921 
                 −151.8204 
               
               
                   
                 Front principal points position 
                 151.2416 
                 136.7664 
               
               
                   
                 Back principal points position 
                 12.3795 
                 −16.6325 
               
               
                   
                   
               
            
           
           
               
            
               
                 Zoom lens unit data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Back 
               
               
                   
                 Initial 
                   
                 Overall 
                 principal 
                 principal 
               
               
                 Lens 
                 surface 
                 Focal 
                 length of 
                 points 
                 points 
               
               
                 unit 
                 No. 
                 length 
                 lens unit 
                 position 
                 position 
               
               
                   
               
               
                 1 
                 1 
                 97.29559 
                 44.13600 
                 −16.31923 
                 0.60322 
               
               
                 2 
                 11 
                 −91.68463 
                 1.05000 
                 0.85931 
                 1.25936 
               
               
                 3 
                 13 
                 −52.45861 
                 32.55280 
                 32.27842 
                 38.33714 
               
               
                 4 
                 23 
                 42.99028 
                 3.66030 
                 2.35084 
                 4.13345 
               
               
                 5 
                 25 
                 185.95998 
                 4.86340 
                 16.24645 
                 19.32090 
               
               
                   
               
            
           
         
       
     
     Numerical Example 3 
     The inner focus lens system of Numerical Example 3 corresponds to Embodiment 3 shown in  FIG. 7 . Table 5 shows the surface data of the inner focus lens system of Numerical Example 3. Table 6 shows the various data. 
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                 Variable 
                   
                   
               
               
                  1 
                 59.25990 
                 5.36050 
                 1.84666 
                 23.8 
               
               
                  2 
                 155.02690 
                 15.79890  
               
               
                  3 
                 63.53140 
                 4.07930 
                 1.49700 
                 81.6 
               
               
                  4 
                 205.58420 
                 0.20000 
               
               
                  5 
                 39.85700 
                 6.49750 
                 1.59349 
                 67.0 
               
               
                  6 
                 −2319.83600 
                 1.60000 
                 2.00100 
                 29.1 
               
               
                  7 
                 32.38380 
                 6.45730 
               
               
                  8 
                 39.13740 
                 1.30000 
                 1.51742 
                 52.1 
               
               
                  9 
                 25.60680 
                 6.24720 
                 1.49700 
                 81.6 
               
               
                 10 
                 213.23710 
                 Variable 
               
               
                 11 
                 136.08920 
                 1.58280 
                 1.58913 
                 61.3 
               
               
                 12 
                 −1015.75810 
                 1.05000 
                 1.69680 
                 55.5 
               
               
                 13 
                 45.79320 
                 Variable 
               
               
                 14(Diaphragm) 
                 ∞ 
                 2.00000 
               
               
                 15 
                 37.64020 
                 4.25240 
                 1.77250 
                 49.6 
               
               
                 16 
                 −36.06540 
                 1.00000 
                 1.72825 
                 28.3 
               
               
                 17 
                 19.81770 
                 3.04910 
               
               
                 18 
                 37.18010 
                 2.61940 
                 1.88300 
                 40.8 
               
               
                 19 
                 −146.80140 
                 2.18370 
               
               
                 20 
                 −74.83170 
                 1.20000 
                 1.92286 
                 20.9 
               
               
                 21 
                 21.95330 
                 8.33650 
                 1.84666 
                 23.8 
               
               
                 22 
                 −28.87900 
                 0.80000 
                 1.80420 
                 46.5 
               
               
                 23 
                 36.61900 
                 Variable 
               
               
                 24 
                 −210.39000 
                 4.12680 
                 1.84666 
                 23.8 
               
               
                 25 
                 −23.15330 
                 1.00000 
                 1.48749 
                 70.4 
               
               
                 26 
                 −67.67760 
                 Variable 
               
               
                 27 
                 −22.47360 
                 2.87620 
                 1.48749 
                 70.4 
               
               
                 28 
                 −19.39190 
                 32.98870  
               
               
                 29 
                 ∞ 
                 (BF) 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 6 
               
               
                   
               
               
                 (Various data) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                   
                 Infinity 
                 Close 
               
               
                   
                   
               
               
                   
                 Focal length 
                 146.2121 
                 139.7634 
               
               
                   
                 F-number 
                 2.91041 
                 2.93601 
               
               
                   
                 View angle 
                 4.2065 
                 3.4912 
               
               
                   
                 Image height 
                 10.8150 
                 10.8150 
               
               
                   
                 Overall length of lens system 
                 149.5919 
                 149.5919 
               
               
                   
                 BF 
                 0.00000 
                 0.00000 
               
               
                   
                 d0 
                 ∞ 
                 1000.0000 
               
               
                   
                 d10 
                 2.0000 
                 13.8501 
               
               
                   
                 d13 
                 15.4075 
                 3.5574 
               
               
                   
                 d23 
                 7.7199 
                 7.3199 
               
               
                   
                 d26 
                 7.8582 
                 8.2582 
               
               
                   
                 Entrance pupil position 
                 153.1459 
                 168.9972 
               
               
                   
                 Exit pupil position 
                 −103.9533 
                 −102.4342 
               
               
                   
                 Front principal points position 
                 93.7195 
                 68.9810 
               
               
                   
                 Back principal points position 
                 3.3856 
                 −11.1400 
               
               
                   
                   
               
            
           
           
               
            
               
                 Zoom lens unit data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Back 
               
               
                   
                 Initial 
                   
                 Overall 
                 principal 
                 principal 
               
               
                 Lens 
                 surface 
                 Focal 
                 length of 
                 points 
                 points 
               
               
                 unit 
                 No. 
                 length 
                 lens unit 
                 position 
                 position 
               
               
                   
               
               
                 1 
                 1 
                 88.84200 
                 47.54070 
                 −3.09370 
                 7.89552 
               
               
                 2 
                 11 
                 −91.84874 
                 2.63280 
                 2.26667 
                 3.26888 
               
               
                 3 
                 14 
                 −58.14058 
                 25.44110 
                 24.33757 
                 30.32740 
               
               
                 4 
                 24 
                 53.07940 
                 5.12680 
                 2.94265 
                 5.18921 
               
               
                 5 
                 27 
                 222.14505 
                 2.87620 
                 10.79809 
                 12.19359 
               
               
                   
               
            
           
         
       
     
     Numerical Example 4 
     The inner focus lens system of Numerical Example 4 corresponds to Embodiment 4 shown in  FIG. 10 . Table 7 shows the surface data of the inner focus lens system of Numerical Example 4. Table 8 shows the various data. 
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                 Variable 
                   
                   
               
               
                  1 
                 57.30010 
                 5.66200 
                 1.84666 
                 23.8 
               
               
                  2 
                 164.89120 
                 2.50290 
               
               
                  3 
                 52.36090 
                 4.67070 
                 1.49700 
                 81.6 
               
               
                  4 
                 111.10980 
                 0.20000 
               
               
                  5 
                 36.03920 
                 7.93970 
                 1.59282 
                 68.6 
               
               
                  6 
                 401.76890 
                 1.60000 
                 1.80610 
                 33.3 
               
               
                  7 
                 28.73000 
                 7.03090 
               
               
                  8 
                 32.91070 
                 1.30000 
                 1.84666 
                 23.8 
               
               
                  9 
                 21.50030 
                 6.51900 
                 1.49700 
                 81.6 
               
               
                 10 
                 93.72630 
                 Variable 
               
               
                 11 
                 143.16010 
                 1.05000 
                 1.60311 
                 60.7 
               
               
                 12 
                 35.59520 
                 Variable 
               
               
                 13(Diaphragm) 
                 ∞ 
                 2.00000 
               
               
                 14 
                 53.64380 
                 3.74480 
                 1.77250 
                 49.6 
               
               
                 15 
                 −31.41830 
                 1.00000 
                 1.68893 
                 31.2 
               
               
                 16 
                 21.63850 
                 2.52430 
               
               
                 17 
                 31.47310 
                 2.58880 
                 1.88300 
                 40.8 
               
               
                 18 
                 −325.84920 
                 2.42530 
               
               
                 19 
                 −60.81460 
                 1.20000 
                 1.92286 
                 20.9 
               
               
                 20 
                 14.13680 
                 8.27140 
                 1.84666 
                 23.8 
               
               
                 21 
                 −50.90930 
                 0.80000 
                 1.80420 
                 46.5 
               
               
                 22 
                 55.71660 
                 Variable 
               
               
                 23 
                 134.00100 
                 3.87560 
                 1.84666 
                 23.8 
               
               
                 24 
                 −21.58420 
                 1.00000 
                 1.48749 
                 70.4 
               
               
                 25 
                 −111.32940 
                 Variable 
               
               
                 26 
                 −16.00760 
                 1.84390 
                 1.80420 
                 46.5 
               
               
                 27 
                 −16.38590 
                 18.77010  
               
               
                 28 
                 ∞ 
                 (BF) 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 8 
               
               
                   
               
               
                 (Various data) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                   
                 Infinity 
                 Close 
               
               
                   
                   
               
               
                   
                 Focal length 
                 104.4078 
                 103.3694 
               
               
                   
                 F-number 
                 2.08038 
                 2.09468 
               
               
                   
                 View angle 
                 5.8884 
                 5.0027 
               
               
                   
                 Image height 
                 10.8150 
                 10.8150 
               
               
                   
                 Overall length of lens system 
                 113.5699 
                 113.5701 
               
               
                   
                 BF 
                 0.00000 
                 0.00000 
               
               
                   
                 d0 
                 ∞ 
                 1000.0000 
               
               
                   
                 d10 
                 2.6009 
                 11.0803 
               
               
                   
                 d12 
                 12.7298 
                 4.2504 
               
               
                   
                 d22 
                 4.4078 
                 4.0078 
               
               
                   
                 d25 
                 5.3120 
                 5.7122 
               
               
                   
                 Entrance pupil position 
                 126.6710 
                 139.8437 
               
               
                   
                 Exit pupil position 
                 −72.5960 
                 −71.0638 
               
               
                   
                 Front principal points position 
                 80.9209 
                 65.1679 
               
               
                   
                 Back principal points position 
                 9.1629 
                 −0.8489 
               
               
                   
                   
               
            
           
           
               
            
               
                 Zoom lens unit data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Back 
               
               
                   
                 Initial 
                   
                 Overall 
                 principal 
                 principal 
               
               
                 Lens 
                 surface 
                 Focal 
                 length of 
                 points 
                 points 
               
               
                 unit 
                 No. 
                 length 
                 lens unit 
                 position 
                 position 
               
               
                   
               
               
                 1 
                 1 
                 75.27599 
                 37.42520 
                 −13.34556 
                 2.74340 
               
               
                 2 
                 11 
                 −78.83944 
                 1.05000 
                 0.87493 
                 1.26754 
               
               
                 3 
                 13 
                 −66.50676 
                 24.55460 
                 21.98558 
                 28.42133 
               
               
                 4 
                 23 
                 37.04790 
                 4.87560 
                 1.73956 
                 3.81801 
               
               
                 5 
                 26 
                 735.26748 
                 1.84390 
                 36.88007 
                 39.59554 
               
               
                   
               
            
           
         
       
     
     Numerical Example 5 
     The inner focus lens system of Numerical Example 5 corresponds to Embodiment 5 shown in  FIG. 13 . Table 9 shows the surface data of the inner focus lens system of Numerical Example 5. Table 10 shows the various data. 
     
       
         
           
               
             
               
                 TABLE 9 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                 Variable 
                   
                   
               
               
                  1 
                 50.97710 
                 6.29410 
                 1.84666 
                 23.8 
               
               
                  2 
                 141.55960 
                 12.79400  
               
               
                  3 
                 51.53990 
                 4.26990 
                 1.49700 
                 81.6 
               
               
                  4 
                 131.37540 
                 0.20000 
               
               
                  5 
                 33.06630 
                 7.08600 
                 1.49700 
                 81.6 
               
               
                  6 
                 14424.79050 
                 1.60000 
                 2.00069 
                 25.5 
               
               
                  7 
                 27.84500 
                 5.82710 
               
               
                  8 
                 41.88650 
                 3.28650 
                 1.59349 
                 67.0 
               
               
                  9 
                 212.41860 
                 Variable 
               
               
                 10 
                 120.59720 
                 1.05000 
                 1.77250 
                 49.6 
               
               
                 11 
                 43.16490 
                 Variable 
               
               
                 12(Diaphragm) 
                 ∞ 
                 2.00000 
               
               
                 13 
                 40.69110 
                 4.42950 
                 1.80420 
                 46.5 
               
               
                 14 
                 −26.19720 
                 1.00000 
                 1.78472 
                 25.7 
               
               
                 15 
                 20.14660 
                 2.81350 
               
               
                 16 
                 35.07530 
                 2.75520 
                 1.88300 
                 40.8 
               
               
                 17 
                 −159.39370 
                 2.26040 
               
               
                 18 
                 −64.84320 
                 1.20000 
                 1.92286 
                 20.9 
               
               
                 19 
                 15.96920 
                 10.02450  
                 1.84666 
                 23.8 
               
               
                 20 
                 −16.17400 
                 0.80000 
                 1.80420 
                 46.5 
               
               
                 21 
                 34.36220 
                 Variable 
               
               
                 22 
                 2369.59610 
                 2.84680 
                 1.84666 
                 23.8 
               
               
                 23 
                 −23.37970 
                 1.00000 
                 1.48749 
                 70.4 
               
               
                 24 
                 −104.02680 
                 Variable 
               
               
                 25 
                 −24.71940 
                 1.83690 
                 1.48749 
                 70.4 
               
               
                 26 
                 −18.46640 
                 Variable 
               
               
                 27 
                 ∞ 
                 (BF) 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 10 
               
               
                   
               
               
                 (Various data) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                   
                 Infinity 
                 Close 
               
               
                   
                   
               
               
                   
                 Focal length 
                 146.2137 
                 138.0775 
               
               
                   
                 F-number 
                 2.91029 
                 2.93167 
               
               
                   
                 View angle 
                 4.2187 
                 3.5357 
               
               
                   
                 Image height 
                 10.8150 
                 10.8150 
               
               
                   
                 Overall length of lens system 
                 138.5579 
                 138.5583 
               
               
                   
                 BF 
                 0.00000 
                 0.00000 
               
               
                   
                 d0 
                 ∞ 
                 1000.0000 
               
               
                   
                 d9 
                 2.0000 
                 12.4283 
               
               
                   
                 d11 
                 14.1607 
                 3.7327 
               
               
                   
                 d21 
                 5.2604 
                 4.9735 
               
               
                   
                 d24 
                 11.9632 
                 11.7245 
               
               
                   
                 d26 
                 29.7992 
                 30.3249 
               
               
                   
                 Entrance pupil position 
                 140.5462 
                 155.4503 
               
               
                   
                 Exit pupil position 
                 −102.7191 
                 −100.8140 
               
               
                   
                 Front principal points position 
                 78.6728 
                 55.4456 
               
               
                   
                 Back principal points position 
                 −7.6370 
                 −20.2541 
               
               
                   
                   
               
            
           
           
               
            
               
                 Zoom lens unit data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Back 
               
               
                   
                 Initial 
                   
                 Overall 
                 principal 
                 principal 
               
               
                 Lens 
                 surface 
                 Focal 
                 length of 
                 points 
                 points 
               
               
                 unit 
                 No. 
                 length 
                 lens unit 
                 position 
                 position 
               
               
                   
               
               
                 1 
                 1 
                 82.20456 
                 41.35760 
                 −9.16048 
                 3.16193 
               
               
                 2 
                 10 
                 −87.54301 
                 1.05000 
                 0.92809 
                 1.38219 
               
               
                 3 
                 12 
                 −41.99048 
                 27.28310 
                 21.09058 
                 28.88220 
               
               
                 4 
                 22 
                 49.15068 
                 3.84680 
                 1.67028 
                 3.30058 
               
               
                 5 
                 25 
                 136.59895 
                 1.83690 
                 4.45310 
                 5.16354 
               
               
                   
               
            
           
         
       
     
     The following Table 11 shows the corresponding values to the individual conditions in the inner focus lens systems of each of Numerical Examples. 
     
       
         
           
               
             
               
                 TABLE 11 
               
             
            
               
                   
               
               
                 (Values corresponding to conditions) 
               
            
           
           
               
               
            
               
                   
                 Numerical Example 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Condition 
                 1 
                 2 
                 3 
                 4 
                 5 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 (1) 
                 vd L1   
                 20.880 
                 23.780 
                 23.780 
                 23.780 
                 23.780 
               
               
                 (2) 
                 nd L1   
                 1.923 
                 1.847 
                 1.847 
                 1.847 
                 1.847 
               
               
                 (3) 
                 |f F1 /f F2 | 
                 2.031 
                 2.133 
                 1.730 
                 2.128 
                 1.781 
               
               
                 (4) 
                 |f OIS /f A | 
                 0.214 
                 0.234 
                 0.231 
                 0.312 
                 0.224 
               
               
                 (5) 
                 |f OIS /f F1 | 
                 0.342 
                 0.373 
                 0.368 
                 0.414 
                 0.374 
               
               
                 (6) 
                 |f G1 /f F1 | 
                 0.849 
                 1.061 
                 0.967 
                 0.955 
                 0.939 
               
               
                 (7) 
                 |TH F2 /f A | 
                 0.016 
                 0.023 
                 0.034 
                 0.043 
                 0.013 
               
               
                 (8) 
                 L A /f A   
                 0.907 
                 1.085 
                 1.023 
                 1.088 
                 0.948 
               
               
                   
               
            
           
         
       
     
     The present disclosure is applicable to a digital still camera, a digital video camera, a camera for a mobile terminal device such as a smart-phone, a surveillance camera in a surveillance system, a Web camera, a vehicle-mounted camera or the like. In particular, the present disclosure is applicable to a photographing optical system where high image quality is required like in a digital still camera system or a digital video camera system. 
     As described above, embodiments have been described as examples of art in the present disclosure. Thus, the attached drawings and detailed description have been provided. 
     Therefore, in order to illustrate the art, not only essential elements for solving the problems but also elements that are not necessary for solving the problems may be included in elements appearing in the attached drawings or in the detailed description. Therefore, such unnecessary elements should not be immediately determined as necessary elements because of their presence in the attached drawings or in the detailed description. 
     Further, since the embodiments described above are merely examples of the art in the present disclosure, it is understood that various modifications, replacements, additions, omissions, and the like can be performed in the scope of the claims or in an equivalent scope thereof.