JP2015212724A - Zoom lens and imaging apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a zoom lens that is telephoto, compact, and lightweight and has small aberration fluctuation due to focus adjustment.SOLUTION: A zoom lens comprises, in order form an object side to an image side: a first lens group having positive refractive power that does not move for zooming; a second lens group having negative refractive power that moves when zooming; one or more lens groups that move when zooming; an aperture diaphragm; and an image forming lens group. The first lens group is composed of three or more sub lens groups including an eleventh lens group having positive refractive power arranged closest to the object side and a first k lens group having negative refractive power arranged closest to the image side. At least two sub lens groups of the three or more sub lens groups move during focus adjustment.

Description

  The present invention relates to a zoom lens suitable for a television camera, a video camera, a surveillance camera, a digital still camera, a silver halide photography camera, and the like, and a zoom lens that is telephoto, small, light, and has little aberration fluctuation due to focus adjustment, and The present invention relates to an image pickup apparatus.

  Conventionally, in a zoom lens that performs focus adjustment by a lens group that is located on the object side of the zoom lens group, as a configuration that is particularly suitable for focus adjustment of a telephoto zoom lens, a lens group having a positive refractive power on the object side, Various so-called telephoto type first group configurations in which a lens group having a negative refractive power is arranged on the image side have been proposed.

  For example, in Patent Document 1, the first lens group includes an eleventh lens group having a positive refractive power, a twelfth lens group having a positive refractive power, and a thirteenth lens group having a negative refractive power. A zoom lens in which the lens group moves is disclosed.

  In addition, various so-called floating focus methods in which a plurality of lens groups move with focusing in a zoom lens that performs focus adjustment by a lens group located on the object side of the variable power lens group have been proposed.

  For example, in Patent Document 2, the first lens group includes an eleventh lens group having a positive refractive power, a twelfth lens group having a negative refractive power, and a thirteenth lens group having a positive refractive power. A zoom lens is disclosed that includes a movable 13th lens unit with positive refractive power, and both the 12th lens unit and the 13th lens unit move toward the object side during focus adjustment from an object at infinity to a near object.

  Further, in Patent Document 3, the first lens group includes an eleventh lens group having a negative refractive power, a twelfth lens group having a positive refractive power, and a thirteenth lens group having a positive refractive power, and is close to an object at infinity. A zoom lens is disclosed in which the twelfth lens group moves to the image side and the thirteenth lens group moves to the object side during focus adjustment to a distance object.

JP 2007-139858 A JP 2012-203297 A JP 2012-242766 A

  In telephoto zoom lenses used in recent television cameras, video cameras, surveillance cameras, and the like, there is a demand for high-performance zoom lenses with less aberration fluctuations due to focus adjustment. In addition, with the widespread use of large-format image sensors having high sensitivity and high resolution, there is an increasing demand for zoom lenses having high performance up to the periphery of the screen.

  In the focus adjustment method of Patent Document 1, aberration fluctuations accompanying the focus adjustment of the telephoto zoom lens remain, and in particular, an imaging system that employs a large format image sensor is reduced in size and weight, and good and uniform optical performance is obtained up to the periphery of the screen. It is difficult to achieve both.

  In the focus adjustment methods of Patent Documents 2 and 3, aberration fluctuations associated with focus adjustment can be corrected satisfactorily, but the telephoto zoom lens is small and light because it does not have a lens configuration that pushes the principal point of the first lens group to the object side. Is difficult to achieve.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom lens and an image pickup apparatus having the same, which have a small aberration variation due to focus adjustment while achieving both super telephoto and small size and light weight.

  The zoom lens according to the present invention includes, in order from the object side to the image side, a first lens unit having a positive refractive power that does not move for zooming, a second lens unit having a negative refractive power that moves during zooming, and a lens unit that moves during zooming. The first lens group includes an eleventh lens group having a positive refractive power closest to the object side and a negative refractive power closest to the image side. It is composed of three or more sub lens groups including the first k lens group, and at least two of the three or more sub lens groups move during the focus adjustment.

  According to the present invention, it is possible to obtain a zoom lens in which the variation in aberration due to focus adjustment is small while achieving both telephotoness and reduction in size and weight.

It is a figure which shows the principle of this invention. FIG. 3 is a lens cross-sectional view when focusing on (A) infinity and (B) close to (3.0 m) at the wide angle end of the zoom lens of Example 1; FIG. 6 is an aberration diagram for focusing on (A) infinity, (B) 10.0 m, and (C) close to (3.0 m) at the wide angle end of the zoom lens according to the first exemplary embodiment. FIG. 6 is an aberration diagram when focusing on (A) infinity, (B) 10.0 m, and (C) close to (3.0 m) at the telephoto end of the zoom lens of Example 1; FIG. 6 is a lens cross-sectional view when focusing on (A) infinity and (B) close to (4.0 m) at the wide angle end of the zoom lens of Example 2; FIG. 6 is an aberration diagram when focusing on (A) infinity, (B) 40.0 m, and (C) close to (4.0 m) at the wide-angle end of the zoom lens of Example 2. FIG. 6 is an aberration diagram when focusing on (A) infinity, (B) 40.0 m, and (C) close to (4.0 m) at the telephoto end of the zoom lens of Example 2; FIG. 6 is a lens cross-sectional view when focusing on (A) infinity (B) close to (4.0 m) at the wide angle end of the zoom lens of Example 3; FIG. 6 is aberration diagrams when focusing on (A) infinity, (B) 10.0 m, and (C) close to (4.0 m) at the wide angle end of the zoom lens according to Example 3; FIG. 12 is aberration diagrams when focusing on (A) infinity, (B) 10.0 m, and (C) close to (4.0 m) at the telephoto end of the zoom lens of Example 3; FIG. 6 is a lens cross-sectional view when focusing on (A) infinity (B) and close to (3.5 m) at the wide-angle end of the zoom lens of Example 4; FIG. 10 is aberration diagrams when focusing on (A) infinity, (B) 40.0 m, and (C) close to (3.5 m) at the wide-angle end of the zoom lens of Example 4. FIG. 10 is aberration diagrams when focusing on (A) infinity, (B) 40.0 m, and (C) close to (3.5 m) at the telephoto end of the zoom lens of Example 4; FIG. 10 is a lens cross-sectional view when focusing on (A) infinity (B) close to (3.5 m) at the wide angle end of the zoom lens of Example 5; FIG. 10 is aberration diagrams when focusing on (A) infinity, (B) 20.0 m, and (C) close to (3.5 m) at the wide angle end of the zoom lens of Example 5. FIG. 6A is an aberration diagram when the zoom lens of Example 5 is in focus at (A) infinity, (B) 20.0 m, and (C) close to (3.5 m) at the telephoto end. 10 is a lens cross-sectional view when focusing on (A) infinity (B) close to (4.0 m) at the wide-angle end of a zoom lens of Example 6. FIG. FIG. 10A is an aberration diagram during focusing on (A) infinity, (B) 20.0 m, and (C) close to (4.0 m) at the wide angle end of the zoom lens according to Example 6; FIG. 10A is an aberration diagram during focusing on (A) infinity, (B) 20.0 m, and (C) close to (4.0 m) at the telephoto end of the zoom lens according to Example 6; It is a conceptual diagram of primary chromatic aberration correction. It is a principal part schematic of the imaging device of this invention.

  Hereinafter, preferred embodiments of a zoom lens according to the present invention will be described in detail with reference to the accompanying drawings.

  The zoom lens according to the present invention includes, in order from the object side to the image side, a first lens unit having a positive refractive power including a focusing lens unit that does not move for zooming, and a negative refraction that moves on the optical axis during zooming. A second lens group of force, one or more lens groups that move during zooming, an aperture stop, and an imaging lens group. The first lens group is composed of three or more sub lens groups as a whole. The three or more sub lens groups include an eleventh lens group having a positive refractive power disposed closest to the object side and a first k lens group having a negative refractive power disposed closest to the image side. Of these sub lens groups, at least two sub lens groups simultaneously move on the optical axis during focus adjustment.

  Here, the optical action when the focus method (so-called floating focus) in which the two lens groups in the present invention are simultaneously moved during the focus adjustment will be described.

  FIG. 1 is an example of an off-axis optical path conceptual diagram of the first lens group at an object distance infinity (A) and a closest object distance (B) at an arbitrary zoom position. In FIG. 1, the left side is the object side, the right side is the image plane side, and in order from the object side to the image side, an eleventh lens unit U11 having a positive refractive power, a twelfth lens unit U12 having a positive refractive power, and a negative refraction. The example of the 1st lens group U1 comprised by the 13th lens group U13 of force is shown.

A general telephoto zoom lens is designed with a balance of aberration correction, lens shape, etc., focusing on an object distance from long distance to infinity. Here, the telephoto lens assumed in the present invention is a lens having the characteristics expressed by the following expression when the lens is attached to the camera and the shooting half angle of view of the effective screen diagonal at the telephoto end is ωt. It is.
0.4 <ωt <3.0 (a)

For example, when only the twelfth lens unit U12 having a positive refractive power is extended from the image side to the object side in order to adjust the focus, the axis at the time of focusing at infinity is the object distance variation from infinity to the close. When the height of the external incident light beam is H11inf and the height of the off-axis incident light beam at the closest focus is H11 mod, the following equation is established.
H11mod <H11inf (b)

  That is, the height of the off-axis incident light beam passing through the eleventh lens unit U11 is lower when the object distance is close than when the object distance is infinity. Due to this effect, when the object distance changes from infinity to close, the magnification of the eleventh lens unit U11 decreases, and the field curvature changes to the over side. Since the eleventh lens unit U11 has a higher off-axis ray height than the other lens units, the eleventh lens unit U11 has a great influence on the curvature of field that increases in proportion to the square of the off-axis ray height. Similarly, in the twelfth lens unit U12 and the thirteenth lens unit U13, the height of the passing light changes in accordance with the focus adjustment from infinity to the closeness. However, when the thirteenth lens unit U13 does not move during the focus adjustment, basically However, the aberration sharing value of the thirteenth lens unit U13 does not change. As a result, as the focus is adjusted from infinity to close, the spherical aberration changes to the under side and the field curvature changes to the over side as an influence of the entire first lens unit U1. Due to this effect, the degree of coincidence between the spherical aberration and the field curvature is poor at short distances, which is a major cause of performance degradation.

  Therefore, the zoom lens according to the present invention is characterized in that the change in the off-axis ray height that occurs during the focus adjustment is corrected by moving the two sub-lens groups as shown in FIG. FIG. 1B is similar to the configuration of the first exemplary embodiment of the zoom lens according to the present invention. As the twelfth lens unit U12 extends from the image side to the object side as the first focus unit, the thirteenth lens unit. U13 is configured to move from the image side to the object side as a floating group. The 13th lens unit U13 generates an under component of the field curvature so as to cancel the over-curvature over-component that increases in the eleventh lens unit U11 and the twelfth lens unit U12 in accordance with the focus adjustment. Corrects fluctuations in the curvature.

  The configuration of these focus adjustment groups is not limited to that of the first embodiment, but can be arbitrarily given by design depending on the power arrangement of the sub lens groups, the way in which the lens intervals are provided, the way off-axis rays, and the like. In general, use of a lens group having a high off-axis light beam is more sensitive to off-axis aberrations, and correction is more efficient. Considering these merits and demerits comprehensively, it is better to optimally configure the floating focus according to the purpose.

  Next, features of the zoom lens of the present invention will be described.

  The zoom lens of the present invention includes, in order from the object side to the image side, a first lens group having a fixed positive refractive power during zooming and a second lens group having a negative refractive power moving on the optical axis during zooming. The first lens group includes three or more sub lens groups, and has an eleventh lens group having a positive refractive power closest to the object side and a first k lens group having a negative refractive power closest to the image side. In this case, at least two lens groups of the sub lens group are configured to move on the optical axis simultaneously.

Furthermore, the zoom lens of the present invention is a sub lens group constituting the first lens group, and the sub lens group moving on the optical axis during focus adjustment is based on the position at the time of focusing on infinity. When the focal length of the lens group having the largest driving amount in focus adjustment is f1P, the maximum movement amount is δ1P, the focal length of the lens group having the second largest driving amount in focus adjustment is f1S, and the maximum movement amount is δ1S. ,
0.03 <| δ1S / δ1P | <1.00 (1)
0.15 <| f1S / f1P | <5.50 (2)
The following conditional expression is satisfied.

  Here, the maximum value of the amount moved with reference to the position at the time of focusing on infinity is defined as follows. For example, when the thirteenth lens unit moves only in one direction along with focus adjustment from the time of focusing on infinity to the closest focusing state, the driving amount from infinity to the closest end becomes the maximum moving amount. However, if the movement direction of the thirteenth lens unit reverses in the middle of the locus from infinity to the in-focus state, the distance from the infinite focus to the farthest position in the locus is the maximum amount of movement. It is defined as As described above, the conditional expression (1) assumes a case where it is desired to intensively correct the optical performance at a desired object distance and a case where it is desired to highly control the locus of focus adjustment.

  Conditional expressions (1) and (2) indicate the amount of movement and the appropriate power arrangement during focus adjustment when a plurality of sub lens groups in the first lens group are selected as the focus adjustment lens group of the zoom lens. It prescribes.

  Conditional expression (1) indicates the ratio of the movement amounts of the first and second sub-lens groups having the longest movement amount from the infinite focus of the plurality of sub-lens groups moving during the focus adjustment in the first lens group. It prescribes. Exceeding the upper limit of conditional expression (1) is not preferable because the movement amount of the sub lens group showing the maximum movement amount becomes excessively large, and it is difficult to reduce the size and weight of the first lens group. Exceeding the lower limit of conditional expression (1) is not preferable because it is difficult to satisfactorily correct aberration fluctuations associated with focus adjustment.

More preferably, conditional expression (1) should be set as follows.
0.05 <| δ1S / δ1P | <0.90 (1a)
More preferably,
0.20 <| δ1S / δ1P | <0.65 (1aa)
Is preferably set.

  Conditional expression (2) defines the ratio of the focal lengths of the first and second longest sub-lens groups among the plurality of sub-lens groups that move during focus adjustment in the first lens group. . When the upper limit of conditional expression (2) is exceeded, the amount of extension of the twelfth lens unit U12 during focus adjustment increases, making it difficult to reduce the size and weight of the first lens unit. When the lower limit of conditional expression (2) is exceeded, the refractive power of the thirteenth lens unit U13 with respect to the twelfth lens unit U12 becomes too weak, and it becomes difficult to satisfactorily correct aberration fluctuations associated with focus adjustment.

More preferably, conditional expression (2) should be set as follows.
0.25 <| f1S / f1P | <4.40 (2a)
More preferably, the conditional expression (2) is 0.35 <| f1S / f1P | <2.00 (2aa)
Is preferably set.

Furthermore, it is more preferable that the zoom lens of the present invention satisfies the following conditions.
When the focal length of the first lens unit U1 at the time of focusing on infinity is f1,
0.5 <f11 / f1 <5.0 (3)
It is more preferable to satisfy the following conditional expression. Conditional expression (3) defines the ratio of the focal length of the eleventh lens group to the first lens group. If the upper limit of conditional expression (3) is exceeded, the focal length of the eleventh lens group becomes relatively long and the amount of movement of the focus adjustment group increases, or the principal point of the first lens group is pushed toward the object side. Since the effect cannot be sufficiently obtained, the lens becomes undesirably large. If the lower limit of conditional expression (3) is exceeded, the refractive power of the eleventh lens group becomes relatively strong (because the radius of curvature of each lens becomes small), and therefore higher-order aberrations and the like particularly increase in the telephoto aberration. Therefore, it is not preferable.

More preferably, conditional expression (3) is more preferably set as follows.
0.6 <f11 / f1 <4.0 (3a)
More preferably, conditional expression (3) is 0.7 <f11 / f1 <3.5 (3aa)
Is preferably set.

In the zoom lens of the present invention, when the focal length in the telephoto end state of the entire lens system is ft,
1.8 <ft / f1 <5.5 (4)
It is more preferable to satisfy. Conditional expression (4) defines the ratio between the focal length ft at the telephoto end of the zoom lens and the focal length f1 of the first lens group. If the upper limit of conditional expression (4) is exceeded, the enlargement magnification for zooming is set to be large with respect to the focal length of the first lens group, and aberration zoom variation, focus movement, and the like increase excessively, which is not preferable. . Exceeding the lower limit of conditional expression (4) is not preferable because the focal length of the first lens group is set excessively long and it is difficult to reduce the size and weight of the first lens group and the subsequent zooming unit.

More preferably, conditional expression (4) is more preferably set as follows.
2.0 <ft / f1 <5.0 (4a)
More preferably, conditional expression (4) is
2.2 <ft / f1 <4.8 (4aa)
Is more preferable.

In the zoom lens of the present invention, when the distance from the center of the most image side lens surface of the first lens group to the image side principal point position is Ok, and the thickness on the optical axis of the first lens group is D1,
0.3 <| Ok / D1 | <1.5 (5)
It is more preferable to satisfy the following conditional expression. Conditional expression (5) is expressed by the distance Ok from the center of the lens surface arranged closest to the image side of the first lens group to the image side principal point position and the thickness D1 of the lens group on the optical axis of the first lens group. Specifies the absolute value of the ratio. The center of the lens surface here refers to a point where the most image side lens surface and an optical axis passing through the center of the lens intersect.

  The first lens group of the present invention forms a so-called telephoto type configuration in which a lens group having a positive refractive power is disposed on the object side and a lens group having a negative refractive power is disposed on the image side. With this configuration, an appropriate focal length is obtained as the first lens group of the telephoto zoom lens, and at the same time, the principal point of the lens is pushed out to the object side to reduce the size and weight. If the upper limit of conditional expression (5) is exceeded, the refractive power of each lens will excessively increase in order to push the image side principal point to the object side, leading to an increase in the generation of higher-order aberrations by each lens having a small curvature radius. It is not preferable. If the lower limit of conditional expression (5) is exceeded, the image-side principal point cannot be sufficiently pushed out to the object side, and the diameter of the zooming portion entrance determined by the telephoto end F-number light beam increases, leading to an increase in the size of the lens. It is not preferable.

More preferably, conditional expression (5) is more preferably set as follows.
0.35 <| Ok / D1 | <1.35 (5a)
More preferably, conditional expression (5) is
0.4 <| Ok / D1 | <1.2 (5aa)
Is more preferable.

Furthermore, in the zoom lens according to the present invention, in the sub lens group having positive refractive power included in the first lens group, the average Abbe number of the material forming the lens having positive refractive power is ν1p, and the lens having negative refractive power When the average Abbe number of the material forming is ν1n,
30 <ν1p−ν1n <85 (6)
It is more preferable that the following conditional expression is satisfied. Conditional expression (6) defines the primary chromatic aberration correction capability in the sub lens group having a positive refractive index included in the first lens group.

Here, the Abbe number of the optical material is as follows. When the refractive indexes of the Fraunhofer line for the F line (486.1 nm), d line (587.6 nm), and C line (656.3 nm) are NF, Nd, and NC, respectively, the Abbe number νd is ( c) It is represented by the formula.
νd = (Nd−1) / (NF-NC) (c)

Chromatic aberration correction conditions for a thin-walled system (synthetic refractive power φ) composed of two lenses G1 and G2 having a refractive power of φ1 and φ2 and an Abbe number of a material of ν1 and ν2 are the following (d) and (e ).
φ1 / ν1 + φ2 / ν2 = 0 (d)
φ = φ1 + φ2 (e)

When the formula (d) is satisfied, as shown in FIG. 20, the imaging positions of the C-line and F-line light coincide, and the refractive powers φ1 and φ2 at this time are expressed by the following formulas.
φ1 = φ · ν1 / (ν1−ν2) (f)
φ2 = −φ · ν2 / (ν1−ν2) (g)

  As shown in FIG. 20, by using a material having a large Abbe number νdp as the lens G1 having a positive refractive power and a material having a small Abbe number νdn as the lens G2 having a negative refractive power, the unit LP having a positive refractive power is improved. Chromatic aberration correction can be achieved.

  From the above description, in order to satisfactorily correct the axial chromatic aberration particularly conspicuous in the telephoto zoom lens in the sub lens group having positive refractive power included in the first lens group of the zoom lens of the present invention, positive refraction is required. It can be seen that the power lens may be made of a low dispersion material and the negative power lens may be made of a high dispersion material.

  A combination of positive and negative lens materials exceeding the upper limit of conditional expression (6) is not practical because it is very rare in the range of optical materials that are normally used. Exceeding the lower limit of conditional expression (6) is not preferable because it is difficult to obtain a satisfactory chromatic aberration correction effect from the above description.

More preferably, conditional expression (6) is more preferably set as follows.
35 <ν1p−ν1n <80 (6a)
More preferably, conditional expression (6) is
40 <ν1p−ν1n <75 (6aa)
Is more preferable.

Furthermore, in the imaging device having the zoom lens and the camera device of the present invention, when the diagonal length of the effective screen of the imaging device of the imaging device is IS,
8.0 <ft / IS <50.0 (7)
It is more preferable to satisfy the following conditional expression. Conditional expression (7) defines the ratio of the focal length ft in the telephoto end state of the entire lens system and the diagonal length IS of the effective screen of the image sensor. When the upper limit of the conditional expression (7) is exceeded, a system in which the diagonal length of the effective screen of the image sensor is relatively small is assumed, which is excessive with respect to the off-axis aberration fluctuation during focus adjustment, which is the subject of the present invention. May provide a correction technique. If the lower limit of conditional expression (7) is exceeded, a system with a short telephoto end focal length is assumed, and the configuration of the first lens group assumed in the present invention becomes unnecessary or inappropriate, which is not preferable.

More preferably, conditional expression (7) is more preferably set as follows.
9.0 <ft / Ld <45.0 (7a)
More preferably, conditional expression (7) is
10.0 <ft / Ld <40.0 (7aa)
Is more preferable.

  The lens configurations of Examples 1 to 6, which are specific configurations of the zoom lens according to the present invention, will be described below with reference to corresponding Numerical Examples 1 to 6.

  2A and 2B show a zoom lens according to Embodiment 1 (Numerical Embodiment 1) of the present invention. FIG. 2A is a lens cross-sectional view in a state where an object at infinity is in focus at the wide-angle end, and FIG. It is lens sectional drawing of the state which has focused on the object of (3.0m). In the lens cross-sectional views of each example, the left side is the object (subject) side, and the right side is the image side.

  The zoom lens of the present embodiment includes, in order from the object side to the image side, a first lens unit U1 having a positive refractive power that does not move during zooming, a second lens unit U2 having a negative refractive power that moves on the optical axis during zooming, The zoom lens includes a third lens unit U3 having positive refractive power that moves during zooming, an aperture stop SP, and a fourth lens unit U4 (imaging lens group) having positive refractive power that does not move in the optical axis direction.

  The first lens group U1 includes a focus adjustment lens group. The second lens unit U2 includes a zooming lens unit, and performs zooming from the wide-angle end to the telephoto end by moving the optical axis to the image plane side. The third lens unit U3 moves non-linearly on the optical axis in order to correct image plane fluctuations accompanying zooming during zooming from the wide-angle end to the telephoto end. In this embodiment, the second lens unit U2 and the third lens unit U3 constitute a variable magnification optical system. I is an image pickup surface, which corresponds to the image pickup surface of a solid-state image pickup device (photoelectric conversion device) that receives an image formed by a zoom lens and performs photoelectric conversion.

  The zoom lens of each embodiment adopts a zoom type suitable for achieving high magnification and telephoto zooming with good optical performance.

  Next, the first lens unit U1 in the present embodiment will be described. The first lens unit U1 corresponds to the first surface to the fourteenth surface. The first lens unit U1 includes an eleventh lens unit U11 having a positive refractive power that does not move for focus adjustment, a twelfth lens unit U12 having a positive refractive power that moves during focus adjustment, and a negative refraction that moves during focus adjustment. It consists of a thirteenth lens unit U13. The eleventh lens unit U11 corresponds to the first to sixth surfaces, and is composed of two lenses having a positive refractive power and a lens having a negative refractive power in order from the object side to the image side. The twelfth lens unit U12 corresponds to the seventh to eleventh surfaces, and includes a lens having a positive refractive power and a cemented lens of a lens having a positive refractive power and a lens having a negative refractive power. The thirteenth lens group corresponds to the twelfth to fourteenth surfaces and is composed of a cemented lens of a lens having a positive refractive power and a lens having a negative refractive power. As the twelfth lens unit U12 moves on the optical axis from the image side to the object side during focus adjustment from infinity to the closest distance, the thirteenth lens unit U13 moves to the object side.

  In this embodiment, the lenses included in the twelfth lens group U12 and the thirteenth lens group U13 are cemented. However, if each group has appropriate refractive power and chromatic aberration correction capability, they are separated even if they are not cemented. It may be. These are within the assumption of deformation and change as the lens shape in the present invention, and the same applies to all the following embodiments.

  In this embodiment, among the sub-lens groups constituting the first lens group and moving on the optical axis during focus adjustment, the focus adjustment is performed with reference to the position at the time of focusing on infinity. The lens group with the largest driving amount is the twelfth lens group, and the lens group with the second largest driving amount is the thirteenth lens group. Therefore, in this embodiment, the focal length f1P and the maximum movement amount δ1P in the expressions (1) and (2) correspond to the twelfth lens group, and the focal length f1S and the maximum movement amount δ1S correspond to the thirteenth lens group. Is.

  Further, in the present embodiment, the values of δ1P and δ1S are close end values, but these values are not necessarily close end values. It is sufficiently possible to draw a non-linear trajectory in the intermediate region from infinity to the close and exhibit the floating effect. Furthermore, the floating locus may have a plurality of inflection points on the object side or the image side. These can be said to be within the assumption of the deformation and change of the floating mode suitable for implementation as long as the locus is not difficult on the manufacturing surface and the control surface while exhibiting the effect of correcting off-axis aberration which is the main object of the present invention.

  3A, 3 </ b> B, and 3 </ b> C are in focus at (A) infinity, (B) 10.0 m, and (C) close to (3.0 m) at the wide-angle end of Numerical Example 1. It is lens sectional drawing. However, the focal length and the object distance are values when the values of the numerical examples are expressed in mm. This is the same in all the following embodiments.

  4A, 4 </ b> B, and 4 </ b> C are in focus at (A) infinity, (B) 10.0 m, and (C) close to (3.0 m) at the telephoto end of Numerical Example 1. FIG. It is lens sectional drawing.

  In the longitudinal aberration diagram, spherical aberration indicates e-line (solid line), g-line (dotted line), and C-line (dashed line). Astigmatism indicates the e-line meridional image plane (meri) (dotted line) and the sagittal image plane (sagi) (solid line). The lateral chromatic aberration is represented by the g-line (dotted line) and the C-line (dashed line). Fno represents an F number, and ω represents a shooting half angle of view.

  In the longitudinal aberration diagram, the spherical aberration is drawn on a scale of 0.5 mm, the astigmatism is 0.5 mm, the distortion is 5.0%, and the lateral chromatic aberration is drawn on a scale of 0.1 mm. In each of the following embodiments, the wide-angle end and the telephoto end indicate zoom positions when the second lens unit U2 for zooming is located at both ends of a range that can move on the optical axis with respect to the mechanism.

  Table 1 shows values corresponding to the conditional expressions of this example. In this example, the conditional expressions (1) to (7) are satisfied, and the configuration and paraxial arrangement of the first lens unit, and the movement amounts of the twelfth lens unit U12 and the thirteenth lens unit U13 during the focus adjustment are set. By properly setting, the field curvature fluctuation accompanying the focus adjustment on the telephoto side is corrected satisfactorily. As a result, downsizing is achieved while having high optical performance in the entire zoom region and the entire focus region.

  Numerical examples 1 to 6 corresponding to the first to sixth embodiments of the present invention are shown below. In each numerical example, i indicates the order of the surfaces from the object side. ri is the radius of curvature of the i-th surface from the object side, di is the i-th and i + 1-th distance from the object side, and ndi and νdi are the refractive index and Abbe number of the i-th optical member. BF is an air equivalent back focus. The focus movement amount is the amount of movement to the image side if the sign is positive, and to the object side if the sign is negative, based on the state of focusing on the object at infinity. In the locus of focus adjustment from infinity to the closest distance, if there is a movement amount in both positive and negative directions, the larger movement amount from the infinity position is described.

The aspherical shape is the X axis in the optical axis direction, the H axis in the direction perpendicular to the optical axis, the light traveling direction is positive, R is the paraxial radius of curvature, k is the cone constant, A4, A6, A8, A10, A12. When each aspheric coefficient is used, it is expressed by the following equation. “E-Z” means “× 10 ^−Z ”.

(Numerical example 1)
Unit mm

Surface data surface number rd nd vd Effective diameter
1 177.323 12.59 1.49700 81.5 115.38
2 -3740.642 0.20 114.82
3 159.830 12.52 1.49700 81.5 111.03
4 1657.409 5.00 109.36
5 -752.660 2.50 1.85026 32.3 107.82
6 -3119.033 14.16 106.66
7 208.888 12.32 1.59522 67.7 94.74
8 -1667.698 0.50 91.33
9 141.398 11.24 1.49700 81.5 84.01
10 -525.271 2.00 1.83400 37.2 81.21
11 319.655 2.19 77.44
12 514.660 6.30 1.72047 34.7 76.17
13 -347.632 2.00 1.81600 46.6 74.38
14 104.638 (variable) 68.80
15 193.039 1.50 1.77250 49.6 40.31
16 82.681 3.31 39.31
17 -304.014 1.40 1.59522 67.7 39.24
18 47.235 0.25 38.58
19 46.358 4.27 1.80518 25.4 38.72
20 137.504 3.85 38.43
21 -84.999 1.30 1.59522 67.7 38.39
22 135.703 (variable) 38.89
23 581.424 4.58 1.59522 67.7 44.26
24 -91.455 0.30 44.53
25 99.972 6.59 1.49700 81.5 44.54
26 -97.413 1.40 1.83400 37.2 44.32
27 356.906 (variable) 44.16
28 (Aperture) ∞ 1.50 44.21
29 52.500 5.80 1.49700 81.5 44.48
30 385.515 0.20 44.07
31 72.495 6.03 1.49700 81.5 43.05
32 -184.133 4.50 42.37
33 -140.537 1.80 1.81600 46.6 38.67
34 140.367 35.70 37.37
35 198.548 1.80 1.77250 49.6 26.28
36 69.116 5.00 1.59551 39.2 25.67
37 -63.399 1.00 25.11
38 -61.715 1.80 1.81600 46.6 24.45
39 -200.130 27.00 24.07
40 -28.913 1.50 1.81600 46.6 24.90
41 96.354 3.71 1.71736 29.5 27.20
42 -82.767 0.20 27.95
43 136.023 4.69 1.49700 81.5 29.22
44 -60.508 65.16 29.84
Image plane ∞

Various data Zoom ratio 3.00

Focal length 200.00 340.00 600.00
F number 4.60 4.60 5.20
Angle of View 6.18 3.64 2.07
Image height 21.65 21.65 21.65
Total lens length 355.16 355.16 355.16
BF 65.16 65.16 65.16

d14 2.14 40.53 65.62
d22 49.44 33.28 1.25
d27 23.92 1.70 8.63

Entrance pupil position 247.56 456.53 662.57
Exit pupil position -70.77 -70.77 -70.77
Front principal point position 153.30 -53.89 -1385.78
Rear principal point position -134.84 -274.84 -534.84

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 252.24 83.52 -66.85 -97.38
2 15 -48.65 15.87 8.22 -3.70
3 23 142.51 12.87 -1.52 -9.58
4 28 156.89 102.23 -75.86 -121.91

Single lens Data lens Start surface Focal length
1 1 340.01
2 3 353.89
3 5 -1158.84
4 7 311.55
5 9 224.77
6 10 -236.51
7 12 286.92
8 13 -97.87
9 15 -187.44
10 17 -68.34
11 19 84.29
12 21 -87.30
13 23 132.64
14 25 100.09
15 26 -91.05
16 29 121.23
17 31 105.18
18 33 -85.38
19 35 -137.43
20 36 55.99
21 38 -109.44
22 40 -26.97
23 41 62.11
24 43 84.69

Focus movement amount δ1P (12th lens group) -12.633
δ1S (13th lens group) -2.645

  5A and 5B show a zoom lens according to Embodiment 2 (Numerical Embodiment 2) of the present invention. FIG. 5A is a lens cross-sectional view in a state where an object at infinity is in focus at the wide-angle end, and FIG. It is lens sectional drawing of the state which has focused on the object of (4.0 m).

  The zoom lens of the present embodiment includes, in order from the object side to the image side, a first lens unit U1 having a positive refractive power that does not move during zooming, a second lens unit U2 having a negative refractive power that moves on the optical axis during zooming, Third lens unit U3 having positive refractive power that moves during zooming, fourth lens unit U4 having positive refractive power that moves during zooming, aperture stop SP, and fifth lens having positive refractive power that does not move in the optical axis direction It has a group U5 (imaging lens group).

  In this embodiment, the second lens unit U2, the third lens unit U3, and the fourth lens unit U4 constitute a variable magnification optical system.

  In Numerical Example 2, the first surface and the second surface are dummy flat plates assuming a protective glass and the like, and do not move during focus adjustment. In addition to the second embodiment, as an actual product form, protective glass and filters may be attached to and detached from the object side and the image side of the zoom lens of the present invention. Even if the protective glass or the like has a very gentle curvature due to manufacturing accuracy or the like, the change of the application form of the present invention is assumed within a range that does not fail in comparison with various conditions of the present invention.

  The first lens unit U1 corresponds to the third surface to the sixteenth surface. The first lens unit U1 includes an eleventh lens unit U11 having a positive refractive power that moves during focus adjustment, a twelfth lens unit U12 having a positive refractive power that moves during focus adjustment, and a negative refraction that does not move for focus adjustment. It consists of a thirteenth lens unit U13. The eleventh lens unit U11 corresponds to the third to eighth surfaces, and is composed of two lenses having a positive refractive power and a lens having a negative refractive power in order from the object side to the image side. The twelfth lens unit U12 corresponds to the ninth to thirteenth surfaces, and includes a lens having a positive refractive power, and a cemented lens of a lens having a positive refractive power and a lens having a negative refractive power. The thirteenth lens group corresponds to the fourteenth through sixteenth surfaces and is composed of a cemented lens of a lens having a positive refractive power and a lens having a negative refractive power. The eleventh lens unit U11 moves to the image side as the twelfth lens unit U12 moves on the optical axis from the image side to the object side during focus adjustment from infinity to the close.

  6 (A), 6 (B), and 6 (C) are those when focusing on (A) infinity, (B) 40.0m, and (C) closest (4.0m) at the wide angle end of Numerical Example 2. FIG. It is lens sectional drawing.

  FIGS. 7A, 7B, and 7C are obtained when the telephoto end of Numerical Example 2 is in focus at (A) infinity, (B) 40.0 m, and (C) close to (4.0 m). It is lens sectional drawing.

  In this embodiment, among the sub-lens groups constituting the first lens group and moving on the optical axis during focus adjustment, the focus adjustment is performed with reference to the position at the time of focusing on infinity. The lens group with the largest driving amount is the twelfth lens group, and the lens group with the second largest driving amount is the thirteenth lens group. Therefore, in this embodiment, the focal length f1P and the maximum movement amount δ1P in the expressions (1) and (2) correspond to the twelfth lens group, and the focal length f1S and the maximum movement amount δ1S correspond to the thirteenth lens group. Is.

Table 1 shows values corresponding to the conditional expressions of this example. In this example, the conditional expressions (1) to (7) are satisfied, and the configuration and paraxial arrangement of the first lens group, and the movement amounts of the twelfth lens group and the eleventh lens group at the time of focus adjustment are appropriately set. By setting, the field curvature fluctuation accompanying the focus adjustment on the telephoto side is corrected well. As a result, downsizing is achieved while having high optical performance in the entire zoom region and the entire focus region.

(Numerical example 2)
Unit mm

Surface data surface number rd nd vd Effective diameter
1 ∞ 5.00 1.51633 64.1 143.01
2 ∞ 1.99 141.01
3 255.322 17.04 1.43387 95.1 138.81
4 -614.755 0.70 138.21
5 226.984 19.23 1.43387 95.1 133.12
6 -388.226 0.18 131.57
7 -410.631 3.90 1.90270 31.0 131.13
8 2106.848 24.70 128.72
9 329.302 8.08 1.43387 95.1 117.08
10 10274.587 0.20 115.91
11 233.822 11.37 1.43875 94.9 112.04
12 -1009.394 3.30 1.83400 37.2 110.39
13 2967.518 1.82 108.31
14 2187.561 7.45 1.76182 26.5 106.88
15 -334.550 3.00 1.64000 60.1 105.81
16 293.633 (variable) 100.33
17 293.659 1.80 1.81600 46.6 43.71
18 39.911 8.47 39.27
19 -63.678 1.50 1.49700 81.5 39.18
20 333.424 0.10 38.93
21 68.047 7.91 1.72047 34.7 38.90
22 -60.297 1.50 1.49700 81.5 38.40
23 81.183 0.10 35.68
24 50.808 2.68 1.72047 34.7 35.19
25 65.220 5.50 34.22
26 -50.061 1.40 1.49700 81.5 34.10
27 137.710 (variable) 33.67
28 101.899 8.12 1.49700 81.5 46.90
29 -86.087 0.20 47.24
30 -142.804 1.50 1.72047 34.7 47.19
31 * 541.644 0.20 47.71
32 78.082 8.00 1.43875 94.9 48.91
33 -146.898 (variable) 48.99
34 81.999 7.70 1.43875 94.9 48.24
35 -141.057 0.20 47.74
36 53.308 1.50 1.72047 34.7 44.05
37 33.102 0.95 41.33
38 36.138 6.64 1.49700 81.5 41.31
39 138.501 (variable) 40.49
40 (Aperture) ∞ 2.31 21.98
41 -152.495 1.40 1.88300 40.8 20.78
42 28.188 4.02 1.71736 29.5 19.90
43 -67.394 3.70 19.60
44 -288.739 1.40 1.83481 42.7 17.08
45 28.092 0.15 16.31
46 23.229 3.28 1.71736 29.5 16.31
47 36.407 0.84 15.47
48 90.576 1.50 1.88300 40.8 15.39
49 50.475 40.00 15.04
50 128.302 5.84 1.43875 94.9 28.12
51 -32.053 1.20 1.83481 42.7 28.39
52 392.250 0.50 29.97
53 161.204 1.20 1.83481 42.7 30.64
54 31.390 7.41 1.58144 40.8 31.96
55 -101.674 1.37 32.90
56 45.487 8.51 1.51633 64.1 37.59
57 -71.324 41.87 37.76
Image plane ∞

Aspheric data 31st surface
K = 0.00000e + 000 A 4 = 1.02282e-006 A 6 = 1.56032e-010
A 8 = -1.04070e-013 A10 = 2.20331e-016 A12 = -1.29657e-019

Various data Zoom ratio 20.00

Focal length 50.00 200.00 1000.00
F number 4.70 4.70 7.20
Angle of view 17.28 4.45 0.89
Image height 15.55 15.55 15.55
Total lens length 469.00 469.00 469.00
BF 41.87 41.87 41.87

d16 3.00 78.14 129.00
d27 140.22 56.71 0.78
d33 22.07 13.35 11.46
d39 3.29 20.38 27.35

Entrance pupil position 201.44 697.73 3824.96
Exit pupil position -500.39 -500.39 -500.39
Front principal point position 246.83 823.96 2980.81
Rear principal point position -8.13 -158.14 -958.13

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 254.98 107.96 9.22 -70.04
2 17 -30.00 30.95 9.59 -11.18
3 28 80.20 18.02 5.45 -7.09
4 34 93.83 16.99 1.22 -10.44
5 40 213.32 84.63 173.40 426.29

Single lens Data lens Start surface Focal length
1 1 0.00
2 3 417.22
3 5 332.46
4 7 -377.53
5 9 781.96
6 11 432.82
7 12 -897.05
8 14 378.02
9 15 -242.92
10 17 -56.50
11 19 -107.13
12 21 45.24
13 22 -69.17
14 24 294.01
15 26 -73.47
16 28 94.98
17 30 -155.65
18 32 117.18
19 34 119.15
20 36 -124.28
21 38 96.02
22 41 -26.69
23 42 27.98
24 44 -30.44
25 46 80.36
26 48 -130.67
27 50 58.96
28 51 -35.25
29 53 -46.63
30 54 41.87
31 56 54.96

Focus movement amount δ1P (12th lens group) -17.768
δ1S (11th lens group) 6.627

  8A and 8B show a zoom lens according to Embodiment 3 (Numerical Embodiment 3) of the present invention. FIG. 8A is a lens cross-sectional view in a state where an object at infinity is in focus at the wide-angle end, and FIG. It is lens sectional drawing of the state which has focused on the object of (4.0 m).

  The zoom lens of the present embodiment includes, in order from the object side to the image side, a first lens unit U1 having a positive refractive power that does not move during zooming, a second lens unit U2 having a negative refractive power that moves on the optical axis during zooming, The third lens unit U3 having positive refractive power that moves during zooming, the fourth lens unit U4 having positive refractive power that moves during zooming, the aperture stop SP, and the fifth lens having negative refractive power that does not move in the optical axis direction It has a group U5 (imaging lens group).

  In this embodiment, the second lens group, the third lens group, and the fourth lens group constitute a variable magnification optical system.

  The first lens unit U1 corresponds to the first surface to the fourteenth surface. The first lens unit U1 includes an eleventh lens unit U11 having a positive refractive power that does not move for focus adjustment, a twelfth lens unit U12 having a positive refractive power that moves during focus adjustment, and a negative refraction that moves during focus adjustment. It consists of a thirteenth lens unit U13. The eleventh lens unit U11 corresponds to the first to sixth surfaces, and is composed of two lenses having a positive refractive power and a lens having a negative refractive power in order from the object side to the image side. The twelfth lens unit U12 corresponds to the seventh to eleventh surfaces, and includes a lens having a positive refractive power and a cemented lens of a lens having a positive refractive power and a lens having a negative refractive power. The thirteenth lens group corresponds to the twelfth to fourteenth surfaces and is composed of a cemented lens of a lens having a positive refractive power and a lens having a negative refractive power. The twelfth lens unit U12 moves to the image side as the thirteenth lens unit U13 moves on the optical axis from the object side to the image side during focus adjustment from infinity to the close range.

  FIGS. 9A, 9B, and 9C show the results of focusing on (A) infinity, (B) 10.0 m, and (C) close to (4.0 m) at the wide angle end of Numerical Example 3. It is lens sectional drawing.

  FIGS. 10A, 10B, and 10C are obtained when the telephoto end of Numerical Example 3 is in focus at (A) infinity, (B) 10.0 m, (C) close to (4.0 m). It is lens sectional drawing.

  In this embodiment, among the sub-lens groups constituting the first lens group and moving on the optical axis during focus adjustment, the focus adjustment is performed with reference to the position at the time of focusing on infinity. The lens group with the largest driving amount is the thirteenth lens group, and the lens group with the second largest driving amount is the twelfth lens group. Therefore, in this embodiment, the focal length f1P and the maximum movement amount δ1P in the expressions (1) and (2) correspond to the thirteenth lens group, and the focal length f1S and the maximum movement amount δ1S correspond to the twelfth lens group. Is.

Table 1 shows values corresponding to the conditional expressions of this example. In this example, the conditional expressions (1) to (7) are satisfied, and the configuration and paraxial arrangement of the first lens group, and the movement amounts of the thirteenth lens group and the twelfth lens group at the time of focus adjustment are appropriately set. By setting, the field curvature fluctuation accompanying the focus adjustment on the telephoto side is corrected well. As a result, downsizing is achieved while having high optical performance in the entire zoom region and the entire focus region.

(Numerical Example 3)
Unit mm

Surface data surface number rd nd vd Effective diameter
1 823.736 6.92 1.49700 81.5 120.12
2 -1045.672 0.20 118.53
3 1827.719 9.90 1.49700 81.5 116.02
4 -284.302 1.00 114.13
5 -252.158 2.50 2.00069 25.5 113.75
6 -394.652 0.97 112.80
7 193.353 9.40 1.43387 95.1 106.20
8 2642.673 0.20 105.31
9 121.367 15.38 1.43875 94.9 100.02
10 -632.145 2.40 1.90270 31.0 98.35
11 -2288.352 1.00 96.85
12 346.384 6.50 1.95906 17.5 93.21
13 -1139.273 2.30 2.00069 25.5 91.95
14 204.836 (variable) 87.88
15 * -1913.605 1.20 1.81600 46.6 40.72
16 38.869 8.28 36.52
17 -49.021 1.20 1.49700 81.5 36.42
18 223.364 0.10 36.38
19 92.824 6.78 1.72047 34.7 36.46
20 -49.645 1.20 1.49700 81.5 36.27
21 96.563 0.10 34.57
22 52.642 2.45 1.72047 34.7 34.76
23 76.977 3.68 34.59
24 -96.668 1.20 1.49700 81.5 34.61
25 201.488 (variable) 35.34
26 367.370 6.10 1.51633 64.1 40.29
27 -53.037 0.20 40.63
28 -52.576 1.00 1.72047 34.7 40.62
29 * -837.552 0.20 42.12
30 93.525 7.40 1.49700 81.5 43.69
31 -83.168 (variable) 44.02
32 180.987 5.45 1.43875 94.9 44.06
33 -115.373 0.20 43.92
34 52.340 1.00 1.72047 34.7 42.03
35 28.905 0.64 39.69
36 29.220 10.13 1.51633 64.1 39.98
37 -285.997 (variable) 39.43
38 (Aperture) ∞ 5.73 29.81
39 -74.506 1.00 1.88300 40.8 26.91
40 44.552 5.47 1.72825 28.5 26.31
41 -60.052 1.45 26.10
42 1230.070 1.00 1.83481 42.7 24.53
43 48.784 0.50 23.82
44 25.567 4.43 1.71736 29.5 23.59
45 83.265 0.30 22.45
46 79.674 1.00 1.88300 40.8 22.24
47 29.066 35.00 21.19
48 -142.723 7.27 1.43875 94.9 27.88
49 -21.280 1.00 1.88300 40.8 28.44
50 -31.158 9.42 29.91
51 -38.902 1.00 1.88300 40.8 31.08
52 91.110 8.00 1.51742 52.4 33.77
53 -48.767 2.25 35.87
54 54.003 6.83 1.58913 61.1 42.40
55 -456.086 43.00 42.49
Image plane ∞

Aspheric data 15th surface
K = 7.19010e + 003 A 4 = -2.10972e-007 A 6 = 6.44507e-010
A 8 = -3.67195e-012 A10 = 9.99355e-015 A12 = -8.37844e-018

29th page
K = 6.19752e + 002 A 4 = 9.60513e-007 A 6 = 2.10993e-010
A 8 = 2.92701e-013 A10 = -1.28224e-015 A12 = 1.62294e-018

Various data Zoom ratio 10.00

Focal length 60.00 120.00 600.00
F number 4.50 4.50 5.58
Angle of View 19.83 10.22 2.07
Image height 21.64 21.64 21.64
Total lens length 384.90 384.90 384.90
BF 43.00 43.00 43.00

d14 17.21 49.72 104.93
d25 96.24 57.38 1.96
d31 18.13 17.09 11.59
d37 1.50 8.90 14.61

Entrance pupil position 145.02 282.86 1348.51
Exit pupil position -133.48 -133.48 -133.48
Front principal point position 184.62 321.25 -91.41
Rear principal point position -17.00 -77.02 -557.00

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 191.58 58.68 3.18 -33.53
2 15 -30.41 26.20 4.95 -13.71
3 26 105.85 14.89 7.54 -2.52
4 32 69.44 17.41 4.79 -7.24
5 38 -121.63 91.63 -30.22 -173.68

Single lens Data lens Start surface Focal length
1 1 925.53
2 3 494.36
3 5 -697.64
4 7 479.07
5 9 232.93
6 10 -960.91
7 12 273.90
8 13 -171.76
9 15 -46.44
10 17 -80.53
11 19 45.50
12 20 -65.60
13 22 220.21
14 24 -130.88
15 26 89.87
16 28 -77.38
17 30 89.56
18 32 161.09
19 34 -90.62
20 36 51.72
21 39 -31.27
22 40 35.62
23 42 -60.54
24 44 49.43
25 46 -52.01
26 48 55.84
27 49 -79.35
28 51 -30.58
29 52 62.33
30 54 82.05

Focus movement amount δ1P (13th lens group) 14.591
δ1S (12th lens group) 1.292

  11A and 11B show a zoom lens according to Embodiment 4 (Numerical Embodiment 4) of the present invention. FIG. 11A is a lens cross-sectional view in a state where an object at infinity is in focus at the wide-angle end, and FIG. It is lens sectional drawing of the state which has focused on the object of (4.0 m).

  The zoom lens of the present embodiment includes, in order from the object side to the image side, a first lens unit U1 having a positive refractive power that does not move during zooming, a second lens unit U2 having a negative refractive power that moves on the optical axis during zooming, The third lens unit U3 having positive refractive power that moves during zooming, the fourth lens unit U4 having positive refractive power that moves during zooming, the aperture stop SP, and the fifth lens having negative refractive power that does not move in the optical axis direction It has a group U5 (imaging lens group).

  In this embodiment, the second lens unit U2, the third lens unit U3, and the fourth lens unit U4 constitute a variable magnification optical system.

  The first lens unit U1 corresponds to the first surface to the fifteenth surface. The first lens unit U1 includes an eleventh lens unit U11 having a positive refractive power that moves during focus adjustment, a twelfth lens unit U12 having a negative refractive power that does not move for focus adjustment, and a negative refraction that moves during focus adjustment. It consists of a thirteenth lens unit U13. The eleventh lens unit U11 corresponds to the first surface to the tenth surface, and in order from the object side to the image side, two positive refractive power lenses, a negative refractive power lens, and two positive refractive power lenses. It consists of a lens. The twelfth lens unit U12 corresponds to the eleventh surface to the twelfth surface, and includes a lens having a negative refractive power. Unlike the first to third embodiments, the twelfth lens unit U12 is a lens unit having a negative refractive power. However, the twelfth lens unit U12 can be negative depending on the division method in designing the lens of the first lens unit U1. It is an example which shows. The thirteenth lens group corresponds to the thirteenth to fifteenth surfaces and is composed of a cemented lens of a lens having a positive refractive power and a lens having a negative refractive power. The eleventh lens unit U11 moves to the image side as the thirteenth lens unit U13 moves on the optical axis from the object side to the image side during focus adjustment from infinity to the close range.

  12A, 12 </ b> B, and 12 </ b> C are those when focusing on (A) infinity, (B) 10.0 m, and (C) closest (4.0 m) at the wide-angle end of Numerical Example 4. FIGS. It is lens sectional drawing.

  FIGS. 13A, 13B, and 13C are obtained when the telephoto end of Numerical Example 4 is in focus at (A) infinity, (B) 10.0 m, and (C) close to (4.0 m). It is lens sectional drawing.

  In this embodiment, among the sub-lens groups constituting the first lens group and moving on the optical axis during focus adjustment, the focus adjustment is performed with reference to the position at the time of focusing on infinity. The lens group having the largest drive amount is the thirteenth lens group, and the lens group having the second largest drive amount is the eleventh lens group. Therefore, in this embodiment, the focal length f1P and the maximum movement amount δ1P in the expressions (1) and (2) correspond to the thirteenth lens group, and the focal length f1S and the maximum movement amount δ1S correspond to the eleventh lens group. Is.

Table 1 shows values corresponding to the conditional expressions of this example. In this example, the conditional expressions (1) to (7) are satisfied, and the configuration and paraxial arrangement of the first lens group, and the movement amounts of the eleventh lens group and the thirteenth lens group at the time of focus adjustment are appropriately set. By setting, the field curvature fluctuation accompanying the focus adjustment on the telephoto side is corrected well. As a result, downsizing is achieved while having high optical performance in the entire zoom region and the entire focus region.

(Numerical example 4)
Unit mm

Surface data surface number rd nd vd Effective diameter
1 636.317 6.95 1.49700 81.5 125.43
2 -2301.998 0.20 123.80
3 2001.722 10.66 1.49700 81.5 122.06
4 -280.244 0.87 120.18
5 -254.751 2.50 2.00069 25.5 119.86
6 -390.965 0.50 118.45
7 201.043 9.93 1.43387 95.1 109.14
8 12850.374 0.20 107.51
9 126.151 15.10 1.43875 94.9 101.09
10 -626.792 1.00 99.51
11 -626.596 2.40 1.90270 31.0 98.40
12 -2246.835 1.00 96.82
13 415.373 6.35 1.95906 17.5 93.58
14 -836.180 2.30 2.00069 25.5 92.38
15 230.808 (variable) 88.59
16 * -1001.474 1.20 1.81600 46.6 41.45
17 41.595 8.22 37.26
18 -49.843 1.20 1.49700 81.5 37.15
19 235.502 0.10 36.95
20 90.799 7.01 1.72047 34.7 36.97
21 -49.201 1.20 1.49700 81.5 36.73
22 95.318 0.10 34.71
23 54.760 2.36 1.72047 34.7 34.47
24 78.588 3.75 34.28
25 -87.128 1.20 1.49700 81.5 34.29
26 168.887 (variable) 35.06
27 350.460 6.04 1.51633 64.1 39.86
28 -52.836 0.29 40.21
29 -51.174 1.00 1.72047 34.7 40.20
30 * -1095.119 0.20 41.77
31 107.409 7.22 1.49700 81.5 43.16
32 -76.440 (variable) 43.57
33 158.636 5.06 1.43875 94.9 43.98
34 -123.894 0.20 43.89
35 51.965 1.00 1.72047 34.7 42.26
36 29.418 0.55 40.04
37 29.668 10.23 1.51633 64.1 40.31
38 -245.892 (variable) 39.79
39 (Aperture) ∞ 6.38 30.01
40 -81.805 1.00 1.88300 40.8 26.65
41 40.636 5.51 1.72825 28.5 25.97
42 -62.535 1.45 25.74
43 -9679.995 1.00 1.83481 42.7 24.25
44 48.709 0.50 23.55
45 25.578 4.15 1.71736 29.5 23.35
46 93.888 0.38 22.39
47 105.017 1.00 1.88300 40.8 22.20
48 30.551 35.00 21.17
49 233.816 8.00 1.43875 94.9 28.80
50 -22.788 1.00 1.88300 40.8 29.13
51 -32.823 9.47 30.35
52 -37.717 1.00 1.88300 40.8 30.36
53 135.508 8.00 1.51742 52.4 32.45
54 -78.098 3.88 35.34
55 55.134 6.54 1.58913 61.1 41.72
56 -498.406 40.53 41.83
Image plane ∞

Aspheric data 16th surface
K = 1.66262e + 003 A 4 = -2.78138e-008 A 6 = 3.08177e-010
A 8 = -1.09032e-012 A10 = 2.78474e-015 A12 = -1.62098e-018

30th page
K = 1.11074e + 003 A 4 = 8.99890e-007 A 6 = 1.85889e-010
A 8 = -7.88530e-014 A10 = -4.80667e-016 A12 = 1.01289e-018

Various data Zoom ratio 10.00

Focal length 60.00 240.03 600.00
F number 4.50 4.50 5.53
Angle of View 19.83 5.15 2.07
Image height 21.64 21.64 21.64
Total lens length 385.96 385.96 385.96
BF 40.53 40.53 40.53

d15 17.94 78.99 105.80
d26 94.55 32.80 2.11
d32 19.11 6.72 10.45
d38 1.50 14.59 14.74

Entrance pupil position 149.73 554.54 1353.33
Exit pupil position -120.86 -120.86 -120.86
Front principal point position 187.42 437.59 -277.28
Rear principal point position -19.47 -199.50 -559.47

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 193.73 59.96 3.44 -34.33
2 16 -30.14 26.33 5.53 -13.03
3 27 113.03 14.75 7.86 -2.13
4 33 66.74 17.03 4.50 -7.25
5 39 -104.56 94.25 -18.20 -142.90

Single lens Data lens Start surface Focal length
1 1 1000.91
2 3 493.95
3 5 -730.72
4 7 469.44
5 9 240.22
6 11 -955.97
7 13 286.26
8 14 -178.90
9 16 -48.67
10 18 -82.41
11 20 44.94
12 21 -64.92
13 23 239.03
14 25 -115.13
15 27 89.05
16 29 -74.04
17 31 90.78
18 33 159.02
19 35 -95.24
20 37 51.74
21 40 -30.45
22 41 34.32
23 43 -57.73
24 45 47.41
25 47 -48.82
26 49 47.66
27 50 -88.06
28 52 -33.13
29 53 96.56
30 55 84.31

Focus movement amount δ1P (13th lens group) 17.652
δ1S (11th lens group) 0.721

  14A and 14B show a zoom lens according to Embodiment 5 (Numerical Embodiment 5) of the present invention. FIG. 14A is a lens cross-sectional view in a state where an object at infinity is in focus at the wide-angle end, and FIG. It is lens sectional drawing of the state which has focused on the object of (3.5m).

  The zoom lens of the present embodiment includes, in order from the object side to the image side, a first lens unit U1 having a positive refractive power that does not move during zooming, a second lens unit U2 having a negative refractive power that moves on the optical axis during zooming, Third lens unit U3 having positive refractive power that moves during zooming, fourth lens unit U4 having positive refractive power that moves during zooming, aperture stop SP, and fifth lens having positive refractive power that does not move in the optical axis direction It has a group U5 (imaging lens group).

  In this embodiment, the second lens unit U2, the third lens unit U3, and the fourth lens unit U4 constitute a variable magnification optical system.

  The first lens unit U1 corresponds to the first surface to the seventeenth surface. The first lens unit U1 is an eleventh lens unit U11 having a positive refractive power that does not move during focus adjustment, a twelfth lens unit U12 having a negative refractive power that is moved for focus adjustment, and is moved for focus adjustment. The lens unit includes a thirteenth lens unit U13 having negative refractive power and a fourteenth lens unit U14 having negative refractive power that does not move for focus adjustment. The eleventh lens unit U11 corresponds to the first surface to the sixth surface, and includes a lens having a negative refractive power and two lenses having a positive refractive power in order from the object side to the image side. The twelfth lens unit U12 corresponds to the seventh to ninth surfaces, and is composed of a cemented lens of a lens having a positive refractive power and a lens having a negative refractive power. The thirteenth lens group corresponds to the tenth to fourteenth surfaces and is composed of a cemented lens of a lens having a positive refractive power, a lens having a positive refractive power, and a lens having a negative refractive power. The fourteenth lens unit U14 corresponds to the eleventh surface to the seventeenth surface, and includes a cemented lens of a lens having a positive refractive power and a lens having a negative refractive power. The twelfth lens unit U12 moves to the image side as the thirteenth lens unit U13 moves on the optical axis from the image side to the object side during focus adjustment from infinity to the close.

  FIGS. 15A, 15B, and 15C are obtained when focusing on (A) infinity, (B) 20.0 m, and (C) close to (3.5 m) at the wide angle end of Numerical Example 5. It is lens sectional drawing.

  FIGS. 16A, 16B, and 16C are obtained when the telephoto end of Numerical Example 5 is in focus at (A) infinity, (B) 20.0 m, (C) close to (3.5 m). It is lens sectional drawing.

  In this embodiment, among the sub-lens groups constituting the first lens group and moving on the optical axis during focus adjustment, the focus adjustment is performed with reference to the position at the time of focusing on infinity. The lens group with the largest driving amount is the thirteenth lens group, and the lens group with the second largest driving amount is the twelfth lens group. Therefore, in this embodiment, the focal length f1P and the maximum movement amount δ1P in the expressions (1) and (2) correspond to the thirteenth lens group, and the focal length f1S and the maximum movement amount δ1S correspond to the twelfth lens group. Is.

Table 1 shows values corresponding to the conditional expressions of this example. In this example, the conditional expressions (1) to (7) are satisfied, and the configuration and paraxial arrangement of the first lens group, and the movement amounts of the twelfth lens group and the thirteenth lens group at the time of focus adjustment are appropriately set. By setting, the field curvature fluctuation accompanying the focus adjustment on the telephoto side is corrected well. As a result, downsizing is achieved while having high optical performance in the entire zoom region and the entire focus region.

(Numerical example 5)
Unit mm

Surface data surface number rd nd vd Effective diameter
1 400.000 4.00 1.65412 39.7 146.12
2 317.526 1.62 143.27
3 250.244 16.62 1.43387 95.1 141.28
4 -726.590 0.70 140.22
5 207.160 19.05 1.43387 95.1 132.96
6 -470.495 2.77 131.60
7 -562.701 4.39 1.49700 81.5 128.91
8 -410.631 3.50 1.90270 31.0 127.73
9 4293.202 19.54 125.71
10 * 349.974 8.03 1.43387 95.1 115.93
11 2242.853 0.20 114.40
12 237.387 11.26 1.43875 94.9 111.13
13 -1098.499 3.30 1.83400 37.2 109.41
14 3717.876 3.28 107.50
15 4017.277 8.26 1.76182 26.5 105.24
16 -315.972 3.00 1.64000 60.1 103.82
17 325.553 (variable) 98.81
18 314.611 1.80 1.81600 46.6 45.79
19 39.340 10.30 40.84
20 -74.802 1.50 1.49700 81.5 40.11
21 189.003 0.10 39.77
22 66.960 10.41 1.72047 34.7 39.79
23 -67.911 1.50 1.49700 81.5 38.62
24 82.421 0.10 36.14
25 48.849 2.81 1.72047 34.7 35.61
26 64.729 5.56 34.64
27 -51.939 1.40 1.49700 81.5 34.51
28 153.221 (variable) 34.04
29 110.629 7.40 1.49700 81.5 46.66
30 -82.902 0.20 46.91
31 -114.479 1.50 1.72047 34.7 46.87
32 * 3512.529 0.20 47.52
33 66.368 8.35 1.43875 94.9 49.15
34 -185.420 (variable) 49.15
35 68.183 7.61 1.43875 94.9 48.04
36 -232.961 0.20 47.41
37 52.010 1.50 1.72047 34.7 43.90
38 31.569 1.62 40.93
39 37.302 7.87 1.49700 81.5 40.92
40 282.651 (variable) 39.75
41 (Aperture) ∞ 2.44 21.77
42 -99.833 1.40 1.88300 40.8 20.53
43 23.139 5.14 1.71736 29.5 19.59
44 -48.420 3.67 19.26
45 -117.000 1.40 1.83481 42.7 16.59
46 29.663 0.15 15.88
47 21.984 3.24 1.71736 29.5 15.87
48 31.275 2.44 15.01
49 83.372 1.50 1.88300 40.8 14.63
50 46.310 40.00 14.71
51 55.114 7.70 1.43875 94.9 31.19
52 -35.082 1.20 1.83481 42.7 31.33
53 33232.005 0.68 32.68
54 159.726 1.20 1.83481 42.7 33.49
55 30.902 7.52 1.58144 40.8 34.46
56 -273.987 0.57 35.23
57 41.806 8.73 1.51633 64.1 39.22
58 -99.951 41.89 39.25
Image plane ∞

Aspheric data 10th surface
K = 0.00000e + 000 A 4 = -4.27556e-009 A 6 = 3.44723e-013
A 8 = -3.39221e-016 A10 = 9.08206e-020 A12 = -8.98950e-024

32nd page
K = 0.00000e + 000 A 4 = 9.54471e-007 A 6 = 2.42301e-011
A 8 = 4.58696e-013 A10 = -6.54609e-016 A12 = 3.94910e-019

Various data Zoom ratio 20.00

Focal length 50.00 200.00 1000.00
F number 4.70 4.70 7.24
Angle of view 17.28 4.45 0.89
Image height 15.55 15.55 15.55
Total lens length 477.60 477.60 477.60
BF 41.89 41.89 41.89

d17 2.52 77.97 128.94
d28 142.08 57.66 0.88
d34 16.70 11.04 11.66
d40 3.97 18.59 23.80

Entrance pupil position 205.95 714.53 3863.91
Exit pupil position -633.50 -633.50 -633.50
Front principal point position 252.25 855.31 3383.28
Rear principal point position -8.11 -158.11 -958.11

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 258.09 109.52 6.20 -72.91
2 18 -30.21 35.49 10.12 -13.13
3 29 79.38 17.66 5.16 -7.09
4 35 90.22 18.80 2.35 -10.92
5 41 179.21 88.97 152.55 391.96

Single lens Data lens Start surface Focal length
1 1 -2386.29
2 3 430.16
3 5 333.52
4 7 3019.35
5 8 -411.89
6 10 952.15
7 12 444.94
8 13 -1009.97
9 15 381.44
10 16 -249.09
11 18 -54.98
12 20 -107.31
13 22 48.04
14 23 -74.45
15 25 255.48
16 27 -77.64
17 29 96.30
18 31 -152.81
19 33 112.25
20 35 120.85
21 37 -114.26
22 39 85.30
23 42 -21.04
24 43 22.33
25 45 -28.07
26 47 89.26
27 49 -119.57
28 51 50.04
29 52 -41.75
30 54 -45.84
31 55 47.92
32 57 58.10

Focus movement amount δ1P (13th lens group) -17.226
δ1S (12th lens group) 2.274

  17A and 17B show a zoom lens according to Embodiment 6 (Numerical Embodiment 6) of the present invention. FIG. 17A is a lens cross-sectional view in a state where an object at infinity is in focus at the wide angle end, and FIG. It is lens sectional drawing of the state which has focused on the object of (4.0 m).

  The zoom lens of the present embodiment includes, in order from the object side to the image side, a first lens unit U1 having a positive refractive power that does not move during zooming, a second lens unit U2 having a negative refractive power that moves on the optical axis during zooming, Third lens unit U3 having positive refractive power that moves during zooming, fourth lens unit U4 having positive refractive power that moves during zooming, aperture stop SP, and fifth lens having positive refractive power that does not move in the optical axis direction It has a group U5 (imaging lens group).

  In this embodiment, the second lens unit U2, the third lens unit U3, and the fourth lens unit U4 constitute a variable magnification optical system.

  The first lens unit U1 corresponds to the first surface to the fourteenth surface. The first lens unit U1 is an eleventh lens unit U11 having a positive refractive power that does not move during focus adjustment, a twelfth lens unit U12 having a positive refractive power that is moved for focus adjustment, and is moved for focus adjustment. The lens unit includes a thirteenth lens unit U13 having a negative refractive power and a fourteenth lens unit U14 having a negative refractive power that moves for focus adjustment. The eleventh lens unit U11 corresponds to the first surface to the second surface, and includes a lens having a positive refractive power. The twelfth lens unit U12 corresponds to the third to sixth surfaces, and includes a lens having a positive refractive power and a lens having a negative refractive power. The thirteenth lens group corresponds to the seventh surface to the eleventh surface, and includes a cemented lens of a lens having a positive refractive power, a lens having a positive refractive power, and a lens having a negative refractive power. The fourteenth lens unit U14 corresponds to the twelfth to fourteenth surfaces, and is composed of a cemented lens of a lens having a positive refractive power and a lens having a negative refractive power. During the focus adjustment from infinity to close, the twelfth lens unit U12 moves on the optical axis from the object side to the image side, the thirteenth lens unit U13 moves from the image side to the object side, and the fourteenth lens unit U14 Moving from the image side to the object side. In the sixth embodiment, the number of driving groups at the time of focus adjustment is increased to three, thereby improving the ability to correct aberration fluctuations during focus adjustment.

  18 (A), (B), and (C) are those when focusing on (A) infinity, (B) 20.0 m, and (C) close to (4.0 m) at the wide angle end of Numerical Example 6. FIG. It is lens sectional drawing.

  FIGS. 19A, 19B, and 19C are obtained when the telephoto end of Numerical Example 6 is in focus at (A) infinity, (B) 20.0 m, and (C) close to (4.0 m). It is lens sectional drawing.

  In this embodiment, among the sub-lens groups constituting the first lens group and moving on the optical axis during focus adjustment, the focus adjustment is performed with reference to the position at the time of focusing on infinity. The lens group with the largest driving amount is the thirteenth lens group, and the lens group with the second largest driving amount is the twelfth lens group. Therefore, in this embodiment, the focal length f1P and the maximum movement amount δ1P in the expressions (1) and (2) correspond to the thirteenth lens group, and the focal length f1S and the maximum movement amount δ1S correspond to the twelfth lens group. Is.

Table 1 shows values corresponding to the conditional expressions of this example. In this embodiment, the conditional expressions (1) to (7) are satisfied, and by setting the configuration and paraxial arrangement of the first lens group and the amount of movement of each lens group at the time of focus adjustment, the telephoto lens is set. The image surface curvature variation due to the focus adjustment on the side is satisfactorily corrected. As a result, downsizing is achieved while having high optical performance in the entire zoom region and the entire focus region.

(Numerical example 6)
Unit mm

Surface data surface number rd nd vd Effective diameter
1 261.766 17.94 1.43387 95.1 138.79
2 -592.570 0.70 138.04
3 227.037 19.49 1.43387 95.1 132.96
4 -387.104 0.39 131.28
5 -410.631 3.90 1.90270 31.0 130.65
6 2304.505 25.09 128.28
7 334.943 8.09 1.43387 95.1 116.40
8 8970.820 0.20 115.16
9 240.229 11.82 1.43875 94.9 111.46
10 -770.013 3.30 1.83400 37.2 109.68
11 2925.332 1.83 107.49
12 1600.154 7.65 1.76182 26.5 105.95
13 -332.389 3.00 1.64000 60.1 104.88
14 292.349 (variable) 99.52
15 292.398 1.80 1.81600 46.6 44.18
16 39.882 8.66 39.61
17 -62.941 1.50 1.49700 81.5 39.52
18 346.762 0.10 39.27
19 68.157 8.02 1.72047 34.7 39.23
20 -60.130 1.50 1.49700 81.5 38.72
21 81.297 0.10 35.93
22 51.341 2.67 1.72047 34.7 35.44
23 65.582 5.52 34.47
24 -50.811 1.40 1.49700 81.5 34.35
25 139.043 (variable) 33.90
26 95.482 7.71 1.49700 81.5 47.29
27 -89.740 0.20 47.53
28 -136.155 1.50 1.72047 34.7 47.48
29 * 712.782 0.20 48.02
30 79.572 7.97 1.43875 94.9 49.23
31 -149.314 (variable) 49.31
32 77.975 7.74 1.43875 94.9 48.62
33 -160.095 0.20 48.10
34 52.988 1.50 1.72047 34.7 44.46
35 32.893 1.11 41.67
36 36.505 6.73 1.49700 81.5 41.65
37 146.203 (variable) 40.83
38 (Aperture) ∞ 2.26 21.88
39 -178.721 1.40 1.88300 40.8 20.69
40 28.391 4.22 1.71736 29.5 19.80
41 -68.748 3.16 19.44
42 -233.100 1.40 1.83481 42.7 17.24
43 25.735 0.15 16.42
44 22.443 3.26 1.71736 29.5 16.44
45 33.598 1.58 15.65
46 74.283 1.50 1.88300 40.8 15.47
47 56.958 40.00 15.17
48 162.447 5.52 1.43875 94.9 28.14
49 -33.582 1.20 1.83481 42.7 28.44
50 1043.055 0.42 29.92
51 115.690 1.20 1.83481 42.7 30.81
52 30.623 6.99 1.58144 40.8 31.79
53 -159.005 0.68 32.61
54 42.303 7.71 1.51633 64.1 36.24
55 -95.970 41.88 36.34
Image plane ∞

Aspheric data No. 29
K = 0.00000e + 000 A 4 = 9.90283e-007 A 6 = 1.41270e-010
A 8 = -2.93394e-014 A10 = 2.73055e-017 A12 = 5.80307e-022

Various data Zoom ratio 20.00

Focal length 50.00 200.00 1000.00
F number 4.70 4.70 7.20
Angle of view 17.28 4.45 0.89
Image height 15.55 15.55 15.55
Total lens length 462.14 462.14 462.14
BF 41.88 41.88 41.88

d14 3.00 78.13 129.00
d25 140.20 56.46 0.61
d31 21.64 12.81 8.79
d37 3.23 20.67 29.67

Entrance pupil position 200.48 699.43 3817.64
Exit pupil position -300.86 -300.86 -300.86
Front principal point position 243.19 782.73 1899.98
Rear principal point position -8.12 -158.12 -958.12

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 258.19 103.41 3.33 -72.20
2 15 -30.02 31.27 9.61 -11.38
3 26 80.07 17.58 5.12 -7.12
4 32 94.80 17.29 1.27 -10.66
5 38 547.52 82.65 386.49 1013.28

Single lens Data lens Start surface Focal length
1 1 420.10
2 3 332.20
3 5 -382.91
4 7 799.69
5 9 417.78
6 10 -725.96
7 12 358.70
8 13 -241.62
9 15 -56.49
10 17 -106.74
11 19 45.23
12 20 -69.10
13 22 302.16
14 24 -74.47
15 26 94.11
16 28 -157.48
17 30 119.28
18 32 120.41
19 34 -123.44
20 36 95.66
21 39 -27.50
22 40 28.30
23 42 -27.54
24 44 83.27
25 46 -286.63
26 48 63.82
27 49 -38.74
28 51 -49.93
29 52 44.51
30 54 57.75

Focus movement amount δ1P (13th lens group) -17.947
δ1S (12th lens group) 6.333

  FIG. 21 is a schematic diagram of an imaging apparatus using the zoom lens according to any one of Embodiments 1 to 6 as a photographing optical system.

  In FIG. 21, reference numeral 101 denotes the zoom lens of any one of Embodiments 1 to 6. Reference numeral 201 denotes a camera. The zoom lens 101 can be attached to and detached from the camera 201. Reference numeral 301 denotes an imaging apparatus configured by mounting the zoom lens 101 on the camera 201. The zoom lens 101 includes a first group F, a zoom unit LZ (magnification variable optical system), and a relay lens group R (imaging lens group). The first group F includes a focusing lens group. The zoom unit LZ includes a variator group that moves on the optical axis during zooming, and a compensator group that moves on the optical axis in order to correct image plane variation accompanying zooming. It is also possible to include a lens unit (extender) that does not move in the direction of the optical axis of the relay lens group R but that can be inserted and removed from the optical path for displacing the focal length of the entire zoom lens system. SP is an aperture stop. Reference numerals 102 to 104 denote driving mechanisms such as helicoids and cams for driving the lens group included in the first group F, the zooming group LZ, or the relay lens group R in the optical axis direction. Here, 105 to 108 are motors (drive means) for electrically driving the drive mechanisms 102 to 104 and the aperture stop SP.

  Reference numerals 109 to 112 denote an encoder, a potentiometer, or a photosensor for detecting the position on the optical axis of the lens group included in the first group F, the variable power group LZ, and the relay lens group R, the aperture diameter of the aperture stop SP, and the like. And so on. In the camera 201, 202 is a glass block corresponding to an optical filter or a color separation optical system, and 203 is a solid-state imaging device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor that receives a subject image formed by the zoom lens 101. . Reference numerals 204 and 113 denote CPUs that control various types of driving of the camera 201 and the zoom lens 101.

  As described above, an imaging apparatus having high optical performance is realized by applying the zoom lens of the present invention to a television camera or the like. However, the configuration of the zoom lens and the camera according to the present invention is not limited to the form shown in FIG. 21, and various modifications and changes can be made within the scope of the gist.

U1 1st lens group U11 11th lens group U12 12th lens group U13 13th lens group U14 14th lens group U2 2nd lens group U3 3rd lens group U4 4th lens group U5 5th lens group SP Aperture stop

Claims (19)

In order from the object side to the image side, a first lens group having a positive refractive power that does not move for zooming, a second lens group having a negative refractive power that moves during zooming, and one or more lens groups that move during zooming; Including an aperture stop and an imaging lens group,
The first lens group includes three or more sub lens groups including an eleventh lens group having a positive refractive power closest to the object side and a first k lens group having a negative refractive power closest to the image side. At least two of the three or more sub-lens groups are moved during
A zoom lens characterized by that. Of the sub-lens groups constituting the first lens group, the driving amount of the sub-lens group having the maximum driving amount from focusing on infinity during focus adjustment is δ1P, and then the sub-lens group having the largest driving amount is When the driving amount is δ1S,
0.03 <| δ1S / δ1P | <1.00
The zoom lens according to claim 1, wherein the following conditional expression is satisfied. Of the sub-lens groups constituting the first lens group, the focal length of the sub-lens group having the maximum drive amount from the time of focusing on infinity at the time of focus adjustment is f1P, and then the sub-lens group having the large drive amount. When the focal length is f1S,
0.15 <| f1S / f1P | <5.50
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.   The first lens group includes, in order from the object side to the image side, an eleventh lens group having a positive refractive index, a twelfth lens group having a positive refractive power, and a thirteenth lens group having a negative refractive index. The zoom lens according to claim 2 or 3.   Of the sub-lens groups constituting the first lens group, the sub-lens group having the largest drive amount from focusing on infinity during focus adjustment is the twelfth lens group, and the sub-lens having the next largest drive amount. The zoom lens according to claim 4, wherein the group is a thirteenth lens group.   Of the sub-lens groups constituting the first lens group, the sub-lens group having the largest drive amount from focusing on infinity during focus adjustment is the twelfth lens group, and the sub-lens having the next largest drive amount. The zoom lens according to claim 4, wherein the group is an eleventh lens group.   Of the sub-lens groups constituting the first lens group, the sub-lens group having the maximum drive amount from focusing on infinity during focus adjustment is the thirteenth lens group, and the sub-lens having the next largest drive amount. The zoom lens according to claim 4, wherein the group is an eleventh lens group.   The first lens group includes, in order from the object side to the image side, an eleventh lens group having a positive refractive index, a twelfth lens group having a negative refractive power, and a thirteenth lens group having a negative refractive index. The zoom lens according to claim 2 or 3.   Of the sub-lens groups constituting the first lens group, the sub-lens group having the maximum drive amount from focusing on infinity during focus adjustment is the thirteenth lens group, and the sub-lens having the next largest drive amount. The zoom lens according to claim 8, wherein the group is an eleventh lens group.   The first lens group includes, in order from the object side to the image side, an eleventh lens group having a positive refractive index, a twelfth lens group having a negative refractive power, a thirteenth lens group having a positive refractive power, and a negative refractive index. 4. The zoom lens according to claim 2, comprising a 14th lens group.   Of the sub-lens groups constituting the first lens group, the sub-lens group having the maximum drive amount from focusing on infinity during focus adjustment is the thirteenth lens group, and the sub-lens having the next largest drive amount. The zoom lens according to claim 10, wherein the group is a twelfth lens group.   The first lens group includes, in order from the object side, an eleventh lens group having a positive refractive index, a twelfth lens group having a positive refractive power, a thirteenth lens group having a positive refractive power, and a fourteenth lens having a negative refractive index. The zoom lens according to claim 2, comprising a group.   Of the sub-lens groups constituting the first lens group, the sub-lens group having the maximum drive amount from focusing on infinity during focus adjustment is the thirteenth lens group, and the sub-lens having the next largest drive amount. The zoom lens according to claim 12, wherein the group is a twelfth lens group. The distance from the center of the lens surface closest to the image side to the image side principal point position of the first lens group is Ok, and the thickness in the optical axis direction of the first lens group in the longest state from infinity to close is D1. When
0.3 <| Ok / D1 | <1.5
The zoom lens according to claim 1, wherein the following condition is satisfied. When the focal length at the time of focusing on infinity of the first lens group is f1, and the focal length of the eleventh lens group is f11,
0.5 <f11 / f1 <5.0
The zoom lens according to claim 1, wherein the following condition is satisfied. When the focal length at the time of focusing on infinity of the first lens group is f1, and the focal length at the telephoto end of the zoom lens is ft,
1.8 <ft / f1 <5.5
The zoom lens according to claim 1, wherein the following condition is satisfied. The first lens group includes a sub lens group having a positive refractive power,
When the average Abbe number of a material forming a lens having a positive refractive index included in the positive lens sub-lens group is ν1p and the average Abbe number of a material forming a lens having a negative refractive power is ν1n. ,
30 <ν1p−ν1n <85
The zoom lens according to claim 1, wherein the following condition is satisfied. A zoom lens according to any one of claims 1 to 17,
An image pickup apparatus comprising: an image pickup device that photoelectrically converts an image formed by the zoom lens. When the focal length at the telephoto end of the zoom lens is ft and the diagonal length of the effective screen of the image sensor is IS,
8.0 <ft / IS <50.0
The image pickup apparatus according to claim 18, wherein the following conditional expression is satisfied.

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