JP2017122861A - Lens system, interchangeable lens unit, and camera system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens system capable of correcting generation of various aberrations by optical elements present between a surface of the lens system closest to an image and an image plane.SOLUTION: The lens system has a plurality of lens groups each constituted by at least one lens element, and the system includes: a focus lens group that moves along an optical axis with respect to an image plane upon focusing from an infinity focusing state to a proximity object focus state; and an aberration correction lens group that has at least one lens element and moves along the optical axis with respect to the image plane. The aberration correction lens group is fixed with respect to the focus lens group and/or the image plane upon focusing. The lens system satisfies the condition of 0.1<|f/f|<9.5, where frepresents a focal distance of the aberration correction lens group; and frepresents a focal distance of the focus lens group.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a lens system, an interchangeable lens apparatus, and a camera system.

  There is an extremely high demand for high performance of cameras having an image pickup device that performs photoelectric conversion, such as an interchangeable lens device and a camera system, and various lens systems used for such cameras have been proposed. Such a camera has a parallel plate such as a low-pass filter and a cover glass of an image pickup element from the most image plane side to the image plane of the lens system, and the optical path length of these parallel plates varies from camera to camera. The optical performance of the optical image generated changes when the camera body to which the interchangeable lens device is attached changes.

  Patent Documents 1 and 2 disclose a system and a lens that correct performance fluctuation due to a change in the optical path length of a parallel plate.

Japanese Patent Laid-Open No. 2000-066286 JP 2010-020188

  The present disclosure provides a lens system capable of correcting the occurrence of various aberrations by an optical element between the most image side surface and the image plane of the lens system. The present disclosure also provides an interchangeable lens device including the lens system and a camera system including the interchangeable lens device.

The lens system according to the present disclosure is a lens system including a plurality of lens groups each including at least one lens element, and is focused on an image plane during focusing from an infinite focus state to a close object focus state. A focus lens group that moves along the optical axis, and an aberration correction lens group that has at least one lens element and moves along the optical axis with respect to the image plane. The lens is fixed with respect to the focus lens group and / or the image plane, and the following condition (1):
0.1 <| f _adj / f _focus | <9.5 (1)
(here,
f _adj : focal length of the aberration correction lens group f _focus : focal length of the focus lens group. )
It is characterized by satisfying.

The interchangeable lens device according to the present disclosure is a lens system including a plurality of lens groups each including at least one lens element, and has an image plane during focusing from an infinite focus state to a close object focus state. A focus lens group that moves along the optical axis, and an aberration correction lens group that has at least one lens element and moves along the optical axis with respect to the image plane. The lens is fixed with respect to the focus lens group or / and the image plane during focusing, and the following condition (1):
0.1 <| f _adj / f _focus | <9.5 (1)
And a lens mount unit that can be connected to a camera body having an image pickup device, obtain a signal from the camera body, and move the aberration correction lens group in accordance with the signal.

In addition, the camera system according to the present disclosure is a lens system including a plurality of lens groups each including at least one lens element, and is applied to an image plane during focusing from an infinite focus state to a close object focus state. A focus lens group that moves along the optical axis, and an aberration correction lens group that has at least one lens element and moves along the optical axis with respect to the image plane. It is fixed with respect to the focus lens group and / or the image plane during focusing, and the following condition (1):
0.1 <| f _adj / f _focus | <9.5 (1)
An interchangeable lens device having a lens system and a lens mount unit satisfying the above, and a camera body that has an image sensor and is detachably connected to the interchangeable lens device via the camera mount unit. It moves according to the signal from the camera body.

  The lens system according to the present disclosure can correct the occurrence of various aberrations, particularly the occurrence of spherical aberration, accompanying the change in the optical path length of the parallel plate between the most image side surface and the image plane of the lens system.

Lens arrangement diagram showing an infinite focus state and a close object focus state of the lens system according to the initial state of Embodiment 1 (Numerical Example 1) Longitudinal aberration diagrams of the lens system according to the initial state of Numerical Example 1 in the infinite focus state and the close object focus state Longitudinal aberration diagrams of the lens system according to the variation state of Numerical Example 1 in the infinite focus state and the close object focus state Longitudinal aberration diagram of the lens system in the correction state of Numerical Example 1 in the infinite focus state and the close object focus state Lens arrangement diagram showing an infinite focus state and a close object focus state of the lens system according to the initial state of Embodiment 2 (Numerical Example 2) Longitudinal aberration diagram of the lens system according to the initial state of Numerical Example 2 in the infinitely focused state and the close object focused state Longitudinal aberration diagrams of the lens system according to the variation state of Numerical Example 2 in the infinite focus state and the close object focus state Longitudinal aberration diagrams of the lens system in the correction state of Numerical Example 2 in the infinite focus state and the close object focus state Lens arrangement diagram showing an infinitely focused state of the zoom lens system according to the initial state of Embodiment 3 (Numerical Example 3) Longitudinal aberration diagram of the zoom lens system in the infinite focus state in the initial state of Numerical Example 3 Longitudinal aberration diagram of the zoom lens system in the close-up object in-focus state according to the initial state of Numerical Example 3 Longitudinal aberration diagram of the zoom lens system in the infinite focus state according to the variation state of Numerical Example 3 Longitudinal aberration diagram of the zoom lens system in the close focus state in the zoom lens system according to Numerical Example 3 Longitudinal aberration diagram of the zoom lens system in the infinite focus state according to the correction state of Numerical Example 3 Longitudinal aberration diagram of close-up object focusing state of zoom lens system according to correction state of Numerical Example 3 Lens arrangement diagram showing an infinitely focused state of the zoom lens system according to the initial state of Embodiment 4 (Numerical Example 4) Longitudinal aberration diagram of the zoom lens system according to the initial state of Numerical Example 4 in a focused state at infinity Longitudinal aberration diagram of close-up object focusing state of zoom lens system according to initial state of Numerical Example 4 Longitudinal aberration diagram of the zoom lens system in the infinite focus state according to the variation state of Numerical Example 4 Longitudinal aberration diagram of the zoom lens system in the close focus state in the zoom lens system according to Numerical Example 4 Longitudinal aberration diagram of the zoom lens system in the infinite focus state according to the correction state of Numerical Example 4 Longitudinal aberration diagram of the zoom lens system in the close-up object focusing state according to the correction state of Numerical Example 4 Schematic configuration diagram of a digital camera system according to Embodiment 5

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

  In addition, the inventors provide the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims. Absent.

  1, 5, 9, and 16 are lens arrangement diagrams of lens systems according to Embodiments 1 to 4, respectively. In each figure, the one-sided arrow below the lens group symbol indicates the focus lens group, and the direction of the arrow indicates the moving direction of the focus lens group from the infinite focus state to the close object focus state. ing. In each figure, the portion with a double-headed arrow is an aberration correction lens group. In each figure, a symbol (+) and a symbol (−) attached to a symbol of each lens group correspond to a power symbol of each lens group. In each figure, the straight line described on the rightmost side represents the position of the image plane S, and the rectangle on the left side of the image plane S represents the parallel plate P.

  2, 6, 10, 11, 17, and 18 are longitudinal aberration diagrams in the initial state of the lens systems according to Embodiments 1 to 4, respectively. 3, 7, 12, 13, 19, and 20 are longitudinal aberration diagrams in the variation state of the lens systems according to Embodiments 1 to 4, respectively. Further, FIGS. 4, 8, 14, 15, 21, and 22 are longitudinal aberration diagrams in the correction state of the lens systems according to Embodiments 1 to 4, respectively. Here, the initial state is a state before the thickness of the parallel plate P is changed, the fluctuation state is a state after the thickness of the parallel plate P is changed, and the correction state is a state where the thickness of the parallel plate P is changed. A state where the aberration correction lens group is moved.

  9 and 16, (a) shows the lens configuration at the wide-angle end, (b) shows the lens configuration at the intermediate position, and (c) shows the telephoto end lens configuration. Both are in focus at infinity. The intermediate position indicates an intermediate focal length state. (A) The wide-angle end in the figure indicates the shortest focal length state. (B) The intermediate position in the figure indicates the intermediate focal length state. The focal length fm in the intermediate focal length state is defined by the following formula [Equation 1].

（ｃ）図の望遠端とは最長焦点距離状態を指す。最長焦点距離状態における焦点距離はｆＴである。また各レンズ配置図において、（ａ）図と（ｃ）図との間に設けられた折れ線の矢印は、上から順に、広角端、中間位置、望遠端の各状態におけるレンズ群の位置を結んで得られる直線である。広角端と中間位置との間、中間位置と望遠端との間は、単純に直線で接続されているだけであり、実際の各レンズ群の動きとは異なる。
（実施の形態１）
図１は、実施の形態１に係るレンズ配置図を示す。図１に示すように、実施の形態１に係るレンズ系は、物体側から像側へと順に、両凸形状の第１レンズ素子Ｌ１と、両凹形状の第２レンズ素子Ｌ２と、物体側に凸面を向けた正メニスカス形状の第３レンズ素子Ｌ３と、像面側に凸面を向けた正メニスカス形状の第４レンズ素子Ｌ４と、両凹形状の第５レンズ素子Ｌ５と、物体側に凸面を向けた正メニスカス形状の第６レンズ素子Ｌ６と、開口絞りＡと、両凹形状の第７レンズ素子Ｌ７と、両凹形状の第８レンズ素子Ｌ８と、両凸形状の第９レンズ素子Ｌ９と、両凸形状の第１０レンズ素子Ｌ１０と、物体側に凸面を向けた負メニスカス形状の第１１レンズ素子Ｌ１１とからなる。なお、第１レンズ素子Ｌ１と、第２レンズ素子Ｌ２と、第３レンズ素子Ｌ３とが接合されている。また、第４レンズ素子Ｌ４と、第５レンズ素子Ｌ５とが接合されている。また、第８レンズ素子Ｌ８と、第９レンズ素子Ｌ９とが接合されている。また、第７レンズ素子Ｌ７は、その物体側が非球面である。また、第１０レンズ素子の両面は非球面である。また、第１１レンズ素子Ｌ１１は、その物体側が非球面である。

(C) The telephoto end in the figure indicates the longest focal length state. The focal length in the longest focal length state is fT. In each lens arrangement diagram, the broken line arrows provided between FIGS. (A) and (c) connect the positions of the lens groups in the states of the wide-angle end, the intermediate position, and the telephoto end in order from the top. Is a straight line obtained by The wide-angle end and the intermediate position, and the intermediate position and the telephoto end are simply connected by a straight line, which is different from the actual movement of each lens group.
(Embodiment 1)
FIG. 1 is a lens arrangement diagram according to the first embodiment. As shown in FIG. 1, the lens system according to Embodiment 1 includes, in order from the object side to the image side, a biconvex first lens element L1, a biconcave second lens element L2, and an object side. A positive meniscus third lens element L3 with a convex surface facing the surface, a positive meniscus fourth lens element L4 with a convex surface facing the image surface side, a biconcave fifth lens element L5, and a convex surface facing the object side Positive meniscus sixth lens element L6 facing the aperture, aperture stop A, biconcave seventh lens element L7, biconcave eighth lens element L8, and biconvex ninth lens element L9 And a tenth lens element L10 having a biconvex shape and an eleventh lens element L11 having a negative meniscus shape having a convex surface directed toward the object side. The first lens element L1, the second lens element L2, and the third lens element L3 are cemented. In addition, the fourth lens element L4 and the fifth lens element L5 are cemented. Further, the eighth lens element L8 and the ninth lens element L9 are cemented. The seventh lens element L7 has an aspheric object side. Further, both surfaces of the tenth lens element are aspherical surfaces. The eleventh lens element L11 is aspheric on the object side.

  In the lens system according to Embodiment 1, the focus lens group that moves along the optical axis at the time of focusing from the infinite focus state to the close object focus state includes the seventh lens element L7 and the eighth lens element L8. The ninth lens element L9 and the tenth lens element L10. These lens elements integrally move to the object side along the optical axis. At this time, since the aberration correction lens group does not move, it is fixed with respect to the image plane.

The aberration correction lens group that moves during aberration correction is the sixth lens element L6. As the aberration correction lens group, the sixth lens element L6 moves along the optical axis and corrects according to the thickness of the parallel plate P. The first embodiment shows an example in which the thickness of the parallel plate P is changed from 4 mm to 2 mm in the variation state from the initial state, and the sixth lens element L6 moves to the 2 mm image plane side in the correction state. Aberration correction is performed with.
(Embodiment 2)
FIG. 5 shows a lens layout according to the second embodiment. As shown in FIG. 5, the lens system according to Embodiment 2 includes, in order from the object side to the image side, a negative meniscus first lens element L1 with a convex surface facing the object side, and a biconvex second lens element. A lens element L2, a positive meniscus third lens element L3 with a convex surface facing the image side, a positive meniscus fourth lens element L4 with a convex surface facing the object side, and a negative with a convex surface facing the object side A fifth meniscus lens element L5, a positive meniscus sixth lens element L6 having a convex surface facing the image surface side, a biconcave seventh lens element L7, and a biconvex eighth lens element L8; , A biconvex ninth lens element L9, and a negative meniscus tenth lens element L10 with the convex surface facing the image surface side. The fourth lens element L4 and the fifth lens element L5 are cemented. Further, the seventh lens element L7 and the eighth lens element L8 are cemented. The ninth lens element L9 and the tenth lens element L10 are cemented. The third lens element L3 is aspheric on the object side. The tenth lens element L10 has an aspheric surface on the image surface side. An aperture stop A is disposed on the object side of the sixth lens element L6.

  In the lens system according to Embodiment 2, the focus lens group that moves along the optical axis at the time of focusing from the infinite focus state to the close object focus state includes the first lens element L1 to the tenth lens element L10. The entire system up to. These lens elements integrally move to the object side along the optical axis. An aberration correction lens group, which will be described later, moves together with the first lens element to the tenth lens element, which is the focus lens group, during focusing, and is thus fixed with respect to the focus lens group.

The aberration correction lens group that moves during aberration correction is the sixth lens element L6. As the aberration correction lens group, the sixth lens element L6 moves along the optical axis and corrects according to the thickness of the parallel plate P. In the second embodiment, an example is shown in which the thickness of the parallel plate P changes from 4.2 mm to 2 mm in the variation state from the initial state, and the sixth lens element L6 moves 0.5 mm toward the object side in the correction state. Thus, aberration correction is performed.
(Embodiment 3)
FIG. 9 is a lens arrangement diagram according to the third embodiment. As shown in FIG. 9, the first lens group G1 includes, in order from the object side to the image side, a positive meniscus first lens element L1 having a convex surface facing the object side, and a negative meniscus having a convex surface facing the object side. A second lens element L2 having a shape, a third lens element L3 having a positive meniscus shape having a convex surface facing the object side, a fourth lens element L4 having a biconcave shape, and a first lens having a negative meniscus shape having a convex surface facing the object side. 5 lens element L5, biconvex sixth lens element L6, negative meniscus seventh lens element L7 having a convex surface facing the object side, biconvex eighth lens element L8, and convex surface facing the object side And a tenth lens element L10 having a positive meniscus shape with a convex surface facing the object side. The second lens element L2 and the third lens element L3 are cemented. Further, the fifth lens element L5 and the sixth lens element L6 are cemented. The sixth lens element L6 has an aspheric image surface side.

  The second lens group G2 includes, in order from the object side to the image side, a negative meniscus eleventh lens element L11 having a convex surface directed toward the object side, a biconcave twelfth lens element L12, and a biconvex second lens element L12. 13 lens elements L13 and a negative meniscus fourteenth lens element L14 having a convex surface facing the image surface side. Among these, the eleventh lens element L11 is aspheric on the object side.

  The third lens group G3 includes, in order from the object side to the image side, a biconcave fifteenth lens element L15 and a positive meniscus sixteenth lens element L16 with a convex surface facing the object side. The fifteenth lens element L15 and the sixteenth lens element L16 are cemented.

  The fourth lens group G4 includes, in order from the object side to the image side, a biconvex seventeenth lens element L17, a negative meniscus eighteenth lens element L18 with a convex surface facing the image surface, and a biconvex shape. A nineteenth lens element L19, a negative meniscus twentieth lens element L20 having a convex surface facing the image side, a positive meniscus twentieth lens element L21 having a convex surface facing the object side, and a biconcave twenty-second lens element L21. A lens element L22, a biconvex 23rd lens element L23, a biconcave 24th lens element L24, a biconvex 25th lens element L25, a biconvex 26th lens element L26, and an object It consists of a positive meniscus twenty-seventh lens element L27 with a convex surface facing the side, and a biconcave twenty-eighth lens element L28. The seventeenth lens element L17 and the eighteenth lens element L18 are cemented. The nineteenth lens element L19 and the twentieth lens element L20 are cemented. The 22nd lens element L22 and the 23rd lens element L23 are cemented. In the fourth lens group G4, an aperture stop A is disposed on the object side of the seventeenth lens element L17.

  In the lens system according to Embodiment 3, the second lens element L2, the third lens element L3, and the fourth lens element L4 are in focus when focusing from the infinite focus state to the close object focus state. The ninth lens element L9 and the tenth lens element L10 integrally move along the optical axis toward the object side along the optical axis. At this time, since the aberration correction lens group does not move, it is fixed with respect to the image plane.

The aberration correction lens group that moves during aberration correction is the twenty-fourth lens element L24. The twenty-fourth lens element L24 as the aberration correction lens group moves along the optical axis and corrects according to the thickness of the parallel plate P. The third embodiment shows an example in which the thickness of the parallel plate P changes from 5 mm to 1 mm in the variation state from the initial state, and in the correction state, the 24th lens element L24 moves to the 0.04 mm image plane side. Aberration correction is performed.
(Embodiment 4)
FIG. 16 is a lens arrangement diagram according to the fourth embodiment. As shown in FIG. 16, the first lens group G1 includes, in order from the object side to the image side, a negative meniscus first lens element L1 having a convex surface facing the object side, and a negative meniscus having a convex surface facing the object side. A second lens element L2 having a shape, a third lens element L3 having a positive meniscus shape having a convex surface facing the object side, a fourth lens element L4 having a negative meniscus shape having a convex surface facing the image surface side, and a convex surface facing the object side Negative meniscus fifth lens element L5 facing the lens, biconvex sixth lens element L6, negative meniscus seventh lens element L7 with the convex surface facing the object side, and biconvex eighth lens It comprises an element L8, a biconvex ninth lens element L9, and a positive meniscus tenth lens element L10 with the convex surface facing the object side. The second lens element L2 and the third lens element L3 are cemented. The fifth lens element L5 and the sixth lens element L6 are cemented. The seventh lens element L7 and the eighth lens element L8 are cemented. The sixth lens element L6 has an aspheric image surface side.

  The second lens group G2 includes, in order from the object side to the image side, a negative meniscus eleventh lens element L11 having a convex surface directed toward the object side, a biconcave twelfth lens element L12, and a biconvex second lens element L12. 13 lens elements L13 and a negative meniscus fourteenth lens element L14 having a convex surface facing the image surface side. The eleventh lens element L11 has an aspheric object side.

  The third lens group G3 includes, in order from the object side to the image side, a biconcave fifteenth lens element L15 and a positive meniscus sixteenth lens element L16 with a convex surface facing the object side. The fifteenth lens element L15 and the sixteenth lens element L16 are cemented.

  The fourth lens group G4 includes, in order from the object side to the image side, a biconvex seventeenth lens element L17, a negative meniscus eighteenth lens element L18 with a convex surface facing the image surface, and a biconvex shape. A nineteenth lens element L19, a negative meniscus twentieth lens element L20 having a convex surface facing the image side, a positive meniscus twenty-first lens element L21 having a convex surface facing the object side, and a biconcave twenty-second lens element L21. A lens element L22, a biconvex 23rd lens element L23, a biconcave 24th lens element L24, a biconvex 25th lens element L25, a biconvex 26th lens element L26, and an object It consists of a positive meniscus twenty-seventh lens element L27 with a convex surface facing the side, and a biconcave twenty-eighth lens element L28. The seventeenth lens element L17 and the eighteenth lens element L18 are cemented. The nineteenth lens element L19 and the twentieth lens element L20 are cemented. The 22nd lens element L22 and the 23rd lens element L23 are cemented. In the fourth lens group G4, an aperture stop A is disposed on the object side of the seventeenth lens element L17.

  In the lens system according to Embodiment 4, the focus lens group that moves along the optical axis during focusing from the infinitely focused state to the close object focused state includes the second lens element L2 and the third lens element L3. And the fourth lens element L4. These lens elements integrally move toward the object side along the optical axis. At this time, since the aberration correction lens group does not move, it is fixed with respect to the image plane.

  The aberration correction lens group that moves during aberration correction is the 25th lens element L25. The twenty-fifth lens element L25 moves along the optical axis as an aberration correction lens group and corrects according to the thickness of the parallel plate P. In the fourth embodiment, an example in which the thickness of the parallel plate P is changed from 5 mm to 2 mm in the changed state from the initial state is shown, and in the corrected state, the 25th lens element L25 is moved to the object side by 0.03 mm so that the aberration is increased. Make corrections.

  In the lens systems according to Embodiments 1 to 4, the lens system includes a plurality of lens groups each including at least one lens element, and is used for focusing from an infinitely focused state to a close object focused state. A focus lens group that moves along the optical axis with respect to the image plane; and an aberration correction lens group that has at least one lens element and moves along the optical axis with respect to the image plane, the aberration correction Since the lens group is fixed with respect to the focus lens group and / or the image plane during focusing, the occurrence of various aberrations can be suppressed.

  In addition, it is advantageous that the aberration correction lens group in the lens systems according to Embodiments 1 to 4 includes a single lens element. By setting the number of aberration correction lens groups to one, aberration correction can be performed with a simple mechanism, and compactness can be easily achieved.

  In addition, it is advantageous that the lens systems according to Embodiments 1 to 4 further include an aperture stop, and the aberration correction lens group is disposed on the image plane side with respect to the aperture stop. By arranging an aberration correction lens group on the image plane side of the aperture stop, aberration correction is performed for changes in the optical path length of the parallel plate P of the low-pass filter between the most image side surface of the lens system and the image plane due to focusing and zooming. A change in the amount of movement of the optical axis of the lens group can be reduced, and aberration correction can be performed with a simple mechanism.

  In the lens systems according to Embodiments 1 to 4, since the focusing lens group is composed of three or less lens elements, high-speed and silent focusing can be performed.

  As described above, Embodiments 1 to 4 have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed.

  Hereinafter, conditions that can be satisfied by a lens system such as the lens systems according to Embodiments 1 to 4 will be described. A plurality of possible conditions are defined for the lens system according to each embodiment, but a lens system configuration that satisfies all of the plurality of conditions is most effective. However, by satisfying individual conditions, it is also possible to obtain lens systems that exhibit corresponding effects.

  For example, as in the lens systems according to Embodiments 1 to 4, the lens system includes a plurality of lens groups each including at least one lens element, and focusing from an infinite focus state to a close object focus state A focus lens group that moves along the optical axis with respect to the image plane, and an aberration correction lens group that has at least one lens element and moves along the optical axis with respect to the image plane, The aberration correction lens group is fixed to the focus lens group and / or the image surface during focusing (hereinafter, this lens configuration is referred to as a basic configuration of the embodiment) under the following conditions (1 ) Is satisfied.

0.1 <| f _adj / f _focus | <9.5 (1)
here,
f _adj : focal length of the aberration correction lens group f _focus : focal length of the focus lens group having the smallest absolute value of the focal length.

  Condition (1) defines the ratio between the focal length of the aberration correction group lens group and the focal length of the focus lens group. Satisfying the condition (1) facilitates spherical aberration correction by the aberration correction lens group. If the lower limit of condition (1) is not reached, the power of the aberration correction lens group becomes too strong with respect to the power of the focus lens group, and it becomes difficult to correct spherical aberration due to movement of the aberration correction lens group in the optical axis direction. On the other hand, if the upper limit of the condition (1) is exceeded, the power of the aberration correction lens group becomes too weak with respect to the power of the focus lens group, and it becomes difficult to correct the field curvature fluctuation accompanying the focusing.

  By satisfying the following condition (1) ′, the above effect can be further achieved.

0.12 <| f _adj / f _focus | <1.0 (1) ′
For example, as in the lens systems according to Embodiments 1 to 4, it is beneficial that the lens system having the basic configuration satisfies the following condition (2).

0.05 <| f _adj / f | <2 (2)
here,
f: The focal length of the entire lens system when focused at infinity.

Condition (2) is a condition that defines the ratio between the focal length of the aberration correction group lens group and the focal length of the entire lens system. When the condition (2) is satisfied, spherical aberration correction by the aberration correction lens group becomes easy. If the lower limit of condition (2) is not reached, the power of the aberration correction lens group becomes too strong relative to the power of the entire lens system, and it becomes difficult to correct spherical aberration due to movement of the aberration correction lens group in the optical axis direction. On the contrary, if the upper limit of the condition (2) is exceeded, the power of the aberration correction lens group becomes too weak with respect to the power of the entire lens system, and it becomes difficult to correct coma.
By satisfying the following condition (2) ′, the above effect can be further achieved.

0.07 <| f _adj /f|<1.6 (2) ′
For example, as in the lens systems according to Embodiments 1 to 4, it is beneficial that the lens system having the basic configuration satisfies the following condition (3).

1.5 <| f _adj / H | <30 (3)
here,
H: Image height of the lens system.

  Condition (3) defines the ratio between the focal length of the aberration correction group lens group and the image height of the lens system. When the condition (3) is satisfied, the power of the lens group constituting the aberration correction group lens group can be set appropriately, spherical aberration correction by the aberration correction lens group becomes easy, and at the same time, the lens system can be reduced in size. If the lower limit of the condition (3) is not reached, the power of the aberration correction group lens group becomes too strong, and it becomes difficult to correct spherical aberration by moving the aberration correction lens group in the optical axis direction. On the contrary, if the upper limit of the condition (3) is exceeded, the movement amount in the optical axis direction of the aberration correction group lens group becomes too long, and it becomes difficult to achieve compactness. Moreover, the diameter of each lens becomes too large, and it becomes difficult to suppress the occurrence of spherical aberration.

  By satisfying the following condition (3) ′, the above effect can be further achieved.

2.0 <| f _adj / H | <25 (3) ′
For example, as in the lens systems according to Embodiments 1 to 4, it is beneficial that the lens system having the basic configuration satisfies the following condition (4).

0.05 <| f _adj / L | <5 (4)
here,
L: Total optical length of the lens system Condition (4) is a condition that defines the ratio between the focal length of the aberration correction group lens group and the total optical length of the lens system. When the condition (4) is satisfied, the power of the lens group constituting the aberration correction group lens group can be set appropriately, the spherical aberration correction by the aberration correction lens group becomes easy, and at the same time, the lens system can be reduced in size. If the lower limit of condition (4) is not reached, the total optical length of the lens system becomes too long, making it difficult to achieve compactness. Moreover, the diameter of each lens becomes too large, and it becomes difficult to suppress the occurrence of spherical aberration.
On the other hand, if the upper limit of condition (4) is exceeded, the power of each lens constituting the lens system becomes too strong, and it becomes difficult to suppress the occurrence of various aberrations, particularly coma.

  By satisfying the following condition (4) ′, the above effect can be further achieved.

0.06 <| f _adj / L | <4 (4) ′
For example, as in the lens systems according to Embodiments 1 to 4, it is beneficial that the lens system having the basic configuration satisfies the following condition (5).

0.2 <H × Fno. /F<1.5 (5)
here,
Fno. : F value of the lens system.

  Condition (5) is a condition that defines the relationship between the image height and F value of the lens system and the focal length of the entire lens system. When the condition (5) is satisfied, the power of each lens group constituting the lens system can be set appropriately, the spherical aberration can be easily controlled, and the lens system can be reduced in size. If the lower limit of condition (5) is not reached, the power of the lens group constituting the lens system becomes too strong, and it becomes difficult to suppress the occurrence of spherical aberration. On the contrary, if the upper limit of the condition (5) is exceeded, the optical total length of the lens system becomes too large, and it becomes difficult to achieve compactness. Moreover, the diameter of each lens becomes too large, and it becomes difficult to suppress the occurrence of spherical aberration.

  By satisfying the following condition (5) ′, the above effect can be further achieved.

0.3 <H × Fno. /F<1.0 (5) '
For example, as in the lens systems according to Embodiments 1 to 4, it is beneficial that the lens system having the basic configuration satisfies the following condition (6).

0.5 <| f _focus / f | <12 (6)
here,
f _focus : the focal length of the focus lens group having the smallest absolute value of the focal length.

  Condition (6) is a condition that defines the ratio between the focal length of the focus lens group and the focal length of the lens system. When the condition (6) is satisfied, the power of the focus lens group can be set appropriately, and the control of astigmatism fluctuations accompanying focusing becomes easy. Below the lower limit of condition (6), the power of the focus lens group becomes too strong, and it becomes difficult to suppress the occurrence of astigmatism. On the other hand, if the upper limit of condition (6) is exceeded, the focal length of the entire lens system becomes too short, and it becomes difficult to suppress the occurrence of distortion.

  By satisfying the following condition (6) ′, the above effect can be further achieved.

0.6 <| f _focus / f | <8 (6) ′
For example, as in the lens systems according to Embodiments 1 to 4, it is beneficial that the lens system having the basic configuration satisfies the following condition (7).

2 <| f _focus / H | <25 (7)
Condition (7) is a condition that defines the ratio between the focal length of the focus lens group and the image height of the lens system. When the condition (7) is satisfied, the power of the focus lens group can be set appropriately, and the control of astigmatism fluctuations accompanying focusing becomes easy. Below the lower limit of condition (7), the power of the focus lens group becomes too strong, and it becomes difficult to suppress the occurrence of astigmatism. On the other hand, if the upper limit of condition (7) is exceeded, the power of the focus lens group becomes too weak and the amount of movement of the focus lens group in the optical axis direction becomes large, making it difficult to achieve compactness.

  By satisfying the following condition (7) ', the above effect can be further achieved.

10 <| f _focus / H | <22 (7) ′
For example, as in the lens systems according to Embodiments 1 to 4, it is beneficial that the lens system having the basic configuration satisfies the following condition (8).

0.3 <| f _focus / L | <3 (8)
Condition (8) is a condition that defines the ratio of the focal length of the focus lens group to the total optical length of the lens system. When the condition (8) is satisfied, the power of the focus lens group can be set appropriately, and the control of astigmatism fluctuations accompanying focusing becomes easy. Below the lower limit of condition (8), the power of the focus lens group becomes too strong, and it becomes difficult to suppress the occurrence of astigmatism. On the other hand, if the upper limit of condition (8) is exceeded, the power of the focus lens group becomes too weak, and the amount of movement of the focus lens group in the optical axis direction becomes large, making it difficult to achieve compactness.

  By satisfying the following condition (8) ′, the above effect can be further achieved.

0.31 <| f _focus / L | <2 (8) ′
For example, as in the lens systems according to Embodiments 1 to 4, it is beneficial that the lens system having the basic configuration satisfies the following condition (9).

0.1 <L _C / L <1 (9)
here,
L _C : Distance on the optical axis from the most image side surface of the aberration correction lens group to the image surface.

  Condition (9) is a condition that defines the ratio of the distance on the optical axis from the most image side surface of the aberration correction lens group to the image surface and the total optical length of the lens system. When the condition (9) is satisfied, the thickness of the aberration correction lens group can be set appropriately, and the correction of longitudinal chromatic aberration is facilitated. If the lower limit of the condition (9) is not reached, the power of the aberration correction lens group becomes too weak, and it becomes difficult to correct spherical aberration. On the contrary, if the upper limit of the condition (9) is exceeded, the power of the aberration correction lens group becomes too strong, and it becomes difficult to suppress the occurrence of longitudinal chromatic aberration.

  By satisfying the following condition (9) ', the above effect can be further achieved.

0.12 <L _C /L<0.8 (9) ′
For example, as in the lens systems according to Embodiments 1 to 4, it is beneficial that the lens system having the basic configuration satisfies the following condition (10).

1 <L _C /BF<3.0 (10)
here,
BF: Lens system back focus.

  Condition (10) is a condition that defines the ratio of the distance on the optical axis from the most image side surface of the aberration correction lens group to the image surface and the back focus of the lens system. When the condition (10) is satisfied, the thickness of the aberration correction lens group can be set appropriately, and the correction of axial chromatic aberration is facilitated. If the lower limit of the condition (10) is not reached, the power of the aberration correction lens group becomes too weak, and it becomes difficult to correct spherical aberration. On the contrary, if the upper limit of the condition (10) is exceeded, the power of the aberration correction lens group becomes too strong, and it becomes difficult to suppress the occurrence of longitudinal chromatic aberration.

  By satisfying the following condition (10) ', the above effect can be further achieved.

1.3 <L _C /BF<2.5 (10) ′
Each lens group constituting the lens system according to Embodiments 1 to 4 includes a refractive lens element that deflects incident light by refraction (that is, a type in which deflection is performed at an interface between media having different refractive indexes). Lens element), but is not limited to this. For example, a diffractive lens element that deflects incident light by diffraction, a refractive / diffractive hybrid lens element that deflects incident light by a combination of diffractive action and refractive action, and a refractive index that deflects incident light according to the refractive index distribution in the medium Each lens group may be composed of a distributed lens element or the like. In particular, in a refractive / diffractive hybrid lens element, when a diffractive structure is formed at the interface of media having different refractive indexes, the wavelength dependence of diffraction efficiency is improved.

Each lens element constituting the lens system according to Embodiments 1 to 4 may be a hybrid lens in which a transparent resin layer made of an ultraviolet curable resin is bonded to one surface of a lens element made of glass. . In this case, since the power of the transparent resin layer is weak, the lens element made of glass and the transparent resin layer are considered as one lens element. Similarly, when a lens element close to a flat plate is arranged, the power of the lens element close to the flat plate is weak, so it is considered as zero lens elements.
(Embodiment 5)
FIG. 23 is a schematic configuration diagram of an interchangeable lens digital camera system according to the fifth embodiment.

  The interchangeable lens digital camera system 100 according to the fifth embodiment includes a camera body 101 and an interchangeable lens apparatus 201 that is detachably connected to the camera body 101.

  The camera body 101 receives an optical image formed by the lens system 202 of the interchangeable lens apparatus 201 and converts it into an electrical image signal, and a parallel plate P disposed on the subject side of the image sensor 102. A liquid crystal monitor 103 that displays an image signal converted by the image sensor 102, and a camera mount unit 104. The parallel plate P includes a cover glass that covers the low-pass filter and the image sensor 102. On the other hand, the interchangeable lens device 201 includes a lens system 202 according to any of Embodiments 1 to 4, a lens barrel 203 that holds the lens system 202, and a lens mount unit 204 that is connected to the camera mount unit 104 of the camera body. And a flange back adjustment mechanism 205. The camera mount unit 104 and the lens mount unit 204 electrically connect not only a physical connection but also a controller (not shown) in the camera body 101 and a controller (not shown) in the interchangeable lens device 201. It also functions as an interface that enables mutual signal exchange. Note that FIG. 23 illustrates a case where the lens system according to Embodiment 1 is used as the lens system 202.

  In the fifth embodiment, since the lens system 202 according to any one of the first to fourth embodiments is used, an interchangeable lens apparatus that is compact and excellent in imaging performance can be realized at low cost. Further, it is possible to reduce the size and cost of the entire camera system 100 according to the fifth embodiment.

  In the interchangeable lens digital camera system according to the fifth embodiment, the lens system according to the first to fourth embodiments is shown as the lens system 202. However, these lens systems do not use the entire focusing area. May be. That is, a range in which the optical performance is ensured may be cut out and used according to a desired focusing area.

  An interchangeable lens apparatus 201 according to Embodiment 5 includes a lens mount that can connect a lens system 202 having a basic configuration like the lens systems according to Embodiments 1 to 4 and a camera body 101 having an image sensor 102. Part 204. The interchangeable lens device 201 acquires a signal from the camera body 101, and the aberration correction lens group moves according to the signal. This signal includes information on the amount of movement of the aberration correction lens group in the optical axis direction with respect to the initial state. Thereby, the user can easily perform aberration correction by the signal from the camera body 101.

  Further, the interchangeable lens apparatus 201 according to Embodiment 5 adjusts the flange back to change the air interval from the image sensor 102 to the most image side surface of the lens system 202 by moving the lens system 202 uniformly along the optical axis. A mechanism 205 is provided. Thereby, the back focus which fluctuates by the movement of the aberration correction lens group provided in the lens system 202 in the optical axis direction can be corrected.

  In addition, the interchangeable lens device 201 according to Embodiment 5 further includes an operation unit 206. The operation unit 206 can move the aberration adjustment lens group included in the lens system 202 along the optical axis. Thereby, the user can easily perform aberration correction. The operation unit 206 and the aberration adjustment lens group may be mechanically connected, or the operation of the operation unit 206 may be converted into an electrical signal, and the aberration adjustment lens may be operated by a stepping motor. The operation unit 206 is not limited to the interchangeable lens device 201 and may be provided in the camera body 101. In this case, the camera body 101 and the interchangeable lens device 201 are electrically connected, and the interchangeable lens device 201 moves the aberration adjustment lens group along the optical axis by receiving a signal from the camera body 101.

  In addition, an imaging apparatus including the lens system according to Embodiments 1 to 4 described above and an imaging element such as a CCD or a CMOS is used as a camera for a portable information terminal such as a smartphone, a surveillance camera in a surveillance system, or a Web camera. It can also be applied to in-vehicle cameras.

  As described above, the fifth embodiment has been described as an example of the technique disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed.

  Hereinafter, numerical examples in which the lens systems according to Embodiments 1 to 4 are specifically implemented will be described. In each numerical example, the unit of length in the table is “mm”, and the unit of angle of view is “°”. In each numerical example, r is a radius of curvature, d is a surface interval, nd is a refractive index with respect to the d line, and vd is an Abbe number with respect to the d line. In each numerical example, the surface marked with * is an aspherical surface, and the aspherical shape is defined by the following equation.

１０〜１５、及び１７〜２２は、図２と図６は、各々数値実施例１、２に係るレンズ系の初期状態における無限遠合焦状態及び近接物体合焦状態の縦収差図である。図３と図７は、各々数値実施例１〜２に係るレンズ系の変動状態における無限遠合焦状態及び近接物体合焦状態の縦収差図である。図４と図８は、各々数値実施例１〜２に係るレンズ系の補正状態における無限遠合焦状態及び近接物体合焦状態の縦収差図である。図１０と図１７は、各々数値実施例３、４に係るレンズ系の初期状態における無限遠合焦状態の縦収差図である。図１１と図１８は、各々数値実施例３、４に係るレンズ系の初期状態における近接物体合焦状態の縦収差図である。図１２と図１９は、各々数値実施例３、４に係るレンズ系の変動状態における無限遠合焦状態の縦収差図である。図１３と図２０は、各々数値実施例３、４に係るレンズ系の変動状態における近接物体合焦状態の縦収差図である。図１４と図２１は、各々数値実施例３、４に係るレンズ系の補正状態における無限遠合焦状態の縦収差図である。図１５と図２２は、各々数値実施例３、４に係るレンズ系の補正状態における近接物体合焦状態の縦収差図である。

FIGS. 2 and 6 are longitudinal aberration diagrams of the lens system according to Numerical Examples 1 and 2, respectively, in an infinite focus state and a close object focus state. FIGS. 3 and 7 are longitudinal aberration diagrams in the infinite focus state and the close object focus state in the variation state of the lens systems according to Numerical Examples 1 and 2, respectively. 4 and 8 are longitudinal aberration diagrams in the infinite focus state and the close object focus state in the correction state of the lens systems according to Numerical Examples 1 and 2, respectively. 10 and 17 are longitudinal aberration diagrams in the infinitely focused state in the initial state of the lens systems according to Numerical Examples 3 and 4, respectively. FIGS. 11 and 18 are longitudinal aberration diagrams of the close-up object in-focus state in the initial state of the lens systems according to Numerical Examples 3 and 4, respectively. 12 and 19 are longitudinal aberration diagrams in the infinite focus state in the variation state of the lens systems according to Numerical Examples 3 and 4, respectively. FIGS. 13 and 20 are longitudinal aberration diagrams in the close object in-focus state in the variation state of the lens systems according to Numerical Examples 3 and 4, respectively. FIGS. 14 and 21 are longitudinal aberration diagrams in the infinite focus state in the correction state of the lens systems according to Numerical Examples 3 and 4, respectively. FIGS. 15 and 22 are longitudinal aberration diagrams in the close object in-focus state in the correction state of the lens systems according to Numerical Examples 3 and 4, respectively.

  In each longitudinal aberration diagram of FIGS. 2 to 4 and 6 to 8, (a) shows the aberration in the infinite focus state, and (b) shows each aberration in the close object focusing state.

10 to 15 and 17 to 22, (a) is a wide-angle end focused state, (b) is an intermediate position focused state, and (c) is a telephoto position focused state. Represents aberration.
Each longitudinal aberration diagram shows spherical aberration (SA (mm)), astigmatism (AST (mm)), and distortion (DIS (%)) in order from the left side. In the spherical aberration diagram, the vertical axis represents the F number (indicated by F in the figure), the solid line is the d line (d-line), the short broken line is the F line (F-line), and the long broken line is the C line (C- line). In the astigmatism diagram, the vertical axis represents the image height (indicated by H in the figure), the solid line represents the sagittal plane (indicated by s), and the broken line represents the meridional plane (indicated by m in the figure). is there. In the distortion diagram, the vertical axis represents the image height (indicated by H in the figure).
(Numerical example 1)
The lens system of Numerical Example 1 corresponds to Embodiment 1 shown in FIG. The surface data of the lens system of Numerical Example 1 is shown as data 1, the aspheric data is shown as data 2, the various data is shown as data 3, the short lens data is shown as data 4, and the lens group data is shown as data 5.
Data 1 (surface data)
Surface number rd nd vd
Surface ∞ Variable
1 86.02800 13.32720 2.00272 19.3
2 -232.42490 4.00000 1.75211 25.0
3 34.66350 15.65380 1.80420 46.5
4 216.02390 5.85120
5 -305.56660 5.97100 2.00100 29.1
6 -69.03420 2.50000 1.84666 23.8
7 61.48830 Variable
8 155.09680 3.06110 1.80420 46.5
9 239.32980 Variable
10 (Aperture) ∞ Variable
11 * -2000.00000 3.00000 1.80470 41.0
12 493.96930 7.09490
13 -38.78490 2.00000 1.75211 25.0
14 55.45670 15.83290 1.91082 35.2
15 -53.84940 0.50000
16 * 289.64490 17.80480 1.80470 41.0
17 * -73.03400 Variable
18 * 90.00000 3.00000 1.51443 63.3
19 79.19340 Variable
20 ∞ Variable 1.51680 64.2
21 ∞ 1.00000
22 ∞ BF
Image plane ∞
Data 2 (Aspherical data)
11th page
K = 0.00000E + 00, A4 = -3.17300E-06, A6 = -2.51200E-09, A8 = -1.38564E-12
A10 = -2.14975E-15
16th page
K = 0.00000E + 00, A4 = -1.01958E-06, A6 = -4.38347E-10, A8 = 2.34646E-13
A10 = -8.85515E-16
17th page
K = 0.00000E + 00, A4 = -4.40994E-07, A6 = -7.45031E-12, A8 = -4.47121E-13
A10 = -5.80073E-17
18th page
K = 0.00000E + 00, A4 = -4.08812E-08, A6 = 1.11324E-09, A8 = -2.14186E-12
A10 = 1.53884E-15
Data 3 (various data)
Infinity initial proximity initial infinity variation infinity variation proximity variation infinity correction proximity correction focal length 87.9998 84.9220 87.9998 84.9220 87.6831 84.6295
F number 1.36493 1.42781 1.36493 1.42781 1.36542 1.42817
Angle of view 14.1303 13.8228 14.1294 13.8211 14.1931 13.8793
Image height 21.6300 21.6300 21.6300 21.6300 21.6300 21.6300
Total lens length 179.9998 179.9998 179.3178 179.3178 179.3178 179.3178
BF 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000
d0 ∞ 820.0000 ∞ 820.0000 ∞ 820.0000
d7 7.0000 7.0000 7.0000 7.0000 9.0000 9.0000
d9 5.9134 5.9134 5.9134 5.9134 3.9134 3.9134
d10 13.4895 5.0000 13.4895 5.0000 13.4895 5.0000
d17 4.0000 12.4895 4.0000 12.4895 4.0000 12.4895
d19 45.0000 45.0000 46.3180 46.3180 46.3180 46.3180
d20 4.0000 4.0000 2.0000 2.0000 2.0000 2.0000
Entrance pupil position 76.5992 76.5992 76.5992 76.5992 76.4250 76.4250
Exit pupil position -221.6312 -144.1997 -221.6306 -144.1992 -221.6306 -144.1992
Front principal point position 129.6612 108.3928 129.6612 108.3928 129.4317 108.3155
Rear principal point position 92.0189 86.6199 91.3375 85.9385 91.7207 86.2929
Data 4 (single lens data)
Lens Start surface Focal length
1 1 63.9577
2 2 -39.8507
3 3 49.4393
4 5 87.9821
5 6 -38.0771
6 8 539.2310
7 11 -492.0078
8 13 -30.0714
9 14 32.2202
10 16 74.1049
11 18 -1415.5706
Data 5 (Lens group data)
Group Start surface Focal length Lens construction length Front principal point position Rear principal point position
1 1 875.43184 47.30320 -394.90656 -244.35050
2 8 539.23105 3.06110 -3.07422 -1.68273
3 11 57.36503 46.23260 31.30308 54.67336
4 18 -1415.57057 3.00000 18.21549 19.02830
(Numerical example 2)
The lens system of Numerical Example 2 corresponds to Embodiment 2 shown in FIG. Surface data of the lens system of Numerical Example 2 is shown as data 6, aspherical data is shown as data 7, various data is shown as data 8, single lens data is shown as data 9, and lens group data is shown as data 10.
Data 6 (surface data)
Surface number rd nd vd
Surface ∞ Variable
1 136.93790 5.00000 1.50257 68.8
2 46.20230 3.99020
3 79.48210 7.27440 1.75520 27.6
4 -2276.00020 15.87880
5 * -69.51010 10.00000 1.88202 37.2
6 -63.49930 0.50000
7 28.44210 9.51800 1.62041 60.3
8 123.44630 3.00000 1.75520 27.6
9 20.94970 10.00000
10 (Aperture) ∞ Variable
11 -52.83090 2.50000 1.54162 65.3
12 -42.29440 Variable
13 -28.19100 2.00000 1.75211 25.0
14 56.92780 15.20 300 2.00 100 29.1
15 -43.75240 0.50000
16 76.66110 14.43560 1.62041 60.3
17 -36.11640 2.00000 1.68400 31.3
18 * -74.03550 variable
19 ∞ Variable 1.51680 64.2
20 ∞ 1.00000
21 ∞ BF
Image plane ∞
Data 7 (Aspherical data)
5th page
K = 0.00000E + 00, A4 = -4.35098E-07, A6 = 1.13248E-09, A8 = -2.52810E-12
A10 = 2.20433E-15
18th page
K = 0.00000E + 00, A4 = 2.04569E-06, A6 = -5.81204E-10, A8 = 1.00339E-12
A10 = 2.95604E-17
Data 8 (various data)
Infinity initial proximity initial infinity variation infinity variation proximity variation infinity correction proximity correction focal length 51.2499 51.2499 51.2499 51.2499 51.3214 51.3214
F number 1.24808 1.26818 1.24808 1.26818 1.24983 1.27009
Angle of view 24.3073 24.0486 24.3067 24.0479 24.2719 24.0109
Image height 21.6300 21.6300 21.6300 21.6300 21.6300 21.6300
Total lens length 160.0000 162.8369 159.2504 162.0873 159.2504 162.0873
BF 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000
d0 ∞ 837.1631 ∞ 837.1631 ∞ 837.1631
d10 6.0000 6.0000 6.0000 6.0000 5.5000 5.5000
d12 7.0000 7.0000 7.0000 7.0000 7.5000 7.5000
d18 40.0000 42.8369 41.4504 44.2873 41.4504 44.2873
d19 4.2000 4.2000 2.0000 2.0000 2.0000 2.0000
Entrance pupil position 58.5490 58.5490 58.5490 58.5490 58.5490 58.5490
Exit pupil position -169.2799 -172.1168 -169.2799 -172.1168 -168.6910 -171.5279
Front principal point position 94.2842 94.2842 94.2842 94.2842 94.2582 94.2582
Rear principal point position 108.7650 108.7650 108.0154 108.0154 107.9447 107.9447
Data 9 (single lens data)
Lens Start surface Focal length
1 1 -141.3475
2 3 101.8302
3 5 467.7997
4 7 57.3682
5 8 -33.8367
6 11 361.4169
7 13 -24.8182
8 14 26.7337
9 16 41.6103
10 17 -105.3502
Data 10 (lens group data)
Group Start surface Focal length Lens construction length Front principal point position Rear principal point position
1 1 -774.36020 65.16140 234.51270 208.54333
2 11 361.41689 2.50000 7.50554 8.50865
3 13 43.96546 34.13860 17.67823 36.23598
(Numerical Example 3)
The lens system of Numerical Example 3 corresponds to Embodiment 3 shown in FIG. Surface data of the lens system of Numerical Example 3 is shown as data 11, aspherical data is shown as data 12, various data are shown as data 13, single lens data is shown as data 14, and zoom lens group data is shown as data 15.
Data 11 (surface data)
Surface number rd nd vd
Surface ∞ Variable
1 313.93790 8.00000 1.75520 27.6
2 500.00000 Variable
3 3392.96640 3.40000 1.68634 44.8
4 105.89870 18.15090 1.75262 30.2
5 290.83070 19.54980
6 -189.36680 3.20000 1.70617 48.2
7 7620.41690 Variable
8 800.00000 3.30000 1.71619 29.3
9 296.59350 21.71790 1.59499 50.1
10 * -158.73260 0.20000
11 387.41140 3.10000 1.75411 28.6
12 127.42220 2.40000
13 158.15290 15.33240 1.43700 95.1
14 -724.64840 Variable
15 110.08950 16.55760 1.43700 95.1
16 ∞ 0.20000
17 133.04920 9.48190 1.49700 81.6
18 507.41770 Variable
19 * 266.32680 1.50000 1.70410 48.4
20 32.89190 11.50000
21 -48.29400 1.40000 1.56226 63.8
22 170.65390 0.20000
23 74.94580 13.12910 1.75378 29.0
24 -55.97070 1.10000
25 -42.91760 1.30000 1.58723 40.4
26 -578.22210 Variable
27 -66.79670 1.50000 1.69717 49.1
28 179.08850 3.45470 1.92286 18.9
29 35750.45340 Variable
30 (Aperture) ∞ 1.80000
31 134.34700 10.71350 1.63904 56.9
32 -47.87310 1.50000 1.61359 38.2
33 -61.82290 0.50000
34 93.69640 11.43620 1.49363 69.7
35 -47.59610 1.50000 2.00069 25.5
36 -173.34260 0.20000
37 62.40810 5.21090 1.60091 61.4
38 208.60170 11.95410
39 -84.05870 1.00000 1.71473 34.0
40 39.52550 11.23460 1.75520 27.6
41 -74.82140 10.91620
42 -56.28710 1.00000 1.88300 40.8
43 58.81270 3.90000
44 71.15110 11.03710 1.51633 64.1
45 -38.43710 2.40000
46 1128.10480 5.90110 1.58604 62.2
47 -91.82070 6.77000
48 42.11920 5.75250 1.48749 70.2
49 257.31740 2.80000
50 -81.40980 1.30000 1.58610 40.5
51 140.21670 41.00000
52 ∞ 5.00000 1.51680 64.2
53 ∞ 1.00000
54 ∞ BF
Image plane ∞
Data 12 (Aspherical data)
10th page
K = -9.89684E-01, A4 = -1.72743E-08, A6 = -1.74597E-12, A8 = 5.03362E-16
A10 = -1.14997E-19, A12 = 1.04838E-23
19th page
K = -1.00000E + 02, A4 = 1.53284E-06, A6 = -5.76575E-10, A8 = 9.56858E-13
A10 = -1.60945E-15, A12 = 1.85224E-18
Data 13 (various data)
Zoom ratio 7.20739
Wide angle infinity Medium infinity Tele infinity Wide angle proximity Medium proximity Telephoto proximity Focal length 30.0000 84.9997 179.9985 31.3364 97.8860 216.2217
F number 2.00005 2.00036 1.99878 2.00010 2.00058 1.99788
Angle of View 27.7800 9.7005 4.6381 25.9956 8.2149 3.4521
Image height 15.0000 15.0000 15.0000 15.0000 15.0000 15.0000
Total lens length 449.9998 449.9997 449.9998 449.9998 449.9998 449.9998
BF 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000
d0 ∞ ∞ ∞ 1550.0000 1550.0000 1550.0000
d2 27.4996 27.4996 27.4996 16.1276 16.1276 16.1276
d7 2.0000 2.0000 2.0000 13.3720 13.3720 13.3720
d14 11.7526 11.7526 11.7526 3.0000 3.0000 3.0000
d18 1.5000 61.8189 88.1371 10.2526 70.5716 96.8897
d26 89.9495 21.8512 4.1100 89.9495 21.8512 4.1100
d29 1.7976 9.5769 1.0000 1.7976 9.5769 1.0000
Entrance pupil position 178.4880 353.8017 525.9726 175.8769 392.1905 664.6752
Exit pupil position -222.9517 -222.9517 -222.9517 -222.9517 -222.9517 -222.9517
Front principal point position 204.4528 406.4038 560.6535 202.7994 446.1179 646.4178
Rear principal point position 420.0882 365.0575 270.0059 418.1824 347.1323 210.2122
Data 14 (single lens data)
Lens Start surface Focal length
1 1 1096.8123
2 3 -159.3330
3 4 212.3309
4 6 -261.6149
5 8 -659.9291
6 9 176.9278
7 11 -253.0809
8 13 298.6476
9 15 251.7153
10 17 359.8222
11 19 -53.4390
12 21 -66.7930
13 23 44.4228
14 25 -79.0149
15 27 -69.6093
16 28 195.0261
17 31 56.5283
18 32 -360.5194
19 34 65.6974
20 35 -65.9599
21 37 146.2345
22 39 -37.4878
23 40 35.7581
24 42 -32.4399
25 44 50.0491
26 46 145.1457
27 48 102.4134
28 50 -87.6888
Data 15 (zoom lens group data)
Group Start surface Focal length Lens construction length Front principal point position Rear principal point position
1 1 1096.81231 8.00000 -7.55071 -4.02581
2 3 -176.84041 44.30070 27.44001 38.04142
3 8 277.02022 46.05030 16.13142 31.29609
4 15 150.43888 26.23950 3.97362 12.05992
5 19 -42.98799 30.12910 2.71670 10.44601
6 27 -108.79325 4.95470 -0.11366 2.15965
7 30 58.36425 154.82620 36.12333 27.66869
(Numerical example 4)
The lens system of Numerical Example 4 corresponds to Embodiment 4 shown in FIG. The surface data of the lens system of Numerical Example 4 is shown as data 16, the aspheric data is shown as data 17, the various data is shown as data 18, the single lens data is shown as data 19, and the zoom lens group data is shown as data 20.
Data 7 (surface data)
Surface number rd nd vd
Surface ∞ Variable
1 692.14790 8.00000 1.48749 70.4
2 500.00000 Variable
3 585.83820 4.00000 1.68634 44.8
4 110.69000 19.76390 1.75418 28.6
5 225.97960 24.81840
6 -254.53590 3.60000 1.48749 70.4
7 -1288.45400 Variable
8 800.00000 3.30000 1.75134 27.7
9 296.59350 17.04940 1.58405 62.4
10 * -351.37260 0.20000
11 224.97680 3.30000 1.75273 30.1
12 133.11640 22.55160 1.43700 95.1
13 -659.45020 0.20000
14 130.34320 21.86790 1.43700 95.1
15 -735.47780 0.20000
16 97.88680 12.05430 1.49700 81.6
17 121.22930 Variable
18 * 1671.83320 1.50000 1.66814 52.5
19 33.51130 12.89800
20 -46.03 180 1.40000 1.56384 63.7
21 117.71070 0.20000
22 77.55420 13.42660 1.75060 32.7
23 -48.35040 1.10000
24 -40.18850 1.30000 1.59495 39.3
25 -152.47610 Variable
26 -61.28420 1.50000 1.68722 45.0
27 113.13430 3.94400 1.92286 18.9
28 658.31010 Variable
29 (Aperture) ∞ 1.80000
30 104.84280 11.78950 1.63882 56.9
31 -50.25540 1.50000 1.62872 36.3
32 -62.54550 0.50000
33 105.86210 12.36610 1.48757 70.4
34 -43.85670 1.50000 2.00069 25.5
35 -132.56560 0.20000
36 60.02360 5.84520 1.62042 60.3
37 253.08560 4.02650
38 -84.52050 1.00000 1.70547 33.6
39 39.79650 12.81440 1.75520 27.6
40 -82.71150 10.69640
41 -60.95630 1.00000 1.88300 40.8
42 50.98230 4.00000
43 66.04750 12.68080 1.53917 65.5
44 -37.24360 3.00000
45 139.75350 3.85350 1.64348 56.1
46 -482.04060 6.77000
47 46.01000 4.42530 1.48749 70.2
48 169.88490 2.80000
49 -97.55110 1.30000 1.62563 35.8
50 228.24190 41.00000
51 ∞ 5.00000 1.51680 64.2
52 ∞ 1.00000
53 ∞ BF
Image plane ∞
Data 17 (Aspherical data)
10th page
K = -4.04386E + 00, A4 = -2.23382E-09, A6 = -5.67700E-13, A8 = 3.37143E-16
A10 = -5.36018E-20, A12 = 3.24895E-24
18th page
K = -1.00000E + 02, A4 = 1.07253E-06, A6 = 3.21919E-11, A8 = 2.59273E-13
A10 = -1.32082E-15, A12 = 1.85224E-18
Data 18 (various data)
Zoom ratio 5.17995
Wide angle infinity Medium infinity Tele infinity Wide angle proximity Medium proximity Telephoto proximity Focal length 29.9999 69.9996 149.9991 27.6061 68.7489 155.3981
F number 1.80003 1.80063 1.79987 1.80017 1.80090 1.79898
Angle of View 27.7974 11.8955 5.6078 30.1899 11.9212 5.0963
Image height 15.0000 15.0000 15.0000 15.0000 15.0000 15.0000
Total lens length 480.0000 479.9999 480.0000 480.0000 479.9999 480.0000
BF 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000
d0 ∞ ∞ ∞ 1520.0000 1520.0000 1520.0000
d2 56.9857 56.9857 56.9857 8.5369 8.5369 8.5369
d7 4.0000 4.0000 4.0000 52.4488 52.4488 52.4488
d17 3.0000 54.5290 84.3625 3.0000 54.5290 84.3625
d25 84.4725 28.2325 4.1100 84.4725 28.2325 4.1100
d28 2.5000 7.2109 1.5000 2.5000 7.2109 1.5000
Entrance pupil position 207.7532 353.5010 532.8317 179.8421 313.4241 509.3872
Exit pupil position -217.4984 -217.4984 -217.4984 -217.4984 -217.4984 -217.4984
Front principal point position 233.6168 400.9759 579.3729 203.9385 360.1843 546.9513
Rear principal point position 450.0855 410.0382 329.9798 452.0338 408.7000 312.0406
Data 19 (single lens data)
Lens Start surface Focal length
1 1 -3745.7104
2 3 -199.5303
3 4 267.9359
4 6 -651.4213
5 8 -629.1021
6 9 278.0721
7 11 -439.9026
8 12 255.6641
9 14 255.3266
10 16 873.1885
11 18 -51.2010
12 20 -58.5091
13 22 41.5795
14 24 -92.1239
15 26 -57.6416
16 27 147.5187
17 30 54.8022
18 31 -426.8989
19 33 65.3711
20 34 -66.0524
21 36 125.3723
22 38 -38.2255
23 39 37.2549
24 41 -31.3099
25 43 46.1539
26 45 168.7785
27 47 127.9390
28 49 -109.0684
Data 20 (zoom lens group data)
Group Start surface Focal length Lens construction length Front principal point position Rear principal point position
1 1 -3745.71044 8.00000 19.64110 22.18851
2 3 -329.67074 52.18230 34.20022 44.89549
3 8 118.14765 80.72320 23.23185 49.82029
4 18 -46.49784 31.82460 0.39555 6.82594
5 26 -94.76795 5.44400 0.21462 2.72842
6 29 55.15678 149.86770 35.27763 31.25080
Table 1 below shows the corresponding values for each condition in the lens system of each numerical example.

（条件の対応値）
以上のように、本開示における技術の例示として、実施の形態を説明した。そのために、添付図面および詳細な説明を提供した。

(Corresponding value of condition)
As described above, the embodiments have been described as examples of the technology in the present disclosure. For this purpose, the accompanying drawings and detailed description are provided.

  Accordingly, among the components described in the accompanying drawings and the detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to illustrate the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  Moreover, since the above-mentioned embodiment is for demonstrating the technique in this indication, a various change, replacement, addition, abbreviation, etc. can be performed in a claim or its equivalent range.

  The present disclosure can be applied to a digital still camera, a digital video camera, a camera of a portable information terminal such as a smartphone, a surveillance camera in a surveillance system, a Web camera, an in-vehicle camera, and the like. In particular, the present disclosure is applicable to a photographing optical system that requires high image quality, such as a digital still camera system and a digital video camera system.

G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group L1 1st lens element L2 2nd lens element L3 3rd lens element L4 4th lens element L5 5th lens element L6 6th lens element L7 7th lens element L8 8th lens element L9 9th lens element L10 10th lens element L11 11th lens element L12 12th lens element L13 13th lens element L14 14th lens element L15 15th lens element L16 16th lens element L17 17th lens element L18 18th lens element L19 19th lens element L20 20th lens element L21 21st lens element L22 22nd lens element L23 23rd lens element L24 24th lens element L25 25th lens element L26 26th lens element L27 27th lens element L28 28th lens element Aperture stop S image plane P parallel plate 100 lens-interchangeable digital camera system 101 camera body 102 image sensor 103 monitor 104 camera mount section 201 interchangeable lens apparatus 202 lens system 203 barrel 204 lens mount portion 205 flange back adjusting mechanism 206 operating unit

Claims (16)

A lens system having a plurality of lens groups each including at least one lens element,
A focus lens group that moves along the optical axis with respect to the image plane during focusing from an infinitely focused state to a close object focused state;
An aberration correction lens group having at least one lens element and moving along the optical axis with respect to the image plane,
The aberration correction lens group is fixed with respect to the focus lens group or the image plane during focusing,
A lens system that satisfies the following condition (1):
0.1 <| f _adj / f _focus | <9.5 (1)
here,
f _adj : focal length of the aberration correction lens group f _focus : focal length of the focus lens group The lens system according to claim 1, which satisfies the following condition (2):
0.05 <| f _adj / f | <2 (2)
here,
f: The focal length of the entire lens system when focused at infinity. The lens system according to claim 1 or 2, which satisfies the following condition (3):
1.5 <| f _adj / H | <30 (3)
here,
H: Image height of the lens system. The lens system according to any one of claims 1 to 3, which satisfies the following condition (4):
0.05 <| f _adj / L | <5 (4)
here,
L: Total optical length of the lens system The lens system according to any one of claims 1 to 4, which satisfies the following condition (5):
0.2 <H × Fno. /F<1.5 (5)
here,
Fno. : F value of the lens system. The lens system according to any one of claims 1 to 5, which satisfies the following condition (6):
0.5 <| f _focus / f | <12 (6)
here,
f _focus : focal length of the focus lens group (when there are a plurality of focus lens groups, the smaller absolute value)
It is. The lens system according to any one of claims 1 to 6, which satisfies the following condition (7):
2 <| f _focus / H | <25 (7) The lens system according to any one of claims 1 to 7, which satisfies the following condition (8):
0.3 <| f _focus / L | <3 (8) The lens system according to claim 1, which satisfies the following condition (9):
0.1 <L _C / L <1 (9)
here,
L _C : Distance on the optical axis from the most image side surface of the aberration correction lens group to the image surface. The lens system according to any one of claims 1 to 9, which satisfies the following condition (10):
1 <L _C / BF <3 (10)
here,
BF: Lens system back focus. The aberration correction lens group is composed of one lens element.
The lens system according to claim 1. An aperture stop,
The aberration correction lens group is disposed closer to the image plane than the aperture stop,
The lens system according to claim 1. A lens system having a plurality of lens groups each composed of at least one lens element, and moves along the optical axis with respect to the image plane during focusing from an infinite focus state to a close object focus state. An aberration correction lens group, and an aberration correction lens group that includes at least one lens element and moves along the optical axis with respect to the image plane. The aberration correction lens group is a focus lens during focusing. It is fixed with respect to the group or / and image plane, and the following condition (1)
0.1 <| f _adj / f _focus | <9.5 (1)
With a lens system that satisfies
A lens mount that can be connected to a camera body having an image sensor,
An interchangeable lens device that acquires a signal from a camera body and moves an aberration correction lens group in accordance with the signal.   The interchangeable lens device according to claim 13, further comprising a back focus adjustment mechanism that changes an air interval from the imaging device to the most image side surface of the lens system by moving the lens system uniformly along the optical axis. It further includes an operation unit,
The aberration correction lens group is moved by the operation unit.
The interchangeable lens apparatus according to claim 13 or 14. The interchangeable lens device according to any one of claims 13 to 15,
A camera system comprising: the interchangeable lens device and a camera body that is detachably connected via a camera mount unit and has an image sensor.

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