JP2018180132A - Image capturing optical system with soft focus feature - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact, light-weight image capturing optical system with a soft focus feature, which is capable of making spherical aberration adjustment without changing a best focus position relative to an image sensor position and screen peripheral performance when performing soft focusing.SOLUTION: An image capturing optical system comprises, in order from the object side to the image side, a front group having negative refractive power as a whole, an aperture stop, and a rear group having positive refractive power as a whole, the rear group including a movable group UA having positive refractive power and being configured to move in an optical axis direction, where a lateral magnification of the movable group UA is appropriately set.SELECTED DRAWING: Figure 1

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an imaging optical system having a soft focusing function provided with an adjusting lens group that is movable to change the depiction of the center of an object. The present invention relates to a lens suitable for a television camera for television broadcasting, a video camera for imaging, a digital camera, a digital cinema and the like, and an imaging device having the same.

  A lens having a so-called soft focus function has been known as a lens for television broadcasting, a digital camera, and a lens for digital cinema. This is a function of changing the performance of the central portion of the screen of the subject image to change the depiction.

  Patent Document 1 discloses a configuration related to an attachment lens having an aberration variable function. The attachment lens is mounted on the image side of the zoom lens or the single focus lens. The attachment lens as a whole has a two-group configuration, and the spherical aberration sensitivity to the change in distance between the first group and the second group is set high. At least one lens group among the plurality of lens groups is moved in the optical axis direction as a spherical aberration adjustment group.

  Patent Document 2 discloses a configuration related to a zoom lens having an aberration variable function. The zoom lens has a four-group configuration, and a movable group that moves along an optical axis for spherical aberration adjustment is provided in a fourth group.

JP 09-189858 A JP 2014-235203 A

  In general, lenses for television broadcasting and digital cinema have high optical performance of central performance (spherical aberration) and high contrast, and in many cases the contour of the object is clear. On the other hand, in the fields such as television broadcasting and digital cinema, in order to make the main subject stand out, the delineability of the central performance (spherical aberration) may be the object of evaluation in an aesthetic point of view. At that time, it is desired to change the contrast without changing the resolution at the center of the screen by changing only the spherical aberration. As this method, an imaging optical system having a so-called soft focus function is known, in which the spherical aberration is varied by changing the distance in the lens.

  However, in an imaging optical system having a soft focus function, when soft focusing is performed, there is a problem that the best focus position is largely deviated with respect to the position of the imaging element, and the resolution feeling is also changed.

  As a countermeasure against these, the shifted best focus position is corrected by moving the other lens units in the optical axis direction. However, there is a problem that the operation becomes complicated because it is necessary for the photographer to move the other lens units separately. In addition, in order to automatically correct the shifted best focus position, there is a problem in cost as it requires a separate mechanical structure and electrical system.

  From the above, in an imaging optical system having a soft focusing function, an imaging apparatus that does not shift the best focus position with respect to the imaging element position when soft focusing is desired is desired.

  In the spherical aberration adjustment device in Patent Document 1, when soft focusing is performed, the best focus position is shifted with respect to the image pickup element position. Since it is necessary to return the deviation of the best focus position, a mechanical structure for integrally moving the objective lens and the attachment lens becomes necessary, which is not preferable from the viewpoint of cost.

  In the spherical aberration adjustment device in Patent Document 2, when soft focusing is performed, the best focus position does not largely shift with respect to the imaging element position. However, the configuration is such that the axial ray converges with respect to the movable group that moves in the optical axis direction for spherical aberration adjustment (the lateral magnification of the movable group is positive), so that the entire front of the diaphragm has negative refraction. In the case of arranging the front group having a force, it becomes difficult to arrange the movable group immediately after the diaphragm. Therefore, since it is necessary to arrange the movable group away from the stop, off-axis aberrations such as curvature of field and the like are simultaneously changed at the time of spherical aberration adjustment, which is not preferable because control of only spherical aberration becomes difficult.

  The present invention has been made in view of such problems. The objective is an imaging optical system having a soft focus function, which is small in size, light weight, and capable of performing spherical aberration adjustment without changing the best focus position and screen peripheral performance with respect to the image sensor position when soft focusing is performed. To provide.

In order to achieve the above object, an imaging optical system according to the present invention is
From the object side to the image side, a front group having a negative refractive power as a whole, an aperture stop, and a rear group having a positive refractive power as a whole, and an optical axis direction having a positive refractive power in the rear group When the lateral magnification of the movable group UA is βa,
−1.20 <βa <−0.80 (1)
It is characterized by satisfying.

  According to the present invention, an imaging optical system having a soft focus function, which is compact and lightweight, and can perform spherical aberration adjustment without changing the best focus position and screen peripheral performance with respect to the image sensor position when soft focusing is performed. You get

FIG. 5 is a cross-sectional view of a zoom lens according to Numerical Embodiment 1 of the present invention when an object at infinity is in focus at the wide-angle end. FIGS. 7A and 7B are longitudinal aberration diagrams before and after movement of the spherical aberration adjustment group at the wide-angle end at the object distance infinity in numerical value example 1, respectively. FIGS. However, the value of the focal length is a value when the numerical example to be described later is expressed in mm. This is all the same in the following numerical examples. It is a lens sectional view when focusing on an infinite distance object at the wide angle end of the zoom lens according to Numerical Embodiment 2 of the present invention. FIGS. 7A and 7B are longitudinal aberration diagrams before and after movement of the spherical aberration adjustment group at the wide-angle end at an object distance of infinity according to Numerical Example 2; FIGS. It is a lens sectional view when focusing on an infinite distance object at the wide angle end of the zoom lens according to Numerical Embodiment 3 of the present invention. FIGS. 7A and 7B are longitudinal aberration diagrams before and after movement of the spherical aberration adjustment group at the wide-angle end at an object distance of infinity according to Numerical Example 3; FIGS. FIG. 6 is a ray diagram at the wide angle end of the zoom lens of Numerical Embodiment 1. It is a principal part schematic diagram of an imaging device of the present invention.

  In the aberration diagrams of Numerical Embodiments 1 to 3, spherical aberration is represented by e-line and g-line. The astigmatism is represented by a meridional image plane (ΔM) of the e-line and a sagittal image plane (ΔS) of the e-line. Lateral chromatic aberration is represented by g-line.

  In the aberration diagrams of Numerical Embodiments 1 to 3, the spherical aberration is 0.2 mm, the astigmatism is 0.2 mm, the distortion is 5%, and the lateral chromatic aberration is drawn on a scale of 0.05 mm. Fno is an F number, and ω is a half angle of view. The wide-angle end and the telephoto end refer to zoom positions when the second lens unit U2 for zooming is located at both ends of the movable range on the optical axis.

  Next, features of each numerical example will be described.

  The imaging optical system of the present invention comprises, in order from the object side to the image side, a front group having negative refractive power as a whole, an aperture stop, and a rear group having positive refractive power as a whole. Furthermore, the rear group has a movable group that moves in the optical axis direction having a positive refractive power. Here, the refractive power is defined as the reciprocal of the focal length.

  FIG. 1 is a cross-sectional view of a zoom lens according to Numerical Embodiment 1 of the present invention when an object at infinity is in focus at the wide-angle end.

  UF is a front group having negative refractive power as a whole. UF is composed of U1, U2 and U3. U1 is a first lens group of positive refractive power which does not move during zooming. A part of the first lens group moves from the object side to the image side during focus adjustment from infinity to a finite distance. U2 is a second lens unit (variator lens unit) of negative refractive power for zooming that moves toward the image side during zooming from the wide-angle end (short focal length end) to the telephoto end (long focal length end). U3 is a third lens unit (compensator lens unit) of negative refractive power that moves in conjunction with the second lens unit U2 and corrects the image plane variation accompanying the magnification change. SP is an aperture stop. UR is a rear group having a positive refractive power as a whole. UR has UA, UB, and FB. UA is a movable group having positive refractive power and moving in the optical axis direction for spherical aberration adjustment when performing soft focusing. UB is a movable group which is sandwiched by the afocal distance and moves in the optical axis direction for adjusting the curvature of field. The UBF is a movable group to which parallel light beams are incident and which moves in the optical axis direction for back focus adjustment having positive refractive power. IP is an image plane and corresponds to an imaging surface of an imaging device (photoelectric conversion device).

  In Numerical Embodiment 2, the group configurations of UF, U1, U2, U3, UR, UA, UB, and UBF are all the same as in Numerical Embodiment 1.

  In Numerical Embodiment 3, the group configurations of U1, U2, UA, and UBF are all the same as in Numerical Embodiment 1. U3 is a third lens unit of positive refractive power which moves in conjunction with U2 and corrects the image plane variation accompanying the magnification change.

  Next, the lens configuration of each group in Numerical Embodiment 1 will be described. Hereinafter, each lens is assumed to be disposed in order from the object side to the image side.

  U1 is composed of two negative lenses, two positive lenses, a negative lens, a positive lens, a cemented lens of a negative lens and a positive lens, and two positive lenses. U2 is composed of a negative lens, a negative lens, a cemented lens of a positive lens and a negative lens, and a positive lens. U3 is composed of a cemented lens of a negative lens and a positive lens. UR is composed of UA, negative lens, UB and UBF. UA is composed of a positive lens, a cemented lens of a positive lens and a negative lens, and two positive lenses. UB is composed of a cemented lens of a negative lens and a positive lens, a negative lens, and a positive lens. The UBF is composed of a positive lens and a cemented lens of a positive lens and a negative lens.

  The lens configuration of each group in Numerical Embodiment 2 is the same as that in Numerical Embodiment 1.

  Next, the lens configuration of each group in Numerical Embodiment 3 will be described. U1 is composed of two negative lenses, two positive lenses, a cemented lens of a negative lens and a positive lens, and a positive lens. U2 is composed of two negative lenses, a positive lens and a negative lens. U3 is composed of a single positive lens and a cemented lens of a positive lens and a negative lens. UR is composed of a positive lens, a negative lens, a UA, a cemented lens of a positive lens and a negative lens, and a UBF. UA is composed of a positive lens. The UBF is composed of a positive lens, a negative lens and a positive lens.

  When the spherical aberration adjustment group UA is moved in the optical axis direction at the time of soft focusing, if not only the spherical aberration but also the back focus is largely changed, the best focus position is largely deviated with respect to the image pickup element position.

The back focus change amount Δsk when the i-th lens unit is moved by a small unit in the optical axis direction from the normal position in the lens system including the first to k-th lens units has a lateral magnification of β _i When the lateral magnification of the i-th group and thereafter is β _{i + 1} to _k , it is defined by the following equation.

From the equation (1), in the case of β _i = ± 1, the back focus does not change even if the i-th group is moved in the optical axis direction. Therefore, in order to suppress the back focus change when moving the movable group UA in the optical axis direction and to reduce the deviation of the best focus position with respect to the image sensor position during soft focusing, the lateral magnification βa of the movable group UA ≒ 1. Or βa ≒ −1.

  FIG. 7 is a ray diagram at the wide-angle end of the zoom lens according to Numerical Embodiment 1. FIG. If the movable group is disposed at a position distant from the stop, off-axis aberrations such as curvature of field and the like are simultaneously changed at the time of spherical aberration adjustment, which is not preferable because control of only spherical aberration becomes difficult.

  As shown in FIG. 7, in the case where a front group having a negative refractive power as a whole before throttling is disposed, if a movable group UA having a positive refractive power is to be disposed immediately after the throttling, on-axis relative to the movable group UA. A ray is divergent and enters. Furthermore, in order to miniaturize the rear group UR, in order to cause the movable group UA to eject with convergence, it is sufficient to set βa ≒ −1.

  The lateral magnification βa of the movable unit UA is defined by the conditional expression (1). Above the upper limit value of conditional expression (1) or below the lower limit value, at the time of soft focusing, back focus change when moving the movable unit UA in the optical axis direction is suppressed, and the best focus position with respect to the image sensor position It becomes difficult to reduce the deviation. More preferably, conditional expression (1) may be set as follows.

−1.12 <βa <−0.88 (1a)
By satisfying the above configuration, the imaging optical system of each numerical value example of the present invention is compact and lightweight, and does not change the best focus position and screen peripheral performance with respect to the imaging element position when soft focusing is performed. Spherical aberration adjustment can be performed.

  As a further embodiment of the present invention, the ratio of the focal length fa of the movable group UA and the focal length fr of the rear group UR is defined by conditional expression (2). This defines the spherical aberration sensitivity when moving the movable unit UA.

0.40 <| fa / fr | <1.30 (2)
If the upper limit value of the conditional expression (2) is exceeded, the refractive power of the movable group UA becomes too small with respect to the refractive power of the rear group UR, and the spherical aberration change when moving the movable group UA is not sufficient. Therefore, in order to exert the soft focus effect sufficiently, the amount of movement of the movable group UA becomes too large, which makes it difficult to reduce the size and weight of the lens diameter, and changes in off-axis aberrations such as field curvature. It gets too big.

  Below the lower limit value of the conditional expression (2), the refractive power of the movable group UA becomes too large with respect to the refractive power of the rear group UR, and the spherical aberration sensitivity when moving the movable group UA becomes too high. As a result, it is difficult to control the movement of the movable unit UA in the desired spherical aberration adjustment. More preferably, conditional expression (2) may be set as follows.

0.60 <| fa / fr | <1.10 (2a)
As a further embodiment of the present invention, the conditional expression (3) defines the lateral magnification βar of the group closer to the image than the movable group UA. This defines the spherical aberration sensitivity when moving the movable unit UA. When no lens unit is present on the image side of the movable unit, βar is 1.

0.20 <| βar | <1.80 (3)
When the value exceeds the upper limit value of the conditional expression (3), the spherical aberration generated by the movement of the movable group UA is too large, so that the spherical aberration sensitivity when moving the movable group UA becomes too high. As a result, it is difficult to control the movement of the movable unit UA in the desired spherical aberration adjustment.

  If the lower limit value of the conditional expression (3) is exceeded, the spherical aberration generated by the movement of the movable group UA is reduced too much, so that the spherical aberration change when moving the movable group UA is not sufficient. In order to exert the soft focus effect sufficiently, the amount of movement of the movable group UA becomes too large, so it becomes difficult to make the lens diameter smaller and lighter, and the change in off-axis aberrations such as curvature of field also becomes large. It will pass. More preferably, conditional expression (3) may be set as follows.

0.40 <| βar | <1.40 (3a)
As a further embodiment of the present invention, according to conditional expression (4), the length LIa on the optical axis from the aperture stop to the most image side surface in the movable group UA, the aperture stop to the most image side surface in the rear group UR It defines the ratio of the length LIr on the optical axis. This defines the position at which the movable unit UA is disposed in the rear unit UR.

0.10 <LIa / LIr <0.60 (4)
If the upper limit value of the conditional expression (4) is exceeded, the height from the optical axis of the off-axis ray passing through the movable unit UA increases, so off-axis aberrations such as curvature of field change simultaneously at the time of spherical aberration adjustment. Control of only spherical aberration becomes difficult.

  If the lower limit value of the conditional expression (4) is not reached, the arrangement position of the movable unit UA becomes too close to the aperture stop, so it becomes difficult to secure the moving amount of the movable unit UA for spherical aberration adjustment. More preferably, conditional expression (4) may be set as follows.

0.20 <LIa / LIr <0.50 (4a)
As a further embodiment of the present invention, the rear group UR has a movable group UB which can be adjusted in the field curvature without changing the back focus and the spherical aberration by being sandwiched by the afocal distance and moving in the optical axis direction. It defines what you are doing.

  As shown in FIG. 7, on-axis rays passing through the movable group UB are incident in parallel, and are sandwiched by so-called combined focusing intervals emitted in parallel. On the other hand, an off-axis ray passing through the movable unit UB is obliquely incident and emitted obliquely. Thus, when the movable unit UB is moved in the optical axis direction, spherical aberration and back focus do not change, but curvature of field changes, so that only peripheral performance can be changed. By moving the movable unit UA and the movable unit UB independently in the optical axis direction, spherical aberration adjustment and field curvature adjustment can be performed independently.

  As a further embodiment of the present invention, it is defined that the back focus can be adjusted by moving a part in the rear group UR in the optical axis direction. As shown in FIG. 7, for example, the on-axis light beam enters substantially in parallel, and the back focus adjustment becomes possible by moving the movable unit UBF to be imaged. As a result, when the movable unit UA or the movable unit UB is moved, fine adjustment of the best focus position becomes possible even when the best focus position is slightly displaced with respect to the image pickup device position.

  As a further embodiment of the present invention, the front group UF is, in order from the object side to the image side, a first group U1 of immobile positive refractive power during zooming, and a second group U2 of negative refractive power which moves during zooming. , And at least having a third group U3 of negative refractive power that moves during zooming.

  As a further embodiment of the present invention, the front group UF is, in order from the object side to the image side, a first group U1 of immobile positive refractive power during zooming, and a second group U2 of negative refractive power which moves during zooming. , And at least having a third group U3 of positive refractive power that moves during zooming.

  Table 1 shows values corresponding to the conditional expressions in Numerical Embodiments 1 to 3. Here, ffw is the focal length of the front group UF at the wide angle end. Numerical Embodiments 1 to 3 satisfy the conditional expressions (1) to (4). As a result, the imaging optical system of the present invention is compact and lightweight, and when soft focusing is performed, spherical aberration adjustment can be performed without changing the best focus position and screen peripheral performance with respect to the image sensor position.

  The outline of an imaging apparatus (television camera system) using each numerical example as a photographing optical system will be described with reference to FIG. FIG. 8 is a schematic view of the essential parts of the imaging device of the present invention. In FIG. 8, reference numeral 101 denotes a zoom lens according to any one of Numerical Embodiments 1 to 3. 123 is a camera. The zoom lens 101 is attachable to and detachable from the camera 123. Reference numeral 124 denotes an imaging device configured by mounting the zoom lens 101 on the camera 123.

  The zoom lens 101 has a first lens unit U1, a variable magnification unit LZ, and a relay unit LR. The variable magnification group LZ includes a focusing lens group. The zoom unit LZ includes a group moving on the optical axis for changing magnification, and a group moving on the optical axis to correct the image plane variation accompanying the changing magnification. An aperture stop SP is provided between the variable magnification group LZ and the relay group LR.

  Reference numeral 115 denotes a drive mechanism such as a helicoid, a cam, or an actuator for driving the magnification varying group LZ in the optical axis direction. Reference numerals 116 and 117 denote motors (driving means) for electrically driving the drive mechanism 115 and the aperture stop SP. Reference numerals 118 and 119 denote detectors such as an encoder, a potentiometer, or a photo sensor for detecting the position on the optical axis of the magnification changing unit LZ and the diameter of the aperture stop SP. In the camera 123, 109 is a glass block corresponding to an optical filter or color separation prism in the camera 123, and 110 is an imaging element (photoelectric conversion element) such as a CCD sensor or CMOS sensor that receives an object image formed by the zoom lens 101 It is. Reference numerals 111 and 120 denote CPUs that control various driving operations of the camera 123 and the zoom lens main body 101.

  By applying the imaging optical system of the present invention to a television camera as described above, an imaging apparatus having high optical performance is realized.

  In the following numerical examples, r is the radius of curvature of each surface from the object side, d is the distance between each surface, and nd and dd are the refractive index and Abbe number of each optical member.

The aspheric surface shape is X axis in the optical axis direction, H axis in the direction perpendicular to the optical axis, light traveling direction is positive, R is paraxial radius of curvature, k is conical constant, A3, A4, A5, A6, A7, Assuming that A8, A9, A10, A11, A12, A13, A14, A15, and A16 are respectively aspheric coefficients, they are expressed by the following equations.

Is represented by Also, for example, "e-Z" means " ^x10 -z". * Indicates that it is an aspheric surface.

Numerical Embodiment 1
Unit mm

Surface data surface number rd nd vd effective diameter
1 * 329.458 4.00 1.77250 49.6 107.50
2 43.810 29.19 78.68
3 -208.853 3.20 1.77250 49.6 78.33
4 101.030 3.54 77.91
5 106.765 11.45 1.80809 22.8 80.33
6 4092.086 7.87 80.20
7 226.464 10.64 1.51633 64.1 79.66
8 * -160.227 1.41 79.04
9 678.153 3.00 1.80518 25.4 77.24
10 125.022 3.22 76.45
11 112.012 14.01 1.48749 70.2 78.25
12 -195.916 11.48 78.31
13 2253.200 3.00 1.72047 34.7 78.40
14 98.945 14.03 1.49700 81.5 78.56
15 -233.338 0.20 78.94
16 563.545 11.38 1.60311 60.6 79.22
17 * -110.630 0.20 79.16
18 660.645 9.62 1.43387 95.1 75.25
19 -119.575 (variable) 74.30
20 78.175 1.60 1.90366 31.3 41.61
21 33.265 8.41 37.20
22-67.990 1.50 1.61800 63.3 37.11
23 53.427 2.94 35.89
24 90.036 6.90 1.73800 32.3 36.17
25 -62.143 1.50 1.72916 54.7 35.97
26 185.277 0.20 35.55
27 59.228 3.55 1.71736 29.5 35.54
28 188.673 (variable) 35.11
29-54.377 1.50 1.75500 52.3 31.65
30 72.533 3.86 1.84666 23.8 33.57
31 4728.820 (variable) 34.12
32 (Aperture) ∞ 3.00 35.23
33 6789.500 3.48 1.77250 49.6 36.89
34 -119.717 0.20 37.49
35 135.343 8.98 1.51633 64.1 38.36
36-38.860 1.40 1.84666 23.8 38.58
37 -181.038 8.24 40.05
38 57.183 8.05 1.77250 49.6 44.41
39-373. 934 1.33 43. 84
40 33.762 9.98 1.48749 70.2 40.00
41 42.682 7.50 34.63
42 76.388 1.60 2.00069 25.5 30.89
43 30.959 4.50 28.91
44 40.975 1.50 2.00069 25.5 28.65
45 19.020 7.82 1.92286 18.9 27.34
46-3337.262 6.60 27.10
47 -36.607 1.20 2.00330 28.3 26.06
48 59.728 0.56 27.42
49 48.486 6.49 1.49700 81.5 28.88
50-73.847 4.00 30.15
51 183.116 5.37 1.72916 54.7 33.25
52 -60.392 0.20 33.68
53 63.467 8.32 1.49700 81.5 33.29
54-35.056 1.20 1.84666 23.8 32.82
55 -196.175 45.29 32.92
Image plane ∞

Aspheric data first surface
K = 2.77448e + 001 A 4 = 7.07945e-007 A 6 = -1.51592e-010 A 8 = 3.08626e-014 A10 = -4.14364 -018 A12 = -2.43544e-022

Eighth side
K = 5.77686e + 000 A 4 = 1.04722e-006 A 6 = -2.16014e-011 A 8 =-8.18 2 82e-015
A10 = 3.49847e-018 A12 = -1.11763e-021

17th
K = 1.83997 e + 000 A 4 = 2.31231 e-007 A 6 = 7.57152 e-011 A 8 = 2.92135 e-015 A10 = -1.81794 e-018 A12 = 1.66263 e-021

Various data Zoom ratio 4.00
Wide-angle Intermediate telephoto focal length 15.00 30.00 60.00
F number 2.37 2.37 2.37
Half angle of view 43.23 25.17 13.22
Image height 14.10 14.10 14.10
Lens total length 382.76 382.76 382.76
BF 45.29 45.29 45.29

d19 0.96 33.26 55.12
d28 50.77 18.22 5.39
d31 10.82 11.07 2.04

Entrance pupil position 50.67 65.50 84.44
Exit pupil position -150.79 -150.79 -150.79
Front principal point position 64.52 90.91 126.08
Rear principal point position 30.29 15.29-14.71

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear side principal point position
1 1 49.30 141.45 70.01 63.23
2 20-45.00 26.59 1.37-19.68
3 29 -78.20 5.36 -0.05-2.98
4 32 53.63 101.51 31.19 -76.25

Single lens data lens Start surface Focal length
1 1 -65.50
2 3 -87.33
3 5 134.10
4 7 182.78
5 9-189.08
6 11 147.91
7 13-142.75
8 14 141.38
9 16 153.71
10 18 233.65
11 20 -64.70
12 22-48.00
13 24 50.43
14 25 -63.38
15 27 118.03
16 29 -40.77
17 30 86.12
18 33 151.59
19 35 59.30
20 36 -58.13
21 38 64.42
22 40 241.47
23 42 -52.47
24 44 -36.40
25 45 20.27
26 47 -22.29
27 49 59.77
28 51 62.60
29 53 46.61
30 54-50.09

Numerical Embodiment 2
Unit mm

Surface data surface number rd nd vd effective diameter
1 * 329.458 4.00 1.77250 49.6 107.50
2 43.810 29.19 78.68
3 -208.853 3.20 1.77250 49.6 78.33
4 101.030 3.54 77.91
5 106.765 11.45 1.80809 22.8 80.33
6 4092.086 7.87 80.20
7 226.464 10.64 1.51633 64.1 79.66
8 * -160.227 1.41 79.04
9 678.153 3.00 1.80518 25.4 77.24
10 125.022 3.22 76.45
11 112.012 14.01 1.48749 70.2 78.25
12 -195.916 11.48 78.31
13 2253.200 3.00 1.72047 34.7 78.40
14 98.945 14.03 1.49700 81.5 78.56
15 -233.338 0.20 78.94
16 563.545 11.38 1.60311 60.6 79.22
17 * -110.630 0.20 79.16
18 660.645 9.62 1.43387 95.1 75.25
19 -119.575 (variable) 74.30
20 78.175 1.60 1.90366 31.3 41.61
21 33.265 8.41 37.20
22-67.990 1.50 1.61800 63.3 37.11
23 53.427 2.94 35.89
24 90.036 6.90 1.73800 32.3 36.17
25 -62.143 1.50 1.72916 54.7 35.97
26 185.277 0.20 35.55
27 59.228 3.55 1.71736 29.5 35.54
28 188.673 (variable) 35.11
29-54.377 1.50 1.75500 52.3 31.65
30 72.533 3.86 1.84666 23.8 33.57
31 4728.820 (variable) 34.12
32 (Aperture) ∞ 3.00 35.23
33 6789.500 3.67 1.77250 49.6 36.90
34-105.513 0.20 37.49
35 147.661 8.70 1.51633 64.1 38.28
36-39.714 1.40 1.84666 23.8 38.46
37 -126.365 0.19 39.69
38 46.671 6.86 1.77250 49.6 41.01
39 -1753.261 3.20 40.40
40 38.209 7.90 1.48749 70.2 35.86
41 44.198 7.50 31.24
42 375.575 1.60 2.00069 25.5 27.70
43 38.984 4.50 26.31
44 50.132 1.50 2.00069 25.5 26.08
45 20.952 8.05 1.92286 18.9 25.22
46 -96.291 2.76 25.19
47-42.417 1.20 2.00330 28.3 24.71
48 45.581 1.84 25.55
49 45.188 6.51 1.49700 81.5 28.21
50-107.562 4.39 29.57
51 944.965 4.76 1.72916 54.7 32.29
52 -62.185 0.20 32.93
53 46.567 8.96 1.49700 81.5 33.24
54-37.221 1.20 1.84666 23.8 32.80
55 -196.175 45.37 32.90
Image plane ∞

Aspheric data first surface
K = 2.77448e + 001 A 4 = 7.07945e-007 A 6 = -1.51592e-010 A 8 = 3.08626e-014 A10 = -4.14364 -018 A12 = -2.43544e-022

Eighth side
K = 5.77686e + 000 A 4 = 1.04722e-006 A 6 = -2.16014e-011 A 8 =-8.18 2 82e-015
A10 = 3.49847e-018 A12 = -1.11763e-021

17th
K = 1.83997 e + 000 A 4 = 2.31231 e-007 A 6 = 7.57152 e-011 A 8 = 2.92135 e-015 A10 = -1.81794 e-018 A12 = 1.66263 e-021

Various data Zoom ratio 4.00
Wide-angle Intermediate telephoto focal length 15.00 30.00 60.00
F number 2.37 2.37 2.37
Half angle of view 43.23 25.17 13.22
Image height 14.10 14.10 14.10
Lens total length 371.42 371.42 371.42
BF 45.37 45.37 45.37

d19 0.96 33.26 55.12
d28 50.77 18.22 5.39
d31 10.82 11.07 2.04

Entrance pupil position 50.67 65.50 84.44
Exit pupil position -143.16 -143.16 -143.16
Front principal point position 64.48 90.72 125.35
Rear principal point position 30.37 15.37 -14.63

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear side principal point position
1 1 49.30 141.45 70.01 63.23
2 20-45.00 26.59 1.37-19.68
3 29 -78.20 5.36 -0.05-2.98
4 32 52.89 90.09 29.87-74.51

Single lens data lens Start surface Focal length
1 1 -65.50
2 3 -87.33
3 5 134.10
4 7 182.78
5 9-189.08
6 11 147.91
7 13-142.75
8 14 141.38
9 16 153.71
10 18 233.65
11 20 -64.70
12 22-48.00
13 24 50.43
14 25 -63.38
15 27 118.03
16 29 -40.77
17 30 86.12
18 33 133.88
19 35 61.36
20 36 -68.24
21 38 58.67
22 40 402.11
23 42 -43.17
24 44 -36.58
25 45 19.05
26 47-21.57
27 49 64.76
28 51 79.83
29 53 43.03
30 54-53.91

Numerical Embodiment 3
Unit mm

Surface data surface number rd nd vd effective diameter
1 2819.577 2.50 1.69680 55.5 62.11
2 59.290 11.15 57.10
3-124.326 2.20 1.69680 55.5 57.03
4-464.058 7.00 57.54
5 95.930 5.13 1.80809 22.8 62.38
6 159.264 2.50 62.31
7 233.766 9.16 1.48749 70.2 62.76
8-125.630 16.63 63.07
9 110.071 2.85 1.80518 25.4 60.57
10 55.085 13.46 1.49700 81.5 58.42
11 -166.548 0.19 58.10
12 73.755 7.78 1.59522 67.7 55.10
13 678.668 (variable) 53.53
14 33.624 1.43 1.77250 49.6 28.76
15 21.878 5.52 26.20
16-96.001 1.33 1.5891 13 61.1 26.17
17 63.190 0.15 26.30
18 31.036 4.44 1.84666 23.8 26.89
19 76.531 3.25 26.20
20 -47.968 1.24 1.5891 31.1 26.14
21 84.187 (variable) 26.47
22 147.293 4.77 1.5891 13 61.1 26.84
23 -43.788 0.80 27.10
24 -38.708 2.35 1.49700 81.5 27.01
25 -34.285 1.33 1.83400 37.2 27.27
26 -50.187 (variable) 27.85
27 (F-stop) ∞ 1.00 27.88
28 133.573 2.41 1.53775 74.7 27.89
29 303.661 3.17 27.75
30-52.858 2.00 1.88300 40.8 27.70
31 -111.963 5.00 28.35
32 34.735 4.68 1.53775 74.7 30.17
33 147. 976 6. 40 29. 76
34 36.081 3.06 2.10205 16.8 28.05
35 32.409 1.50 1.72825 28.5 26.88
36 27.180 7.16 26.37
37 224.093 4.27 1.59240 68.3 27.98
38 -55.985 10.00 28.36
39 -24.494 1.50 1.90366 31.3 28.31
40-30.331 0.20 29.66
41 70.951 3.41 1.5891 13 61.1 30.99
42 441.746 56.84 30.94
Image plane ∞

Various data zoom ratio 2.86
Wide-angle Intermediate telephoto focal length 35.00 60.01 100.01
F number 2.80 2.80 2.80
Half angle of view 23.95 14.53 8.84
Image height 15.55 15.55 15.55
Lens total length 269.06 269.06 269.06
BF 56.84 56.84 56.84

d13 2.00 26.99 41.07
d21 31.58 20.04 1.49
d26 15.70 2.24 6.71

Entrance pupil position 65.27 97.36 125.33
Exit pupil position -66.94 -66.94 -66.94
Front principal point position 90.37 128.28 144.54
Rear principal point 21.84 -3.17 -43.17

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear side principal point position
1 1 75.40 80.54 60.17 27.36
2 14 -31.25 17.35 9.36 -3.63
3 22 87.50 9.25 3.60-2.63
4 27 76.73 55.80 28.80-20.84

Single lens data lens Start surface Focal length
1 1 -86.58
2 3 -243.33
3 5 285.09
4 7 168.47
5 9-138.92
6 10 84.76
7 12 137.87
8 14 -85.20
9 16 -64.23
10 18 58.43
11 20 -51.49
12 22 57.61
13 24 511.62
14 25-134.03
15 28 439.86
16 30 -114.56
17 32 82.94
18 34 -508.80
19 35 -261.15
20 37 75.78
21 39-159.32
22 41 142.43

U1 first group, U2 second group, U3 third group, UF front group, UR back group,
UA movable group UA, UB movable group UB, UBF movable group UBF, SP aperture stop,
LZ variable power group, LR relay group, IP imaging surface, 101 zoom lens,
109 glass block, 110 imaging device, 111 · 120 CPU,
123 camera, 124 imaging device

Claims (9)

From the object side to the image side, a front group having a negative refractive power as a whole, an aperture stop, and a rear group having a positive refractive power as a whole, and an optical axis direction having a positive refractive power in the rear group When the lateral magnification of the movable group UA is βa,
−1.20 <βa <−0.80
An imaging optical system characterized by satisfying the above. Assuming that the focal length of the movable group UA is fa and the focal length of the rear group is fr,
0.40 <| fa / fr | <1.30
The imaging optical system according to claim 1, wherein When the lateral magnification of the group on the image side of the movable group UA is βar,
0.20 <| βar | <1.80
The imaging optical system according to claim 1 or 2, wherein Assuming that the length on the optical axis from the aperture stop to the most image side surface in the movable group UA is LIa and the length on the optical axis from the aperture stop to the most image side surface in the rear group is LIr
0.10 <LIa / LIr <0.60
The imaging optical system according to any one of claims 1 to 3, wherein   The rear group is characterized by having a movable group UB which can be adjusted in the curvature of field without changing the back focus and the spherical aberration by being sandwiched by the afocal distance and moving in the optical axis direction. The imaging optical system according to any one of claims 4 to 10.   The imaging optical system according to any one of claims 1 to 5, wherein the back focus can be adjusted by moving a part of the rear group in the optical axis direction.   The front group includes, in order from the object side to the image side, a first group of immovable positive refractive power during zooming, a second group of negative refractive power moving during zooming, and a negative power of moving during zooming. The imaging optical system according to any one of claims 1 to 6, comprising at least a third group.   The front group includes, in order from the object side to the image side, a first group of immovable positive refractive power during zooming, a second group of negative refractive power moving during zooming, and a positive power of moving during zooming The imaging optical system according to any one of claims 1 to 6, comprising at least a third group.   An image pickup apparatus comprising: the image pickup optical system according to any one of claims 1 to 8; and an image pickup element for receiving an image formed by the image pickup optical system.