JP2019035792A - Optical system and imaging device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical system capable of reducing the thickness of an imaging device when applied to the imaging device. In order from the object side to the image side, a first lens group having a positive refractive power, a light beam from the first lens group is divided into a plurality of light beams by a reflecting surface and reflected in different directions. And a rear group having a refractive power in the optical path of each of the plurality of light beams divided by the light dividing means, and a focusing means on the image plane side from the light dividing means. [Selection] Figure 1

Description

  The present invention relates to an optical system, for example, an optical system suitable for an imaging apparatus such as a digital still camera, a digital video camera, and a wearable device.

  In recent years, in an imaging apparatus such as a wearable device, it is desired that the entire apparatus is thin. Japanese Patent Application Laid-Open No. 2004-228688 describes an imaging apparatus that provides a pupil dividing unit including a mirror in an optical system and acquires a plurality of parallax images by dividing a light beam into two. Further, Patent Document 2 describes an optical system provided with a reflection unit that bends the optical axis by 90 ° in order to reduce the thickness of the imaging device (Patent Document 2).

JP 2010-81580 A JP 2008-102398 A

  However, since the imaging apparatus described in Patent Document 1 is intended to capture a plurality of parallax images, it is difficult to reduce the size and thickness of the entire optical system.

  In Patent Document 2, one reflecting means for deflecting (bending) the optical path by approximately 90 degrees is used in the optical system. When one reflecting means is used, the thickness of the optical system is affected by the length of the reflecting means in the optical axis direction when the reflecting means is disposed in the optical system. For this reason, the method using one reflecting means has a limit in reducing the thickness direction of the optical system.

  In order to reduce the thickness of the imaging device, it is effective to provide the reflecting means in the optical path of the optical system. However, in order to reduce the thickness of the camera by providing a reflection unit that bends the optical path in the optical path, it is important to appropriately set the configuration of the reflection unit and the lens configuration that constitutes the optical system.

  In particular, in order to reduce the thickness of the imaging apparatus using an optical system having a large pupil diameter, the configuration of the position of the reflecting means in the optical path, the number of reflecting surfaces of the reflecting means, etc., the position of the lens group on the light incident side and the reflecting means It is important to set the relationship properly.

  The present invention can provide an optical system capable of reducing the thickness of the imaging apparatus when applied to the imaging apparatus, and an imaging apparatus using the optical system.

  The optical system of the present invention includes a first lens group having a positive refractive power, a light splitting unit that splits a light beam from the first lens group into a plurality of light beams on a reflecting surface, and reflects them in different directions, and the plurality And a rear group having a refracting power disposed in each optical path, and the rear group includes a focus lens group that moves during focusing.

  ADVANTAGE OF THE INVENTION According to this invention, when applied to an imaging device, the optical system which can make the thickness of an imaging device thin is obtained.

Optical path diagram for explaining the effect of the optical system of the present invention Sectional view of the lens when the optical path of Example 1 is developed Partial lens sectional view of Example 1 Lens sectional view when the optical path of Example 2 is developed Partial lens sectional view of Example 2 Lens sectional view when the optical path of Example 3 is developed Partial lens sectional view of Example 3 Partial lens sectional view of Example 3 Partial lens sectional view of Example 3 Lens sectional view when the optical path of Example 4 is developed Partial lens sectional view of Example 4 Optical path reference diagram showing a conventional optical system Schematic diagram of main parts of an imaging apparatus of the present invention

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. The optical system of the present invention includes a first lens group having a positive refractive power, and a light splitting unit that splits a light beam from the first lens group into a plurality of light beams on a reflecting surface and reflects them in different directions. Further, a rear group having a refractive power is provided in the optical path of each of the plurality of light beams divided by the light splitting means, and the rear group has a focus lens group that moves during focusing. Different object images are formed by a plurality of light beams divided by the light dividing means.

  FIG. 1 is an explanatory view showing the effect of thinning the optical system of the present invention. 2 and 3 are an optical path diagram when the optical path of the first embodiment of the present invention is developed and an optical path explanatory diagram when the light beam is split by the light splitting means. 4 and 5 are an optical path diagram when the optical path according to the second embodiment of the present invention is developed and an optical path explanatory diagram when the light beam is split by the light splitting means. FIG. 6 is an optical path diagram when the optical path of the third embodiment of the present invention is developed. 7 and 8 are optical path explanatory views when the light beam is split by the light splitting means of Embodiment 3 of the present invention. FIG. 9 is a partial perspective view of a part of the third embodiment of the present invention.

  10 and 11 are an optical path diagram when the optical path according to the fourth embodiment of the present invention is developed and an optical path explanatory diagram when the light beam is split by the light splitting means. FIG. 12 is a schematic view of a main part of a conventional optical system. FIG. 13 is a schematic view of the main part of the imaging apparatus of the present invention.

  In each optical path explanatory diagram, L0 is an optical system. L1 is a first lens unit having a positive refractive power. Lpd is a light splitting unit that splits the light beam from the first lens unit L1 into a plurality of light beams on the reflection surface and reflects them in different directions. LR, LR1, and LR2 are light beams having a predetermined refractive power arranged in the optical path of each light beam of the plurality of light beams divided by the light splitting unit Lpd. IP is an image plane on which an image sensor such as a CCD sensor or a CMOS sensor is arranged. LM, LMa, and LMb are each a reflecting member.

  In order to reduce the thickness of the image pickup apparatus, an optical system using a reflecting element unit that bends the optical path of the optical system by approximately 90 degrees is known. However, in an optical system having a large pupil diameter, such as a telephoto lens and a large-diameter lens, the thickness of the optical system is substantially proportional to the pupil diameter. For this reason, when an optical system having a large pupil diameter is used, it is difficult to reduce the thickness of the imaging apparatus.

  The optical system L0 of the present invention has, in order from the object side to the image side, a first lens unit L1 having a positive refractive power, a light splitting unit Lpd for splitting a light beam emitted from the first lens unit L1, and a predetermined refractive power. Has rear group LR.

  The optical system L0 of the present invention is arranged on the image side of the first lens unit L1 having a positive refractive power and having a positive refractive power, and an optical pupil splitting unit comprising a plurality of reflecting surfaces is arranged at or near the pupil position. And the optical path is deflected in a plurality of directions. As a result, the thickness direction of the optical system L0 is reduced as shown in FIG.

  The effect of thinning at this time will be described with reference to FIGS. FIG. 12 is a schematic diagram of a main part of the optical system L0 when the incident optical path is bent using the conventional reflecting means LMO having one reflecting surface. The focal length and the aperture of the first lens unit L1 shown in FIGS. 1 and 12 are the same.

  In FIG. 12, reflecting means LM0 for deflecting the optical path by approximately 90 degrees is arranged on the image side of the first lens unit L1 having a positive refractive power. In this configuration, the thickness direction of the optical system L0 is affected by the size of the reflecting means LM0.

  On the other hand, FIG. 1 is a schematic view of the main part of the basic configuration of the optical system L0 of the present invention. In FIG. 1, a light splitting means Lpd comprising a plurality of reflecting surfaces for deflecting each light beam by approximately 90 degrees while dividing the light beam into a plurality of light beams at or near the image-side pupil position of the first lens unit L1 having a positive refractive power. It is arranged. The light splitting means Lpd is arranged at or near the pupil of the optical system L0. By arranging such light splitting means, the thickness direction of the optical system L0 is reduced.

  As can be seen from FIGS. 1 and 12, the optical system L0 is thinner in FIG. Here, in FIG. 1, the light splitting means Lpd including two reflecting surfaces is used for deflecting the optical path, but the number of reflecting surfaces may be any number. When the optical path is deflected, the optical path deflection angle is preferably 90 ° ± 10 ° from the viewpoint of reducing the thickness of the optical system L0.

That is, the angle formed by the optical axis of the first lens unit L1 and the optical axis of the rear unit LR is θ. At this time,
80 ° <θ <100 °
It is good to satisfy the following conditional expression. When the deflection angle exceeds this range, the thinning effect of the optical system by the light splitting means Lpd is not good.

  In the optical system L0 of the present invention, a focus mechanism is disposed when focusing from infinity to a close-range object. In general, a telephoto optical system with a large pupil diameter or a large aperture optical system has a shallow depth of field. For this reason, it is preferable to use a focus mechanism. Further, the focus mechanism is disposed on the image plane side with respect to the light splitting means Lpd. According to this, in the telephoto optical system with a large pupil diameter, the first lens unit L1 and the light splitting means Lpd having a large lens outer diameter can be fixed at the time of focusing, and the entire imaging apparatus can be downsized. realizable.

  In the optical system of the present invention, various focusing methods can be employed for the focusing operation, such as by moving the lens group, by moving the image sensor, or by disposing an optical element having a variable refractive power in the optical system. In FIG. 1, the configuration in which the optical system is thinned by dividing the incident light beam into two parts is shown. However, the number of light beam divisions is not limited to two, and the structure is further divided into four parts such as four parts. Is also applicable.

  Further, according to this configuration, particularly when the light splitting means Lpd is arranged near the pupil, a parallax image can be acquired by the effect of splitting the light beam. With respect to a plurality of images obtained by the present invention, it is possible to realize stereoscopic vision by using a normal image obtained by reconstructing a pupil as a simple parallax image by simple addition.

  With the above configuration, the optical system L0 of the present invention realizes an optical system in which an imaging apparatus can be easily thinned in an optical system having a large pupil diameter.

  Hereinafter, based on each Example, the more preferable structure of this invention is demonstrated. In the optical system of the present invention, the light splitting means Lpd is configured using a plurality of reflecting surfaces. This makes it possible to realize splitting and deflection of the light beam at or near the pupil with a simple and minimal loss of light quantity. In Examples 1 to 3, a reflection surface is used, and in Example 4, a total reflection surface is used.

  Here, in each embodiment, the distance on the optical axis from the vertex of the object side surface of the first lens unit L1 to the reflecting surface of the light splitting means Lpd (the position of Lpd2 described later) is DR, and the focal length of the entire optical system is When f is assumed, the arrangement satisfies the following conditional expression.

0.1 <DR / f <0.5 (1)
By optimizing the arrangement of the light splitting means Lpd, the entire optical system L0 is thinned.

  If the upper limit of conditional expression (1) is exceeded, the arrangement of the light splitting means Lpd will be too much on the image plane side. At this time, the thinning effect due to the optical path division of the large-aperture optical system cannot be exhibited. On the other hand, if the lower limit is exceeded, the arrangement of the light splitting means Lpd is too far on the object side, the light splitting means Lpd is enlarged, and the required surface accuracy of the reflecting surface is too high.

More preferably, the numerical range of conditional expression (1) is set to the following range.
0.15 <DR / f <0.40 (1a)

More preferably, the numerical range of conditional expression (1a) is set to the following range.
0.2 <DR / f <0.3 (1b)

  In each embodiment, the rear group LR is arranged with a refractive power on the image side of the light splitting means Lpd. In order to reduce the thickness of the optical system, it is important to arrange the first lens unit L1 having a positive refractive power as thin as possible. In this case, in order to realize sufficient aberration correction while sharing the refractive power of the entire optical system L0, it is preferable to arrange a rear group LR having refractive power on the image side of the light splitting means Lpd.

  In the second and third embodiments, the reflecting member LM in each optical path is arranged on the image side of the light dividing unit Lpd. By disposing the reflecting member LM, further downsizing of the imaging device and simplification of the focusing mechanism are realized. In the second embodiment, the image member is deflected to the first lens surface L1 side by disposing the reflecting member LM immediately before the image surface. The thickness of the imaging apparatus is minimized by adopting a configuration in which the imaging element is arranged in the space on the first lens unit L1 side having a positive refractive power. In the third embodiment, the reflecting member LM is disposed immediately after the light splitting means Lpd, and the rear group LR is disposed on the image side thereof.

  Here, the reflecting member LM deflects the optical axis in the twisting direction with respect to the optical axis deflected by the light splitting means Lpd. According to this, the rear group LR can be arranged in the same direction within the same plane. At this time, when the rear group LR is a focus lens group, the focus group mechanism can be integrated in a plurality of optical paths after the light beam split, and the focus mechanism can be simplified.

  Although not shown in each drawing, the rear group LR preferably cuts the lens outer diameter into a non-circular shape. In general, the light beam diameter of the light beam incident on the image-side lens group from the light splitting means Lpd is not circular, so that cutting the region other than the effective light beam diameter does not affect the optical performance. Here, if the outer diameter of the lens is cut, a space for arranging various mechanical mechanisms such as a focus mechanism can be secured, and further downsizing of the imaging apparatus can be facilitated.

[Example 1]
Hereinafter, the optical system of Example 1 of the present invention will be described with reference to FIGS. In FIG. 2, Lpd1, Lpd2, and Lpd3 each correspond to the position in the optical axis direction of the reflecting surface of the light splitting means Lpd in FIG.

  The optical system L0 according to the first exemplary embodiment includes, in order from the object side to the image side, a first lens unit L1 having positive refractive power, a light splitting unit Lpd, and a rear unit LR. FIG. 2 shows an optical path diagram in which the optical path is developed. FIG. 3 shows one optical path diagram divided by the light splitting means Lpd of the optical system L0. As the light dividing means, a plurality of reflecting surfaces are employed.

  In addition, by arranging the rear group LR having refractive power on the image side of the light splitting means Lpd, the aberration is favorably corrected in the entire optical system. For focusing from infinity to a short distance, a front lens focus method for moving the first lens unit L1 toward the object side, a rear focus method for moving the rear lens group LR, a method for moving the imaging surface, etc. are adopted. Also good.

  By optimizing the refractive power arrangement of each lens group, the lens configuration in each lens group, the focusing lens group, and the like, an optical system with good focusing performance is obtained.

[Example 2]
The optical system according to Example 2 of the present invention will be described below with reference to FIGS. In FIG. 4, Lpd1, Lpd2, and Lpd3 each correspond to the position in the optical axis direction of the reflecting surface of the light splitting means Lpd in FIG. In FIG. 4, LM1, LM2, and LM3 each correspond to the position in the optical axis direction of the reflecting surface of the reflecting member LM in FIG. FIG. 4 shows an optical path diagram in which the optical path is developed. FIG. 5 shows one optical path diagram divided by the light splitting means Lpd of the optical system L0.

  The second embodiment includes a reflecting member that reflects the light beam from the rear group LR toward the object side. The optical system L0 of the second embodiment is different from the first embodiment in that a reflecting member LM is provided on the image side of the rear group LR, and other configurations and focus methods are the same as those of the first embodiment.

  In the second embodiment, as compared with the first embodiment, the reflecting member LM is disposed immediately before the image plane IP on the image side of the rear group LR. In the second embodiment, the configuration in which the reflecting member is disposed immediately before the image plane IP and the imaging surface is disposed in the direction of the first lens unit L1 makes it possible to effectively use the space and further reduce the size of the imaging apparatus.

[Example 3]
The optical system according to Example 3 of the present invention will be described below with reference to FIGS. In FIG. 6, Lpd1, Lpd2, and Lpd3 each correspond to the position in the optical axis direction of the reflecting surface of the light splitting means Lpd in FIG. In FIG. 6, LM1, LM2, and LM3 each correspond to the position in the optical axis direction of the reflecting surface of the reflecting member LMa in FIG. FIG. 6 shows an optical path diagram in which the optical path is developed. FIG. 7 shows one optical path diagram divided by the light splitting means Lpd of the optical system L0.

  In the third embodiment, the reflecting member LM (LMa, LMb) is disposed in the optical path of the plurality of light beams divided by the light dividing unit Lpd, and the light beam reflected by the reflecting member is guided to the rear group LR. The optical system L0 of the third embodiment is different from the first embodiment in that a reflecting member LM (LMa, LMb) is provided on the image side adjacent to the light splitting means Lpd, and the other configuration is the same as that of the first embodiment.

  In FIG. 8, the light splitting means Lpd splits the light into two light beams. One light beam split by the light splitting means Lpd is reflected downward by the reflecting member LMa and enters the rear group LRa. FIG. 9 shows a perspective view at this time. The other light beam split by the light splitting means Lpd is reflected upward by the reflecting member LMb and enters the rear group LRb.

  The optical axis of the first lens unit L1 and the optical axis of the rear unit LR (LR1, LR2) are located in a plane orthogonal to each other. That is, the plane formed by the optical axis of the first lens unit L1 and the first reflected optical axis when the light beam on the optical axis of the first lens unit L1 is reflected by the light splitting means Lpd is defined as the first plane. . With respect to the first plane, a second plane formed by the first reflected optical axis and the second reflected optical axis when the light beam on the first reflected optical axis is reflected by the reflecting member LM (LMa, LMb). Are orthogonal.

  In the third embodiment, the plurality of rear groups LR (LRa, LRb) arranged in each optical path are bent by the reflecting members LM1, LM2 in the twist direction with respect to the direction in which the optical axis is deflected by the light splitting means. The configuration is arranged in the same plane. At this time, the focus mechanism is integrated by using the rear lens group LR as the focus lens group.

[Example 4]
Hereinafter, an optical system according to Example 4 of the present invention will be described with reference to FIGS. In FIG. 10, Lpd1, Lpd2, and Lpd3 each correspond to the position in the optical axis direction of the reflecting surface of the light splitting means Lpd in FIG. FIG. 10 shows an optical path diagram in which the optical path is developed. FIG. 11 shows one optical path diagram divided by the light splitting means Lpd of the optical system L0.

  The optical system L0 of the fourth embodiment is different from the first embodiment in that one reflection surface of the light splitting means Lpd uses a total reflection prism, and other configurations and focus methods are the same as those of the first embodiment. The fourth embodiment employs a total reflection surface of a total reflection prism as the reflection surface of the light splitting means Lpd as compared with the first embodiment. By using the total reflection surface as the light splitting means, the light splitting and the light beam deflection are performed without losing the amount of light.

  As described above, according to each embodiment, it is possible to easily reduce the thickness of the imaging apparatus even when an optical system having a large pupil diameter is used.

  In the optical system of each embodiment, when correcting image blur due to camera shake, it is preferable to move any of the lenses in a direction including a component perpendicular to the optical axis. In addition, a configuration for displacing the image sensor may be applied.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  Next, an embodiment of a digital camera (imaging device) using the optical system L0 of the present invention will be described with reference to FIG. In FIG. 13, 20 is a digital camera body, and 21 is an imaging optical system constituted by the optical system of the above-described embodiment. Lpd is a light splitting means. The imaging optical system 21 forms an image of a subject on a solid-state imaging element (photoelectric conversion element) 22a and 22b such as a CCD. Reference numeral 23 denotes a recording means for recording the image of the subject received by the image sensors 22a and 22b, and 24 denotes a finder for observing an image displayed on a display element (not shown).

  The display element is composed of a liquid crystal panel or the like, and is displayed by synthesizing images formed on the imaging elements 22a and 22b. As described above, by applying the optical system of the present invention to a digital camera or the like, a portable imaging device with a thin camera thickness is realized.

  Next, numerical data 1 to 4 according to the first to fourth embodiments of the present invention are shown. In each numerical data, i indicates the order of the surfaces from the object side, and ri is the radius of curvature of the lens surface. di is a lens thickness and an air space between the i-th surface and the (i + 1) -th surface. ndi and νdi denote the refractive index and Abbe number for the d-line, respectively. * Indicates an aspherical surface. K, A4, A6, A8, and A10 are aspherical coefficients.

The aspherical shape is defined as x = (h ² / R) / [1+ {1− (1 + k) (h) where x is the displacement in the optical axis direction at the position of the height h from the optical axis with respect to the surface vertex. / R) ² } ^1/2 ] + A4 · h ⁴ + A6 · h ⁶ + A8 · h ⁸ + A10 · h ¹⁰
It is represented by Where R is the paraxial radius of curvature. BF is a back focus, which is a distance from the final lens surface to the image plane. The total lens length is a value obtained by adding back focus to the distance from the first lens surface to the final lens surface.

(Numeric data 1)
Unit mm

Surface data surface number rd nd νd Effective diameter
1 39.548 3.53 1.59282 68.6 14.24
2 -40.527 1.08 1.74950 35.3 13.93
3 -103.483 2.00 13.79
4 ∞ 3.18 15.00
5 ∞ 3.18 15.00
6 ∞ 13.91 15.00
7 -7.576 1.08 1.68893 31.2 8.18
8 -25.686 0.10 8.86
9 -29.298 3.80 1.76802 49.2 8.91
10 * -8.802 26.45 9.83
Image plane ∞

Aspheric data 10th surface
K = 1.21150e-001 A 4 = 1.04023e-004 A 6 = 4.47201e-007 A 8 = 2.53442e-008

Various data Zoom ratio 1.00

Focal length 41.00
F number 2.88
Half angle of view (degrees) 4.18
Statue height 3.00
Total lens length 58.31
BF 26.45

Entrance pupil position 0.00
Exit pupil position -131.44
Front principal point position 30.35
Rear principal point position -14.55

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
L1 1 54.93 4.61 0.66 -2.20
Lpd 4 ∞ 6.36 3.18 -3.18
LR 7 51.62 4.98 12.91 13.36

Single lens Data lens Start surface Focal length
1 1 34.33
2 2 -89.54
3 7 -15.99
4 9 15.16

Conditional expression (1) Numerical value
DR / f = 0.239

(Numeric data 2)
Unit mm

Surface data surface number rd nd νd Effective diameter
1 39.548 3.53 1.59282 68.6 14.24
2 -40.527 1.08 1.74950 35.3 13.93
3 -103.483 2.00 13.79
4 ∞ 3.18 15.00
5 ∞ 3.18 15.00
6 ∞ 13.91 15.00
7 -7.576 1.08 1.68893 31.2 8.18
8 -25.686 0.10 8.86
9 -29.298 3.80 1.76802 49.2 8.91
10 * -8.802 17.29 9.83
11 ∞ 3.54 8.00
12 ∞ 3.54 8.00
13 ∞ 2.09 8.00
Image plane ∞

Aspheric data 10th surface
K = 1.21150e-001 A 4 = 1.04023e-004 A 6 = 4.47201e-007 A 8 = 2.53442e-008

Various data Zoom ratio 1.00

Focal length 41.00
F number 2.88
Half angle of view (degrees) 4.18
Statue height 3.00
Total lens length 58.31
BF 2.09

Entrance pupil position 0.00
Exit pupil position -155.80
Front principal point position 30.35
Rear principal point position -38.91

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
L1 1 54.93 4.61 0.66 -2.20
Lpd 4 ∞ 6.36 3.18 -3.18
LR 7 51.62 4.98 12.91 13.36
LM 11 ∞ 7.07 3.54 -3.54

Single lens Data lens Start surface Focal length
1 1 34.33
2 2 -89.54
3 7 -15.99
4 9 15.16

Conditional expression (1) Numerical value
DR / f = 0.239

(Numerical data 3)
Unit mm

Surface data surface number rd nd νd Effective diameter
1 39.548 3.53 1.59282 68.6 14.24
2 -40.527 1.08 1.74950 35.3 13.93
3 -103.483 2.00 13.79
4 ∞ 3.18 15.00
5 ∞ 3.18 15.00
6 ∞ 2.64 15.00
7 ∞ 3.00 12.00
8 ∞ 3.00 12.00
9 ∞ 5.28 12.00
10 -7.576 1.08 1.68893 31.2 8.18
11 -25.686 0.10 8.86
12 -29.298 3.80 1.76802 49.2 8.91
13 * -8.802 26.45 9.83
Image plane ∞

Aspherical data 13th surface
K = 1.21150e-001 A 4 = 1.04023e-004 A 6 = 4.47201e-007 A 8 = 2.53442e-008

Various data Zoom ratio 1.00

Focal length 41.00
F number 2.88
Half angle of view (degrees) 4.18
Statue height 3.00
Total lens length 58.31
BF 26.45

Entrance pupil position 0.00
Exit pupil position -131.44
Front principal point position 30.35
Rear principal point position -14.55

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
L1 1 54.93 4.61 0.66 -2.20
Lpd 4 ∞ 6.36 3.18 -3.18
LM 7 ∞ 6.00 3.00 -3.00
LR 10 51.62 4.98 12.91 13.36

Single lens Data lens Start surface Focal length
1 1 34.33
2 2 -89.54
3 10 -15.99
4 12 15.16

Conditional expression (1) Numerical value
DR / f = 0.239

(Numeric data 4)
Unit mm

Surface data surface number rd nd νd Effective diameter
1 * 15.374 1.80 1.77250 49.5 8.67
2 36.729 1.50 8.31
3 ∞ 2.17 1.51633 64.1 10.00
4 ∞ 2.17 1.51633 64.1 10.00
5 ∞ 6.10 10.00
6 -6.939 0.80 1.80518 25.4 5.63
7 12.439 0.49 6.06
8 -369.575 1.80 1.80400 46.6 6.16
9 -13.063 0.10 6.86
10 33.366 2.30 1.85135 40.1 7.57
11 * -10.272 16.78 8.00
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 6.35832e-006 A 6 = 9.94547e-008 A 8 = 1.13327e-009

11th page
K = -7.87183e + 000 A 4 = -9.43651e-004 A 6 = 2.11563e-005 A 8 = -6.14038e-007 A10 = 7.07308e-009

Various data Zoom ratio 1.00

Focal length 20.80
F number 2.40
Half angle of view (degrees) 8.21
Statue height 3.00
Total lens length 36.00
BF 16.78

Entrance pupil position 0.00
Exit pupil position -358.32
Front principal point position 19.65
Rear principal point position -4.02

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
L1 1 33.02 1.80 -0.71 -1.68
Lpd 3 ∞ 4.33 1.43 -1.43
LR 6 21.09 5.49 8.49 8.98

Single lens Data lens Start surface Focal length
1 1 33.02
2 3 0.00
3 4 0.00
4 6 -5.43
5 8 16.80
6 10 9.45

Conditional expression (1) Numerical value
DR / f = 0.263

L0 optical system L1 first lens group having positive refractive power Lpd light splitting means LM reflecting member LR rear group

Claims (10)

A first lens unit having a positive refractive power;
A light splitting means for splitting the light flux from the first lens group into a plurality of light fluxes on a reflecting surface and reflecting them in different directions;
A rear group having a refractive power disposed in each optical path of the plurality of light beams,
The optical system according to claim 1, wherein the rear group includes a focus lens group that moves during focusing.   The optical system according to claim 1, wherein different object images are formed by a plurality of light beams divided by the light splitting unit. When the angle formed by the optical axis of the first lens group and the optical axis of the rear group is θ,
80 ° <θ <100 °
The optical system according to claim 1, wherein the following conditional expression is satisfied. When the distance on the optical axis between the object side vertex of the first lens group and the reflecting surface of the light splitting means is DR, and the focal length of the entire system is f,
0.1 <DR / f <0.5
The optical system according to claim 1, wherein the following conditional expression is satisfied.   5. The optical system according to claim 1, further comprising a reflecting member configured to reflect a light beam from the rear group in an object side direction.   6. A reflecting member is disposed in each of the optical paths of the plurality of light beams divided by the light splitting means, and the light beams reflected by the reflecting member are guided to the rear group. The optical system according to any one of the above.   The optical system according to claim 6, wherein an optical axis of the first lens group and an optical axis of the rear group are located in a plane orthogonal to each other.   With respect to a first plane formed by an optical axis of the first lens group and a first reflected optical axis when a light beam on the optical axis of the first lens group is reflected by the light splitting means, the first plane 7. The second plane formed by one reflected optical axis and a second reflected optical axis when a light beam of the first reflected optical axis is reflected by the reflecting member is orthogonal to claim 6. The optical system described.   An image pickup apparatus comprising: the optical system according to claim 1; and an image pickup element that receives an image formed by the optical system. An optical system, and an image sensor that receives an image formed by the optical system,
The optical system is
A first lens unit having a positive refractive power;
A light splitting means for splitting the light flux from the first lens group into a plurality of light fluxes on a reflecting surface and reflecting them in different directions;
A rear group having a refractive power disposed in each optical path of the plurality of light beams,
At the time of focusing, at least one of the lens group included in the rear group or the image sensor moves.