Stereo lens device and imaging device

Abstract

To excellently perform optical adjustment of a lens by using at least two adjustment members even when an optical axis interval between two optical systems arranged in parallel is narrow.SOLUTION: A stereo lens device includes: two optical systems 201R and 201L arranged in parallel; a holding member 234 which holds a lens 231b included in one of the two optical systems; and three fixing members 236 and 237 which are capable of fixing the holding member in a plane orthogonal to an optical axis of the lens and include at least two adjustment members 236 which are rotated around rotation center axes different from each other, to move the holding member in the plane. When viewed from an optical axis direction, a cross point P where the rotation center axes of at least two adjustment members cross with each other is located further away from the other of the two optical systems than the optical axis of the lens.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] The present invention relates to a lens device suitable for imaging a stereoscopic image (stereo image).

Background Art

[0002] A stereo lens device forms two object images having parallax with each other through two optical systems arranged in parallel so as to enable stereoscopic vision. Patent Document 1 discloses a stereo lens device in which the optical paths of two optical systems arranged in parallel are bent using a reflecting surface, and two object images can be formed on a single imaging element while securing an optical axis interval (baseline length) on the object side and narrowing the optical axis interval on the image side.

[0003] Further, Patent Document 2 discloses a stereo lens device having an adjustment mechanism (holding mechanism) for adjusting the eccentricity of the lenses on the image side of two optical systems by narrowing the optical axis interval on the image side compared to the object side and performing optical adjustments such as adjusting the eccentricity of the lenses on the image side of the two optical systems within the optical axis interval.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] When the optical axis interval on the image side of two optical systems is narrow as in the stereo lens devices of Patent Documents 1 and 2, it becomes difficult to arrange the adjustment mechanism for the lens on the image side. In the adjustment mechanism, eccentric rollers as three adjustment members arranged at intervals of 120° around the optical axis are usually used. However, in Patent Document No. 2, five eccentric rollers more than three are used, and these are not arranged at equal intervals of 120°.

[0006] The present invention provides a stereo lens device and an imaging device equipped therewith, which enable good optical adjustment of the lenses using at least two adjustment members, even when the distance between the optical axes of two parallel-arranged optical systems is narrow. [Means for solving the problem]

[0007] A stereo lens device, as one aspect of the present invention, comprises two parallel-arranged optical systems, a holding member for holding a lens included in one of the two optical systems, and three fixing members, each capable of fixing the holding member in a plane perpendicular to the optical axis of the lens, and including at least two adjustment members that can move the holding member in the plane by rotating around different rotational axes. The device is characterized in that, when viewed from the optical axis direction, the intersection point where the rotational axes of at least two adjustment members intersect is located further away from the other optical system than the optical axis of the lens. An imaging device equipped with the above stereo lens device also constitutes another aspect of the present invention. [Effects of the Invention]

[0008] According to the present invention, even if the distance between the optical axes of two parallel-arranged optical systems is narrow, the optical adjustment of the lens can be performed well using at least two adjustment members. [Brief explanation of the drawing]

[0009] [Figure 1] Cross-sectional view of the stereo lens device of the embodiment. [Figure 2] An exploded perspective view of the stereo lens device of the embodiment. [Figure 3] Another exploded perspective view of the stereo lens device of the embodiment. [Figure 4] A diagram showing the optical axis of the stereo lens device of the embodiment and the image circle on the image sensor. [Figure 5] A perspective view of the optical unit of the stereo lens device of the embodiment. [Figure 6] Rear view of the optical unit in the embodiment. [Figure 7]Top view of the optical unit in the embodiment. [Figure 8] Cross-sectional view of the optical unit in the embodiment. [Figure 9] Top view of the eccentric roller in the embodiment. [Figure 10] Perspective view of the eccentric roller in the embodiment. [Figure 11] Perspective view of the holding structure of the third lens group in the embodiment. [Figure 12] Another perspective view of the holding structure of the third lens group in the embodiment. [Figure 13] Cross-sectional view of the holding structure of the third lens group in the embodiment. [Figure 14] Diagram showing the movement locus of the optical axis of the rear lens in the embodiment. [Figure 15] Diagram showing the configuration of a camera equipped with the stereoscopic lens device of the embodiment. [Figure 16] Diagram showing the image circle in full-size and APS film-size imaging devices. [Figure 17] Diagram of the positional relationship of the rollers in the prior art.

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] FIG. 1 shows a cross-section of an imaging lens 200 as a stereoscopic lens device according to an embodiment of the present invention. FIG. 2 shows the imaging lens 200 disassembled as viewed from the object side (front side). FIG. 3 shows the imaging lens 200 disassembled as viewed from the image side (rear side). The imaging lens 200 is an interchangeable lens that can be attached to and detached (interchanged) with a lens interchangeable imaging device described later. However, the imaging lens 200 may be provided in a lens-integrated imaging device to constitute a stereoscopic imaging device.

[0012] The imaging lens 200 has a first optical system and a second optical system. In the present embodiment, one of the first and second optical systems is referred to as a right-eye optical system 201R, and the other is referred to as a left-eye optical system 201L.

[0013] The right optical system 201R and the left optical system 201L are arranged in parallel in the left-right direction (the vertical direction in FIG. 1). Note that the first optical system and the second optical system may be arranged in parallel in the vertical direction (the direction perpendicular to the plane of FIG. 1). In the following description, the components of the right optical system 201R are appended with R at the end of the reference numerals, and the components of the left optical system 201L are appended with L at the end of the reference numerals.

[0014] The right and left optical systems 201R and 201L each include a first lens group 211R, 211L, first and second prisms 220R / L, 230R / L, a second lens group 221R, 221L, and a third lens group 231R, 231L, which are arranged in order from the object side to the image side. Each lens group is composed of one or more lenses.

[0015] The first lens groups 211R, 211L, which are the portions on the object side of the first prisms 220R, 220L, each have a first optical axis OA1R, OA1L. As shown in FIG. 1, the first optical axes OA1R, OA1L are separated from each other by a distance (optical axis interval) L1. The distance L1 is referred to as the baseline length. The first lens groups 211R, 211L each have a convex front lens surface on the object side. As a result, the right and left optical systems 201R, 201L are full-angle fisheye optical systems that form a circular image.

[0016] The second lens groups 221R, 221L each have a second optical axis OA2R, OA2L that extends perpendicular to the first optical axes OA1R, OA1L in the left-right direction.

[0017] The third lens groups 231R, 231L, which are the portions on the image side of the second prisms 230R, 230L, each have a third optical axis OA3R, OA3L that is perpendicular to the second optical axes OA2R, OA2L and extends parallel to the first optical axes OA1R, OA1L. Each third lens group is composed of a front lens 231a and a rear lens 231b that are arranged in order from the object side to the image side.

[0018] The third optical axes OA3R and OA3L are separated from each other by a distance (optical axis spacing) L3 that is shorter than the baseline length L1 in the left-right direction. In the following explanation, the direction in which the first optical axis OA1(R,L) and the third optical axis OA3(R,L) extend (front-back direction) is called the optical axis direction. The direction perpendicular to the optical axis direction is called the radial direction, the direction perpendicular to the optical axis direction and the left-right direction is called the up-down direction, and the direction around the first and third optical axes OA1(R,L) and OA3(R,L) is called the circumferential direction.

[0019] The first prisms 220R and 220L, positioned between the first lens group 211R and 211L and the second lens group 221R and 221L, are reflective members (reflective surfaces) that bend the optical path of light passing through the first lens group 211R and 211L toward the second lens group 221R and 221L. Similarly, the second prisms 230R and 230L, positioned between the second lens group 221R and 221L and the third lens group 231R and 231L, are reflective members that bend the optical path of light passing through the second lens group 221R and 221L toward the third lens group 231R and 231L.

[0020] Thus, in this embodiment, the right eye optical system 201R and the left eye optical system 201L are bent optical systems that bend the optical path, but the right eye optical system and the left eye optical system may also be coaxial optical systems that extend the optical axis straight from the object side to the image side.

[0021] As shown in Figures 2 and 3, the right and left eye optical systems 201R and 201L are housed within the outer cover member 203 and secured to the lens top base 300 with screws. The lens top base 300 is secured to the lens bottom base 301, which is located within the outer cover member 203, with screws. The lens bottom base 301 is held in place by a linear guide (not shown) provided on the outer cover member 203, allowing it to move linearly in the optical axis direction while its rotation is restricted. As a result, the right and left eye optical systems 201R and 201L move together with the lens top base 300 and lens bottom base 301 (hereinafter also referred to as lens top / bottom bases 300 and 301) in the optical axis direction to adjust focus. A lens mount 202 is secured to the rear end of the outer cover member 203 with screws.

[0022] Furthermore, the front exterior member 204 is fixed to the front end of the exterior cover member 203 by screws or adhesive. The front exterior member 204 has two openings 204F that expose the first lenses 211R and 211L of the right and left eye optical systems 201R and 201L, respectively.

[0023] Here, we will describe the retention structure of the first lens group 211L of the left eye optical system 201L, but the retention structure of the first lens group 211R of the right eye optical system 201R is the same.

[0024] The first lens group 211L, the second lens group 221L, the third lens group 231L, the first prism 220L, and the second prism 230L are held together by a lens holding member 223L, along with the holding members that hold each lens group. A ring-shaped cover member 213 with an opening is attached to the outer circumference of the lens holding member 223L. The inner diameter of the opening of the cover member 213 is radially outward from the effective incident diameter of the first lens group 211L.

[0025] The lens holding member 212, which holds the first lens group 211L, is held by the front exterior member 204 and the exterior cover member 203 to which it is fixed, by the cover member 213 attached to its outer circumference being fitted into the opening 204F of the left front part 204B of the front exterior member 204.

[0026] Furthermore, the cover member 213 is attached to the lens holding member 212L so as not to be displaced in the optical axis direction. During assembly, the cover member 213 is assembled to the lens holding member 212L such that the groove portion of the cover member 213 (not shown) and the bayonet claw portion of the lens holding member 212L (not shown) are in different phases in the circumferential direction. After this, by rotating the cover member 213 in the circumferential direction, the bayonet claw portion enters the groove portion and engages with the groove portion in the optical axis direction. Alternatively, the cover member 213 may be provided with a bayonet claw portion and the lens holding member 212L may be provided with a groove portion.

[0027] In this manner, the outer circumferential surface of the cover member 213 attached to the lens holding member 212L is fitted to the inner circumferential surface of the opening 204F of the front exterior member 204 so as to be movable in the optical axis direction. As a result, the cover member 213 and the lens holding member 212L are held integrally with respect to the front exterior member 204 so as to be movable in the optical axis direction.

[0028] Instead of directly fitting the lens retaining member 212L into the opening 204F of the front exterior member 204, a cover member 213 that allows for play in the radial gap of the lens retaining member 212L is fitted into the opening 204F. This prevents the position of the lens retaining member 212L from being forcibly corrected even if its position is shifted in the left-right direction due to manufacturing errors. Therefore, it is possible to prevent the optical performance of the right and left eye optical systems 201R and 201L, as well as the relative error between the right and left eye optical systems 201R and 201L, from changing due to the assembly of the front exterior member 204.

[0029] Furthermore, a second sealing member 215 for drip-proofing and dustproofing is positioned between the bottom surface of the groove 213E provided on the outer circumference of the cover member 213 and the inner surface of the opening 204F of the front exterior member 204, in a state of radial compression.

[0030] Figure 4 shows the positional relationship between the first to third optical axes OA1R, OA1L to OA3R, and OA3L of the right and left eye optical systems 201R and 201L, the lens mount 202, and the image circles ICR and ICL on a single image sensor 111 provided in the imaging device, as viewed from the optical axis direction.

[0031] On the imaging surface of the image sensor 111, the image circle ICR of the right eye optical system 201R (hereinafter referred to as the right image circle) and the image circle ICL of the left eye optical system 201L (hereinafter referred to as the left image circle) are formed side by side in the left-right direction. The diameter ΦDIC of each image circle and the distance between the centers of the left and right image circles ICR and ICL are set so that the left and right image circles ICR and ICL do not overlap. For example, the imaging surface of the image sensor 111 may be divided into left and right halves, with the center of the right image circle ICR located at the center of the right imaging surface and the center of the left image circle ICL located at the center of the left imaging surface.

[0032] Here, we will explain why the configuration described later was adopted for the imaging lens of this embodiment. Imaging devices equipped with so-called twin-lens systems like this embodiment include those that use a 135 film size (full-frame) image sensor and those that use a smaller APS film size (APS size) image sensor. Figure 16 shows the image circles IC4R and IC4L formed by the full-frame image sensor F4 and its twin-lens system with dashed lines, and the image circles IC3R and IC3L formed by the APS-size image sensor F3 and its twin-lens system with solid lines.

[0033] When a full-frame twin-lens system is used with an APS-C size imaging system, the inner portion of image circles IC4R and IC4L is not vignetted, but the outer portion is. Therefore, for an APS-C size imaging system, the diameter of image circles IC3R and IC3L must be smaller than that of image circles IC4R and IC4L. Furthermore, the distance d3 between the centers OA3R and OA3L of image circles IC3R and IC3L must be narrower than the distance d4 between the centers OA4R and OA4L of image circles IC4R and IC4L.

[0034] To narrow the center distance d3 of the image circles IC3R and IC3L, the size of the adjustment parts (eccentric rollers, screws, springs, etc.) used for optical adjustments such as eccentricity adjustment of the lenses constituting each of the two optical systems of the imaging lens must be reduced by a factor proportional to the ratio of full-frame to APS-C size. However, this would compromise the strength of the adjustment parts and make assembly difficult.

[0035] Figure 17 shows the holding structure of the third lens group (rear lens) in one optical system, viewed from the optical axis direction, when designed using eccentric rollers of the same size as those used in a twin-lens reflex system for a full-frame camera. The rear lens is held by a 3-group holder 920, which is held by a 3-group base 910 via eccentric rollers 901A to 901E. In a normal holding structure, three eccentric rollers are arranged at 120° equal intervals around the optical axis, but in the holding structure of Figure 17, five eccentric rollers 901A to 901E are arranged at intervals different from 120° equal intervals. In this arrangement, the angle between the central axis of the upper eccentric roller 901A and the central axes of the lower eccentric rollers 901D and 901E in the figure is close to 180°. In this configuration, while the movement of the 3-group holder 920 is restricted in the left-right direction in the figure during eccentricity adjustment, the restriction on movement in the up-down direction is weaker, making the 3-group holder 920 prone to looseness. As a result, it becomes difficult to perform proper eccentricity adjustment.

[0036] Figures 5 to 8 show the optical unit of this embodiment in which the right and left eye optical systems (first lens group 211R, 211L to third lens group 231R, 231L) of the imaging lens 200 are held by lens holding members 212R and 212L. Figure 5 shows the optical unit viewed from an oblique angle on the image side, and Figure 6 shows the optical unit viewed from the image side. Here, as shown in Figure 6, the entire optical unit viewed from the image side is divided into a right eye region 20R and a left eye region 20L on the Z plane.

[0037] Figure 7 shows the optical unit viewed from above. Figure 8 shows the holding mechanism of the third lens group viewed from the image side (lens mount side), and shows a cross-section passing through the rotational center axis of the eccentric roller (cross-section when cut along the DD line in Figure 7). This cross-section is a plane perpendicular to the third optical axes OA3R and OA3L. Furthermore, Figure 9 shows the eccentric roller 236 as an adjustment member viewed from the direction of its rotational center axis, and Figure 10 shows the eccentric roller 236 viewed from an oblique angle. The eccentric roller 236 and the coaxial roller, which will be described later, correspond to fixing members that can fix the 3-group holder 234 shown in Figure 8 within the cross-section of Figure 8.

[0038] As shown in Figures 9 and 10, a screw hole 236c is formed on the inside of the eccentric roller 236 into which a roller mounting screw is inserted. The eccentric roller 236 is attached to the 3-group holder 234 by tightening the roller mounting screw inserted into the screw hole 236c into the 3-group holder 234.

[0039] As shown in Figure 10, the eccentric roller 236 has a small-diameter portion 236b with a smaller outer diameter and a large-diameter portion 236a with a larger outer diameter. The small-diameter portion 236b is formed coaxially with the inner screw hole 236c, while the large-diameter portion 236a is formed with its central axis offset from the small-diameter portion 236b and the screw hole 236c (i.e., it is eccentric).

[0040] Furthermore, as shown in Figures 9 and 10, a slot (notch) 236d is formed at the upper end of the large-diameter portion 236a. The slot 236d is the part into which a tool such as a flathead screwdriver engages, and by rotating the tool, the eccentric roller 236 can be rotated around its rotational axis (the central axis between the small-diameter portion 236b and the screw hole 236c). On the other hand, the coaxial roller 237 shown in Figure 8 is formed entirely coaxially and does not require rotation with a tool, so no slot is formed therein.

[0041] Figures 11 and 12 show the holding mechanism for the third lens group 231L. Figure 11 shows the holding mechanism viewed from an oblique direction, and Figure 12 shows the holding mechanism viewed from another oblique direction. Figure 13 shows a cross-section of the holding mechanism from the image side in the direction of the optical axis, passing through the rotational center axis of the eccentric roller (a plane perpendicular to the third optical axis OA3L). Note that a holding mechanism is provided for both the third lens group 231R and 231L, and both holding mechanisms have the same configuration except that their arrangement phases around the third optical axes OA3R and OA3L are different (they are rotationally symmetric with respect to the central axis of the lens mount 202). For this reason, Figures 11, 12, and 13 show only the holding mechanism for the third lens group 231L.

[0042] As mentioned above, the third lens groups 231R and 231L are each composed of a front lens 231a and a rear lens 231b. In each of the third lens groups 231R and 231L, the front lens 231a is held by the third lens group base 233 by heat-sealing its entire outer circumference to the base 233. As shown in Figures 11 and 12, the third lens group base 233 has a wall portion 233d in the shape of a cylinder with a D-cut portion in the circumferential direction. The third lens groups 231R and 231L are each fixed to the lens holding members 223R and 223L by screws 239.

[0043] The rear lens 231b is held by the 3-group holder 234 by heat crimping to a crimping portion provided on the 3-group holder 234. The left and right 3-group bases 233 are arranged so that the D-cut portions of the wall portion 233d are adjacent to each other. Parts of the outer periphery of the left and right 3-group holders 234 are adjacent to each other in the D-cut (where the wall portion 233d is absent) region of the wall portion 233d of the 3-group base 233. The left and right holding mechanisms formed and arranged in this way can be made smaller in the radial direction in the parts where they are adjacent to each other than in other parts (parts where the wall portion 233d is provided). A roller seat, which will be described later, is provided on the 3-group holder 234.

[0044] As shown in Figures 11 and 12, the wall portion 233d of the three-group base 233 has a first hole 233a, a second hole 233b, and a third hole 233c formed therein. These first to third holes 233a to 233c are arranged at equal intervals of 120° in the circumferential direction of the wall portion 233d. The central axes of the first to third holes 233a to 233c intersect at a point P that passes through the central axis of the arc along the wall portion 233d, as shown in Figure 13.

[0045] Furthermore, in Figure 13, the center of the rear lens 231b, which holds the 3-group holder 234 (rear lens 231b) in the 3-group base 233, lies on the third optical axis OA3L, which is located closer to the D-cut portion or the Z-plane (in the case of the rear lens 231b in Figure 13 being the 3rd lens group 231L of the left eye optical system, this corresponds to the 3rd lens group 231R of the right eye optical system 201R) than point P. In other words, point P, where the central axes of the first to third holes 233a to 233c intersect each other, is located further from the 3rd lens group 231R than the lens optical axis of the rear lens 231b (3rd lens group 231L of the left eye optical system).

[0046] The same eccentric roller 236 is inserted into the first hole 233a and the second hole 233b, but the eccentric rollers inserted into each hole are designated as eccentric roller 236A and 236B, respectively. The outer diameter portion 236a of the eccentric roller 236A and 236B are fitted to the inner circumferential surfaces of the first hole 233a and the second hole 233b, respectively. The same eccentric roller 236C or coaxial roller 237 as the eccentric rollers 236A and 236B is inserted into the third hole 233c, and the large diameter portion 236a of the eccentric roller 236C or the outer circumferential surface of the coaxial roller 237 is fitted to the inner circumferential surface of the third hole 233c.

[0047] The eccentric rollers 236A, 236B, and eccentric roller 236C, or the coaxial roller 237, are inserted into the first roller seats 234a, the second roller seat 234b, and the third roller seat 234c, respectively, which are provided at three circumferential locations on the outer circumference of the three-group holder 234 at 120° intervals. The small diameter portion 236b of each eccentric roller or the small diameter portion (not shown) of the outer circumference of the coaxial roller 237 fits into the inner circumference of each roller seat. Each roller is then rotatably mounted to the three-group holder 234 by screws.

[0048] As shown in Figure 13, the first Colossus 234a and the second Colossus 234b are positioned so as to be vertically symmetrical with respect to a line (plane) passing through point P and a point on the third optical axis OA3L in the figure. The central axes of the first Colossus 234a, the second Colossus 234b, and the third Colossus 234c intersect at point P. That is, point P, where the central axes of the first to third Colossus 234a to 234c intersect, is located further from the third lens group 231R than the lens optical axis of the rear lens 231b (third lens group 231L), similar to the intersection of the central axes of the first to third holes 233a to 233c of the 3-group base 233. In other words, the rotational axes of the eccentric rollers 236A, 236B and eccentric roller 236C or coaxial roller 237 inserted into the first to third Corolla constellations 234a to 234c also intersect each other at a point P (hereinafter referred to as the roller axis intersection) that is further away from the third lens group 231R than the lens optical axis of the rear lens 231b.

[0049] Although the central axes of the first and second Colossi constellations 234a and 234b are offset from the third optical axis OA3L, these two constellations are located closer to the rear lens 231b than the third Colossi constellation 234c. The central axis of the third Colossi constellation 234c intersects the third optical axis OA3L.

[0050] Furthermore, the rotational axes of the eccentric rollers 236A, 236B, and eccentric roller 236C or coaxial roller 237 do not necessarily all lie in the same cross-section perpendicular to the third optical axis OA3L. That is, these rotational axes may lie in different cross-sections perpendicular to the third optical axis OA3L but at different positions in the optical axis direction. Even in this case, if these rotational axes intersect each other when viewed from the optical axis direction, that intersection is the roller axis intersection P.

[0051] Furthermore, the first to third Colossi 234a-234c (eccentric colossi 236A-236C or coaxial colossi 237) do not necessarily have to be arranged at exactly 120° intervals, and may be positioned slightly (for example, within 10°) from the exact 120° intervals. In other words, they only need to be arranged at intervals based on (or equivalent to) 120° intervals. Also, the central axes of the first to third Colossi 234a-234c do not necessarily have to intersect at a single point. If the intersection of the central axes of the first and second Colossi 234a and 234b is offset from the third optical axis OA3L, and the intersection of the central axes of 234a and 234b is further from the Z-plane or OA3R than the third optical axis OA3L, then the central axis of the third Colossi 234c does not need to intersect with the optical axis OA3L.

[0052] The optical adjustment mechanism for the rear lens 231b is comprised of a three-group holder 234 having first to third roller positions 234a to 234c, a three-group base 233 having first to third hole portions 233a to 233c, and eccentric rollers 236A, 236B, 236C (or coaxial roller 237).

[0053] In the first hole 233a, the large-diameter portion (eccentric portion) 236a of the eccentric roller 236A fits circumferentially to the wall portion 233d, but does not fit in the direction in which the third optical axis OA3L extends. In the second hole 233b, the large-diameter portion 236a of the eccentric roller 236B fits circumferentially to the wall portion 233d, but does not fit in the direction in which the third optical axis OA3R extends. In the third hole 233c, the large-diameter portion 236a of the eccentric roller 236C or the coaxial roller 237 fits circumferentially to the wall portion 233d, but does not fit in the direction in which the third optical axis OA3R extends. By rotating the first eccentric roller 236A and the second eccentric roller 236B (and furthermore, the third eccentric roller 236C) around their respective rotational axes, the 3-group holder 234 can be moved in a plane perpendicular to the third optical axis OA3L, thereby adjusting the eccentricity of the rear lens 231b relative to the front lens 231a.

[0054] Three tension springs 238 are provided to generate a biasing force to prevent displacement of the rear lens 231b in the optical axis direction and circumferential direction caused by the fitting play in each hole of the eccentric rollers described above. The tension springs 238 are hung at an angle with respect to the optical axis direction between a hook 234e provided on the 3-group holder 234 shown in Figure 11 and a hook 233e provided on the 3-group base 233. As a result, the tension springs 238 bias the 3-group holder 234 relative to the 3-group base 233 in one direction in the circumferential direction and also bias them toward each other in the optical axis direction.

[0055] As shown in Figure 13, one tension spring 238 and the hook 233e attached to it, located in the part of the left (third lens group 231L) retaining mechanism adjacent to the right (third lens group 231R) retaining mechanism, are positioned in the right eye region 20R, beyond the Z-plane. Similarly, one tension spring 238 and the hook 233e located in the part of the right retaining mechanism adjacent to the left retaining mechanism, are positioned in the left eye region 20L, beyond the Z-plane. To enable this arrangement, as shown in Figures 11 and 13, recesses 233f are provided in each of the left and right retaining mechanisms (3-group base 233). The recess 233f of one retaining mechanism forms a space for the tension spring 238 and hook 233e, which are part of the other retaining mechanism, to be positioned; in other words, it is provided to avoid interference between the tension spring 238 and hook 233e and the other retaining mechanism.

[0056] The left and right three-group bases 233, which each hold the third lens groups 231R and 231L, are fixed to the lens holding members 223R and 223L, and the lens holding members 223R and 223L are further fixed to the lens top base 300, thereby integrating the left and right holding mechanisms. As shown in Figures 11 to 13, eccentric rollers are not provided on the Z-plane side surfaces of the left and right holding mechanisms, and eccentric rollers 236A, 236B and eccentric roller 236C or coaxial roller 237 are arranged on the parts other than the Z-plane side surfaces. Therefore, with the left and right holding mechanisms integrated, all eccentric rollers can be accessed from the radially outside of each holding mechanism, and the optical adjustment of the rear lens 231b can be performed by rotating each eccentric roller. Furthermore, since the roller mounting screw inserted on the inner circumference side of the eccentric roller 236C is also accessible, the eccentric roller 236C and coaxial roller 237 can be easily replaced.

[0057] Next, the optical adjustment (eccentricity adjustment) of the rear lens 231b will be explained using Figures 13 and 14. Here, we will explain the case where three eccentricity rollers 236A, 236B, and 236C are provided in the holding mechanism on the left. Figure 14 shows a magnified view of the area around the optical axis OA3L of the third lens group 231R in Figure 13, and shows the movement trajectory of the lens optical axis of the rear lens 231b due to eccentricity adjustment.

[0058] In Figure 13, let A, B, and C be the points where the three straight lines perpendicular to the rotational axes of the three eccentric rollers 236A to 236C intersect. Points A, B, and C are the vertices of the triangle shown in the figure.

[0059] When one of the three eccentric rollers 236A to 236C is rotated, the 3-group holder 234 and the rear lens 231b fixed thereto rotate around the corresponding points A, B, or C from the position where the three eccentric rollers 236A to 236C are fitted and in contact with the 3-group base 233. For example, when eccentric roller 236A is rotated, the optical axis of the rear lens 231b rotates around point A, as shown by the dashed-dotted arc in Figure 13. When eccentric rollers 236B and 236C are rotated, the optical axes of the rear lens 231b rotate around points B and C, respectively. This is because the two eccentric rollers other than the rotating eccentric roller are fitted circumferentially to the 3-group base 233, and the 3-group holder 234 can only move in the direction of the rotational axis of each eccentric roller. Therefore, the 3-group holder 234 moves in a circular arc trajectory tangent to the rotational axes of the two non-rotating eccentric rollers. In this way, the optical axis of the rear lens 231b rotates and moves in a circular arc trajectory centered on point A, B, or C by rotating each eccentric roller.

[0060] In the case of a typical monocular lens, the lens optical axis of the lens to be adjusted is aligned with the intersection point where the rotational axes of multiple eccentric rollers intersect each other. In contrast, in this embodiment, the roller axis intersection P where the rotational axes of at least two eccentric rollers 236A, 236B (and an additional eccentric roller 236C) intersect each other is located further from the Z-plane and the right eye optical system 201R than the lens optical axis of the rear lens 231b (third optical axis OA3L).

[0061] In a monocular lens, if the amount of eccentricity of each eccentric roller is the same, rotating any of the eccentric rollers will move the lens optical axis of the target lens by the same amount relative to the third optical axis OA3L. In contrast, in this embodiment, although the angle at which the lens optical axis of the rear lens 231b rotates around point A, B, or C is the same at 37 min as shown in Figure 13, the amount by which the lens optical axis of the rear lens 231b moves relative to the third optical axis OA3L differs depending on the eccentric roller being rotated. This is because the radius of the arc trajectory of the lens optical axis of the rear lens 231b becomes smaller when rotating around point C, and the radius of the arc trajectory of the lens optical axis of the rear lens 231b becomes larger when rotating around points A and B.

[0062] In Figure 14, the rotation of the eccentric roller 236A causes the optical axis of the rear lens 231b to move along a circular arc from +Vα to -Vα with point A as the center. The rotation of the eccentric roller 236B causes the optical axis of the rear lens 231b to move along a circular arc from +Vβ to -Vβ with point B as the center. The rotation of the eccentric roller 236C causes the optical axis of the rear lens 231b to move along a circular arc from +Vγ to -Vγ with point C as the center. The three points A to C are the vertices of an equilateral triangle because the three eccentric rollers 236A to 236C are arranged at equal intervals of 120° around the roller axis intersection P. Therefore, if the eccentricity of the three eccentric rollers 236A to 236C is the same, the angle at which the optical axis of the rear lens 231b moves along the circular arc will be the same at 37 minutes, as shown in Figure 13. However, as mentioned earlier, the radius of the arc trajectory passing through ±Vγ is smaller than the radii of the other arc trajectories, so when the eccentric roller 236C is rotated, the amount of movement of the lens optical axis of the rear lens 231b is smaller than when the eccentric rollers 236A and 236B are rotated. Since points A and B are in vertically symmetrical positions as shown in Figure 13, the amount of movement of the lens optical axis of the rear lens 231b when the eccentric rollers 236A and 236B are rotated is the same for both of them.

[0063] Furthermore, since the roller axis intersection P is located inside the circular arc trajectory passing through the third optical axis OA3L with points A and B as the center, the radius of the circular arc trajectory is larger compared to when the roller axis intersection is located on the third optical axis OA3L, as in a normal monocular lens. For this reason, the amount of movement of the lens optical axis of the rear lens 231b with points A and B as the center is larger than when the roller axis intersection is located on the third optical axis OA3L.

[0064] By combining these three circular arc trajectories, the optical axis of the rear lens 231b can move within the roughly hexagonal region AREA(Vα,Vβ,Vγ) shown by the dashed line in Figure 14. Since each circular arc trajectory is only a small part of the entire circle it contains, it can be approximated as a straight line.

[0065] In this embodiment, the eccentric roller 236C can be replaced with a coaxial roller 237, which has zero eccentricity. When using the coaxial roller 237, the optical axis of the rear lens 231b can move within the roughly diamond-shaped region AREA(Vα,Vβ) shown by the dashed line in the figure. The radius of the circle shown by the dashed line inscribed in region AREA(Vα,Vβ) should be set to match the required amount of eccentricity adjustment of the optical axis of the rear lens 231b.

[0066] Replacing the eccentric roller 236C with the coaxial roller 237 and not using it for eccentricity adjustment reduces the amount of movement that can be made to the optical axis of the rear lens 231b. However, in this case, the amount of movement of the optical axis of the rear lens 231b is the same for the amount of rotation of the eccentric rollers 236A and 236B, so the adjuster can rotate the eccentric rollers 236A and 236B simultaneously with both hands, making the adjustment work easier.

[0067] In contrast, when using the same eccentric rollers 236A to 236C as three eccentric rollers, the amount of movement that can be made to the optical axis of the rear lens 231b can be increased compared to when using the coaxial roller 237. Moreover, the amount of movement of the optical axis of the rear lens 231b in relation to the amount of rotation of the eccentric roller 236C is smaller than the amount of movement of the optical axis of the lens in relation to the same amount of rotation of the eccentric rollers 236A and 236B. Therefore, it is possible to perform adjustment work by rotating the eccentric rollers 236A and 236B to make rough adjustments to the optical axis of the rear lens 231b mainly in the horizontal direction, and then rotating the eccentric roller 236C to make fine adjustments mainly in the vertical direction. It is also possible to perform adjustment work by first using the coaxial roller 237 to rotate the eccentric rollers 236A and 236B to adjust the eccentricity of the optical axis of the rear lens 231b, and then, if the amount of adjustment is insufficient, replacing the coaxial roller 237 with the eccentric roller 236C and readjusting.

[0068] The adjustment work is performed with the optical unit in the state shown in Figure 5. After adjusting the positions of the left and right rear lenses 231b in the optical unit to the eccentric position that yields the best optical performance, the 3-group holder 234 is bonded and fixed to the 3-group base 233. At this time, as shown in Figure 11, adhesive is filled into the gap between the hole 234d formed in the 3-group holder 234 and the protrusion 233g of the 3-group base 233 that is inserted therein. After this bonding, in order to improve the appearance and prevent the intrusion of dust and water droplets, a dustproof and waterproof 3-group sheet 235 is attached and fixed to each of the left and right 3-group bases 233, as shown in Figures 6 and 7.

[0069] According to this embodiment, the left and right third lens groups 231R and 231L can be brought close to each other and housed within the lens mount 202. Furthermore, since the optically adjustable holding mechanisms for each of the third lens groups 231R and 231L are constructed using the same parts and arranged rotationally symmetrically with respect to the central axis of the lens mount 202 (the axis between the third lens groups 231R and 231L), the manufacturing of the imaging lens 200 can be simplified.

[0070] Figure 15 shows a stereo imaging system 100 configured by attaching the imaging lens 200 of this embodiment to a digital camera (hereinafter simply referred to as "camera") 110 as an interchangeable lens imaging device. The imaging lens 200 has a lens control unit 209 in addition to the right eye and left eye optical systems 201R and 201L.

[0071] The camera 110 includes an image sensor 111, an A / D converter 112, an image processing unit 113, a display unit 114, an operation unit 115, a storage unit 116, a camera control unit 117, and a camera mount 122. When the lens mount 202 of the imaging lens 200 is attached to the camera mount 122 of the camera 110, the camera control unit 117 and the lens control unit 209 are electrically connected and communication begins.

[0072] The image sensor 111 is a single photoelectric conversion element, such as a CCD sensor or CMOS sensor, that generates analog electrical signals by photoelectric conversion (imaging) the right eye image (ICR) and left eye image (ICL), which are optical images formed by the right eye and left eye optical systems 201R and 201L, respectively. The A / D converter 112 converts the analog electrical signals output from the image sensor 111 into digital signals. The image processing unit 113 performs various image processing on the digital signals output from the A / D converter 112 to generate image data. The A / D converter 112 and the image processing unit 113 may be built into the image sensor 111. The display unit 114 has a display element such as a liquid crystal panel and displays images and various information corresponding to the image data.

[0073] The operation unit 115 functions as an interface for the user to input various instructions. If the display unit 114 is equipped with a touch sensor, this touch sensor is also included in the operation unit 115. The storage unit 116 consists of RAM, ROM, SSD, etc., and stores image data generated by the image processing unit 113, as well as programs and various data used by the camera control unit 117, which acts as a computer.

[0074] The camera control unit 117 is composed of a CPU and the like, and controls the operation of the camera 110, as well as the operation of the imaging lens 200 through communication with the lens control unit 209.

[0075] By using the imaging lens 200 of this embodiment, the camera 110 can generate stereo images (right-eye image and left-eye image) that have parallax between them and can be viewed in 3D through imaging. The stereo images are viewed in 3D by an observer through an image display device such as VR goggles.

[0076] The above embodiments include the following configuration.

[0077] (Composition 1) Two optical systems arranged in parallel, A holding member for holding a lens included in one of the two optical systems, The holding member is fixed in a plane perpendicular to the optical axis of the lens, and the fixing member includes at least two adjustment members that are rotated around different rotational axes, thereby moving the holding member in the plane. A stereo lens device characterized in that, when viewed from the optical axis direction, the intersection point where the rotational centers of the at least two adjusting members intersect each other is located further away from the other optical system of the two optical systems than the optical axis of the lens. (Configuration 2) The stereo lens device according to configuration 1, characterized in that the three fixing members are arranged at intervals based on a 120° interval in the circumferential direction centered on the intersection. (Composition 3) The stereo lens device according to configuration 1 or 2, characterized in that the adjustment member is an eccentric roller. (Composition 4) All three of the aforementioned fixing members are the eccentric rollers. The stereo lens device according to configuration 3, characterized in that the two eccentric rollers are positioned closer to the optical axis of the lens than one of the eccentric rollers. (Composition 5) The stereo lens apparatus according to configuration 4, characterized in that the amount of movement of the holding member for the same amount of rotation is different when the two eccentric rollers are rotated compared to when the one eccentric roller is rotated. (Composition 6) Of the three fixing members, two are the eccentric rollers and one is the coaxial roller. The stereo lens device according to configuration 3, characterized in that the two eccentric rollers are positioned closer to the optical axis of the lens than the coaxial roller. (Composition 7) The holding member and the three fixing members are provided for each of the two optical systems. A stereo lens device according to any one of configurations 1 to 6, characterized in that the three fixing members provided for each of the two optical systems are arranged rotationally symmetrically with respect to the axis between the two optical systems. (Composition 8) Each of the two optical systems includes a reflective surface, and the optical axis spacing of the part of the two optical systems closer to the image is narrower than the optical axis spacing of the part closer to the object than the reflective surface. The stereo lens device according to any one of configurations 1 to 7, characterized in that the lens is included in the image-side portion. (Composition 9) A stereo lens device as described in any one of configurations 1 to 8, An imaging device characterized by having a single image sensor that captures the two optical images formed by the two optical systems of the stereo lens device.

[0078] (Other examples) The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0079] The embodiments described above are merely representative examples, and various modifications and changes can be made to each embodiment when implementing the present invention. [Explanation of Symbols]

[0080] 200 Stereo Imaging Lens 201R Right eye optical system 201L Left eye optical system 211R, 211L First lens group 221R, 221L Second lens group 231R, 231L Third lens group 231a Front lens (third lens group) 231b Rear lens (third lens group) 233 Group 3 base 234 3-group holder 236, 236A, 236B, 236C Eccentric roller 237 Coaxial roller 238 Tension spring OA3L 3rd optical axis P intersection

Claims

1. Two optical systems arranged in parallel, A holding member for holding a lens included in one of the two optical systems, The holding member comprises three members capable of fixing the holding member in a plane perpendicular to the optical axis of the lens, and the fixing members include at least two adjustment members that can move the holding member in the plane by rotating around different rotational axes. A stereo lens device characterized in that, when viewed from the optical axis direction, the intersection point where the rotational axes of the at least two adjusting members intersect each other is located further away from the other optical system of the two optical systems than the optical axis of the lens.

2. The stereo lens device according to claim 1, characterized in that the three fixing members are arranged at intervals based on a 120° interval in the circumferential direction centered on the intersection.

3. The stereo lens device according to claim 1, characterized in that the adjustment member is an eccentric roller.

4. All three of the aforementioned fixing members are the eccentric rollers. The stereo lens device according to claim 3, characterized in that the two eccentric rollers are positioned closer to the optical axis of the lens than one of the eccentric rollers.

5. The stereo lens apparatus according to claim 4, characterized in that the amount of movement of the holding member for the same amount of rotation is different when the two eccentric rollers are rotated compared to when the one eccentric roller is rotated.

6. Of the three fixing members, two are the eccentric rollers and one is the coaxial roller. The stereo lens device according to claim 3, characterized in that the two eccentric rollers are positioned closer to the optical axis of the lens than the coaxial roller.

7. The holding member and the three fixing members are provided for each of the two optical systems. The stereo lens device according to claim 1, characterized in that the three fixing members provided for each of the two optical systems are arranged rotationally symmetrically with respect to the axis between the two optical systems.

8. Each of the two optical systems includes a reflective surface, and the optical axis spacing of the part of the two optical systems closer to the image is narrower than the optical axis spacing of the part closer to the object than the reflective surface. The stereo lens device according to claim 1, characterized in that the lens is included in the image-side portion.

9. A stereo lens device according to any one of claims 1 to 8, An imaging device characterized by having a single image sensor that captures the two optical images formed by the two optical systems of the stereo lens device.

Images