Stereo lens device and imaging apparatus

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 capturing images that can be viewed stereoscopically (stereo images). [Background technology]

[0002] A stereo lens device forms two object images that can be viewed stereoscopically with parallax between them through two parallel-arranged optical systems. Patent Document 1 discloses a stereo lens device that bends the optical paths of the two parallel-arranged optical systems using a reflecting surface, thereby ensuring the distance between the optical axes (baseline length) on the object side while narrowing the distance between the optical axes on the image side, thereby enabling two object images to be formed on a single imaging element.

[0003] Patent Document 2 also discloses a stereo lens device having an adjustment mechanism (holding mechanism) for narrowing the optical axis spacing on the image side compared to the object side and performing optical adjustments such as decentering adjustment of the image-side lenses of two optical systems within the optical axis spacing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-008629 [Patent Document 2] Japanese Patent Publication No. 2023-050330 Summary of the Invention [Problem to be solved by the invention]

[0005] When the optical axis spacing on the image side of the two optical systems is narrow, as in the stereo lens devices of Patent Documents 1 and 2, it becomes difficult to arrange an adjustment mechanism for the image-side lens. The adjustment mechanism typically uses three eccentric rollers as adjustment members arranged at 120° intervals around the optical axis. However, Patent Document 2 uses five eccentric rollers, which are more than three, and are not arranged at equal 120° intervals.

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

[0007] One aspect of the present invention provides a stereo lens device comprising two parallel-arranged optical systems, a holding member for holding a lens included in one of the two optical systems, and three fixing members capable of fixing the holding member in a plane perpendicular to the optical axis of the lens, the fixing members including at least two adjusting members that can be rotated about different rotational central axes to move the holding member in the plane. When viewed from the optical axis direction, the intersection of the rotational central axes of the at least two adjusting members is located farther from the other of the two optical systems than the optical axis of the lens. An imaging device equipped with the 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 optical systems arranged in parallel is narrow, optical adjustment of the lenses can be performed satisfactorily using at least two adjustment members. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of a stereo lens device according to an embodiment. [Figure 2] FIG. 1 is an exploded perspective view of a stereo lens device according to an embodiment. [Figure 3] FIG. 2 is another exploded perspective view of the stereo lens device according to the embodiment. [Figure 4] 3A and 3B are diagrams showing optical axes of the stereo lens device and an image circle on an imaging element according to the embodiment; [Figure 5] FIG. 2 is a perspective view of an optical unit of the stereo lens device according to the embodiment. [Figure 6] FIG. 4 is a rear view of the optical unit in the embodiment. [Figure 7]FIG. 2 is a top view of an optical unit in the embodiment. [Figure 8] FIG. 3 is a cross-sectional view of an optical unit in the embodiment. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] FIG. 10 is a perspective view of a holding structure for a third lens group in the embodiment. [Figure 12] FIG. 10 is another perspective view of the holding structure for the third lens group in the embodiment. [Figure 13] FIG. 4 is a cross-sectional view of a holding structure for a third lens group in the embodiment. [Figure 14] FIG. 10 is a diagram showing the movement locus of the optical axis of the rear lens in the embodiment. [Figure 15] FIG. 1 is a diagram showing the configuration of a camera equipped with a stereo lens device according to an embodiment. [Figure 16] A diagram showing the image circles of full-size and APS film size imaging devices. [Figure 17] FIG. 10 is a diagram showing the positional relationship of rollers in the prior art. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment 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 stereo lens device according to an embodiment of the present invention. Fig. 2 shows an exploded view of the imaging lens 200 as seen from the object side (front side). Fig. 3 shows an exploded view of the imaging lens 200 as seen from the image side (rear side). The imaging lens 200 is an interchangeable lens that can be attached to (removed from) an interchangeable lens imaging device, which will be described later. However, a stereo imaging device may also be configured by providing the imaging lens 200 in a lens-integrated imaging device.

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

[0013] The right-eye optical system 201R and the left-eye optical system 201L are arranged in parallel in the left-right direction (the vertical direction in FIG. 1). The first optical system and the second optical system may also be arranged in parallel in the vertical direction (the direction perpendicular to the paper surface of FIG. 1). In the following description, the components of the right-eye optical system 201R are designated by symbols suffixed with R, and the components of the left-eye optical system 201L are designated by symbols suffixed with L.

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

[0015] The first lens groups 211R and 211L, which are located closer to the object than the first prisms 220R and 220L, have first optical axes OA1R and OA1L, respectively. As shown in FIG. 1, the first optical axes OA1R and OA1L are spaced apart by a distance (optical axis separation) L1. The distance L1 is referred to as the base length. The first lens groups 211R and 211L each have a front lens surface that is convex toward the object side. This makes the right-eye and left-eye optical systems 201R and 201L all-around fisheye optical systems that form circular images.

[0016] The second lens groups 221R and 221L have second optical axes OA2R and OA2L that extend perpendicularly to the first optical axes OA1R and OA1L in the left-right direction, respectively.

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

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

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

[0020] As described above, the right eye optical system 201R and the left eye optical system 201L in this embodiment are each bending optical systems that bend the optical path, but the right eye optical system and the left eye optical system may each be coaxial optical systems whose optical axes extend straight from the object side to the image side.

[0021] As shown in FIGS. 2 and 3, the right-eye and left-eye optical systems 201R and 201L are housed in an exterior cover member 203 and fixed to a lens top base 300 with screws. The lens top base 300 is fixed to a lens bottom base 301 arranged in the exterior cover member 203 with screws. The lens bottom base 301 is held so as to be able to move linearly in the optical axis direction while its rotation is restricted by a linear guide portion (not shown) provided in the exterior cover member 203. This allows the right-eye and left-eye optical systems 201R and 201L to move integrally in the optical axis direction together with the lens top base 300 and the lens bottom base 301 (hereinafter also referred to as lens top / bottom bases 300 and 301) to perform focus adjustment. A lens mount 202 is fixed to the rear end of the exterior cover member 203 with screws.

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

[0023] Here, the holding structure of the first lens group 211L of the left-eye optical system 201L will be described, but the holding 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 by a lens holding member 223L together with holding members that hold each lens group. A ring-shaped cover member 213 having an opening is attached to the outer periphery of the lens holding member 223L. The inner diameter of the opening of the cover member 213 is radially outward of the effective entrance diameter of the first lens group 211L.

[0025] The lens holding member 212 holding the first lens group 211L is held by the front exterior member 204 and further by the exterior cover member 203 to which it is fixed, by fitting the cover member 213 attached to its outer periphery into the opening 204F on the left front surface 204B of the front exterior member 204.

[0026] Furthermore, the cover member 213 is attached so as not to be displaced in the optical axis direction relative to the lens holding member 212L. During assembly, the cover member 213 is attached to the lens holding member 212L so that the grooves of the cover member 213 (not shown) and the bayonet claws of the lens holding member 212L (not shown) are in different phases in the circumferential direction. Thereafter, by rotating the cover member 213 in the circumferential direction, the bayonet claws enter the grooves and engage with them in the optical axis direction. Note that the cover member 213 may be provided with bayonet claws, and the lens holding member 212L may be provided with grooves.

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

[0028] Rather than directly fitting the lens holding 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 holding member 212L is fitted into the opening 204F. As a result, even if the position of the lens holding member 212L in the left-right direction is shifted due to manufacturing errors, the position is not forcibly corrected. Therefore, it is possible to prevent the optical performance of the right-eye and left-eye optical systems 201R, 201L and the relative error between the right-eye and left-eye optical systems 201R, 201L from changing due to the assembly of the front exterior member 204.

[0029] Furthermore, a second sealing member 215 for preventing drips and dusts is arranged between the bottom surface of groove portion 213E provided on the outer periphery of cover member 213 and the inner circumferential surface of opening 204F of front exterior member 204 so as to be sandwiched in a radially compressed state.

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

[0031] An image circle ICR of the right-eye optical system 201R (hereinafter referred to as the right image circle) and an 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 on the imaging surface of the image sensor 111. The diameter ΦDIC of each image circle and the center-to-center distance between 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, and the center of the right image circle ICR may be positioned at the center of the right imaging surface, and the center of the left image circle ICL may be positioned at the center of the left imaging surface.

[0032] Here, we will explain the reason why the configuration described below is adopted in the imaging lens of this embodiment. Imaging devices equipped with so-called twin lenses like this embodiment include those that use an image sensor with a 135 film size (full size) and those that use an image sensor with an APS film size (APS size) that is smaller than full size. In Figure 16, the image circles IC4R and IC4L formed by the full-size image sensor F4 and the twin lenses for it are shown with dashed lines, and the image circles IC3R and IC3L formed by the APS-size image sensor F3 and the twin lenses for it are shown with solid lines.

[0033] When a full-frame twin lens is used with an APS-size image sensor, the inner portions of the image circles IC4R and IC4L are not vignetted, but the outer portions are. For this reason, for an APS-size image sensor, the diameters of the image circles IC3R and IC3L must be smaller than those of the image circles IC4R and IC4L. Furthermore, the distance d3 between the centers OA3R and OA3L of the image circles IC3R and IC3L must be narrower than the distance d4 between the centers OA4R and OA4L of the image circles IC4R and IC4L.

[0034] To narrow the center distance d3 between the image circles IC3R and IC3L, the size of the adjustment parts (eccentric rollers, screws, springs, etc.) provided for optical adjustments such as decentering adjustment of the lenses that make up each of the two optical systems of the imaging lens must be reduced to a magnification proportional to the ratio between full size and APS size. However, this would make it difficult to maintain the strength of the adjustment parts and make assembly difficult.

[0035] FIG. 17 shows the holding structure for the third lens group (rear lens) in one optical system, as viewed from the optical axis direction, when designed using eccentric rollers of the same size as a full-frame twin lens. The rear lens is held by a third lens group holder 920, which is held by a third lens group base 910 via eccentric rollers 901A-901E. In a typical holding structure, three eccentric rollers are arranged at equal intervals of 120° around the optical axis. However, the holding structure shown in FIG. 17 has five eccentric rollers 901A-901E arranged at intervals other than 120°. With 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°. With this configuration, movement of the third lens group holder 920 is restricted in the left-right direction in the figure during eccentricity adjustment, but the restriction on movement in the up-down direction is weaker, making the third lens group holder 920 prone to rattle. As a result, it becomes difficult to perform good eccentricity adjustment.

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

[0037] Fig. 7 shows the optical unit as seen from above. Fig. 8 shows the holding mechanism for the third lens group as seen from the image side (lens mount side), and shows a cross section passing through the central axis of rotation of the eccentric rollers described below (cross section taken along line DD in Fig. 7). This cross section is a plane perpendicular to the third optical axes OA3R and OA3L. Furthermore, Fig. 9 shows the eccentric rollers 236 serving as adjustment members as seen from the direction of their central axis of rotation, and Fig. 10 shows the eccentric rollers 236 as seen obliquely. The eccentric rollers 236 and coaxial rollers described below correspond to fixing members capable of fixing the third group holder 234 shown in Fig. 8 in the cross section of Fig. 8.

[0038] 9 and 10, a screw hole 236c into which a roller mounting screw is inserted is formed on the inside of the eccentric roller 236. The roller mounting screw inserted into the screw hole 236c is fastened into the third group holder 234, thereby mounting the eccentric roller 236 to the third group holder 234.

[0039] 10, eccentric roller 236 has small diameter portion 236b with a small outer diameter and large diameter portion 236a with a large outer diameter. Small diameter portion 236b is formed coaxially with inner screw hole 236c, and large diameter portion 236a is formed with its central axis misaligned with small diameter portion 236b and screw hole 236c (i.e., eccentric).

[0040] 9 and 10, a slot (notch) 236d is formed at the upper end of the large diameter portion 236a. The slot 236d is a portion into which a tool such as a flathead screwdriver engages, and turning the tool allows the eccentric roller 236 to rotate about its central axis of rotation (the central axis between the small diameter portion 236b and the screw hole 236c). On the other hand, the coaxial roller 237 shown in FIG. 8 is formed coaxially as a whole and does not require a tool to turn it, so no slot is formed.

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

[0042] As described 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 base 233 by having the entire outer periphery thereof thermally caulked to the third lens base 233. As shown in FIGS. 11 and 12, the third lens base 233 has a wall portion 233d having a D-shaped cutout in the circumferential direction of its basic cylindrical shape. The third lens groups 231R and 231L are fixed to the lens holding members 223R and 223L, respectively, with screws 239.

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

[0044] 11 and 12, a first hole 233a, a second hole 233b, and a third hole 233c are formed in a wall portion 233d of the three-group base 233. The first to third hole portions 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 hole portions 233a to 233c intersect at a point P that passes through the central axis of an arc that follows the wall portion 233d, as shown in FIG.

[0045] 13, the center of the rear lens 231b that holds the third group holder 234 (rear lens 231b) in the third group base 233 is on the third optical axis OA3L that is located closer to the D-cut portion or Z plane (when the rear lens 231b in FIG. 13 is the third lens group 231L of the left-eye optical system, the third 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 hole portions 233a to 233c intersect with each other is located farther from the third lens group 231R than the lens optical axis of the rear lens 231b (third lens group 231L of the left-eye optical system).

[0046] The same eccentric roller 236 is inserted into first hole 233a and second hole 233b, and the eccentric rollers inserted into each hole are referred to as eccentric rollers 236A and 236B, respectively. Outer diameter portions 236a of eccentric rollers 236A and 236B fit into the inner peripheral surfaces of first hole 233a and second hole 233b, respectively. Eccentric roller 236C similar to eccentric rollers 236A and 236B or coaxial roller 237 is inserted into third hole 233c, and large diameter portion 236a of eccentric roller 236C or the outer peripheral surface of coaxial roller 237 fits into the inner peripheral surface of third hole 233c.

[0047] Eccentric rollers 236A, 236B and eccentric roller 236C or coaxial roller 237 are inserted into first roller seats 234a, second roller seats 234b, and third roller seats 234c, which are provided at three circumferential locations on the outer periphery of third holder 234 at equal intervals of 120°. Small diameter portions 236b of each eccentric roller or small diameter portions (not shown) on the outer periphery of coaxial roller 237 fit into the inner periphery of the corresponding roller seat. Each roller is rotatably attached to third holder 234 with a screw.

[0048] 13, the first roller seat 234a and the second roller seat 234b are disposed so as to have a vertically symmetrical positional relationship with respect to a line (plane) that passes through point P and a point on the third optical axis OA3L in the drawing. The respective central axes of the first roller seat 234a, the second roller seat 234b, and the third roller seat 234c intersect with each other at point P. That is, point P, where the central axes of the first to third roller seats 234a to 234c intersect with each other, is also located farther from the third lens group 231R than the lens optical axis of the rear lens 231b (third lens group 231L), as is the point of intersection of the central axes of the first to third hole portions 233a to 233c of the third group base 233. In other words, the rotational center axes of the eccentric rollers 236A, 236B and eccentric roller 236C or coaxial roller 237 inserted into the first to third roller seats 234a to 234c also intersect with each other at a point P (hereinafter referred to as the roller axis intersection point) that is farther 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 roller seats 234a and 234b are offset from the third optical axis OA3L, the first and second roller seats 234a and 234b are disposed closer to the rear lens 231b than the third roller seat 234c. The central axis of the third roller seat 234c intersects with the third optical axis OA3L.

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

[0051] Furthermore, the first to third roller seats 234a to 234c (eccentric rollers 236A to 236C or coaxial roller 237) do not necessarily have to be arranged at strictly 120° intervals; they may be arranged at positions slightly offset (for example, within 10°) from the strictly 120° intervals. In other words, they may be arranged at intervals based on 120° intervals (equivalent to 120° intervals). Furthermore, the central axes of the first to third roller seats 234a to 234c do not necessarily have to intersect at a single point. As long as the intersection of the central axes of the first and second roller seats 234a and 234b is offset from the third optical axis OA3L and is located farther from the Z plane or OA3R than the third optical axis OA3L, the central axis of the third roller seat 234c does not have to intersect with the optical axis OA3L.

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

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

[0054] Three tension springs 238 are provided that generate a biasing force to prevent displacement of the rear lens 231b in the optical axis direction and the circumferential direction caused by fit play in the holes of the above-mentioned eccentric rollers. The tension springs 238 are hooked obliquely with respect to the optical axis direction between a hook 234e provided on the third group holder 234 and a hook 233e provided on the third group base 233 shown in Fig. 11. As a result, the tension springs 238 bias the third group holder 234 in one circumferential direction relative to the third group base 233, and also bias the third group holder 234 in directions approaching each other in the optical axis direction.

[0055] As shown in FIG. 13, one tension spring 238 and the hook 233e attached thereto are disposed beyond the Z plane in the right-eye region 20R. Similarly, one tension spring 238 and the hook 233e attached thereto are disposed beyond the Z plane in the right-eye region 20L. To enable such an arrangement, as shown in FIGS. 11 and 13, each of the left and right holding mechanisms (third group bases 233) has a recess 233f. The recess 233f of one holding mechanism forms a space in which the tension spring 238 and the hook 233e, which are part of the other holding mechanism, are disposed. In other words, the recess 233f is provided to prevent interference between the tension spring 238 and the hook 233e and one holding mechanism.

[0056] Left and right third-group bases 233, which respectively hold third lens groups 231R and 231L, are fixed to lens holding members 223R and 223L, which are further fixed to lens top base 300, thereby integrating the left and right holding mechanisms. As shown in FIGS. 11 to 13, no eccentric rollers are provided on the Z-plane side of the left and right holding mechanisms. Instead, eccentric rollers 236A and 236B and eccentric roller 236C or coaxial roller 237 are disposed in portions other than the Z-plane side. Therefore, with the left and right holding mechanisms integrated, all eccentric rollers can be accessed from the radial outside of each holding mechanism, allowing optical adjustment of rear lens 231b by rotating each eccentric roller. Furthermore, because the roller mounting screws inserted into the inner periphery of eccentric roller 236C are also accessible, replacement of eccentric roller 236C and coaxial roller 237 can be easily performed.

[0057] Next, optical adjustment (eccentricity adjustment) of the rear lens 231b will be described with reference to Figures 13 and 14. Here, a case will be described in which three eccentric rollers 236A, 236B, and 236C are provided in the left holding mechanism. Figure 14 shows an enlarged view of the vicinity of the optical axis OA3L of the third lens group 231R in Figure 13, and shows the movement locus of the lens optical axis of the rear lens 231b due to eccentricity adjustment.

[0058] 13, the points where three straight lines perpendicular to the central axes of rotation of the three eccentric rollers 236A to 236C intersect are designated as A, B, and C. Points A, B, and C are the vertices of a triangle shown in the drawing.

[0059] When one of the three eccentric rollers 236A to 236C is rotated, the third group holder 234 and the rear lens 231b fixed thereto rotate around the corresponding point A, B, or C from the position where the three eccentric rollers 236A to 236C fit into and contact the third group base 233. For example, when the eccentric roller 236A is rotated, the lens optical axis of the rear lens 231b rotates around point A, as shown by the two-dot chain arc in Fig. 13. When the eccentric rollers 236B and 236C are rotated, the lens optical axis of the rear lens 231b rotates around point B and point C, respectively. This is because the two eccentric rollers other than the rotating eccentric roller are fitted circumferentially to the third group base 233, and the third group holder 234 can only move in the direction of the rotation center axis of each eccentric roller, so the third group holder 234 moves to describe an arc locus tangent to the rotation center axes of the two non-rotating eccentric rollers. In this way, the lens optical axis of the rear lens 231b rotates and moves to describe an arc locus centered on point A, B, or C by rotating each eccentric roller.

[0060] In the case of a normal monocular lens, decentering adjustment is performed so that the lens optical axis of the lens to be adjusted coincides with the position of the intersection where the rotation central axes of multiple eccentric rollers intersect. In contrast, in this embodiment, the roller axis intersection P, where the rotation central axes of at least two eccentric rollers 236A and 236B (and also eccentric roller 236C) intersect with each other, is located farther from the Z plane and the right-eye optical system 201R than the lens optical axis (third optical axis OA3L) of the rear lens 231b.

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

[0062] In FIG. 14, the rotation of the eccentric roller 236A causes the lens optical axis of the rear lens 231b to move on an arcuate locus from +Vα to -Vα around point A. The rotation of the eccentric roller 236B causes the lens optical axis of the rear lens 231b to move on an arcuate locus from +Vβ to -Vβ around point B. The rotation of the eccentric roller 236C causes the lens optical axis of the rear lens 231b to move on an arcuate locus from +Vγ to -Vγ around point C. 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 amount of eccentricity of the three eccentric rollers 236A to 236C is the same, the angle through which the lens optical axis of the rear lens 231b moves on the arcuate locus will be the same, 37 minutes, as shown in FIG. 13. However, because the radius of the arcuate locus passing through ±Vγ is smaller than the radii of the other arcuate loci as described above, the amount of movement of the lens optical axis of rear lens 231b when eccentric roller 236C is rotated is smaller than when eccentric rollers 236A and 236B are rotated. Because points A and B are located in vertically symmetrical positions as shown in Figure 13, the amount of movement of the lens optical axis of rear lens 231b when eccentric rollers 236A and 236B are rotated is the same.

[0063] In addition, since the roller axis intersection point P is located inside the circular arc locus that passes through the third optical axis OA3L and has points A and B as its center, the radius of the circular locus is larger than when the roller axis intersection point is located on the third optical axis OA3L as in a normal monocular lens. Therefore, the movement amount of the lens optical axis of the rear lens 231b centered on points A and B is larger than when the roller axis intersection point is located on the third optical axis OA3L.

[0064] By combining these three arc loci, the lens optical axis of the rear lens 231b can move within a roughly hexagonal area AREA (Vα, Vβ, Vγ) indicated by the dashed lines in Fig. 14. Each arc locus is a small part of the entire circle that contains it, and therefore can be approximated by a straight line.

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

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

[0067] In contrast, when the same eccentric rollers are used for the three eccentric rollers 236A-236C, the lens optical axis of the rear lens 231b can be moved by a larger distance than when the coaxial roller 237 is used. Furthermore, the movement of the lens optical axis of the rear lens 231b relative to the amount of rotation of the eccentric roller 236C is smaller than the movement of the lens optical axis relative to the same amount of rotation of the eccentric rollers 236A and 236B. This allows for an adjustment procedure in which the eccentric rollers 236A and 236B are rotated to perform coarse adjustment of the lens optical axis of the rear lens 231b primarily in the horizontal direction, and then the eccentric roller 236C is rotated to perform fine adjustment primarily in the vertical direction. Another adjustment procedure is also possible in which the coaxial roller 237 is first used to rotate the eccentric rollers 236A and 236B to perform eccentric adjustment of the lens optical axis of the rear lens 231b, and if the adjustment is insufficient, the coaxial roller 237 is replaced with the eccentric roller 236C and readjustment is then performed.

[0068] The adjustment work is performed with the optical unit in the state shown in FIG. 5. After adjusting the positions of the left and right rear lens elements 231b in the optical unit in the eccentricity direction to positions that provide the best optical performance, the third group holder 234 is adhesively fixed to the third group base 233. At this time, as shown in FIG. 11, adhesive is filled into the gap between the hole 234d formed in the third group holder 234 and the protrusion 233g of the third group base 233 inserted therein. After this bonding, to improve the appearance and prevent the intrusion of dust and water droplets, third group sheets 235, which are dustproof and waterproof members, are attached and fixed to the left and right third group bases 233, respectively, as shown in FIGS. 6 and 7.

[0069] According to this embodiment, the left and right third lens groups 231R, 231L can be placed close to each other and can be housed within the lens mount 202. Furthermore, the holding mechanisms that enable optical adjustment of each of the third lens groups 231R, 231L are configured using the same parts and are arranged rotationally symmetrically about the central axis of the lens mount 202 (the axis between the third lens groups 231R, 231L), so that the manufacture of the imaging lens 200 can be simplified.

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

[0071] The camera 110 has 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 start communication.

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

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

[0074] The camera control unit 117 is configured with a CPU and the like, and controls the operation of the camera 110 and also controls 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 stereoscopic images (right eye image and left eye image) that have parallax and can be viewed stereoscopically by capturing images. The stereoscopic images are viewed in stereo by an observer through an image display device such as VR goggles.

[0076] The above embodiment includes the following configurations.

[0077] (Configuration 1) Two optical systems arranged in parallel, a holding member for holding a lens included in one of the two optical systems; three fixing members that can fix the holding member in a plane perpendicular to the optical axis of the lens, the fixing members including at least two adjustment members that can move the holding member in the plane by rotating around different rotation central axes; A stereo lens device characterized in that, when viewed from the optical axis direction, the intersection point where the rotation center axes of the at least two adjustment members intersect with each other is located farther from the other of the two optical systems than the optical axis of the lens. (Configuration 2) The stereo lens device according to configuration 1, wherein the three fixing members are arranged at intervals of 120° in the circumferential direction around the intersection. (Configuration 3) 3. The stereo lens device according to claim 1, wherein the adjustment member is an eccentric roller. (Configuration 4) All of the three fixed members are the eccentric rollers, The stereo lens device according to configuration 3, wherein the two eccentric rollers are arranged closer to the optical axis of the lens than the one eccentric roller. (Configuration 5) The stereo lens device according to configuration 4, wherein the movement amount of the holding member for the same amount of rotation when the two eccentric rollers are rotated is different from the movement amount of the holding member for the same amount of rotation when the one eccentric roller is rotated. (Configuration 6) Two of the three fixing members are the eccentric rollers and one is a coaxial roller, 4. The stereo lens device according to configuration 3, wherein the two eccentric rollers are arranged closer to the optical axis of the lens than the coaxial rollers. (Configuration 7) the holding member and the three fixing members are provided for each of the two optical systems, The stereo lens device according to any one of configurations 1 to 6, wherein 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. (Configuration 8) the two optical systems each include a reflecting surface, and the optical axis spacing of a portion of the two optical systems on the image side of the reflecting surface is narrower than the optical axis spacing of a portion of the two optical systems on the object side of the reflecting surface, 8. The stereo lens device according to any one of configurations 1 to 7, wherein the lens is included in the image-side portion. (Configuration 9) The stereo lens device according to any one of configurations 1 to 8, and a single imaging element that captures 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 realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0079] The embodiments described above are merely representative examples, and various modifications and alterations are possible 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 3-group base 234 3rd 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; three fixing members that can fix the holding member in a plane perpendicular to the optical axis of the lens, the fixing members including at least two adjustment members that can move the holding member in the plane by rotating around different rotation central axes; A stereo lens device characterized in that, when viewed from the optical axis direction, the intersection point where the rotation center axes of the at least two adjustment members intersect with each other is located farther from the other of the two optical systems than the optical axis of the lens.

2. 2. The stereo lens device according to claim 1, wherein the three fixing members are arranged at intervals of 120 degrees in a circumferential direction around the intersection point.

3. 2. The stereo lens device according to claim 1, wherein the adjustment member is an eccentric roller.

4. All of the three fixed members are the eccentric rollers, 4. The stereo lens device according to claim 3, wherein the two eccentric rollers are arranged closer to the optical axis of the lens than the one eccentric roller.

5. 5. The stereo lens device according to claim 4, wherein the amount of movement of the holding member for the same amount of rotation when the two eccentric rollers are rotated is different from the amount of movement of the holding member for the same amount of rotation when the one eccentric roller is rotated.

6. Two of the three fixing members are the eccentric rollers and one is a coaxial roller, 4. The stereo lens device according to claim 3, wherein the two eccentric rollers are arranged closer to the optical axis of the lens than the coaxial rollers.

7. the holding member and the three fixing members are provided for each of the two optical systems, 2. The stereo lens device according to claim 1, wherein the three fixing members provided for the two optical systems are arranged rotationally symmetrically with respect to an axis between the two optical systems.

8. the two optical systems each include a reflecting surface, and the optical axis spacing of a portion of the two optical systems on the image side of the reflecting surface is narrower than the optical axis spacing of a portion of the two optical systems on the object side of the reflecting surface, 2. The stereo lens device according to claim 1, wherein the lens is included in the image-side portion.

9. The stereo lens device according to any one of claims 1 to 8, and a single image sensor for capturing two optical images formed by the two optical systems of the stereo lens device.

Images