Lens device, and imaging apparatus comprising the same

Abstract

To provide a lens device in which performance difference between right and left optical systems can be restricted.SOLUTION: A lens device comprises: a base member in which a first aperture corresponding to a first optical system and a second aperture corresponding to a second optical system are formed; and a holding member holding the base member, the base member comprises: a first positioning portion which is formed at a position away from a center of the first aperture and a center of the second aperture; and a second positioning portion which is formed at a position facing the first positioning portion with respect to a middle point of the first aperture center and the second aperture center, and which regulates rotation of the base member around an optical axis relative to the holding member.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a lens apparatus and an imaging apparatus having the same. [Background technology]

[0002] In a stereoscopic imaging device, if the deviations of the optical axes of the left and right optical systems arranged in parallel to the image sensor from their designed nominal positions become uneven, it will directly lead to deterioration of the optical performance and stereoscopic images, so it is important to equalize the deviations of the left and right optical systems. As positioning configurations for multiple optical systems, a surface butting configuration (see Patent Document 1) and a configuration in which a positioning unit for the rotation center is provided at the center of the unit (see Patent Document 2) have been disclosed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4378434 [Patent Document 2] Patent No. 6561840 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the configuration of Patent Document 1, the amount of left and right misalignment becomes unequal by the orthogonality of the two planes that serve as the abutment surfaces. In addition, in the configuration of Patent Document 2, the amount of left and right misalignment can be made equal, but there is a possibility that the positioning part cannot be placed at the center of the unit due to space limitations.

[0005] An object of the present invention is to provide a lens device capable of suppressing the difference in performance between the left and right optical systems. [Means for solving the problem]

[0006] A lens device according to one aspect of the present invention has a base member in which a first opening corresponding to a first optical system and a second opening corresponding to a second optical system are formed, and a holding member for holding the base member, wherein the base member is characterized by having a first positioning portion formed at a position away from the center of the first opening and the center of the second opening, and a second positioning portion formed at a position opposite the first positioning portion with respect to the midpoint between the centers of the first opening and the second opening, and which restricts rotation of the base member about the optical axis relative to the holding member. Effect of the Invention

[0007] According to the present invention, it is possible to provide a lens device capable of suppressing the difference in performance between the left and right optical systems. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of an imaging device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of a light amount control device. [Diagram 3] FIG. 2 is a schematic diagram of a light amount control device. [Figure 4] FIG. [Diagram 5] FIG. 13 is a diagram illustrating an example of a positioning configuration. [Figure 6] FIG. 11 is an explanatory diagram of a problem that occurs when the present invention is not applied. [Figure 7] FIG. 4 is an explanatory diagram of the application range of the positioning configuration of the present invention. [Figure 8] FIG. 13 is a diagram showing another example of a positioning configuration. [Figure 9] FIG. 1 is a diagram showing an optical system to which the present invention is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to refer to the same components, and duplicated descriptions will be omitted.

[0010] 1 is a schematic diagram of an image capturing apparatus 10 according to an embodiment of the present invention. The image capturing apparatus 10 has a camera body 1 and a stereo optical unit (lens device) 20 fixed integrally to the camera body 1.

[0011] The stereo optical unit 20 includes a first optical unit 2 and a second optical unit 3. In this embodiment, the stereo optical unit 20 is fixed integrally to the camera body 1, but may be configured to be detachable from the camera body 1. The first optical unit 2 includes a first optical system 201, a lens control unit 204, and a lens communication unit 205. The second optical unit 3 includes a second optical system 301, a lens control unit 304, and a lens communication unit 305. The first optical system 201 and the second optical system 301 have the same optical configuration and are arranged in parallel on the left and right so that their optical axes OA1 and OA2 are parallel to each other. In the following description, the direction in which the optical axes OA1 and OA2 extend is referred to as the optical axis direction. The first optical system 201 and the second optical system 301 move along the optical axis direction for zooming and focusing by a zoom motor and a focus motor as driving sources (not shown). The first optical system 201 and the second optical system 301 may be composed of one or more lenses, or may include optical elements other than lenses such as a prism, a mirror, etc. The first optical system 201 and the second optical system 301 may include a shift lens that moves in a direction perpendicular to the optical axes OA1 and OA2 (direction perpendicular to the optical axes) in response to shaking of the imaging device 10 due to hand shake or the like to reduce (correct) image shake.

[0012] Moreover, the stereo optical unit 20 has one light amount control device 100 provided in common for the first optical system 201 and the second optical system 301. The light amount control device 100 includes a first diaphragm provided for the first optical system 201, a second diaphragm provided for the second optical system 301, and a diaphragm motor 505 provided as a single drive source in common for the first diaphragm and the second diaphragm. The diaphragm motor 505 moves the first diaphragm and the second diaphragm, thereby changing the diameter of the diaphragm opening formed by the first diaphragm and the second diaphragm, and the light amount is controlled (adjusted).

[0013] Moreover, the stereo optical unit 20 has a lens holding section 400 that integrally holds the lenses of the first optical system 201 and the second optical system 301, and a lens holding section 401 that individually holds the lenses of the first optical system 201 and the second optical system 301. The object of the present invention is to reduce (suppress) the amount of misalignment between the center of each optical system and the corresponding optical axis when a unit that integrally holds the first optical system 201 and the second optical system 301 is assembled to a holding member (e.g., a lens barrel) provided in the stereo optical unit 20. Therefore, the present invention is applicable to the lens holding section 400 that integrally holds the first optical system 201 and the second optical system 301, and is also applicable to the light amount control device 100.

[0014] The lens control units 204 and 304 respectively control a zoom motor and a focus motor in response to a zoom command and a focus command from the camera body 1 via the lens communication units 205 and 305. In addition, the lens control unit 204 controls the aperture motor 505 based on an aperture command from the camera body 1 via the lens communication unit 205.

[0015] The camera body 1 has a first imaging element 12, a second imaging element 13, a camera control unit 14, and camera communication units 15 and 16. The first imaging element 12 photoelectrically converts (captures) a subject image formed by a first optical system 201. The second imaging element 13 photoelectrically converts a subject image formed by a second optical system 301. The first imaging element 12 and the second imaging element 13 are photoelectric conversion elements such as a CMOS sensor or a CCD sensor.

[0016] The camera control unit 14 transmits various commands to the lens control units 204 and 304 via the camera communication units 15 and 16 and the lens communication units 205 and 305. The camera control unit 14 is provided with an image processing unit (not shown) that performs various processes on the imaging signals from the first imaging element 12 and the second imaging element 13 to generate first image data and second image data. The first image data and the second image data are displayed on an observation device such as a monitor or a head-mounted display as images for the right eye and the left eye, respectively, so that the observer can observe a stereoscopic image. In this embodiment, the camera body 1 is provided with two imaging elements for the two optical systems, but may be configured to obtain imaging signals for generating the first and second image data in two regions on a single imaging element provided for the two optical systems.

[0017] 2 and 3 are schematic diagrams of the light amount control device 100. FIG. 4 is an exploded view of the light amount control device 100. The light amount control device 100 includes a first aperture including a plurality of blade members 502 for the first optical system 201, a second aperture including a plurality of blade members 502 for the second optical system 301, and an opening / closing mechanism for opening and closing the blade members 502. In this embodiment, seven blade members 502 are provided for each aperture. The opening / closing mechanism includes an aperture motor (driving source) 505, an aperture base plate (base member) 501, a stepped gear (relay gear) 504, a first driving ring (first rotating member) 520, a second driving ring (second rotating member), and a second cam plate (pressing member).

[0018] The aperture motor 505 is a stepping motor, and a pinion gear 503 (drive gear) is fixed to the rotary drive shaft so as to be rotatable integrally with the aperture motor 505. The aperture motor 505 is fixed to the aperture base plate 501 with a screw. The pinion gear 503 protrudes from a hole formed in the aperture base plate 501 towards the stepped gear 504 side.

[0019] A first opening corresponding to the first optical system 201 and a second opening corresponding to the second optical system 301 are formed in the diaphragm base plate 501. The diaphragm base plate 501 is held by a holding member (e.g., a lens barrel) (not shown) provided in the stereo optical unit 20. The diaphragm base plate 501 abuts against the holding member in the optical axis direction, and the position and angle in the direction perpendicular to the optical axis are determined.

[0020] A plurality of fitting receiving portions are formed along the circumferential direction on the inner periphery of the first opening. Fitting portions provided on the outer periphery of a first driving ring 520 fit into the plurality of fitting receiving portions. The first driving ring 520 is held rotatably around the central axis of the first opening (i.e., around the optical axis OA1 of the first optical system 201) relative to the diaphragm base plate 501. This forms a first diaphragm 530 corresponding to the first optical system 201.

[0021] A plurality of fitting receiving portions are formed along the circumferential direction on the inner periphery of the second opening. Fitting portions provided on the outer periphery of a second driving ring 521 fit into the plurality of fitting receiving portions. The second driving ring 521 is held rotatably around the central axis of the second opening (i.e., around the optical axis OA2 of the second optical system 301) relative to the diaphragm base plate 501. This forms a second diaphragm 531 corresponding to the second optical system 301.

[0022] When the aperture motor 505 is driven and the pinion gear 503 rotates, the first driving ring 520 and the second driving ring 521 rotate in the same direction relative to the aperture base plate 501 via the stepped gear 504 .

[0023] The first cam plate 510 is disposed so as to sandwich the first driving ring 520 and the plurality of blade members 502 between the first cam plate 510 and the diaphragm base plate 501, and is fixed to the diaphragm base plate 501 with screws. The second cam plate 511 is disposed so as to sandwich the second driving ring 521 and the plurality of blade members 502 between the first cam plate 510 and the diaphragm base plate 501, and is fixed to the diaphragm base plate 501 with screws. The cam pins of the blade members 502 are engaged with the corresponding cam grooves of the cam plate. With this configuration, when the first driving ring 520 and the second driving ring 521 rotate, the blade members 502 move in the circumferential direction together with the driving rings. In addition, the cam pins of the blade members 502 move along the cam grooves of the cam plate with which they are engaged, and the blade members 502 rotate (pivot) in the opening and closing direction. This changes the diameter (aperture value) of the aperture opening formed in each of the first diaphragm 530 and the second diaphragm 531.

[0024] The positioning configuration of this embodiment will be described below. Fig. 5 is a diagram showing an example of the positioning configuration. The line passing through the optical axes OA1 and OA2 is defined as the X-axis (horizontal direction on the paper), the bisector of the line connecting the optical axes OA1 and OA2 is defined as the Y-axis (vertical direction on the paper), and the origin is defined as OM. In the following description, the above coordinate axes will be used.

[0025] The diaphragm base plate 501 is formed with a positioning hole (first positioning portion) 600 and an elongated hole (second positioning portion) 601 that restricts the rotation of the diaphragm base plate 501 around the optical axis. The positioning hole 600 is formed at a position away from the center of the first opening and the center of the second opening. In this embodiment, when the distance [mm] from the positioning hole 600 to the center of the first opening is r1 and the distance [mm] from the positioning hole 600 to the center of the second opening is r2, the positioning hole 600 is disposed so that the distances r1 and r2 are equidistant. Here, the equidistant includes not only the case where they are strictly equal, but also the case where they are substantially equidistant (approximately equidistant). The elongated hole 601 is disposed at a position that is approximately symmetrical to the positioning hole 600 with respect to the X-axis, that is, at a position that faces the positioning hole 600 with respect to the midpoint of the first and second openings. In FIG. 5, as an example, the positioning hole 600 is disposed at the 12 o'clock position and the elongated hole 601 is disposed at the 6 o'clock position. When the light amount control device 100 is attached to the holding member of the stereo optical unit 20, an angle tolerance (mounting angle intersection) [°]θ may occur. In this case, a difference ΔL1 between the aperture center of the first aperture 530 and the optical axis OA1 and a difference ΔL2 between the aperture center of the second aperture 531 and the optical axis OA2 occur. However, the differences ΔL1 and ΔL2 are equal, and the performance difference between the left and right optical systems can be suppressed (reduced).

[0026] Here, the problem when the present invention is not applied will be described. Fig. 6 is an explanatory diagram of the problem when the present invention is not applied. In Fig. 6, the positioning hole 610 is disposed at the 3 o'clock position, and the long hole 611 is disposed at the 9 o'clock position. In this case, the distance r1' from the positioning hole 610 to the center of the aperture of the first aperture 530 is different from the distance r2' from the positioning hole 610 to the center of the aperture of the second aperture 531, and the difference ΔL2 is larger than the difference ΔL1. This causes the problem of degradation of optical performance and stereo images.

[0027] In this embodiment, the configuration and effect of arranging the positioning hole 600 at a position where the distance r1 from the optical axis OA1 and the distance r2 from the optical axis OA2 are approximately equal is described. Here, the definition of approximately equal distance that obtains the effect of the present invention is described. FIG. 7 is an explanatory diagram of the application range of the positioning configuration of the present invention, and shows a state where the positioning hole 600 is arranged at a position away from the center of the light amount control device 100 (aperture base plate 501) by a distance S in the X-axis direction and a distance T in the Y-axis direction. In this case, the distance r1 from the positioning hole 600 to the optical axis OA1 and the distance r2 from the positioning hole 600 to the optical axis OA2 can be calculated using the following formulas (1) and (2), respectively.

[0028]

number

[0029] (1)

[0030]

number

[0031] (2) Here, B is the distance [mm] between the center of the first opening and the center of the second opening.

[0032] As mentioned above, an angle tolerance θ occurs when the light amount control device 100 is assembled into the stereo optical unit 20, so the difference ΔL1 with the optical axis OA1 and the difference ΔL2 with the optical axis OA2 can be calculated using the following equations (3) and (4), respectively.

[0033] ΔL1=r1×tanθ (3) ΔL2=r2×tanθ (4) The allowable value of the relative difference between the differences ΔL1 and ΔL2 is set to, for example, 0.05 mm as shown in the following formula (5).

[0034] |ΔL2-ΔL1|<0.05 (5) At this time, it is possible to determine the range of the position coordinates (S, T) of the positioning holes 600 that satisfy the formulas (1) to (5). In this way, the effects of the present invention can be obtained even in a range in which the positions of the positioning holes 600 can be considered to be approximately equidistant.

[0035] It is preferable that the numerical range of formula (5) is the numerical range of the following formula (5a).

[0036] |ΔL2-ΔL1|<0.04 (5a) It is further preferable that the numerical range of the formula (5) is the numerical range of the following formula (5b).

[0037] |ΔL2-ΔL1|<0.03 (5b) Moreover, the positioning configuration is not limited to the example of FIG. 5. FIG. 8 is a diagram showing another example of the positioning configuration. The lens barrel 800 has a receiving portion (third positioning portion) 801 that abuts on the outer diameter (outer peripheral surface) of the light amount control device 100 (aperture base plate 501) at least three places. The receiving portion 801 allows the light amount control device 100 (aperture base plate 501) to have a virtual center of rotation (virtual center). With this configuration, even if the center of rotation cannot be provided at the center of the light amount control device 100 due to space issues, the center of rotation can be located at the center of the light amount control device 100. As a result, for example, if a mounting angle tolerance of the light amount control device 100 occurs in the clockwise direction, the difference ΔL1 occurs in the +Y axis direction and the difference ΔL2 occurs in the -Y axis direction, but the amount of deviation is equal. Therefore, the performance difference between the left and right optical systems can be suppressed (reduced).

[0038] Furthermore, in this embodiment, the case where the present invention is applied to a light amount control device has been described, but the present invention may also be applied to an optical system in which a lens 700 is held as shown in FIG.

[0039] The disclosure of this embodiment includes the following configuration. (Configuration 1) a base member in which a first opening corresponding to the first optical system and a second opening corresponding to the second optical system are formed; a holding member for holding the base member, The lens device is characterized in that the base member includes a first positioning portion formed at a position away from the center of the first opening and the center of the second opening, and a second positioning portion formed at a position opposite the first positioning portion with respect to the midpoint between the center of the first opening and the center of the second opening, and regulating rotation of the base member about the optical axis relative to the holding member. (Configuration 2) When the lens device is viewed in the optical axis direction, the distance [mm] between the center of the first opening and the center of the second opening is B, the coordinates of the center of the first positioning part when the center of the base member is the origin are (S, T), the distance [mm] from the center of the first positioning part to the center of the first opening is r1, the distance [mm] from the center of the first positioning part to the center of the second opening is r2, and the angle tolerance [°] of the base member with respect to the holding member is θ,

[0040]

number

[0041]

number

[0042] |r2-r1|×tan θ<0.05 2. The lens device according to claim 1, wherein the following formula is satisfied: (Configuration 3) a base member in which a first opening corresponding to the first optical system and a second opening corresponding to the second optical system are formed; a holding member for holding the base member, the base member includes a second positioning portion that restricts rotation of the base member relative to the holding member about the optical axis, The lens device, wherein the holding member is provided with a third positioning portion that abuts against the outer peripheral surface of the base member at at least three points and determines the center of the base member. (Configuration 4) 4. The lens device according to any one of configurations 1 to 3, wherein the base member abuts against the holding member in the optical axis direction, and a position and angle in a direction perpendicular to the optical axis are determined. (Configuration 5) 3. The lens device according to claim 1, wherein the first positioning portion is formed at a position equidistant from a center of the first opening and a center of the second opening. (Configuration 6) A lens device according to any one of configurations 1 to 5; an image sensor for photoelectrically converting an object image formed by the lens device,

[0043] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0044] 20 Stereo optical unit (lens device) 201 1st optical system 301 Second optical system 501 Drawing base plate (base material) 600 Positioning hole (first positioning part) 601 Oblong hole (second positioning part)

Claims

1. a base member in which a first opening corresponding to the first optical system and a second opening corresponding to the second optical system are formed; a holding member for holding the base member, The lens device is characterized in that the base member comprises a first positioning portion formed at a position away from the center of the first opening and the center of the second opening, and a second positioning portion formed at a position opposite the first positioning portion with respect to the midpoint between the center of the first opening and the center of the second opening, and regulating rotation of the base member about the optical axis relative to the holding member.

2. When the lens device is viewed in the optical axis direction, the distance [mm] between the center of the first opening and the center of the second opening is B, the coordinates of the center of the first positioning portion when the center of the base member is the origin are (S, T), the distance [mm] from the center of the first positioning portion to the center of the first opening is r1, the distance [mm] from the center of the first positioning portion to the center of the second opening is r2, and the angle tolerance [°] of the base member with respect to the holding member is θ, [0010] [0025] |r2-r1|×tanθ<0.05 2. The lens device according to claim 1, wherein the following formula is satisfied:

3. a base member in which a first opening corresponding to the first optical system and a second opening corresponding to the second optical system are formed; a holding member for holding the base member, the base member includes a second positioning portion that restricts rotation of the base member relative to the holding member about the optical axis, The lens device according to claim 1, wherein the holding member is provided with a third positioning portion that abuts against an outer peripheral surface of the base member at at least three points and determines a center of the base member.

4. 4. The lens device according to claim 1, wherein the base member abuts against the holding member in the optical axis direction, and a position and angle in a direction perpendicular to the optical axis are determined.

5. The lens device according to claim 1 , wherein the first positioning portion is formed at a position equidistant from a center of the first opening and a center of the second opening.

6. A lens device according to any one of claims 1 to 3; an image sensor for photoelectrically converting an object image formed by the lens device,

Images