Light quantity control device and optical appliance

Abstract

To control the light quantity while obtaining a suitable blur style with one driving source for two optical systems.SOLUTION: A light quantity regulation device 100 includes one driving source 105, a base member 101 that keeps the driving source and has a first opening part corresponding to a first optical system 201 and a second opening part corresponding to a second optical system 301, a first diaphragm that forms a diaphragm opening for light passing through the first opening part, a second diaphragm that forms a diaphragm opening for light passing through the second opening part, a first rotatable member 120 that rotates about a center axis of the first opening part with respect to the base member, and a second rotatable member 121 that rotates about a center axis of the second opening part with respect to the base member. As the first and second rotatable members rotate, the first and second diaphragms, which are iris diaphragms, operate. As a driving gear 106 that is rotated by the driving source is engaged with a relay gear 107 and the relay gear is engaged with gear parts provided in the first and second rotatable members, the rotation of the driving source transmits to the first and second rotatable members.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a light amount control device provided for two optical systems arranged in parallel. [Background technology]

[0002] An optical device having two optical systems arranged in parallel to perform stereo imaging is provided with a light amount control device having an aperture that controls (adjusts) the amount of light for each optical system. Patent Document 1 and Patent Document 2 disclose light amount control devices that drive two apertures using a single drive source. In Patent Document 1, a single drive source drives two aperture blades provided in common for the two optical systems via a drive arm. In Patent Document 2, a single drive source drives two aperture blades provided for each of the two apertures via a lever member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-119615 A [Patent Document 2] Patent Publication No. 2021-056394 Summary of the Invention [Problem to be solved by the invention]

[0004] Simply providing one or two diaphragm blades for each optical system, as in the light quantity control devices disclosed in Patent Documents 1 and 2, makes it difficult to shape the diaphragm opening to produce a good blur effect in imaging.

[0005] The present invention provides a light amount control device that can control the amount of light while obtaining good bokeh with a single drive source for two optical systems, and an optical apparatus equipped with the same. [Means for solving the problem]

[0006] A light amount adjustment device according to one aspect of the present invention controls the amount of light in a first optical system and a second optical system arranged in parallel. The light amount control device includes a single drive source, a base member that holds the drive source and has a first opening corresponding to the first optical system and a second opening corresponding to the second optical system, a first diaphragm that forms an aperture for light passing through the first opening, a second diaphragm that forms an aperture for light passing through the second opening, a first rotating member that rotates around the central axis of the first opening relative to the base member, and a second rotating member that rotates around the central axis of the second opening relative to the base member. The first diaphragm and the second diaphragm are each an iris diaphragm having three or more blade members. The first and second diaphragms operate as the first and second rotating members rotate. A drive gear rotated by the drive source meshes with an intermediate gear, and the intermediate gear meshes with gear portions provided on the first and second rotating members, thereby transmitting the rotation of the drive source to the first and second rotating members. Note that an optical device including the light amount control device also constitutes another aspect of the present invention. Effect of the Invention

[0007] According to the present invention, it is possible to control the amount of light while obtaining good bokeh with a single drive source for two optical systems. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing a configuration of an imaging apparatus according to an embodiment. [Diagram 2] FIG. 2 is a front perspective view showing the light amount control device according to the embodiment. [Diagram 3] FIG. 2 is a rear perspective view showing the light amount control device in the embodiment. [Figure 4] FIG. 2 is an exploded front perspective view showing the configuration of the light amount control device in the embodiment. [Diagram 5] FIG. 2 is an exploded perspective view showing the configuration of the light amount control device according to the embodiment; [Figure 6] 5A to 5C are diagrams for explaining the operation of the light amount control device in the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0010] 1 shows the configuration of an imaging device 10 as an optical device equipped with a light amount control device of the embodiment. The imaging device 10 has a camera body 1 and a stereo optical unit 20 provided in the camera body 1. The stereo optical unit 20 includes a first optical unit 2 and a second optical unit 3. Note that, although the stereo optical unit 20 is fixed integrally to the camera body 1 in this embodiment, the stereo optical unit 20 may be an interchangeable lens (optical device) that is detachable from the camera body 1.

[0011] The first optical unit 2 has a first optical system 201, a lens control unit 204, and a lens communication unit 205. The second optical unit 3 has 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 are driven in 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, and may include optical elements other than lenses, such as a prism or a mirror. Furthermore, 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 in response to shaking of the imaging device 10 due to camera shake or the like to reduce (correct) image blur.

[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 has a first diaphragm provided for the first optical system 201, a second diaphragm provided for the second optical system 301, and a diaphragm motor 105 provided as a single drive source in common for the first and second diaphragms. The diaphragm motor 105 drives the first and second diaphragms, thereby changing the diameter of the diaphragm opening formed by the first and second diaphragms, and the light amount is controlled (adjusted).

[0013] 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. The lens control unit 204 also controls the aperture motor 105 in response to an aperture command from the camera body 1 via the lens communication unit 205.

[0014] The camera body 1 has a first imaging element 12 that photoelectrically converts (captures) the subject image formed by the first optical system 201, and a second imaging element 13 that photoelectrically converts the subject image formed by the 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. The camera body 1 also has a camera control unit 14 that controls the driving of the first imaging element 12 and the second imaging element 13, and 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 also has 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, a camera body 1 is shown having two image sensors 12, 13 for the two optical systems 201, 301, but it is also possible to obtain image signals for generating the first and second image data in two areas on a single image sensor provided for the two optical systems.

[0015] Figures 2, 3, 4, and 5 show a specific configuration of the light amount control device 100. Also, Figure 6 shows the operation of the light amount control device 100. Note that Figure 6 shows the light amount control device 100 when viewed from the optical axis direction (the direction in which the central axes of the openings 101a and 101b extend) with a cam plate 103, which will be described later, removed.

[0016] The light amount control device 100 has a first diaphragm including a plurality of (six in this embodiment) blade members 104 for the first optical system 201, a second diaphragm including six blade members 104 for the second optical system 301, and an opening / closing mechanism (not shown) for opening and closing the blade members 104. The opening / closing mechanism has an diaphragm motor 105 as a drive source, an diaphragm base plate 101 as a base member, a stepped gear 107 as a relay gear, a first driving ring 120 as a first rotating member, a second driving ring 121 as a second rotating member, and a cam plate (cam member) 103 as a pressing member.

[0017] The aperture motor 105 is a stepping motor, and a pinion gear 106 serving as a drive gear is fixed to its rotary drive shaft 105a so as to be rotatable together with the motor. The rotary drive shaft 105a is rotatably held by a bearing 105b. A fixing portion 105c of the aperture motor 105 is fixed to the aperture base plate 101 by a screw, so that the rotary drive shaft 105a is disposed at a predetermined position relative to the aperture base plate 101. The pinion gear 106 protrudes from a hole 101e formed in the aperture base plate 101 toward the first and second drive rings.

[0018] The diaphragm base plate 101 is formed with a first opening 101a corresponding to the first optical system 201 and a second opening 101b corresponding to the second optical system 301. Fitting receiving portions 101c are formed at multiple locations in the circumferential direction on the inner circumference of the first opening 101a, and fitting portions 120a provided on the outer circumference of the first driving ring 120 are fitted into the multiple fitting receiving portions 101c. This allows the first driving ring 120 to be held rotatably around the central axis of the first opening 101a (i.e., around the optical axis OA1 of the first optical system 201) relative to the diaphragm base plate 101. Fitting receiving portions 101d are formed at multiple locations in the circumferential direction on the inner circumference of the second opening 101b, and fitting portions 121a provided on the outer circumference of the second driving ring 121 are fitted into the multiple fitting receiving portions 101d. As a result, the second drive ring 121 is held rotatably relative to the diaphragm base plate 101 around the central axis of the second aperture 101b (that is, around the optical axis OA2 of the second optical system 301).

[0019] The stepped gear 107 has a first gear portion 107b and a second gear portion 107c that is formed coaxially with the first gear portion 107b and has a smaller diameter and fewer teeth than the first gear portion 107b. A hole portion 107a is formed in the center of the stepped gear 107, and a support shaft portion 101f provided on the aperture base plate 101 is fitted into the hole portion 107a. As a result, the stepped gear 107 is rotatably held by the aperture base plate 101. A pinion gear 106 meshes with the first gear portion 107b.

[0020] Gear portions 120b, 121b are formed on parts of the outer periphery of the first driving ring 120 and the second driving ring 121, and the second gear portion 107c of the stepped gear 107 meshes with these gear portions 120b, 121b. Therefore, as shown in Fig. 6, when the aperture motor 105 is driven and the pinion gear 106 rotates, the first driving ring 120 and the second driving ring 121 rotate in the same direction relative to the aperture base plate 101 via the stepped gear 107. In Fig. 6, the pinion gear 106 rotates counterclockwise, the stepped gear 107 rotates clockwise, and the first driving ring 120 and the second driving ring 121 rotate counterclockwise.

[0021] In this embodiment, rotation is transmitted from the pinion gear (driving gear) 106 to the first and second driving rings 120, 121 via one stepped gear (intermediate gear) 107. Alternatively, two intermediate gears may be meshed with the driving gear, and the rotation may be transmitted to the first driving ring 120 via one intermediate gear, and to the second driving ring 121 via the other intermediate gear. Furthermore, an idler gear may be disposed between the driving gear and the intermediate gears.

[0022] The first diaphragm is an iris diaphragm in which six blade members 104 are arranged at equal intervals in the circumferential direction of the first drive ring 120 so that parts of the blade members 104 overlap with each other in the optical axis direction, forming a diaphragm aperture corresponding to the first optical system 201. Six rotation holes 120c are formed at equal intervals in the circumferential direction in the first drive ring 120. Rotation pins 104a of the six blade members 104 are rotatably fitted into the corresponding rotation holes 120c in the first drive ring 120. The second diaphragm is an iris diaphragm in which six blade members 104 are arranged at equal intervals in the circumferential direction of the second drive ring 121 so that parts of the blade members 104 overlap with each other in the optical axis direction, forming a diaphragm aperture corresponding to the second optical system 301. Six rotation holes 121c are formed at equal intervals in the circumferential direction in the second drive ring 121. Rotation pins 104a of the six blade members 104 are rotatably fitted into the corresponding rotation holes 121c in the second drive ring 121.

[0023] The first and second diaphragms are not limited to those having six blade members, but may be iris diaphragms having three or more blade members.

[0024] The cam plate 103 is disposed so as to sandwich the first driving ring 120, the second driving ring 121, and the twelve blade members 104 between the diaphragm base plate 101 and the cam plate 103, and is fixed to the diaphragm base plate 101 with screws. The cam plate 103 is formed with a first opening 103a corresponding to the first optical system 201 and a second opening 103b corresponding to the second optical system 301. Six cam groove portions 103c are formed around the first opening 103a in the cam plate 103 at equal intervals in the circumferential direction, and six cam groove portions 103d are formed around the second opening 103b at equal intervals in the circumferential direction. In the first diaphragm, the cam pins 104b of the six blade members 104 are engaged with the corresponding cam groove portions 103c. In the second diaphragm, the cam pins 104b of the six blade members 104 are engaged with the corresponding cam groove portions 103d.

[0025] With the above configuration, when each drive ring (120, 121) rotates, the rotating pin 104a of each blade member 104 moves in the circumferential direction together with each drive ring. At the same time, the cam pin 104b of each blade member 104 moves along each cam groove portion (103b, 103d) of the cam plate 103, so that each blade member 104 rotates (turns) in the opening and closing direction around the rotating pin 104a. This changes the diameter (aperture value) of the aperture opening formed by the six blade members 104 in each of the first and second apertures. The lens control unit 204 controls the driving direction of the aperture motor 105 (i.e., the direction of change in the aperture value) by changing the polarity of the driving pulse signal applied to the aperture motor 105, and controls the driving position of the aperture motor 105 (i.e., the aperture value) by counting the number of pulses of the driving pulse signal. A sensor may be provided to detect whether each aperture is in the open aperture state.

[0026] When driving the blade members via an arm or lever as in the light quantity control devices of Patent Documents 1 and 2, the amount of rotation of the arm or lever is generally limited to about 30° to 40°, making it difficult to precisely control the aperture diameter. In contrast, when driving the blade members via gears as in this embodiment, the amount of rotation of the gears can be set to 60° or more (even 360° or more), making it possible to precisely control the aperture diameter.

[0027] In each of the first and second apertures, the amount of overlap between the six blade members 104 changes depending on the rotational positions of the blade members 104, which changes the load on the aperture motor 105. Specifically, as the amount of overlap between the blade members 104 increases, the load on the aperture motor 105 increases. The lens control unit 204 controls the output torque of the aperture motor 105 by changing the pulse frequency of the drive pulse signal applied to the aperture motor 105.

[0028] In this embodiment, the stepped gear 107 is held in a portion between the first opening 101a and the second opening 101b of the diaphragm base plate 101 as viewed in the optical axis direction shown in Fig. 6. This makes it possible to hold the stepped gear 107 so as not to significantly protrude upward from the first and second diaphragms (the first and second driving rings 120, 121), and to suppress an increase in the height of the light amount control device 100.

[0029] Furthermore, the stepped gear 107 is held at a position where the distances D1 and D2 from the rotation central axis (center of the support shaft 101f) of the stepped gear 107 to the respective centers (positions of the optical axes OA1 and OA2) of the first opening 101a and the second opening 101b of the diaphragm base plate 101 in the optical axis direction shown in Fig. 6 are equal to each other. However, the distances D1 and D2 do not have to be strictly the same, and one may have a difference of 10% or less with respect to the other. In other words, it is sufficient that the ratio of the distances D1 and D2 is 0.9 or more and 1.1 or less.

[0030] By arranging the stepped gear 107 in this manner, the second gear portion 107b can be meshed with the gear portions 120b, 121b of the first and second driving rings 120, 121 at the same reduction ratio. This makes it possible to control the rotation directions and rotation amounts of the first and second driving rings 120, 121 to be the same (or to be considered to be the same) by driving the single aperture motor 105. As a result, the first aperture and the second aperture can always be set to the same (or to be considered to be the same) aperture value, and the brightness of the first and second optical systems 201, 301 can be matched to each other.

[0031] In addition, the upper limit of the number of teeth of the gear portions 120b, 121b provided on the first and second driving rings 120, 121 cannot be set to be greater than the distance between the rotation central axes of the first and second driving rings 120, 121. On the other hand, since the pinion gear 106 is fixed to the outer periphery of the rotary driving shaft 105a of the aperture motor 105, the lower limit of the number of teeth cannot be made sufficiently small. For this reason, unless the relay gear 107 is provided, the reduction ratio from the pinion gear 106 to the first and second driving rings 120, 121 cannot be set to a large value.

[0032] In order to control the amount of light with high precision, it is necessary to reduce the sensitivity of the light amount control by reducing the amount of rotation of the first and second drive rings 120, 121 relative to the amount of rotation of the aperture motor 105. By providing the relay gear 107 between the pinion gear 106 and the first and second drive rings 120, 121 as in this embodiment, it is possible to set a large reduction ratio from the pinion gear 106 to the first and second drive rings 120, 121. As a result, it is possible to reduce the ratio of the amount of rotation of the first and second drive rings 120, 121 relative to the amount of rotation of the aperture motor 105, enabling high-precision light amount control.

[0033] Furthermore, by providing the stepped gear 107, the degree of freedom in the arrangement of the aperture motor 105 when viewed in the optical axis direction is increased. That is, instead of arranging the aperture motor 105 directly above the stepped gear 107 as shown in FIG. 4, it is also possible to arrange it diagonally above the stepped gear 107. This makes it possible to change the external shape of the light amount control device 100 depending on the arrangement space of the light amount control device 100 within the stereo optical unit 20.

[0034] Furthermore, by using the same part for the first drive ring 120 and the second drive ring 121, it is possible to suppress the difference in aperture value between the first and second apertures that may arise due to variations in manufacturing errors when these are made into separate parts.

[0035] In this embodiment, the aperture corresponding to each aperture value from maximum aperture to minimum aperture can be made into a polygonal shape close to a circle by using the six blade members 104. Therefore, a good blur effect can be obtained in imaging.

[0036] In this embodiment, the first and second drive rings (rotating members) 120 and 121 are formed with rotation holes 120c and 121c into which the rotation pin 104a of the blade member 104 fits, and the cam grooves 103c and 103d into which the cam pin 104b engages are formed on the cam plate (pressing member) 103. Alternatively, the rotating members may be formed with cam grooves into which the cam pins of the blade members engage, and the pressing member may be formed with rotation holes into which the rotation pins of the blade members fit. Alternatively, the aperture base plate (base member) may be formed with rotation holes into which the rotation pins of the blade members fit, and the rotating members may be formed with cam grooves into which the cam pins of the blade members engage.

[0037] Furthermore, instead of the cam plate in this embodiment, a first cam plate (first cam member) having a first opening corresponding to the first optical system 201, and a second cam plate (second cam member) having a second opening corresponding to the second optical system 301 may be provided. In this case, it is preferable to make the first cam plate and the second cam plate the same part. This makes it possible to suppress the difference in aperture value between the first and second apertures caused by variations in manufacturing error of the cam groove portions of the first and second cam plates, respectively.

[0038] The above embodiment includes the following configurations.

[0039] (Configuration 1) A light amount control device that controls a light amount in a first optical system and a second optical system that are arranged in parallel, A single drive source; a base member that holds the drive source and has a first opening corresponding to the first optical system and a second opening corresponding to the second optical system; a first diaphragm forming an aperture for light passing through the first opening; a second diaphragm forming a diaphragm opening for light passing through the second opening; a first rotating member that rotates about a central axis of the first opening relative to the base member; a second rotating member that rotates about a central axis of the second opening relative to the base member, each of the first diaphragm and the second diaphragm is an iris diaphragm having three or more blade members; The first and second rotary members rotate to operate the first and second apertures, A light quantity control device characterized in that a drive gear rotated by the drive source meshes with an intermediate gear, and the intermediate gear meshes with gear portions provided on the first and second rotating members, thereby transmitting the rotation of the drive source to the first and second rotating members. (Configuration 2) The light amount control device described in configuration 1, characterized in that the relay gear is held between the first opening and the second opening in the base member when viewed from the direction in which the central axis extends. (Configuration 3) The light amount control device described in configuration 1 or 2, characterized in that the relay gear is held by the base member at a position where the ratio of the distance from the rotational center axis of the relay gear to the center axis of the first opening when viewed from the direction in which the center axis extends to the distance from the rotational center axis to the center axis of the second opening is 0.9 or more and 1.1 or less. (Configuration 4) 4. The light amount control device according to any one of configurations 1 to 3, wherein the first and second rotating members rotate in the same direction as each other due to the rotation of the drive source. (Configuration 5) A light quantity control device as described in any one of configurations 1 to 4, characterized in that the reduction ratio from the drive gear to the gear portion of the first rotating member via the relay gear and the reduction ratio from the drive gear to the gear portion of the second rotating member via the relay gear are the same. (Configuration 6) 6. The light amount control device according to any one of configurations 1 to 5, wherein the first rotating member and the second rotating member are configured from the same part. (Configuration 7) A light quantity control device as described in any one of configurations 1 to 6, characterized in having a cam member formed with a cam that rotates the blade members in the first and second apertures in an opening and closing direction in response to rotation of the first and second rotating members. (Configuration 8) the cam member includes a first cam member on which the cam that rotates the blade member of the first diaphragm is formed, and a second cam member on which the cam that rotates the blade member of the second diaphragm is formed, 8. The light amount control device according to configuration 7, wherein the first cam member and the second cam member are configured from the same part. (Configuration 9) A light quantity control device described in any one of configurations 1 to 8, characterized in that the first and second rotating members have cams that rotate the blade members in the first and second apertures in opening and closing directions in response to their rotation. (Configuration 10) A light amount control device according to any one of configurations 1 to 9; An optical device comprising the first optical system and the second optical system.

[0040] The embodiments described above are merely representative examples, and various modifications and alterations are possible for each embodiment when implementing the present invention. [Explanation of symbols]

[0041] 20 Stereo Optical Unit 100 Light quantity control device 101 Squeezed base plate 103 Cam plate 104 Blade member 105 Aperture motor 106 Pinion Gear 107 gears 120 First driving ring 121 Second driving ring 130 First cam plate 131 Second cam plate

Claims

1. A single drive source including a rotating shaft on which a drive gear is provided, A base member that holds the drive source and is provided with a first opening and a second opening, A first aperture including three or more vane members corresponding to the light passing through the first opening, A second aperture including three or more vane members corresponding to the light passing through the second aperture, A first rotating member that moves the three or more vane members of the first aperture by rotating, A second rotating member that moves the three or more vane members of the second aperture by rotating, It has an intermediate gear that meshes with the aforementioned drive gear, A drive device characterized in that each of the first rotating member and the second rotating member includes a gear portion that meshes with the intermediate gear.

2. The drive device according to claim 1, characterized in that the relay gear is arranged between the first opening and the second opening in the base member.

3. The drive device according to claim 1, characterized in that the intermediate gear is arranged such that the ratio of the distance from the rotation axis of the intermediate gear to the central axis of the first opening to the distance from the rotation axis to the central axis of the second opening is 0.9 or more and 1.1 or less.

4. The drive device according to claim 1, characterized in that the first rotating member and the second rotating member rotate in the same direction as a result of the rotation of the drive gear.

5. The drive device according to claim 1, characterized in that the reduction ratio of the rotation of the first rotating member to the rotation of the drive gear and the reduction ratio of the rotation of the second rotating member to the rotation of the drive gear are the same.

6. The drive device according to claim 1, characterized in that the first rotating member and the second rotating member have the same configuration as each other.

7. The drive device according to claim 1, further comprising a cam member having a cam groove formed therein, which engages with the three or more vane members provided on each of the first aperture and the second aperture.

8. The drive device according to claim 7, characterized in that the cam member includes a first cam member corresponding to the first aperture and a second cam member corresponding to the second aperture.

9. The drive device according to claim 8, characterized in that the first cam member and the second cam member have the same configuration as each other.

10. The drive device according to claim 1, characterized in that the first rotating member and the second rotating member are provided with cam grooves into which cam pins provided on the three or more vane members of the first aperture and the second aperture engage.

11. A drive device according to any one of claims 1 to 10, An optical instrument characterized by having a first optical system corresponding to the first aperture and a second optical system corresponding to the second aperture.

Images