Light-shielding unit and lens barrel equipped with the same

Abstract

To provide a light-shielding unit that can reduce the bending-up of a movable blade while smoothly operating the movable blade, and a lens barrel including the light-shielding unit.SOLUTION: An aperture unit 20 includes a bottom board 21, a cover 25, and a plurality of aperture blades 23. The plurality of aperture blades 23 are located between the bottom board 21 and the cover 25 and change the size of an opening 23e to adjust the amount of light passing through the opening. The plurality of movable blades include: the aperture blades 23 each including a boss 23b at its first end and a free edge at its second end opposite to the boss 23b, and aperture blades 123 each including a boss 123b at its first end and a revolving portion 123d at its second end opposite to the boss 123b and revolving along a gap between the bottom board 21 and the cover 25.SELECTED DRAWING: Figure 21B

Description

Technical Field

[0001] The present disclosure relates to a light-shielding unit and a lens barrel including the same.

Background Art

[0002] An imaging device such as a camera is provided with a plurality of lens groups, a diaphragm that adjusts the area of an aperture through which light passes, a shutter unit, and the like. For example, Patent Document 1 discloses a vane drive device that includes a plurality of vanes annularly arranged around a light passing path and a drive ring that rotates these plurality of vanes in order to reduce the warping of the vane group. Each of the plurality of vanes has an engaging portion that engages with a cam groove provided in the drive ring, and at least a part of the cam groove is provided so as to incline toward the radially outer side of the drive ring.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide a light-shielding unit capable of suppressing warping of a movable vane while smoothly operating the movable vane, and a lens barrel including the same.

Means for Solving the Problems

[0005] The light-shielding unit according to the present disclosure includes a first frame body, a second frame body, and a plurality of movable vanes. The first frame body has a first opening through which light passes. The second frame body has a second opening through which light passes. The plurality of movable vanes are disposed between the first frame body and the second frame body, form a third opening through which the light passing through the first opening passes, and adjust the amount of light passing through by changing the size of the third opening. The plurality of movable vanes include a first main shaft or a first main hole provided on the first end side, a first vane having a free end provided on the second end side opposite to the first main shaft or the first main hole, a second main shaft or a second main hole provided on the first end side, and a rotating portion provided on the second end side opposite to the second main shaft or the second main hole and rotating along the gap between the first frame body and the second frame body.

Effect of the Invention

[0006] According to the light-shielding unit of the present disclosure, it is possible to suppress the warping of the movable vanes while operating the movable vanes smoothly.

Brief Description of the Drawings

[0007]

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Mode for Carrying Out the Invention

[0008] (Findings etc. on which the present disclosure is based) The conventional vane drive device has the following problems. That is, in the device disclosed in the above publication, some of the cam grooves are provided so as to incline toward the radially outer side of the drive ring. For this reason, when the vane is driven, the boss running in the cam groove is likely to get caught, and there is a risk of malfunction of the vane.

[0009] Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, a more detailed description may be omitted as necessary. For example, detailed descriptions of well-known matters and duplicate descriptions of substantially the same configuration may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art. The applicant provides the accompanying drawings and the following description for those skilled in the art to fully understand the present disclosure, and does not intend to limit the subject matter described in the claims thereby.

[0010] The “subject side”, “image plane side”, and “light incident direction” described in the text are shown in FIGS. 1 and 2. The “image plane side” and “the side opposite to the subject side” are the same side. (Embodiment 1) The lens barrel 10 including the aperture unit (light shielding unit) 20 according to an embodiment of the present disclosure will be described as follows with reference to FIGS. 1 to 20.

[0011] Here, the lens barrel 10 of the present embodiment is provided with a configuration for suppressing the upward warping of the aperture blades (movable blades) 23 that occurs when the aperture blades (light-shielding unit) 20 are closed (the aperture diameter is reduced). Specific configurations thereof will be described below. Note that the direction of the upward warping of the aperture blades 23 means the direction in which the tip sides of the plurality of aperture blades 23 overlap (are braided) and bulge when the aperture blades 23 are rotated in the direction of reducing the aperture diameter. In the present embodiment, as shown in Fig. 17(a) and the like, it means the direction on the image plane side. (1) Configuration of the lens barrel 10 The lens barrel 10 according to the present embodiment is an interchangeable lens barrel that is attached to a camera body (not shown). As shown in Fig. 1, it includes an outer frame 11, an inner frame 12, an actuator 13, a guide pole 14, a fourth lens frame 15, a mount 16, first to fifth lenses L1 to L5, and an aperture unit 20. X is the optical axis defined by the first to fifth lenses L1 to L5.

[0012] The outer frame 11 is a substantially cylindrical member that constitutes the outer shell of the lens barrel 10 and encloses each component such as the first to fifth lenses L1 to L5. The inner frame 12 is disposed on the inner peripheral surface side of the outer frame 11 and holds the first lens L1 on the most upstream side in the light incident direction, the second lens L2 on its downstream side, and the third lens L3 on its downstream side. Further, the inner frame 12 holds the actuator 13 and the guide pole 14 substantially laterally of the third lens L3, the fourth lens frame 15 that is held on the guide pole 14 so as to be movable in the direction of the optical axis X on the downstream side of the third lens L3, the aperture unit 20 on its downstream side, and the fifth lens L5 on its downstream side.

[0013] The actuator 13 is a focus motor driven for focusing and is held by the inner frame 12. When the actuator 13 is powered from an electric circuit (not shown), it moves the fourth lens frame 15 holding the fourth lens (focus lens) L4 back and forth in the optical axis X direction along the guide pole 14. The guide pole 14 is a rod-shaped member that guides the fourth lens frame 15 driven by the actuator 13 back and forth in the optical axis X direction. The guide pole 14 is held by the inner frame 12 and is arranged parallel to the optical axis X direction.

[0014] The fourth lens frame 15 is included in the lens group that constitutes the optical system of the lens barrel 10, and holds the fourth lens L4 that moves in the optical axis X direction to adjust the focus of the light beam incident on the lens, that is, for focusing, and is driven by the actuator 13. Alternatively, the fourth lens frame 15 holds the fourth lens L4 that moves in the optical axis X direction to adjust the focal length of the light beam incident on the lens, that is, for zooming, and is driven in conjunction with the zoom operation. That is, the fourth lens frame 15 is movable in the optical axis direction for focusing and zooming.

[0015] The mount 16 is a portion that is attached to a camera body (not shown), is held by the outer frame 11, and is arranged on the most downstream side in the light incident direction within the lens barrel 10. As shown in FIG. 1, the first lens L1 to the fifth lens L5 are an optical system that guides light in the optical axis X direction, and are arranged in order from the subject side to the image plane side in the light incident direction. The first lens L1 is arranged on the most subject side among the lens group included in the lens barrel 10.

[0016] The second lens L2 is arranged at a position close to the surface on the image plane side (opposite to the subject side) of the first lens L1 inside the inner frame 12. The third lens L3 is arranged at a position inside the inner frame 12 and separated from the second lens L2 by a predetermined distance toward the image plane side. The fourth lens L4 is a focus lens provided inside the inner frame 12, and is movable back and forth in the optical axis X direction by an actuator 13 and is held by a fourth lens frame 15.

[0017] The fifth lens L5 is on the downstream side of the aperture unit 20 in the optical axis X direction and is arranged closest to the image plane side among the lens groups included in the lens barrel 10. The aperture unit 20 is arranged between the fourth lens L4 and the fifth lens L5 inside the inner frame 12, and adjusts the area or aperture diameter and the diameter through which the light transmitted through the first lens L1 to the fourth lens L4 passes, and adjusts the amount of light incident on the imaging element provided on the camera body side. The detailed configuration of the aperture unit 20 will be described in detail later. (2) Configuration of the aperture unit 20 In the lens barrel 10 of the present embodiment, as shown in FIG. 1, the first lens L1 to the fourth lens are arranged on the subject side of the aperture unit 20 in the optical axis X direction.

[0018] The aperture unit 20 is arranged on the downstream side of the fourth lens L4 that functions as a focus lens, as shown in FIG. 1. And, as shown in FIG. 2, the aperture unit 20 has a base plate (first frame body) 21, a drive ring 22, a plurality of aperture blades (movable blades) 23, a sheet member 24, a cover (second frame body) 25, a mounting screw 26, a fixed aperture sheet (fixed aperture member) 27, a drive motor 28, a photo interrupter 29a, and an FPC 29b. Further, as shown in FIG. 3, the aperture unit 20 adjusts the amount of light passing through the openings 21b, 22b, 23e, 24b, 25b, 27b formed at the centers of the substantially annular members by opening and closing the plurality of aperture blades 23 driven by the drive motor 28. The centers of the respective openings 21b, 22b, 23e, 24b, 25b, 27b and the opening of the aperture unit 20 are configured to substantially pass through the optical axis X.

[0019] When the aperture unit 20 closes the plurality of aperture blades 23 to the maximum extent, as shown in FIGS. 4A and 4B, the aperture diameter (area) of the aperture 23e formed by the plurality of aperture blades 23 becomes the minimum state. At this time, as shown in FIG. 4A, when viewed from the side opposite to the subject side, that is, the image plane side, a part of the tip side of the plurality of aperture blades 23 overlaps with each other in the circumferential direction centered on the optical axis X and is woven together, that is, they are arranged in a warped state.

[0020] Also, when the plurality of aperture blades 23 are rotated from the state shown in FIGS. 4A and 4B, as shown in FIGS. 5A and 5B, the aperture diameter (area) of the aperture 23e formed by the plurality of aperture blades 23 gradually increases. Furthermore, when the plurality of aperture blades 23 are further rotated from the state shown in FIGS. 5A and 5B, as shown in FIGS. 6A and 6B, the entire plurality of aperture blades 23 enter the gap between the base plate 21, the cover 25, etc., and the aperture diameter (area) of the aperture 23e formed by the plurality of aperture blades 23 becomes the maximum.

[0021] Note that in the state where the aperture diameter or aperture area of the aperture 23e shown in FIGS. 6A and 6B is the maximum, the size of the aperture portion of the aperture unit 20 is defined by a fixed aperture sheet 27 described later. That is, the aperture 27b of the fixed aperture sheet 27 is smaller than the aperture 23e of the aperture blades 23 with the maximum aperture diameter or aperture area and is constant. As described above, the aperture unit 20 of the present embodiment can adjust the amount of light passing through the aperture portion by rotating the plurality of aperture blades 23 between the closed state shown in FIGS. 4A and 4B and the open state shown in FIGS. 6A and 6B.

[0022] The floor (first frame body) 21 is a substantially annular member disposed on the most subject side in the light incident direction as shown in FIG. 2, and includes a substantially annular main body portion 21a, an opening (first opening) 21b formed in the central portion of the main body portion 21a to allow the light incident from the subject side to pass through, a wall portion (first wall portion) 21c (see FIG. 19), a radial regulation portion 21d (see FIGS. 16A, 17A, and 19), a first optical axis direction regulation portion 21e (see FIG. 19), and a second optical axis direction regulation portion 21f (see FIGS. 16A, 17A, and 19). As shown in FIG. 2, between the floor 21 and the fixed aperture sheet 27 disposed on the most downstream side in the light incident direction, a drive ring 22, a plurality of aperture blades 23, a sheet member 24, and a cover 25 are sequentially arranged from the subject side.

[0023] Also, on the subject side surface of the floor 21, as shown in FIGS. 3 and 7, in order to apply a driving force for opening and closing the plurality of aperture blades 23, a driving motor 28 and the like, which will be described later and are fixed to the floor 21, are arranged. The drive ring 22 is a substantially annular member disposed between the floor 21 and the aperture blades 23 in the light incident direction as shown in FIGS. 2 and 7.

[0024] More specifically, as shown in FIG. 8, the drive ring 22 includes a substantially annular main body portion 22a, an opening 22b formed at its center, a plurality of protruding portions (support portions, first support portions) 22c, a gear portion 22d, a light shielding portion 22e, a radial regulation portion 22f (see FIGS. 8, 16A, and 17A), a first optical axis direction regulation portion 22g (see FIG. 8), and a second optical axis direction regulation portion 22h (see FIGS. 14, 16A, and 17A). The drive ring 22 is rotationally driven by a drive motor 28 described later to rotate the plurality of aperture blades 23. More specifically, when the driving force from the drive motor 28 described later is transmitted via the gear 28a, the radial position of the radial regulation portion 22f of the drive ring 22 is regulated by the radial regulation portion 21d of the floor 21. Further, the first optical axis direction regulation portion 22g of the drive ring 22 abuts on the first optical axis direction regulation portion 21e of the floor 21, and the second optical axis direction regulation portion 22h of the drive ring 22 abuts on the second optical axis direction regulation portion 21f of the floor 21.

[0025] As a result, the drive ring 22 is sandwiched between the two optical axis direction restricting portions 21e and 21f of the floor 21, and thus rotates about the approximate optical axis X while its position in the optical axis direction is restricted. As a result, the drive ring 22 rotates a plurality of aperture vanes 23 to adjust the amount of light passing through the aperture portion between the state where the aperture vanes 23 are closed and the open state, that is, between the minimum diameter and the maximum diameter.

[0026] As shown in FIG. 8, the main body portion 22a is a substantially annular plate-like member, and an opening 22b is formed at the center thereof. The opening 22b is an opening portion through which the light of the aperture unit 20 passes, and has a diameter or area substantially equal to or slightly larger than that of the opening 23e formed when the plurality of aperture vanes 23 are fully opened. The opening 22b has a diameter or area substantially equal to or larger than that of the opening 27b of a fixed aperture sheet 27 described later.

[0027] As shown in FIGS. 8, 16a, 16b, 17a, and 17b, the protruding portions 22c are arranged at substantially equal angular intervals in the circumferential direction so as to protrude annularly from the surface of the main body portion 22a on the side opposite to the warping direction of the aperture vanes, that is, the side opposite to the subject side (cover 25 side), i.e., the image plane side, in this embodiment. The protruding portions 22c contact a part of the aperture vanes 23 in the annular portion and support the aperture vanes 23 from the subject side. A through hole is formed substantially at the center of the annularly protruding portion of the protruding portion 22c, and a boss 23b (first main axis) of the aperture vane 23 described later is inserted therein.

[0028] The protruding portion 22c (first support portion) has a convex shape protruding from the surface of the drive ring 22 in the warping direction of the aperture vanes 23, and supports the vicinity of the boss 23b (first main axis) of the aperture vanes 23. The protruding portion 22c preferably has a substantially arc, substantially ellipse, substantially parabola, substantially polynomial curve, or smooth curve shape in a cross-sectional view including the central axis of the through hole or the boss 23c (first main axis).

[0029] With these configurations, the aperture blade 23 can move smoothly and easily without an increase in driving load due to wear or snagging, and at the same time, it is possible to efficiently suppress the upward warping caused by the weaving of the aperture blades. The gear portion 22d is formed on a part of the outer peripheral surface of the main body portion 22a so as to mesh with a gear 28a (see FIGS. 2 and 14) attached to the rotating shaft of the drive motor 28. Then, when the rotational driving force of the drive motor 28 is transmitted through the gear 28a, the gear portion 22d rotationally drives the drive ring 22 about the optical axis X.

[0030] The light-shielding portion 22e is formed so as to project radially outward from a part of the outer peripheral surface of the main body portion 22a. Then, when the drive ring 22 is rotationally driven to a predetermined position during the opening and closing operation of the aperture blade 23 described later, the light-shielding portion 22e is inserted between the light-emitting portion and the light-receiving portion of the photointerrupter 29a to block the light irradiated from the light-emitting portion toward the light-receiving portion (see FIG. 14). Thereby, information on the rotational position of the drive ring 22 is detected by the photointerrupter 29a.

[0031] As shown in FIG. 2, the plurality of aperture blades (movable blades) 23 are arranged on the downstream side of the drive ring 22 in the light incident direction. Then, between the drive ring 22 and the sheet member 24, the plurality of aperture blades 23 rotate about a boss 23b (first main shaft) (see FIG. 10) to change the size (area) of the opening 23e (see FIGS. 4A, etc.) and adjust the amount of light passing through the opening portion of the aperture unit 20.

[0032] More specifically, as shown in FIG. 9, the aperture blade 23 has a main body portion 23a, a boss 23b (first main shaft), a boss 23c (first sub-shaft), and a tip portion (free end) 23d. As shown in FIG. 9, the main body portion 23a is a plate-like member formed in a blade shape and is molded from a high-rigidity resin such as LCP (Liquid Crystal Polymer), PPS (polyphenylene sulfide), or PA (polyamide).

[0033] As a result, since the aperture blade 23 is formed using a material with relatively high rigidity, the amount of upward warping described later can be suppressed. The boss 23b (first main shaft) is provided so as to protrude from the upper surface (the surface facing the drive ring 22) on one end (first end) side of the main body portion 23a as the rotation axis when the plurality of aperture blades 23 rotate. And the boss 23b (first main shaft) is inserted into the through hole formed in the central portion of the protruding portion 22c of the drive ring 22 described above. For this reason, in the opening and closing operation of the aperture blade 23 described later, when the drive ring 22 is rotationally driven, the boss 23b (first main shaft) moves in the circumferential direction accordingly.

[0034] The boss 23c (first sub - shaft) is provided so as to protrude from the surface (the surface facing the cover 25) of the main body portion 23a on the side opposite to the boss 23b (first main shaft). And the boss 23c (first sub - shaft) is inserted into a cam groove 25c (see FIG. 10) formed in the cover 25 described later. For this reason, in the opening and closing operation of the aperture blade 23 described later, when the drive ring 22 is rotationally driven and the aperture blade 23 moves in the circumferential direction, the boss 23c (first sub - shaft) moves while being guided by the cam groove 25c. Thereby, by changing the amount of rotation of the aperture blade 23 according to the amount of rotation of the drive ring 22, the area of the opening 23e formed by the plurality of aperture blades 23 can be changed, and the amount of light passing through the opening portion of the aperture unit 20 can be adjusted. When the drive ring 22 is rotationally driven, the relative positions of the boss 23b (first main shaft) and the boss 23c (first sub - shaft) with respect to the base plate 21 or the cover 25 change, the aperture blade 23 rotates around the boss 23b (first main shaft), and the size of the opening of the aperture unit 20 changes.

[0035] The tip portion 23d is a free end provided on the other end (second end) side of the main body portion 23a. When the aperture blade 23 rotates around the boss 23b (first main shaft), the tip portion 23d advances into the opening portion to cover the opening portion of the aperture unit 20 or retracts from the opening portion. Regarding the configuration of the plurality of aperture vanes 23 and the opening / closing mechanism for rotating them, details will be described later. In this embodiment, for example, 11 aperture vanes 23 are provided.

[0036] As shown in FIG. 2, the sheet member 24 is a substantially annular member disposed on the downstream side of the plurality of aperture vanes 23 in the light incident direction, and has a substantially annular main body portion 24a and an opening 24b formed in the central portion thereof. And the sheet member 24 has a through groove 24c having the same shape in a portion overlapping with a cam groove 25c (see FIG. 10) formed in a cover 25 disposed on the downstream side in the light incident direction.

[0037] As shown in FIG. 2, the cover (second frame body) 25 is a substantially annular member disposed on the downstream side of the sheet member 24 in the light incident direction, and as shown in FIG. 10, has a substantially annular main body portion 25a, an opening 25b, a cam groove 25c, a wall portion (second wall portion) 25d, and a protruding portion (support portion, second support portion) 25e. As shown in FIG. 10, the main body portion 25a is a substantially annular plate-like member, and an opening 25b is formed at the center thereof.

[0038] The opening 25b is an opening portion through which the light of the aperture unit 20 passes, and has an area equivalent to or slightly larger than that of the opening 23e formed when the plurality of aperture vanes 23 are in the fully open state. The cam groove 25c is a guide groove formed in the main body portion 25a, into which the boss 23c (first sub-axis) of the above-described aperture vane 23 is inserted. For this reason, the cam groove 25c is formed in the same number (11 in this embodiment) as the aperture vanes 23. And when the drive ring 22 is rotationally driven and the aperture vanes 23 move in the circumferential direction, the boss 23c (first sub-axis) moves along the cam groove 25c, whereby the plurality of aperture vanes 23 are respectively rotated.

[0039] FIG. 11 shows a state in which only one aperture blade 23 is arranged with the boss 23c (first sub-shaft) inserted into the cam groove 25c, and FIG. 12 shows a state of FIG. 11 viewed from the AA direction in the drawing. For convenience of explanation, in FIG. 11, the illustration of the sheet member 24 is omitted. In this state, as shown in FIG. 13 which is an enlarged view of part B in FIG. 12, the boss 23c (first sub-shaft) is inserted into the cam groove 25c and moves along the cam groove 25c as the drive ring 22 rotates.

[0040] The wall portion 25d is a wall-shaped member arranged to cover a part of the outer peripheral portion of the main body portion 25a, and constitutes an oil intrusion prevention structure (see FIG. 20 etc.) described later. The protruding portion 25e is an annular portion arranged on the inner peripheral side portion of the upper surface of the main body portion 25a (the surface facing the aperture blade 23 and the sheet member 24), and is formed to protrude from the upper surface of the main body portion 25a. Further, the annular protruding portion 25e is arranged substantially concentrically with the opening 25b. And the protruding portion 25e abuts on a part of the aperture blade 23 and supports the aperture blade 23 from the side opposite to the subject side.

[0041] More specifically, as shown in FIG. 11, the protruding portion 25e is arranged at a position closer to the boss 23b (first main shaft) which is the rotation axis of the aperture blade 23 arranged on the cover 25. And the protruding portion 25e supports the aperture blade 23 at a position closer to the boss 23b (first main shaft) of the aperture blade 23. Also, in the open state where the plurality of aperture blades 23 are accommodated in the gap between the floor 21 and the cover 25, the protruding portion 25e is arranged at a position where the three aperture blades 23 overlap.

[0042] On the other hand, since the protruding portion 22c on the drive ring 22 side is provided near the rotation axis (boss 23b (first main shaft)) of each aperture blade 23, it is arranged at a position overlapping one aperture blade 23 regardless of the rotation positions of the plurality of aperture blades 23. Therefore, the protruding portion 25e is formed to have a lower protruding height than the protruding portion 22c so that the three aperture blades 23 can move easily.

[0043] The protruding portion 25e (second support portion) is formed on the cover (second frame body) 25 and is located in the vicinity of the opening of the diaphragm unit 20 or the opening 25b (second opening) of the cover (second frame body) 25. Further, the protruding portion 25e (second support portion) is disposed outside the opening 27b of the fixed aperture sheet 27 that determines the aperture diameter or aperture area of the diaphragm unit 20 in the fully open state of the diaphragm blades 23, that is, on the side away from the opening center.

[0044] Furthermore, the protruding portion 25e (second support portion) is located closer to the central axis of the opening of the diaphragm unit 20 or the opening 25b (second opening) of the cover (second frame body) 25 than the protruding portion 22c (first support portion) of the drive ring 22, and is provided so as to contact the surface on the same side as the upward warping direction of the diaphragm blades 23. Furthermore, the protruding portion 25e (second support portion) is provided annularly with respect to the central axis of the opening of the diaphragm unit 20 or the opening 25b (second opening) of the cover (second frame body) 25.

[0045] Furthermore, the protruding portion 25e (second support portion) preferably has a substantially arc, or substantially elliptical, or substantially parabolic, or substantially polynomial curve, or a gentle curve shape in a cross-sectional view including the central axis of the opening of the diaphragm unit 20 or the opening 25b (second opening) of the cover (second frame body) 25. With these configurations, the diaphragm blades 23 can move smoothly and easily without increasing the driving load due to wear or snagging, and at the same time, the upward warping due to the weaving of the diaphragm blades can be efficiently suppressed.

[0046] As shown in FIG. 2, three mounting screws 26 are provided to fix the cover 25 to the floor 21 from the downstream side of the cover 25 in the light incident direction, as shown in FIG. 4A and the like. The fixed aperture sheet (fixed aperture member) 27 is arranged on the downstream side of the cover 25, i.e., the most downstream side of the aperture unit 20, in the light incident direction as shown in FIG. 2. The fixed aperture sheet 27 has a substantially annular main body portion 27a and an aperture 27b formed in the central portion of the main body portion 27a, and is provided to define the diameter or area of the aperture portion when the aperture unit 20 is in the fully open state. Further, the fixed aperture sheet 27 is fixed to the surface of the cover 25 on the side opposite to the subject side.

[0047] The drive motor 28 is fixed to the base plate 21 by mounting screws 28b (see FIGS. 2, 4A, etc.) in order to apply a driving force to the plurality of aperture vanes 23 when performing the opening and closing operations of the plurality of aperture vanes 23. The drive motor 28 has an FPC 29b electrically connected thereto, and the rotating shaft rotates by power supply from an electric circuit (not shown). More specifically, the drive motor 28 rotates the drive ring 22 around the optical axis X through a gear portion 22d arranged to mesh with the gear 28a by rotating the gear 28a press-fitted into the rotating shaft.

[0048] The photo interrupter 29a has a light emitting portion and a light receiving portion, and is provided to detect the rotational position of the drive ring 22. Then, as shown in FIG. 14, the photo interrupter 29a is attached to the upper surface (the surface on the subject side) of the cover 25. The FPC 29b is a flexible printed circuit board, and as shown in FIGS. 2 and 3, electrically connects the photo interrupter 29a and the drive motor 28, and is connected to an electric circuit (not shown) via a connector. Then, as shown in FIGS. 3 and 4, the FPC 29b is attached to the upper surface (the surface on the subject side) of the base plate 21.

[0049] <Opening and closing mechanism of the aperture vane 23> Here, the mechanism for opening and closing the 11 aperture vanes 23 in the aperture unit 20 of the present embodiment is as follows. That is, as described above, the aperture unit 20 of the present embodiment changes the area of the opening 23e formed in the central portion of the 11 aperture vanes 23 by rotating the 11 aperture vanes 23 around their respective bosses 23b (first main shafts).

[0050] Specifically, the bosses 23b (first main shafts) of the 11 respective aperture vanes 23 are respectively inserted into the through-holes at the centers of the protrusions 22c formed on the drive ring 22. On the other hand, the bosses 23c (first sub-shafts) of the aperture vanes 23 are respectively inserted into the cam grooves 25c formed in the cover 25 as shown in FIGS. 12 and 13. Here, when the boss 23c (first sub-shaft) is in the position shown in FIG. 13, as shown in FIGS. 6A and 6B, the aperture vane 23 is in the open state where the opening 23e is the largest. Then, as the boss 23c (first sub-shaft) moves rightward along the cam groove 25c shown in FIG. 13, the tip portion 23d of the aperture vane 23 rotates inward in the radial direction, and as shown in FIGS. 5A and 5B, the area of the opening 23e or the aperture diameter becomes smaller. And when the boss 23c (first sub-shaft) moves to near the right end of the cam groove 25c, as shown in FIGS. 4A and 4B, the aperture vane 23 shifts to the aperture state (closed state) where the opening 23e is the smallest.

[0051] Also, the drive ring 22 is rotationally driven around the optical axis X when the rotational driving force of the drive motor 28 is transmitted to the gear portion 22d via the gear 28a. The rotational position information of the drive ring 22 is detected when the light-shielding portion 22e integrally provided on the outer peripheral portion of the drive ring 22 passes through the photo interrupter 29a. Thereby, the aperture diameter or the opening area of the opening 23e of the aperture vane 23 can be adjusted.

[0052] As shown in Fig. 14, the aperture blade 23 has a boss 23c (the first sub-axis) inserted into the cam groove 25c of the cover 25 and a boss 23b (the first main axis) inserted into the through-hole of the drive ring 22. When the drive ring 22 is rotationally driven by the drive motor 28, the aperture blade 23 moves in the circumferential direction together with the drive ring 22 and rotates around the boss 23b (the first main axis) as the rotation axis in accordance with the movement of the boss 23c (the first sub-axis) along the cam groove 25c.

[0053] Thereby, it is possible to adjust so as to decrease or increase the area or the aperture diameter of the aperture 23e formed by the plurality of aperture blades 23. <Anti - warping structure of the aperture blade 23> As shown in Fig. 15A, the aperture unit 20 of the present embodiment is provided with an anti - warping structure to suppress the warping of the tip 23d of each aperture blade 23 toward the side where it is woven in when the plurality of aperture blades 23 are closed. The anti - warping structure will be described as follows with reference to Figs. 15A to 16B.

[0054] That is, as shown in Figs. 15A and 15B, as the plurality of aperture blades 23 reduce the aperture diameter, the woven part of the tip 23d of the aperture blade 23 bulges upward, and warping occurs toward the image plane side. At this time, when the aperture blade 23 is in such a warped state, for example, it may come into contact with the oppositely arranged lens L5 or the like, resulting in contact marks on the lens L5 or the like. Furthermore, due to the occurrence of warping, the center position of the aperture 23e formed by the plurality of aperture blades 23 is displaced, and the position on the optical axis X is displaced. As a result, the designed optical performance may not be exhibited.

[0055] Therefore, the aperture unit 20 of the present embodiment has an anti - warping structure for the plurality of aperture blades 23 with a simple configuration without increasing the number of parts. Specifically, as shown in FIGS. 16A and 16B, in order to suppress the warping during the weaving of the aperture blades 23, two protrusions 22c and 25e are arranged on the surfaces of the drive ring 22 and the cover 25 that face the aperture blades 23.

[0056] The protrusions 22c and 25e are respectively arranged on the drive ring 22 and the cover 25 so as to abut against a part of the aperture blades 23. And the protrusions 22c and 25e support the aperture blades 23 in the direction of suppressing the warping during the weaving of the aperture blades 23. As described above, 11 protrusions 22c, the same number as the aperture blades 23, are provided on the surface of the drive ring 22 that faces the aperture blades 23. And the protrusions 22c are arranged around all the holes into which the bosses 23b (first main shafts) of the 11 aperture blades 23 are inserted. As shown in FIG. 16A, the protrusions 22c support the vicinity of the root of the aperture blades 23 (near the bosses 23b) from the subject side.

[0057] As described above, the protrusion 25e is provided in an annular shape on the surface of the cover 25 that faces the aperture blades 23. And as shown in FIG. 16A, the protrusion 25e supports the portion near the center of the aperture blades 23 from the side opposite to the subject side. Thereby, in a state where the plurality of aperture blades 23 are closed (the aperture diameter is reduced), the aperture blades 23 abut against the respective protrusions 22c and 25e, and the deformation of the aperture blades 23 can be restricted.

[0058] Therefore, according to the configuration (solid line) of the aperture unit 20 of the present embodiment, compared with the position of the aperture blades in the configuration where the protrusions 22c and 25e shown by the broken line in FIG. 16B are not provided, the amount of warping of the aperture blades 23 downstream in the light incident direction can be effectively suppressed. As a result, it is possible to prevent the occurrence of problems caused by the tip 23d of the aperture blades 23 coming into contact with the lens L5 or the like arranged on the downstream side of the aperture unit 20 in the light incident direction.

[0059] Furthermore, in the aperture unit 20 of the present embodiment, as shown in FIG. 17A, a spacer portion 25f (a part of the cover 25) (see FIG. 20) is provided between the fixed aperture diameter of the aperture unit 20 defined by the fixed aperture sheet 27 and the aperture blades 23. That is, the fixed aperture sheet 27 that defines the fixed aperture diameter of the aperture unit 20 is arranged such that a part of the cover 25, the spacer portion 25f, is sandwiched between it and the aperture blades 23.

[0060] Here, as shown in FIG. 17A, the amount of warping upward of the aperture blades 23 increases in the downstream side in the light incident direction, that is, the weaving side, as the aperture blades 23 are rotated in the direction of closing the aperture. Therefore, the warped-up portion of the aperture blades 23 moves from the substantially open state shown in FIG. 17B and, as the aperture blades 23 are rotated in the direction of closing the aperture, as shown in FIG. 17A, beyond the extension line Y2 in the radial inner side of the protruding portion 25e (the second support portion) of the cover 25 and further to a position beyond the extension line Y1 in the radial inner side of the fixed aperture sheet 27 (fixed aperture diameter). At this time, the aperture blades 23 come into contact with the protruding portion 25e, and the position in the optical axis X direction is regulated.

[0061] In the aperture unit 20 of the present embodiment, as described above, when the plurality of aperture blades 23 are in the substantially open state shown in FIG. 17B, they are arranged on the upstream side in the light incident direction from the position of the fixed aperture diameter defined by the fixed aperture sheet 27. And when the aperture blades 23 are rotated in the direction of closing the aperture, as shown in FIG. 17A, the plurality of aperture blades 23 are configured such that the tip portions 23d warp upward to the downstream side in the light incident direction and cross over the position (extension line Y1) of the fixed aperture diameter.

[0062] As a result, from the state where the aperture 23e formed by the plurality of aperture blades 23 is maximized to the state where it is minimized (FIG. 17A), the aperture 23e of the aperture blades 23 can be arranged near the position of the extension line Y1 of the fixed aperture diameter defined by the fixed aperture sheet 27 in the light incident direction. When a plurality of aperture blades 23 move in a direction to reduce the size of the aperture 23e (third aperture), the plurality of aperture blades 23 are moved so as to cross a virtual plane that constitutes the aperture 27b formed by the fixed aperture sheet 27 (fixed aperture member) in the same direction as the warping-up direction as the warping-up amount increases.

[0063] When the plurality of aperture blades 23 are in the fully open state of the aperture 23e (third aperture), a gap is provided between the fixed aperture sheet 27 and the plurality of aperture blades 23 in a non-contact state with each other. When the plurality of aperture blades 23 move in a direction to reduce the size of the third aperture 23e, the plurality of aperture blades 23 approach the fixed aperture sheet 27 as the warping-up amount increases. When the plurality of aperture blades 23 move from the maximum to the minimum size of the aperture 23e (third aperture), that is, from fully open to small aperture, the tip portion 23d of the aperture blade 23 passes through three regions in the optical axis X direction as the warping-up amount increases.

[0064] The first region is a region on the side opposite to the warping-up direction with respect to the extension line Y2, the second region is a region between the extension line Y2 and the extension line Y1, and the third region is a region on the warping-up direction side with respect to the extension line Y1. The spacer portion 25f of the cover 25 is configured between the extension line Y2 and the extension line Y1 and forms the second region. By providing this second region, even when the warping-up amount of the aperture blade 23 is large, a part of the warping-up amount can be absorbed and stored inside the optical axis X direction of the aperture unit 20, that is, inside the optical axis X direction from the fixed aperture sheet 27. Therefore, it is possible to suppress the aperture blade 23 from protruding outside in the optical axis X direction of the aperture unit 20.

[0065] This second region is preferably thick in the optical axis X direction to suppress the amount of warping. However, if it is too thick, the size of the aperture unit 20 will become large. Therefore, the second region is desirably approximately equal to, or between approximately equal and approximately twice, or between approximately equal and approximately three times the size of the blade chamber in the optical axis X direction where the aperture blades 23 are stored. Further, when giving priority to the aperture unit size, the second region may be between approximately half, or between approximately half and approximately equal, or between approximately half and approximately twice the size of the blade chamber in the optical axis X direction where the aperture blades 23 are stored.

[0066] Therefore, it is possible to prevent the position of the fixed aperture diameter and the position of the aperture opening of the aperture blades 23 from being arranged at positions separated from each other in the light incident direction. <Foreign matter intrusion prevention structure> The aperture unit 20 of the present embodiment is provided with a foreign matter intrusion prevention structure to prevent grease, foreign matter, etc. from entering the gap between the base plate 21 and the cover 25. The foreign matter intrusion prevention structure will be described as follows with reference to FIGS. 18 to 20.

[0067] That is, the foreign matter intrusion prevention structure is constituted by a wall portion (second wall portion) 25d disposed on the outer peripheral side of the cover 25 shown in FIG. 18 and a wall portion (first wall portion) 21c disposed on the outer peripheral side of the base plate 21 shown in FIG. 19. As shown in FIG. 19, the wall portion 21c is disposed so as to cover a part of the outer peripheral portion of the annular main body portion 21a of the base plate 21.

[0068] As shown in FIGS. 10 and 18, the wall portion 25d is a wall-like member erected on a part of the outer periphery along the outer periphery of the main body portion 25a, and is disposed at a position overlapping the wall portion 21c on the side of the base plate 21. In the aperture unit 20 of the present embodiment, in order to avoid contact between grease, foreign matter, etc. and the aperture blades 23 that move in the gap between the base plate 21 and the cover 25, a foreign matter intrusion prevention structure is disposed at the outer peripheral side portion where grease intrusion is a concern.

[0069] Here, the aperture unit 20 employs a configuration in which a plurality of aperture vanes 23 are housed and held in the X direction of the optical axis by sandwiching the aperture vanes 23 between a cover 25 and a base plate 21. In such a configuration, since a gap is formed between the base plate 21 and the cover 25, for example, when there are components with grease or foreign matter attached near the aperture unit 20, there is a risk that the grease or the like will adhere to the aperture unit 20 and penetrate into the interior of the aperture unit 20 through the gap. For example, if the grease that has penetrated through the gap adheres to the aperture vanes 23, the driving load of the aperture vanes 23 may increase, and there is a risk that the rotation operation cannot be performed smoothly.

[0070] In the aperture unit 20 of the present embodiment, a wall portion 21c and a wall portion 25d are provided at portions where grease or the like is likely to adhere. More specifically, the wall portion 25d is provided on the cover 25, and the wall portion 21c is provided on the base plate 21, respectively. The wall portion 21c and the wall portion 25d have a structure in which they are alternately erected from the upstream side and the downstream side in the light incident direction and overlap each other.

[0071] Thereby, the gap visible from the outer peripheral side of the aperture unit 20 is eliminated, and since the wall portions 21c and 25d are alternately arranged, it is possible to effectively prevent foreign matters such as grease from adhering to the aperture vanes 23. In addition, by applying an oil-repellent component such as an oil barrier to the portion having the alternate structure formed by the wall portion 25d and the wall portion 21c, the effect of preventing the intrusion of foreign matters such as grease can be further improved.

[0072] (Embodiment 2) The aperture unit (light shielding unit) 120 according to Embodiment 2 of the present disclosure will be described as follows with reference to FIGS. 21A to 25. The aperture unit 120 of the present embodiment is different from the configuration of the first embodiment in that, in addition to the aperture vanes 23 described in the first embodiment, it includes aperture vanes (movable vanes, second vanes) 123 having a different shape.

[0073] Note that, for components having the same functions and shapes as those in the above Embodiment 1, the same reference numerals are used, and the description thereof is omitted. That is, in the aperture unit 120 of the present embodiment, six aperture vanes (movable vanes, first vanes) 23 shown in FIG. 21A and five aperture vanes 123 shown in FIG. 21B are combined to form an aperture opening (third opening) 123e.

[0074] As shown in FIG. 21A, the aperture vane 23 has a main body portion 23a, a boss 23b (first main shaft), a boss 23c (first sub-shaft), and a tip portion 23d. Since each of these components is the same as those in the above Embodiment 1, the description thereof is omitted here. As shown in FIG. 21B, the aperture vane 123 is longer in overall length than the aperture vane 23 and has a main body portion 123a, a boss 123b (second main shaft), a boss 123c (second sub-shaft), and a rotating portion 123d.

[0075] As shown in FIG. 21B, the main body portion 123a is a plate-shaped member and is formed of a high-rigidity resin such as LCP (Liquid Crystal Polymer), PPS (polyphenylene sulfide), or PA (polyamide). As a result, since the aperture vane 123 is formed using a material with relatively high rigidity, it is possible to suppress the amount of warping of the alternately arranged aperture vanes 23.

[0076] The boss 123b (second main shaft) is provided so as to protrude from the upper surface (the surface facing the drive ring 22) on one end (first end) side of the main body portion 123a as a rotation axis when the plurality of aperture vanes 123 rotate. And the boss 123b (second main shaft) is inserted into a through hole formed in the central portion of the protruding portion 22c of the drive ring 22 described above. For this reason, in the opening / closing operation of the aperture vane 123 described later, when the drive ring 22 is rotationally driven, the boss 123b (second main shaft) moves in the circumferential direction accordingly.

[0077] The boss 123c (second sub-shaft) is provided so as to protrude from the surface of the main body portion 123a on the side opposite to the boss 123b (second main shaft) (the surface facing the cover 25). And the boss 123c (second sub-shaft) is inserted into a cam groove 25c (see FIG. 10) formed in the cover 25 described later. For this reason, when the drive ring 22 is rotationally driven and the aperture blades 123 move in the circumferential direction in the opening / closing operation of the aperture blades 123 described later, the boss 123c (second sub-shaft) moves while being guided by the cam groove 25c accordingly. Thereby, by changing the amount of rotation of the aperture blades 123 according to the amount of rotation of the drive ring 22, the area or the aperture diameter of the opening 123e formed by the plurality of aperture blades 123 is changed, and the amount of light passing through the opening portion of the aperture unit 120 can be adjusted. When the drive ring 22 is rotationally driven, the relative positions of the boss 123b (second main shaft) and the boss 123c (second sub-shaft) with respect to the base plate 21 or the cover 25 change, the aperture blades 123 rotate about the boss 123b (second main shaft), and the size of the opening of the aperture unit 20 changes.

[0078] The rotating portion 123d is provided on the other end (second end) side of the main body portion 123a. When the aperture blades 123 rotate about the boss 123b (second main shaft), the rotating portion 123d moves within the gap between the base plate 21 and the cover 25. And in the aperture unit 120 of the present embodiment, these aperture blades 23, 123 having different shapes are alternately arranged in the circumferential direction.

[0079] Here, when the aperture blade 23 rotates to the state where the aperture diameter of the opening 123e is minimized (closed state), as shown in FIGS. 22A and 22B, the tip portion 23d rotates from between the base plate 21 and the cover 25 to near the optical axis X. At this time, as shown in FIG. 24A, the aperture blade 23 is driven to open and close by moving the boss 23c (first sub-shaft) within a cam groove 25c provided in the cover 25 with the boss 23b (first main shaft) inserted into a through-hole formed at the center of a protruding portion 22c provided on the drive ring 22 as a rotation axis.

[0080] On the other hand, when the aperture blade 123 rotates to the state where the opening diameter of the opening 123e is minimized (closed state), as shown in FIGS. 23A and 23B, the rotating portion 123d rotates within the gap between the base plate 21 and the cover 25 without coming out of the gap between the base plate 21 and the cover 25. For this reason, in any state where the aperture blade 123 desires to rotate to reduce the opening diameter of the opening 123e, neither end thereof comes out of the gap between the base plate 21 and the cover 25. That is, since the aperture blade 123 is always held between the base plate 21 and the cover 25 according to the distance therebetween, the position in the light incident direction is stabilized.

[0081] Therefore, unlike the aperture blade 23, the aperture blade 123 does not warp upward on the downstream side in the light incident direction even when the opening diameter of the opening 123e is reduced. At this time, similar to the aperture blade 23, as shown in FIG. 24B, the aperture blade 123 is driven to open and close by moving the boss 123c (second sub-axis) within the cam groove 25c provided in the cover 25 with the boss 123b (second main axis) inserted into the through hole formed at the center of the protruding portion 22c provided on the drive ring 22 as the rotation axis.

[0082] In the aperture unit 120 of the present embodiment, as described above, the aperture blade 23 shown in FIG. 21A and the aperture blade 123 shown in FIG. 21B are combined and configured to be alternately arranged in the circumferential direction. Thereby, as shown in FIG. 25, even when the six aperture blades 23 and the five aperture blades 123 are rotated so that the opening diameter of the opening 123e of the aperture unit 120 is minimized, the amount of warping upward on the downstream side in the light incident direction can be suppressed.

[0083] Furthermore, since the aperture blade 23 and the aperture blade 123 are used in combination as in the present embodiment, for example, compared with a configuration in which only the aperture blade 123 is used to form the opening 123e, the driving load applied to the driving motor 28 required to move the rotating portion 123d of the aperture blade 123 within the gap between the base plate 21 and the cover 25 can be reduced. According to the configuration of the aperture unit 120 of the present embodiment, as described above, the aperture blade 23 and the aperture blade 123 are combined to suppress the amount of upward warping of the aperture blade 23 on the downstream side in the light incident direction and reduce the load on the drive motor 28.

[0084] In the aperture unit 120 of the present embodiment, similar to the first embodiment, the two protruding portions 22c and 25e provided on the base plate 21 and the cover 25 respectively abut against a part of the aperture blades 23 and 123, thereby suppressing the amount of upward warping of the aperture blades 23 and 123. However, as in the present embodiment, by using a combination of aperture blades 23 and 123 with different shapes, since the aperture blade 123 has a function of suppressing the upward warping of the aperture blade 23, the aperture unit 120 of the present embodiment may be configured without including the two protruding portions 22c and 25e described in the first embodiment.

[0085] [Other Embodiments] Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment, and various modifications are possible without departing from the gist of the disclosure. (A) In the first and second embodiments described above, an example of adjusting the area or the aperture diameter of the openings 23e and 123e by combining a plurality of flat aperture blades 23 and 123 has been described. However, the present disclosure is not limited to this.

[0086] For example, as shown in FIG. 26, an aperture unit (light shielding unit) 220 may be configured using an aperture blade 223 having a shape bent toward the side (upper side in the figure) of the surface (the surface facing the drive ring 22) provided with the boss 223b starting from the bent portion 223f formed at a position near the base (boss 223b) of the main body portion 223a. That is, in this configuration, as shown in FIG. 26, the aperture blades 223 have a shape that is bent in a direction opposite to the warping direction by blade weaving in advance. Therefore, even when the plurality of aperture blades 223 are shifted to a closed state, that is, a state where the aperture diameter or area of the opening 223e is reduced, as shown by the dashed line in FIG. 27, compared with the case (solid line) using the aperture blades 23 of the first embodiment, the warping amount can be more effectively suppressed.

[0087] Note that the direction of bending each aperture blade is not limited to the direction shown in FIG. 26. In a configuration where the side where the tip of the aperture blade is woven is arranged on the opposite side (subject side), it may be bent in the opposite direction to FIG. 26, that is, bent toward the subject side. In the aperture unit 220 of the present embodiment, similar to the first embodiment, the warping amount of the aperture blades 223 can be suppressed by abutting against a part of the aperture blades 223 by two protruding portions 22c (first support portion) and 25e (second support portion) provided on the base plate 21 and the cover 25, respectively.

[0088] However, by using the aperture blades 223 having a bent shape in advance as in the present embodiment, since the aperture blades 223 themselves can have a warping suppression effect, the aperture unit 220 of the present embodiment may be configured not to include the two protruding portions 22c and 25e described in the first embodiment. (B) In the first and second embodiments described above, an aperture unit (light shielding unit) configured such that the aperture blades 23 and 123 warp toward the downstream side (image plane side) in the light incident direction in a state where the plurality of aperture blades 23 and 123 are closed (state where the aperture diameter or area is reduced) has been described as an example. However, the present disclosure is not limited to this.

[0089] For example, in a state where a plurality of aperture blades are closed, an aperture unit configured to warp toward the upstream side (subject side) in the light incident direction may be used. The tip of the aperture blade may be on the subject side where it is woven. (C) In the above-described Embodiments 1 and 2, as an example, a configuration in which the protruding portions 22c (first support portions) and 25e (second support portions) are provided to abut against a part of the aperture blades 23 and 123 and suppress the warping of the plurality of aperture blades 23 and 123 in the closed state of the aperture portion of the aperture unit 20 and 120 has been described. However, the present disclosure is not limited thereto.

[0090] For example, the support portion for suppressing the warping of the plurality of aperture blades in the closed state of the aperture portion of the aperture unit may be a planar member instead of a protruding shape. That is, the shape of the support portion does not need to be a protruding shape, and any member that supports in the direction of suppressing the warping may be used. (D) In the above-described Embodiments 1 and 2, as an example, a configuration in which the protruding portions 22c (first support portions) and 25e (second support portions) are provided on the drive ring 22 and the cover 25, respectively, as support portions for suppressing the warping of the plurality of aperture blades 23 and 123 in the closed state of the aperture portion of the aperture unit 20 and 120 has been described. However, the present disclosure is not limited thereto.

[0091] For example, as a support portion for suppressing the warping of the plurality of aperture blades in the closed state of the aperture portion of the aperture unit, a configuration in which either one of the protruding portions 22c (first support portions) and 25e (second support portions) is provided may be used. (E) In the above-described Embodiments 1 and 2, an example in which the plurality of annular protruding portions 22c provided along the circumferential direction in the substantially annular drive ring 22 are used as the support portion (first support portion) has been described. However, the present disclosure is not limited thereto.

[0092] For example, the shape of the support portion (first support portion) is not limited to an annular protruding portion, and may be other shapes such as a columnar shape or a polygonal shape. (F) In the above-described Embodiments 1 and 2, an example was described in which a plurality of annular protrusions 22c provided along the circumferential direction in the substantially annular drive ring 22 were used as the support portion (first support portion). However, the present disclosure is not limited to this.

[0093] For example, the through-hole of the drive ring 22 (drive ring) may have a bottom portion (first support portion) that constitutes a surface facing the throttle blade 23 side instead of being through, that is, a surface facing the tip of the rotation axis (first main axis), and the bottom portion (first support portion) may be configured to support by contacting the tip of the rotation axis (first main axis). In this case, the bottom portion (first support portion) is formed in a concave shape from the surface of the drive ring 22 (drive ring). And the tip of the rotation axis (first main axis), or the shape of the bottom portion (first support portion) may be a plane, a spherical surface, a conical surface, other rotationally symmetric surfaces, a polygonal pyramid surface, or the like.

[0094] (G) In the above-described Embodiments 1 and 2, an example was described in which a single annular protrusion 25e provided on the inner diameter side of the substantially annular cover 25 was used as the support portion (second support portion). However, the present disclosure is not limited to this. For example, a plurality of arc-shaped or linear protrusions formed along the rotation path of the throttle blade may be used as the support portion (second support portion).

[0095] (H) In the above-described Embodiments 1 and 2, as an example of the blade drive mechanism, bosses 23b (first main axis), 123b (second main axis) that function as rotation axes are provided on the throttle blades 23, 123 side, and through-holes into which the bosses 23b (first main axis), 123b (second main axis) are inserted are provided on the drive ring 22 side. However, the present disclosure is not limited to this.

[0096] For example, a configuration may be adopted in which the rotation axis is provided on the drive ring side, and 23 holes (first main holes), 123 holes (second main holes) into which the rotation axis is inserted are provided on the throttle blades 23, 123 side. In this case, the protruding portions (first support portions) are arranged at substantially equal angular intervals in the circumferential direction so as to protrude annularly from the surface of the main body portion that contacts the surface opposite to the direction in which the aperture blades warp, i.e., the surface on the side opposite to the subject side (cover 25 side), i.e., the image plane side. And the protruding portions contact a part of the aperture blades in the annular portion and support the aperture blades from the subject side.

[0097] Also, a rotation axis is formed at substantially the center of the annularly protruding portion of the protruding portion (first support portion) and is inserted into the hole (first main hole) of the aperture blade. The protruding portion (first support portion) is configured in a convex shape from the surface of the drive ring and supports the vicinity of the rotation axis. Therefore, the blade drive mechanism is not limited to the bosses 23b (first main shafts), 123b (second main shafts) on the aperture blade 23, 123 side and the through holes into which the bosses 23b (first main shafts), 123b (second main shafts) on the drive ring 22 side are inserted. Any drive mechanism may be used as long as the movable blade and the drive ring are engaged and a driving force is transmitted to the movable blade as the drive ring is rotationally driven.

[0098] (I) In the above-described first and second embodiments, as an example of the cam mechanism, an example was described in which bosses 23c (first sub-shafts), 123c (second sub-shafts) that move along the cam groove 25c are provided on the aperture blade 23 side, and cam grooves 25c into which the bosses 23c (first sub-shafts), 123c (second sub-shafts) are inserted are provided on the cover 25 side. However, the present disclosure is not limited to this.

[0099] For example, a configuration may be adopted in which cam grooves (first sub-holes), 123 cam grooves (second sub-holes) are provided on the aperture blades 23, 123 side, and bosses that move along the cam grooves are provided on the cover side. In the opening and closing operation of the aperture blade, when the drive ring is rotationally driven and the aperture blade moves in the circumferential direction, accordingly, the cam grooves (first sub-holes, second sub-holes) on the aperture blade side move while being guided by the bosses on the cover side.

[0100] Accordingly, by changing the amount of rotation of the aperture blades according to the amount of rotation of the drive ring, the area or diameter of the aperture 23e formed by the plurality of aperture blades can be changed, and the amount of light passing through the aperture portion of the aperture unit 20 can be adjusted. When the drive ring is rotationally driven, the relative positions of the bosses 23b (first main shaft), 123b (second main shaft) of the aperture blades 23, 123 with respect to the base plate 21 or the cover 25 of the 23 cam grooves (first secondary holes), 123 cam grooves (second secondary holes) change, the aperture blades rotate about the boss 23b (first main shaft), and the size of the aperture of the aperture unit 20 changes.

[0101] (J) In the above Embodiments 1 and 2, as an example of the cam mechanism, an example was described in which a through hole into which the bosses 23b (first main shaft), 123b (second main shaft) of the aperture blades 23, 123 are inserted is provided on the drive ring side, and a cam groove 25c into which the bosses 23c (first secondary shaft), boss 123c (second secondary shaft) of the aperture blades 23, 123 are inserted is provided on the cover 25 side. However, the present disclosure is not limited thereto.

[0102] For example, a configuration in which the cam groove is provided on the drive ring side and the through hole is provided on the cover side may be used. In the opening and closing operation of the aperture blades, when the drive ring is rotationally driven and the aperture blades move in the circumferential direction, accordingly, the aperture blades rotate about the main bosses (first main shaft and second main shaft) inserted into the through holes of the drive ring, and the secondary bosses (first secondary shaft and second secondary shaft) of the aperture blades move while being guided by the cam grooves on the drive ring side. Accordingly, by changing the amount of rotation of the aperture blades according to the amount of rotation of the drive ring, the area or diameter of the aperture 23e formed by the plurality of aperture blades can be changed, and the amount of light passing through the aperture portion of the aperture unit 20 can be adjusted.

[0103] When the drive ring is rotationally driven, the relative positions of the main bosses (first main shaft and second main shaft) and the secondary bosses (first secondary shaft and second secondary shaft) with respect to the base plate 21 or the cover 25 change, the aperture blades rotate about the main boss 23b (first main shaft and second main shaft), and the size of the aperture of the aperture unit 20 changes. In this case, the protruding portion which is the support portion (first support portion) is formed along the circumferential direction in the cover, protrudes in a plurality of annular shapes, and the through hole is disposed substantially at the center of the annular protruding portion. The protruding portion which is the support portion (first support portion) protrudes from the cover so as to contact the surface on the side opposite to the direction in which the throttle blade warps upward.

[0104] The protruding portion which is the support portion (second support portion) is formed on the floor (first frame body) or the drive ring, and is located near the opening of the throttle unit, or the opening of the floor (first frame body), or the opening of the drive ring. The protruding portion which is the support portion (second support portion) is constituted by a component disposed near the opening of the throttle unit. Further, the support portion (second support portion) is located closer to the central axis of the opening of the throttle unit than the support portion (first support portion), and is provided so as to contact the surface on the same side as the direction in which the throttle blade warps upward. Further, the support portion (second support portion) is provided annularly with respect to the central axis of the opening of the throttle unit. Further, the support portion (second support portion) has a substantially arc shape, or a substantially elliptical shape, or a substantially parabolic shape, or a substantially polynomial curve shape, or a gentle curve shape in a cross-sectional view including the central axis of the opening of the throttle unit.

[0105] (K) In the above-described Embodiments 1 and 2, (I), and (J), the cam mechanism has been described. However, the cam mechanism is not limited thereto. For example, any one of the fixed frame (floor 21 or cover 25) or the drive ring and the movable blade may be engaged, and a cam mechanism in which the movable blade moves as the drive ring is rotationally driven may be used.

[0106] (L) In the above-described Embodiment 1, the throttle unit 20 including 11 movable throttle blades 23 has been described as an example. However, the present disclosure is not limited thereto. For example, the number of movable blades included in the throttle unit is not limited to 11, and may be 10 or less or 12 or more.

[0107] (M) In the above-described Embodiment 2, the aperture unit 120 including six aperture blades 23 and five aperture blades 123 has been described as an example. However, the present disclosure is not limited thereto. For example, the aperture blades of different shapes included in the aperture unit are not limited to the above-described number, and may be a combination of five and six, or may be the same number such as a combination of five and five, six and six, etc.

[0108] Also, the aperture blades of different shapes are not limited to two types, and may be configured by combining three or more types. (N) In the above-described embodiment, an example in which the content of the present disclosure is applied to the aperture unit 20 (light shielding unit) mounted on the interchangeable lens type lens barrel 10 has been described. However, the present disclosure is not limited thereto.

[0109] For example, this light shielding unit is applicable not only to an interchangeable lens barrel but also to a lens barrel integrated with a camera body. (O) In the above-described embodiment, an example in which the content of the present disclosure is applied to the aperture unit 20 (light shielding unit) mounted on the lens barrel 10 disposed on the downstream side in the light incident direction of the fourth lens L4 functioning as a focus lens has been described. However, the present disclosure is not limited thereto.

[0110] The aperture unit 20 may be disposed on the upstream side in the light incident direction of the fourth lens L4 functioning as a focus lens. In that case, the focus lens is disposed in the upward warping direction of the aperture blade, and there is a concern about the interference between the aperture blade and the focus lens during focusing. However, if the content of the present disclosure is applied, the amount of upward warping of the aperture blade is suppressed, so that the risk of interference can be reduced.

Industrial Applicability

[0111] The light-shielding unit of the present disclosure can suppress the warping of the movable vane while smoothly operating the movable vane, and thus can be widely applied to various devices such as optical devices.

Explanation of Signs

[0112] 10 Lens barrel 11 Outer frame 12 Inner frame 13 Actuator 14 Guide pole 15 Fourth lens frame 16 Mount 20 Diaphragm unit (light-shielding unit) 21 Floor (first frame body) 21a Body part 21b Opening (first opening) 21c Wall part (first wall part) 21d Radial regulation part 21e First optical axis direction regulation part 21f Second optical axis direction regulation part 22 Drive ring 22a Body part 22b Opening 22c Protrusion (support part, first support part) 22d Gear part 22e Light-shielding part 22f Radial regulation part 22g First optical axis direction regulation part 22h Second optical axis direction regulation part 23 Diaphragm vane (movable vane, first vane) 23a Body part 23b Boss (first main shaft) 23c Boss (first sub-shaft) 23d Tip part (free end) 23e Opening (third opening) 24 Sheet member 24a Body part 24b Opening 24c Through groove 25 Cover (second frame body) 25a Body part 25b Opening (second opening) 25c Cam groove 25d Wall portion (second wall portion) 25e Protrusion (support portion, second support portion) 25f Spacer portion 26 Mounting screw 27 Fixed opening sheet (fixed opening member) 27a Body portion 27b Opening 28 Drive motor 28a Gear 28b Mounting screw 29a Photointerrupter 29b FPC 120 Diaphragm unit (light shielding unit) 123 Diaphragm blade (movable blade, second blade) 123a Body portion 123b Boss (second main shaft) 123c Boss (second sub - shaft) 123d Rotating portion 123e Opening (third opening) 220 Diaphragm unit (light shielding unit) 223 Diaphragm blade (movable blade) 223a Body portion 223b Boss (rotation shaft) 223c Boss 223d Tip portion 223e Opening 223f Bending portion L1 First lens L2 Second lens L3 Third lens L4 Fourth lens (focus lens) L5 Fifth lens X Optical axis Y1 Extension line radially inward of the fixed opening sheet (fixed opening diameter) Y2 Extension line radially inward of the protrusion (second support portion)

Claims

1. A first frame having a first opening through which light passes; A second frame having a second opening through which the light passes; A plurality of movable vanes disposed between the first frame and the second frame, forming a third opening through which the light passing through the first opening passes, and adjusting the amount of light passing through by changing the size of the third opening; Comprising: The plurality of movable vanes are: A first main shaft or a first main hole provided on the first end side, and a first vane having a free end provided on the second end side opposite to the first main shaft or the first main hole; A second vane having a second main shaft or a second main hole provided on the first end side and a rotating portion provided on the second end side opposite to the second main shaft or the second main hole and rotating along a gap between the first frame and the second frame; The first vane and the second vane are alternately arranged in the circumferential direction in at least some of the vanes; A light shielding unit.

2. Further comprising a drive ring disposed between the first frame and the second frame and rotationally driven when the plurality of movable vanes are opened and closed; The first vane further has a first sub-shaft or a first sub-hole; When the drive ring is rotationally driven, the relative positions of the first main shaft or the first main hole and the first sub-shaft or the first sub-hole change; The first vane rotates about the first main shaft or the first main hole, and the size of the third opening changes; The light shielding unit according to Claim 1.

3. The second vane further has a second sub-shaft or a second sub-hole; When the drive ring is rotationally driven, the relative positions of the second main shaft or the second main hole and the second sub-shaft or the second sub-hole change; The second vane rotates about the second main shaft or the second main hole, and the size of the third opening changes; The light shielding unit according to Claim 2.

4. The light shielding unit according to any one of Claims 1 to 3; A plurality of lens groups for guiding the light incident on the light shielding unit in a desired direction; A lens barrel comprising:

5. The light shielding unit is a diaphragm unit that adjusts the amount of light passing through the plurality of lens groups; The lens barrel according to Claim 4.

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