Light-shielding unit and lens barrel equipped with the same

Abstract

To provide a light-shielding unit capable of suppressing the increase of size in an optical axis direction and reducing the number of components to achieve cost-down, and a lens barrel equipped with the same.SOLUTION: A diaphragm unit 20 includes a bottom board 21, a drive ring 22, a plurality of diaphragm blades 23, a drive motor 24, and a drive gear 24a. The diaphragm blades 23 are arranged between the bottom board 21 and the drive ring 22, and change the size of an opening 23b through which light passed through an opening 21b passes to adjust a light passing amount. The drive motor 24 drives the drive ring 22 to rotate about an optical axis. The drive ring 22 is rotatable about the optical axis with respect to the bottom board 21 outside the diaphragm blades 23 in a radial direction about the optical axis, and engaged in a roughly immobile state in the optical axis direction. When the drive ring 22 is rotated with respect to the bottom board 21 by the drive motor 24, the diaphragm blades 23 are driven to open / close between the bottom board 21 and the drive ring 22.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a light-shielding unit and a lens barrel equipped with the same. [Background technology]

[0002] 2. Description of the Related Art An imaging device such as a camera is provided with a plurality of lens groups, a diaphragm that adjusts the area of ​​an opening through which light passes, a shutter unit, and the like. For example, Patent Document 1 discloses a blade drive mechanism for a camera, which includes a synthetic resin base plate having a cylindrical section formed to protrude on one side at a lateral position of the exposure opening and open on the other side; at least one stator yoke having a coil wound around it, a magnetic pole section at the tip inserted into a groove formed on the circumferential surface of the cylindrical section, and a base attached to one side of the base plate; a permanent magnet rotor inserted from the other side of the base plate and rotatably arranged inside the cylindrical section, with its circumferential surface facing the magnetic pole section of the stator yoke; a gear that is integral with the rotor and rotates outside the cylindrical section; a drive ring that has teeth that mesh with the gear and is rotatably arranged around the exposure opening; and a plurality of blades that operate to open or close the exposure opening depending on the direction of rotation of the drive ring. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-201780 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-079105 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned conventional light blocking unit has the following problems. In other words, the blade drive mechanism for a camera disclosed in the above publication includes a light-shielding unit that drives a second frame (drive ring) sandwiched between a first annular frame (base plate) and a third frame (cover) to rotate using a motor, thereby opening and closing multiple movable blades. However, this type of light blocking unit configuration requires three annular components - a first frame (base plate), a second frame (drive ring), and a third frame (cover) - to drive the multiple movable blades to open and close, which creates the problem of making the unit thicker and larger in the thickness direction (optical axis direction), and increasing the number of parts, which increases costs.

[0005] An object of the present disclosure is to provide a light-shielding unit that can suppress an increase in size in the optical axis direction, reduce the number of parts, and reduce costs, and a lens barrel that includes the same. [Means for solving the problem]

[0006] The light-blocking unit according to the present disclosure includes a first frame, a second frame, a drive source, one or more rotational drive transmitters, and multiple movable blades. The first frame has a substantially annular first main body and a first opening located in the center of the first main body for passing light along the optical axis. The second frame has a substantially annular second main body, a second opening located in the center of the second main body for passing light along the optical axis, and a rotary connector located on the second main body, and is rotatably engaged with the first frame around the optical axis. The drive source is held by the first frame and drives the second frame to rotate around the optical axis relative to the first frame. The one or more rotational drive transmitters transmit rotation or rotational drive force transmitted from the drive source to the rotary connector. At least a portion of the multiple movable blades is disposed in a space formed between the first and second frame, forming a third opening through which light passing through the first or second opening passes. The plurality of movable blades are driven to open and close when the second frame is rotated relative to the first frame by a drive source, and the opening and closing movement changes the size of the third opening to adjust the amount of light passing through. [Effects of the Invention]

[0007] According to the light blocking unit according to the present disclosure, it is possible to suppress an increase in size in the optical axis direction, reduce the number of parts, and reduce costs. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing the configuration of a lens barrel including an aperture unit according to an embodiment of the present disclosure. [Figure 2] 2 is a perspective view of the configuration of the aperture unit in FIG. 1 as viewed from the image plane side in the optical axis direction. [Figure 3] 2 is a perspective view of the configuration of the aperture unit in FIG. 1 as viewed from the subject side in the optical axis direction. [Figure 4] 3 is a plan view (perspective view seen from the subject side in the optical axis direction) showing the configuration of a base plate included in the aperture unit of FIG. 2 etc. [Figure 5] 3 is a plan view (a perspective view seen from the subject side in the optical axis direction) showing the configuration of a drive ring included in the aperture unit of FIG. 2 etc. FIG. [Figure 6A] 3 is a plan view (perspective view seen from the subject side in the optical axis direction) showing the maximum aperture (fully open, fully open, maximum opening) of the aperture blades included in the aperture unit of FIG. 2 etc. [Figure 6B] 3 is a plan view (perspective view seen from the subject side in the optical axis direction) showing the minimum aperture (minimum opening) state of the aperture blades included in the aperture unit of FIG. 2 etc. [Figure 7] FIG. 6B is a plan view showing the configuration of the diaphragm blades in FIG. 6A etc. (viewed from the subject side in the optical axis direction). [Figure 8] 3 is a perspective view seen from the subject side in the optical axis direction, showing the state of the rotation angle position of the drive ring relative to the base plate at the assembly start position (bayonet assembly start position, bayonet claw insertion position) of the aperture unit in FIG. 2 etc. [Figure 9] This is a perspective view seen from the subject side in the optical axis direction, showing the state of the rotation angle position of the drive ring relative to the base plate at the assembly completion position (bayonet assembly completion position, bayonet coupling position) of the aperture unit in Figure 2 etc., and at the maximum aperture position of the aperture blades (fully open position, fully opened position, maximum aperture position). [Figure 10]3 is a perspective view seen from the subject side in the optical axis direction, showing the state of the rotation angle position of the drive ring relative to the base plate when the aperture blades of the aperture unit of FIG. 2 etc. are at the minimum aperture position (minimum opening position). DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, more detailed description than necessary may be omitted. For example, detailed description of well-known matters or redundant description of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. The applicant provides the accompanying drawings and the following description to enable those skilled in the art to fully understand the present disclosure, and does not intend for them to limit the subject matter described in the claims.

[0010] The terms "subject side," "image side," and "incident direction of light" used in the text are shown in Figure 1. The "image side" and the "side opposite to the subject side" are the same side. (Embodiment 1) A diaphragm unit (light blocking unit) 20 according to an embodiment of the present disclosure and a lens barrel 10 including the same will be described below with reference to FIGS. 1 to 10. FIG. (1) Structure of the lens barrel 10 Lens barrel 10 according to this embodiment is a lens barrel that is attached to a camera body (not shown), and as shown in Fig. 1, includes first unit 11, second unit 12, third unit 13, cam frame 14, rectilinear frame 15, first lens L1 to third lens L3, and aperture unit 20. X is the optical axis defined by first lens L1 to third lens L3. Note that optical axis X may also be defined by a single lens, such as only first lens L1.

[0011] 1, first group unit 11 is a substantially cylindrical member that holds first lens L1 on the side closest to the subject in the direction of optical axis X, and is provided so as to move back and forth in the direction of optical axis X. First group unit 11 has cam pins 11a that protrude radially inward from its inner circumferential surface, and rectilinear protrusions 11b that protrude radially outward from its outer circumferential surface. 1, a cam mechanism is formed by cam pins 11a engaging with cam grooves 14a provided in cam frame 14, and rectilinear protrusions 11b engaging with rectilinear grooves 15a provided on the inner diameter side of rectilinear frame 15. When cam frame 14 rotates relative to rectilinear frame 15 with optical axis X as the center, first group unit 11 moves back and forth in the direction of optical axis X due to the cam mechanism.

[0012] As shown in Fig. 1, second unit 12 is a substantially cylindrical member that holds second lens L2 on the image plane side of first lens L1 in the direction of optical axis X. As shown in Fig. 1, second unit 12 is formed substantially integrally with a substantially cylindrical main body 12a, a lens holding portion 12b that holds second lens L2, and a base plate 21 that constitutes aperture unit 20, which will be described later. Furthermore, on the inner peripheral surface side of second unit 12, rectilinear grooves 12c are provided in main body 12a for guiding third unit 13, which is disposed closer to the image plane than second lens L2, in the direction of optical axis X, and third unit 13 can be moved back and forth in the direction of optical axis X along rectilinear grooves 12c. A bayonet rib 12d that engages with a bayonet groove 14c of the cam frame 14 is provided on the outer peripheral surface of the main body 12a of the second group unit 12, and the cam frame 14 is arranged in a state where it can rotate substantially about the optical axis X and is immobile in the direction of the optical axis X with the bayonet rib 12d engaged with the bayonet groove 14c.

[0013] 1, third unit 13 is disposed on the inner peripheral surface side of second unit 12 while holding third lens L3, and moves back and forth in the direction of optical axis X. Third unit 13 has cam pins 13a that protrude radially outward from its outer peripheral surface. 1, cam pin 13a constitutes a cam mechanism, and is engaged with cam groove 14b provided in cam frame 14 and rectilinear groove 12c provided in main body 12a of second group unit 12. When cam frame 14 rotates with respect to second group unit 12, substantially about optical axis X, third group unit 13 moves back and forth in the direction of optical axis X due to the cam mechanism.

[0014] 1, cam frame 14 is disposed on the outer peripheral surface side of main body 12a of second group unit 12, is a substantially cylindrical member that is rotationally driven by manual operating force (not shown), is provided with bayonet grooves 14c that engage with bayonet ribs 12d, and is disposed in a state that is rotatable relative to second group unit 12 about optical axis X. Cam frame 14 is equipped with cam grooves 14a that engage with cam pins 11a of first group unit 11, and cam grooves 14b that engage with cam pins 13a of third group unit 13. When a zoom operation ring (not shown), which is disposed radially outer than rectilinear frame 15 and rotatable about optical axis X, is rotated by manual operation, the manual operating force is transmitted from the zoom operation ring (not shown) to cam frame 14 via an interlocking pin (not shown) that is connected to the manual operation ring (not shown) and cam frame 14.

[0015] Cam grooves 14a and cam grooves 14b are grooves that penetrate the outer and inner peripheral surfaces of cam frame 14 and are formed at an angle with respect to the direction of optical axis X when viewed from the side (outer peripheral side) of lens barrel 10. In other words, cam grooves 14a and cam grooves 14b are grooves that are formed in the cylindrical portion along a substantially spiral trajectory centered on optical axis X. When cam frame 14 is rotated by a manual operating force (not shown), cam pins 11a and cam pins 13a move along cam grooves 14a and 14b, which are substantially spiral-shaped, and this causes first group unit 11 and third group unit 13 to move back and forth in the direction of optical axis X relative to cam frame 14 and second group unit 12.

[0016] 1, rectilinear frame 15 is disposed on the outer diameter side of first unit 11 centered on optical axis X, and is integrally engaged with second unit 12 on the image plane side. Linear grooves 15a that engage with rectilinear protrusions 11b of first unit 11 are provided on the inner peripheral surface of rectilinear frame 15, and first unit 11 can be moved back and forth in the direction of optical axis X along rectilinear grooves 15a.

[0017] As shown in FIG. 1, the first lens L1 to the third lens L3 are an optical system that guides light in the direction of the optical axis X, and are arranged in this order from the subject side to the image plane side in the direction of light incidence. The first lens L1 is disposed inside the first unit 11 and on the subject side, and is disposed closest to the subject among the lens groups included in the lens barrel . The second lens L2 is disposed on the image plane side (opposite the subject side) of the first lens L1. Furthermore, the second lens L2 is disposed inside the second unit 12 and on the subject side.

[0018] The third lens L3 is disposed inside the third unit 13 at a position spaced a predetermined distance from the second lens L2 toward the image plane side. 1, aperture unit (light blocking unit) 20 is disposed between second lens L2 of second unit 12 and first lens L1 of first unit 11, and adjusts the area or aperture diameter through which light transmitted through first lens L1 passes, thereby adjusting the amount of light incident on the imaging element provided on the camera body side. The detailed configuration of aperture unit 20 will be described later. (2) Configuration of aperture unit 20 In the lens barrel 10 of this embodiment, as shown in FIG. 1, a first lens L1 to a third lens L3 are arranged in this order from the subject side in the direction of the optical axis X.

[0019] As shown in FIG. 1, aperture unit 20 is disposed upstream of second lens L2 and is configured substantially integrally with second unit 12. Specifically, in lens barrel 10 of this embodiment, second unit 12 is configured integrally with a base plate 21 (described later). This allows for a smaller dimension of lens barrel 10 or second unit 12 in the optical axis X direction and a reduced number of components compared to when base plate 21 and second unit 12 are configured as separate components. As shown in FIG. 2, aperture unit 20 adjusts the size of aperture diameters (aperture 23b, third aperture) by rotating multiple aperture blades 23 (see FIG. 3) using a drive motor (drive source) 24 to open and close the apertures (apertures) 21b, 22b, and 23b formed at the centers of the respective substantially annular components. The centers of apertures 21b, 22b, and 23b and the apertures of aperture unit 20 are configured to substantially pass through the optical axis X.

[0020] As shown in FIGS. 2 and 3, the aperture unit 20 has a base plate (first frame) 21, a drive ring (second frame) 22, a plurality of aperture blades (movable blades) 23, and a drive motor (drive source) 24. When the aperture blades 23 are narrowed to the maximum (minimum aperture state), the aperture unit 20 is in a state (minimum aperture state) in which the diameter (area) of the aperture (third aperture) 23b formed by the aperture blades 23 is smallest (see FIG. 6B). When the aperture blades 23 are narrowed to the maximum (minimum aperture state), the tip portions 23e of the aperture blades 23 extend further inward than the aperture (first aperture) 21b and the aperture (second aperture) 22b, forming the aperture (third aperture) 23b with the smallest diameter (area).

[0021] 6B around through-hole 23c, tip 23e moves while gradually rotating toward the outer diameter side around optical axis X, i.e., toward opening (first opening) 21b and opening (second opening) 22b, and gradually enters the gap between base plate 21 and drive ring 22. As a result, the diameter (area) of opening (third opening) 23b formed by the plurality of diaphragm blades 23 gradually increases.

[0022] When the multiple aperture blades 23 are further rotated around the through-hole 23c, the tip portions 23e move while rotating further toward the outer diameter side around the optical axis X, and the multiple aperture blades 23, except for the blade portions 23a or part of the tip portions 23e, or almost the entirety of them, enter the gap between the base plate 21 and the drive ring 22, and the opening diameter (area) of the opening (third opening) 23b formed by the multiple aperture blades 23 becomes maximum, that is, the maximum aperture state (maximum opening state, fully open state, fully open state) (see Figure 6A).

[0023] As described above, the aperture unit 20 of this embodiment can adjust the amount of light passing through the opening (third opening) 23b by rotating multiple aperture blades 23 between the minimum aperture state and the maximum aperture (fully open) state. 2 and 3, the base plate (first frame) 21 is a substantially annular member arranged closer to the image plane than the drive ring 22 and the diaphragm blades 23 in the direction of light incidence, and has a substantially annular main body 21a and an opening (first opening) 21b formed in the center of the main body 21a to allow light incident from the subject side to pass through. As shown in Fig. 3, a space is formed between the base plate 21 and the drive ring 22, expanding in the direction of the optical axis X and in a radial direction relative to the optical axis X, and the multiple diaphragm blades 23 are arranged so that they can be opened and closed by rotating within that space around through-holes 23c.

[0024] The detailed configuration of the base plate 21 will be described later. 2 and 3, the drive ring 22 is a substantially annular member located closer to the subject than the base plate 21 and the multiple diaphragm blades 23 in the direction of light incidence, and has a substantially annular main body 22a and an opening 22b formed in the center thereof. The drive ring 22 is driven to rotate relative to the base plate 21 about the optical axis X by a drive motor 24 (described later), thereby rotating the multiple diaphragm blades 23 to open and close them.

[0025] The detailed configuration of the drive ring 22 will be described later. 2 and 3, the plurality of diaphragm blades (movable blades) 23 are arranged in the direction of light incidence (direction of optical axis X) so as to be sandwiched between the base plate 21 and drive ring 22 in the space between them. The plurality of diaphragm blades 23 rotate around a rotation axis 21f (see FIG. 4) provided on the base plate 21 by a known cam mechanism of cam followers 22f and cam groove holes 23d in the space between the base plate 21 and drive ring 22, thereby changing the size (area) of the opening (third opening) 23b and adjusting the amount of light passing through the opening portion of the diaphragm unit 20.

[0026] The detailed configuration of the diaphragm blades 23 will be described later. The drive motor 24 is provided to apply a rotational driving force to the aperture blades 23 when opening and closing the aperture blades 23. The drive motor 24 is fixed on the outer periphery of the base plate 21, centered on the optical axis, and has a drive gear 24a supported by its rotation shaft positioned radially outward of the range in which one or more aperture blades 23 move when driven to open or close, i.e., radially outward of the outer shape of at least one aperture blade 23 at the maximum aperture position. The drive gear 24a is a member serving as a rotation transmission unit that transmits rotation to the drive ring 22 via a gear portion 22c and rotates in conjunction with the rotation of the drive motor 24. As a result, the aperture blades 23 are positioned so as to overlap with the drive gear 24a in the optical axis X direction, but do not interfere with the drive gear 24a, which serves as a rotational drive transmission unit (rotational drive transmission member), even when driven to open or close. The drive motor 24 rotates its rotation shaft by power supplied from an electric circuit (not shown).

[0027] More specifically, the drive motor 24 has a drive gear 24a, which is a rotational drive transmission section (rotational drive transmission member), press-fitted onto its rotary shaft, and the drive gear 24a is disposed so as to mesh with a gear section 22c provided on the drive ring 22. When the rotary shaft of the drive motor 24 rotates in this state, the drive ring 22 rotates relative to the base plate 21 around the optical axis X via the drive gear 24a. When the drive ring 22 rotates relative to the base plate 21, a cam mechanism, which will be described later, rotates the multiple diaphragm blades 23, driving them to open and close.

[0028] In the first embodiment, the base plate 21 is configured as a substantially integral part of the second group unit 12, but this is not limitative. The diaphragm unit 20 may be separate from the second group unit 12 and integrally connected to them with screws or other connecting methods. Furthermore, while the drive gear 24a serving as the rotational drive transmission unit is configured to be disposed radially outward of the range in which the plurality of diaphragm blades 23 open and close, this is not limitative. The rotational drive transmission unit may also be configured such that the rotational shaft of the drive motor 24 is disposed radially outward of the range in which the plurality of diaphragm blades 23 open and close. In this case, the plurality of diaphragm blades 23 are disposed in a position overlapping the rotational shaft of the drive motor 24 in the optical axis X direction (as viewed from a direction perpendicular to the optical axis X) but not overlapping the drive gear 24a. Specifically, the drive gear 24a is disposed closer to the drive ring 22 than the plurality of diaphragm blades 23 in the optical axis X direction and meshes with the gear portion 22c of the drive ring 22. Therefore, even when the plurality of diaphragm blades 23 are driven to open and close, they do not interfere with the rotary shaft and drive gear 24a of the drive motor 24, which is a rotary drive transmission part.

[0029] Furthermore, in the first embodiment, the rotational drive force is transmitted directly from the drive gear 24a fixed to the drive motor 24 to the gear portion 22c of the drive ring 22, but this is not a limitation. One or more intermediate gears supported by the base plate 21 may be added between the gear train of the drive gear 24a fixed to the drive motor 24 and the gear portion 22c of the drive ring 22. The intermediate gear may also include a stepped gear with a deceleration effect. Furthermore, in the first embodiment, the drive gear 24a as a rotational drive transmission unit is arranged radially outward from the range in which the multiple diaphragm blades 23 open and close. However, this is not a limitation. One or more intermediate gears may be added between the gear train of the drive gear 24a fixed to the drive motor 24 and the gear portion 22c of the drive ring 22, and one or more of the drive gear 24a and the one or more intermediate gears may be arranged radially outward from the range in which the diaphragm blades 23 open and close as a rotational drive transmission unit.

[0030] (2-1) Main plate 21 As shown in FIG. 4, the base plate (first frame body) 21 has a main body portion (first main body portion) 21a, an opening (first opening) 21b, an attachment portion 21c, a claw portion 21d, a groove portion 21e, and a rotation axis 21f. 2, a drive motor 24 is disposed on the surface of the base plate 21 on the image plane side, for applying a drive force to drive the plurality of diaphragm blades 23 to open and close.

[0031] As shown in FIG. 4, the main body portion (first main body portion) 21a is a substantially annular plate-like member that forms part or all of the outer shape of the aperture unit 20 on the image plane side in the optical axis X direction, and has an opening 21b formed in its center. As shown in Figure 2, etc., opening (first opening) 21b is an opening portion through which light incident from the subject side of lens barrel 10 passes, and has a diameter or area that is approximately the same as, or slightly larger than, or slightly smaller than, opening (third opening) 23b formed when multiple aperture blades 23 are fully open (open, maximum opening).

[0032] In the first embodiment, the main body 21a and the opening (first opening) 21b are integrally configured as the same member, but this is not limited thereto. The main body 21a and the opening (first opening) 21b may be integrally configured with a separate member including the opening (first opening) 21b, such as a sheet-like member (not shown) that is thin in the optical axis X direction, supported by the main body 21a. 2, the mounting portion 21c is provided on the image plane side surface of the base plate 21 to which the drive motor 24 is attached. As shown in FIG. 4, the mounting portion 21c has a through hole 21ca in its center portion.

[0033] A drive gear 24a of the drive motor 24 is inserted into the through hole 21ca. The drive motor 24 has the drive gear 24a passing through the through hole 21ca and is attached to the attachment portion 21c of the base plate 21 with attachment screws (not shown). As a result, the drive gear 24a engages with the gear portion 22c on the drive ring 22 side via the base plate 21. The claw portions 21d are parts that constitute a bayonet coupling in which the drive ring 22 is supported substantially integrally in the direction of the optical axis X with respect to the base plate 21 so as to be rotatable about the optical axis X, and as shown in Fig. 4, the claw portions 21d are provided at three locations spaced at substantially equal angles (approximately 120 degrees apart) around the optical axis X so as to protrude by a predetermined width radially outward from the outer periphery of the substantially annular main body 21a. The claw portions 21d are provided at three locations along the circumferential direction on the outer periphery of the main body 21a of the base plate 21. During assembly, as shown in Fig. 8, the claw portions 21d are first inserted in the direction of the optical axis X from insertion portions 22da provided on the drive ring 22 side, which will be described later, at an assembly start position, and fitted into the inner diameter side of an outer circumferential wall 22dc of the drive ring 22. From this state, by rotating the drive ring 22 by a predetermined angle relative to the base plate 21 around the optical axis X, as shown in FIG. 9, the claw portion 21d moves below the locking portion 22db (downward in a direction perpendicular to the paper surface in FIG. 5), and the rotational angle position of the drive ring relative to the base plate moves to the assembly completion position (bayonet assembly completion position, bayonet coupling position), thereby achieving the assembly completion state.

[0034] As a result, the claw portion 21d is sandwiched between the locking portion 22db and the main body portion 22a within the above-mentioned specified angle range, and the base plate 21 and the drive ring 22 are approximately integrated so that they do not separate in the direction of the optical axis X, and can be connected in a state where they can rotate relatively around the optical axis X. As shown in Figures 9 and 10, when the rotational angle position of the drive ring relative to the base plate is from the assembly completion position (bayonet assembly completion position, bayonet coupling position) to the drive ring 22 being further rotated relative to the base plate 21 around the optical axis X, the aperture unit 20 enters a usable state (light amount adjustable state) in which the amount of light passing through can be adjusted, and transitions from the maximum aperture position to the minimum aperture position in accordance with the rotation of the drive ring 22.

[0035] As shown in Fig. 4, groove 21e is a bottomed groove that is arranged on the inner periphery of rotation shaft 21f around optical axis X, has a bottom formed in an arc shape, and is provided at nine locations along the circumferential direction on the surface of base plate 21 that faces drive ring 22. Groove 21e is an escape groove that prevents interference with each other even when the tip of cam follower 22f (see Fig. 5) on drive ring 22 is inserted and moves in the circumferential direction around optical axis X (see Figs. 8 to 10).

[0036] Groove portion 21e has a depth in the optical axis X direction that is equal to or greater than the amount of protrusion so as not to interfere in the optical axis X direction with the tip portion of cam follower 22f that protrudes beyond cam groove hole 23d. When drive ring 22 rotates with respect to base plate 21 from the assembly start position to the assembly completion position (maximum aperture position) and from the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position) to the minimum aperture position, cam follower 22f also rotates by the same angle with respect to base plate 21, i.e., moves in the circumferential direction. Therefore, groove portion 21e has a circumferential length with respect to optical axis X that is sufficient to prevent interference with cam follower 22f in the circumferential direction about optical axis X even when drive ring 22 rotates with respect to base plate 21 by approximately the rotation angle from the assembly start position through the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position) to the minimum aperture position.

[0037] As a result, even if the drive ring 22 rotates about the optical axis X relative to the base plate 21 during the assembled state and during the use state (light amount adjustment state), the cam followers 22f on the drive ring 22 side can move in the circumferential direction about the optical axis X along the groove portions 21e without interfering with each other inside the groove portions 21e in the circumferential direction, and therefore the multiple diaphragm blades 23 can be driven to open and close without any hindrance. That is, even if the base plate 21 and the drive ring 22 rotate relatively around the optical axis X in an assembled state, the base plate 21 does not restrict the rotation of the drive ring 22.

[0038] The cam follower 22f on the drive ring 22 side is inserted into the cam groove 23d of the diaphragm blade 23, but the engagement length in the direction of the optical axis X needs to be sufficient so that the mutual engagement does not easily come loose due to external force, etc. For this reason, the cam follower 22f passes through the cam groove 23d and protrudes a predetermined length in the direction of the optical axis X beyond the thickness of the diaphragm blade 23. The groove portion 21e is a groove with a depth in the direction of the optical axis X that is equal to or greater than the amount of protrusion so that it does not interfere with the tip of the cam follower 22f that protrudes beyond the cam groove 23d in the direction of the optical axis X. Therefore, the two do not interfere with each other.

[0039] The rotation shafts 21f are provided on a surface facing the drive ring 22 as rotation axes for the multiple diaphragm blades 23. Nine rotation shafts 21f are provided at approximately equal intervals in the circumferential direction centered on the optical axis X on the outer peripheral side of the main body 21a and on the outer peripheral side (outer diameter side) of the optical axis X of the cam followers 22f of the drive ring 22 (see FIG. 9, etc.). The rotation shafts 21f are erected from the subject-side surface of the approximately annular main body 21a along the optical axis X, facing the direction of the drive ring 22. The rotation shafts 21f are inserted into grooves 22e (see FIG. 5, etc.) of the nine diaphragm blades 23, and function as rotation centers for each of the multiple diaphragm blades 23.

[0040] The rotation shaft 21f is inserted into the through-hole 23c of the diaphragm blade 23, but the engagement length in the direction of the optical axis X must be sufficient to prevent the engagement from easily coming loose due to external force or the like. Therefore, the rotation shaft 21f passes through the through-hole 23c and protrudes a predetermined length in the direction of the optical axis X beyond the thickness of the diaphragm blade 23. The groove 22e is a groove with a depth in the direction of the optical axis X that is equal to or greater than the amount of protrusion so as not to interfere with the tip of the rotation shaft 21f that protrudes beyond the through-hole 23c in the direction of the optical axis X. Therefore, the two do not interfere with each other. Details of the groove 22e will be described later.

[0041] (2-2) Drive ring 22 The drive ring 22 is a member that holds the plurality of diaphragm blades 23 in a gap between itself and the base plate 21, i.e., a space extending in the direction of the optical axis X and radially relative to the optical axis X, and rotates relative to the base plate 21 to rotate the plurality of diaphragm blades 23 to open and close, thereby adjusting the size of the aperture diameter (third opening). As shown in Fig. 5, the drive ring 22 has a substantially annular main body portion (second main body portion) 22a, an opening (second opening) 22b formed in the center thereof, a gear portion 22c, an insertion portion 22da, a locking portion 22db, an outer peripheral wall 22dc, a bayonet groove 22dd, a groove portion 22e, nine cam followers 22f, and a recess 22g. The drive ring 22 is driven to rotate about the optical axis X relative to the base plate 21 by a drive motor 24, thereby rotating the plurality of diaphragm blades 23 and adjusting the opening area of ​​the diaphragm unit 20 (the opening area of ​​the opening (third opening) 23b).

[0042] In this embodiment, the outer diameter (outer diameter of the main body 22a) and inner diameter (diameter of the opening 22b) of the drive ring 22 relative to the optical axis X are approximately the same size (length) as the outer diameter (outer diameter of the main body 21a) and inner diameter (diameter of the opening 21b) of the base plate 21 relative to the optical axis X, but this is not limited to this. When the plurality of diaphragm blades 23 are performing opening and closing operations, as long as the rotation shaft 21f, the cam follower 22f, and the cam groove hole 23d are arranged to overlap with the drive ring 22 when viewed from the optical axis X direction, the outer diameter and the inner diameter of the drive ring 22 do not have to be approximately the same as those of the base plate 21. Furthermore, when the plurality of diaphragm blades 23 are performing opening and closing operations, as long as the drive gear 24a, which is a rotational drive transmission part, is arranged to overlap with the drive ring 22 when viewed from the optical axis X direction, the outer diameter and the inner diameter of the drive ring 22 do not have to be approximately the same as those of the base plate 21.

[0043] 5, main body (second main body) 22a is a substantially annular plate-like member that forms part or all of the outer shape of aperture unit 20 on the subject side in the optical axis X direction, and has opening 22b formed in its center. One side of aperture unit 20 in the optical axis X direction is formed by part or all of base plate 21, and the other side of aperture unit 20 in the optical axis X direction is formed by part or all of drive ring 22.

[0044] The opening (second opening) 22b is an opening portion through which light of the aperture unit 20 passes, and has a diameter or area that is approximately the same as, or slightly larger than, or slightly smaller than, the opening 23b formed when the multiple aperture blades 23 are fully open (open, maximum opening). In the first embodiment, the main body 22a and the opening (second opening) 22b are integrally configured as the same member, but this is not limited thereto. The main body 22a and the opening (second opening) 22b may be integrally configured with a separate member including the opening (second opening) 22b, such as a sheet-like member (not shown) that is thin in the optical axis X direction, supported by the main body 22a.

[0045] The gear portion 22c is a rotational connection portion for rotating the drive ring 22 in conjunction with the rotation of the drive gear 24a serving as a rotational drive transmission portion. As shown in FIG. 5, the gear portion 22c is provided along the circumferential direction on the outer periphery of the substantially annular main body portion 22a, extending radially inward from a portion of the outer periphery, and is formed to mesh with a drive gear 24a (see FIG. 8, etc.) attached to a rotary shaft of the drive motor 24. When the rotational driving force of the drive motor 24 is transmitted to the gear portion 22c via the drive gear 24a, the gear portion 22c drives the drive ring 22 to rotate about the optical axis X relative to the base plate 21. Furthermore, a recess 22g that reduces the thickness of the drive ring 22 in the direction of the optical axis X is provided in a portion inward from the outer periphery of the main body portion 22a where the gear portion 22c is provided (on the inner diameter side in the direction of the optical axis X near the gear portion 22c). In other words, the gear portion 22c is provided along the inner wall of the recess 22g on the outer diameter side centered on the optical axis X. The recess 22g will be described in detail later.

[0046] 5 and 8, the insertion portions 22da have a radial recess amount equal to or greater than the protrusion amount of the claw portions 21d and a circumferential width equal to or greater than the width of the claw portions 21d so that the claw portions 21d on the base plate 21 side can be inserted from the direction of the optical axis X when connecting the drive ring 22 and the base plate 21. As shown in Fig. 5, three insertion portions 22da are provided at approximately equal angular intervals (approximately 120 degrees) around the optical axis X on the inner peripheral side of the outer peripheral wall 22dc at the outermost peripheral part of the main body 22a.

[0047] As shown in Fig. 5, three locking portions 22db are provided at positions adjacent to insertion portions 22da on the image plane side surface of outer peripheral wall 22dc at the outermost peripheral portion of main body portion 22a, at approximately equal angular intervals (approximately 120 degrees) around optical axis X. In the assembly start position of Fig. 8, after claw portions 21d provided on the base plate 21 side of locking portions 22db are inserted into insertion portions 22da, by rotating drive ring 22 around optical axis X relative to base plate 21, claw portions 21d are partially or entirely inserted into bayonet grooves 22dd formed in gaps between locking portions 22db and the surface facing base plate 21 below locking portions 22db (below in a direction perpendicular to the paper surface in Fig. 5), as shown in Figs. As shown in FIG. 2 , the bayonet grooves 22dd have a predetermined length in the circumferential direction around the optical axis X so that the claws 21d do not interfere in the circumferential direction when the drive ring 22 rotates relative to the base plate 21 from the assembly start position to the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position) and further to the minimum aperture position. This allows the claws 21d to relatively rotate along the inside of the bayonet grooves 22dd formed in the drive ring 22 from the assembly start position to the minimum aperture position. Then, the claws 21d are partially or entirely sandwiched (fitted in the bayonet grooves 22dd) between the locking portions 22db and the main body portion 22a while ensuring a predetermined width in the direction of the optical axis X within a predetermined rotation angle range of the drive ring 22 from the assembly start state to the minimum aperture state. As a result, a bayonet coupling (bayonet mechanism) is formed in which the separation between the base plate 21 and the drive ring 22 in the direction of the optical axis X is restricted and rotation between them about the optical axis X is permitted.

[0048] The outer peripheral wall 22dc is a wall-shaped portion that is disposed substantially around the entire periphery of the outermost periphery (outer portion) of the main body portion 22a and has a predetermined length in the direction of the optical axis X, and is formed with an insertion portion 22da, a gear portion 22c, a locking portion 22db, and a bayonet groove 22dd. The bayonet groove 22dd is provided at three locations along the circumferential direction on the outer periphery of the main body portion 22a of the drive ring 22. As shown in FIG. 2, three bayonet grooves 22dd are provided at approximately equal angular intervals (approximately 120 degrees) around the optical axis X on the inner side of the outer peripheral wall 22dc at the outer peripheral portion of the main body 22a, and as described above, form a bayonet coupling together with the claw portion 21d of the base plate 21. 5, groove portion 22e is an arc-shaped, bottomed groove (with a bottom) that is arranged on the outer periphery of cam follower 22f around optical axis X, and nine grooves are provided along the circumferential direction. Groove portion 22e is an escape groove that prevents interference with each other even when the tip of rotation shaft 21f of diaphragm blade 23 provided on the base plate 21 side described above moves in the circumferential direction with the tip inserted (see FIGS. 8 to 10, etc.).

[0049] Groove portion 22e has a depth in the optical axis X direction that is approximately equal to or greater than the amount of protrusion of rotation shaft 21f so as not to interfere in the optical axis X direction with the tip end of rotation shaft 21f that protrudes from through hole 23c. When drive ring 22 rotates with respect to base plate 21 from the assembly start position to the assembly completion position (maximum aperture position) and from the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position) to the minimum aperture position, groove 22e also rotates, i.e., moves in the circumferential direction, by the same angle with respect to base plate 21. Therefore, groove portion 22e has a circumferential length with respect to optical axis X that is sufficient to prevent interference with rotation shaft 21f in the circumferential direction about optical axis X even when drive ring 22 rotates with respect to base plate 21 by approximately the rotation angle from the assembly start position through the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position) to the minimum aperture position.

[0050] As a result, even if the drive ring 22 rotates around the optical axis X relative to the base plate 21 during the assembled state and during the use state (light intensity adjustment state), the rotation shaft 21f on the base plate 21 side can move relatively in the circumferential direction along the groove portion 22e without interfering with each other inside the groove portion 22e in the circumferential direction around the optical axis X, and therefore the multiple diaphragm blades 23 can be driven to open and close without any hindrance. When the base plate 21 and the drive ring 22 are rotated relative to each other around the optical axis X in an assembled state, the drive ring 22 can avoid being restricted by the base plate 21 over the entire rotation angle range in which it can rotate relative to the base plate 21.

[0051] 5, 8, etc., the cam followers 22f are arranged closer to the inner periphery of the optical axis X than the rotation axis 21f of the base plate 21. The cam followers 22f are nine cylindrical parts that are erected at approximately equal angular intervals from the image plane side surface of the main body 22a along the optical axis X direction, facing the direction of the base plate 21, and are inserted into cam groove holes 23d provided in nine diaphragm blades 23, which will be described later.

[0052] As a result, when the drive ring 22 is driven to rotate around the optical axis X, the rotation of the drive ring 22 causes the cam follower 22f to move in the circumferential direction around the optical axis X, and the diaphragm blade 23 having the cam groove hole 23d with which the cam follower 22f is engaged rotates around the rotation axis 21f by a known cam mechanism. Therefore, by rotating the drive ring 22 and rotating the nine diaphragm blades 23, the aperture 23b can be opened or closed, and the size of the diaphragm aperture of the diaphragm unit 20 can be adjusted.

[0053] The cam followers 22f are inserted into the cam grooves 23d of the diaphragm blades 23, but a sufficient engagement length in the direction of the optical axis X is required to prevent the engagement from easily coming loose due to external forces, etc. Therefore, the cam followers 22f pass through the cam grooves 23d and protrude a predetermined distance in the direction of the optical axis X beyond the thickness of the diaphragm blades 23. The grooves 21e have a depth in the direction of the optical axis X that is equal to or greater than the amount of protrusion so as not to interfere with the tips of the cam followers 22f that protrude beyond the cam grooves 23d. When the drive ring 22 rotates relative to the base plate 21 from the assembly start position to the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position) and from the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position) to the minimum aperture position, the cam followers 22f also rotate by the same angle relative to the base plate 21, i.e., move circumferentially. Therefore, the groove 21e has a circumferential length with respect to the optical axis X that is sufficient to prevent interference, that is, the rotation angle from the assembly start position through the assembly completion position (maximum aperture position) to the minimum aperture position.

[0054] As a result, when the drive ring 22 rotates around the optical axis X relative to the base plate 21 during the assembled state and during the use state (light amount adjustment state), the cam followers 22f on the drive ring 22 side can move circumferentially along the groove portions 21e without interfering with each other inside the groove portions 21e, and therefore the multiple diaphragm blades 23 can be driven to open and close without any hindrance. Recess 22g is a recess in the optical axis X direction provided in main body 22a facing base plate 21 along the portion where gear portion 22c is provided in order to form the teeth of gear portion 22c, and has a relief shape in the optical axis X direction to ensure space for assembling and arranging drive gear 24a of drive motor 24. By providing recess 22g, the space in the optical axis X direction between base plate 21 and drive ring 22 is wider than other portions.

[0055] The recess 22g has a shape in which the image plane side surface of the main body 22a is recessed toward the subject in the direction of the optical axis X by at least the width of the teeth of the gear portion 22c and deeper (away from) the position of the tip of the drive gear 24a in the direction of the optical axis X, so that the drive gear 24a meshing with the gear portion 22c does not interfere with the drive ring 22 even when the drive ring 22 rotates relative to the base plate 21 within the range of the usage state (light intensity adjustable state) of the aperture unit 20, i.e., between the maximum aperture position (state in FIG. 9) and the minimum aperture position (state in FIG. 10), and further has a relief shape that widens in the circumferential direction in a substantially fan shape when viewed from the direction of the optical axis X.

[0056] If the drive motor 24 is attached to the base plate 21 at a rotational angle position of the drive ring 22 relative to the base plate 21 such that the recess 22g is not positioned directly in front of the through-hole 21ca of the base plate 21 in the direction of the optical axis X, the drive gear 24a and the main body 22a of the drive ring 22 will interfere with each other in the direction of the optical axis X, making it impossible to attach the drive motor 24 to the attachment portion 21c of the base plate 21. Therefore, when assembling the drive motor 24 to the base plate 21, the rotational angle position of the drive ring 22 relative to the base plate 21 must be such that the recess 22g is positioned directly in front of the through-hole 21ca of the attachment portion 21c in the direction of the optical axis X. In other words, when the drive ring 22 is in an assembled state of the diaphragm unit 20 with respect to the base plate 21 (from the assembly start position to the assembly completion position), i.e., the state shown in Fig. 8, the recess 22g is not present (not arranged) in front of the through hole 21ca into which the drive gear 24a is fitted, in the optical axis X direction, but when the drive ring 22 rotates relative to the base plate 21 to the state shown in Fig. 9, i.e., the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position), the recess 22g comes around (is arranged) in front of the through hole 21ca. As a result, the drive motor 24 cannot be attached to the attachment portion 21c of the base plate 21 in the state shown in Fig. 8, but can be attached in the state shown in Fig. 9.

[0057] In this embodiment, the drive motor 24 is attached to the base plate 21 when the rotation angle position of the drive ring 22 relative to the base plate 21 is as shown in Figure 9. This rotation angle position is the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position). The drive gear 24a and the gear portion 22c need to have a predetermined meshing tooth width to ensure strength when transmitting the drive force.

[0058] The recess 22g has a shape that widens in the direction of the optical axis X so that the drive gear 24a and the gear portion 22c can have the gear tooth width required to ensure strength. The recess 22g has two side walls 22ga and 22gb that are formed extending in a radial direction (radial direction) around the optical axis X and that abut against the drive gear 24a. When the drive ring 22 is rotated by a predetermined angle relative to the base plate 21 from the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position) shown in FIG. 9 with the drive motor 24 attached to the base plate 21 in the direction shown in FIG. 8, i.e., toward the assembly start position (counterclockwise in FIG. 9), the side wall 22ga of the recess 22g abuts against the drive gear 24a, preventing further rotation toward the assembly start position (counterclockwise in FIG. 9). In this state, the drive ring 22 does not come off, i.e., disassemble, relative to the base plate 21. As a result, the side wall 22ga defines one end (first mechanical end) of the drive range that sets the usable state (light intensity adjustable state) in the rotation direction of the drive ring 22 relative to the base plate 21. In this embodiment, this first mechanical end defines the drive range end on the maximum aperture side (open aperture side) of the light intensity adjustable range.

[0059] By attaching the drive motor 24 to the base plate 21 in this way, the drive ring 22 cannot rotate about the optical axis X relative to the base plate 21 until it reaches the state shown in Figure 8, i.e., the assembly start position (bayonet assembly start position, bayonet claw insertion position). In other words, when viewed from the direction of the optical axis X, the positions of the three insertion portions 22da on the drive ring 22 cannot rotate to the positions of the three claw portions 21d on the base plate 21, so the three claw portions 21d will not come off the three insertion portions 22da (the bayonet coupling will not come off). As a result, disassembly of the diaphragm unit 20 can be prevented.

[0060] 10, i.e., when the drive ring 22 is further rotated by a predetermined angle relative to the base plate 21 from the minimum aperture position in the direction from FIG. 9 to FIG. 10, i.e., from the maximum aperture position to the minimum aperture position (clockwise in FIG. 10), the side wall 22gb of the recess 22g abuts the drive gear 24a and prevents further rotation in the direction from the maximum aperture position to the minimum aperture position (clockwise in FIG. 10). As a result, the side wall 22gb defines one end (second mechanical end) of the drive range that sets the usable state (light intensity adjustable state) in the rotation direction of the drive ring 22 relative to the base plate 21. In this embodiment, this second mechanical end defines the drive range end on the minimum aperture side (small aperture side) of the light intensity adjustable range.

[0061] In other words, when the drive motor 24 is driven to rotate while attached to the base plate 21, the drive ring 22 rotates around the optical axis X relative to the base plate 21, and the drive gear 24a of the drive motor 24, which is fixed to the base plate 21 side, moves relatively within a range from a side wall 22ga (first mechanical end) to a side wall 22gb (second mechanical end) of a recess 22g provided on the drive ring 22 side (in reality, the recess 22g moves circumferentially relative to the drive gear 24a), and both ends of the rotational drive range centered on the optical axis X are defined by the side wall 22ga (first mechanical end) and the side wall 22gb (second mechanical end), which extend in a radial direction (radial direction) centered on the optical axis X and are the end faces of the recess 22g.

[0062] As a result, the drive gear 24a moves relatively in the circumferential direction around the optical axis X (in reality, the recess 22g moves circumferentially relative to the drive gear 24a) within the drive range (from the side wall 22ga (first mechanical end) to the side wall 22gb (second mechanical end)) that sets the usable state (light intensity adjustable state) defined by the recess 22g, allowing the drive gear 24a to function as a stopper that defines the rotation range of the drive ring 22 relative to the base plate 21.

[0063] In this embodiment, the connection method for transmitting the rotation of the drive motor 24 (drive source) to the drive ring 22 uses a gear connection between the drive gear 24a (rotational drive transmission part) and the gear part 22c (rotational connection part). However, this is not limiting. Alternatively, a frictional connection may be used, which is achieved by pressing an elastic roller (rotational drive transmission part) against the inner circumferential surface of the outer circumferential wall of the drive ring 22 (rotational connection part). Any rotational drive transmission part may be used as long as it rotates in conjunction with the drive motor 24 and transmits rotation or rotational driving force from the drive motor 24 to the drive ring 22 by contacting and connecting with a part of the drive ring 22, and provides the same effects as those of this embodiment.

[0064] Furthermore, in this embodiment, the drive gear 24a attached to the drive motor 24 is used as the stopper, but this is not limited to this. Any part of the outer shape of the drive motor 24 itself, or any screw or metal fitting for attaching the drive motor 24, that is, any part that is integral with the drive motor 24 and has a shape that is convex toward the recess 22g in the optical axis X direction and can abut against the side wall 22ga or 22gb, can have the same effect as this embodiment as a stopper.

[0065] In this embodiment, the stopper is defined by both ends of the recess 22g, i.e., the side wall 22ga and the side wall 22gb. However, this is not a limitation. Only one of the two, for example, the side wall 22ga (the maximum aperture side, the bayonet assembly start side, or the bayonet claw insertion side) may be used as the stopper. In this case, the other stopper (the side opposite the minimum aperture side, the bayonet assembly start side, or the bayonet claw insertion side) may have a circumferential abutment formed on the claw 21d and the locking portion 22db, which are the bayonet coupling portions between the base plate 21 and the drive ring 22, or on the groove 21e of the base plate 21 and the cam follower 22f of the drive ring 22, or on the rotation shaft 21f of the base plate 21 and the groove 22e of the drive ring 22. This achieves the same effect as the stopper of this embodiment.

[0066] (2-3) Aperture blades 23 2 and 3, the multiple diaphragm blades (movable blades) 23 are arranged in a space of approximately constant size that extends in the optical axis X direction and in a radial direction relative to the optical axis X between a base plate 21 and a drive ring 22 that are aligned in the optical axis X direction. More specifically, the diaphragm unit 20 has one outer shape in the optical axis X direction that is formed by part or all of the base plate 21, and the other outer shape in the optical axis X direction that is formed by part or all of the drive ring 22, and the multiple diaphragm blades (movable blades) 23 are arranged in a space of approximately constant size that extends in the optical axis X direction and in a radial direction relative to the optical axis X that is formed between the two. Furthermore, in the diaphragm unit 20, when the multiple diaphragm blades 23 are performing opening and closing operations, the rotation shaft 21f, the cam follower 22f, and the cam groove 23d are arranged to overlap with the base plate 21 when viewed from the optical axis X direction. Furthermore, when the multiple diaphragm blades 23 are opening or closing, the rotation shaft 21f, cam follower 22f, and cam groove 23d overlap with the drive ring 22 as viewed along the optical axis X. In other words, when the multiple diaphragm blades 23 are opening or closing, the base plate 21 and drive ring 22 are sized or shaped to cover the rotation shaft 21f, cam follower 22f, and cam groove 23d, sandwiching them from both the subject side and the imaging plane side in the optical axis direction. This prevents interference with the operation of the cam mechanism, which is formed by the rotation shaft 21f, cam follower 22f, and cam groove 23d and which rotates and drives the diaphragm blades 23. Furthermore, the multiple diaphragm blades (movable blades) 23 will not fall off the diaphragm unit 20 along the optical axis X, even when they are rotated for opening or closing. Within this space, the plurality of diaphragm blades 23 are driven to open and close by rotating about a rotation axis 21f (see FIG. 4) provided on the base plate 21 by a known cam mechanism of cam followers 22f and cam groove holes 23d in accordance with the rotation of drive ring 22 relative to base plate 21. As a result, the plurality of diaphragm blades (movable blades) 23 change the size (area) of opening (third opening) 23b (see FIG. 3, etc.) to adjust the amount of light passing through the opening portion of diaphragm unit 20.

[0067] More specifically, as shown in FIGS. 6A and 6B, diaphragm blade 23 has blade portion 23a, through-hole 23c, cam groove 23d, and tip portion 23e. As shown in FIG. 7, the blade portion 23a is a plate-like member formed in a blade shape. Through-hole 23c penetrates blade portion 23a in the thickness direction, and a rotation shaft 21f (see FIG. 4, etc.) provided on base plate 21 is inserted into through-hole 23c, causing diaphragm blade 23 to rotate around rotation shaft 21f inserted into through-hole 23c.

[0068] As shown in Fig. 7, cam groove 23d is formed near the end of through-hole 23c, into which rotation shaft 21f is inserted, on the opposite side of through-hole 23c from tip 23e, and penetrates blade 23a in the thickness direction. When drive ring 22 is driven to rotate, cam follower 22f (see Fig. 5, etc.) moves in the circumferential direction about optical axis X. As a result, a force from cam follower 22f acting in the circumferential direction acts as a rotational driving force on cam groove 23d into which cam follower 22f is inserted. As a result, diaphragm blade 23 rotates about rotation shaft 21f by a known cam mechanism, thereby opening and closing the diaphragm aperture.

[0069] When the drive ring 22 rotates relative to the base plate 21 from the assembly start position to the assembly completion position (maximum throttle position), and from the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum throttle position) to the minimum throttle position, the cam followers 22f also rotate by the same angle, i.e., move in the circumferential direction, relative to the base plate 21. Therefore, the cam groove holes 23d have a length such that, even when the drive ring 22 rotates relative to the base plate 21 by approximately the rotation angle from the assembly start position through the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum throttle position) to the minimum throttle position, the ends of the cam groove holes 23d (the ends in the direction in which the cam followers 22f move relatively inside the cam groove holes 23d) do not interfere with each other even when the cam followers 22f move in approximately the circumferential direction.

[0070] As a result, even if drive ring 22 rotates about optical axis X with respect to base plate 21 in the assembled state and in the use state (light intensity adjustment state), cam follower 22f on the drive ring 22 side can move along and inside cam groove 23d without being restricted in movement by the end of cam groove 23d in the direction in which cam follower 22f moves relatively. As a result, cam follower 22f can move in a substantially circumferential direction about the optical axis without being restricted in movement by cam groove 23d in the assembled state and in the use state (light intensity adjustment state), and therefore multiple diaphragm blades 23 can be driven to open and close without hindrance.

[0071] That is, even if the base plate 21 and the drive ring 22 rotate relatively around the optical axis X in an assembled state, the base plate 21 does not restrict the rotation of the drive ring 22. As shown in FIG. 7, the tip portion 23e is a part of the blade portion 23a, and is the tip portion on the free end side opposite the side where the cam groove hole 23d is located with respect to the through hole 23c, and its width as viewed from the optical axis X direction gradually narrows as it moves away from the through hole 23c.

[0072] Here, the mechanism for opening and closing the nine diaphragm blades 23 in the diaphragm unit 20 of this embodiment will be described as follows. That is, as described above, the aperture unit 20 of this embodiment rotates the nine aperture blades 23 around their respective rotation axes 21f, thereby changing the area of ​​the opening (third opening) 23b formed in the central part of the approximately circular ring formed by the nine aperture blades 23, i.e., the center of the optical axis X, as shown in Figures 6A and 6B.

[0073] Specifically, when the cam followers 22f of the drive ring 22 are inserted into the cam groove holes 23d of each of the nine aperture blades 23 and the drive ring 22 is driven to rotate relative to the base plate 21, the nine aperture blades 23 rotate counterclockwise around the through hole 23c into which the rotation shaft 21f is inserted, as shown in Figure 6A, by a known cam mechanism, from a state in which adjacent aperture blades 23 overlap each other.

[0074] As a result, the tip 23e of each diaphragm blade 23 gradually advances toward the optical axis X (toward the inner diameter centered on the optical axis X). Here, when the drive ring 22 is further rotated, each diaphragm blade 23 further rotates counterclockwise, and the size (area) of the diaphragm opening (opening (third opening) 23b) decreases, as shown in FIG. 6B. This allows the area of ​​the aperture to be adjusted between the maximum aperture (fully open, fully open, maximum aperture) state shown in FIG. 6A and the minimum aperture (minimum aperture) state shown in FIG. 6B.

[0075] <Assembly of the aperture unit 20 (from start to finish of assembly)> First, the plurality of diaphragm blades 23 are attached to the base plate 21 from the direction of the optical axis X. Specifically, the rotation shafts 21f of the base plate 21 in the state shown in Fig. 4 are inserted into the through holes 23c of the diaphragm blades 23 one by one, and the nine diaphragm blades 23 are overlapped so as to be in the maximum aperture state (the state shown in Fig. 6A).

[0076] Next, the drive ring 22 is assembled from above in the optical axis X direction to the base plate 21 to which the nine aperture blades 23 are assembled in the maximum aperture state (the state of FIG. 6A). In the aperture unit 20 of this embodiment, a bayonet coupling is adopted to simplify the attachment and detachment of the base plate 21 and the drive ring 22 during assembly and disassembly so that the base plate 21 and the drive ring 22 are rotatable about the optical axis X but are immovable (substantially integral) in the direction of the optical axis X after assembly is complete (during use).

[0077] Therefore, when assembling the drive ring 22 to the main plate 21, it is necessary to assemble the bayonet coupling portion, and a specific assembly method for this will be described below. 8, the positions of the three claws 21d on the base plate 21 side and the positions of the three insertion portions 22da on the drive ring 22 side are aligned when viewed from the direction of the optical axis X. That is, the angular positions of the three claws 21d and the angular positions of the three insertion portions 22da are aligned with respect to the optical axis X.

[0078] At this time, the drive motor 24 has not yet been attached to the mounting portion 21c on the base plate 21 side. Next, from this state, the drive ring 22 is moved relative to the base plate 21 in the optical axis X direction (a direction perpendicular to the paper surface in FIG. 8 ) so that the drive ring 22 abuts against the base plate 21 in the optical axis X direction. In the state of FIG. 8 , i.e., in the assembly start position (bayonet assembly start position, bayonet claw insertion position), when the drive ring 22 abuts against the base plate 21 in the optical axis X direction, the grooves 22 e of the drive ring 22 are extended in the circumferential direction about the optical axis X to the front of the rotation shafts 21 f in the optical axis X direction so that the rotation shafts 21 f of the base plate 21 do not interfere with the main body 22 a of the drive ring 22. In the state of FIG. 8 , the grooves 21 e of the base plate 21 are extended in the circumferential direction about the optical axis X to the front of the cam followers 22 f in the optical axis X direction so that the cam followers 22 f of the drive ring 22 do not interfere with the main body 21 a of the base plate 21. 8, cam grooves 23d are extended to the front of cam followers 22f in the direction of optical axis X when aperture blades 23 are in the maximum aperture state (the state of FIG. 6A) so that cam followers 22f of drive ring 22 do not interfere with blade portions 23a of multiple aperture blades 23. Note that this extended portion of cam grooves 23d follows a circumferential locus about optical axis X when multiple aperture blades 23 are in the maximum aperture position (FIG. 6A). In other words, this extended portion of cam grooves 23d follows a locus that is disposed in the circumferential direction about optical axis X when multiple aperture blades 23 are in the maximum aperture position (FIG. 6A). In other words, even if drive ring 22 rotates relative to base plate 21 in this section, aperture blades 23 are not driven to open or close. In other words, this extended portion of cam grooves 23d follows a locus in which the opening and closing operation (rotational operation) of aperture blades 23 is insensitive (inoperative) to the rotation of drive ring 22 relative to base plate 21.

[0079] In this way, the base plate 21, drive ring 22, and aperture blades 23 do not interfere with each other, and the drive ring 22 can be abutted against the base plate 21 in the direction of the optical axis X in the state shown in Figure 8, i.e., in the assembly start position (bayonet assembly start position, bayonet claw insertion position). 8, the through-hole 21ca for mounting the drive motor 24 does not entirely overlap with the generally arc-shaped recess 22g provided on the drive ring 22 side when viewed from the direction of the optical axis X. In other words, the through-hole 21ca at least partially overlaps with the main body 22a of the drive ring 22 other than the recess 22g when viewed from the direction of the optical axis X. If an attempt is made to mount the drive motor 24 on the mounting portion 21c of the base plate 21 in this state, the drive gear 24a will interfere with the main body 22a, and therefore the drive motor 24 cannot be mounted on the mounting portion 21c of the base plate 21 in the state shown in FIG. 8, i.e., the assembly start position.

[0080] Next, the drive ring 22 is rotated clockwise from the state shown in Fig. 8. This causes a portion of the claw portion 21d of the base plate 21 to enter under the locking portion 22db of the drive ring 22 in a direction perpendicular to the plane of Fig. 9, and enter the gap between the locking portion 22db and the surface of the main body portion 22a facing the base plate 21, i.e., the bayonet groove 22dd. As a result, as shown in Fig. 9, the claw portion 21d and the locking portion 22db form locking portions (minimum) A1, which are overlapping portions when viewed from the optical axis X direction, at three locations at approximately equal angular intervals around the optical axis X in the circumferential direction (rotation angle direction), and the drive ring 22 is placed in the assembly completion position (bayonet assembly completion position, bayonet coupling position). The locking portion (minimum) A1 has a width at which the locking portion 22db presses (covers) the claw portion 21d in the optical axis X direction, and therefore has a size (length) sufficient to ensure the bonding strength between the base plate 21 and the drive ring 22 in the optical axis X direction.

[0081] As a result, the base plate 21 and the drive ring 22 are substantially integrated (substantially immobile) so as not to separate in the direction of the optical axis X, and are locked and capable of relative rotation around the optical axis X, i.e., in a bayonet coupling state. That is, when the base plate 21 and the drive ring 22 are assembled together, for example, when the aperture blades 23 are at their maximum aperture, as shown in FIG. 9, the claw portions 21d of the base plate 21 described above fit into the bayonet grooves 22dd below the locking portions 22db of the drive ring 22 in a direction perpendicular to the plane of the paper in FIG. 9, and the drive ring 22 and the base plate 21 become unable to move relative to each other in the direction of the optical axis X.

[0082] At this time, movement of the drive ring 22 in the direction of the optical axis X is restricted by the claws 21d of the base plate 21 being positioned so as to slip into the bayonet grooves 22dd below the locking portions 22db of the drive ring 22. In other words, the drive ring 22 is held by the base plate 21 in a state in which it is rotatable about the optical axis X while its movement in the direction of the optical axis X is restricted. As a result, the drive ring 22 is assembled to the base plate 21 while maintaining a state in which it can rotate about the optical axis X within a predetermined range from the assembly start position or a position rotated a certain amount toward the assembly completion position from there.

[0083] 9, i.e., in the assembly completion position (bayonet assembly completion position, bayonet claw engagement position), as in the state of Fig. 8, groove 22e of drive ring 22 is arranged in front of rotation shaft 21f in the direction of optical axis X so that rotation shaft 21f of main plate 21 does not interfere with main body 22a of drive ring 22. Also, as in the state of Fig. 8, groove 21e of main plate 21 is arranged in front of cam follower 22f in the direction of optical axis X so that cam follower 22f of drive ring 22 does not interfere with main body 21a of main plate 21. Furthermore, in the state of Fig. 9, in order to drive (rotate) the multiple diaphragm blades 23 to open and close, cam grooves 23 of diaphragm blade 23 are arranged in front of cam follower 22f of drive ring 22 in the direction of optical axis X, and are passed through and engaged with cam follower 22f.

[0084] Even if the drive ring 22 rotates relative to the base plate 21 from the state shown in FIG. 8 to the state shown in FIG. 9, as described above, the position and open / close state of the aperture blades 23 do not change from the state shown in FIG. 8, and the maximum aperture state (fully open, fully open, maximum aperture state) is maintained. 9 to 10, the locus of cam groove 23d is shaped along a direction that is a predetermined angle plus a predetermined angle with respect to the circumferential direction about optical axis X (circumferential direction + predetermined angle direction), in other words, an angle between the radial direction and the circumferential direction about the optical axis, in order to rotationally drive the plurality of diaphragm blades 23. When drive ring 22 rotates relative to base plate 21 in this section, diaphragm blades 23 rotate about rotation axis 21f due to a cam mechanism made up of cam groove 23d that is at a predetermined angle with respect to the circumferential direction about optical axis X and cam follower 22f that moves in the circumferential direction about optical axis X, and is driven to open and close.

[0085] In this way, even in the state shown in FIG. 9, the drive ring 22 can be rotated relative to the base plate 21 without the base plate 21, drive ring 22, and diaphragm blades 23 interfering with each other. The circumferential (rotation angle) dimension of the locking portion (minimum) A1 is set to a length greater than or equal to that required to ensure strength when the claw portion 21d of the base plate 21 and the locking portion 22db of the drive ring 22 are joined.

[0086] The final step in assembling the aperture unit 20 is to attach the drive motor 24 to the base plate 21. To attach the drive motor 24 to the mounting portion 21c of the base plate 21, the drive gear 24a must be passed through the through hole 21ca. In the state shown in FIG. 9, the through hole 21ca overlaps over its entire area with the approximately arc-shaped recess 22g provided on the drive ring 22 side when viewed from the optical axis X direction. In other words, the through hole 21ca does not overlap with the main body portion 22a of the drive ring 22 other than the recess 22g. 9, i.e., in the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position), when attempting to attach the drive motor 24 to the mounting portion 21c of the base plate 21, the drive gear 24a does not interfere with the side wall 22ga, which is the end portion extending in the radial direction (radial direction) centered on one optical axis X of the recess 22g, and therefore the drive gear 24a can be inserted into the through hole 21ca, and the drive motor 24 can be attached to the mounting portion 21c of the base plate 21.

[0087] When the drive ring 22 is rotated by a predetermined angle relative to the base plate 21 from the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position) shown in FIG. 9 with the drive motor 24 attached to the base plate 21 in the direction shown in FIG. 8, i.e., toward the assembly start position (counterclockwise in FIG. 9), the side wall 22ga of the recess 22g abuts against the drive gear 24a, preventing further rotation toward the assembly start position (counterclockwise in FIG. 9). In this state, the drive ring 22 does not come off, i.e., disassemble, relative to the base plate 21. This defines one end (first mechanical end) of the drive range that sets the usable state (light intensity adjustable state) in the rotation direction of the drive ring 22 relative to the base plate 21. In this embodiment, this first mechanical end defines the drive range end on the maximum aperture side (open aperture side) of the light intensity adjustable range.

[0088] In this way, after the rotational angle positions of the base plate 21 and the drive ring 22 are set to the state shown in Figure 9, i.e., the completed assembly state (bayonet assembly completed state), the drive gear 24a is attached near the side wall 22ga, which is one end of the approximately arc-shaped recess 22g provided on the drive ring 22 side, thereby defining the end of the range of relative rotation between the base plate 21 and the drive ring 22, for example, the end of the drive range on the maximum aperture side (open aperture side) in the light intensity adjustable range.

[0089] 9, i.e., with the drive motor 24 removed from the base plate 21 at the assembly completion position (bayonet assembly completion position, bayonet coupling position, maximum aperture position), when the drive ring 22 is rotated relative to the base plate 21 in the direction toward FIG. 8 (counterclockwise in FIG. 9), i.e., toward the assembly start position (bayonet assembly start position, bayonet claw insertion position), there is no contact between the base plate 21 and the drive ring 22 in the rotational direction (circumferential direction), so the base plate 21 can rotate to the assembly start position (bayonet assembly start position, bayonet claw insertion position, position in FIG. 8). At the assembly start position, as described above, the positions of the claw portions 21d of the base plate 21 and the insertion portions 22da of the drive ring 22 match when viewed from the optical axis X direction, so the drive ring 22 comes off the base plate 21 in that state. In other words, the aperture unit 20 comes apart. Therefore, unless the aperture unit 20 is intentionally disassembled from its assembled state, as long as the drive motor 24 is attached to the base plate 21, the aperture unit 20 will not disassemble even if an error occurs in the rotation control of the drive motor 24 during use and the rotation position of the drive ring 22 relative to the base plate 21 runs out of control and moves to the drive end defined by the mechanical end.

[0090] When intentionally disassembling the aperture unit 20 from its fully assembled state, first remove the drive motor 24 from the base plate 21, then rotate the drive ring 22 relative to the base plate 21 in the direction toward Figure 8 (counterclockwise in Figure 9) until it reaches the assembly start position (bayonet assembly start position, bayonet claw insertion position), which will return the bayonet coupling portion to the bayonet assembly start state, making it possible to remove the drive ring 22 from the base plate 21 and disassemble the aperture unit 20.

[0091] In the state shown in Figure 8, the rotating shaft 21f engaged with the groove 22e is positioned slightly inward from the end of the groove 22e. As a result, when the assembly of the main plate 21 and the drive ring 22 shown in Figure 8 begins, a space for disposing the rotating shaft 21f can be formed in the groove 22e. Similarly, in the state shown in Figure 8, the cam follower 22f engaged with the groove 21e is positioned slightly inward from the end of the groove 21e. As a result, when the assembly of the main plate 21 and the drive ring 22 shown in Figure 8 begins, a space for disposing the cam follower 22f can be formed in the groove 21e.

[0092] 9, the drive gear 24a engaged with the gear portion 22c on the drive ring 22 side is positioned inward from the side wall 22ga, which is the end of the recess 22g. As a result, in the positional relationship between the base plate 21 and the drive ring 22 shown in FIG. 9, when the drive motor 24 is assembled to the base plate 21, a space for arranging the drive gear 24a can be formed in the recess 22g.

[0093] <Aperture unit 20 light intensity adjustment (from maximum aperture to minimum aperture)> When the drive ring 22 is further rotated by the drive motor 24 from the state shown in FIG. 9 to the side where the aperture opening (third aperture 23b) is closed, that is, the minimum aperture side, the state shown in FIG. 10 is reached. 10, i.e., at the minimum aperture position (minimum opening position), as in the state of Fig. 9, groove 22e of drive ring 22 is arranged in front of rotation shaft 21f in the direction of optical axis X to prevent interference between rotation shaft 21f of base plate 21 and main body 22a of drive ring 22. Also, as in the state of Fig. 9, groove 21e of base plate 21 is arranged in front of cam follower 22f in the direction of optical axis X to prevent interference between cam follower 22f of drive ring 22 and main body 21a of base plate 21. Furthermore, in the state of Fig. 10, in order to drive (rotate) the multiple diaphragm blades 23 to open and close, cam groove 23d of diaphragm blade 23 is arranged in front of cam follower 22f of drive ring 22 in the direction of optical axis X, and is passed through and engaged with cam follower 22f.

[0094] As described above, the trajectory of the cam groove hole 23d from the state in FIG. 9 to the state in FIG. 10 has a shape that follows a direction that is a predetermined angle plus the circumferential direction centered on the optical axis X (circumferential direction + predetermined angle direction), in other words, an angle direction between the radial direction and the circumferential direction centered on the optical axis, and when the drive ring 22 rotates with respect to the base plate 21, the diaphragm blades 23 are driven to open and close. In this way, even in the state shown in FIG. 10, the drive ring 22 can be rotated relative to the base plate 21 without the base plate 21, drive ring 22, and diaphragm blades 23 interfering with each other.

[0095] 10, the claw portion 21d on the base plate 21 side enters the lower side of the drive ring 22 side in a direction perpendicular to the paper surface, and is positioned in the gap between the locking portion 22db and the surface of the main body portion 22a facing the base plate 21, i.e., in the bayonet groove 22dd. The claw portion 21d and the locking portion 22db form locking portions (maximum) A2, where they overlap as viewed from the optical axis X direction, at three locations approximately equiangularly spaced apart in the circumferential direction (rotation angle direction) around the optical axis X. The locking portion (maximum) A2 is the width by which the locking portion 22db presses (covers) the claw portion 21d in the optical axis X direction, and therefore the larger (longer) this width is, the higher (stronger) the coupling strength between the base plate 21 and the drive ring 22 in the optical axis X direction is. Since the circumferential (rotation angle) dimension of the locking portion (maximum) A2 is larger (longer) than that of the locking portion (minimum) A1, there is no problem with the strength when the claw portion 21d of the base plate 21 and the locking portion 22db of the drive ring 22 are joined together.

[0096] As a result, even if the drive ring 22 is rotated to the minimum aperture end (minimum opening end) after the drive ring 22 is assembled to the base plate 21, the drive ring 22 and the base plate 21 will not separate in the optical axis X direction. When the drive ring 22 is rotated by a predetermined angle relative to the base plate 21 from the state shown in FIG. 10 (minimum aperture position) in the direction from FIG. 9 to FIG. 10, i.e., in the direction from the maximum aperture position to the minimum aperture position (clockwise in FIG. 10), the drive gear 24a of the drive motor 24 abuts against the side wall 22gb, which is the end of the recess 22g on the drive ring 22 side.

[0097] 8 to 10 , in the diaphragm unit 20 of this embodiment, the gear portion 22c on the drive ring 22 side and the drive gear 24a, which is a rotational drive transmission portion of the drive motor 24 fixed to the base plate 21 side, are arranged to engage with each other radially outward from the one or more diaphragm blades 23. In other words, at least a part of the engagement portion between the drive gear 24a, which is a rotational drive transmission portion, and the gear portion 22c is arranged on the outer diameter side from the optical axis X of the range in which the one or more diaphragm blades 23 operate by opening and closing drive, and is arranged close to the one or more diaphragm blades 23; in other words, in the case of this embodiment, it is arranged radially outward from the optical axis X of the outer portion of the one or more diaphragm blades 23 at the maximum aperture position, and is arranged close to the one or more diaphragm blades 23.

[0098] As a result, when viewed from the direction of optical axis X, the range in which diaphragm blade 23 rotates and the engagement portion between gear portion 22c and drive gear 24a, which is the rotational drive transmission portion, do not overlap, so malfunctions due to mutual interference are avoided while suppressing an increase in the radial size perpendicular to optical axis X. In addition, by eliminating one of the three annular members, namely, the first frame (base plate), second frame (drive ring), and third frame (cover), which were conventionally required in the configuration of an diaphragm unit, an increase in size in the direction of optical axis X is prevented, and drive ring 22 can be rotated. As described above, the same effect can be achieved by using the rotation shaft of drive motor 24 as one of the rotational drive transmission portions and arranging the rotation shaft on the outer diameter side, centered on optical axis X, of the range in which one or more diaphragm blades 23 operate by opening and closing drive, and close to one or more diaphragm blades 23.

[0099] 5, the gear portion 22c is disposed on the inner diameter surface (inner peripheral surface) of the outer peripheral wall 22dc on the outermost side (outer diameter side) of the main body portion 22a of the drive ring 22, centered on the optical axis X. As a result, by arranging the gear portion 22c at a position radially outward of the range in which one or more aperture blades 23 rotate, interference between the gear portion 22c and rotational drive transmission portions such as the drive gear 24a that transmits the rotational force of the drive motor 24 to it and the one or more aperture blades 23 is prevented, while ensuring as much space as possible in which the aperture blades 23 can move, suppressing an increase in the radial size perpendicular to the optical axis X, and by eliminating one of the three annular members, namely the first frame (base plate), second frame (drive ring), and third frame (cover), which were previously required in the configuration of an aperture unit, it is possible to avoid an increase in size in the direction of the optical axis X and to rotate the drive ring 22.

[0100] In this embodiment, the recess 22g on the drive ring 22 side abuts against the drive gear 24a at both ends (side walls 22ga, 22gb) of the substantially arcuate shape, thereby defining the range of relative rotation between the base plate 21 and the drive ring 22. As a result, by having the drive gear 24a function as a stopper member that defines the range of relative rotation between the base plate 21 and the drive ring 22, it is possible to prevent the base plate 21 from separating from the drive ring 22 in the direction of the optical axis X while defining the range of use of the diaphragm unit 20. Furthermore, since there is no need to provide a separate stopper member, the number of parts can be reduced. As described above, a part of the outer shape of the drive motor 24 itself or a screw or metal fitting for attaching the drive motor 24, that is, any part that is integral with the drive motor 24 and has a shape that protrudes toward the recess 22g in the direction of the optical axis X and can abut against the side wall 22ga or 22gb, can have the same effect as this embodiment as a stopper. Furthermore, as described above, if only one of the ends of the recess 22g, for example, only the side wall 22ga side (maximum aperture side, bayonet assembly start side, bayonet claw insertion side) is used as a stopper, and the other stopper (minimum aperture side, bayonet assembly start side, opposite the bayonet claw insertion side) is used by forming a circumferential abutment portion on the claw portion 21d and the locking portion 22db, which are the bayonet connection portion between the base plate 21 and the drive ring 22, then the same effect as in this embodiment can be achieved as a stopper.

[0101] Furthermore, in the aperture unit 20 of this embodiment, the engagement length in the circumferential direction about the optical axis X between the base plate 21 and the drive ring 22, which are engaged with each other by a bayonet connection, is smallest when the aperture blades 23 are in the maximum aperture state (fully open, fully open, maximum aperture, assembled) (see FIG. 9), and is largest when the aperture blades 23 are in the minimum aperture state (fully closed) (see FIG. 10). Here, when the base plate 21 is rotated by a predetermined angle relative to the drive ring 22 in a direction in which the engagement length becomes even shorter from the maximum narrowing position (assembly completion position) where the engagement length of the bayonet coupling is at its smallest, i.e., in the direction from Figure 9 to Figure 8 (counterclockwise in Figure 9), the drive gear 24a comes into contact with the side wall 22ga, which is the end of the recess 22g, at a position just before the engagement length becomes 0, thereby restricting the rotation of the base plate 21.

[0102] Furthermore, in the aperture unit 20 of this embodiment, when the plurality of aperture blades 23 are performing an opening / closing operation, the rotation shaft 21f, the cam followers 22f, and the cam grooves 23d are arranged to overlap with the drive ring 22, as viewed from the opposite side of the base plate 21 in the optical axis X direction. In other words, when the plurality of aperture blades 23 are performing an opening / closing operation, the main body 22a of the drive ring 22 has a size or shape that covers at least the rotation shaft 21f, the cam followers 22f, and the cam grooves 23d, as viewed from the optical axis X direction. This allows the drive ring 22, which constitutes part or all of one outer shape of the aperture unit 20 in the optical axis X direction, to cover the rotation shaft 21f, the cam followers 22f, and the cam grooves 23d from the opposite side of the base plate 21 in the optical axis X direction, so that the cam mechanism that rotates the plurality of aperture blades 23 to open and close the aperture blades 23 is not impaired.

[0103] Furthermore, in the diaphragm unit 20 of this embodiment, the drive gear 24a, which is a rotational drive transmission part, is arranged to overlap with the drive ring 22 when viewed from the opposite side of the base plate 21 in the direction of the optical axis X. In other words, the main body 22a of the drive ring 22 has a size or shape that covers at least the drive gear 24a, which is a rotational drive transmission part, when viewed from the direction of the optical axis X. As a result, the drive ring 22, which constitutes part or all of one side of the outer shape of the diaphragm unit 20 in the direction of the optical axis X, can cover the drive gear 24a, which is a rotational drive transmission part, from the opposite side of the base plate 21 in the direction of the optical axis X, so that the rotational drive of the drive gear 24a is not hindered by the adhesion of dust, foreign matter, etc.

[0104] This allows the diaphragm blades 23 to be driven to open and close within a range overlapping with the drive ring 22 when viewed from the optical axis X direction. Furthermore, in the aperture unit 20 of this embodiment, one side of the outer shape in the optical axis X direction is formed by part or all of the base plate 21, and the other side of the outer shape in the optical axis X direction is formed by part or all of the drive ring 22. In other words, one side of the outer shape in the optical axis X direction is formed by part or all of the base plate 21, and the other side of the outer shape in the optical axis X direction is formed by part or all of the drive ring 22. When the multiple aperture blades 23 are opening or closing, the base plate 21 and the drive ring 22 are shaped to partially or completely cover the multiple aperture blades 23 so that they are sandwiched between them from both the subject side and the imaging plane side in the optical axis direction. Therefore, the multiple aperture blades 23 will not fall off the aperture unit 20 even when they are rotationally driven to open or close. In this way, there is no problem in eliminating one of the three annular components that were previously required in the configuration of an aperture unit: the first frame (base plate), the second frame (drive ring), and the third frame (cover), and the size of the aperture unit in the direction of the optical axis X can be reduced.

[0105] <Main features> As shown in FIG. 2, the diaphragm unit 20 of this embodiment includes a base plate 21, a drive ring 22, multiple diaphragm blades 23, a drive motor 24, and one or more drive gears 24a. The base plate 21 has a substantially annular main body 21a and an opening 21b provided in the center of the main body 21a for passing light along the optical axis. The drive ring 22 has a substantially annular main body 22a, an opening 22b provided in the center of the main body 22a for passing light along the optical axis, and a gear portion 22c provided on the main body 22a, and is engaged with the base plate 21 in a manner rotatable around the optical axis. The drive motor 24 is held by the base plate 21 and drives the drive ring 22 to rotate relative to the base plate 21 around the optical axis. The one or more drive gears 24a transmit the rotation or rotational driving force transmitted from the drive motor 24 to the gear portion 22c. The multiple aperture blades 23 are at least partially arranged in the space formed between the base plate 21 and the drive ring 22, and form an opening 23b through which light that has passed through opening 21b passes. The size of opening 23b is changed by opening and closing (rotating) the operation (rotational operation) to adjust the amount of light passing through, and the opening and closing (rotational drive) is performed when the drive ring 22 rotates relative to the base plate 21 by the drive motor 24.

[0106] This allows the aperture blades 23 to open and close in the gap between the base plate 21 and the drive ring 22, so that the drive ring 22 can also function as a conventional third frame (cover). As a result, the number of parts can be reduced compared to the conventional art, and costs can be reduced while suppressing the size in the optical axis direction.

[0107] [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 above embodiment, an example has been described in which the rotation shaft 21f, which serves as the rotation shaft of the plurality of diaphragm blades 23, is provided on the base plate 21 side. However, the present disclosure is not limited to this.

[0108] For example, the rotation axis of the diaphragm blades (movable blades) may be integrally arranged on the drive ring (second frame) side, rather than on the base plate (first frame) side. In this case, the same effects as those obtained in the above embodiment can be obtained. (B) In the above embodiment, an example has been described in which the rotation shaft 21f, which serves as the rotation shaft of the plurality of diaphragm blades 23, is provided on the base plate 21 side. However, the present disclosure is not limited to this.

[0109] For example, the rotation axis of the aperture blade (movable blade) may be configured other than on the base plate (first frame), for example, the rotation axis may be integrally arranged on the aperture blade (movable blade) itself, and a hole that engages with it may be provided on the base plate side. In this case, the same effects as those obtained in the above embodiment can be obtained. (C) In the above embodiment, an example has been described in which the cam followers 22f that engage with the cam grooves 23d of the multiple diaphragm blades 23 are provided on the drive ring 22. However, the present disclosure is not limited to this.

[0110] For example, the cam pins that engage with the cam grooves of the diaphragm blades (movable blades) may be provided on the main plate (first frame) side, instead of on the drive ring side. In this case, the same effects as those obtained in the above embodiment can be obtained. (D) In the above embodiment, an example has been described in which the cam followers 22f that engage with the cam grooves 23d of the multiple diaphragm blades 23 are provided on the drive ring 22. However, the present disclosure is not limited to this.

[0111] For example, the engaging cam pin may be arranged on the diaphragm blade (movable blade) side, and the cam groove may be arranged on the drive ring side, the main plate side, or the cover side. In this case, the same effects as those obtained in the above embodiment can be obtained. (E) In the above embodiment, an example has been described in which the drive gear 24a of the drive motor 24 fixed to the base plate 21 and the recess 22g provided on the drive ring 22 side are used as members that define the range of relative rotation of the base plate 21 with respect to the drive ring 22. However, the present invention is not limited to this.

[0112] For example, a microcomputer that controls the rotation of a drive motor (drive source) may be used as a configuration for defining the range of relative rotation (drive range) of the base plate (first frame) with respect to the drive ring (second frame). Even in this case, the range of relative rotation (drive range) of the base plate (first frame) with respect to the drive ring (second frame) can be defined by controlling the rotation of the drive motor (drive source) using a microcomputer.

[0113] (F) In the above embodiment, an example has been described in which the aperture unit 20 includes nine movable aperture blades 23. However, the present disclosure is not limited to this. For example, the number of movable blades included in the diaphragm unit is not limited to nine, but may be eight or less, or ten or more.

[0114] (G) In the above embodiment, an example has been described in which the contents of the present disclosure are applied to an aperture unit 20 (light blocking unit) mounted on an interchangeable lens barrel 10 that is detachable from a camera body. However, the present disclosure is not limited to this. For example, the light-shielding unit is not limited to interchangeable lens barrels, but can also be applied to lens barrels that are integrated with the camera body.

[0115] (H) In the above embodiment, an example has been described in which the contents of the present disclosure are applied to aperture unit 20 (light blocking unit) 20 mounted on lens barrel 10, which is disposed downstream in the direction of light incidence of second lens L2, which functions as a focus lens. However, the present disclosure is not limited to this.

[0116] For example, the diaphragm unit may be disposed upstream of the second lens L2 that functions as a focus lens in the direction of light incidence. (I) In the above embodiment, an example has been described in which base plate 21 of aperture unit 20 is configured substantially integrally as part of second group unit 12 of lens barrel 10. However, the present disclosure is not limited to this.

[0117] For example, the aperture unit 20 and the second group unit 12 may be separate bodies that are integrally joined together with screws or other joining methods. (J) In the above embodiment, an example has been described in which the stopper is the drive gear 24a attached to the drive motor 24. However, the present disclosure is not limited to this.

[0118] For example, if a part of the shape of the drive motor 24 itself, or a screw or metal fitting for attaching the drive motor 24, that is, a part that is integral with the drive motor 24 and has a shape that protrudes toward the recess 22g in the direction of the optical axis X and can abut against the side wall 22ga or 22gb, then the stopper will have the same effect as this embodiment. (K) In the above embodiment, an example was described in which the stoppers were defined by both ends of the recess 22g, that is, the side walls 22ga and 22gb, but the present disclosure is not limited to this.

[0119] Only one of the two, for example, only the side wall 22ga side (maximum aperture side, bayonet assembly start side, bayonet claw insertion side) may be used as the stopper. In this case, the other stopper (opposite the minimum aperture side, bayonet assembly start side, and bayonet claw insertion side) may have a similar effect as the present embodiment as a stopper by forming circumferential abutment portions on the claw portions 21d and the locking portions 22db, which are the bayonet coupling portions between the base plate 21 and the drive ring 22, or by forming circumferential abutment portions on the groove portions 21e of the base plate 21 and the cam followers 22f of the drive ring 22, or by forming circumferential abutment portions on the rotation shafts 21f of the base plate 21 and the groove portions 22e of the drive ring 22.

[0120] (L) In the above embodiment, an example has been described in which the drive gear 24a, as the rotational drive transmission part, is disposed on the outer diameter side of the range in which the multiple diaphragm blades 23 open and close. However, the present disclosure is not limited to this. For example, the rotational drive transmission unit may be configured such that the rotational shaft of the drive motor 24 is disposed radially outward of the range in which the multiple diaphragm blades 23 open and close. In this case, the multiple diaphragm blades 23 are disposed in a position overlapping with the rotational shaft of the drive motor 24 in the direction of the optical axis X (as viewed from a direction perpendicular to the optical axis X), but are disposed in a position not overlapping with the drive gear 24a.

[0121] Specifically, the drive gear 24a is disposed closer to the drive ring 22 than the plurality of diaphragm blades 23 in the direction of the optical axis X (as viewed from a direction perpendicular to the optical axis X), and is engaged with the gear portion 22c of the drive ring 22. Therefore, even when the plurality of diaphragm blades 23 are driven to open and close, they do not interfere with the rotation shaft of the drive motor 24, which is a rotation drive transmission portion, and the drive gear 24a. (M) In the above embodiment, the main body 21a and the opening (first opening) 21b are integrally formed as a single member, but the present disclosure is not limited to this.

[0122] For example, the main body 21a and the main body 21a may be integrally configured with a separate member including the opening (first opening) 21b, such as a sheet-like member (not shown) that is thin in the direction of the optical axis X. This configuration also provides the same effects as the present embodiment. (N) In the above embodiment, the main body 22a and the opening (second opening) 22b are integrally formed as a single member, but the present disclosure is not limited to this.

[0123] For example, the main body 22a and the second opening 22b may be integrally configured with a separate member, such as a sheet-like member (not shown) that is thin in the direction of the optical axis X, supported by the main body 22a. This configuration also provides the same effects as the present embodiment. (O) In the above embodiment, an example has been described in which the outer diameter (outer diameter of main body 22a) and inner diameter (diameter of opening 22b) of drive ring 22 relative to optical axis X are approximately the same size (length) as the outer diameter (outer diameter of main body 21a) and inner diameter (diameter of opening 21b) of base plate 21 relative to optical axis X. However, the present disclosure is not limited to this.

[0124] For example, when the multiple aperture blades 23 are performing opening and closing operations, as long as the rotation axis 21f, the cam follower 22f, and the cam groove hole 23d are arranged to overlap with the drive ring 22 when viewed from the direction of the optical axis X, the outer diameter and the inner diameter of the drive ring 22 do not have to be approximately the same as those of the base plate 21. Furthermore, as long as the drive gear 24a, which is the rotational drive transmission unit, is positioned so as to overlap the drive ring 22 when viewed from the optical axis X direction while the multiple diaphragm blades 23 are opening and closing, the outer and inner diameters of the drive ring 22 do not have to be substantially the same as those of the base plate 21. For example, the outer and inner diameters of the drive ring 22 may be smaller than those of the base plate 21. Even with this configuration, the same effect as that of this embodiment can be achieved.

[0125] (P) In the above embodiment, an example has been described in which gear coupling between the drive gear 24a, which is a rotational drive transmission part, and the gear part 22c, which is a rotational connection part, is used as a connection method for transmitting the rotation of the drive motor 24, which is a drive source, to the drive ring 22. However, the present disclosure is not limited to this.

[0126] For example, a connection method may be a frictional connection by pressing between an elastic roller, which is the rotational drive transmission part, and the inner peripheral surface of the circumferential wall on the outer circumferential side of the drive ring 22, which is the rotational connection part. The rotational drive transmission part may be any part that rotates in conjunction with the drive motor 24 and transmits rotation or rotational drive force from the drive motor 24 to the drive ring 22 by contacting and connecting with a part of the drive ring 22, and has the same effect as this embodiment.

[0127] (Q) In the above embodiment, an example has been described in which the rotational driving force is transmitted directly from the drive gear 24a fixed to the drive motor 24 to the gear portion 22c of the drive ring 22. However, the present disclosure is not limited to this. For example, one or more intermediate gears supported by the main plate 21 may be added between the gear train of the drive gear 24a fixed to the drive motor 24 and the gear portion 22c of the drive ring 22. The intermediate gear may also include a stepped gear that has a speed reduction effect. This configuration also provides the same effect as this embodiment.

[0128] (R) In the above embodiment, an example has been described in which the drive gear 24a, as the rotational drive transmission part, is disposed on the outer diameter side of the range in which the multiple diaphragm blades 23 open and close. However, the present disclosure is not limited to this. For example, one or more intermediate gears may be added between the gear train of drive gear 24a fixed to drive motor 24 and gear portion 22c of drive ring 22, and one or more of drive gear 24a and the one or more intermediate gears may function as a rotational drive transmission unit and be arranged on the outer diameter side of the range in which diaphragm blades 23 open and close. This configuration also has the same effect as this embodiment.

[0129] <Additional Notes> The above description of the embodiments discloses the following techniques. (Technology 1) The light blocking unit according to Technology 1 is a first frame body having a substantially annular first main body portion and a first opening provided in a central portion of the first main body portion and allowing light to pass along an optical axis direction; a second frame body having a substantially annular second main body portion, a second opening provided in a central portion of the second main body portion and allowing light to pass along the optical axis direction, and a rotary connection portion provided on the second main body portion, and engaging with the first frame body in a state rotatable about the optical axis; a drive source held by the first frame and configured to rotate the second frame relative to the first frame around the optical axis; one or more rotational drive transmission units that transmit rotation or rotational drive force transmitted from the drive source to the rotation connection unit; a plurality of movable blades, at least a portion of which is disposed in a space formed between the first frame body and the second frame body, which form a third opening through which the light that has passed through the first opening or the second opening passes, which are driven to open and close when the second frame body is rotated relative to the first frame body by the drive source, and which change the size of the third opening by the opening and closing operation to adjust the amount of light that passes through; It is equipped with:

[0130] (Technology 2) The light blocking unit according to the second technique is the light blocking unit according to the first technique, The rotational connection portion is provided on the outer periphery of the second frame. (Technology 3) The light-shielding unit according to the third technique is the light-shielding unit according to the first or second technique, The rotary connection portion and one or more members of the one or more rotary drive transmission portions are arranged to engage radially outward from one or more of the plurality of movable blades, centered on the optical axis.

[0131] (Technology 4) The light-shielding unit according to the fourth technique is a light-shielding unit according to any one of the first to third techniques, The one or more rotational drive transmission parts are configured by gears that rotate in conjunction with the drive source, and the rotational connection part is configured by a gear provided on the outer periphery of the second frame body.

[0132] (Technology 5) The light-shielding unit according to the fifth technique is a light-shielding unit according to any one of the first to fourth techniques, The second frame further has a recess in the optical axis direction in which a protruding portion in the optical axis direction included in the drive source attached to the first frame is disposed.

[0133] (Technology 6) The light-shielding unit according to the sixth technique is the light-shielding unit according to the fifth technique, The recessed portion abuts against the optical axis direction protruding portion at both ends thereof, thereby defining the range of relative rotation between the first frame body and the second frame body. (Technology 7) The light-shielding unit according to the seventh technique is a light-shielding unit according to any one of the first to sixth techniques, The second frame body is engaged with the first frame body in a state where it is substantially immobile in the optical axis direction, and the multiple movable blades are driven to open and close in a gap formed between the first frame body and the second frame body, with their movement in the optical axis direction restricted.

[0134] (Technology 8) The light-shielding unit according to the eighth technology is a light-shielding unit according to any one of the first to seventh technologies, The second frame is engaged with the first frame on the outer circumferential side of the first main body portion or the second main body portion.

[0135] (Technology 9) The shading unit according to the ninth technique is a shading unit according to any one of the first to eighth techniques, The second frame is engaged with the first frame at a position radially outward of one or more of the plurality of movable blades about the optical axis.

[0136] (Technology 10) The light-shielding unit according to the tenth technique is the light-shielding unit according to the eighth or ninth technique, The second frame is engaged with the first frame by a bayonet connection. (Technology 11) The light-shielding unit according to the eleventh aspect of the present invention is the light-shielding unit according to the tenth aspect of the present invention, The engagement length between the first frame and the second frame, which are engaged with each other by the bayonet coupling, is minimum when the movable blades are fully open (open, maximum opening) and maximum when the movable blades are in the minimum aperture state.

[0137] (Technology 12) The light-shielding unit according to the technology 12 is the light-shielding unit according to the technology 11, When the first frame body is rotated relative to the second frame body in a direction in which the engagement length of the bayonet coupling becomes even shorter from the position where the engagement length is at its minimum, the rotational drive transmission unit restricts the rotation of the first frame body at a position just before the engagement length becomes zero.

[0138] (Technology 13) A light-shielding unit according to a thirteenth aspect of the present invention is a light-shielding unit according to any one of the first to twelfth aspects of the present invention, a rotation shaft disposed on any one of the first frame, the second frame, and the movable blade, for driving the movable blade to rotate; a cam follower disposed on any one of the first frame, the second frame, and the movable blade, for driving the movable blade to rotate; a cam groove disposed on one of the first frame, the second frame, and the movable blade for driving the movable blade to rotate; Furthermore, When viewed from the optical axis direction, the rotation shaft, the cam follower, and the cam groove are arranged to overlap with the second frame.

[0139] (Technology 14) A light-shielding unit according to a fourteenth aspect of the present invention is a light-shielding unit according to any one of the first to thirteenth aspects of the present invention, The one or more rotational drive transmitters are arranged so as to overlap with the second frame body when viewed from the optical axis direction.

[0140] (Technology 15) A light-shielding unit according to a fifteenth aspect of the present invention is a light-shielding unit according to any one of the first to fourteenth aspects of the present invention, A part or all of the first frame body constitutes one outer shape in the optical axis direction, and a part or all of the second frame body constitutes the other outer shape in the optical axis direction.

[0141] (Technology 16) The lens barrel according to Technology 16 is A shading unit according to any one of techniques 1 to 15; one or more lenses that guide the light incident on the light blocking unit in a desired direction; It is equipped with:

[0142] (Technology 17) A lens barrel according to Technology 17 is the lens barrel according to Technology 16, The light blocking unit is an aperture unit that adjusts the amount of light that passes through one or more of the lenses. (Technology 18) The shading unit according to Technology 18 is a first frame body having a substantially annular first main body portion and a first opening provided in a central portion of the first main body portion and allowing light to pass along an optical axis direction; a second main body portion having a substantially circular ring shape; a second opening provided in a central portion of the second main body portion and allowing light to pass along the optical axis direction; and a second frame body engaged with the first frame body in a state in which the second frame body can rotate around the optical axis. a drive source held by the first frame and configured to rotate the second frame relative to the first frame around the optical axis; a plurality of movable blades, at least a portion of which is disposed in a space formed between the first frame body and the second frame body, which form a third opening through which the light that has passed through the first opening or the second opening passes, which are driven to open and close when the second frame body is rotated relative to the first frame body by the drive source, and which change the size of the third opening by the opening and closing operation to adjust the amount of light that passes through; Equipped with A part or all of the first frame body constitutes one outer shape in the optical axis direction, and a part or all of the second frame body constitutes the other outer shape in the optical axis direction.

[0143] (Technology 19) The light-shielding unit according to Technology 19 is the light-shielding unit according to Technology 18, The second frame body is engaged with the first frame body in a state where it is substantially immobile in the optical axis direction, and the multiple movable blades are driven to open and close in a gap formed between the first frame body and the second frame body, with their movement in the optical axis direction restricted.

[0144] (Technology 20) The light-shielding unit according to the technology 20 is the light-shielding unit according to the technology 19, The second frame is engaged with the first frame on the outer circumferential side of the first main body portion or the second main body portion. (Technology 21) The light-shielding unit according to the technology 21 is the light-shielding unit according to the technology 18, The second frame is engaged with the first frame at a position radially outward of one or more of the plurality of movable blades about the optical axis.

[0145] (Technology 22) The light-shielding unit according to the technology 22 is a light-shielding unit according to any one of the technologies 18 to 21, The second frame is engaged with the first frame by a bayonet connection. (Technology 23) The shading unit according to the technology 23 is a shading unit according to any one of the technologies 18 to 22, a rotation shaft disposed on any one of the first frame, the second frame, and the movable blade, for driving the movable blade to rotate; a cam follower disposed on any one of the first frame, the second frame, and the movable blade, for driving the movable blade to rotate; a cam groove disposed on one of the first frame, the second frame, and the movable blade for driving the movable blade to rotate; Furthermore, When viewed from the optical axis direction, the rotation shaft, the cam follower, and the cam groove are arranged to overlap with the second frame body. (Technology 24) The lens barrel according to Technology 24 is A shading unit according to any one of techniques 18 to 23; one or more lenses that guide the light incident on the light blocking unit in a desired direction; It is equipped with:

[0146] (Technology 25) The lens barrel according to Technology 25 is the lens barrel according to Technology 24, The light blocking unit is an aperture unit that adjusts the amount of light that passes through one or more of the lenses. [Industrial Applicability]

[0147] The shading unit of the present disclosure has the effect of suppressing an increase in size in the optical axis direction, reducing the number of parts, and thereby reducing costs, and is therefore widely applicable to various devices such as optical equipment equipped with a shading unit. [Explanation of symbols]

[0148] 10 Lens barrel 11 1st group unit 11a Campin 11b Straight protrusion 12 2nd group unit 12a Main body 12b Lens holder 12c straight groove 12d bayonet rib 13 3rd group unit 13a Campin 14 Cam frame 14a Cam groove 14b Cam groove 14c bayonet groove 15 Straight Frame 15a straight groove 20 Aperture unit (light blocking unit) 21 Main plate (first frame) 21a main body portion (first main body portion) 21b opening (1st opening) 21c Mounting part 21ca through hole 21d Claw part 21e Groove 21f Rotation axis 22 Drive ring (second frame) 22a Main body (second main body) 22b opening (second opening) 22c Gear part (rotating connection part) 22da insertion part 22db locking part 22dc outer wall 22dd bayonet groove 22e Groove 22f Cam follower 22g recess 22ga side wall (first mechanical end) 22gb Side wall (end of second mechanism) 23 Aperture blades (movable blades) 23a Wing 23b opening (3rd opening) 23c through hole 23d Cam slot 24 Drive motor (drive source) 24a Drive gear (rotational drive transmission part) A1 Locking part (minimum) A2 Locking part (maximum) L1~L3 1st to 3rd lenses (lens group) X optical axis

Claims

1. a first frame body having a substantially annular first main body portion and a first opening provided in a central portion of the first main body portion and allowing light to pass along an optical axis direction; a second frame body having a substantially annular second main body portion, a second opening provided in a central portion of the second main body portion and allowing light to pass along the optical axis direction, and a rotary connection portion provided on the second main body portion, and engaging with the first frame body in a state rotatable about the optical axis; a drive source held by the first frame and configured to rotate the second frame relative to the first frame around the optical axis; one or more rotational drive transmission units that transmit rotation or a rotational drive force transmitted from the drive source to the rotation connection unit; a plurality of movable blades, at least a portion of which is disposed in a space formed between the first frame and the second frame, which form a third opening through which the light that has passed through the first opening or the second opening passes, which are driven to open and close when the second frame is rotated relative to the first frame by the drive source, and which change the size of the third opening by the opening and closing operation to adjust the amount of light that passes through; A shading unit comprising:

2. The rotational connection portion is provided on the outer circumferential side of the second frame. The light-shielding unit according to claim 1 .

3. the rotational connection portion and one or more members of the one or more rotational drive transmission portions are arranged to engage with each other radially outward of one or more of the plurality of movable blades about the optical axis; The light-shielding unit according to claim 1 .

4. the one or more rotational drive transmission units are configured by gears that rotate in conjunction with the drive source, and the rotational connection unit is configured by a gear provided on the outer periphery of the second frame body; The light-shielding unit according to any one of claims 1 to 3.

5. the second frame further has a recess in the optical axis direction in which a protruding portion in the optical axis direction included in the driving source attached to the first frame is disposed. The light-shielding unit according to any one of claims 1 to 3.

6. the recess defines a range of relative rotation between the first frame and the second frame by abutting the optical axis direction protruding portion at both ends thereof; The light-shielding unit according to claim 5 .

7. the second frame is engaged with the first frame in a state of being substantially immobile in the optical axis direction, and the plurality of movable blades are driven to open and close while their movement in the optical axis direction is restricted in a gap formed between the first frame and the second frame. The light-shielding unit according to any one of claims 1 to 3.

8. the second frame is engaged with the first frame at an outer peripheral side of the first main body portion or the second main body portion; The light-shielding unit according to any one of claims 1 to 3.

9. the second frame is engaged with the first frame at a position radially outward of one or more of the plurality of movable blades about the optical axis; The light-shielding unit according to any one of claims 1 to 3.

10. The second frame body is engaged with the first frame body by a bayonet coupling. The light-shielding unit according to claim 8 or 9.

11. an engagement length between the first frame body and the second frame body that are engaged with each other by the bayonet coupling is minimum when the movable blades are in a fully opened state, and is maximum when the movable blades are in a minimum throttle state; The light blocking unit according to claim 10.

12. When the first frame body is rotated relative to the second frame body in a direction in which the engagement length of the bayonet coupling becomes further shorter from a position where the engagement length is minimum, the rotation drive transmission unit restricts the rotation of the first frame body at a position just before the engagement length becomes zero. The shading unit according to claim 11.

13. a rotation shaft disposed on any one of the first frame, the second frame, and the movable blade for rotating the movable blade; a cam follower disposed on any one of the first frame, the second frame, and the movable blade for driving the movable blade to rotate; a cam groove disposed on one of the first frame, the second frame, and the movable blade for rotationally driving the movable blade; Furthermore, When viewed from the optical axis direction, the rotation shaft, the cam follower, and the cam groove are arranged to overlap with the second frame body. The light-shielding unit according to any one of claims 1 to 3.

14. the one or more rotational drive transmission units are arranged to overlap with the second frame body when viewed from the optical axis direction; The light-shielding unit according to any one of claims 1 to 3.

15. A part or all of the first frame body constitutes one outer shape in the optical axis direction, and a part or all of the second frame body constitutes the other outer shape in the optical axis direction. The light-shielding unit according to any one of claims 1 to 3.

16. The light blocking unit according to any one of claims 1 to 3, one or more lenses that guide the light incident on the light blocking unit in a desired direction; A lens barrel comprising:

17. the light blocking unit is an aperture unit that adjusts the amount of light that passes through one or more of the lenses; The lens barrel according to claim 16.

18. a first frame body having a substantially annular first main body portion and a first opening provided in a central portion of the first main body portion and allowing light to pass along an optical axis direction; a second main body portion having a substantially annular shape; a second opening provided in a central portion of the second main body portion and allowing light to pass along the optical axis direction; and a second frame body engaged with the first frame body in a state rotatable about the optical axis; a drive source held by the first frame and configured to rotate the second frame relative to the first frame around the optical axis; a plurality of movable blades, at least a portion of which is disposed in a space formed between the first frame and the second frame, which form a third opening through which the light that has passed through the first opening or the second opening passes, which are driven to open and close when the second frame is rotated relative to the first frame by the drive source, and which change the size of the third opening by the opening and closing operation to adjust the amount of light that passes through; Equipped with A light-blocking unit in which a part or all of the first frame body constitutes one outer shape in the optical axis direction, and a part or all of the second frame body constitutes the other outer shape in the optical axis direction.

19. the second frame is engaged with the first frame in a state of being substantially immobile in the optical axis direction, and the plurality of movable blades are driven to open and close while their movement in the optical axis direction is restricted in a gap formed between the first frame and the second frame. The shading unit according to claim 18.

20. the second frame is engaged with the first frame at an outer peripheral side of the first main body portion or the second main body portion; 20. The shading unit according to claim 19.

21. the second frame is engaged with the first frame at a position radially outward of one or more of the plurality of movable blades about the optical axis; The shading unit according to claim 18.

22. The second frame body is engaged with the first frame body by a bayonet coupling.

22. A shading unit according to any one of claims 18 to 21.

23. a rotation shaft disposed on any one of the first frame, the second frame, and the movable blade for rotating the movable blade; a cam follower disposed on any one of the first frame, the second frame, and the movable blade for driving the movable blade to rotate; a cam groove disposed on one of the first frame, the second frame, and the movable blade for rotationally driving the movable blade; Furthermore, When viewed from the optical axis direction, the rotation shaft, the cam follower, and the cam groove are arranged to overlap with the second frame body.

22. A shading unit according to any one of claims 18 to 21.

24. a shading unit according to any one of claims 18 to 21; one or more lenses that guide the light incident on the light blocking unit in a desired direction; A lens barrel comprising:

25. the light blocking unit is an aperture unit that adjusts the amount of light that passes through one or more of the lenses; 25. The lens barrel according to claim 24.

Images