Light quantity control device and optical equipment

Abstract

To provide a light quantity adjustment device that maintains a circular shape of a diaphragm aperture from an open state to a small aperture state.SOLUTION: A light quantity adjustment device of the present invention comprises: a plurality of diaphragm blades 5 that is annularly arranged around a light passage path and comes in and out of the light passage path; and a driving member 4 that drives the diaphragm blades 5. The diaphragm blades 5 each have a root part 5d that is arranged with an engagement part engaged with the driving member 4, an inner edge part 5r that forms the diaphragm aperture, and a leading end part 5t that is an opposite end of the root part 5d. The inner edge part 5r of the diaphragm blade 5 is formed of an edge part whose radius of curvature is gradually reduced from the root part 5d side toward the leading end part 5t, and in a process in which the driving member drives, and thereby the diaphragm aperture is changed from an open state to a small aperture state, at an end part of the inner edge part 5r closer to the leading end part, a state in which the radius of curvature is smaller than the radius of curvature at an end part of the inner edge part closer to the root part side, makes continuous transition.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a light amount adjustment device, such as a diaphragm device, and an optical apparatus equipped with the same. [Background technology]

[0002] The shape of the aperture as a light passing opening formed in the aperture device is preferably as close to circular as possible, and in order to form an aperture close to a circle, three or more aperture blades (light amount adjustment blades) are often used. A polygonal aperture close to a circle is formed by rotating the multiple aperture blades using a drive ring that can rotate around a fixed opening formed in a base member (aperture forming member).

[0003] Here, Patent Document 1 discloses an aperture device having an arc on the inner edge of an aperture blade that forms a full aperture and a specific aperture. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 4-128727 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while the aperture device of Patent Document 1 was able to make the aperture circular at the full aperture and the specific aperture, there was a problem that at other apertures, the aperture became non-circular, i.e., polygonal. [Means for solving the problem]

[0006] In order to solve the above problems, a light amount adjustment device of the present invention includes a plurality of diaphragm blades that are arranged in an annular shape around a light passage and move in and out of the light passage, and a drive member that drives the diaphragm blades, and the diaphragm blades have a base portion at which an engagement portion that engages with the drive member is arranged, an inner edge portion that forms an aperture, and a tip portion at an end opposite to the base portion, and the inner edge portion of the diaphragm blade is formed of an edge portion whose radius of curvature gradually decreases from the base portion side toward the tip portion, and the diaphragm aperture is changed from an open state to a closed state by driving the drive member. Minimum aperture In the process of changing to the minimum aperture, in each aperture shape from the intermediate aperture between the open state and the minimum aperture, Overlaps adjacent aperture blades in a counterclockwise direction the end portion on the tip side and the inner edge portion Overlaps adjacent blades in clockwise direction the end portion on the base portion side forms each of the aperture opening shapes, The aperture opening shapes are continuously transitioned such that a radius of curvature of a first end portion on the tip side forming a certain aperture shape among the aperture opening shapes is smaller than a radius of curvature of a first end portion on the root side forming the certain aperture shape, a radius of curvature of a second end portion on the tip side forming another aperture shape that is the next smallest aperture shape after the certain aperture shape is smaller than a radius of curvature of a second end portion on the root side forming the other aperture shape, and the radius of curvature of the second end portion on the tip side is smaller than the radius of curvature of the first end portion on the tip side, and the radius of curvature of the second end portion on the root side is smaller than the radius of curvature of the first end portion on the root side. It is characterized by:

[0007] Further, a light amount adjustment device of the present invention includes a plurality of diaphragm blades that are arranged in an annular shape around a light passage and move in and out of the light passage, and a drive member that drives the diaphragm blades, wherein the diaphragm blades have a base portion having an engagement portion that engages with the drive member, an inner edge portion that forms an aperture, and a tip portion at the end opposite to the base portion, and the inner edge portion of the diaphragm blade is formed by an edge portion whose radius of curvature gradually decreases from the base portion side toward the tip portion and an edge portion that connects the radii of curvature by a tangent, and during the process in which the diaphragm opening changes from an open state to a small aperture state by driving the drive member, For each aperture shape from the intermediate aperture between the maximum aperture and the minimum aperture, The end portion of the inner edge portion on the tip end side and an end portion of the inner edge portion on the base side forms each of the aperture opening shapes, and an end portion on the tip side or the radius of curvature of the inscribed circle at the end on the tip side is ,before The present invention is characterized in that the radius of curvature of the inner edge of the end portion on the base portion side or the radius of curvature of the inscribed circle of the end portion on the base portion side continuously changes. Effect of the Invention

[0008] According to the present invention, it is possible to provide a light amount adjusting device in which the aperture opening is nearly circular from the fully opened state to the smallest aperture state. [Brief description of the drawings]

[0009] [Figure 1] 1 is an exploded perspective view of a light amount adjustment device according to a first embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] Front view of the aperture blades. [Diagram 5] FIG. 4 is a diagram showing a change in the opening diameter in the first embodiment. [Figure 6] FIG. 4 is an enlarged view showing a change in the opening diameter in the first embodiment. [Figure 7] Detailed view of the opening diameter. [Figure 8] Movement of the aperture blades. [Figure 9] FIG. 11 is a front view of an aperture leaf according to a second embodiment. [Figure 10A] FIG. 13 is a diagram showing a change in the opening diameter in the second embodiment (enlarged view of the opening state in (A)). [Figure 10B] FIG. 13 is a diagram showing a change in the opening diameter in the second embodiment (enlarged view of the opening state in (B)). [Figure 10C] FIG. 13 is a diagram showing a change in the opening diameter in the second embodiment (enlarged view of the opening state in (C)). [Figure 10D] FIG. 13 is a diagram showing a change in the opening diameter in the second embodiment (enlarged view of the opening state in (D)). [Figure 10E] FIG. 13 is a diagram showing a change in the opening diameter in the second embodiment (enlarged view of the opening state in (E)). [Figure 11] 1 is a schematic diagram of an optical apparatus equipped with a diaphragm device according to a first or second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0011] <First embodiment> 1(A) and (B) are exploded perspective views of an aperture device 100 which is a first embodiment of a light amount adjusting device of the present invention. Fig. 2 is a perspective view of the light amount adjusting device.

[0012] In FIG. 1, a base member 2 (aperture forming member) that serves as the base of the diaphragm device 100 has an opening 2a in the center that allows light to pass through in accordance with the optical path of the lens. A plurality of engagement portions 2b are arranged on the outside of the opening 2a. The engagement portions 2b may be straight grooves or curved grooves. The base member 2 is produced by molding a resin. A drive unit 1 using, for example, a stepping motor, a galvanometer, or the like is attached to the base member 2, and a pinion gear 3 is attached to the rotation shaft of the drive unit 1.

[0013] The driving ring 4, which drives the aperture blades described below, has an inner engagement portion 4a, an engagement portion 4b, and a driven portion 4e. The engagement portion 4b may be a straight groove or a curved groove. The driving ring 4 is produced by molding a resin, but may also be produced by pressing a resin film (such as a PET sheet material), for example.

[0014] The inner engagement portion 4a of the drive ring 4 engages with the opening 2a (outer engagement portion) of the base member 2. The opening 2a (outer engagement portion) of the base member 2, which rotatably holds the drive ring 4, is formed in a circular shape that serves as the center of rotation. In addition, in FIG. 1, the opening 2a (outer engagement portion) of the base member 2 is formed in a continuous circumferential shape, but it may be formed of multiple protrusions so as to engage with the inner engagement portion 4a of the drive ring 4 in a circumferential shape.

[0015] In the first embodiment, the drive ring 4 is engaged with the outside of the outer engagement portion 2a of the base member 2, but it is also possible to form an outer engagement portion on the drive ring 4 and an inner engagement portion on the base member 2, and to engage the drive ring 4 with the inside of the base member 2.

[0016] In addition, a gear portion serving as the driven portion 4e is formed on the driving ring 4. The driven portion 4e meshes with the pinion gear 3, and the rotational force generated in the driving portion 1 is transmitted from the pinion gear 3 to the driven portion 4e, causing the driving ring 4 to rotate.

[0017] An aperture blade group 50 is disposed above the drive ring 4. In addition, the aperture blade group is composed of nine blades as described below, but the number of blades may be any number as long as it is composed of a plurality of aperture blades.

[0018] The aperture blade group 50 is composed of a plurality of aperture blades 5. In this embodiment, nine aperture blades 5 are arranged around the opening 2a in a ring shape with the front and back overlapping each other and the tips woven in one direction to form the aperture blade group 50. Fig. 3 is a perspective view showing the shape of one aperture blade 5. Fig. 4 is a front view showing the shape of one aperture blade 5.

[0019] The diaphragm blade 5 has a first driving pin 5b, a second driving pin 5c, and an opening forming portion 5r. In addition, in the diaphragm blade 5, the side where the first driving pin 5b and the second driving pin 5c are arranged is referred to as a root portion 5d, and the end opposite to the root portion 5d is referred to as a tip portion 5t.

[0020] The opening forming portion (inner edge portion) 5r is formed so that the curvature gradually decreases from the root portion 5d side toward the tip portion 5t. For example, when the opening forming portion 5r on the side closer to the root portion 5d is the opening forming portion r1, and the opening forming portions r2, r3, . . . , r11, r12 are arranged toward the tip portion 5t, the radius of curvature is r1>r2>r3>. . . >r11>r12. In addition, an opening forming auxiliary portion r99 may be provided between the opening forming portion r12 and the tip portion 5t. The radius of curvature of the opening forming auxiliary portion r99 may be larger than r12, or may be a straight line. It is desirable that the opening forming auxiliary portion r99 has a shape that does not collapse the opening shape at the minimum aperture. In addition, the opening forming portion 5r may be formed so that the curvature decreases toward the tip side by a spline curve or the like.

[0021] The diaphragm blades 5 may be made by, for example, pressing a PET sheet material or the like to create a blade portion, and fixing a drive pin by caulking, molding, adhesive, or the like. The diaphragm blades 5 may also be made of a molded product. It is desirable that the diaphragm blades 5 are subjected to light-shielding treatment, anti-reflection treatment, sliding treatment, and the like.

[0022] A cover member 6 (aperture forming member) with an opening 6a formed in the center is disposed above the diaphragm blade group 50. A plurality of engagement portions 6c are disposed on the outside of the opening 6a. The engagement portions 6c may be straight grooves or curved grooves. In the space formed by the base member 2 and the cover member 6, the drive ring 4 and the diaphragm blade group 50 are driven.

[0023] The first drive pin 5b of the diaphragm blade 5 engages with the engagement portion 2b of the base member 2 and the engagement portion 4b of the drive ring 4. The second drive pin 5c of the diaphragm blade 5 engages with the engagement portion 6c of the cover member 6. The pinion gear 3 rotates, and a driving force is transmitted to the driven portion 4e of the drive ring 4, causing the drive ring 4 to rotate. When the drive ring 4 rotates, a driving force is applied from the engagement portion 4b of the drive ring 4 to the first drive pin 5b of the diaphragm blade 5, and the diaphragm blade 5 moves in and out of the opening 2a of the base member 2. In other words, it moves in and out of the optical path that passes through the opening 2a. The diaphragm blade group 50 forms the diaphragm opening shape from the fully open to the minimum aperture by the opening forming portion 5r.

[0024] In this embodiment, the driving force of the driving unit 1 is the driving source, but the driving ring 4 may be rotated manually. Furthermore, in this embodiment, the driving force of the driving unit 1 is transmitted to the driving ring 4 by the pinion gear 3, but the driving force may be transmitted by attaching an arm member having a driving pin to the driving unit 1 and providing an engagement groove in the driving ring 4 that engages with the driving pin.

[0025] Figure 5 shows the aperture shape in this embodiment with the cover member 6 removed. The aperture shapes are shown as (A), (B), (C), (D), and (E) in order of decreasing aperture diameter. Since there are multiple aperture blades 5, for the sake of explanation, they are respectively described as aperture blade 5(1), aperture blade 5(2), .... Figure 6 shows an enlarged view of Figure 5.

[0026] 5(A) and 6(A) show a first aperture shape. The aperture shape in (A) is formed by aperture forming portions r4, r5, r6, and r7 of the aperture blade group 50. For the sake of explanation, the aperture blade 5(1) is shown as a representative of the multiple aperture blades 5. (B) shows a second aperture shape. The aperture shape in (B) is formed by aperture forming portions r5, r6, r7, and r8. (C) shows a third aperture shape. The aperture shape in (C) is formed by aperture forming portions r6, r7, r8, r9, r10, and r11. (D) shows a fourth aperture shape. The aperture shape in (D) is formed by aperture forming portions r9, r10, r11, and r12. (E) shows a fifth aperture shape. The aperture shape in (E) is formed by aperture forming portions r10, r11, r12, and r99. In this process of changing in the smaller aperture direction from (A) to (E), the aperture shape is formed by the use range of the aperture forming portion R of the aperture blade 5 that forms the aperture shape gradually shifting from the base portion 5d side to the tip side 5t. Because the aperture shape can be formed by the aperture forming portion with a curvature radius close to the aperture diameter, it is possible to form an aperture shape that is extremely close to circular over the entire aperture adjustment range.

[0027] The details of the aperture shape of the present embodiment 1 will be described with reference to FIG. 7 as a representative example. FIG. 7 is an enlarged view of the aperture shape (D). In order to make the aperture shape extremely close to a circle throughout the entire aperture adjustment range, the radius of curvature of the aperture forming portion 5r is gradually reduced toward the tip. Here, among the intersections between the aperture forming portions 5r of each aperture blade 5, the intersection on the root portion 5d side of the aperture blade 5(1) is called the intersection 5rd(1), and the intersection on the tip portion 5t side is called the intersection 5rt(1). Among the aperture forming portions 5r, the middle point between the intersections 5rd(1) and 5rt(1) is called 5rm(1). In the process of changing from the fully open aperture to the minimum aperture, the intersections 5rd(1), 5rt(1), and the middle point 5rm(1) are gradually shifted toward the tip portion 5t side of the aperture blade 5(1), so that an aperture forming portion with a radius of curvature close to the desired aperture diameter can be used continuously throughout the entire aperture adjustment range. Therefore, an aperture shape extremely close to a circle can be formed throughout the entire aperture adjustment range. The radius of curvature of the opening forming portion at the intersection point 5rd(1) continues to be greater than the radius of curvature of the opening forming portion at the intersection point 5rt(1).

[0028] In addition, in the aperture shape, the point of contact between the inscribed circle of the aperture shape and the aperture forming portion 5r is r5 in the state of Fig. 6(A), the point of contact is r6 in the state of Fig. 6(B), the point of contact is r8 in the state of Fig. 6(C), the point of contact is r10 in the state of Fig. 6(D), and the point of contact is r12 in the state of Fig. 6(E). In other words, in the process of changing from fully open to the minimum aperture, by gradually shifting the point of contact between the inscribed circle of the aperture shape and the aperture forming portion 5r from the aperture forming portion 5r on the base portion 5d side of the aperture blade 5 to the tip portion 5t side, it is possible to continuously use an aperture forming portion with a curvature radius close to the desired aperture diameter, and therefore it is possible to form an aperture shape that is extremely close to a circle over the entire aperture adjustment range.

[0029] Here, the movement of the aperture forming portion 5r of the aperture blade 5 gradually moving from the base portion 5d side to the tip portion 5t in the process of changing the aperture shape from (A) to (E) in the small aperture direction according to the configuration of this embodiment will be described. FIG. 8 shows the movement of the aperture blade 5. The first drive pin 5b of the aperture blade 5 engages with the engagement portion 4b of the drive ring 4 and the engagement portion 2b of the base member 2. The second drive pin 5c of the aperture blade 5 is not shown in FIG. 8 and engages with the engagement portion 6c of the cover member 6 shown in FIG. 1 and the like. When the drive ring 4 rotates, a driving force is applied to the first drive pin 5b of the aperture blade 5, and the aperture blade 5 moves. The first drive pin 5b of the aperture blade 5 is guided by the engagement portion 2b of the base member 2, and while rotating around the opening 2a of the base member 2, the first drive pin 5b moves in a direction away from the opening 2a. Due to this movement, as the aperture shape changes to a smaller aperture, the range of use of the aperture forming portion 5r of the aperture blade 5 can be gradually shifted toward the tip portion 5t. The size of the aperture shape can be adjusted by the shape of the engagement portion 6c of the cover member 6.

[0030] <Second embodiment> 9 is an enlarged view of the aperture blade of the aperture device of the second embodiment. The second embodiment is an embodiment in which the shape of the aperture blade is changed from that of the first embodiment. The aperture blade 5 of the second embodiment has an aperture forming portion in which the aperture forming portions r3, r4, r5, r6, r7, r8, r9, r10, r11, and r12 are connected by tangent lines compared to the aperture blade 5 of the first embodiment. Therefore, it is easy to eliminate a convex portion that occurs when, for example, the aperture forming portion r3 and the aperture forming portion r4, which have different radii of curvature, are directly connected.

[0031] 10 is an enlarged view of the aperture shape in the second embodiment. The aperture shapes are represented as (A), (B), (C), (D), and (E) in order of increasing aperture diameter. Of the intersections between the aperture forming portions 5r of each aperture blade 5, the intersection on the root portion 5d side of the aperture blade 5(1) is referred to as the intersection 5rd(1), and the intersection on the tip portion 5t side is referred to as the intersection 5rt(1). Of the aperture forming portions 5r, the midpoint between the intersection 5rd(1) and the intersection 5rt(1) is referred to as the intersection 5rm(1).

[0032] In the process of changing from fully open to the minimum aperture, the intersection 5rd(1) of the aperture blade 5(1) is the intersection of the aperture forming portion r4 at aperture aperture (A), the tangent of the aperture forming portions r4 and r5 at aperture aperture (B), the aperture forming portion r6 at aperture aperture (C), the aperture forming portion r8 at aperture aperture (D), and the aperture forming portion r10 at aperture aperture (E) with the aperture forming portion of the adjacent aperture blade. In other words, the intersection 5rd(1) gradually shifts from the aperture forming portion on the base portion 5d side of the aperture blade 5(1) to the aperture forming portion on the tip portion 5t side.

[0033] In addition, in the process of changing from fully open to the minimum aperture, the intersection 5rt(1) of the aperture blade 5(1) is the intersection of the aperture forming portion r7 at aperture opening (A), the tangent of the aperture forming portions r8 and r9 at aperture opening (B), the tangent of the aperture forming portions r11 and r12 at aperture opening (C), the aperture forming portion r12 at aperture opening (D), and the aperture forming portion r99 with the aperture forming portion of the adjacent aperture blade at aperture opening (E). In other words, the intersection 5rt(1) gradually shifts from the aperture forming portion on the root portion 5d side of the aperture blade 5(1) to the aperture forming portion on the tip portion 5t side.

[0034] In addition, in the process of changing from fully open to the minimum aperture, point 5rm(1) of aperture blade 5(1) is located at aperture formation portion r5 at aperture (A), aperture formation portion r6 at aperture (B), a tangent to aperture formation portions r8 and r9 at aperture (C), aperture formation portion r11 at aperture (D), and aperture formation portion r12 at aperture (E). In other words, intersection 5rt(1) gradually transitions from the aperture formation portion on the base portion 5d side of aperture blade 5(1) to the aperture formation portion on the tip portion 5t side.

[0035] By gradually shifting the intersection points 5rd(1), 5rt(1) and the midpoint 5rm(1) to the tip 5t of the aperture blade 5(1), it is possible to continuously use aperture forming portions (including tangents connecting the radii of curvature) with a radius of curvature close to the desired aperture diameter, so that an aperture shape that is extremely close to a circle can be formed over the entire aperture adjustment range. The radius of curvature of the aperture forming portion at the intersection point 5rd(1) continues to be larger than the radius of curvature of the aperture forming portion at the intersection point 5rt(1).

[0036] In addition, in the aperture shape, the point of contact between the inscribed circle of the aperture shape and the aperture forming portion 5r is at r5 in the state of Fig. 10(A), the point of contact is at the tangent line between r6 and r7 in the state of Fig. 10(B), the point of contact is at the tangent line between r8 and r9 in the state of Fig. 10(C), the point of contact is at r11 in the state of Fig. 10(D), and the point of contact is at r12 in the state of Fig. 10(E). In other words, in the process of changing from fully open to the minimum aperture, the point of contact between the inscribed circle of the aperture shape and the aperture forming portion 5r gradually shifts from the aperture forming portion 5r on the base portion 5d side of the aperture blade 5 to the tip portion 5t, so that an aperture forming portion with a radius of curvature close to the desired aperture diameter can be used continuously, and an aperture shape that is extremely close to a circle can be formed over the entire aperture adjustment range.

[0037] <Third embodiment> FIG. 11 shows an interchangeable lens 221 for a single-lens reflex camera, which is an optical device equipped with any of the diaphragm devices described in the first and second embodiments, and the internal configuration of a camera body to which the interchangeable lens is attached.

[0038] The lens barrel of the interchangeable lens 221 contains a photographing optical system including a variable magnification lens 232, the aperture device 100 of the first or second embodiment that narrows the optical path, and a focus lens 229.

[0039] The image sensor 225, which is composed of a photoelectric conversion element such as a CCD sensor or a CMOS sensor, is disposed in the camera body and performs photoelectric conversion on the subject image formed by the interchangeable lens 221 to output an electrical signal. The brightness of the subject image formed on the image sensor 225 (i.e., the amount of light reaching the image sensor 225) can be appropriately set by changing the aperture of the diaphragm device 100 or by moving an ND filter (not shown) forward or backward.

[0040] The electrical signal output from the imaging element 225 is converted into a digital signal in the image processing circuit 226 and is subjected to various image processing, thereby generating an image signal.

[0041] A user can change the magnification (zooming) by moving a variable magnification lens 232 by rotating a zoom ring 231. The controller 222 detects the contrast of an image signal, controls a focus motor 228 in accordance with the contrast, and performs autofocus by moving a focus lens 229. Alternatively, the controller 222 may control the focus motor 228 and move a focus lens 229 based on a detection signal from a focus detection means using a phase difference detection method (not shown), to perform autofocus.

[0042] Furthermore, the controller 222 controls the driver 1 of the aperture device 100 to adjust the amount of light based on the photometric value of a photometric means (not shown) or an image signal. This makes it possible to make the blur and ghosting during shooting appear natural, and to record high-quality images.

[0043] The present invention is not limited to the single-lens reflex camera described above, but can also be widely applied to optical devices such as digital cameras with an integrated lens, video cameras, and the like.

[0044] As described above, according to the above embodiment, it is possible to realize a light amount adjustment device having a circular aperture over a wide range of aperture adjustment. [Explanation of symbols]

[0045] 1: Drive unit, 2: Base member (aperture forming member), 3: Pinion gear, 4: Drive ring, 5: Diaphragm blade, 5d: Base portion, 5t: Tip portion, 5r: Aperture forming portion (inner edge portion), 6: Cover member (aperture forming member)

Claims

1. A plurality of aperture blades are arranged annularly around the light passage and move in and out of the light passage; A drive member that drives the diaphragm blades, The aperture blade is a base portion having an engagement portion that engages with the driving member; an inner edge portion that forms an aperture; a tip portion at an end opposite to the base portion, The inner edge of the aperture blade is formed of an edge having a radius of curvature that gradually decreases from the base side toward the tip, and in the process in which the aperture changes from the open state to the minimum aperture as the driving member is driven, in each aperture shape from an intermediate aperture between the open state and the minimum aperture to the minimum aperture, an end portion of the inner edge on the tip side that overlaps with another aperture blade adjacent in the counterclockwise direction and an end portion of the inner edge on the base side that overlaps with another aperture blade adjacent in the clockwise direction form each aperture shape, and a first end portion on the tip side that forms a certain aperture shape among each aperture shape. a radius of curvature of a first end portion on the base portion side that forms the certain aperture shape is smaller than a radius of curvature of a first end portion on the base portion side that forms the certain aperture shape, a radius of curvature of a second end portion on the tip portion side that forms another aperture shape that is the next smallest aperture shape after the certain aperture shape is smaller than a radius of curvature of a second end portion on the base portion side that forms the other aperture shape, and the radius of curvature of the second end portion on the tip portion side is smaller than the radius of curvature of the first end portion on the tip portion side, and the radius of curvature of the second end portion on the base portion side is smaller than the radius of curvature of the first end portion on the base portion side.

2. 2. The light amount adjusting device according to claim 1, wherein a radius of curvature of an inner edge portion of the certain aperture opening shape at an intermediate position between the first end portion on the tip end side and the first end portion on the base end side is larger than a radius of curvature of the first end portion on the tip end side and smaller than a radius of curvature of the first end portion on the base end side.

3. the engagement portion of the diaphragm blade is a first drive pin and a second drive pin, The diaphragm blade is driven between a first holding member and a second holding member, the first holding member has a cam groove that guides the movement of the first drive pin, the second holding member has a cam groove that guides the movement of the second drive pin, The driving member has a cam groove facing in a direction away from the light passing opening, The light amount adjusting device according to claim 1, characterized in that the first drive pin of the aperture blade communicates with a cam groove of the drive member and a cam groove of the first holding member, receives force from the cam groove of the drive member, and moves while being guided by the cam groove of the first holding member.

4. a lens barrel that forms an optical path of light passing through the light passage path, and a plurality of lenses that are arranged in the lens barrel; An optical device comprising: a light amount adjusting device according to claim 1 disposed between the plurality of lenses.

Images