JP2014206650A - Light quantity adjusting device, optical instrument, and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light quantity adjusting device and an optical instrument equipped with the adjusting device which are capable of stable drive of blades and advantageous in downsizing.SOLUTION: A light quantity adjusting device has: a base member in which a fixed aperture through which light passes is formed; and a plurality of diaphragm blades which are partially overlapped in an optical axis direction to form an aperture opening that narrows the fixed aperture, and rotate with respect to the base member to change the aperture opening. The plurality of diaphragm blades includes: a plurality of first diaphragm blades in which a tip part out of each diaphragm blade, which is an end part on the opposite side from a rotation center side with respect to the base member, does not overlap the base member in the optical axis direction but a support part different from the rotation center side and the tip part overlaps the base member, at a minimum aperture state where at least the aperture opening is minimum; and a plurality of second diaphragm blades in which a tip part out of each diaphragm blade, which is an end part on the opposite side from the rotation center side with respect to the base member, overlaps the base member in the optical axis direction at least in the minimum aperture state. The second diaphragm blades overlap the first diaphragm blades at least on one side out of a side closer to the base member and the opposite side in the optical axis direction.

Description

  The present invention relates to a light amount adjusting device mounted on an optical apparatus such as an imaging device or an interchangeable lens.

  2. Description of the Related Art In a light amount adjusting device (aperture device) used for an imaging device or the like, an aperture opening through which light passes is formed by a plurality of blades. In Patent Document 1, an iris diaphragm that forms a polygonal diaphragm opening by moving (turning) a large number of diaphragm blades using a rotatable drive ring around a fixed opening formed in a base member. An apparatus is disclosed.

Japanese Utility Model Publication No. 2-48928

  However, the conventional iris diaphragm device has the following problems. FIG. 10 shows a configuration of an imaging apparatus including a conventional iris diaphragm apparatus. Reference numeral 101 denotes a base member of the diaphragm device, and reference numeral 103 denotes a drive ring that can rotate around a fixed opening of the base member 101. Reference numeral 106 denotes an actuator that rotates the drive ring 103. Reference numeral 105 denotes a plurality of aperture blades that are rotated by a drive ring 103 about a shaft portion (not shown) provided on the base member 101. Further, reference numeral 114 denotes a lens disposed adjacent to the aperture device, and reference numeral 113 denotes an image sensor that photoelectrically converts a subject image formed by a photographing optical system including the lens 114 and the aperture device.

  FIG. 10 shows a state where a plurality of aperture blades 105 are narrowed down to form a small aperture. As the aperture is narrowed down, the plurality of aperture blades 105 warp toward the lens 114 as their tips overlap each other. For this reason, in order to avoid the interference between the warped diaphragm blade 105 and the lens 114, it is necessary to secure in advance a retreat space h of the lens 14 with respect to the diaphragm device. As a result, the imaging device is increased in size.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a light amount adjusting device that can realize stable driving of blades and is advantageous for downsizing, and an optical apparatus including the same.

  The light quantity adjusting device according to the present invention includes a light passage opening forming member that forms an opening through which light passes, and a plurality of light quantity adjusting blades that rotate toward the inside of the opening. The blade includes a non-transverse rotating blade whose rear end portion in the rotation direction overlaps with an edge of the opening portion when the leading end portion in the rotation direction of the blade is located in the opening portion. The light passage opening forming member here includes a fixed opening forming member in which a fixed opening through which light passes is formed, or an annular driving member for rotating the plurality of light quantity adjusting blades.

  Further, the light amount adjusting device according to the present invention forms a diaphragm aperture that restricts the fixed aperture by partially overlapping with a base member in which a fixed aperture through which light passes is formed in the optical axis direction that is the light traveling direction. And a plurality of aperture blades that rotate with respect to the base member to change the aperture opening, and each of the aperture blades is at least in the minimum aperture state where the aperture aperture is minimum. The tip portion that is the end opposite to the rotation center side of the base member does not overlap the base member in the optical axis direction, and is supported separately from the rotation center side and the tip portion. A plurality of first diaphragm blades that overlap the base member at a portion, and at least in the minimum diaphragm state, a distal end portion that is an end portion of each diaphragm blade on the side opposite to the rotation center side with respect to the base member, optical axis A plurality of second diaphragm blades that overlap the base member in the direction, the second diaphragm blades with respect to the first diaphragm blades in the direction of the optical axis close to the base member and its It is characterized by overlapping on at least one of the opposite sides.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the light quantity adjustment apparatus which can implement | achieve the stable drive of a blade | wing and is advantageous for size reduction, and an optical apparatus provided with the same.

1 is an exploded perspective view of a diaphragm device that is a first embodiment of a light amount adjusting device of the present invention. FIG. The front view which shows the 2nd aperture blade in 1st Embodiment. The front view which shows the 1st aperture blade in 1st Embodiment. The front view which shows the minimum aperture state in 1st Embodiment. Sectional drawing of the imaging device carrying the aperture device of embodiment. The front view of the aperture_diaphragm | restriction apparatus which used all the aperture blades as the 2nd aperture blade. The front view which shows the fully closed state of the aperture_diaphragm | restriction apparatus in 1st Embodiment. The disassembled perspective view of the diaphragm | throttle device which is 2nd Embodiment of the light quantity adjustment apparatus of this invention. The disassembled perspective view of the diaphragm | throttle device which is 3rd Embodiment of the light quantity adjustment apparatus of this invention. Sectional drawing of the imaging device carrying the conventional aperture_diaphragm | restriction apparatus.

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

(First embodiment)
FIG. 1 is an exploded view of an iris diaphragm device that is a first embodiment of a light amount adjusting device of the present invention. 2 and 3 show a second diaphragm blade and a first diaphragm blade respectively used in the iris diaphragm device of the present embodiment. Further, FIG. 4 shows a state in which the minimum aperture A is formed by the first and second aperture blades.

  The diaphragm device according to the present embodiment creates a light passage path by a light passage opening forming member having an opening through which light passes, and adjusts the amount of light by a plurality of blades moving in the light passage path (opening). It becomes a device. Specifically, the diaphragm device includes a base member 1 (fixed opening forming member) in which a fixed opening 1a through which light passes is formed. That is, the base member 1 is one of the light passage opening forming members. The base member 1 includes a plurality of shaft portions 1d serving as rotation centers of a plurality of diaphragm blades (a plurality of first diaphragm blades 5 and a plurality of second diaphragm blades 4), which will be described in detail later, and a drive ring described later. And a guide 1e for guiding the rotation of 3. Hereinafter, the traveling direction of light passing through the aperture formed by the fixed aperture 1a and the plurality of aperture blades (light passing direction) is referred to as an optical axis direction.

  The blade driving unit 6 is configured by an actuator such as a stepping motor and is attached to the base member 1. A blade driving arm 2 is attached to the output shaft of the blade driving unit 6. The blade drive arm 2 is provided with a ring drive pin 2b.

  The drive ring 3 serving as an annular drive member includes a long hole portion 3b that engages with the ring drive pin 2b and a plurality of blade drive pins that rotate a plurality (eight in the present embodiment) of the diaphragm blades 4 and 5. 3c. Each of the plurality of blade driving pins 3c is engaged with a cam hole portion 4c formed at the base end portion of each of the four second diaphragm blades 4, and the remaining blade driving pins 3c are the remaining four sheets. The first aperture blades 5 are engaged with cam hole portions 5c formed at the respective base end portions. Hole portions 5d and 4d into which the shaft portion 1d of the base member 1 is inserted are formed at the base end portions of the first and second aperture blades 5 and 4, respectively. The drive ring 3 is constituted by an annular member surrounding the light passage path. That is, the drive ring 3 is one of the light passage opening forming members having the opening through which the light passes.

  The first and second aperture blades 5 and 4 partially overlap in the optical axis direction to limit the light passage aperture to form an aperture aperture. Here, in each diaphragm blade, a portion on the opposite side to the proximal end portion on the rotation center side is referred to as the distal end portions 5e and 4e, and a portion between the proximal end portion and the distal end portion is referred to as an intermediate portion. Further, in the first diaphragm blade 5, apart from the base end part and the distal end part 5e that are the center of rotation, a part that overlaps the base member at least in the minimum diaphragm state is referred to as a support part 5f. In other words, the first diaphragm blade 5 has the rear end portion 5f (rear end side) in the rotational direction when the front end portion 5e (the front end portion in the rotational direction) in the rotational direction of the blade is positioned within the light passage opening. It becomes a non-crossing type rotation blade which overlaps with a passage opening formation member (edge of an opening). In such a state where the non-transverse rotating blade is supported by rotation on the base end side, at least a part (the rear end portion in the rotation direction) other than the base end portion is light within the rotation operation range. It becomes a blade | wing with the shape which overlaps with the member (light passage opening formation member) which forms a passage opening. By including such a non-crossing type rotating blade, when another blade overlaps with this non-crossing type rotating blade, the adjacent blade is supported by the non-crossing type rotating blade, and stable driving as a whole is achieved. It becomes possible. On the other hand, the second aperture blade 4 is a transverse rotary drive blade that substantially crosses the light passage opening and substantially overlaps the light passage opening forming member (the edge of the opening).

  Here, for example, in the present embodiment, a plurality of non-transverse rotating blades and a plurality of transverse rotating blades are used in combination to form a light passage opening and adjust the light amount. At this time, a group of first diaphragm blades 5 that are a plurality of non-crossing rotary blades is defined as a first blade group, and a group of second diaphragm blades 4 that are a plurality of transverse rotary blades is a second. In the case of the blade group, for example, in the present embodiment, the first blade group overlaps the second blade group to realize a light amount adjustment structure. Thereby, the first blade group is substantially supported by the second blade group, and stable driving of the blade can be realized. In particular, in the present embodiment, the outer shape of the first diaphragm blade (non-transverse rotating blade) 5 is smaller than that of the second diaphragm blade (transverse rotating blade) 4. The first aperture blade 5 is substantially supported. Further, in the non-crossing type rotating blades constituting the first blade group, the rear end portion 5f in the rotating direction overlaps the edge portion of the opening portion when the leading end portion 5e in the rotating direction is located in the opening portion. Therefore, warpage of the blades themselves can be prevented, and stable driving can be realized even in the first blade group. For this reason, the total number of light quantity adjusting blades may be constituted by non-transverse rotating blades, whereby further miniaturization of the light quantity adjusting device can be realized. However, in consideration of stable driving of the blades, one or a plurality of transverse rotating blades may be included. Since the transverse rotary blade has a larger outer shape than the non-transverse rotary blade, there is an advantage in terms of stable driving of the overlapping blade groups. Further, in the case of configuring the light amount adjustment blade including blades other than the transverse rotation blade, stable driving may be ensured by using a non-rotation blade that does not rotate (straightly moving blade), Further, the light amount adjusting blade may be configured to include the non-transverse rotating blade and the transverse rotating blade described above. In the case of configuring the light amount adjusting blade including the non-rotating blade, the non-rotating blade is disposed between the transverse rotating blade and the non-crossing rotating blade so that the transverse rotating blade is arranged. It also serves as a partition member between the non-transverse rotating blades. As a result, further stable driving can be realized. Note that the non-rotating blades may be a single blade having a light passage opening or a pair of blades arranged to face each other in the blade movement direction. In the latter case, the light passage opening may be formed by the shape of the opposing ends of the pair of blades.

  By the way, in the present embodiment, when the blade driving arm 2 is rotated by the blade driving unit 6 and the driving ring 3 rotates, the blade driving pin 3c moves in the cam holes 5c and 4c while the first and second blades move. The diaphragm blades 5 and 4 are rotated about the shaft portion 1d. As a result, the aperture opening is formed with the largest amount of overlap between the open aperture opening formed by retracting all the aperture blades 4 and 5 out of the area of the fixed aperture 1a and all the aperture blades 4 and 5. And the amount of light passing through the aperture stop is adjusted. In the following description, a state in which an open aperture opening is formed is referred to as an open state, and a state in which a minimum aperture opening A is formed is referred to as a minimum aperture state.

  The partition plate 7 as a cover member has a fixed opening 7 a having the same diameter as the fixed opening 1 a of the base member 1. A drive ring 3 and aperture blades 4, 5 are sandwiched between the base plate 1 and the partition plate 7. The case 11 is fixed to the base member 1 with screws. That is, the partition plate 7 is one of the light passage opening forming members having an opening through which the light passes because the fixed opening 7a serves as a light passage path.

  Further, a filter holding plate 9 holding an ND filter 8 is disposed on the side opposite to the diaphragm blades 4 and 5 with respect to the partition plate 7. The filter holding plate 9 is driven to move in parallel by an ND arm 10 rotated by a filter driving unit (not shown), and is inserted into and removed from the aperture opening region. The ND filter 8 inserted in the area of the aperture opening attenuates light passing through the aperture opening. Thus, the amount of light passing through the aperture opening can be adjusted without narrowing down the aperture so that so-called small aperture diffraction occurs.

  The case 11 is fixed to the base member 1 together with the partition plate 7 by screws, with the filter holding plate 9 sandwiched between the case 11 and the partition plate 7.

  In the diaphragm device of the present embodiment, the second diaphragm blade 4 has the base member 1 in the middle portion as shown in FIG. 2 in all diaphragm states where a diaphragm aperture smaller than the open diaphragm aperture (fixed aperture 1a) is formed. The front end 4e overlaps the base member 1 in the optical axis direction. The partition plate 7 rotatably supports the tip portion 4 e of the second diaphragm blade 4 so as to be sandwiched between the base member 1. On the other hand, as shown in FIG. 3, the first aperture blade 5 does not cross the fixed opening 1a at least in the minimum aperture state, and the tip portion 5e does not overlap the base member 1 in the optical axis direction. As shown in FIG. 3, in the first diaphragm blade 5, at least in the minimum diaphragm state, the support portion 5f overlaps the base member.

  In the present embodiment, as shown in FIGS. 1 and 4, the second diaphragm blade 4 is disposed closer to the base member 1 in the optical axis direction than the plurality of first diaphragm blades 5. . For this reason, in the minimum aperture state in which at least most of the plurality of first aperture blades 5 overlap to form the minimum aperture aperture, the optical axis direction of the first aperture blade 5 by the intermediate portion of the second aperture blade 4 ( The first diaphragm blades 5 are pressed so as to limit the warp toward the base member 1 side. The effect of limiting the warpage can be obtained not only in the minimum diaphragm opening but also in a state where a diaphragm opening having a size in the vicinity thereof is formed. Therefore, as shown in FIG. 5, the warp of the first aperture blade 5 toward the base member 1 can be suppressed, and the aperture device can be made thinner.

  Since the second diaphragm blade 4 has a length that crosses the fixed opening 1 a provided in the base member 1, the length thereof is longer than that of the first diaphragm blade 5. For this reason, if all the eight diaphragm blades are the second diaphragm blades 4 as shown in FIG. 6, the overlapping of these diaphragm blades 4 becomes complicated, and the eight diaphragm blades are arranged as the arrangement space of the diaphragm blades 4. Minute thickness space is required. As a result, the thickness of the aperture device in the optical axis direction increases.

  On the other hand, when the first diaphragm blade 5 is also used as in the present embodiment, the first diaphragm blade 5 in the minimum diaphragm state shown in FIG. The leading end 5e of the diaphragm blade 5 can be brought closer to the partition plate 7 side. For this reason, it is not necessary to provide a space for eight diaphragm blades as an arrangement space in the thickness direction of the diaphragm blades. More specifically, the arrangement space in the thickness direction corresponding to the number of aperture blades overlapped in the open state (when retracted outside the area of the fixed aperture 1a of the aperture blades) is sufficient, so the aperture device thickness is reduced. be able to. Further, the first diaphragm blade 5 reduces the warpage of the diaphragm blade 5 in the optical axis direction (partition plate 7 side) because the support portion 5f overlaps the base member 1 in the diaphragm state where the minimum diaphragm aperture is formed. Therefore, the diaphragm device can be made thin. In addition, by providing the support portion 5f, the center of gravity of the first diaphragm blade 5 is not at the opening of the base member but at a position overlapping the base member. Can fall and warp.

  Further, assuming that all the diaphragm blades are the second diaphragm blades 4, as shown in FIG. 6, the clearance between the tip 4e of each diaphragm blade 4 and the other diaphragm blades 4 is equivalent to three diaphragm blades. The possibility of interference between the blades 4 increases. On the other hand, when the first diaphragm blade 5 is also used as in the present embodiment, the clearance between the tip 5e of the first diaphragm blade 5 and the other diaphragm blades is as shown in FIG. Since it becomes the number of sheets, the possibility of interference can be reduced.

  Further, even when all the eight diaphragm blades are used as the first diaphragm blade 5, since the support portion 5f overlaps the base member, warpage in the optical axis direction can be reduced, and the diaphragm device can be made thin. Can be realized.

  In the present embodiment, the tip 4e of the second diaphragm blade 4 overlaps the base member 1 in the optical axis direction in all diaphragm states in which a diaphragm aperture smaller than the open diaphragm aperture (fixed aperture 1a) is formed. Although the case has been described, it is sufficient that the tip portion 4e of the second aperture blade 4 overlaps the base member 1 at least in the minimum aperture state. Thereby, it is possible to obtain the effect of limiting the warp of the first aperture blade 5 at least in the minimum aperture state.

  Moreover, although this embodiment demonstrated the case where the 2nd aperture blade 4 was arrange | positioned in the side close | similar to the base member 1 rather than the some 1st aperture blade 5, the 2nd aperture blade 4 was replaced with several You may arrange | position so that it may be located in the opposite side (partition plate 7 side) from the base member 1 rather than the 1st aperture blade 5. FIG. Thereby, the curvature and the fall to the partition plate 7 side of the 1st aperture blade 5 can be restrict | limited.

  If the warp and the fall of the first diaphragm blade 5 and the second diaphragm blade 4 can be restricted, there is an advantage that the diaphragm accuracy is improved. Furthermore, there is an advantage that the change in the aperture opening area due to the posture difference can be reduced.

  Further, in the present embodiment, the case where the tip portion 4e of the second diaphragm blade 4 is sandwiched and supported by the base member 1 and the partition plate 7 has been described, but the tip of the second diaphragm blade 4 is supported on the base member 1. You may make it support the front-end | tip part 4e of the 2nd aperture blade 4 by another method, such as providing the rail engaged with the part 4e.

  Further, as shown in FIG. 7, the diaphragm device described in the present embodiment has a shutter function for fully closing the diaphragm opening, and the minimum diaphragm state with the smallest diaphragm opening may be a fully closed state. .

(Second Embodiment)
FIG. 8 is an exploded view of an iris diaphragm device as a second embodiment of the light amount adjusting device of the present invention. In 1st Embodiment, the case where the 2nd aperture blade 4 was arrange | positioned so that it might overlap with the base member 1 side and the other side with respect to several 1st aperture blade 5 was demonstrated. In the present embodiment, the third diaphragm blade 12 is disposed between at least one first diaphragm blade 4 and second diaphragm blade 5.

  The third aperture blade 12 does not cross the fixed opening 1a at least in the minimum aperture state, and the tip end portion 12e does not overlap the base member 1 in the optical axis direction. Further, the third diaphragm blade 12 does not have a support portion like the first diaphragm blade 5.

  The second diaphragm blades 4 and the first diaphragm blades 5 can limit the warping and falling of the diaphragm blades. Further, since the third diaphragm blade 12 has a smaller shape area than the first diaphragm blade and the second diaphragm blade, the sliding resistance between the diaphragm blades is small, and it is effective for operation.

(Third embodiment)
FIG. 9 is an exploded view showing an iris diaphragm device as a third embodiment of the light amount adjusting device of the present invention. In the first embodiment, a case has been described in which the second diaphragm blades 4 are arranged so as to overlap the plurality of first diaphragm blades 5 on one of the base member 1 side and the opposite side. In the embodiment, only the second aperture blade 5 is disposed. The support portion 5f of the diaphragm blade 5 can limit the warpage or the fall of the diaphragm blade.

(Fourth embodiment)
FIG. 5 shows an imaging apparatus as an example of an optical apparatus on which the diaphragm device described in the first, second, or third embodiment is mounted. Reference numerals 1, 3, 4, 5, and 6 indicate that the member to which the reference numeral is attached is a member to which the same reference numeral is attached in the first embodiment.

  Light from the subject enters the photographing optical system 15, passes through a diaphragm aperture of a diaphragm device included in the photographing optical system 15, and forms a subject image on the image sensor 13 constituted by a CCD sensor, a CMOS sensor, or the like. . The imaging element 13 photoelectrically converts the subject image and outputs an imaging signal. The imaging device generates a video signal from the imaging signal, and records or displays the video signal.

  In the aperture devices of the first to third embodiments, the warping of the plurality of first aperture blades 5 toward the base member 1 side is limited by the second aperture blades 4. Can be arranged at a position close to the diaphragm blades 4 and 5. Therefore, the photographing optical system 15 and the imaging device can be reduced in size as compared with the case of using a conventional diaphragm device in which the warp of the diaphragm blade 105 has occurred as shown in FIG.

  The diaphragm device described in the first and second embodiments can be mounted not only on the imaging device described in this embodiment but also in other optical devices such as an interchangeable lens.

  Each embodiment described above is only a representative example, and various modifications and changes can be made to each embodiment in carrying out the present invention.

  It is possible to provide a small light amount adjusting device having a favorable aperture opening shape and a small optical device equipped with the same.

DESCRIPTION OF SYMBOLS 1 Base member 3 Drive ring 4 2nd aperture blade 5 1st aperture blade 6 Blade drive part 7 Partition plate 8 ND filter 9 Filter holding plate 11 Case 12 3rd aperture blade 13 Imaging element 14 Lens

Claims (14)

A light passage opening forming member that forms an opening through which light passes; and
A plurality of light quantity adjustment blades rotating into the opening,
The plurality of light quantity adjustment blades include a non-transverse rotation blade whose rotation direction rear end portion overlaps an edge of the opening portion when the rotation direction front end portion of the blade is positioned in the opening portion. Light quantity adjustment device.   2. The light amount adjusting device according to claim 1, wherein all of the plurality of light amount adjusting blades are configured by the non-transverse rotating blades.   2. The light amount adjusting device according to claim 1, wherein the plurality of light amount adjusting blades include a transverse rotating blade that rotates across the opening and overlaps with an edge of the opening. .   The plurality of light quantity adjusting blades are formed by overlapping a second blade group in which a plurality of the transverse rotating blades are overlapped on a first blade group in which the plurality of non-crossing rotating blades are overlapped. The light quantity adjusting device according to claim 3.   5. The light passage opening forming member includes a fixed opening forming member in which a fixed opening through which light passes is formed, or an annular driving member that rotates the plurality of light quantity adjusting blades. The light quantity adjusting device according to any one of the above. A base member having a fixed opening through which light passes;
A plurality of aperture blades that overlap with each other in the optical axis direction, which is the traveling direction of the light, form an aperture aperture that limits the fixed aperture, and rotate relative to the base member to change the aperture aperture. And
The plurality of diaphragm blades are:
At least in the minimum aperture state in which the aperture opening is minimum, the tip of each aperture blade, which is the end opposite to the rotation center side with respect to the base member, overlaps the base member in the optical axis direction. A plurality of first diaphragm blades that overlap the base member at a support portion different from the rotation center side and the tip portion;
At least in the minimum aperture state, a plurality of second aperture blades in which the tip portion of each aperture blade that is the end opposite to the rotation center side with respect to the base member overlaps the base member in the optical axis direction Including
The second diaphragm blade overlaps the first diaphragm blade on at least one of the side close to the base member and the opposite side in the optical axis direction. .   The said front-end | tip part of a said 2nd aperture blade overlaps with the said base member in the said optical axis direction in all the aperture states in which the said aperture opening smaller than the said fixed aperture is formed. Light quantity adjustment device.   The second diaphragm blades press the first diaphragm blades so as to limit warpage of the plurality of first diaphragm blades in the optical axis direction at least in the minimum diaphragm state. Item 7. The light amount adjusting device according to Item 6.   9. The light amount adjusting device according to claim 6, further comprising a cover member that sandwiches the tip portion of the second diaphragm blade with the base member.   The light quantity adjusting device according to any one of claims 6 to 9, wherein the minimum aperture state in which the aperture opening is minimum is a fully closed state. A base member having a fixed opening through which light passes;
A plurality of aperture blades that overlap with each other in the optical axis direction, which is the traveling direction of the light, form an aperture aperture that limits the fixed aperture, and rotate relative to the base member to change the aperture aperture. And
Each of the plurality of aperture blades has a rotation direction tip that is an end opposite to the rotation center side with respect to the base member, and does not overlap the base member in the optical axis direction. A light amount adjusting device, characterized in that the light amount adjusting device is a non-transverse rotating blade that overlaps the base member at a support portion different from the rotation center side and the tip portion on the rear end side. A base member having a fixed opening through which light passes;
A plurality of aperture blades that overlap with each other in the optical axis direction, which is the traveling direction of the light, form an aperture aperture that limits the fixed aperture, and rotate relative to the base member to change the aperture aperture. And
The plurality of diaphragm blades are:
At least in the minimum aperture state in which the aperture opening is minimum, the tip of each aperture blade, which is the end opposite to the rotation center side with respect to the base member, overlaps the base member in the optical axis direction. The at least one first diaphragm blade that overlaps the base member at a support portion different from the rotation center side and the tip portion,
At least in the minimum aperture state, at least one second end portion of each aperture blade, which is the end opposite to the rotation center side of the base member, overlaps the base member in the optical axis direction. Aperture blades,
At least in the minimum aperture state in which the aperture opening is minimum, the tip of each aperture blade, which is the end opposite to the rotation center side with respect to the base member, overlaps the base member in the optical axis direction. And a light amount adjusting device including at least one third diaphragm blade not having a support part separate from the rotation center side and the tip part.   An optical apparatus comprising an optical system including the light amount adjusting device according to any one of claims 1 to 12.   An imaging apparatus comprising the light amount adjusting device according to claim 1.

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