JP2018141829A - Exposure amount adjustment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure amount control device which has achieved downsizing.SOLUTION: An exposure amount adjustment device comprises: a plurality of blade members 63 for forming a variable opening 63h; a blade drive rotating plate 62 having a rotation-regulated protrusion 62c, and driving a plurality of the blade members so as to be tunable; a base 61 having a rotation range regulation recess 61d for regulating a rotation range of the blade drive rotating plate; and a blade pressing member 64 having a rotation regulation protrusion 64a formed, which extends in parallel with a center axis O of the variable opening, enters one end part within the rotation range regulation recess in a circumferential direction, and prevents a diameter of the variable opening from becoming excessively small when the rotation-regulated protrusion abuts thereon, and regulates the rotation range of the blade drive rotating plate within a range from an open diameter to a minimum diameter of the variable opening. When the rotation-regulated protrusion is arranged at one end part in the circumferential direction, the rotation range regulation recess sets the variable opening to the excessive small diameter, and when the rotation-regulated protrusion is arranged at the other end part in the circumferential direction, sets the variable opening to the open diameter. When the variable opening becomes the open diameter, one of a plurality of the blade members is arranged so as to cover one end part of the rotation range regulation recess in the circumferential direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an exposure adjustment device such as a diaphragm provided in an imaging device or a lens barrel.

  2. Description of the Related Art Conventionally, an imaging apparatus such as a digital camera that acquires an optical image formed by an imaging optical system as an image signal using an imaging element or the like has been generally put into practical use and widely used. In general, this type of imaging apparatus includes a lens barrel having an imaging optical system for forming an optical image of a subject.

  In a conventional lens barrel, for example, an imaging optical system configured by combining a plurality of optical lenses to form an optical image of a subject, and a part of the optical lens group of the imaging optical system advance and retreat in a direction along the optical axis. In general, the lens driving mechanism is configured to include a moving lens driving mechanism and an exposure amount adjusting device such as a diaphragm device or a shutter device that adjusts the amount of light transmitted through the imaging optical system. In addition to the form provided in the lens barrel, the exposure amount adjusting apparatus may be provided on the imaging apparatus side.

  In this type of exposure adjustment apparatus, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2012-208388, an opening through which a light beam from a subject (hereinafter referred to as subject light) passes is provided. In general, a plurality of diaphragm blades, a driving mechanism for driving the plurality of diaphragm blades, and the like are provided in the region on the side.

  Then, the conventional exposure amount adjusting device appropriately drives each of the plurality of diaphragm blades in a region on the outer peripheral side of the opening through which the subject light passes, and displaces the opening area, thereby shifting the subject light passing through the opening. The amount of light can be adjusted.

JP 2012-208388 A

  However, in the conventional exposure amount adjusting apparatus disclosed by the above-mentioned Japanese Patent Application Laid-Open No. 2012-208388 and the like, various kinds of elements such as an aperture blade and its driving mechanism are used so as not to block subject light passing through the aperture. The component must be disposed in the region on the outer peripheral side of the opening. The conventional exposure amount adjusting device having such a configuration has a problem that the size is increased in the outer peripheral side of the opening, that is, in the radial direction.

  However, there is always a demand for downsizing of an imaging device carried by a user (user) and a lens barrel applied thereto. Therefore, downsizing of the exposure adjustment device disposed inside the imaging device or the lens barrel is a problem that is always strongly desired.

  The present invention has been made in view of the above-described points, and an object of the present invention is to reduce the size particularly in the radial direction while maintaining a basic configuration in an exposure adjustment device such as an aperture device. It is to provide an realized exposure control apparatus.

  In order to achieve the above object, an exposure amount control apparatus according to an aspect of the present invention includes a plurality of variable apertures that each rotate to displace an area in order to adjust a passing light amount. A blade member, a first opening, and a rotation-regulated convex portion that rotates in a circumferential direction around the first opening and extends in the outer diameter direction. Each of the plurality of blade members is rotated by a blade driving rotary plate that rotates the plurality of blade members from the open diameter to the excessively small diameter exceeding the desired minimum diameter through the desired minimum diameter. A second opening disposed around the second opening, and a rotation range restricting recess that extends in a concave shape in a circumferential direction around the second opening and restricts the rotation range of the blade drive rotating plate. A plurality of blade members and the drive rotation And an annular portion that is sandwiched between the base and the base in a movable state, and extends in a direction parallel to the central axis of the variable opening and enters the one circumferential end in the rotation range restricting concave portion. When the rotation-regulated convex portion comes into contact, the variable opening is prevented from becoming the excessively small diameter, and the variable opening restricts the rotation range of the drive rotating plate in the range from the open diameter to the desired minimum diameter. A blade pressing member formed with a rotation restricting convex portion, and the rotation range restricting concave portion has the variable opening as the excessively small diameter when the rotation restricted convex portion is disposed at one circumferential end. When the rotation restricted convex portion is disposed at the other circumferential end, the variable opening is set to the opening diameter, and when the variable opening reaches the opening diameter, at least one of the plurality of blade members is rotated at least Circumferential direction of range control recess It is arranged so as to cover the end portion.

  According to the present invention, it is possible to provide an exposure amount control device that achieves downsizing particularly in the radial direction while maintaining a basic configuration in an exposure amount adjustment device such as a diaphragm device.

1 is an exploded perspective view of a main part of a lens barrel to which an exposure adjustment apparatus according to an embodiment of the present invention is applied. 1 is an enlarged longitudinal sectional view of the lens barrel of FIG. 1 cut along a plane including the optical axis. 1 is an external perspective view showing only an aperture unit that is an exposure adjustment device (aperture device) according to an embodiment of the present invention. FIG. 3 is an exploded perspective view showing an exploded aperture unit which is the exposure amount adjusting device (aperture device) of FIG. 3. FIG. 3 is an exploded perspective view showing the main components of the aperture unit that is the exposure adjustment device (aperture device) in FIG. 3. The top view at the time of seeing the state after the assembly completion of the aperture unit which is the exposure amount adjusting device (aperture device) of FIG. 3 from the rear side The principal part expanded sectional view which shows the cross section which follows the arrow [7]-[7] line of FIG. The top view which looked at the state which assembled | attached the blade drive rotary plate to the base from the rear surface R side in the aperture unit which is the exposure amount adjusting device (aperture device) of FIG. The main part enlarged view which shows the state which expanded the part shown by code | symbol [9] of FIG. 8, and also assembled the aperture blade. The top view which looked at the aperture unit of the state which rotated the blade | wing drive rotation board only the predetermined amount from the state of FIG. 8 from the rear surface R side. Fig. 10 is an enlarged view of the main part showing a state where the portion indicated by reference numeral [11] in Fig. 10 is enlarged and the diaphragm blades are further assembled. The top view which looked at the aperture | diaphragm | squeeze unit of the state which assembled | attached the blade | wing | wooden blade member on the base in the state of FIG. The principal part expanded sectional view which shows the cross section along arrow [13]-[13] of FIG. 10 is a diagram showing a state where the blade driving rotary plate is further rotated by a predetermined amount from the states of FIGS. 10 and 12 to be in a “desired minimum diameter” state. FIG. 14 is a diagram showing a state where the blade drive rotating plate is further rotated by a predetermined amount in a predetermined direction from the state of FIG. The top view which looked at the aperture | diaphragm | squeeze unit of the state which assembled | attached the blade | wing feather member in the state of FIG. 15 and the assembly was completed from the rear surface R side. Incidentally, in various parts of the drawings, the diaphragm blades are expressed as transparent for convenience of drawing, but in reality, each diaphragm blade is made of a light non-transmitting material, and this is not the case.

  The present invention will be described below with reference to the illustrated embodiments. Each drawing used in the following description is schematically shown. In order to show each component in a size that can be recognized on the drawing, the dimensional relationship and scale of each member are different for each component. May be shown. Therefore, the present invention is only in the illustrated form with respect to the quantity of each component described in each drawing, the shape of each component, the ratio of the size of each component, the relative positional relationship of each component, and the like. It is not limited.

[One Embodiment]
1 and 2 are views showing a lens barrel to which an exposure adjustment apparatus according to an embodiment of the present invention is applied. Among these, FIG. 1 is an exploded perspective view of a main part of the lens barrel. FIG. 2 is an enlarged longitudinal sectional view of the lens barrel cut along a plane including the optical axis.

  First, before describing the detailed configuration of an aperture stop device that is an exposure amount adjustment device of the present embodiment, the overall configuration of a lens barrel to which the exposure amount adjustment device (aperture device) is applied will be briefly described below.

  In one embodiment of the present invention, for example, an optical image formed by a plurality of optical lenses is photoelectrically converted using a solid-state imaging device, and an image signal obtained thereby is converted into digital image data representing a still image or a moving image. The digital data generated in this manner is recorded on a storage medium, and applied to an imaging apparatus configured to be able to reproduce and display a still image or a moving image on a display device based on the digital image data recorded on the storage medium. This is an example of a lens barrel to be used.

  In addition, an embodiment of the present invention exemplifies a lens barrel that is applied to a so-called interchangeable lens camera in which a lens barrel is detachably attached to an imaging apparatus main body. The present invention is not limited to this type of lens barrel, and can be similarly applied to, for example, a so-called lens-integrated camera in which an imaging apparatus main body and a lens barrel are integrally formed.

  In the present embodiment, the optical axis of the imaging optical system in the lens barrel is represented by the symbol O. In the direction along the optical axis O of the lens barrel, a surface facing the subject is referred to as a front surface, and a surface having the mount portion is referred to as a rear surface.

  The configuration of the lens barrel itself to which the exposure amount adjusting device (aperture device) of the present embodiment is applied basically has the same configuration as that of a lens barrel that has been practically used in the past. Therefore, detailed description of members having the same configuration as that of a conventional lens barrel will be omitted and will be briefly described below.

  As shown in FIGS. 1 and 2, a lens barrel 1 to which an aperture unit 19 that is an exposure amount adjusting device and an aperture device of the present embodiment is applied, includes a front decorative ring 11, a hood mounting ring 12, and a front side. Exterior ring 13, first group lens frame A14, first group lens frame B15, front unit group including first lens group 31 and the like, exterior rear cylinder 16, and lens substrate 29 (not shown in FIG. 1; see FIG. 2) ), Lens side mount portion 17, contact holding ring 18, aperture unit 19, elastic unit oscillator 20 as an elastic member (see FIG. 1; not shown in FIG. 2), focus ring 21, and second lens group. Frame 22, third group lens frame 23, fourth group lens frame 24 (not shown in FIG. 1; see FIG. 2), internal fixed cylinder 25 (see FIG. 1; see FIG. 2), second lens group 32, third lens group 33, the fourth lens group 34 (FIG. 1 not shown) ; It is mainly constituted by the side unit group or the like after including the see FIG. 2) or the like.

  The front decoration ring 11 is fixed to the front surface of the hood mounting ring 12 using a joining member such as a double-sided tape 26 (see FIG. 1). Further, the hood mounting ring 12 is fixed by screws using a plurality of screws 27a (see FIG. 1) on the front surface side of the internal fixed cylinder 25 with the front exterior ring 13 interposed therebetween.

  The first group lens frame A <b> 14 and the first group lens frame B <b> 15 are holding frame members that hold a first lens group 31 that includes a plurality of optical lenses and is disposed near the front surface of the lens barrel 1. The first group lens frame A14 is screwed and fixed to the fixing portion of the inner wall surface of the inner fixing cylinder 25 using a plurality of screws 27b (see FIG. 1). Similarly, the first group lens frame B15 is fixed to the fixing portion of the inner wall surface of the internal fixing cylinder 25 using a plurality of screws 27c (see FIG. 1).

  The constituent units constituting the front unit group can be taken out to the front side of the lens barrel 1. In other words, when assembling the lens barrel 1, these constituent units constituting the front unit group are sequentially inserted from the front side of the lens barrel 1 in a predetermined order and assembled at predetermined portions. It has a form like this.

  The internal fixed cylinder 25 is a cylindrical member in which the focus ring 21 is rotatably disposed on the outer surface. Inside the internal fixed cylinder 25, there are a digital unit oscillator 20 (see FIG. 1; FIG. 2 not shown), a diaphragm unit 19, a second group lens frame 22, a third group lens frame 23, and a fourth group lens frame 24 ( A second lens group 32, a third lens group 33, a fourth lens group 34 (not shown in FIG. 1; see FIG. 2), etc., which are held by each frame member of FIG. Yes. An annular exterior rear cylinder 16 is provided on the rear outer periphery of the fixed and fixed cylinder 25 in the optical axis direction. A lens substrate 29, a lens side mount portion 17, a contact holding ring 18 and the like are fixedly provided on the rear surface of the exterior rear cylinder 16.

  The lens side mount portion 17 is fixed to the fixing portion on the rear surface of the internal fixing cylinder 25 with screws using a plurality of screws 27e (see FIG. 1). Further, the contact holding ring 18 is fixed to the fixing portion on the rear surface of the internal fixing cylinder 25 with screws using a plurality of screws 27f (see FIG. 1).

  The second group lens frame 22 is a holding frame member that fixes and holds the second lens group 32 including a plurality of optical lenses. Similarly, the third group lens frame 23 is a holding frame member that fixes and holds the third lens group 33 including a plurality of optical lenses. The fourth group lens frame 24 is a holding frame member that fixes and holds the fourth lens group 34 formed of an optical lens.

  The third group lens frame 23 is configured to be capable of moving back and forth in a direction along the optical axis O by a driving source and a driving mechanism (not shown). That is, the third lens group 33 is a movable lens group for performing a focusing operation, for example.

  The diaphragm unit 19 is an exposure adjustment device that adjusts the amount of light that passes through the imaging optical system, and is a diaphragm device that includes a single unit.

  For this purpose, the diaphragm unit 19 is a structural unit having a substantially circular opening 19h as a whole and having a substantially annular shape as shown in FIG. The diaphragm unit 19 is disposed so that the central axis of the circular aperture substantially coincides with the optical axis O of the imaging optical system.

  The lens barrel 1 to which the aperture unit 19 that is the exposure amount adjustment device (aperture device) of the present embodiment is applied is schematically configured as described above. In addition, about the structure which abbreviate | omitted description, it shall have the structure substantially the same as the lens-barrel generally put to practical use conventionally.

  Next, a detailed configuration of the aperture unit 19 which is an exposure adjustment device (aperture device) of the present embodiment will be described below with reference to FIGS.

  3 to 7 are diagrams showing a detailed configuration of the aperture unit 19 which is the exposure amount adjusting device (aperture device) of the present embodiment. FIGS. 8 to 16 are views showing the operation of the aperture unit 19 which is an exposure adjustment device (aperture device) of the present embodiment.

  Among these, FIG. 3 is an external perspective view showing only the aperture unit 19 which is the exposure amount adjusting device (aperture device) of the present embodiment from the lens barrel 1. FIG. 4 is an exploded perspective view showing the aperture unit 19 which is an exposure adjustment device (aperture device) of the present embodiment in an exploded manner. FIG. 5 is an exploded perspective view showing the main components of the main components of the aperture unit 19 that is the exposure adjustment device (aperture device) of the present embodiment.

  3 to 5, the side indicated by the arrow symbol F is referred to as the front surface, and similarly, the side indicated by the arrow symbol R is referred to as the rear surface. Here, the front surface F of the aperture unit 19 is a surface facing a subject (not shown) when the aperture unit 19 is incorporated in the lens barrel 1 to which the aperture unit 19 is applied. Further, in FIG. 5, illustrations of fine parts to be attached to the aperture unit 19, such as an aperture drive motor, electric parts (see FIG. 4), screws, and the like are omitted.

  FIG. 6 is a plan view of the state after completion of the assembly of the aperture unit 19 that is the exposure amount adjustment device (aperture device) of the present embodiment, as viewed from the rear side. FIG. 7 is an enlarged cross-sectional view of a main part showing a cross section taken along line [7]-[7] in FIG. Specifically, FIG. 7 mainly shows a configuration in the vicinity of the rotation restricting convex portion 64a.

  As shown in FIGS. 3 to 5 and the like, the diaphragm unit 19 includes an electrical circuit such as a base 61, a blade drive rotating plate 62, a plurality of blade members 63, a blade spring member 64, and a diaphragm drive motor 28. It is comprised by the component and the flexible printed circuit board 30 grade | etc.,.

  In the diaphragm unit 19, the blade drive rotating plate 62 and the plurality of blade members 63 can perform predetermined rotation and rotation inside a casing formed by the base 61 and the blade spring member 64, respectively. It is arranged in a state (movable state). Further, on the outer peripheral side of the base 61, electrical components such as the diaphragm drive motor 28 and the like, the flexible printed circuit board 30 and the like are disposed.

  Here, the aperture drive motor 28 is a drive source for rotating the plurality of blade members 63, respectively. The diaphragm drive motor 28 is fixed to a predetermined position on the front surface F of the diaphragm unit 19 using, for example, a plurality of screws 27h (see FIGS. 3 and 4).

  From the diaphragm unit 19, a flexible printed circuit board 30 that electrically connects the electrical components of the diaphragm unit 19 and the imaging apparatus main body (not shown) extends. A diaphragm drive motor 28 and the like are connected to the flexible printed circuit board 30 and a position detection sensor (PI) that detects the positions of various electrical components, for example, a plurality of blade members 63 driven by the diaphragm drive motor 28. A photo interrupter and the like (not shown) are mounted.

  The flexible printed circuit board 30 extends from the aperture unit 19 toward the rear of the lens barrel 1, and the tip of the flexible printed circuit board 30 is connected to a connector 29a (see FIG. 2) mounted on the lens board 29. Has been.

  A plurality of electrical contacts (not shown) provided on the contact holding ring 18 are connected to the lens substrate 29. An electrical contact (not shown) of the contact holding ring 18 is connected to the imaging barrel (not shown) when the lens barrel 1 is connected to the imaging device (not shown) via a mutual mount. ) To establish an electrical connection between the lens barrel 1 and the imaging device (not shown).

  Therefore, the flexible printed circuit board 30 extended from the aperture unit 19 receives an output signal (such as a drive control signal for driving the aperture drive motor 28) or drive power from the image pickup apparatus side, and the aperture unit 19 side. Is used to transmit an output signal from a position detection sensor (not shown) or the like to the imaging device (not shown) side.

  After the diaphragm unit 19 is inserted into the inner fixed cylinder 25 from the front to the rear in the optical axis direction, a predetermined part on the rear surface side is at the substantially center of the inner fixed cylinder 25 in the optical axis direction. In other words, it is arranged in a state of being in contact with and positioned at a contact portion 25a (see FIG. 2) having a surface orthogonal to the optical axis.

  The plurality of blade members 63 in the diaphragm unit 19 are each provided with a rotation hole 63a serving as a rotation center and a pin 63b for receiving a rotation drive. In order to adjust the amount of light that passes through the imaging optical system, each member is a member that forms a variable opening 63h through which the photographic light beam passes by rotating to displace the area. In addition, about the structure of blade member 63 itself, what consists of a structure substantially the same as the diaphragm blade in the aperture device generally utilized conventionally is applied, and the detailed description is abbreviate | omitted.

  The blade driving rotary plate 62 is a component member for rotating and driving each of the plurality of blade members 63. The blade driving rotary plate 62 is formed in a substantially annular shape having a substantially circular opening 62h (first opening) at the center. Further, the blade drive rotating plate 62 is disposed so as to be able to rotate forward and backward with respect to the base 61 in the circumferential direction around the opening 62h.

  In the present specification, before and after this, the rotation of the blade drive rotating plate 62 is expressed as “rotation”, and the rotation of the blade member 63 is expressed as “rotation”. The “rotation” and “rotation” are not substantially different from each other in meaning, and are intentionally performed in the present specification and claims for the purpose of easy understanding and determination of the action of members. In addition, in some documents, there is a description that “rotation” is used when rotating in only one direction, and “rotation” is used when rotating in both directions. Excludes such implications. In the present specification and claims, both “rotation” and “rotation” are defined as words having a meaning of rotating in both directions.

  For this purpose, the blade drive rotating plate 62 prevents a separation of the base 61 in the optical axis O direction while ensuring rotation within a predetermined range in the rotational direction with respect to the base 61 (3 in this example). ) Bayonet locking claws 62a (see FIGS. 4, 5 and 8), locking arm portions 62b (see FIGS. 4 and 5) for locking the other end of a coil spring 65 described later, and the outer diameter direction And a rotation restricted convex portion 62c formed so as to extend in the direction.

Further, the blade drive rotating plate 62 is provided with a sector gear 62d (see FIGS. 3 and 5) that receives the rotational driving force from the aperture driving motor 28 on the front surface F side. A pinion gear 28a (see FIG. 4) fixed to the drive shaft of the diaphragm drive motor 28 is screwed into the sector gear 62d. Thereby, the rotational driving force of the aperture driving motor 28 is transmitted to the blade driving rotary plate 62. The diaphragm driving motor 28 is rotationally driven by an imaging device (not shown), for example, by a control unit of the imaging device, so that the blade driving rotary plate 62 rotates around the optical axis O. Cam blades for rotationally driving the plurality of blade members 63 are arranged on the blade drive rotating plate 62 so as to surround the opening 62 h and are spaced apart from each other in the circumferential direction. Each cam is provided on the blade member 63. When the pin 63b is fitted and the blade drive rotating plate 62 is rotated, these cam grooves rotate each of the plurality of blade members 63 around a blade support shaft 61g described later.
Therefore, this realizes rotational drive control of the plurality of blade members 63.

  In this way, in the aperture unit 19 of the present embodiment, by rotating the plurality of blade members (63), the variable opening 63h is changed from the “open diameter” state to the “desired minimum diameter” state. It is configured to be able to be displaced between the “desired minimum diameter” state and the “excessive and small diameter” state.

  The states of the variable opening 63h are as follows. That is, the “open diameter” state refers to a state in which the variable opening 63 h formed by the plurality of blade members 63 is most opened (opened). Further, the “desired minimum diameter” state is a state in which the variable aperture 63h formed by the plurality of blade members 63 is set to have the smallest aperture diameter (minimum aperture state). The “excessive and small diameter” state is a state where the state is further reduced from the “desired minimum diameter” state. In the aperture unit 19, exposure adjustment is performed by displacing the variable opening 63 h between the “open diameter” state and the “desired minimum diameter” state. In this case, an arbitrary position between the “open diameter” state and the “desired minimum diameter” state, that is, an intermediate position is referred to as an “intermediate aperture” state.

  The base 61 is a member constituting the main part of the aperture unit 19. The base 61 has a ring-shaped portion 61a having a substantially circular opening 61h (second opening) in the center, and an optical axis formed so as to surround the outer periphery of the ring-shaped portion 61a. The peripheral wall portion 61b is extended (see FIGS. 3 to 5).

  Around the opening 61h of the base 61, on the front surface F side (see FIGS. 3 and 5), a coil spring 65 and the like are disposed in addition to the diaphragm drive motor 28 and the flexible printed circuit board 30. In addition, on the rear surface R side (see FIG. 4) around the opening 61h of the base 61, each of the plurality of blade members 63 is rotatably arranged (see FIG. 4).

  Here, one end of the coil spring 65 is locked to a fixing portion 61 c (see FIG. 3) of the base 61, and the other end is locked to a locking arm portion 62 b extending from the blade drive rotating plate 62. Accordingly, the coil spring 65 urges the blade driving rotary plate 62 in a predetermined one rotation direction with respect to the base 61 (fixed portion). As described above, the blade drive rotating plate 62 is a member that drives the plurality of blade members 63 by rotating in the forward and reverse directions around the opening 62h. Therefore, when the blade drive rotating plate 62 is always urged in one direction by the coil spring 65, the plurality of blade members 63 are configured to maintain the minimum diameter of the variable opening 63h.

  Further, the base 61 extends in a concave shape in the circumferential direction centering on the opening 61h and in the direction parallel to the optical axis in the surface on the rear surface R side (see FIG. 4) around the opening 61h. A rotation range restricting recess 61 d that restricts the rotation range of the rotating plate 62 is provided. Further, at one end in the circumferential direction of the rotation range restricting recess 61d, a rotation restricting convex portion 64a, which will be described later of the blade spring member 64, extends further radially from the rotation range restricting recess 61d. An opening 61e is formed to enter in a direction parallel to (see FIGS. 4 and 8).

  Furthermore, the base 61 is located in a position on the rear surface R side (see FIG. 4) around the opening 61h so as not to interfere with the position where the opening 61e is disposed. During the assembly process, a plurality of bayonet openings 61f are formed for the bayonet locking claws 62a of the blade drive rotating plate 62 to enter and be arranged in a direction parallel to the optical axis O (reference numeral in FIG. 8). (Refer site | part (three places) shown by [B1]). In the circumferential direction following the plurality of bayonet openings 61f, the bayonet locking claw 62a is formed in substantially the same form as the rotation range restricting recess 61d, and allows the bayonet locking claws 62a to rotate around the optical axis O. The bayonet groove | channel (not shown) which prevents the movement of is provided.

  Here, in the aperture unit 19 of the present embodiment, when the rotation restricted convex portion 62c is disposed at one circumferential end of the rotation range restricting concave portion 61d, the variable opening 63h formed by the blade member 63 is , The “oversized and small diameter” state is further narrowed down than the “desired minimum diameter” state.

  Similarly, when the rotation restricted convex portion 62c is disposed at the other circumferential end of the rotation range restricting concave portion 61d, the variable opening 63h formed by the blade member 63 is in an “open diameter” state. It is comprised so that it may become.

  A plurality of blade support shafts 61g are arranged at substantially equal intervals in the circumferential direction in the vicinity of the outer peripheral edge in the surface on the rear surface R side (see FIG. 4) of the base 61 (FIG. 4). Etc.). The plurality of blade support shafts 61g are provided in the same number as the plurality of blade members 63. The plurality of blade members 63 are disposed so as to rotate around the blade support shaft 61g.

  Thus, in the aperture unit 19 of the present embodiment, the rotation restricted convex portion 62c of the blade driving rotary plate 62 is between the circumferential end portion and the other circumferential end portion of the rotation range restricting recess portion 61d. By moving, the area of the variable opening 63h by the blade member 63 is displaced. In this case, the rotation range of the blade drive rotary plate 62 is restricted at a position where the rotation restricted convex portion 62c of the blade drive rotary plate 62 contacts either end of the rotation range restriction concave portion 61d. It is configured as follows.

  The blade pressing member 64 is formed to have a substantially annular shaped annular portion 64b having an opening 64h (third opening) at the center. The annular portion 64b is fixed to a predetermined position on the outer peripheral edge of the base 61 by a plurality of screws 27g. At this time, the plurality of blade members 63 and the blade driving rotary plate 62 are held in a movable state between the annular portion 64b of the blade pressing member 64 and the base 61, respectively.

  Further, the annular portion 64b of the blade pressing member 64 is restricted in rotation so as to extend in a direction parallel to the central axis (optical axis O) of the variable opening 63h (opening 61h, opening 62h, opening 64h, opening 19h). A convex portion 64a is formed. The rotation restricting convex portion 64a is directed to the central axis (optical axis O) in the radial direction of the annular portion 64b of the blade pressing member 64 from the long arm portion extending in the direction parallel to the optical axis O and the tip of the long arm portion. It is formed in the substantially L shape which has the short arm part extended in this way (refer FIG. 5, FIG. 7).

  The rotation restricting convex portion 64a is formed at one end in the circumferential direction of the rotation range restricting concave portion 61d of the base 61 when the blade pressing member 64 is attached and fixed to the base 61 at a regular position. It is arranged to enter the opening 61e from the optical axis O direction. In this state (that is, in a state where the aperture unit 19 is assembled), the rotation restricting convex portion 64a has the rotation restricted convex portion 62c abutting against the circumferential side surface 61d1 at one circumferential end of the rotation range restricting concave portion 61d. Preventing contact.

  In other words, the rotation restricting convex portion 64a is arranged such that when the blade pressing member 64 is attached and fixed at a proper position with respect to the base 61 and the diaphragm unit 19 is assembled, the rotation restricting convex portion 64a It arrange | positions at the opening part 61e of the circumferential direction one end part.

  In this state, when the blade drive rotating plate 62 rotates toward the one end in the circumferential direction of the rotation range restricting recess 61d in the circumferential direction centering on the opening 62h, the rotation restricted projecting portion 62c becomes the rotation range restricting recess. Before contacting the circumferential side surface 61d1 at one circumferential end of 61d, it is configured to contact the rotation restricting convex portion 64a.

  Therefore, the rotation restricting convex portion 64a prevents the rotation restricted convex portion 62c from coming into contact with the circumferential side surface 61d1 at one end portion in the circumferential direction when the diaphragm unit 19 is assembled. This prevents the variable opening 63h from becoming “excessive and small diameter”. As a result, the rotation restricting convex portion 64a restricts the rotation range of the blade drive rotating plate 62 in the range from the opening diameter to the desired minimum diameter of the variable opening 63h.

  As shown in FIG. 6, the blade pressing member 64 is a portion in the vicinity where the rotation restricting convex portion 64 a is formed, and faces the opening 61 e at one end in the circumferential direction of the rotation range restricting concave portion 61 d. A window 64c is formed at the site.

  Therefore, in a state where the aperture unit 19 is assembled, when the variable opening 63h formed by the plurality of blade members 63 has an “open diameter”, at least one of the plurality of blade members 63 is at least the rotation range restricting recess 61d. Is arranged so as to cover one end portion in the circumferential direction, that is, the window portion 64c (see FIG. 6).

  The configuration of the aperture unit 19 of the present embodiment is as described above. Parts that are not described in detail in the above description are assumed to have substantially the same configuration as that of a conventionally general diaphragm device.

  Next, the operation of the aperture unit 19 of the present embodiment will be described below mainly using FIGS.

  First, the state when the aperture unit 19 of the present embodiment is in the assembled state is as shown in FIGS. In the aperture unit 19 in this state, the variable opening 63h formed by the plurality of blade members 63 is in an “open diameter” state as shown in FIG. At this time, the window 64c of the blade pressing member 64, that is, the opening 61e at one end in the circumferential direction of the rotation range restricting recess 61d is covered with one of the plurality of blade members 63.

  Further, in the aperture unit 19 at this time, the rotation restricting convex portion 64a of the blade pressing member 64 is disposed in the opening 61e at one end in the circumferential direction of the rotation range restricting concave portion 61d, as shown in FIG. Although not shown, the rotation restricted convex portion 62c of the blade driving rotary plate 62 is in contact with the rotation restricting convex portion 64a in the rotation direction. Thereby, the rotation of the blade drive rotating plate 62 is restricted, and at the same time, the “open diameter” state of the variable opening 63 h of the blade member 63 is maintained.

  The procedure for assembling the aperture unit 19 of this embodiment is roughly as follows. First, FIG. 8 is a plan view of a state in which the blade drive rotating plate 62 is assembled to the base 61 from the rear surface R side in the diaphragm unit 19. FIG. 9 is an enlarged view of the main part showing a state in which the portion indicated by the reference numeral [9] in FIG. 8 is enlarged and the diaphragm blades are further assembled. In addition, in FIG. 9, the state which assembled | attached the blade member 63 with respect to the state of FIG. 8 is shown.

  In the diaphragm unit 19 of the present embodiment, in order to assemble the blade drive rotating plate 62 to the base 61 to obtain the state of FIG. 8, first, the blade drive rotating plate 62 is moved along the optical axis O with respect to the base 61. Approach from direction (parallel direction). At this time, each of the plurality of bayonet locking claws 62 a of the blade drive rotating plate 62 is arranged in correspondence with each of the plurality of bayonet openings 61 f of the base 61. At the same time, the rotation restricted convex portion 62c of the blade driving rotary plate 62 is disposed in the opening 61e at one end in the circumferential direction of the rotation range restricting concave portion 61d of the base 61. Then, the rotation restricted convex portion 62c is brought into contact with one end portion in the circumferential direction of the rotation range regulating concave portion 61d (see FIG. 8).

  After the state shown in FIG. 8 is obtained in this way, one end of the coil spring 65 is locked to the fixing portion 61c (see FIG. 3) of the base 61, and the other end is fixed to the locking arm portion 62b extending from the blade driving rotary plate 62. The blade member 63 to be locked is tensioned (equipped with a pulling force) in the direction in which the blade member 63 to be equipped is closed in the direction to be closed. That is, it is provided between the base 61 and the blade drive rotating plate 62 with a preliminary tension. Thereafter, each of the plurality of blade members 63 is further arranged to be pivotally supported by a predetermined position of the base 61, that is, the blade support shaft 61g. At this time, the plurality of blade members 63 are arranged such that the variable opening 63h is in an “oversized / small diameter” state (see FIG. 9). The blade member 63 at this time is disposed at a position retracted from one end in the circumferential direction of the rotation range restricting recess 61d. Note that the blade member 63 is not shown in FIG. In FIG. 9, only one blade member 63 is displayed for convenience of explanation.

  Here, a reference BL line indicated by a two-dot chain line in FIG. 8 is shown as an assembly reference position of the blade drive rotating plate 62. At this time, as shown in FIGS. 8 and 9, the rotation restricted convex portion 62c of the blade driving rotary plate 62 is at a position corresponding to the opening 61e of the rotation range restricting concave portion 61d of the base 61 as described above. And is in contact with the side surface 61d1 at one end in the circumferential direction of the rotation range regulating recess 61d. In this state, the variable opening 63h formed by the blade member 63 has an “oversized / smallest diameter” exceeding the “desired minimum diameter” (slightly further narrowed than the diaphragm opening 63h shown in FIG. 12). ing.). In this state, the blade member 63 is disposed at a position retracted from one circumferential end of the rotation range restricting recess 61d (see FIG. 9).

  At this time, a plurality (three) of bayonet locking claws 62 a of the blade drive rotating plate 62 are arranged at positions corresponding to the bayonet openings 61 f of the base 61. Therefore, in this state, the blade drive rotating plate 62 can be attached to and detached from the base 61 (see the portion indicated by the reference numeral [B1] in FIG. 8).

  Next, from the state shown in FIGS. 8 and 9, the blade drive rotating plate 62 is rotated by a predetermined amount in the direction of the arrow R1 in FIG. Then, the state shown in FIG. 10 is obtained. Here, for convenience of explanation, the blade member 63 is not shown in FIG.

  FIG. 10 is a plan view of the aperture unit 19 in a state in which the blade driving rotary plate 62 is rotated in a predetermined direction by a predetermined amount from the state of FIG. 8 as viewed from the rear surface R side. In addition, in FIG. 10, as with FIG. 8, the blade member 63 and the blade spring member 64 are not assembled yet. FIG. 11 is an enlarged view of the main part showing a state in which the portion indicated by the reference numeral [11] in FIG. 10 is enlarged and the diaphragm blades are further assembled.

  In this case, a predetermined amount of rotation of the blade drive rotating plate 62 in the direction of the arrow R1 in FIG. 8 is indicated by a two-dot chain line code BL (reference position) and the same code BL1 in FIG. That is, the rotation amount [D1] when the blade driving rotary plate 62 moves from the reference position of the two-dot chain line BL in FIG. 10 to the position of the two-dot chain line BL1 in FIG.

  When the state shown in FIG. 10 is reached, the rotationally regulated convex part 62c of the blade drive rotary plate 62 moves to a position away from one circumferential end of the rotational range regulating concave part 61d, and the opening 61e is opened. Become.

  Moreover, the bayonet latching claw 62a of the blade drive rotating plate 62 is disposed at a position rotated in the circumferential direction from the bayonet opening 61f (see reference numeral [B2] in FIG. 10). Therefore, in this state, the bayonet locking claw 62a is locked by the fixed portion of the base 61, so that the blade drive rotating plate 62 can rotate in the circumferential direction and move in the optical axis O direction. It will not be possible. Accordingly, the blade drive rotating plate 62 is thereby prevented from falling off the base 61 and falling off.

  In the state of FIG. 10, the plurality of blade members 63 have the variable opening 63h in a “desired minimum diameter” state (see FIG. 11). Then, the blade member 63 at this time is arranged at a position retracted from one end in the circumferential direction of the rotation range restricting recess 61d, as in the state of FIG.

  Next, in the state shown in FIGS. 10 and 11, when the blade pressing member 64 is fixed to the base 61 with the screws 27g, the state shown in FIG. 12 is obtained.

  FIG. 12 is a plan view of the aperture unit 19 in a state in which the blade pressing member 64 is assembled to the base 61 in the state of FIG. 11 as viewed from the rear surface R side. FIG. 13 is an enlarged cross-sectional view of a main part showing a cross section taken along arrows [13]-[13] in FIG. FIG. 13 mainly shows a state where the rotation restricting convex portion 64a and the rotation restricted convex portion 62c are in contact with each other.

  That is, in the state shown in FIG. 12, the blade drive rotating plate 62 is incorporated in the base 61 (state shown in FIG. 8), and the blade member 63 is attached in this state (state shown in FIG. 9). After the state in which the plate 62 is rotated by a predetermined amount (symbol [D1] in FIG. 10) (the state in FIG. 10), and after the state in which the blade member 63 is attached from the state in FIG. 10 (the state in FIG. 11), The member 64 is further attached.

  In this case, the blade pressing member 64 is attached to the base 61 in a state where the blade driving rotary plate 62 and the plurality of blade members 63 are attached. For this purpose, first, the blade pressing member 64 is moved closer to the base 61 to which the blade driving rotary plate 62 and the plurality of blade members 63 are attached from the direction (parallel direction) along the optical axis O. At this time, the rotation restricting convex portion 64 a of the blade pressing member 64 is arranged in correspondence with the opening 61 e of the base 61. At this time, the rotation restricted convex portion 62c comes into contact with the rotation restricted convex portion 64a (see FIGS. 12 and 13).

  Thereby, the rotation restricting convex portion 64a restricts the rotation of the blade drive rotating plate 62. Therefore, the variable openings 63h formed by the plurality of blade members 63 are maintained in the “desired minimum diameter” state (see FIG. 12). In this state, the blade spring member 64 is fixed to the base 61 using screws 27g (see FIG. 12). Thus, the assembly of the aperture unit 19 of this embodiment is completed. In the state shown in FIG. 12, the state may be slightly narrowed down from the “desired minimum diameter” state in view of mechanical margin and control margin.

  In the diaphragm unit 19 of the present embodiment, the rotation of the blade drive rotating plate 62 is controlled to rotate each of the plurality of blade members 63, thereby displacing the variable opening 63h in FIG. The amount of light passing through can be adjusted.

  If the blade drive rotating plate 62 is further rotated in the direction of the arrow R1 by a predetermined amount from the state of FIG. 12, the state shown in FIG. 14 is obtained. FIG. 14 shows a state where the blade drive rotating plate 62 is further rotated by a predetermined amount in a predetermined direction from the states of FIGS. 10 and 12 to be in a “desired minimum diameter” state. In FIG. 14, the blade pressing member 64 is not shown in order to show the appearance of the plurality of blade members 63.

  Here, a predetermined amount of rotation of the blade drive rotating plate 62 in the direction of the arrow R1 is indicated by a two-dot chain line code BL1 and the same code BL2 in FIG. That is, the rotation amount [D2] when the blade driving rotary plate 62 moves from the position indicated by the two-dot chain line BL1 in FIG. 14 to the position indicated by the two-dot chain line BL2 in FIG. This rotation amount [D2] is the rotation amount of the blade drive rotating plate 62 when the variable opening 63h is displaced from the “oversized / small diameter” state to the “desired minimum diameter” state.

  Therefore, in the diaphragm unit 19 of the present embodiment, the displacement of the variable opening 63h is controlled between the “desired minimum diameter” state shown in FIG. 14 and the “open diameter” state shown in FIG.

  By the way, when the variable opening 63h is in the “desired minimum diameter” state, the plurality of blade members 63 are maximized in a state where they overlap each other, while the plurality of blade members 63 are in the “open diameter” state. The overlapping of the blade members 63 is the smallest.

  In general, when assembling the aperture unit, it is desirable to perform in a state in which the overlap between the plurality of aperture blades is small. Therefore, in the conventional aperture unit, the assembly is usually performed with the aperture blades opened. Therefore, when the diaphragm blades are in the open state, the rotation restricting projections are formed so as to protrude from the outside of the diaphragm unit as a configuration for avoiding interference between the diaphragm blades and the rotation restricting projections. There was a tendency to enlarge itself.

  In the diaphragm unit 19 of the present embodiment, when the variable opening 63h formed by the plurality of blade members 63 is in the “open diameter” state, a part of the blade member 63 is a circle of the rotation range restricting recess 61d as shown in FIG. Arrangement is made so as to cover the opening 61e at one end in the circumferential direction to avoid an increase in the size of the unit.

  When the rotation restricting convex portion 64a is assembled at a predetermined position (opening portion 61e) of the base 61 at the time of unit assembly, the state where a part of the blade member 63 covers the opening portion 61e is released, that is, This is performed when the variable opening 63h by the plurality of blade members 63 is in the “intermediate aperture” state.

  FIG. 15 shows a state where the blade drive rotating plate 62 is further rotated by a predetermined amount in the direction of the arrow R1 from the state of FIG. 14 (“desired minimum diameter” state) to set the variable aperture 63h to the “intermediate aperture” state. ing. Also in FIG. 15, the blade pressing member 64 is not shown in order to show the appearance of the plurality of blade members 63. FIG. 16 is a plan view of the diaphragm unit 19 in a state where the blade pressing member 64 is assembled in the state of FIG. 15 and the assembly is completed, as viewed from the rear surface R side.

  Here, a predetermined amount of rotation of the blade drive rotary plate 62 in the direction of the arrow R1 is indicated by a two-dot chain line code BL2 and the same code BL3 in FIG. That is, this is the rotation amount [D3] when the blade driving rotary plate 62 moves from the position of the two-dot chain line BL2 in FIG. 15 to the position of the two-dot chain line BL3 in FIG. This rotation amount [D3] is the rotation amount of the blade drive rotating plate 62 when the variable opening 63h is displaced from the “desired minimum diameter” state to the “intermediate aperture” state. In this case, since the “intermediate aperture” state is an arbitrary position between the “desired minimum diameter” state and the “open diameter” state as described above, the state shown in FIG. It only shows an example of the state.

  As shown in FIGS. 15 and 16, in the diaphragm unit 19 of the present embodiment, when the variable opening 63 h is in the “intermediate diaphragm” state, the state where the opening 61 e is covered by a part of the blade member 63. It has been released. Therefore, in this state, the rotation restricting convex portion 64a of the blade pressing member 64 can be disposed in the opening 61e of the base 61, and therefore there is no problem in assembling the aperture unit 19.

As described above, according to the above-described embodiment, in the aperture unit 19 that is an aperture adjustment device that is an exposure amount adjustment device and includes a single unit,
A plurality of blade members 63 that each form a variable opening 63h that is rotated to displace the area in order to adjust the amount of light passing through the subject light beam that passes through the imaging optical system;
The plurality of blade members 63 includes a first opening 62h and a rotation-regulated convex portion 62c that rotates in a circumferential direction around the first opening 62h and extends in the outer diameter direction. , And a plurality of blade members 63 that rotate the plurality of blade members 63 from the opening diameter of the variable opening 63h through a desired minimum diameter to an excessively small diameter that exceeds the desired minimum diameter. When,
Each of the plurality of blade members 63 is rotatably disposed around the second opening 61h, and extends in a concave shape in the circumferential direction around the second opening 61h. A base 61 having a rotation range restricting recess 61d for restricting the rotation range of 62;
An annular portion 64b having a third opening 64h and sandwiching the plurality of blade members 63 and the blade drive rotating plate 62 between the base 61 in a movable state, and a central axis of the variable opening 63h When the variable opening 63h extends in the direction parallel to O and enters the one circumferential end in the rotation range restricting recess 61d and the rotation restricted convex 62c comes into contact, the variable opening 63h becomes the excessively small diameter. A blade pressing member (64) formed with a rotation restricting convex portion 64a for preventing and restricting the rotation range of the blade driving rotary plate 62 in the range from the open diameter to the desired minimum diameter of the variable opening 63h; Comprising
The rotation range restricting concave portion 61d has the variable opening 63h having the excessively small diameter when the rotational restricted convex portion 62c is disposed at one circumferential end, and the rotational restricted convex portion 62c at the other circumferential end. When the is disposed, the variable opening 63h is set to the open diameter. When the variable opening 63h has the open diameter, one of the plurality of blade members 63 is disposed so as to cover at least one circumferential end of the rotation range restricting recess 61d.

  With such a configuration, the rotation restriction convex portion 64 a provided on the blade pressing member 64 is brought into contact with the rotation restricted convex portion 62 c of the blade driving rotation plate 62, thereby restricting the rotation range of the blade driving rotation plate 62. In addition, in the aperture unit 19 that is an exposure amount adjusting device and an aperture device that prevents the blade drive rotating plate 62 from rotating in the direction of the optical axis O while ensuring the rotation around the optical axis O, the number of components is reduced. The aperture unit 19 can be downsized in the radial direction without increasing.

In this configuration, when the variable openings 63h formed by the plurality of blade members 63 are in an open state, the rotation regulating convex portion 64a and the blade member 63 interfere with each other, so that the blade pressing member 64 is incorporated into the base 61. I can't.
Therefore, in the aperture unit 19 of the present embodiment, the variable opening 63h formed by the plurality of blade members 63 is slightly narrowed from the open diameter, that is, the “open diameter” state and the “desired” The unit is assembled after the “intermediate aperture” state between the “minimum diameter” state. This is because in the “intermediate aperture” state, interference between the rotation restricting convex portion 64a and the blade member 63 can be avoided.

  By devising the assembly procedure after devising such a configuration, while taking the configuration almost the same as the conventional one, without increasing the number of parts and avoiding complicated configuration, It is possible to provide an aperture unit 19 (aperture device) that is an exposure amount adjustment device that can be downsized.

  The present invention is not limited to the above-described embodiments, and it is needless to say that various modifications and applications can be implemented without departing from the spirit of the invention. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if several constituent requirements are deleted from all the constituent requirements shown in the above-described embodiment, if the problem to be solved by the invention can be solved and the effect of the invention can be obtained, this constituent requirement is deleted. The configured structure can be extracted as an invention. Furthermore, constituent elements over different embodiments may be appropriately combined. The invention is not limited by the specific embodiments thereof, except as limited by the appended claims.

  The present invention is not limited to only an imaging device specialized for the imaging function, and other forms of electronic devices having an imaging function, such as a digital camera, a movie camera, a mobile phone, a smartphone, an electronic notebook, an electronic dictionary, It can be widely applied to various electronic devices with an imaging function such as a portable information terminal, a personal computer, a tablet terminal device, a game device, a television receiver, a clock, a navigation device using GPS (Global Positioning System). it can.

  Further, the same applies to an electronic device having a function of acquiring an image using an imaging device and displaying the acquired image using a display device, for example, an observation device such as a telescope, binoculars, monoculars, and a microscope. Can be applied.

  In addition to industrial or medical observation devices such as endoscopes and microscopes, the present invention can also be applied to imaging devices such as surveillance cameras and in-vehicle cameras.

  In addition to these, the present invention can be similarly applied to, for example, a projection-type image display apparatus that enlarges and projects an image using, for example, a transmissive liquid crystal display apparatus.

1 ... Lens barrel,
11 …… Front decorative ring,
12 ... Hood mounting ring,
13: Front exterior ring,
16 …… Exterior rear tube,
17: Lens side mount,
18 …… Contact retaining ring,
19 …… Aperture unit,
19h …… Opening,
20 …… Scivil Unit Osaeita,
21 …… Focus ring,
22 …… 2 group lens frame,
23 …… 3 group lens frame,
24 …… 4 group lens frame,
25 …… Inner fixed cylinder,
26 …… Double-sided tape,
27a, 27b, 27c, 27e, 27f, 27g, 27h ... screw,
28 …… Aperture drive motor,
28a ...... Pinion gear,
29 …… Lens substrate,
29a ...... Connector,
30: Flexible printed circuit board,
31 …… First lens group,
32 …… Second lens group,
33 …… Third lens group,
34 ... Fourth lens group,
61 …… Base,
61a .... Annular shape part,
61b ... peripheral wall,
61c .. fixed part,
61d …… Rotation range regulating recess,
61d1: circumferential side surface,
61e …… Opening part,
61f …… Bayonet opening,
61g …… Bane support shaft,
61h …… Opening,
62 ... blade drive rotating plate,
62a …… Bayonet locking claw,
62b ...... the locking arm part,
62c: Rotation restricted convex part,
62d: sector gear,
62h …… Opening,
63 …… Bane member,
63a …… Rotating hole,
63b …… Pin,
63h …… Variable aperture,
64 ....
64a ...... rotation restricting convex part,
64b ...... annular part,
64c ...... window,
64h ...... opening,
65 …… Coil spring,

Claims (3)

In the exposure adjustment device,
In order to adjust the amount of light passing through, a plurality of blade members that each form a variable opening that rotates to change the area;
A first opening, and a rotation-regulated convex portion that rotates in a circumferential direction around the first opening and extends in the outer diameter direction. A blade driving rotary plate that rotationally drives each of the plurality of blade members between the minimum diameter and an excessively small diameter exceeding the desired minimum diameter;
Each of the plurality of blade members is rotatably disposed around the second opening, and extends in a concave shape in the circumferential direction centering on the second opening. A base having a rotation range restricting recess to restrict;
An annular portion having a third opening and sandwiching the plurality of blade members and the blade driving rotary plate in a movable state between the base and the base, and extending in a direction parallel to the central axis of the variable opening The variable opening is prevented from becoming an excessively small diameter when entering the circumferential end in the rotational range restricting concave portion and the rotational restricted convex portion comes into contact, and the variable opening is separated from the open diameter. A blade pressing member formed with a rotation restricting convex portion for restricting the rotation range of the blade drive rotating plate in a range up to the desired minimum diameter;
Comprising
The rotation range restricting concave portion has the variable opening as the excessively small diameter when the rotation restricted convex portion is arranged at one circumferential end, and the rotation restricted convex portion is arranged at the other circumferential end. Sometimes the variable opening is the opening diameter,
An exposure adjustment apparatus, wherein one of the plurality of blade members is disposed so as to cover at least one circumferential end of the rotation range restricting recess when the variable opening has the opening diameter.   2. The exposure amount adjusting device according to claim 1, wherein the exposure amount adjusting device is a diaphragm device.   3. The exposure amount adjustment device according to claim 1, wherein the exposure amount adjustment device is composed of a single unit.

Images