JP5461278B2 - Camera aperture device - Google Patents

Description

  The present invention relates to a camera diaphragm in which a plurality of aperture blades cooperate to form an aperture opening and are simultaneously reciprocated in the same direction by an aperture drive ring to change the size of the aperture opening. Relates to the device.

  A plurality of aperture blades are simultaneously rotated in the same direction by an aperture drive ring to change the size of the aperture aperture formed in cooperation (usually a multi-stage aperture device). However, in the case of this type of diaphragm device, a plurality of diaphragm blades are located in the blade chamber formed between the ground plate and the cover plate with respect to the ground plate. Usually, the connecting pins provided on them are individually fitted in a plurality of cam grooves formed on the aperture drive ring. On the other hand, the diaphragm drive ring is disposed in a concave portion formed in an annular shape around the optical axis on the blade chamber side surface of the base plate, and when it is reciprocally rotated, the cam groove causes the above-mentioned connecting pin to move. By pushing, the diaphragm blades are reciprocally rotated.

  In addition, the overlapping arrangement relationship between the diaphragm blades and the diaphragm drive ring is that the diaphragm blades may be disposed between the diaphragm drive ring and the main plate, but recently, for reasons such as ease of assembly work, It is often arranged between the aperture drive ring and the cover plate. Furthermore, the aperture device having such a configuration may be unitized alone, but when used in a compact camera, it is usually unitized together with a shutter device. The ground plate and the cover plate are partitioned by an intermediate plate, and the space between the intermediate plate and the cover plate is a blade chamber of the shutter blade. In recent diaphragm devices, the diaphragm driving ring is usually reciprocally rotated by a stepping motor, but it is not without the one that is manually rotated.

  By the way, the diaphragm blades in this type of diaphragm device have an elongated shape as a whole and are attached to the base plate in the vicinity of one end (hereinafter referred to as the base end), so that the exposure aperture is fully open. When the aperture is made smaller from the position (maximum aperture opening control position), it is configured to enter the exposure aperture from the other end (hereinafter referred to as the front end) and approach the center of the optical axis. Therefore, if the diaphragm blades are simply stacked in order, each diaphragm blade has an overlap amount with the aperture drive ring and an overlap amount with the adjacent diaphragm blades when entering the exposure opening from the tip side thereof. As the number decreases, the posture becomes unstable, and the tip tends to fluctuate in a direction parallel to the optical axis. As a result, the tip surfaces of adjacent aperture blades are not easily in contact with each other, and a smaller aperture opening cannot be formed properly. Such a phenomenon becomes more prominent as the aperture device has a larger exposure aperture.

  Therefore, a method of assembling the aperture blade, which is usually called a braided type, is known. In this assembly method, all the diaphragm blades are assembled so as to be arranged between the other two diaphragm blades. When this assembly method is used, as the aperture becomes smaller, the tip of each aperture blade becomes intertwined with each other and the force to support it increases. Will not occur. Patent Document 1 below describes a camera diaphragm device that employs such a knitting type.

  However, when this braided type is adopted, the above-mentioned wobbling can be prevented, but the aperture of the aperture cannot be made too small. It is greatly deflected, and the tip of them rises to one of the directions parallel to the optical axis. Eventually, large stagnation occurs between them. In order to increase the rotation, the rotation in the reverse direction cannot be performed smoothly. Therefore, even in such a braided diaphragm device, various devices have been conventionally made in order to be able to stably change a small diaphragm aperture, but one example is as follows. It is described in Patent Document 2 below.

JP 2003-195389 A JP 2008-134283 A

  By the way, recent users have come to like multi-function cameras and high-function cameras, for example, cameras that have made it possible to shoot beautifully dark subjects without using a flash device, and compact cameras. But I've come to like cameras that can shoot movies. For this reason, in the case of a diaphragm device, it is not necessary to reduce the cost as in the conventional case, but a functionally superior one is required. In the case of a braided diaphragm device, a smaller diaphragm is required. There has been a strong demand for a device that can stably control the opening.

  Therefore, looking at the diaphragm device described in Patent Document 2 from such a viewpoint, in the case of this diaphragm device, a smaller diaphragm opening can be obtained more stably than the conventional diaphragm device. Thus, the above-described requirements can be sufficiently met. However, in the case of this diaphragm device, each of the ground plane and the diaphragm drive ring is inclined with respect to a plane perpendicular to the optical axis to form a plurality of slopes, and by sliding the slopes of both, The diaphragm drive ring is configured to move in the direction along the optical axis. Therefore, the number of parts does not increase compared to the conventional diaphragm device, but the main plate and the diaphragm drive ring must be processed into a special shape, and the diaphragm drive ring is caused to make an unprecedented movement. Therefore, it is not necessarily preferable from the viewpoint of production.

  The present invention has been made in order to solve such problems, and an object of the present invention is to obtain a diaphragm aperture smaller than the conventional one simply by devising the configuration of a plurality of diaphragm blades. It is an object of the present invention to provide a braided camera diaphragm device.

  In order to achieve the above object, a diaphragm device for a camera according to the present invention includes a ground plane having a circular opening centered on the optical axis and a recess formed around the opening, and an optical axis. A diaphragm drive ring having a plurality of elongated cam grooves formed at substantially equal angular intervals around the optical axis and reciprocally rotated around the optical axis in the recess by the driving means, and around the optical axis A plurality of first sheets which are arranged at substantially equal angular intervals and are rotatably attached to the base plate in the vicinity of one end in the length direction and have a long and slender cam groove at a substantially central portion in the length direction. The diaphragm blades are arranged at substantially equal angular intervals with the optical axis as the center, and are individually superposed on the first diaphragm blades so as to form a pair. Make a pair of connecting pins that are mounted rotatably and provided in the approximate center. A plurality of second diaphragm blades that are thicker than the first diaphragm blades inserted into both the cam grooves of the first diaphragm blades and the cam grooves of the diaphragm drive ring, and Each of the pair of diaphragm blades is disposed between the other two adjacent pair of diaphragm blades, and when the diaphragm drive ring is rotated in the direction from the maximum to the minimum, the halfway of the diaphragm drive ring. The diaphragm aperture is formed by the cooperation of the plurality of second diaphragm blades, and then the diaphragm aperture is formed by the cooperation of the plurality of first diaphragm blades up to the minimum diaphragm aperture.

  In that case, it is preferable that the first diaphragm blades are arranged so as to overlap the diaphragm drive ring side with respect to the paired second diaphragm blades. Further, the first diaphragm blade is rotatably attached to the base plate by fitting a hole formed in the first diaphragm blade to a shaft erected on the base plate, The second diaphragm blade has a hole formed in the base plate with a shaft erected on the second diaphragm blade in the vicinity of the pair of the first diaphragm blades rotatably attached to the base plate. It is practical to be attached so as to be rotatable with respect to the main plate by being fitted to the base plate. Further, when the second diaphragm blade is formed so that the region along the diaphragm opening forming edge becomes thinner toward the diaphragm opening forming edge, it becomes easier to form a small diaphragm opening more suitably. .

  According to the present invention, a conventional braided diaphragm device is additionally provided with a plurality of diaphragm blades thinner than the conventional diaphragm blades, and the thin diaphragm blades are paired with the conventional diaphragm blades. By operating and relatively operating, a diaphragm opening larger than the predetermined diaphragm opening is formed by the cooperation of a plurality of diaphragm blades having the same thickness as the conventional one, than the predetermined diaphragm opening. The smaller aperture opening can be formed by the cooperation of a plurality of aperture blades that are thinner than the conventional aperture blades. A feature of the present invention is that it is possible to suitably form a diaphragm aperture smaller than the conventional one by the plurality of diaphragm blades.

It is a disassembled perspective view of an Example. It is the top view of the Example which showed the control state of the largest aperture opening. It is the top view which showed the state narrowed down from the state of FIG. 2 to the middle. FIG. 4 is a plan view showing a state further narrowed down than the state of FIG. 3. It is the top view of the Example which showed the control state of the minimum aperture stop. It is sectional drawing which showed the state of FIG. 5 typically.

  Embodiments of the present invention will be described with reference to the illustrated examples. The camera aperture device of the present invention can be configured as a single aperture device or as a unitized aperture device together with the shutter device, but the embodiment is configured as a single aperture device. is there. In each drawing, the illustration of the mounting structure to the camera is omitted. Moreover, in FIGS. 1-5, illustration of the cover board 2 shown by FIG. 6 and illustration of the attachment structure of the cover board 2 with respect to the ground plane 1 are abbreviate | omitted.

  First, the configuration of this embodiment will be described. The diaphragm device for a camera of this embodiment forms a blade chamber between the main plate 1 and the cover plate 2 shown only in FIG. The base plate 1 is made of a synthetic resin, and a circular opening 1a centering on the optical axis is formed at the center thereof. The cover plate 2 is made of synthetic resin or metal and has substantially the same outer shape as that of the base plate 1, and a circular opening 2a centered on the optical axis is formed at the center thereof. Yes. The exposure aperture (that is, the maximum aperture diameter) that is the aperture for the subject optical path is normally restricted by the smaller one of the apertures 1a and 2a, but in FIG. Both diameters are shown to be the same.

  On the surface of the main plate 1 on the blade chamber side, a recess 1b is formed in an annular shape with the optical axis as the center. On the substantially circular side wall of the recess 1b, guide portions 1c having concave arcuate surfaces are formed at depths from the edge to the bottom of the recess 1b at five angular positions centered on the optical axis. In addition, a retaining portion 1d having a convex arcuate surface is formed at a thickness from the edge of the concave portion 1b to a predetermined depth at three angular positions around the optical axis. Furthermore, arc-shaped escape holes 1e are also formed on the bottom surface of the recess 1b at six locations at substantially equal angular intervals with the optical axis as the center. In the case of the present embodiment, the escape holes 1e do not penetrate the ground plate 1, but may be formed so as to penetrate.

  Further, on the surface of the base plate 1 on the blade chamber side, blade attachment holes 1f are formed at approximately six equiangular intervals centered on the optical axis so as to surround the recess 1b, and these blade attachment holes 1f are formed. Each blade attachment shaft 1g is erected at substantially equal angular intervals around the optical axis. Furthermore, a circular recess 1h deeper than the recess 1b is formed on the surface of the base plate 1 on the blade chamber side so that a little less than half is applied to the recess 1b. The two-stage gear 3 is rotatably attached. Although not shown, the recess 1h actually has a window on a part of its side wall and communicates with the surface on the opposite side of the main plate 1, and is attached to the surface on the opposite side of the main plate 1. A gear that is rotated by the stepping motor is engaged with the larger gear portion of the two-stage gear 3.

  In the recess 1b, the diaphragm drive ring 4 is disposed so that the outer peripheral surface thereof can be slidably contacted with the five guide portions 1c. The diaphragm drive ring 4 has six elongated cam grooves 4a formed at substantially equal angular intervals around the optical axis, and a partial gear formed on the outer peripheral surface over a predetermined angular range. It has the part 4b and the notch part 4c formed in three places. In this embodiment, the inner diameter of the aperture driving ring 4 is the same as the diameter of the opening 1a, but the present invention is not necessarily required to do so. The inner diameter may be larger than the diameter of the opening 1a, or the inner diameter may be smaller than the diameter of the opening 1a to regulate the exposure opening (maximum aperture opening).

  The diaphragm drive ring 4 is dropped into the recess 1b so that the three notches 4c are aligned with the positions of the three retaining portions 1d, and the partial gear portion 4b is The small gear portion of the two-stage gear 3 is engaged with the gear. For this reason, the diaphragm drive ring 4 is reciprocally rotated in a predetermined rotation angle range via the two-stage gear 3 by reciprocal rotation of the stepping motor. The positions of the two notches 4c are set so as not to overlap with the positions of the three retaining portions 1d.

  After the diaphragm drive ring 4 is assembled in this way, in the case of the present embodiment, a total of 12 diaphragm blades are assembled. That is, the diaphragm device of this embodiment has six diaphragm blades 5 having the same shape and the same thickness, and six diaphragm blades 6 that are considerably thinner than the diaphragm blades 5 and have the same shape. I have. The diaphragm blade 5 has a blade shaft 5a erected in the vicinity of the base end, which is one end in the length direction, and a connection pin 5b is provided at a substantially central portion in the length direction. Further, the diaphragm blade 6 has a mounting hole 6a formed in the vicinity of the base end which is one end in the length direction, and a cam groove 6b is formed in a substantially central portion in the length direction.

  Further, in the case of the present embodiment, as can be seen from the operation description to be described later, in the diaphragm blade 5, a considerable edge on the opening portion 1 a side becomes a diaphragm opening forming edge, and the diaphragm blade 6 has an opening portion in the vicinity of the tip. A part of the edge on the 1a side becomes a diaphragm opening forming edge. Further, the diaphragm blade 5 faces the aperture opening forming edge by making the surface along the aperture opening forming edge an inclined surface on the cover plate 2 side as shown in FIG. It is formed to become thinner gradually. However, the surface on the ground plane 1 side may be an inclined surface. The diaphragm blades 5 and 6 having such a shape are stacked one by one so as to form a pair, and a total of six pairs of diaphragm blades are assembled to the main plate 1 as follows.

  First, the diaphragm blades 5 and 6 of each pair are arranged such that the diaphragm blade 6 is disposed on the diaphragm drive ring 4 side and the diaphragm blade 5 is disposed on the cover plate 2 side. 6a is rotatably fitted to the blade mounting shaft 1g of the base plate 1, but the diaphragm blade 5 has its blade shaft 5a rotatably fitted to the blade mounting hole 1f of the base plate 1. At the same time, the connecting pin 5 b is inserted into the cam groove 6 b of the diaphragm blade 6 and the cam groove 4 a of the diaphragm drive ring 4 in this order. The six pairs of diaphragm blades are assembled to the main plate 1 such that any one pair of diaphragm blades is overlapped between the other two pairs of diaphragm blades.

  In addition, since the thickness of the aperture blade 6 of this embodiment is quite thin as described above, it is very easy to bend. In other words, when the diaphragm blade 6 is configured to change the diaphragm opening with only six diaphragm blades 6, even when the diaphragm blade is assembled in a braided manner, when controlling a small diaphragm aperture, The thickness is such that a substantially central portion is bent and an appropriate aperture opening cannot be controlled. Therefore, in this embodiment, after assembling all the diaphragm blades, when transporting them in that state, or when attaching another member, etc., each pair of diaphragm blades 6 is not damaged. The diaphragm blades 5 and 6 are assembled with the thinner diaphragm blade 6 facing the diaphragm drive ring 4 side. However, the present invention is not limited to such an assembly method, and may be assembled such that the thin diaphragm blade 6 is on the cover plate 2 side.

  In the case of the present embodiment, each pair of diaphragm blades 5 and 6 must be such that the pair of diaphragm blades 5 and 6 adjacent to each other in the counterclockwise direction is on the cover plate 2 side. Are assembled. However, the pair of diaphragm blades 5 and 6 adjacent to each other in the clockwise direction may be assembled such that they are always on the cover plate 2 side. Further, the diaphragm blade 5 of the present embodiment has its blade shaft 5a fitted in the blade mounting hole 1f of the main plate 1. However, like the diaphragm blade 6, a hole is formed instead of the blade shaft 5a. It does not matter even if the hole is fitted to the blade mounting shaft standing on the base plate. Further, the diaphragm blade 6 may also be configured such that, like the diaphragm blade 5, a blade shaft is erected in place of the mounting hole 6a, and the blade shaft is fitted into a blade mounting hole formed in the base plate. . Further, in the case of the diaphragm device of the present embodiment, six pairs of diaphragm blades 5 and 6 are provided, but it goes without saying that the number may be five or seven.

  Next, the operation of the present embodiment will be described with reference to FIGS. 2 to 6. In FIGS. 3 to 5, among the six pairs, one pair of apertures attached to the left position in each figure. Only the blades 5 and 6 are marked with members and parts. First, FIG. 2 shows a state in which the six aperture blades 5 and 6 fully open the opening 1a, that is, a control state of the maximum aperture opening. At this time, the connecting pin 5b of the diaphragm blade 5 is in the vicinity of the end closer to the opening 1a in the cam groove 6b formed in the diaphragm blade 6, and in the cam groove 4a of the diaphragm drive ring 4. Then, it exists in the vicinity of the end far from the opening part 1a.

  If the subject light is darker than the predetermined brightness, the image is taken as it is. However, when the subject light is brighter than the predetermined brightness, the stepping motor rotates to rotate the two-stage gear 3 counterclockwise. Accordingly, the diaphragm drive ring 4 is rotated in the clockwise direction, so that the edge of the cam groove 4a pushes the connecting pin 5b to rotate the six diaphragm blades 5 counterclockwise, and at the same time, the connecting pin Since 5b pushes the edge of the cam groove 6b, the six diaphragm blades 6 are simultaneously rotated counterclockwise. Therefore, all the 12 diaphragm blades 5 and 6 are rotated counterclockwise, and enter the opening 1a from their tip ends.

  By the way, in the case of the present embodiment, the pair of diaphragm blades 5 and 6 are rotated at different positions, so that the distances from the rotation positions to the connecting pin 5b are different. The cam groove 6b of the diaphragm blade 6 into which the connecting pin 5b is inserted is formed in a unique shape. Therefore, when the diaphragm blades 5 and 6 are simultaneously rotated counterclockwise as described above, their rotational speeds (rotational angles) are different, and their rotational speeds are also relatively changed. Therefore, in the case of the present embodiment, when the diaphragm blades 5 and 6 are both started to rotate counterclockwise from the state of FIG. 2, the diaphragm blade 5 enters the opening 1 a before the diaphragm blade 6. Intruding, the apertures are formed by the cooperation of the six aperture blades 5, and the size is reduced.

  After that, when the aperture device of this embodiment is employed in a still camera, the rotation of the stepping motor stops when a predetermined aperture opening is obtained, and shooting is performed, and the aperture device is employed in a movie camera. If this is the case, the aperture of the aperture will be changed so that shooting is always performed under proper exposure conditions by the forward or reverse rotation of the stepping motor in response to changes in the subject light. . FIG. 3 shows a state where the size of the aperture opening is closer to the aperture opening than the middle size of the control range as described above. In the case of this embodiment, FIG. Even in this state, the aperture opening is formed by the cooperation of the six aperture blades 5. That is, in the case of the present embodiment, all the aperture openings are formed by the cooperation of the six aperture blades 5 from the state of FIG. 2 to the state of FIG.

  When the diaphragm drive ring 4 is further rotated in the clockwise direction from the state shown in FIG. 3, the diaphragm blades are caused by the action of the cam grooves 4a of the diaphragm drive ring 4 and the cam grooves 6b of the diaphragm blades 6. The rotational speed of 5 in the counterclockwise direction suddenly decreases, and the rotation of the aperture blade 6 in the counterclockwise direction rapidly increases. Therefore, thereafter, the vicinity of the tip of the diaphragm blade 6 precedes the optical axis rather than the vicinity of the tip of the diaphragm blade 5, and the diaphragm aperture is formed by the cooperation of the six diaphragm blades 6. Will come to be. FIG. 4 shows an initial stage state in which the diaphragm aperture is formed by the cooperation of the six thin diaphragm blades 6 as described above.

  When the diaphragm drive ring 4 is further rotated in the clockwise direction from the state shown in FIG. 4, the distance between the edges on the optical axis side at the distal ends of the pair of diaphragm blades 5 and 6 becomes larger. As they go up, their edges gradually rise to the ground plane 1 side. Further, when the swell is further increased, stagnation occurs in the thicker six diaphragm blades 5, and when the diaphragm drive ring 4 is reversed counterclockwise, the diaphragm blades 5 do not operate smoothly. The limit state is the state shown in FIGS. That is, the states of FIG. 5 and FIG. 6 are control states of the minimum aperture opening in the present embodiment.

  In the case of the present embodiment, as described above, each pair of diaphragm blades 5 and 6 corresponds to the pair of diaphragm blades 5 and 6 adjacent in the counterclockwise direction in FIG. However, it is assembled so as to be on the cover plate 2 side. Therefore, the diaphragm blades 6 rise to the base plate 1 side according to the deflection of the paired diaphragm blades 5 as described above, but in FIG. 2, a pair of diaphragms adjacent in the clockwise direction. When the blades 5 and 6 are always assembled so that they are on the cover plate 2 side, the diaphragm blades 6 of the pair of diaphragm blades 5 and 6 on the cover plate 2 side are immediately before that. In response to the deflection of the diaphragm blade 5 of the pair of assembled diaphragm blades 5 and 6, the cover plate 2 rises.

  In this way, in the case of the present embodiment, when the aperture opening is made smaller in this way, in order to slow down the stagnation of the operation of the six aperture blades 5 as much as possible, as described above, Although an inclined surface is formed in a region along the aperture opening forming edge to make it as easily bent as possible, the state shown in FIGS. 5 and 6 is still the limit. Therefore, if it is assumed that the thin six diaphragm blades 6 are not provided in this embodiment, as can be seen by comparing FIG. 4 and FIG. Even the size of the aperture stop of 4 cannot be controlled. However, in the case of the present embodiment, the aperture opening forming edge of the aperture blade 6 bent according to the deflection of the aperture blade 5 is closer to the optical axis than the aperture opening forming edge of the aperture blade 5. Since it is formed, an extremely small aperture as shown in FIG. 5 can be suitably formed.

  In this way, when the aperture opening is controlled and photographing is completed, the stepping motor rotates the two-stage gear 3 in the clockwise direction, so that the aperture driving ring 4 is rotated in the counterclockwise direction, and all the aperture blades 5, 5 are rotated. 6 is simultaneously rotated clockwise. These rotations stop when the aperture blades 5 and 6 fully open the opening 1a, and prepare for the next photographing in the state of FIG. The operation of the present embodiment has been described on the assumption that FIG. 2 is in a state before the start of photographing. However, depending on the design specifications of the camera, any state may be set to the state before starting the photographing. Needless to say. In the case of a movie camera, the aperture drive ring 4 may not be rotated at the stage of shooting, but may be rotated in any direction from the state at the time of the next shooting.

  In the present embodiment, the pair of diaphragm blades 5 and 6 are rotatably mounted at different positions on the main plate 1. For example, the attachment hole 6 a of the diaphragm blade 6 is replaced with the blade of the diaphragm blade 5. It is also possible to fit the shaft 5a. In that case, it goes without saying that at least the aperture blade 6 must have a shape different from that of the present embodiment. Furthermore, as already described, the present invention can also be applied to an aperture device and a shutter device that are combined into one unit. As an example in that case, two blade chambers are configured by partitioning between the base plate 1 and the cover plate 2 of the present embodiment with an intermediate plate, and between the base plate 1 and the intermediate plate as in the present embodiment. A shutter blade is arranged in the blade chamber between the intermediate plate and the cover plate 2 and an actuator for opening and closing the shutter blade is attached to the surface of the base plate 1 to which the stepping motor is attached. It is common to make it.

DESCRIPTION OF SYMBOLS 1 Ground plate 1a, 2a Opening part 1b, 1h Concave part 1c Guide part 1d Retaining part 1e Relief hole 1f Blade attachment hole 1g Blade attachment shaft 1i Shaft 2 Cover plate 3 Two-stage gear 4 Diaphragm drive ring 4a, 6b Cam groove 4b Partial gear Part 4c Notch part 5, 6 Diaphragm blade 5a Blade shaft 5b Connecting pin 6a Mounting hole

Claims (4)

  A ground plane having a circular opening centered on the optical axis and a recess formed around the opening, and a plurality of elongated cam grooves formed at substantially equal angular intervals around the optical axis. A diaphragm driving ring that is reciprocally rotated around the optical axis within the recess by the driving means, and is arranged at substantially equal angular intervals around the optical axis and has one end in the length direction near the base plate And a plurality of first diaphragm blades having a long and slender cam groove at a substantially central portion in the length direction, and arranged at substantially equal angular intervals around the optical axis. The first diaphragm blades are individually superposed so as to form a pair, and a pair of connecting pins provided in the substantially central portion are rotatably attached to the base plate in the vicinity of one end in the longitudinal direction. The first aperture blade cam groove and the aperture drive ring cam groove A plurality of second diaphragm blades that are thicker than the first diaphragm blades inserted in both of the two diaphragm blades, and each of the pair of diaphragm blades is adjacent to the other two pairs of diaphragms. When the diaphragm driving ring is rotated in a direction that minimizes the diaphragm opening from the maximum to the minimum, the diaphragm opening is formed by the cooperation of a plurality of the second diaphragm blades until halfway. Then, a diaphragm aperture is formed by cooperation of a plurality of the first diaphragm blades up to the minimum diaphragm aperture.   2. The camera diaphragm device according to claim 1, wherein the first diaphragm blades are arranged so as to overlap the diaphragm driving ring side with respect to the paired second diaphragm blades.   The first diaphragm blade is rotatably attached to the ground plate by fitting a hole formed in the first diaphragm blade to a shaft standing on the ground plate, The diaphragm blades are fitted in a hole formed in the base plate at a position near the pair of the first diaphragm blades that is rotatably attached to the base plate. The diaphragm device for a camera according to claim 1, wherein the diaphragm device is rotatably attached to the base plate by combining them.   The camera according to any one of claims 1 to 3, wherein the second diaphragm blade is formed such that a region along the diaphragm opening forming edge becomes thinner toward the diaphragm opening forming edge. Throttle device.

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