JP2010128357A - Diaphragm device for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm device for a camera, which is configured to change a diaphragm aperture by rotating backward and forward a plurality of diaphragm blades having a blade shaft and a coupling pin on the same plane simultaneously in the same direction by a diaphragm driving ring, and which has large degree of freedom in design and is made compact. <P>SOLUTION: Six blade mount holes 1d are formed on a surface of a bottom board 1 facing the diaphragm driving ring 6. Six cam grooves 6a and six clearance parts 6b are formed on the diaphragm driving ring 6. The six diaphragm blades 7 have the blade shafts 7a and the coupling pins 7b on the same plane, and are arranged between the diaphragm driving ring 6 and a cover plate 2. After the blade shaft 7a is inserted into the clearance part 6b, it is fit to the blade mount hole 1d to be rotatable, and the coupling pin 7b is inserted into the cam groove 6a. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  According to the present invention, by rotating the diaphragm drive ring in a predetermined angle range, a plurality of diaphragm blades are simultaneously rotated in the same direction to change the size of the diaphragm aperture formed by their cooperation. The present invention relates to an aperture device for a camera.

  In the diaphragm device for a camera, when the diaphragm drive ring reciprocates within a predetermined rotation angle range around the optical axis, a plurality of pieces attached to the base plate at predetermined angular intervals around the optical axis The diaphragm blades are rotated in the same direction at the same time, and the size of the diaphragm opening is changed continuously or stepwise by their cooperation. Are described in Patent Document 1 and Patent Document 2 below.

  In the diaphragm device for a camera described in Patent Document 1, a plurality of diaphragm blades are arranged between a base plate and a diaphragm drive ring, and a blade shaft provided on one surface is used as a diaphragm drive ring. In a region facing the blade, it is rotatably fitted in each blade mounting hole formed in the base plate, and a connecting pin provided on the other surface is inserted into each cam groove formed in the aperture drive ring. The configuration is

  Further, in the diaphragm device for a camera described in Patent Document 2, a plurality of diaphragm blades are arranged between a cover plate that forms a blade chamber between the diaphragm and the diaphragm drive ring, A blade shaft provided on one surface is rotatably fitted in each blade mounting hole formed in the base plate in a region in a radial direction from the diaphragm drive ring as viewed from the optical axis, and a connection provided on the same surface The pin is inserted into each cam groove formed in the aperture drive ring.

  The present invention relates to a camera diaphragm device belonging to the configuration described in Patent Document 2 out of two typical configurations.

JP-A-2005-37828 JP 2003-57715 A

  By the way, as described above, the diaphragm device for a camera described in Patent Document 1 includes a plurality of diaphragm blades arranged between the main plate and the diaphragm drive ring, and a blade shaft provided on one surface. Is fitted into each blade mounting hole formed in the base plate in a region facing the aperture driving ring. In such a configuration, the diaphragm blades are operated in the region from the optical axis to the outer diameter of the diaphragm drive ring. It is possible to reduce the size of the drive ring to the vicinity of the housing portion, and it can be said that the configuration is suitable for downsizing of the apparatus.

  However, this configuration is not an advantageous configuration in terms of assembly work. That is, there is no problem in the operation of attaching the diaphragm blades to the blade attachment shafts of the main plate because the blade shafts are simply fitted into the blade attachment holes one by one. However, after attaching a plurality of diaphragm blades in this way, when attaching the diaphragm drive ring, the plurality of diaphragm blades that are in an unstable state are lowered from above, and their connecting pins are connected to a plurality of cams. It must be inserted into the groove at once. Therefore, the rotational positions of the plurality of diaphragm blades must be aligned in advance, and when attaching the diaphragm drive ring, the predetermined positions of the plurality of cam grooves are aimed at the plurality of connecting pins. There is a need.

  On the other hand, in the camera diaphragm device described in Patent Document 2, as described above, a plurality of diaphragm blades provided with a blade shaft and a connecting pin on the same surface are provided between the cover plate and the diaphragm drive ring. The blade shaft is fitted in the blade mounting hole in a region in the radial direction from the diaphragm drive ring as viewed from the optical axis. Therefore, the diaphragm blade is attached to the blade mounting hole of the base plate in the order of the blade shaft, one by one with respect to the blade mounting hole formed in the base plate and the cam groove of the diaphragm drive ring previously attached to the base plate. It just fits the connecting pin. Therefore, as compared with the case of the camera diaphragm device described in Patent Document 1, the assembling work is much easier.

  However, in such a configuration, the plurality of diaphragm blades are attached to the base plate in a region in the radial direction from the diaphragm drive ring as viewed from the optical axis. Compared to, the configuration is not suitable for downsizing. And the aperture blade per sheet also becomes larger. In addition, when the motor is configured as described in Patent Document 2, due to the presence of gears that are related members, the attachment positions of the diaphragm blades corresponding to the number must be examined, and the design There is difficulty in freedom.

  The present invention has been made in order to solve such problems, and an object of the present invention is to provide a plurality of diaphragm blades having a blade shaft and a connecting pin on the same surface, the cover plate and the diaphragm drive. It is arranged between the ring and each blade shaft is rotatably fitted to the blade mounting shaft of the main plate so that the connecting pin is inserted into the cam groove of the aperture drive ring. Regardless, it is an object of the present invention to provide an aperture device for a camera that has a high degree of freedom in design and can be downsized as a whole.

  In order to achieve the above object, the diaphragm device for a camera of the present invention comprises a blade chamber between the cover plate and an annular recess centered on the optical axis on the surface of the blade chamber. There are the same number of ground plates in which the plurality of blade mounting holes are formed at substantially equal angular intervals around the optical axis, the plurality of cam grooves and the plurality of relief portions at the same angular intervals as the blade mounting holes. The diaphragm drive ring is rotatably disposed in the recess, and is disposed between the diaphragm drive ring and the cover plate, and has a blade shaft and a connecting pin on the same surface. A plurality of diaphragm blades which are rotatably fitted in the blade mounting holes after the shaft is inserted into the relief portion and the connecting pins are inserted into the cam grooves, and the diaphragm drive attached to the base plate By rotating the ring back and forth, the plurality of diaphragm blades can be Rotated in the same direction so as it comprises a driving means for changing the size of the aperture stop by their cooperation, the.

  In this case, a gear is rotatably attached to the base plate between the cover plate and a partial gear portion meshing with the gear is formed on the outer peripheral portion of the aperture driving ring, and the driving means Is a stepping motor that reciprocally rotates the gear, it becomes practical.

  In the present invention, a plurality of diaphragm blades have a blade shaft and a connecting pin on the same surface, and are arranged between the cover plate and the diaphragm drive ring, and each blade shaft is connected to a blade mounting hole of the main plate. In the camera diaphragm device having a structure in which the connecting pin is inserted into the cam groove of the diaphragm drive ring, a relief portion is formed in the diaphragm drive ring, and the blade shaft of the diaphragm blade is After being inserted into the relief part, it is fitted into the blade mounting hole formed in the main plate, so that the assembly work is easy as in the past, and the degree of freedom in design is increased and the size is reduced. There is a feature to get.

  Embodiments of the present invention will be described with reference to the illustrated examples. As is well known, the camera diaphragm device may be configured as a unit only with the diaphragm device, but may be configured as one unit together with the shutter device or the like. Therefore, the diaphragm device according to the embodiment described below is configured only by the diaphragm device as a unit. However, the camera diaphragm device of the present invention includes such a diaphragm device united with the shutter device. It is. FIG. 1 is a plan view of the embodiment showing the control state of the intermediate aperture, and FIG. 2 is a cross-sectional view for explaining the overlapping state of the members constituting the embodiment. In FIG. 1, a part of the main plate 1 is shown in a broken state.

  First, the configuration of this embodiment will be described. The base plate 1 and the cover plate 2 of the present embodiment have a substantially circular outer shape of the same size, are attached to each other by means not shown, and constitute a blade chamber between the two. The base plate 1 is made of synthetic resin, and has a large concave portion 1a centered on the optical axis on a surface opposite to the surface on the blade chamber side (hereinafter referred to as a surface outside the blade chamber). In addition, a circular opening 1b centered on the optical axis is formed.

  Further, an annular recess 1c having a slightly smaller outer diameter than the recess 1a is formed on the surface of the blade chamber that is back to back with the recess 1a, and the space between the bottom surfaces of the two recesses 1a and 1c is thin. Is formed. In FIG. 1, a part of the thin annular portion is shown broken. In the thin annular portion, six blade mounting holes 1d are formed as through-holes at substantially equal angular intervals centered on the optical axis. In FIG. 1, four of them are shown. And only one sign is attached.

  On the other hand, the cover plate 2 is also formed with a circular opening 2a centered on the optical axis, but in the case of the present embodiment, the opening 1b is far more than the opening 2a. Big. Therefore, in the present embodiment, the opening 2a of the cover plate 2 regulates the maximum optical path of the subject light, that is, the size and shape of the maximum aperture opening.

  In this embodiment, a large recess 1a is formed on the surface of the base plate 1 outside the blade chamber, and the opening 1b is made larger than the opening 2a. This is shown by a two-dot chain line in FIG. In addition, a part of the lens barrel 3 can be arranged close to the blade chamber. Therefore, if this is not necessary, the sizes of the opening 1b and the opening 2a may be reversed, and the maximum diaphragm opening may be regulated by the opening 1b, or the inner diameter of the diaphragm drive ring 6 described later may be regulated. The size and the diameter of the opening 2a may be reversed so that the inner diameter of the diaphragm drive ring 6 regulates the maximum diaphragm opening.

  In the present embodiment, the opening 1b is also circular, but the opening 2a regulates the maximum aperture opening, so that the blade attachment hole 1d can be formed in the annular thin portion. As long as it is possible, the opening 1b does not have to be circular. In the case of the present embodiment, the annular thin portion is formed only by forming the blade attachment hole 1d, so that the portion is considerably thin. The barrel 3 can be arranged close to each other, which is advantageous for making the camera thinner and more compact.

  Next, the shape on the blade chamber side of the main plate 1 will be described. Although the annular recess 1c as described above is formed on the surface of the base plate 1 on the blade chamber side, as shown in FIG. 2, it is adjacent to the recess 1c and deeper than the recess 1c. A gear housing 1e is formed, and a shaft 1f is provided upright on the bottom surface. A rotor accommodating portion 1g is formed adjacent to the gear accommodating portion 1e. The rotor accommodating portion 1g is cup-shaped and protrudes from the surface of the main plate 1 outside the blade chamber. Is formed. A shaft 1h is erected on the bottom surface of the rotor accommodating portion 1g, and it is also known that a metal shaft member is erected by caulking or the like instead of the shaft portion 1h. .

  Then, next, the structure of the member arrange | positioned at the blade chamber side is demonstrated. First, the rotor 4 of the stepping motor is rotatably attached to the shaft 1h in the rotor housing portion 1g. The rotor 4 is a well-known rotor of a stepping motor, and a gear portion 4b is formed on one end side of a hollow shaft portion 4a made of synthetic resin, and a circumferential surface has four poles on the other end side. The permanent magnet 4c magnetized in this way is integrally formed, and the hollow portion of the shaft portion 4a is fitted to the shaft 1h. Further, a parent gear (two-stage gear) 5 is rotatably attached to the shaft 1 f standing on the gear housing 1 e, and the parent gear 5 a is connected to the gear 4 b of the rotor 4. Meshed.

  A diaphragm drive ring 6 is rotatably disposed in the annular recess 1c. As shown in FIG. 1, the diaphragm drive ring 6 is composed of six cam grooves 6a having the same shape with the optical axis as the center and having substantially equal angular intervals (only one is labeled). Is formed). Further, six relief portions 6b (only one is labeled) are formed on the outer peripheral edge side of the cam groove 6a so as to have substantially equal angular intervals. Further, a partial gear portion 6c composed of a plurality of tooth portions is formed on the outer peripheral edge over a predetermined angular range, and meshes with the child gear 5b of the parent gear 5 described above. In this embodiment, the escape portion 6b is formed as an arc-shaped hole, but it may be formed by cutting a narrow region on the outer peripheral edge side.

  Six diaphragm blades 7 having exactly the same shape are arranged in the blade chamber. In FIG. 1, only one of them is labeled. Each of the diaphragm blades 7 has a blade shaft 7a and a connecting pin 7b on the same surface, and the blade shaft 7a is inserted into the escape portion 6b of the diaphragm drive ring 6 so that the blade mounting of the main plate 1 is performed. The connecting pin 7 b is inserted into the cam groove 6 a of the aperture drive ring 6 by being rotatably fitted in the hole 1 d. In this embodiment, six diaphragm blades are provided. However, the present invention may be any number of three or more blades. In such a case, the blade mounting hole 1d, the cam groove 6a, The number of escape portions 6b is also the same.

  Finally, the structure of the stator of the stepping motor attached to the surface outside the blade chamber of the main plate 1 will be described. The structure is substantially the same as that described in Patent Document 1. The stator according to this embodiment includes yokes 8 and 9, hollow bobbins 10 and 11, and coils 12 and 13 wound around the bobbins 10 and 11. Among them, the yokes 8 and 9 are substantially U-shaped with two leg portions and a base portion connecting one end thereof, and are attached to the base plate 1 by an appropriate means. , 11 are passed through the hollow portions. The yokes 8 and 9 have magnetic poles at the tips of their two legs, and are inserted into four holes formed in the rotor housing portion 1g, so that the permanent magnet 4c provided on the rotor 4 Although facing the circumferential surface, in FIG. 2, the tip of the leg portion penetrating the hollow portion of the bobbins 10 and 11 is inserted into two holes 1i and 1j out of the above four holes. The inserted state is shown.

  Next, the operation of this embodiment will be briefly described with reference to FIG. FIG. 1 shows a control state of the intermediate aperture opening by the cooperation of the six aperture blades 7. In the state before the start of photographing, normally, the aperture blade 7 is normally in a state in which the opening 2a is fully opened, that is, in a control state of the maximum aperture opening. For this reason, the state shown in FIG. 1 is a state where the camera is operated and stopped until this state is reached in photographing.

  When photographing is finished in this state, the rotor 4 is rotated clockwise by pulse energization of the coils 12 and 13, and the diaphragm drive ring 6 is rotated clockwise via the parent-child gear 5. Therefore, each of the six diaphragm blades 7 pushes the connecting pin 7b into the cam groove 6a of the diaphragm drive ring 6 and simultaneously rotates counterclockwise to enlarge the diaphragm aperture. Immediately after the opening 2a is fully opened, the pulse energization to the coils 12 and 13 is terminated, the operation of the aperture blade 7 is stopped, and the next photographing standby state is entered.

  When the next shooting is performed with an aperture other than the maximum aperture, predetermined pulse energization is performed on the coils 12 and 13. Thereby, the rotor 4 rotates counterclockwise, and the diaphragm drive ring 6 is rotated counterclockwise via the parent gear 5. For this reason, the six diaphragm blades 7 are pushed in the respective cam grooves 6a of the diaphragm drive ring 6 by the connecting pins 7b and simultaneously rotated in the clockwise direction, thereby reducing the aperture opening. Thereafter, when the predetermined pulse energization is completed, the control is stopped in the control state of the corresponding aperture opening, and photographing is performed. Then, when shooting is completed, as described above, the shooting standby state, which is the maximum aperture opening control state, is restored.

  The description of the operation has been made on the assumption that the aperture device of the present embodiment is employed in a still camera, but the aperture device of the present embodiment can also be employed in a movie camera. In that case, the rotor 4 is rotated from the standby state after being rotated from the shooting standby state, and is rotated counterclockwise or clockwise according to the change of the subject light during shooting. To change the size of the aperture. In this embodiment, a stepping motor is used as the driving means. However, for example, a known current control type motor incorporating a Hall element may be used.

  As described above, when configured as in the present embodiment, as in the configuration described in Patent Document 2, the assembly work is easier than the configuration described in Patent Document 1. In addition, the diaphragm blade 7 of the present embodiment is attached to the region of the base plate 1 facing the diaphragm drive ring 6, and can be shorter (smaller) than the diaphragm blade described in Patent Document 2, A small driving force is required.

  Further, in this embodiment, it is not necessary to use too much nerve at the position where the diaphragm blade is attached, and the degree of freedom in design is large. In other words, the second diaphragm blade 7 in the clockwise direction from the diaphragm blade 7 that is labeled in FIG. 1 is positioned more radially than the diaphragm drive ring 6 as viewed from the optical axis, as in the configuration of Patent Document 2. If it is going to be attached to the main plate 1, it cannot be attached because of the parent-child gear 5, but in the configuration of this embodiment, there is no need to consider such a thing.

  Further, in the configuration of Patent Document 2, in order to avoid such a situation, if the six diaphragm blades 7 are attached in a position rotated in the clockwise direction as a whole, they are attached even if the parent-gear gear 5 is present. Is possible. However, when configured in this way, when the first diaphragm blade 7 is rotated counterclockwise from the diaphragm blade 7 indicated by the reference numeral in FIG. 1, the opening 2a is fully opened. Before that, there is a risk of interference with the parent-child gear 5. This becomes more problematic as the maximum aperture is increased in design, and the more the number of aperture blades is increased in order to make the aperture aperture closer to a circular shape. However, in the configuration of the present embodiment, it is almost unnecessary to consider such a situation, so that the design becomes easier than the configuration of Patent Document 2.

  Further, in the case of this embodiment, the six diaphragm blades 7 are operated within the outer diameter of the diaphragm drive ring 6. Therefore, most of the annular region of the base plate 1 in the radial direction is unnecessary, except for the stepping motor attachment region and the camera attachment region. Therefore, in the state in which the unnecessary region is not formed, that is, in the state of the diaphragm device alone, as can be seen from the configuration of Patent Document 2, the method of attaching the diaphragm blades to the main plate is different. This is much smaller.

  By the way, the reason why this embodiment forms the unnecessary area is that it is conscious of unitization with the shutter device. That is, in the case of such a configuration, in FIG. 2, another plate member is attached to the lower side of the cover plate 2, and the blade chamber of the shutter blade is formed between the cover plate 2 and the cover plate 2. And the area | region which attaches the motor which operates a shutter blade | wing on the surface which attaches the stator of the stepping motor of the base plate 1 is needed. Furthermore, it is difficult to operate the shutter blade only in the region within the outer diameter of the aperture driving ring 6. For this reason, the ground plate 1 of the present embodiment also has a region that is unnecessary as described above. However, even if there is such a reason, there is no need for an unnecessary region. Considering the case of eliminating the area, the configuration of the present embodiment is more advantageous for downsizing than the configuration of Patent Document 2.

It is the top view of the Example which showed the control state of intermediate | middle aperture opening. It is sectional drawing for demonstrating the overlapping state of the member which comprises the Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground plate 1a, 1c Recessed part 1b, 2a Opening 1d Blade attachment hole 1e Gear accommodation part 1f, 1h Shaft 1g Rotor accommodation part 1i, 1j Hole 2 Cover plate 3 Lens barrel 4 Rotor 4a Shaft part 4b Gear part 4c Permanent Magnet 5 Master gear 5a Master gear 5b Slave gear 6 Aperture drive ring 6a Cam groove 6b Escape portion 6c Partial gear portion 7 Aperture blade 7a Blade shaft 7b Connecting pin 8, 9 Yoke 10, 11 Bobbin 12, 13 Coil

Claims (2)

  A blade chamber is formed between the cover plate and an annular recess centered on the optical axis on the surface of the blade chamber, and a plurality of blade mounting holes are provided at substantially equal angular intervals around the optical axis in the recess. A diaphragm driving ring having the same number of cam grooves and a plurality of relief portions at the same angular intervals as the blade mounting holes and rotatably disposed in the recess. , Disposed between the diaphragm drive ring and the cover plate, and having a blade shaft and a connecting pin on the same surface, the blade shaft being inserted into the relief portion and then being rotatable in the blade mounting hole A plurality of diaphragm blades that are fitted and the connecting pin is inserted into the cam groove, and a plurality of diaphragm blades that are attached to the main plate and reciprocally rotate the diaphragm drive ring in the same direction at the same time The size of the aperture opening by rotating and cooperating with them Camera diaphragm device, characterized in that and a driving means for changing the.   A gear is rotatably attached to the base plate between the cover plate and a partial gear portion meshing with the gear is formed on an outer peripheral portion of the aperture driving ring, and the driving means is the gear. 2. The aperture device for a camera according to claim 1, which is a stepping motor that reciprocally rotates the camera.

Images