JP2008008947A - Blade drive device for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve the reduction of cost while maintaining compact and thin constitution, in a blade drive device for a camera constituted so that a plurality of electromagnetic actuators can drive individual blades. <P>SOLUTION: A frame member 7 made of synthetic resin, where coils 8 and 9 are wound round two bobbin parts 7a and 7b integrally molded, is attached to mounting shafts 1m, 1n, 1p and 1q erected on a bottom board 1 made of synthetic resin by thermal caulking. Two rotors 5 and 6 are rotatably attached to two rotary shafts 1r and 1s formed on the bottom board 1. Two yokes 10 and 11 are attached to the mounting shafts 1q and 1p together with the frame member 7 by fitting their one-sided leg parts 10a and 11a in the hollow parts of the bobbin parts 7a and 7b. A drive pin 5c integrated with the rotator 5 is coupled to a shutter blade 4 in a blade chamber, and a drive pin 6c integrated with the rotor 6 is coupled to a diaphragm blade 3 in the blade chamber. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a camera blade drive device in which blade members such as shutter blades, aperture blades, and filter blades are reciprocated in a blade chamber.

  Among camera blade driving devices, the shutter device, the diaphragm device, and the filter device are not individually unitized, but two or more of them may be configured as one unit. . In that case, the blades of each device may be disposed in one blade chamber, or may be disposed in individual blade chambers. Recently, it has become common for the blades of each device to reciprocate with their respective electromagnetic actuators. Therefore, when two or more devices are configured as one unit, two or more electromagnetic actuators are provided.

  Even when each of the above devices is unitized, there may be two or more electromagnetic actuators. For example, in some shutter devices, during exposure operation, a shutter blade that performs only an opening operation and a shutter blade that performs only a closing operation are operated by separate electromagnetic actuators. In the case of an aperture device, there are a plurality of aperture blades having aperture openings of different diameters, which are selectively advanced and retracted to an exposure opening. In some cases, a plurality of filter blades having ND filter sheets with different areas or different concentrations are provided, and they are selectively advanced and retracted to the opening for exposure. Also in this case, there are some equipped with a plurality of electromagnetic actuators in order to individually actuate each blade. As described above, the present invention relates to a camera blade drive device that includes a plurality of electromagnetic actuators and that individually reciprocates different blades.

  By the way, such a blade drive device for a camera has recently been incorporated in a camera for an information terminal device such as a personal computer or a mobile phone in addition to a small digital camera. As a result, there has been a strong demand for reduction in thickness. Therefore, in the case of a camera blade drive device provided with a plurality of electromagnetic actuators as described above, there is a problem of how to reduce the thickness of the electromagnetic actuator, but a camera that can meet such demands. An example of the blade driving device for use is described in Patent Document 1 below.

JP 2005-156616 A

  In the case of the camera blade drive device described in Patent Document 1, two yokes are used on one electromagnetic actuator in a stacked manner. This is for obtaining a shape necessary for performing a role other than the original yoke by a part of the yoke. In this case, since the yoke is a metal part, it is 2 rather than a single part. This is because processing as a part is considered advantageous in terms of cost. Therefore, it is not necessary to perform such other functions, and even when the yoke is made as one part, the thickness of two sheets in the case where two sheets are stacked in this way is required. Considering this, when looking at the camera blade driving device described in Patent Document 1, it must be said that it is extremely difficult to achieve further thinning in terms of structure. Absent. Therefore, what is required next in this type of blade driving device for a camera is how to reduce the cost while maintaining such a small and thin configuration. .

  The present invention has been made to solve such problems, and an object of the present invention is to arrange a rotor having a permanent magnet so as to be rotatable between a main plate and a frame member. And a yoke having two legs is fitted to a bobbin part provided on the frame member so that one leg is opposed to the circumferential surface of the rotor with the tips of both legs as magnetic poles. A plurality of electromagnetic actuators configured as described above, wherein the electromagnetic actuators reciprocate different types of blades, and the frame member is replaced with a plurality of electromagnetic actuators. By providing a common member, it is an object to provide a blade driving device for a camera that enables cost reduction while maintaining a reduced size and thickness.

  In order to achieve the above object, a camera blade driving device of the present invention has a ground plate having an opening for exposure and a plurality of hollow bobbin portions around which coils are wound, and is attached to the ground plate. And a plurality of rotors each having a permanent magnet and rotatably attached to at least one of them between the main plate and the frame member, each having two legs. One of those legs is fitted to each bobbin, and the tip of both legs is opposed to the circumferential surface of each rotor as a magnetic pole, and the rotation is performed by energizing each coil. A plurality of yokes that individually reciprocate the rotor, and a plurality of blade driving means that are individually connected to different blades and that rotate the blades by reciprocating rotation of the rotors to advance and retract the openings. Be prepared.

  In that case, the frame member is formed in a substantially U-shape so as to surround the opening portion by two substantially parallel portions and a portion connecting them, and in the substantially parallel two portions, When the bobbin portion is formed one by one, and the two rotors are arranged between the connecting portion and the ground plane, it becomes an extremely compact configuration suitable for miniaturization, In addition, it is more preferable that the tip portions of the two substantially parallel portions are each attached to the main plate together with the yoke. Further, the camera blade driving device of the present invention is a driving pin in which each driving means is integrated with each rotor and reciprocates within a predetermined angular range together with each rotor. If it is inserted into the blade chamber from the hole formed in the base plate and is connected to the blades in the blade chamber, the structure becomes more advantageous in terms of cost. Further, one of the driving means may be connected to two blades rotating in opposite directions at the same time.

  In the present invention, a rotor having a permanent magnet is rotatably arranged between a main plate and a frame member, and a yoke having two legs is used with one leg as a frame member. It is equipped with a plurality of electromagnetic actuators that are fitted to the provided bobbin part and configured to oppose the circumferential surface of the rotor with the tip ends of both legs as magnetic pole parts. In the camera blade drive device in which the blades of the camera are reciprocated, the frame member is not only reduced in number of parts by being a single member common to a plurality of electromagnetic actuators, but also the coil winding around the frame member. Since the number of man-hours required for assembly of the frame member with respect to the turn and the base plate can be reduced, the apparatus can be reduced in size and thickness, and the cost can be reduced.

  Embodiments of the present invention will be described with reference to the illustrated examples. As described above, the camera blade driving device of the present invention can be applied to a single shutter device, diaphragm device, and filter device, and two or more of the shutter device, diaphragm device, and filter device are combined into one. The present invention can also be applied to an apparatus configured as a unit. In addition, these devices can be employed in cameras using silver halide films, and can also be employed in digital cameras including various information terminal equipment cameras and video cameras. However, since it is not necessary to individually describe all of these cases with specific examples, an embodiment in which the shutter device and the aperture device are configured as one unit will be described.

  This embodiment is a camera blade driving device in which a shutter device having one shutter blade and an aperture device having one diaphragm blade are configured as one unit. The camera blade driving device can be used in a silver salt film camera, but in the case of this embodiment, it will be described on the assumption that it is used in a digital camera. FIG. 1 is a plan view of the embodiment, and shows a photographing standby state in which the opening for exposure is fully opened, and FIG. 2 is in an unfolded state so that it can be seen at a glance. FIG. 3 is an exploded perspective view of the embodiment before assembly. 4 to 6 are plan views of the embodiment shown in the same manner as FIG. 1, and FIG. 4 shows a state immediately after the end of photographing with the shutter blades closed in FIG. FIG. 5 shows a state in which the diaphragm blades are exposed to the opening for exposure in FIG. 1, and FIG. 6 shows a state immediately after the photographing with the shutter blades in the closed state in FIG. It is a thing.

  First, the configuration of the present embodiment will be described mainly with reference to FIGS. The base plate 1 of the present embodiment is made of synthetic resin and is relatively thick, and constitutes a blade chamber between the cover plate 2 and the base plate 1. The base plate 1 is formed with a circular opening 1a for exposure and two long holes 1b and 1c having an arc shape. Further, the cover plate 2 is also formed with a circular exposure opening 2a opposite to the opening 1a. The exposure opening of the present embodiment has a larger diameter than the opening 1a. Is regulated by the opening 1a. Further, the cover plate 2 is also formed with long holes 2b and 2c having substantially the same arc shape at positions facing the long holes 1b and 1c.

  On the surface of the main plate 1 on the blade chamber side, four mounting shafts are erected integrally at four corners, but only two mounting shafts 1d and 1e are shown in FIG. These four mounting shafts are cylindrical before the cover plate 2 is attached, and after passing through the four holes 2d, 2e, 2f, 2g formed at the four corners of the cover plate 2. The cover plate 2 is attached by thermally melting the tip of the tip and deforming it into a bowl shape. In addition, two blade shafts 1f, 1g and four stopper shafts 1h, 1i, 1j, 1k are provided upright on the surface of the base plate 1 on the blade chamber side. 2h, 2i, 2j, 2k, 2m, 2n.

  In the blade chamber, the diaphragm blade 3 and the shutter blade 4 are arranged with the diaphragm blade 3 on the base plate 1 side. The aperture blade 3 has a hole 3a, a long hole 3b, and an aperture portion 3c having a diameter smaller than that of the aperture portion 1a. The aperture 3a rotates about the blade shaft 1g. It is possible to fit. The shutter blade 4 has a hole 4a and a long hole 4b, and the hole 4a is rotatably fitted to the blade shaft 1f. In this embodiment, the diaphragm blades 3 and the shutter blades 4 are arranged in the same blade chamber. As is well known, the base plate 1 and the cover plate 2 are separated by an intermediate plate. Two blade chambers may be configured and arranged in separate blade chambers.

  On the other hand, outside the blade chamber of the main plate 1, four mounting shafts 1m, 1n, 1p, 1q and two rotating shafts 1r, 1s are erected by integral molding. Of these, the rotors 5 and 6 are rotatably attached to the rotary shafts 1r and 1s. Each of these rotors 5 and 6 is formed integrally with cylindrical permanent magnets 5a and 6a magnetized in two poles in the radial direction, and the permanent magnets 5a and 6a, and projects in the radial direction. It consists of synthetic resin arms 5b and 6b and drive pins 5c and 6c provided at the ends of the arms 5b and 6b. One drive pin 5c is inserted into the blade chamber from the long hole 1b of the base plate 1, is fitted into the long hole 4b of the shutter blade 4, and its tip protrudes from the long hole 2b of the cover plate 2 to the outside of the blade chamber. The other drive pin 6c is inserted into the blade chamber through the long hole 1c of the base plate 1, is fitted into the long hole 3b of the aperture blade 3, and the tip of the drive pin 6c extends from the long hole 2c of the cover plate 2 to the outside of the blade chamber. It sticks out.

  Further, a frame member 7 made of synthetic resin is attached to the four attachment shafts 1m, 1n, 1p, and 1q that are erected integrally with the base plate 1. The frame member 7 is formed in a U shape by two substantially parallel portions and a portion connecting one end thereof, and is disposed so as to surround the opening 1a. And hollow bobbin part 7a, 7b (refer FIG. 2) is formed in those two substantially parallel site | parts, and the coils 8 and 9 are wound there. The frame member 7 has four holes 7c, 7d, 7e, and 7f, and the rotors 5 and 6 are connected to the rotation shafts 1r and 1s by a portion that connects the two substantially parallel portions. I try to prevent it from coming off.

  In this embodiment, the rotary shafts 1r and 1s are erected only on the base plate 1, but at least one of them may be erected on the frame member 7. There is no problem even if it stands short on both sides. Further, the rotors 5 and 6 of the present embodiment are made of permanent magnets and synthetic resin as described above, but the entire structure including the arms 5b and 6b and the drive pins 5c and 6c is made of permanent magnets. It does not matter.

  The yoke 10 of this embodiment has two leg portions 10a and 10b and a hole 10c, and one leg portion 10a is fitted in the hollow portion of the bobbin portion 7a. And the front-end | tip part of both the leg parts 10a and 10b is made into the magnetic pole part, and the permanent magnet 5a of the rotor 5 is made to oppose the peripheral surface in between. The other yoke 11 has two leg portions 11a and 11b and a hole 11c, and one leg portion 11a is fitted into the hollow portion of the bobbin portion 7b. And the front-end | tip part of both the leg parts 11a and 11b is made into the magnetic pole part, and the permanent magnet 6a of the rotor 6 is made to oppose the peripheral surface in between.

  The frame member 7 in which the leg portions 10a and 11a of the yokes 10 and 11 are fitted to the bobbin portions 7a and 7b, after the holes 7c and 7d are fitted to the mounting shafts 1m and 1n of the base plate 1, respectively. In addition, after the holes 7e and 7f are fitted to the mounting shafts 1p and 1q of the main plate 1 together with the holes 11c and 10c of the yokes 11 and 10, the four mounting shafts 1m, 1n, 1q and 1p It is attached to the main plate 1 by thermally melting the tip and deforming it into a large bowl shape. In this embodiment, since the two bobbin portions 7a and 7b are provided on the single frame member 7 as described above, the bobbin portion is integrated as in the camera blade driving device described in Patent Document 1. Compared to the two frame members formed one by one, not only the number of parts is small, but also the number of winding steps of the two coils 8 and 9 and the number of assembly steps to the main plate 1 can be reduced. Cost reduction is possible.

  Next, the operation of this embodiment will be described with reference to FIGS. 1 and 4 to 6. FIG. 1 shows a photographing standby state. The aperture blade 3 and the shutter blade 4 fully open the opening 1a that regulates the exposure opening. For this reason, a solid-state image sensor (not shown) is exposed to subject light, and the photographer can observe the subject image on the monitor. At this time, the coils 8 and 9 are not energized. However, as is well known, at this time, one of the rotors 5 is rotated clockwise by the magnetic force due to the opposing arrangement relationship between the magnetic poles of the permanent magnet 5a and the two magnetic pole portions of the yoke 10, and is driven by the drive pin 5c. Since the shutter blade 4 is biased to rotate in the clockwise direction, the shutter blade 4 is pressed against the stopper shaft 1h, and this state is reliably maintained. Similarly, the other rotor 6 is rotated counterclockwise by the magnetic force due to the opposing arrangement relationship between the magnetic poles of the permanent magnet 6a and the two magnetic pole portions of the yoke 11, and the diaphragm blades are driven by the drive pins 6c. Since the blade 3 is biased to rotate counterclockwise, the diaphragm blade 3 is pressed against the stopper shaft 1i.

  When the release button is pressed at the time of shooting, it is determined based on the measurement result by a photometry circuit (not shown) whether to shoot with the subject light reduced or not. First, a case where it is determined that shooting is performed without reducing subject light will be described. In that case, immediately after the electric charge accumulated in the solid-state image sensor is released, photographing is started, and new electric charges are accumulated in the solid-state image sensor. When a predetermined time elapses, a forward current is supplied to the coil 8 by a signal from the exposure time control circuit. As a result, the rotor 5 is rotated counterclockwise, and the shutter blade 4 is rotated counterclockwise by the drive pin 5c to close the opening 1a. FIG. 4 shows a state in which the shutter blade 4 comes into contact with the stopper shaft 1j and stops immediately after the opening 1a is completely closed.

  In such a state shown in FIG. 4, the charge accumulated in the solid-state image sensor is transferred to the storage device as imaging information. When the transfer ends, a current in the reverse direction is supplied to the coil 8 unlike the above. Thereby, the rotor 5 is rotated in the clockwise direction, and the shutter blade 4 is rotated in the clockwise direction by the drive pin 5c to open the opening 1a. The shutter blade 4 comes into contact with the stopper shaft 1h and stops immediately after the opening 1a is fully opened. Thereafter, when the coil 8 is deenergized, the imaging standby state shown in FIG. 1 is restored.

  Next, a description will be given of a case where, when the release button is pressed during shooting, it is determined that shooting is performed with subject light reduced based on a measurement result by a photometry circuit (not shown). In that case, a forward current is first supplied to the coil 9. Therefore, the rotor 6 is rotated in the clockwise direction, and the diaphragm blade 3 is rotated in the clockwise direction by the drive pin 6c, so that the aperture 3c having a small diameter for aperture opening enters the opening 1a. To go. When the opening 3c reaches a position substantially concentric with the opening 1a, the diaphragm blade 3 comes into contact with the stopper shaft 1k and stops. FIG. 5 shows the state at that time. At this time, the current may be continuously supplied to the coil 9, but even if the current supply is cut off, the rotor 6 has the magnetic poles of the permanent magnet 6 a and the two magnetic pole portions of the yoke 11. The diaphragm blade 3 is biased so as to rotate in the clockwise direction by the magnetic force due to the opposing arrangement relationship, and the diaphragm blade 3 can be kept pressed against the stopper shaft 1k.

  In this way, when the state shown in FIG. 5 is reached, the charge accumulated in the solid-state imaging device as described above is released, and photographing is started. When a predetermined time elapses, a forward current is supplied to the coil 8 by a signal from the exposure time control circuit, so that the shutter blade 4 is rotated counterclockwise as described above. Then, the opening 1a is closed. FIG. 6 shows a state in which the shutter blade 4 comes into contact with the stopper shaft 1j and stops immediately after the opening 1a is completely closed.

  In the state shown in FIG. 6, when the imaging information is transferred to the storage device, a current in the reverse direction is supplied to the coil 8 as described above. Directional current is supplied. Therefore, the shutter blade 4 opens the opening 1a as described above. On the other hand, since the rotor 6 is rotated counterclockwise, the aperture blade 3 is rotated counterclockwise by the drive pin 6c. It is rotated and retreats from the opening 1a. Then, the diaphragm blade 3 completely retracts from the opening 1a before and after the shutter blade 4 fully opens the opening 1a, and immediately after that, the shutter blade 4 comes into contact with the stopper shaft 1h and stops. The diaphragm blade 3 comes into contact with the stopper shaft 1i and stops. Thereafter, when the energization of the coils 8 and 9 is cut off, the imaging standby state shown in FIG. 1 is restored.

  The camera blade driving device of the present embodiment is configured with the shutter device and the diaphragm device as one unit. However, if the opening 3c of the diaphragm blade 3 is covered with an ND filter sheet, The diaphragm blade 3 becomes a filter blade, and the shutter device and the filter device are configured as one unit. If the shutter blade 4 is made of an ND filter sheet, the shutter blade 4 becomes a filter blade, The filter device and the diaphragm device are configured as one unit. If the shutter blade 4 is formed with an opening smaller than the opening 1a and having a diameter different from that of the opening 3c, the shutter blade 4 becomes the diaphragm blade, and the two diaphragm devices are combined into one unit. If two openings for two diaphragms are covered with an ND filter sheet, the two diaphragm blades become filter blades, and the two filter devices are combined into one unit. It becomes what was configured as. Further, when the shutter blades 3 are not formed in the aperture blades 3 of this embodiment and the shutter blades are used, as described in JP-A-2003-186079, one shutter blade is opened during photographing. It is also possible to configure as a shutter device that is dedicated and the other shutter blade is closed. These configurations are all embodiments of the present invention.

  In the present embodiment, the two bobbin portions 7a and 7b are formed on the frame member 7, but the present invention is not limited to such a configuration, and the bobbin portion surrounds the opening 1a. Three or more may be formed in series. In such a configuration, since it is provided with three or more electromagnetic actuators, for example, a camera blade drive device in which a shutter device, a diaphragm device, and a filter device are configured as one unit is also provided. Will be obtained.

It is a top view of an Example, Comprising: The imaging | photography standby state which made the opening part for exposure fully opened is shown. It is principal part sectional drawing of an Example. It is a disassembled perspective view of the Example before an assembly. FIG. 2 is a plan view of the embodiment, and shows a state immediately after the end of photographing with the shutter blades in a closed state in FIG. 1. FIG. 2 is a plan view of the embodiment, showing a state in which the diaphragm blades face the opening for exposure in FIG. 1. FIG. 6 is a plan view of the embodiment, and shows a state immediately after the end of photographing with the shutter blades closed in FIG. 5.

Explanation of symbols

1 Ground plate 1a, 2a, 3c Opening 1b, 1c, 2b, 2c, 3b, 4b Long hole 1d, 1e, 1m, 1n, 1p, 1q Mounting shaft 1f, 1g Blade shaft 1h, 1i, 1j, 1k Stopper shaft 1r , 1s Rotating shaft 2 Cover plate 2d-2k, 2m, 2n, 3a, 4a, 7c-7f, 10c, 11c Hole 3 Aperture blade 4 Shutter blade 5, 6 Rotor 5a, 6a Permanent magnet 5b, 6b Arm 5c, 6c Drive pin 7 Frame member 7a, 7b Bobbin portion 8, 9 Coil 10, 11 Yoke 10a, 10b, 11a, 11b Leg portion

Claims (5)

  A ground plate having an opening for exposure; a frame member having a plurality of hollow bobbin portions around which coils are wound and attached to the ground plate; each having a permanent magnet, and the ground plate and A plurality of rotors rotatably attached to at least one of them between the frame member and each of the two leg portions, and one of the leg portions is fitted to each of the bobbin portions; The front ends of both legs are opposed to the circumferential surface of each rotor as magnetic poles, and a plurality of yokes that individually reciprocate the rotor by energizing each coil, and each of the different blades individually A blade driving device for a camera, comprising: a plurality of blade driving means that are connected to rotate the blades by reciprocating rotation of the rotors to advance and retract the opening.   The frame member is formed in a substantially U shape so as to surround the opening by two substantially parallel portions and a portion connecting them, and the bobbin portion is formed in the two substantially parallel portions. The camera blade driving device according to claim 1, wherein two rotors are disposed between the connecting portions and the ground plane.   3. The blade driving device for a camera according to claim 2, wherein the tip portions of the two substantially parallel portions are each attached to the main plate together with the yoke.   Each of the driving means is a driving pin that is integrated with each of the rotors and reciprocates within a predetermined angle range together with each of the rotors. The driving pin is inserted into a blade chamber from a hole formed in the base plate. 4. The camera blade drive device according to claim 1, wherein the camera blade drive device is connected to each blade in the blade chamber.   5. The camera blade driving device according to claim 1, wherein one of the driving means is connected to two blades rotating in opposite directions at the same time.

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