JP2005241874A - Blade driving device for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blade driving device for a camera that realizes in reduction in cost and an area for fitting two motors each operating at least one blade to a bottom plate. <P>SOLUTION: The two rotors 4 and 5 are rotatably fitted to shafts 1d and 1e of a main bottom plate 1 in a motor chamber constituted between the main bottom plate 1 and a motor frame 11, and their output pins 4a and 5a are inserted into two blade chambers. The output pin 4a is coupled with shutter blades 15 and 16 in one blade chamber and the output pin 5a is coupled with an aperture blade 17 in the other blade chamber. Further, a yoke 6 is arranged between their rotors 4a and 5a and while magnetic pole parts of two leg parts 6c and 6d face the peripheral surface of the rotor 4a, magnetic pole parts of other two leg parts 6e and 6f face the peripheral surface of the rotor 5, the leg parts 6c and 6e being wound with coils 7 and 8. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a camera blade driving device in which shutter blades, diaphragm blades, and the like are driven by a motor.

  Some recent camera shutter devices are known in which two shutter blades are simultaneously reciprocated in opposite directions to open and close an opening for a photographing optical path. The shutter device having the configuration is employed for both a silver salt film camera and a digital camera (a camera using a solid-state imaging device such as a digital still camera, a digital video camera, and a camera for various information terminal devices). Further, recently, as a built-in digital camera, attention has been paid to one that opens and closes a photographing optical path opening by reciprocatingly rotating a single shutter blade.

  In addition, in a diaphragm device for a camera, two diaphragm blades are arranged in a blade chamber formed between a main ground plate and an auxiliary ground plate, and simultaneously actuated linearly in opposite directions to obtain a predetermined diaphragm. Although it is also known that it is stopped at the aperture restriction position, in the case of a miniaturized popular camera, a single aperture blade having a small circular aperture opening is used as an aperture for an imaging optical path. In many cases, photographing with a small aperture is performed when the camera enters the camera, and photographing with a large aperture is performed when the retracted state is established. And the aperture device of those structures is employ | adopted for the silver salt film camera and the digital camera.

  In addition, an ND filter device is known as a device that reduces the amount of photographing light like the diaphragm device. A recent ND filter device has a blade having a circular opening such as the above-described diaphragm blade (the opening in this case may be approximately the same size as the opening for the photographing optical path). In general, a member in which an ND filter plate is attached so as to cover its opening is used as a filter blade, and the member is operated in the same manner as the above-described diaphragm blade. However, in addition to this, the ND filter plate is simply made into a blade shape to make a filter blade, or such a blade-shaped ND filter plate is sandwiched by two blade members having a circular opening, and three layers are stacked. A filter blade having a configuration is also known. And the filter apparatus of such a structure can be employ | adopted for a silver salt film camera and a digital camera.

  Further, in each of the above devices, a current control type motor called a moving magnet type motor or the like is often used as a drive source because it is easy to reduce the size at a low cost. In this type of motor, the rotor has a cylindrical or columnar permanent magnet portion magnetized in two or four poles in the radial direction, and an output pin (drive pin and Is also connected to the blades in the blade chamber, and is configured to rotate in a predetermined rotation angle range in a direction corresponding to the energization direction to the stator coil. The output pin is also known to be formed of a synthetic resin material mixed with magnetic particles by simultaneous molding with the cylindrical permanent magnet part. In many cases, the permanent magnet portion is molded in advance and is molded together with the rotating shaft by so-called outsert processing using a synthetic resin material. In addition to these, an output pin that is manufactured as a separate member in advance and integrated with a permanent magnet portion is also known.

  This type of motor is usually attached to the surface of the main base plate outside the blade chamber, but the overall configuration varies depending on the configuration of the stator. Among them, what has been most frequently implemented so far is one in which a coil is wound around two stator frames bearing a rotor so as to surround those bearing portions. However, recently, the basic configuration itself is well known, and a configuration called a flat type or the like has begun to attract attention. In this type of motor, a substantially U-shaped yoke around which a coil is wound is arranged with its two magnetic pole portions opposed to the peripheral surface of the rotor. An example of a motor is described in Patent Document 1.

  In addition, the shutter device, the diaphragm device, and the filter device that use this type of moving magnet type motor as a drive source may be manufactured as one unit, but other devices such as a shutter device and a diaphragm device may be used. It may be manufactured as a unit with the above devices. In the case of the shutter device, as described in Patent Document 1, an opening shutter blade and a closing shutter blade may be individually operated by respective motors. In the case of a diaphragm device, two diaphragm devices are manufactured as a single unit so that two diaphragm blades having different circular aperture openings can be individually operated by respective motors. There are things to do.

  Furthermore, in the case of a filter device, two filter blades with different sizes of openings covered with the ND filter plate are individually operated by respective motors, or the sizes of the openings are the same but cover them. In order to individually operate two filter blades having different ND filter plate concentrations by respective motors, two filter devices may be manufactured as one unit. And when manufacturing two devices as one unit, in order to prevent the blades from colliding with each other during operation, the main ground plate and the auxiliary ground plate are partitioned by an intermediate plate (also called a partition plate), and the blades of each device It is also known that the blades are arranged in separate blade chambers, and each blade is always configured to obtain a suitable overlapping state in any operation, so that the blade chambers need not be divided. It is also known to do so.

Thus, the present invention provides a shutter blade and a diaphragm blade as described above, in which a rotor made of a permanent magnet that reciprocates only within a predetermined angle range is disposed in a blade chamber by an integrated output pin. The present invention relates to a camera blade driving device provided with at least two motors called the flat type among the moving magnet type motors that reciprocate any one of the filter blades.
JP 2003-186079 A

  By the way, recently, with the rapid spread of digital still cameras and the like, further downsizing and cost reduction have been demanded for the blade drive unit unit including at least two motors as described above. Yes. For this reason, it is necessary to devise various devices in the configuration of the motor itself and the mounting configuration to the ground plane. In the case of the shutter unit described in Patent Document 1, two flat type moving magnet type motors are provided. Thus, it can be said that the whole unit can be thinned (the dimension in the direction perpendicular to the ground plane can be reduced), and can be easily adopted for a thin digital still camera, an information terminal device camera, and the like.

  However, in the case of the configuration described in Patent Document 1, since the two motors are arranged with the optical axis in between, the region where the motor is not attached to the ground plane is divided into two. When this unit is incorporated in a camera, it is difficult to effectively use the space facing those areas by other camera components. The same is true when it is desired to place other members constituting the unit in these spaces. In particular, when other devices (such as a diaphragm device) are assembled in the same unit and there are three motors, there are restrictions on the arrangement of the third motor and the shape of the blades driven by the motor. In other words, it is difficult to reduce the planar shape of the entire apparatus (planar shape of the ground plane).

  In such a case, in order to enlarge the space as described above without increasing the planar shape of the entire apparatus (planar shape of the ground plane), if two motors are mounted adjacent to each other, Two large spaces will be obtained. However, simply placing the motors adjacent to each other makes it easier to place other members than before, but the space does not become larger than the sum of the previous two spaces. In addition, since the arrangement position is simply changed, the cost is not reduced even if such an arrangement is adopted. For this reason, in a camera blade drive device equipped with at least two flat-type moving magnet type motors as described above, the cost can be reduced, and the motor mounting area with respect to the main plate can be reduced as much as possible. There is a demand for realizing a configuration that can be made smaller.

  The present invention has been made to solve such problems, and the object of the present invention is to suitably attach two motors for operating each blade individually to the main plate. In addition, it is possible to provide a camera blade driving device that can reduce the cost and can reduce the attachment area to the main plate.

  In order to achieve the above object, a camera blade driving device according to the present invention comprises a main ground plate constituting a blade chamber between an auxiliary ground plate and at least one blade, each of the blade chamber. The first blade and the second blade that are rotatably attached to one of the two ground plates, and the motor frame that forms a motor chamber between the main ground plate, and each has a permanent magnet. An output pin that is supported by at least one of the main base plate and the motor frame in the motor chamber and that is provided at a radial position of each rotation shaft passes through each hole formed in the main base plate. The first rotor and the second rotor individually connected to the first blade and the second blade in the blade chamber and the two rotors in the motor chamber are disposed between the first rotor and the first rotor. Two legs extending to the rotor side The first coil is wound on one side and the tips of the legs are opposed to the first rotor, and the second coil is wound on one of the two legs extended to the second rotor side. And a plate-shaped yoke with the tip of the leg facing the second rotor. In that case, it is preferable that the yoke has at least one cut-out portion by a notch or a hole at a substantially central portion between the first rotor and the second rotor. In addition, the blade chamber is divided into two blade chambers by an intermediate plate, the first blade is disposed in one blade chamber, and the second blade is disposed in the other blade chamber. It may be.

  In the camera blade drive device of the present invention, the yoke constituting the two motors is a single component, and the yoke is interposed between the main plate and the single stator frame. Since there are two rotors, the number of parts can be reduced and costs can be reduced, compared to the case where two independent motors are mounted adjacent to the ground plane, and the mounting area for the ground plane is reduced. This is advantageous in that the entire camera can be downsized.

  Embodiments of the present invention will be described with reference to the illustrated examples. FIG. 1 is a plan view showing an initial state (photographing standby state) of the embodiment, and FIG. 2 is a cross-sectional view showing a main part of FIG. FIG. 3 is a plan view showing a state immediately after the end of photographing when photographing is performed without operating the diaphragm blades from the state of FIG. 1, and FIG. 4 is a diagram showing the state in which the diaphragm blades are operated from the state of FIG. It is a top view which shows the state immediately after completion | finish of imaging | photography in the case of having image | photographed in this.

  The camera blade drive device of the present embodiment is configured with a shutter device and a diaphragm device as one unit, and can be adopted in a digital camera such as a digital still camera or an information terminal device camera. It can also be adopted for silver halide cameras by simple changes. First, the configuration of this embodiment will be described with reference to FIGS. The main base plate 1 and the auxiliary base plate 2 are attached to each other by an appropriate means not shown. An intermediate plate 3 is attached between the main ground plate 1 and the auxiliary ground plate 2, and two blade chambers are formed between them. The three plate members 1, 2 and 3 have substantially the same outer shape, and circular opening portions 1a, 2a and 3a for the photographing optical path are formed in the substantially central portion. FIG. 1 shows a part of the main base plate 1 and the intermediate plate 3 cut away. As is well known, of the openings 1a, 2a, and 3a, any opening may regulate the exposure opening. In the following, it is assumed that the opening 1a regulates. explain.

  The main base plate 1 is made of synthetic resin and has two arc-shaped long holes 1b and 1c. The auxiliary base plate 2 and the intermediate plate 3 also correspond to the long holes 1b. The long holes 2b and 3b having the same shape are formed, and the long holes 2c and 3c having the same shape are formed at positions corresponding to the long holes 1c. However, since the intermediate plate 3 is a very thin member, the long holes 3b and 3c cannot be clearly shown in FIG. 2, and the reference numerals thereof are also omitted. Further, shafts 1d and 1e and positioning pins 1f are provided on the surface of the main base plate 1 outside the blade chamber, and shafts 1g, 1h and 1i are provided on the surface on the blade chamber side. Then, as shown in FIG. 2, the blade chamber side shafts 1g, 1h, 1i pass through holes in the intermediate plate 3 which are not clearly shown, and their tips are formed in holes 2d, 2e and 2f are inserted.

  Two flat-type moving magnet type motors are attached to the surface of the main base plate 1 outside the blade chamber. The rotor 4 of the shutter device motor is made of a permanent magnet together with an output pin 4a provided at a radial position, and is rotatably attached to the shaft 1d. The cylindrical portion is magnetized so as to have two poles in the radial direction. Further, the output pin 4 a is inserted into the blade chamber from the long hole 1 b, and its tip is inserted into the long hole 3 b of the intermediate plate 3 and is inserted into the long hole 2 b of the auxiliary base plate 2. On the other hand, the rotor 5 of the diaphragm motor also has the same configuration as the rotor 4, and the output pin 5a provided at the radial position is inserted into the blade chamber from the elongated hole 1c. The tip is passed through the long hole 3 c of the intermediate plate 3 and inserted into the long hole 2 c of the auxiliary base plate 2.

  The yoke 6 of the present embodiment has a notch 6a and a positioning hole 6b in a substantially central portion, and the positioning hole 6b is fitted to the positioning pin 1f of the main base plate 1. The yoke 6 has two leg portions 6c and 6d extending to one rotor 4 side and two leg portions 6e and 6f extending to the other rotor 5 side. The tip is used as a magnetic pole part, and is opposed to the circumferential surface of each of the rotors 4 and 5. The leg portions 6c and 6e are fitted with bobbins 9 and 10 around which the coils 7 and 8 are wound. The bent portions are formed at the ends of the leg portions 6d and 6f so as to extend further from the magnetic pole portion. 6g and 6h are formed, and in the initial state shown in FIG. 1, the output pins 4a and 5a of the rotors 4 and 5 can approach the bent portions 6g and 6h. Note that the positioning hole 6b is formed as a long hole having a predetermined length in the vertical direction of FIG. 1, and not only serves for positioning but also has an efficient magnetic path as will be described later. It is also useful for forming.

  The motor frame 11 constitutes a motor chamber between the main base plate 1 and the positioning pin 1f of the main base plate 1 is fitted into the positioning hole 11a formed in the substantially central portion of the positioning hole 11a. The shafts 1d and 1e of the main base plate 1 are fitted into the holes 11b and 11c formed on both sides. The motor frame 11 is also formed with escape holes 11d and 11e for receiving part of the bobbins 9 and 10 around which the coils 7 and 8 are wound. The motor frame 11 is attached to the main base plate 1 with three screws 12, 13 and 14 at the center and both ends.

  Two shutter blades 15 and 16 are arranged in the blade chamber formed between the main base plate 1 and the intermediate plate 3. Among them, the shutter blade 15 is rotatably attached to the shaft 1g of the main base plate 1, and the output pin 4a of the rotor 4 is inserted into the elongated hole 15a. The other shutter blade 16 is rotatably attached to the shaft 1h of the main base plate 1, and the output pin 4a of the rotor 4 is inserted into the elongated hole 16a. One diaphragm blade 17 is arranged in the blade chamber formed between the intermediate plate 3 and the auxiliary base plate 2. The diaphragm blade 17 is rotatably attached to the shaft 1i of the main base plate 1, and the output pin 5a of the rotor 5 is inserted into the elongated hole 17a. The diaphragm blade 17 is formed with an opening 17b having a smaller diameter than the opening 1a of the main base plate 1.

  Next, the operation of this embodiment will be described. FIG. 1 shows the initial state of the present embodiment. At this time, the camera is turned on, and the shutter blades 15 and 16 fully open the opening 1a (exposure opening). In the camera, a solid-state imaging device (not shown) is disposed at a lower position in FIG. 2 and exposed to subject light, and the subject image is observed on a liquid crystal monitor via an image processing circuit (not shown). It is possible. At this time, the two coils 7 and 8 are not energized. However, the output pin 4a of the rotor 4 is a permanent magnet, and the bent portion 6g of the yoke 6 is disposed in the vicinity of the output pin 4a. The attracted force is working, and the rotor 4 is biased with a force that rotates clockwise. Therefore, the shutter blades 15 and 16 connected to the output pin 4a are brought into contact with a stopper (not shown) by the biasing force, and the fully open state of the opening 1a is reliably maintained. Yes. The other rotor 5 has a force attracted by the bent portion 6h acting on the output pin 5a and the vicinity thereof, and a force rotating counterclockwise is urged. Therefore, the diaphragm blade 17 connected to the output pin 5a is brought into contact with a stopper (not shown) by the urging force, and the retracted state from the opening 1a is reliably maintained.

  When the release button is pressed at the time of shooting, it is determined based on the measurement result of the photometry circuit whether the shooting should be performed without reducing the shooting light or whether the shooting should be performed with the reduced light. When it is determined that shooting should be performed without reducing the shooting light, shooting is started immediately without operating the aperture device, but when it is determined that shooting should be performed with the shooting light reduced, Shooting is started after the aperture device is activated.

  Therefore, first, the former case will be described. In this case, the charge accumulated in the solid-state imaging device is immediately released, and accumulation of charge for photographing is newly started. When a predetermined time elapses, a current is supplied to the one coil 7 in a predetermined direction. Therefore, a magnetic pole appears in the magnetic pole part at the tip of the leg parts 6c, 6d, and the rotor 4 is rotated counterclockwise. At this time, since the yoke 6 has the four leg portions 6c, 6d, 6e, and 6f, the magnetic path is separated, and the magnetic force generated in the magnetic pole portions of the leg portions 6c and 6d is weakened, and the rotor 4a. The driving force of the other rotor 5a may not be maintained due to the small driving force or the magnetic force generated in the shunt, but in the case of the yoke 6 of the present embodiment, it is approximately at the center. Since the two cut portions of the cut portion 6a and the positioning hole 6b are formed, the cross-sectional area at the substantially central portion is reduced and the magnetic flux passing therethrough is saturated. It does not occur.

  Thus, when the rotor 4 is rotated counterclockwise, the shutter blades 15 and 16 are rotated in opposite directions by the output pin 4a, and the opening portion 1a is closed. Then, after the opening 1a is completely closed, the shutter blade 15 comes into contact with a stopper (not shown), and the closing operation ends. FIG. 3 shows a state in which the rotation of the rotor 4 and the shutter blades 14 and 15 is thus stopped. Then, in the state shown in FIG. 3, the imaging information photoelectrically converted by the solid-state imaging device is transferred to the storage device via the image processing circuit. Thereafter, a current is supplied to the coil 7 in the opposite direction. As a result, the rotor 4 rotates clockwise, and the shutter blades 15 and 16 are opened by the output pin 4a. Then, when the opening 1a is fully opened and the shutter blade 15 comes into contact with a stopper (not shown), the opening operation is finished. Thereafter, when the power supply to the coil 7 is cut off, the initial state of FIG. become.

  Next, in the initial state of FIG. 1, a case where the release button is pressed and it is determined that shooting is performed by reducing the shooting light based on the measurement result by the photometry circuit will be described. We will make it simple or omit. In this case, first, a current is supplied to the coil 8 in a predetermined direction. As a result, the magnetic poles appear at the magnetic poles at the tips of the legs 6e and 6f, so that the rotor 5 is rotated in the clockwise direction. Even if the yoke 6 is a single member, the rotor 4 has already been described. The stopped state is maintained for the reason. Then, as the rotor 5 rotates clockwise, the output pin 5a rotates the diaphragm blade 17 counterclockwise and enters the opening 1a. Thereafter, when the aperture 17b reaches a position centered on the optical axis, the diaphragm blade 17 is brought into contact with a stopper (not shown) and stopped. As a result, the photographing optical path is regulated by the opening 17b having a diameter smaller than that of the opening 1a.

  In this way, when the operation of the diaphragm blade 17 is stopped, the charge that has been accumulated in the solid-state image sensor until then is released, and the accumulation of charges for photographing is newly started. When a predetermined time has elapsed, as already described, the other coil 7 is energized, and the rotor 4 rotates counterclockwise, thereby causing the shutter blades 15 and 16 to perform a closing operation. This energization does not affect the stopped state of the other rotor 5. FIG. 4 shows a state in which the shutter blades 15 and 16 are stopped by a stopper (not shown) after the opening 17b of the diaphragm blade 17 is closed in this way. After that, when imaging information photoelectrically converted by the solid-state imaging device is transferred to the storage device, a current is supplied to the coil 7 in the opposite direction, so that the rotor 4 rotates in the clockwise direction and the shutter. The blades 15 and 16 are opened. Then, the opening operation is stopped by contacting a stopper (not shown).

  When the opening operation of the shutter blades 15 and 16 is completed, a current is supplied to the coil 8 in the reverse direction. Therefore, the rotor 5 is rotated counterclockwise, and the diaphragm blade 17 is rotated clockwise by the output pin 5a. Thereby, the aperture blade 17 is retracted from the opening 1a of the main base plate 1 and is brought into contact with a stopper (not shown) to stop its return operation. Thereafter, when the energization of the two coils 7 and 8 is cut off, the initial state of FIG. 1 is restored. In the above description, the case where the aperture blade 17 starts the return operation after the shutter blades 15 and 16 have finished opening has been described. However, the return operation of the aperture blade 17 is performed when the shutter blades 15 and 16 are opened. If it is after closing the part 17b, it does not interfere even if it starts.

  Finally, in the present embodiment, it is possible to adopt a silver salt camera by changing a part of the shape of the yoke 6, so the case of doing so will be described. In this case, the state shown in FIG. 3 is the initial state. Therefore, in order to maintain the shutter blades 15 and 16 in the closed state even when the coil 7 is not energized, a bent portion having the same function as the bent portion 6g formed in the leg portion 6d of the yoke 6 is used. Must be formed by extending the leg portion 6c. First, when photographing without reducing the photographing light, a current is supplied only to the coil 7 to fully open the shutter blades 15 and 16 as shown in FIG. Return to the initial state. Further, when taking a picture by reducing the photographic light, in the initial state of FIG. 3, first, the coil 8 is energized, and the diaphragm blade 17 is actuated to the state of FIG. Thereafter, the coil 7 is energized, the shutter blades 15 and 16 are sequentially opened and closed, and finally the current supply direction to the coil 8 is reversed to return to the initial state of FIG.

  As described above, according to the present embodiment, only one yoke 6 is provided for the two rotors 4 and 5, so that the conventional yoke which requires each yoke for each rotor. Compared to the same type of blade driving device for cameras, the number of parts is reduced and the cost can be reduced. Conventionally, the motor frame is prepared separately, and two screws are required for attaching the motor frame to the main base plate 1. In the present embodiment, one motor frame 11 and three screws 12 are used. , 13, and 14 are also advantageous in that respect. Further, since the number of yokes 6 is one, a space that has to be provided for a fixing member such as a screw is unnecessary between the two yokes as in the prior art. Since the two rotors 4 and 5 can be brought close to each other, the mounting area with respect to the main base plate 1 is also reduced, and in particular, utilization of the entire space in the camera is advantageous.

  In this embodiment, the rotor 4 drives the two shutter blades 15 and 16, but if the opening 1a can be closed by only one of the shutter blades, the shutter blade It may be one. In this embodiment, the two rotors 4 and 5 drive the shutter blades 14 and 15 and the diaphragm blade 17, but one rotor drives the shutter blades, and the other rotor The filter blades may be driven, or one rotor may drive the diaphragm blades and the other rotor may drive the filter blades. Further, as described in Patent Document 1, one rotor may drive an opening shutter blade, and the other rotor may drive a closing shutter blade. Further, the two rotors may be configured to drive two diaphragm blades having openings having different diameters separately, and the two rotors may be two filters having different amounts of transmitted light. The blades may be driven separately.

  Furthermore, the present embodiment is an example in which the present invention is applied to a camera blade driving device having two rotors. However, the present invention is applied to an apparatus having three or more rotors. It doesn't matter. That is, in the case of a device with three rotors, only two of them need be attached to the main ground plate together with a common yoke as in this embodiment, or a device with four rotors. In this case, two of them may be configured as in the present embodiment. In this case, as can be seen from FIG. 1, in the case of the present embodiment, the motor mounting area with respect to the main base plate 1 is less than half. It turns out that in some cases it is impossible to do so.

It is the top view which showed the initial state (photographing standby state) of the Example. It is sectional drawing which cut | disconnected and showed the principal part of FIG. FIG. 2 is a plan view showing a state immediately after the end of photographing when photographing is performed without operating the diaphragm blades from the state of FIG. 1. FIG. 2 is a plan view showing a state immediately after the end of photographing when photographing is performed with the aperture blades activated from the state of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main ground plate 1a, 2a, 3a, 17b Opening 1b, 1c, 2b, 2c, 3b, 4c, 15a, 16a, 17a Long hole 1d, 1e, 1g, 1h, 1i Axis 1f Positioning pin 2 Auxiliary ground plate 2d, 2e , 2f, 11b, 11c hole 3 intermediate plate 4, 5 rotor 4a, 5a output pin 6 yoke 6a notch 6b, 11a positioning hole 6c, 6d, 6e, 6f leg 6g, 6h bent part 7, 8 coil 9, 10 Bobbin 11 Motor frame 11d, 11e Escape hole 12, 13, 14 Screw 15, 16 Shutter blade 17 Stopper blade

Claims (3)

  A main ground plate constituting a blade chamber between the auxiliary ground plate and a first ground plate, each of which is composed of at least one blade, and is rotatably attached to one of the two ground plates in the blade chamber. A motor frame constituting a motor chamber between the blade and the second blade, and the main base plate, each having a permanent magnet, and bearings on at least one of the main base plate and the motor frame in the motor chamber An output pin provided at a radial position of each rotating shaft is passed through each hole formed in the main base plate and individually connected to the first blade and the second blade in the blade chamber. A first coil is wound around one of the first and second rotors and the two leg portions disposed between the two rotors in the motor chamber and extending toward the first rotor. Turn the tips of those legs to the first time A plate-like yoke having a second coil wound around one of the two leg portions facing the second rotor and extending toward the second rotor side, with the tips of the leg portions facing the second rotor; And a blade driving device for a camera.   2. The camera blade according to claim 1, wherein the yoke has at least one cut-out portion formed by a cut portion or a hole at a substantially central portion between the first rotor and the second rotor. Drive device. The blade chamber is divided into two blade chambers by an intermediate plate, the first blade is disposed in one blade chamber, and the second blade is disposed in the other blade chamber. The camera blade drive device according to claim 1 or 2.