JPH1055007A - Blade driving mechanism for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preferable blade driving mechanism suitable for arranging in a peripheral position of an exposure aperture. SOLUTION: Two yokes 12 are arranged to hold a permanent magnet rotor 6 in between. Each yoke 12 is provided with a magnetic pole part 12a whose end face is confronted with the periphery of the rotor 6 and two winding parts 12b and 12c bent in parallel with the rotary shaft of the rotor 6. Bobbins 15 and 16 on which coils are wound are fitted to the winding parts 12b and 12c. Then, the respective coils wound on the bobbins 15 and 16 are simultaneously energized to obtain the same polarity in the magnetic pole parts 12a. Thus, the coils are arranged in a state where they are divided into two parts, so that a dimension required in an optical axial direction can be made smaller without making an arrangement dimension in a radial direction from an optical axis larger.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera blade driving mechanism in which at least one light shielding blade functioning as a shutter blade or an aperture blade is operated using a motor as a driving source.

[0002]

2. Description of the Related Art A pulse motor is often used as a motor for this type of drive mechanism.
It is known from JP-A-0-140934. In this motor, the rotor is made of a permanent magnet, but the coil is not arranged along the inner wall surface of the cylindrical case as in a general motor. In this motor, two iron cores each having two magnetic pole portions are arranged so as to sandwich a rotor, and a coil is wound around one magnetic pole portion of each iron core. The two iron cores are arranged in a C shape along the periphery of the exposure opening. For this reason, the mounting dimension in the radial direction from the optical axis is smaller than that of the above-described general motor, which is advantageous in that it is arranged near the lens.

[0003] However, this motor can have a smaller mounting dimension in the radial direction than that of the above-mentioned general motor, but has a mounting space (an angular range centered on the optical axis) occupying a plane perpendicular to the optical axis. ) Becomes very large. In addition, since each magnetic core has a magnetic pole portion wound with a coil and a magnetic pole portion not wound with a coil arranged on the same vertical plane with respect to the optical axis, the mounting dimension in the radial direction is further reduced. It is impossible to make it smaller than this and make it close to the winding diameter of the coil. In order to improve such a point, a configuration in which the winding diameter of the coil is arranged so as to be parallel to a plane perpendicular to the optical axis, that is, a configuration in which the winding axis of the coil is parallel to the optical axis. Have been filed by the present applicant and are being developed based thereon.

An example will be described with reference to FIGS. 8 to 10. This example is a driving mechanism of an aperture blade for a single-lens reflex camera, and FIG. 8 is a plan view partially showing the driving mechanism. FIG. 9 is a sectional view of a main part of FIG. 8, and FIG. 10 is a plan view of a motor unit. First, the configuration will be described. The base plate 1 is made of synthetic resin, and has a circular opening 1a formed at the center thereof with the optical axis as the center. In FIG. 8, a cover plate 2 (FIG. 9) having substantially the same shape is attached to the rear side of the base plate 1, and although not shown, an opening of substantially the same shape is formed at the center thereof. The opening forms an exposure opening. Three diaphragm blades 3 are accommodated in a blade chamber provided between the main plate 1 and the cover plate 2, and are rotatably attached to the pins 1 b of the main plate 1. Note that FIG. 8 shows only one of them, and the fully open position is indicated by a dotted line, and the closed position is indicated by a dashed line.

The drive ring 4 aligns the notches 4a formed at three places with the retaining portions 1c formed on the base plate 1, is fitted into the circular grooves 1d, and is rotatable about the optical axis. Have been. The three pins 4b provided on the drive ring 4 pass through holes 1e formed in the base plate 1 in an arc shape and cam holes 3a formed in the aperture blade 3, respectively. It is fitted in the groove 2a formed in an arc shape. The motor frame 5 is made of synthetic resin and has two pins 5.
a is fitted to the hole 1f of the base plate 1 and the two hook portions 5b having flexibility are engaged with the locking portions 1g of the base plate 1, thereby being attached to the base plate 1. The motor frame 5
The two pins 5c provided on the front surface side are for attaching a printed wiring board (not shown).

A rotor 6 having permanent magnets magnetized to four poles is supported by a base plate 1 and a motor frame 5 as shown in FIG. 9, and a toothed portion 6 is provided below a synthetic resin shaft.
a is formed. A parent-child gear 7 is provided on the shaft portion 1h of the main plate 1.
Are rotatably mounted, and the parent gear meshes with the teeth 4 c of the drive ring 4. Two yokes (iron core) 8
Are on both sides of a line connecting the rotation axis of the rotor 6 and the optical axis,
They are arranged symmetrically. Their arrangement and shape are
FIG. 10 is easier to understand than FIG. As shown in FIG. 9, each yoke 8 has one magnetic pole portion 8a extending perpendicular to the optical axis and a winding portion 8b extending parallel to the optical axis. A projecting portion 8c is formed at the position, and a coupling portion 8d is formed at the tip of the winding portion 8b.

A bobbin 10 around which a coil 9 is wound is fitted in each of the winding portions 8b, and each projecting portion 8c is fitted in a groove 1i formed in a thick portion of the base plate 1, respectively. Each magnetic pole portion 8a is opposed to the peripheral surface of the rotor 6. The two yokes 8 are connected to each other by fitting the respective connecting portions 8d into the holes of the connecting yoke 11. In addition, the above-described motor frame 5
The two pins 5d and the bearing portion 5e of the rotor 6 are fitted in holes formed in the connecting yoke 11, respectively, while the magnetic pole portion 8a of the yoke 8 is By being supported by the tip, the combined body of the connecting yoke 11 and each yoke core 8 is positioned. Note that FIG.
Is mounted with the parent-child gear 7 as described above, but the other shaft (1h) (not shown) supporting the other yoke 8 is not mounted at all. Therefore, it may be more appropriate to call it a pedestal rather than a shaft.

Next, the operation will be briefly described. Since this drive mechanism is an aperture blade drive mechanism for a single-lens reflex camera, the initial position of the aperture blade 3 is the position indicated by the one-dot chain line in FIG. 8 and closes the opening 1a. Accordingly, the drive ring 4 is at a position rotated clockwise from the state shown in FIG. It goes without saying that, depending on the specifications of the camera, a state in which the opening 1a is not completely closed may be set as the initial position. In this state, when the power switch is closed prior to photographing, the coil 9 is energized, and the rotor 6 rotates counterclockwise in FIG. The rotation of the tooth 6a
Is transmitted to the drive ring 4 via the parent and child gears 7. Therefore, the drive ring 4 rotates counterclockwise, and the aperture leaf 3 fully opens the opening 1a. The fully opened state is the state shown in FIG. 8, and the diaphragm blade 3 is at the position shown by the dotted line.

When the shutter is released in this state, the coil 9 is energized immediately before and after the mirror is raised, and the rotor 6 rotates clockwise. Therefore, the drive ring 4 also rotates clockwise via the parent and child gears 7 to cause the aperture blade 3 to perform the closing operation and stop at a predetermined aperture diameter position. After that, the shutter is opened and closed, and when it is completed,
The mirror returns to its original position and the coil 9 is energized,
The rotor 6 is rotated counterclockwise. Therefore, the aperture blade 3 is opened by the drive ring 4 to be fully opened and stopped. In this state, the next photographing is performed. If the photographing is not performed, when the power switch is opened, power is supplied for a predetermined time, and the rotor 6 rotates clockwise. , Stops immediately after the aperture blade 3 closes the opening 1a.

In this driving mechanism, as can be seen from FIG. 8, the mounting dimensions of the motor in the radial direction from the optical axis are as follows.
It is substantially regulated by the winding diameter of the coil (actually, the shape of the bobbin). Therefore, the mounting dimensions in the radial direction from the optical axis are the same as those described in the above-mentioned Japanese Utility Model Publication No. 60-140934.
Than that described in Japanese Patent Laid-Open Publication No. H10-209, the arrangement of the magnetic pole portion where the coil is not wound can be reduced, and the mounting angle range as viewed from the optical axis is further reduced, so that the space of the mounting surface is extremely reduced. It has become possible.

[0011]

However, recent demands for miniaturization of cameras are extremely strong, and this is particularly spurred by the appearance of IX240 film (APS film). Therefore, it is urgently necessary to further reduce the size of this type of blade drive mechanism.
By the way, when downsizing this kind of blade drive mechanism, as described above, the mounting dimension in the radial direction from the optical axis,
That is, how to reduce the dimension in the radial direction from the periphery of the exposure opening and how to reduce the mounting dimension in the optical axis direction, that is, how to reduce the vertical dimension in FIG. The present invention has been made to solve such a problem, and an object thereof is to make it possible to further reduce the size of the driving mechanism described with reference to FIGS. An object of the present invention is to provide a blade driving mechanism for a camera.

[0012]

In order to achieve the above object, a camera blade driving mechanism according to the present invention comprises a base plate having an exposure opening, and at least one opening / closing opening / closing opening for the exposure opening.
A plurality of light-shielding blades, a rotor having permanent magnets magnetized to a plurality of poles, and having a rotation axis parallel to the optical axis and arranged at a side position of the exposure opening; and a rotation axis of the rotor. And a plurality of windings each extending in parallel to the rotation axis of the rotor and having one surface having a surface facing the peripheral surface of the rotor within a predetermined angle range and perpendicular to the rotor. And a driving member actuated by the rotation of the rotating shaft to cause the light-shielding blade to open and close, wherein the coils wound around the plurality of winding portions are energized at the same time by the magnetic pole portion. , So that the same polarity can be generated.
In the blade driving mechanism for a camera according to the present invention, preferably, the stator is provided with another magnetic pole portion having a surface facing a peripheral surface of the rotor within a predetermined angle range. The magnetic pole portions are arranged so as to sandwich the rotor. Alternatively, in the camera blade driving mechanism of the present invention, preferably, two stators are provided, and these are arranged such that respective magnetic pole portions sandwich the rotor.

[0013] In the blade driving mechanism for a camera according to the present invention, preferably, the two stators are magnetically coupled by a connecting member made of a magnetic material. In the blade driving mechanism for a camera according to the present invention,
Preferably, at least one of the plurality of winding portions is formed by bending the magnetic pole portion. In the blade driving mechanism for a camera according to the present invention,
Preferably, a magnetic member is provided on the stator in parallel with the magnetic pole portion, and at least one of the plurality of winding portions is at least one of the magnetic member and the magnetic pole portion. So that it is formed by bending one. In the blade driving mechanism for a camera according to the present invention,
Preferably, the stator is provided with a magnetic member arranged in parallel with the magnetic pole portion, and at least one of the plurality of winding portions is a magnetic member connecting the magnetic member and the magnetic pole portion. Be a stick. Further, in the camera blade driving mechanism of the present invention, preferably, the magnetic member is the connecting member.

Further, in the blade driving mechanism for a camera according to the present invention, preferably, at least one of the starting and stopping of the rotor energizes all the coils wound around the plurality of winding portions, During other rotations, some coils are energized. In the camera blade drive mechanism of the present invention, preferably, when the coil is energized in the forward direction, the rotor is rotated in one direction,
When power is supplied in the opposite direction, the motor is rotated in the other direction. In the blade driving mechanism for a camera according to the present invention,
Preferably, the rotor is rotated in one direction when the coil of one of the two stators is energized, and the rotor is rotated in the other direction when the coil of the other stator is energized. To do. Further, in the blade driving mechanism for a camera according to the present invention, preferably, when the coil of one of the two stators is energized in the forward direction, the coil of the other stator is energized in the opposite direction. Then, when the coil of the one stator is energized in the reverse direction, the coil of the other stator is energized in the forward direction.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to an embodiment shown in FIGS. Further, three modified examples of the motor unit in the embodiment will be described with reference to FIGS. FIG. 1 is a plan view showing a part in a see-through state, and FIG. 2 is a sectional view of a main part of FIG. 3 and 4 are diagrams for explaining the operation of the motor in the embodiment. FIG. 3 is an explanatory diagram when the rotor of the motor is rotated in a counterclockwise direction. FIG. It is explanatory drawing at the time of rotating to. 5 to 7 are cross-sectional views showing modified examples of the stator of the motor.

First, the configuration of the embodiment will be described. This embodiment is also an embodiment implemented as a diaphragm blade driving mechanism for a single-lens reflex camera, similarly to the embodiment described with reference to FIGS. For this reason, the components and parts constituting the present embodiment are substantially the same as those described with reference to FIGS. 8 to 10, and therefore, the same components are denoted by the same reference numerals and detailed description thereof will be omitted. Only different configurations will be described. This embodiment is different mainly in the configuration of the stator of the pulse motor having the four-pole magnetized rotor. Each of the two yokes 12 has one magnetic pole portion 12a whose end face is opposed to the peripheral surface of the rotor 6, and two winding portions 12b which are bent at substantially 90 degrees and extend parallel to the optical axis. 12c. Further, the projecting portion 12 is located near the magnetic pole portion 12a.
d are connected to the leading ends of the winding portions 12b and 12c, respectively.
2e and 12f are formed. It should be noted that the plan shape of the yoke 12 is easier to understand in FIG. 3 than in FIG.

The winding portions 12b and 12c are fitted with bobbins 15 and 16 around which coils 13 and 14 are wound, respectively, and the projecting portions 12d are formed in the thick portion of the base plate 1 respectively. Into the groove 1i. Coil 13, 14
Are connected in series to a power supply, and are wound so as to generate the same polarity with respect to the magnetic pole portion 12a when energized. If the magnetic pole portion 12a is wound so as to have the same polarity, the magnetic pole portion 12a may be individually connected in parallel to the power supply. Also,
Each of the coupling portions 12e and 12f is fitted in a separate hole formed in the connection yoke 17. Further, as described above, the stator, which is such a combined body, has the protruding portion 12d fitted in the groove 1i and the hole formed in the connecting yoke 17 in the bearing portion 5e of the rotor 6 as described above. The position is regulated by fitting the magnetic pole portion 18a into contact with the tip of the shaft portion 1h.

Next, the operation of this embodiment will be described. The operation of the aperture blade driving mechanism for a single-lens reflex camera is shown in FIG.
10 is the same as that of the example shown in FIG. 10, so that the rotation control of the motor will mainly be specifically described here. As described above, the rotor 6 of this motor is magnetized to four poles. Therefore, the peripheral surface of each pole has an angle range of 90 degrees. On the other hand, the magnetic pole portion 12a only has the opposing surfaces in an angle range narrower than 90 degrees, and the two magnetic pole portions 12a are arranged at a slight angle with respect to the rotation axis of the rotor 6. is there. Therefore, in the non-energized state shown in FIG. 3A, the right N pole is attracted clockwise in relation to the right magnetic pole part 12a, and the left N pole is left magnetic pole part 1a.
In other words, it is sucked counterclockwise in relation to 2a. In the present embodiment, such a contradictory positive force acts to stabilize the stop position of the rotor 6 when no power is supplied.

In the stable non-energized state shown in FIG. 3A, when it is desired to rotate the rotor in the counterclockwise direction, only the right coils 13 and 14 are energized in the positive direction. Then, as shown in FIG. 3B, an N pole appears in the right magnetic pole portion 12a. As described above, since the right yoke 12 is connected to the left yoke 12 by the connection yoke 17, at this time, the magnetic pole portion 1 of the left yoke 12
The S pole appears weak in 2a. Therefore, the rotor 6 rotates counterclockwise and stops in a balanced state in the state of FIG. As described above, when the rotor 6 rotates in the counterclockwise direction, the diaphragm blades 3 perform the opening operation. Therefore, the stop position in FIG.
For example, the position is F16.

Next, in the state shown in FIG. 3 (c), when only the right coils 13 and 14 are energized in the opposite direction, the state shown in FIG.
As shown in the figure, the S pole appears at the right magnetic pole portion 12a, and the N pole weakly appears at the magnetic pole portion 12a of the left yoke 12. As a result, the rotor 6 further rotates counterclockwise, as shown in FIG.
Stop in the state of. In this state, the diaphragm blade 3
The aperture for exposure is regulated, for example, to the aperture of F8. The state in which the energization is cut off in the state of FIG. 3E is the same as the state of the motor in FIG. 3A even though the rotor 6 has rotated 180 degrees counterclockwise. Accordingly, in the state shown in FIG. 3E, only the right coils 13 and 14 are energized in the positive direction, and the operation is stopped in the state shown in FIG. 3C through the state shown in FIG. 3B. In this manner, the rotor 6 is sequentially rotated in the counterclockwise direction, so that the aperture blade 3 is rotated.
In the fully opened state of FIG. 1 (the dotted line position of the aperture blade 3).

In this embodiment, the stop position of the rotor 6 in the fully opened state of the diaphragm blade 3 is as shown in FIG. This state is the same as the state shown in FIG. 3A for the rotor 6, and the stable state is maintained as described above. When the shutter is released in this state, only the left two coils 13 and 14 are energized in the forward direction. Then, as shown in FIG. 4B, an N pole appears in the left magnetic pole portion 12a, and the right yoke 12
The S pole appears weak in the magnetic pole portion 12a. Therefore, the rotor 6 rotates clockwise, and the diaphragm blade 3 performs the closing operation. The rotor 6 temporarily stops at the position shown in FIG. 4 (c), but if the position is not at the predetermined aperture position, power is supplied to the two coils 13 and 14 on the left side in the opposite direction. Thereby, as shown in FIG. 4D, the S pole appears at the left magnetic pole part 12a, and the S pole weakly appears at the right magnetic pole part 12a. Therefore, the rotor 6 further rotates clockwise and stops at the position shown in FIG.

In this way, the rotor 6 is sequentially rotated clockwise, but when it reaches a predetermined aperture position, the stopped state is maintained, and then the shutter opening / closing operation is performed. Will be When the opening / closing operation of the shutter is completed, the rotor 6 is once rotated counterclockwise as described with reference to FIG. 3, and the aperture blade 3 is fully opened to prepare for the next photographing.
If the power switch is turned off without continuing shooting,
The rotor 6 continuously performs the operation described in FIG. 4 for a predetermined time according to the signal, closes the aperture blade 3, and ends a series of operations.

In the above description, it is assumed that the rotor 6 is maintained in a stable state and occupies a predetermined position even in the non-energized state as shown in FIGS. 3 (a) and 4 (a). It was explained in. However, in practice, at the moment of the start of operation, the rotor 6 may not be in a predetermined position for an accidental reason. If there is such a concern, first, the coils 13 and 14 on the right side in the state of FIG.
To the magnetic pole portion 12a of the right yoke 12
In this case, an S pole is generated, and the rotor 6 is reliably positioned at a predetermined position. Then, as shown in FIG. Good. Similarly, when rotating clockwise from the state shown in FIG. 4A, first, an S pole is once generated in the magnetic pole portion 12a of the left yoke 12, and the rotor 6 is positioned.
What is necessary is just to make it rotate like FIG.4 (b).

In the above description, only the right coil is energized when the rotor 6 is rotated counterclockwise, and only the left coil is energized when the rotor 6 is rotated clockwise. However, for example, when rotating the rotor 6 in the counterclockwise direction, both the left and right coils may be energized simultaneously. It is needless to say that in this case, as shown in FIG. 3B, when the right coil is energized to generate an N pole in the right magnetic pole portion, the left coil is energized and the left coil is energized at the same time. The S pole may be positively generated in the magnetic pole portion of the above. Therefore, in that case, there is no problem in the operation principle even without the connecting yoke 17.

Further, in the embodiment, it is possible to rotate the rotor 6 in both the counterclockwise direction and the clockwise direction by using only one of the left and right coils. That is, for example, in the description of the embodiment, when the rotor 6 is rotated clockwise from the state of FIG. 4A, instead of energizing the left coil as described above, the right coil is reversed. What is necessary is just to energize in a direction. Then, an S pole is generated at the right magnetic pole portion, and an N pole is weakly generated at the left magnetic pole portion. In this case, since the magnetic action given to the rotor 6 is the same as that in the case of FIG. 4B, the rotor 6 rotates clockwise. Therefore, if the power is sufficiently obtained in the specification, the two coils 13 and 1 on one side are used.
4 (and bobbins 15, 16) can be omitted.

In such an extreme case,
Two coils 13, 14 on one side (and bobbins 15, 1)
Not only 6) but also the connecting yoke can be omitted. Moreover, in that case, it is possible to replace the yoke 12 on the side where the coil is omitted with a magnetic member having a simple shape. That is, the left coil 1 in FIG.
3 and 14 (and bobbins 15 and 16) are omitted and FIG.
When the connecting yoke 17 shown in FIG. 2 is also omitted,
The bent yoke 12 may be disposed as it is, but a magnetic member having a simple shape may be disposed instead. In short, depending on the arrangement of the magnetic member, a counterclockwise attractive force acts on the N pole on the left side of the rotor 6 when stopped.

Further, in the above description, the coil 1
3, 14 were wound in series. That is, the terminals of the coil 13 and the coil 14 are common, and energization and non-energization cannot be separately controlled. However, if the terminals are separated and wound in parallel, the rotor 6 can be controlled very conveniently. That is, the rotor 6 requires a larger force at the time of startup than when the rotor 6 is continuously rotating. In addition, it is required that a stable state be obtained immediately upon stopping. The present embodiment is an example of driving the aperture blade, but in the case of driving the shutter blade, this startability is good,
It is absolutely necessary to stop immediately at a predetermined stop position. Therefore, if the energization and de-energization can be controlled separately, the coil 1 can be controlled at such a start and stop.
3 and the coil 14, it is possible to energize only one of the coils when rotating continuously, and it is possible to save power as compared with a case where both coils are always energized simultaneously. The effect can be obtained.
Depending on the specifications, such control may be performed only at the time of starting or stopping.

As described above, according to the drive mechanism of this embodiment, the rotation axis of the permanent magnet rotor and the winding axis of the coil of the stator are arranged parallel to the optical axis, and the magnetic pole portion of the stator is rotated. In spite of the configuration facing the peripheral surface of the child, the coil is divided into two and their winding axes are arranged in parallel, so that the installation dimension in the optical axis direction can be reduced. This is shown in FIG. 2 which is drawn without changing the dimensions of other members and parts.
9 is obvious at a glance. That is, the vertical dimension in FIG. 2 is further reduced. Further, by dividing the coil into two as in the present embodiment, the winding diameter of each coil is reduced, so that the installation dimension in the radial direction of the optical axis can be reduced. Further, by dividing the coil into two, it is possible to separately control energization and non-energization as described above. As can be understood from the above description, the coil may be divided into three or more if the layout area permits.

Next, three modifications of the stator in the above embodiment will be described. In the first modified example shown in FIG. 5, the yoke 12 is formed in a flat plate shape, and the connecting yoke 17 is formed with two bent portions, which are formed into winding portions 17a and 17b. Therefore, the bobbin 15 around which the coil 13 is wound is fitted in the winding portion 17a, and the bobbin 16 around which the coil 14 is wound is fitted in the winding portion 17b.
A part of the tip of a, 17b is fitted in a hole formed in the yoke 12. In the second modification shown in FIG. 6, the winding portions 12b and 12c of the yoke 12 in the embodiment and the winding portions 17a and 17 of the connecting yoke 17 in the first modification are shown.
b are shortened together and aligned coaxially, and the winding portions 12b,
The bobbin 15 is fitted on 17a, and the bobbin 16 is fitted on the winding portions 12c and 17b. The third shown in FIG.
In the modified example, the yoke 12 in the embodiment is formed in a flat plate shape, and magnetic rods 18 and 19 are attached between the yoke 12 and the connecting yoke 17, and bobbins 15 and 16 are fitted to them. Even with such a configuration, the same operation and effect as the embodiment can be obtained. The fitting portion of the bobbin 15 and the fitting portion of the bobbin 16 do not need to have the same configuration.
The fitting part of No. 5 may be configured as in the first modification, and the fitting part of the bobbin 16 may be configured as in the second modification, including the configuration of the embodiment. It is possible.

In the above-described embodiments and modified examples, the present invention has been described as being applied to a diaphragm blade driving mechanism.
The present invention is also applied to a shutter blade driving mechanism as described in Japanese Utility Model Laid-Open No. 140934/1985. Further, the driving member in the present invention,
Not only the ring member but also a lever member or a link member may be used. Further, in the embodiment, the output of the rotor is taken out by a gear, but it may be taken out by a cam member such as an eccentric cam.

[0031]

As described above, according to the drive mechanism of the present invention, the rotation axis of the magnet rotor is arranged parallel to the optical axis, and the magnetic pole portion of the stator is fixed to the peripheral surface of the rotor by a predetermined angle range. To face each other,
Further, a plurality of coils are arranged on the stator so that each winding axis is parallel to the rotation axis, and the same polarity can be generated in the magnetic pole portion by the plurality of coils. Accordingly, it is possible to reduce the installation dimension in the radial direction of the optical axis and the installation dimension in the optical axis direction.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment partially shown in a see-through state.

FIG. 2 is a sectional view of a main part of FIG.

FIG. 3 is an explanatory diagram in a case where a rotor of a motor is rotated in a counterclockwise direction in the embodiment.

FIG. 4 is an explanatory diagram in a case where the rotor of the motor is rotated clockwise in the embodiment.

FIG. 5 is a sectional view showing a first modification of the motor stator in the embodiment.

FIG. 6 is a sectional view showing a second modification of the motor stator in the embodiment.

FIG. 7 is a sectional view showing a third modification of the motor stator in the embodiment.

FIG. 8 is a plan view of a conventional example showing a part in a see-through state.

FIG. 9 is a sectional view of a main part of FIG.

FIG. 10 is a plan view of the motor unit shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ground plate 1a Opening 1b, 4b, 5a, 5c, 5d Pin 1c Retaining portion 1d, 1i, 2a Groove 1e, 1f Hole 1g Locking portion 1h Shaft 2 Cover plate 3 Aperture blade 3a Cam hole 4 Drive ring 4a Notch 4c, 6a Tooth 5 Motor frame 5b Hook 5e Bearing 6 Rotor 7 Parent-child gear 8,12 Yoke 8a, 12a Magnetic pole 8b, 12b, 12c, 17a, 17b Winding 8c, 12d Overhang 8d, 12e , 12f Coupling parts 9, 13, 14 Coils 10, 15, 16 Bobbins 11, 17 Connecting yokes 18, 19 Magnetic rod

Claims (12)

[Claims] 1. A base plate having an opening for exposure, at least one light-shielding blade for opening and closing the opening for exposure, and a permanent magnet magnetized to a plurality of poles, having a rotation axis parallel to the optical axis. A rotor disposed at a position lateral to the exposure opening, and one magnetic pole portion having a surface disposed perpendicular to a rotation axis of the rotor and facing a peripheral surface of the rotor within a predetermined angle range. A stator having a plurality of winding portions each extending in parallel with the rotation axis of the rotor and wound with a coil, and a driving member which is operated by the rotation of the rotation shaft and causes the light shielding blade to perform an opening / closing operation. Wherein the coils wound around the plurality of winding portions can generate the same polarity in the magnetic pole portion by simultaneous energization. 2. The stator further includes another magnetic pole portion having a surface facing the peripheral surface of the rotor within a predetermined angle range, and the magnetic pole portions sandwich the rotor. The camera blade driving mechanism according to claim 1, wherein the camera blade driving mechanism is arranged in such a manner. 3. The camera blade driving mechanism according to claim 1, wherein two stators are provided, and each of the stators is arranged so that respective magnetic pole portions sandwich the rotor. . 4. The camera blade driving mechanism according to claim 3, wherein the two stators are magnetically coupled by a connecting member made of a magnetic material. 5. The blade driving mechanism for a camera according to claim 1, wherein at least one of the plurality of winding portions is formed by bending the magnetic pole portion. 6. The stator is provided with a magnetic member arranged in parallel with the magnetic pole portion, and at least one of the plurality of winding portions is provided between the magnetic member and the magnetic pole portion. The blade driving mechanism for a camera according to claim 1, wherein at least one is bent. 7. The stator further includes a magnetic member disposed in parallel with the magnetic pole portion, and at least one of the plurality of winding portions connects the magnetic member and the magnetic pole portion. The blade driving mechanism for a camera according to any one of claims 1 to 4, wherein the magnetic member is a magnetic rod. 8. A blade driving mechanism for a camera according to claim 4, wherein said magnetic member is said connecting member. 9. At least one of the start and stop of the rotor energizes all the coils wound around the plurality of winding portions, and energizes some of the coils during other rotations. The blade driving mechanism for a camera according to any one of claims 1 to 8, wherein: 10. The apparatus according to claim 1, wherein the rotor is rotated in one direction when the coil is energized in the forward direction, and is rotated in the other direction when the coil is energized in the reverse direction. A blade driving mechanism for a camera according to the above. 11. When the coil of one of the two stators is energized, the rotor is rotated in one direction, and when the coil of the other stator is energized, the rotor is rotated in the other direction. The blade driving mechanism for a camera according to any one of claims 3 to 8, wherein the blade driving mechanism is rotated. 12. When the coil of one of the two stators is energized in the forward direction, the coil of the other stator is energized in the opposite direction, and the coil of the one stator is reversed. 9. The camera blade drive mechanism according to claim 3, wherein when the power is supplied in the direction, the coil of the other stator is supplied with power in the positive direction.