JP2001356389A - Camera shutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera shutter capable of attaining an aperture control function at a low cost and with a compact constitution. SOLUTION: A permanent magnet rotator 3 is moved by a prescribed angle in accordance with the current direction of a stator coil 6 so as to open/close shutter blades 11 and 12 through a driving pin 3b. An arm part 3c is formed in the vicinity of the base part of the driving pin 3b so as to project nearly at a right angle. In the case of opening the shutter blades 11 and 12 by rotating the rotator 3 from the initial position counterclockwise, the arm part 3c comes into contact with the aperture control member 13 before the aperture part 1a is fully opened, and the opening action of the blades is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a plurality of shutter blades which rotate in opposite directions to open and close a circular exposure opening and reciprocate to a predetermined opening position smaller than the exposure opening. The present invention relates to a motor-driven camera shutter capable of performing photographing.

[0002]

2. Description of the Related Art There is known a camera shutter in which an exposure opening is opened and closed by simultaneously rotating two shutter blades in opposite directions. Further, as a modification of the configuration, there is also a configuration in which one shutter blade and two shutter blades are rotated in opposite directions, or two shutter blades are rotated in opposite directions. Are known. In such a shutter, usually, the exposure opening is opened from a substantially central portion thereof and is often closed toward the substantially central portion. By causing the shutter blade to stop at a predetermined opening position and causing the shutter blade to perform the closing operation from that position when a shooting end signal is issued, the shutter blade also serves as an aperture blade. Has become possible.

On the other hand, as means for driving the shutter blades,
A current control type motor called a moving magnet type motor is known. This motor typically has 2
An output pin (drive pin) in which a rotor made of a permanent magnet magnetized on the pole extends parallel to the rotation axis at its radial position.
And the rotor is configured to be able to rotate within a predetermined angle range in a direction corresponding to a direction of energizing the stator coil. This motor is characterized in that it can be manufactured at low cost and is easy to reduce in size.
On the other hand, when the power supply to the stator coil is cut off, the stop position of the rotor becomes unstable, and since the driving force is not so large, the opening operation tends to be particularly unstable depending on the shutter configuration. There is a problem. Therefore, many proposals have been made so far to solve those problems.

A configuration in which such a motor is used as a drive source to rotate two shutter blades in opposite directions is disclosed in Japanese Patent Application Laid-Open No. 2000-66267. Japanese Patent Application Laid-Open No. H10-307
As described in Japanese Patent No. 312, it is known that an output pin of a motor is directly connected to a shutter blade. However, the present invention does not use an opening / closing member.
The present invention relates to the latter type of camera shutter, and more particularly, to a camera shutter capable of taking a picture without opening the shutter blades fully.

[0005]

By the way, in the case of a camera shutter in which an opening / closing member is interposed and a shutter blade is opened / closed, it is possible to take a picture without opening the shutter blade fully. To this end, there are known one in which the shutter blade directly contacts the opening regulating member before full opening, and one in which the opening and closing member contacts the opening regulating member, thereby stopping the shutter blade. However, in the case of the shutter configuration which is the object of the present invention, since the opening / closing member is not provided, in order to enable such photographing, the shutter blade should be brought into direct contact with the opening regulating member. The general idea is to do so.

However, with such a configuration,
In order for the contact portion of one shutter blade to directly contact the opening regulating member, it is necessary to contact the opening regulating member only when the contact portion does not overlap with the other shutter blade. Can not. For this reason, from a normal design point of view, it is necessary to use a portion that is considerably away from the rotation axis of the shutter blade as the contact portion. In such a case, the impact at the time of abutment becomes large due to inertia, and the shutter blades generate a large bounce or deform, so that it is necessary to take measures against them. I will.

Further, the opening regulating member is attached to the shutter base plate outside the blade chamber, and the restricting portion (a portion with which the shutter blade comes into contact) must face the blade chamber. It is necessary to provide a through hole for operably inserting the restricting portion, but since the amount of operation of the contact portion of the shutter blade is extremely large, the length of the through hole is also long along the operation path of the contact portion. It must be formed, which is a problem in light leakage control. Furthermore,
If the opening restricting member is provided on the shutter base plate without enlarging the outer shape of the shutter base plate, the shape of the shutter blade having the contact portion must be unique, so that when the shutter is closed, the contact portion is exposed. Since the aperture is located directly in front of the opening, it is necessary to take measures against light leakage from the periphery of the exposure aperture.

The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a shutter device in which an opening regulating member directly opens a shutter blade performing an opening operation as described above. An object of the present invention is to provide an electric camera shutter in which an output pin (drive pin) provided in a current control type motor and directly connected to a shutter blade is directly stopped, instead of being stopped. .

[0009]

In order to achieve the above object, a camera shutter according to the present invention is capable of reciprocatingly rotating by a predetermined angle from an initial position corresponding to a direction in which a stator coil is energized. A permanent magnet rotor integrally has a drive pin extending in parallel with the rotation axis at a radial position of the rotation axis, and near a root portion of the drive pin in a direction substantially perpendicular to the drive pin. A motor having an arm protruding toward the motor; and a motor connected to a tip end of the drive pin, wherein the exposure opening is closed when the rotor is at the initial position, and in conjunction with the operation of the drive pin. A plurality of shutter blades which are relatively reciprocated to open and close the exposure opening, and the rotor which has been rotated from the initial position is stopped by inhibiting the operation of the arm, so that the shutter blades are exposed to the light; Full opening To As and an opening regulating member as may be stopped before.

In the camera shutter according to the present invention, one end of the torsion coil spring is hung on the drive pin, and biases the rotor in a direction to open the shutter blade. Thus, a favorable opening operation characteristic of the shutter blade can be obtained.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to two illustrated embodiments. FIGS. 1 to 6 are for explaining the first embodiment, and FIGS.
Is for explaining the second embodiment. FIGS. 1, 3 to 7 are plan views viewed from the subject side when incorporated in a camera, and FIGS. 2 (a) and 8 (a)
FIG. 2B is a sectional view of a main part of each embodiment, and FIG.
(B) is a left side view of each rotor shown in FIGS. 2 (a) and 8 (a).

[First Embodiment] First, the configuration of this embodiment will be described with reference to FIGS. The shutter base plate 1 is made of a synthetic resin, and a blade chamber is formed between the shutter base plate 1 and an auxiliary base plate 2 also made of a synthetic resin, and both are attached to each other by a plurality of screws (not shown). Also, shutter base plate 1
And circular openings 1a, 2a in the center of the auxiliary base plate 2.
Are formed, and the exposure openings are formed by arranging the openings 1a and 2a concentrically. Further, a cutout portion 1b is formed in the shutter base plate 1, and a groove 2b having the same planar shape as the cutout portion 1b is formed in the auxiliary base plate 2.

The above-described moving magnet type motor is mounted on the front side of the shutter base plate 1, that is, on the subject side. However, only the rotor 3 is shown in FIG. 1 to make it difficult to see the drawing. Therefore, first, the rotor 3 has a two-pole permanent magnet magnetized in the radial direction, and extends in parallel with the rotary shaft 3a at the radial position of the rotary shaft 3a. A drive pin 3b formed as described above, and an arm 3c protruding at a substantially right angle on the root side of the drive pin 3b are provided. In this embodiment, the rotation shafts 3
a, the drive pin 3b and the arm 3c are made of synthetic resin,
Although they are integrally formed by outsert processing, as is well known, they do not prevent the use of permanent magnets. The boundary between the two poles of the permanent magnet is a line passing through the rotation shaft 3a and the drive pin 3b in FIG.

As shown in FIG. 2, the stator frame of the present embodiment is composed of an upper frame 4 and a lower frame 5 made of a synthetic resin. The frames 4 are attached to each other by a plurality of hook portions 4a (only one is shown in FIG. 2). The lower frame 5 has an arc-shaped long hole 5a centered on the rotation shaft 3a.
The drive pin 3b is penetrated there. And
A coil 6 is wound so as to cover the bearing portions of the upper frame 4 and the lower frame 5. A cylindrical yoke 7 is fitted on the outer peripheral surface of the cylindrical upper frame 4. Further, a well-known iron pin 8 is press-fitted into a groove formed in the upper frame 4 so as to face the peripheral surface of the rotor 3. The motor configured as described above is attached to the shutter base plate 1 by two screws 9 and 10. A moving magnet type motor having a configuration different from that of the motor of the present embodiment is described in Japanese Patent Application Laid-Open No. 2000-78808. The motor of the present invention may have such a configuration.

Next, the configuration inside the blade chamber will be described. On the surface of the shutter base plate 1 on the blade chamber side, two shafts 1c and 1d and two stoppers 1e and 1f are formed by integral molding. A pair of shutter blades 11 and 12 are rotatably mounted on the shafts 1c and 1d. As is well known, long holes are formed in the shutter blades 11 and 12, and the tip of the drive pin 3b is fitted into the long holes. Therefore, the shutter blades 11, 1
In FIG. 2, when the rotor 3 rotates in the counterclockwise direction in FIG. 1, the opening operation of the opening 1a is performed, and thereafter, when the rotor 3 rotates in the clockwise direction, the closing operation is performed. The opening regulating member 13 of this embodiment is not attached to the shutter base plate 1 but is attached to a member on the camera body side, and a part of the opening regulating member 13 moves within the operation locus of the arm 3c. I am getting it.

Next, the operation of the first embodiment having such a configuration will be described. FIG. 1 shows a closed state of the shutter. Therefore, the shutter blades 11 and 12 cover the opening 1a. At this time, the coil 6 of the stator is not energized. Therefore, the rotor 3 normally rotates due to the posture, vibration, and the like of the camera. However, the rotor 3 is located between the two due to the positional relationship of the iron pin 8 to the magnetic pole of the rotor 3. 3 is acting in a clockwise direction. Therefore, the shutter blade 1
1 and 12 receive the force to rotate in the closing operation direction, but the rotation is blocked by the stoppers 1e and 1f, and the initial position of the rotor 3, that is, the closed state in FIG. 1 is maintained. . It should be noted that the facing positional relationship between the magnetic poles of the rotor 3 and the iron pins 8 is not specifically described, but is disclosed in Japanese Patent Laid-Open No. 6-308.
As is well known in Japanese Patent Publication No. 570 and the like, the number of iron pins 8 is not limited to one as described in the publication. Further, in the state shown in FIG. 1, the opening regulating member 13
12 occupies a position operable until the opening 1a is fully opened.

In the state of FIG. 1, when the release button of the camera is pressed, the power switch is first closed, and the photometric device and the distance measuring device operate. Thereby, focusing of a photographic lens (not shown) is performed, and the position of the aperture regulating member 13 is automatically set in accordance with the condition of the subject. In the present embodiment, such a setting position of the opening regulating member 13 is one of four stages of a small opening regulating position, a middle opening regulating position, a large opening regulating position, and a fully opening regulating position. I can decide. However, in the present invention, such a position setting may be determined continuously, or may be performed in two or three stages corresponding to the distance of the subject. It can be done manually arbitrarily.

Therefore, a case will be described in which the opening regulating member 13 is set at the fully open regulating position and an image is taken. In that case, the opening regulating member 13 is not moved from the position shown in FIG. Then, a forward current is supplied to the coil 6. As a result, the rotor 3 is rotated in the counterclockwise direction, the shutter blades 11 and 12 are relatively rotated by the drive pin 3b, and the opening 1a is opened. afterwards,
Immediately after the shutter blades 11, 12 fully open the opening 1a, the rotor 3 is stopped by the arm 3c abutting on the opening regulating member 13. The stop state,
This is the state shown in FIG. Then, immediately or after a lapse of a predetermined time, when a current is supplied to the coil 6 in the reverse direction, the rotor 3 is rotated clockwise, and the drive pin 3b is rotated.
This causes the shutter blades 11, 12 to close the opening 1a. Then, the shutter blades 11 and 12 are
When a is closed and stopped by contacting the stoppers 1e and 1f, the current to the coil 6 is cut off, and the state returns to the state shown in FIG.

Next, when the opening regulating member 13 is set to any of the small opening regulating position, the middle opening regulating position, and the large opening regulating position, the opening regulating member 13 is moved from the position shown in FIG. , 4, 5, and 6. Therefore, needless to say, if a current is supplied to the coil 6 in the forward direction,
The opening operation of the shutter blades 11 and 12 is stopped in the states shown in FIGS. 4, 5 and 6, respectively. Thereafter, when the coil 6 is energized in the reverse direction, the state returns to the state shown in FIG. ,
Power supply to the coil 6 is cut off.

[Second Embodiment] Next, a second embodiment will be described with reference to FIGS. 7 and 8. The structure of the second embodiment is as follows.
This embodiment is different from the first embodiment in that a torsion coil spring 14 is provided. Therefore, substantially the same members and portions as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted, and only configurations different from those in the first embodiment will be described. The shutter base plate 1 of this embodiment is provided with a column 1g and a spring hook 1h on the surface facing the subject. FIG.
As can be seen from (a), the rotor 3 has a spring hook 3
d is formed. And the torsion coil spring 14
Is wound around the pillar 1g, and has one end hung on the spring hook 1h and the other end hung on the spring hook 3d of the rotor 3.

FIG. 7 shows a closed state of the shutter, which is a state before photographing is performed, as in FIG. 1 of the first embodiment. It has not been. However, in this state, the torsion coil spring 14 presses the drive pin 3b and urges the rotor 3 to rotate in the counterclockwise direction. However, the rotor 3 of the present embodiment is not rotated even if such an urging force is applied. that is,
This is because, as described in the first embodiment, the force acting between the rotor 3 and the iron pin 8 acts to rotate the rotor 3 clockwise. That is, the torsion coil spring 1
This is because the urging force of the coil 4 is weaker than the force acting to rotate the rotor 3 clockwise when the coil 6 is not energized.

However, it is not preferable to provide the torsion coil spring 14 in this manner from the viewpoint of maintaining the state of FIG. 7 reliably. Therefore,
Nevertheless, it will be explained why the present embodiment is provided with such a torsion coil spring 14.
As described above, the driving force of the moving magnet type motor is not so large. Therefore, the rise time of the shutter blade (the time required from the pinhole to the full opening)
Is not always obtained satisfactorily, and a desired short rise time cannot be obtained, or a predetermined rise time cannot be stably obtained, which may be disadvantageous in flash photography or the like. In particular, when the opening 1a is large, the size of the shutter blades is correspondingly large, so that the influence is likely to appear. In such a case, if the torsion coil spring 14 is provided as in this embodiment, the rise time can be suitably obtained. In this embodiment, the torsion coil spring 14 is provided for such a reason.

In this embodiment, the torsion coil spring 14 is provided for the above-mentioned reason, but the other structure is exactly the same as that of the first embodiment. That is, also in the present embodiment, the opening restricting member 13 can be set at four stages of opening restricting positions, and the shutter blades 11, 12 open and close the opening 1a by the reciprocating rotation of the rotor 3. It is supposed to. Therefore, the operation is performed in accordance with the first embodiment, and the description is omitted to avoid duplication.

In the above two embodiments, the arm 3c integral with the rotor 3 is provided with the notch 1 of the shutter base plate 1.
b is moved in the arm 3
This is because the provision of c prevents the overall size of the shutter in the optical axis direction from increasing. In the absence of such a restriction, the arm 3c is rather moved on the subject side of the shutter base plate 1. In general, the configuration is made so as to be able to be performed. In the case of such a configuration, in place of the cutout portion 1b, a long hole which is minimum necessary as a shutter having this kind of motor and which penetrates the drive pin 3b is used to operate the drive pin 3b. Since it is only necessary to form them in such a range, from the viewpoint of preventing light leakage, it is more advantageous than in the above embodiments.

In the above two embodiments, when the drive pin 3b is operated in the direction away from the opening 1a, the shutter blades 11 and 12 are configured to open. When the rotor 3 rotates clockwise with the position shown in FIG. 3 as an initial position,
That is, when the drive pin 3b operates toward the opening 1a,
The shutter blades 11 and 12 may be configured to perform the opening operation. In such a case, it is preferable that the arm 3c be operated on the subject side of the shutter base plate 1, as described above, so as not to complicate light leakage countermeasures.

[0026]

As described above, according to the present invention, a plurality of shutter blades are directly connected to a drive pin integral with a rotor made of a permanent magnet, and reciprocate in accordance with the direction of current supply to a stator coil. In the camera shutter in which the exposure opening is opened and closed, the arm provided near the root of the drive pin is directly brought into contact with the opening regulating member, and the opening is smaller than the full opening. Since it is possible to take a picture, the shape of the shutter blade is devised as in the conventional case in which the shutter blade directly contacts the opening restricting member, or a part of the opening restricting member is provided on the shutter base plate. There is an effect that the shutter can be compactly formed at low cost without forming a long hole for inserting the shutter.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment showing a closed state of a shutter.

FIG. 2A is a sectional view of a main part of the first embodiment,
FIG. 2B is a left side view of the rotor shown therein.

FIG. 3 is a plan view of the first embodiment showing a fully opened state of a shutter.

FIG. 4 is a plan view of the first embodiment showing a state in which the opening operation of the shutter blade is stopped at the small opening restriction position.

FIG. 5 is a plan view of the first embodiment showing a state in which the opening operation of the shutter blade is stopped at the middle opening restriction position.

FIG. 6 is a plan view of the first embodiment showing a state in which the opening operation of the shutter blade is stopped at the large opening restriction position.

FIG. 7 is a plan view of the second embodiment showing a closed state of the shutter.

FIG. 8A is a sectional view of a main part of a second embodiment,
FIG. 8B is a left side view of the rotor shown therein.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shutter base plate 1a, 2a Opening 1b Notch 1c, 1d shaft 1e, 1f Stopper 1g Column 1h, 3d Spring hook part 2 Auxiliary base plate 2b Groove 3 Rotor 3a Rotating shaft 3b Drive pin 3c Arm 4 Upper frame 4a Hook Part 5 Lower frame 6 Coil 7 Yoke 8 Iron pin 9, 10 Screw 11, 12 Shutter blade 13 Opening regulating member 14 Torsion coil spring

Claims (2)

[Claims] A drive pin having a rotor made of a permanent magnet which can reciprocate and rotate by a predetermined angle from an initial position in a direction corresponding to a direction of energization of a stator coil extends in parallel with the axis of rotation. A motor integrally provided at a radial position of the drive pin and having an arm protruding in a direction substantially perpendicular to the drive pin near the root of the drive pin, and connected to a distal end of the drive pin. A plurality of shutter blades that close the exposure opening when the rotor is at the initial position and relatively reciprocate in conjunction with the operation of the drive pin to open and close the exposure opening; An opening regulating member that stops the rotor that has been rotated from the initial position by inhibiting the operation of the arm, and allows the shutter blade to be stopped before the exposure opening is fully opened. Is characterized by Shutter for camera. 2. An apparatus according to claim 1, wherein one end of the torsion coil spring is hung on said drive pin to urge said rotor in a direction to open said shutter blade. The camera shutter according to any one of the preceding claims.