JPH10148869A - Camera shutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera shutter capable of suppressing shutter blades from bounding and capable of miniaturization. SOLUTION: The shutter blades 4 and 5 are arranged between a shutter base plate 1 and an auxiliary base plate 2 whose outside diameter is nearly the same as that of the base plate 1. An opening/closing member 14 is moved back and forth cooperatively with a driving pin 13 which is integrally formed with the rotor 12 of a motor, and at a shutter opening operation, the member 14 is driven by a coil spring 15, at the shutter closing operation, the member 14 is driven by the motor. The shutter blades 4 and 5 are opened/closed by the operating pin 14c of the opening/closing member 14, and at the final stage of the opening operation, parts to be checked 4d and 5d are engaged with checking parts 1k and 1i installed on the shutter base plate 1, and at the final stage of the closing operation, parts to be checked 4c and 5c are engaged with checking parts 1h and 1j installed on the shutter base plate 1, then, the shutter blades 4 and 5 are stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera shutter of a type generally called a lens shutter.

[0002]

2. Description of the Related Art A lens shutter has been required to be miniaturized with the miniaturization of a camera, especially with a reduction in a lens aperture. However, recently, with the advent of an IX240 cartridge film, it has been further spurred. I have. One of the major points when downsizing the lens shutter is
This is how to reduce the space accommodating the shutter blades when the shutter is fully opened. Also,
Another point is how to suppress the bouncing that occurs when fully open and closed. That is, in order to prevent the shutter blades from entering the exposure opening even when the shutter blades are fully opened, a space larger than the above-described storage space is required. In order to prevent the opening of the exposure opening from opening, the operating area after the closing has to be greatly increased.

[0003] By the way, many mechanisms for preventing such a bounce have been proposed and implemented so far. As a typical example thereof, two shutter blades are used, and when the shutter is fully opened, There is one in which only one shutter blade is brought into contact with a stopper. The details of the mechanism are as follows. The two shutter blades are each pivotally supported by a shutter base plate, and pins of the opening and closing members are fitted into slots (elongated holes) formed in each shutter blade. Therefore, when the opening and closing members reciprocate, the shutter blades relatively operate to open and close the exposure opening. When one of the shutter blades comes into contact with the stopper at the time of full opening, the blade bounces and attempts to operate in the closing direction. However, since the other shutter blade does not come into contact with the stopper, the shutter blade continues to operate in the same direction as before even after fully opened. As a result, opposing forces of the two shutter blades act on the pins of the opening / closing member, and these are canceled out to suppress bouncing.

[0004]

However, even if the above-described bounce prevention mechanism is employed, the fitting between the pin of the opening / closing member and the slot of each shutter blade is set to a tolerance, so that it is completely bound. Is not eliminated, but only the bounce is small and the time during which the bounce occurs is shortened. On the other hand, recently, ISO 160
High-sensitivity films such as 0 have come to be used favorably. Therefore, it is necessary to operate the shutter blades at high speed, but in that case, it is no longer possible to cope with the above mechanism alone, the bounce cannot be sufficiently suppressed, and the closing operation is started during the bounce. In some cases, the shutter speed has to be adjusted, which causes a problem that the shutter speed cannot be stably obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object thereof is to open and close an exposure opening by reciprocating a plurality of shutter blades. In the lens shutter, at least one shutter blade is provided with a suppression means, and at least one of the end of the opening operation and the end of the closing operation of the shutter blade, the suppression means engaging with the suppression means is provided. An object of the present invention is to provide a camera shutter in which the operation of the shutter blades can be suitably stopped by being provided on the main plate.

[0006]

In order to achieve the above object, a camera shutter according to the present invention has an opening for allowing subject light to pass therethrough, and is arranged with a predetermined space therebetween. Two base plates, an opening / closing member that is reciprocated by a drive source at the time of exposure, and a plurality of sheets that are arranged between the two base plates and reciprocate in conjunction with the reciprocating operation of the opening / closing member to open and close the opening, and And at least one of the shutter blades provided with the restrained means and the restraining means engaged with the restrained means at least at one of the end of the opening operation and the end of the closing operation of the shutter blade. It is provided on at least one of the two ground plates. In the camera shutter according to the present invention, preferably, the shutter blades include two shutter blades, and at least one of the shutter blades is brought into contact with the stopper at the end of at least one of the opening operation and the closing operation. At least one of the two ground plates is provided.

Further, in the camera shutter according to the present invention, preferably, the restraining means has elasticity. In the camera shutter according to the present invention, it is preferable that a driving source for one of the reciprocating operations of the opening / closing member is a motor and a driving source for the other operation is a spring. In the camera shutter according to the present invention, preferably, a driving source for reciprocating operation of the opening / closing member is a motor. Further, in the camera shutter according to the present invention, preferably, the motor is a moving magnet type motor, and the opening / closing member is integrally formed with a rotor of the moving magnet type motor.

[0008]

1 to 3 show an embodiment of the present invention.
1 and the second embodiment shown in FIG. FIG. 1 is a plan view showing an initial state of the first embodiment, that is, a state before the release of the camera, and is drawn in perspective. FIG. 2 is a cross-sectional view showing the open / close mechanism in the first embodiment in an expanded state for easy understanding.
FIG. 3 is a plan view showing the fully opened state of the shutter blades in the first embodiment, and is drawn in a transparent manner as in FIG. Further, FIG. 4 is a plan view showing an initial state of the second embodiment, and is drawn in a transparent manner as in FIG.

First, the configuration of the first embodiment will be described. The shutter base plate 1 in the present embodiment is made of a synthetic resin,
A circular opening 1a for exposure is formed at the center to allow subject light to pass. In FIG. 1, on the back side of the shutter base plate 1, an auxiliary base plate 2 having substantially the same outer diameter is arranged, attached to the shutter base plate 1 with three screws 3, and between the base plates 1 and 2. A blade chamber is formed. Shutter blades 4 and 5 are arranged in the blade chamber, and are pivotally supported by shaft portions 1b and 1c provided on the shutter base plate 1, respectively. The auxiliary base plate 2 is also made of synthetic resin, and has an opening substantially the same as the above-described opening 1a in the center portion.
An exposure opening is constituted by these two openings. Although not shown, the shutter base plate 1 is provided with an attachment portion to the camera body, and is attached to the camera such that the shutter base plate 1 is on the lens side and the auxiliary base plate 2 is on the film side. It has become.

As can be clearly understood from FIG. 2, a motor lower frame 6 made of a synthetic resin is attached to the front side of the shutter base plate 1, ie, the lens side, by two screws 7. Similarly, the upper frame 8 made of synthetic resin has a cylindrical shape, and a cylindrical yoke 9 is fitted on the outer peripheral surface thereof. And
A rod-shaped magnetic member 10 is embedded in the upper frame 8. Further, the lower frame 6 and the upper frame 8 are wound like a peg and the coil 1
1 is wound. Further, a rotor 12 rotatably supported by the lower frame 6 and the upper frame 8 is disposed in a space formed by the lower frame 6 and the upper frame 8. The rotor 12 is made of a permanent magnet, and its rotating shaft is made of a synthetic resin.

A motor having such a configuration is called a moving magnet type motor, and is well known as a motor for operating shutter blades and aperture blades.
When power is supplied to the motor, the motor rotates in a forward or reverse direction by a predetermined angle according to the direction of power supply. In this motor, a drive pin 13 is formed integrally with the rotating shaft as an output part. However, in FIGS. 1 and 3, the drawings become difficult to see, so that the rotor 12 and the drive pin 13 are unavoidable. Are shown separately. And, this drive pin 13
Are inserted into an arc-shaped hole 1d formed in the shutter base plate 1.

On the other hand, a shaft 1 provided on the shutter base plate 1
As shown in FIG. 2, e supports the lower frame 6 at its distal end, and an opening / closing member 14 is rotatably attached thereto. A coil spring 15 is wound around a shaft portion of the opening / closing member 14, and one end thereof is hung on a spring hook 14 a of the opening / closing member 14, and the other end is hung on a spring hook 1 f provided on the shutter base plate 1. Therefore, the opening / closing member 14
1 is urged clockwise in FIG. 1 by the coil spring 15, so that the arm 14 b contacts the drive pin 13. The opening / closing member 14 is provided with an operating pin 14c, which penetrates through an arc-shaped hole 1g formed in the shutter base plate 1 and fits into slots (long holes) 4a, 5a of the shutter blades 4, 5. doing.

The two ground plates 1 and 2 are provided with a plurality of projections which engage with the shutter blades 4 and 5 toward the blade chamber formed therebetween. First, the auxiliary base plate 2
Stoppers 2a and 2b are provided, and can come into contact with overhangs 4b and 5b formed on shutter blades 4 and 5, respectively. On the other hand, the shutter base plate 1 is provided with four cylindrical suppressing portions 1h, 1i, 1j, 1k, and the suppressed portions 4c, 4d, 4c, 4d, formed as arc-shaped concave portions on the shutter blades 4, 5, respectively. 5c and 5d, respectively.

Next, the operation of this embodiment will be described. FIG.
Indicates a state before the camera is released, and the coil 12 of the motor is not energized. However, the rotor 12
Is a permanent magnet, a magnetic force acts between the magnetic member 10 embedded in the upper frame 8 and thereby,
The opening and closing member 14 is maintained at the initial position in FIG. 1 against the urging force of the coil spring 15. At this time, the projecting portions 4b and 5b of the shutter blades 4 and 5 come into contact with the stoppers 2a and 2b, and the suppressed portions 4c and 5c become the suppressing portions 1c.
h, 1j. Therefore, the shutter blades 4,
Reference numeral 5 ensures that the closed state is maintained by the above-mentioned magnetic force and the engagement friction, and the camera 5 is not opened by the vibration of the camera.

When the release button of the camera is depressed in such a state, the photometry circuit operates first in the initial stage, and thereafter the coil 11 is energized in the forward direction. Thereby, the rotor 12 is rotated counterclockwise in FIG. 1, and the driving pins 13 are also rotated counterclockwise. Accordingly, the opening / closing member 14 is rotated clockwise by the urging force of the coil spring 15, and the operating pin 14c causes the shutter blade 4 to rotate counterclockwise in the shaft 1b and the shutter blade 5 to rotate clockwise in the shaft 1c. Rotate. In this case, since the shutter blades 4 and 5 are thin plates and have flexibility, the shutter blades 4 and 5 slightly bend at the start of the opening operation, and the restrained portions 4c and 5c come off the restraining portions 1h and 1j. After that, the shutter blades 4, 5
The opening 1a is opened at a high speed.

When the shutter blades 4 and 5 are about to finish opening the opening 1a in this way, the advancing ends of the blades 4 and 5 are slid into contact with the restraining portions 1k and 1i and are pressed so as to be slightly bent. As a result, braking is performed, and finally, the inhibited portions 4d and 5d engage with the inhibiting portions 1k and 1i and stop. FIG. 3 shows a state in which the opening 1a is stopped in this way and the opening 1a is fully opened. Therefore, in the present embodiment, the shutter blades 4 and 5 stop without bouncing, so that the distance between the edge of the opening 1a and the edge of the shutter blades 4 and 5 can be set to a minimum, and space can be reduced. It becomes suitable.

If the opening operation of the shutter blades 4 and 5 is extremely fast, there is a possibility that the shutter blades 4 and 5 may overrun beyond the engagement position with the restraining portions 1k and 1i. Therefore, when there is such a concern, each blade 4,
A part of the advancing end of No. 5 may be brought into contact with the stopper. In this case, the reversing force is reduced due to the flexibility of the shutter blades 4 and 5, so that the shutter blades 4 and 5 can be stopped without bouncing until the engagement state is released. In that case, it should be understood from the above description of the conventional example that it is effective to provide the stopper only for one of the blades.

Next, after such a full opening, when a predetermined time elapses based on the photometry result, the coil 11 is energized in the reverse direction. Thereby, the rotor 12 is rotated clockwise in FIG. Therefore, the drive pin 13 also rotates clockwise, and the shutter blade 4 rotates clockwise, and the shutter blade 5 rotates counterclockwise to close the opening 1a. At the start time of the closing operation, the engagement between the inhibited portions 4d, 5d and the inhibiting portions 1k, 1i is released in the same manner as the start timing of the opening operation. When the closing operation comes to an end stage, the overhanging portions 4b, 5b of the blades 4, 5 are slidably contacted with the restraining portions 1h, 1j, pushed to bend slightly and braked, and thereafter, the restrained portions 4c, 5c. Are engaged with the restraining portions 1h and 1j, and almost simultaneously, the overhang portions 4b and 5b abut against the stoppers 2a and 2b and stop.

The state in which the closing operation of the shutter blades 4 and 5 is stopped is as shown in FIG. 1. Thereafter, the energization of the coil 11 is stopped, and a series of exposure operations is completed. In the present embodiment, the bounce at the time of the closing operation is appropriately suppressed in this manner, so that the degree of overlap of the shutter blades 5 and 6 in the closed state is determined by considering only the light leakage without considering the bounce. It becomes possible. In addition, if the stoppers 2a and 2b are provided or only one of them is provided, it may be selected at the time of design according to the case described in the description of the opening operation.

Next, a second embodiment of the present invention will be described with reference to FIG. The configuration of this embodiment is almost the same as the configuration of the first embodiment. Therefore, the same components and parts are denoted by the same reference numerals, and description thereof will be omitted. Only different points will be described. FIG. 4 is a plan view transparently showing the initial state of the camera before the release, similarly to FIG. 1 in the first embodiment. In FIG. 4, a part of the shutter blades 4 and 5 in the fully opened state is shown by a chain line.

The configuration of this embodiment is different from that of the first embodiment in that, in the first embodiment, the inhibiting means of the present invention is shown as inhibiting sections 1h, 1i, 1j, and 1k. This is what is shown as two restraining springs 16 and 17 in the present embodiment. These restraining springs 16, 17
Is a leaf spring, and three shaft parts 1m, 1n, 1p and three shaft parts 1q, 1 provided on the shutter base plate 1, respectively.
r, 1s, each having at its both ends suppression portions 16a, 16b and suppression portions 17a, 17b bent in an arc shape. As can be seen from this configuration, the suppression units 16a, 16b, 17a, and 17b in the present embodiment are arranged at the same positions as the suppression units 1h, 1i, 1j, and 1k in the first embodiment, and are provided on the shutter blades, respectively. Suppressed part 4
c, 5d, 5c, and 4d.

In this embodiment, the opening and closing operation is almost the same as that of the first embodiment because of such a structure. Therefore, although the description is omitted, the feature of the present embodiment is that the suppression units 16a, 16b, 17a, and 17b are not fixed,
That is, the elasticity of the restraining springs 16 and 17 enables the restraining springs 16 and 17 to move slightly. Therefore, each of the shutter blades 4 and 5 is provided with a corresponding one of the suppression units 16a, 17b, 17a, and 16a.
In sliding contact with b, the restraining springs 16 and 17 bend, so that the amount of bending of the shutter blades 4 and 5 can be eliminated or reduced, and the shutter blades 4 and 5 are restrained by the restraining portions 16a, 17b and 17b. When the shutter blades 17a and 16b are hit, the shocks are absorbed and reduced, and the operation of the shutter blades 4 and 5 is stably performed.

In each of the above embodiments, the deterrent unit 1
h, 1i, 1j, 1k, 16a, 16b, 17a, 17
Although b is formed in a convex shape and the suppressed portions 4c, 4d, 5c, and 5d are formed in a concave shape, they may be formed so that their shapes are reversed, or only some of them are reversed. It may be formed so that In the first embodiment,
Although the suppressing portions 1h, 1i, 1j, 1k are provided on the shutter base plate 1, a part or all of them may be provided on the auxiliary base plate 2. Further, from such a concept, the shutter blade 4 has a spherical protruding portion formed on the surface thereof toward the shutter base plate 1 side, which is used as a suppressed portion, and a spherical protruding portion formed on the shutter base plate 1 side. The concave portion may be formed and used as the suppressing portion. When such a configuration is also adopted for the shutter blade 5, a suppressed portion is formed toward the auxiliary base plate 2, and a suppression portion is formed on the auxiliary base plate 2.

In the second embodiment, the restraining springs 16 and 17 are formed as independent members. However, the restraining portions 16a, 16b, 17a and 17b which are movable by elasticity.
May be integrally formed on at least one of the two ground plates 1 and 2 with a synthetic resin. Further, in each of the above-described embodiments, two suppressed portions are provided on each shutter blade, but the present invention is not limited to such. That is, the mechanism of the present invention in which the bounce is substantially eliminated may be employed only for the opening operation of the shutter blade, for example. Further, for the same reason as described for the stoppers 2a and 2b in the description of the first embodiment, only one of the shutter blades may be employed. Further, the present invention is not limited to a lens shutter having two shutter blades as in each embodiment, but is also applicable to a well-known lens shutter in which each blade is divided into four shutter blades to reduce the size. It is possible to

Furthermore, in each of the above embodiments, a spring is used as a driving source for the opening operation, and a motor is used as a driving source for the closing operation. However, the present invention is not limited to such. Instead, both may be driven by a spring or a motor, or the opening operation is performed by a motor,
The closing operation may be performed by a spring. In each of the above embodiments, the operating pin 14 of the opening / closing member 14 is used.
Although c is fitted into the slots 4a, 5a of the shutter blades 4, 5, such an opening / closing member 14 may be omitted, and the drive pin 13 may be fitted directly into the slots 4a, 5a. Absent. In that case, the opening and closing member in the present invention is not the opening and closing member 14 but the drive pin 13. However, in each of the above embodiments, when such a configuration is employed, the drive pin 13 is rotated clockwise during the opening operation, or the shutter blades 4, 5
It is necessary to adopt a pivotally mounted configuration in which the operating directions of are reversed, but such a configuration is well known and a detailed description thereof will be omitted.

[0026]

As described above, according to the present invention, the suppressed portion is provided on the shutter blade and the restraining portion is provided on at least one of the shutter base plate and the auxiliary base plate, so that the bounce of the shutter blade can be suppressed. The size of the shutter can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view perspectively showing a first embodiment of the present invention, showing a state before a camera is released.

FIG. 2 is a sectional view showing the configuration of the opening / closing mechanism shown in FIG. 1 in an expanded state.

FIG. 3 is a plan view perspectively showing the first embodiment,
The fully opened state of the shutter blade is shown.

FIG. 4 is a plan view showing a perspective view of a second embodiment of the present invention, showing a state before the camera is released.

[Explanation of symbols]

1 shutter base plate 1a opening 1b, 1c, 1e, 1m, 1n, 1p, 1q, 1r, 1
s Shaft 1d, 1g Hole 1f, 14a Spring hook 1h, 1i, 1j, 1k, 16a, 16b, 17a, 1
7b Suppression part 2 Auxiliary base plate 2a, 2b Stopper 3,7 Screw 4,5 Shutter blade 4a, 5a Slot 4b, 5b Overhang part 4c, 4d, 5c, 5d Suppression part 6 Lower frame 8 Upper frame 9 Yoke 10 Magnetic body Member 11 Coil 12 Rotor 13 Drive pin 14 Opening / closing member 14b Arm 14c Actuating pin 15 Coil spring 16, 17 Suppression spring

Claims (6)

[Claims] 1. An opening / closing member which has an opening for allowing subject light to pass therethrough and is disposed at a predetermined interval between them, an opening / closing member which is reciprocated by a driving source at the time of exposure, and A plurality of shutter blades arranged between two base plates, reciprocatingly interlocking with the reciprocating operation of the opening and closing member to open and close the opening, and at least one of the shutter blades provided with a restraining means; A shutter for a camera, wherein at least one of the two base plates is provided with a restraining means to be engaged with the restrained means at least at the end of the opening operation of the blade and at the end of the closing operation of the blade. 2. A shutter having two shutter blades, wherein at least one of the shutter blades is provided with a stopper on at least one of the two base plates at the end of at least one of the opening operation and the closing operation. The camera shutter according to claim 1, wherein: 3. The camera shutter according to claim 1, wherein said restraining means has elasticity. 4. The driving source for one of the reciprocating operations of the opening / closing member is a motor, and the driving source for the other operation is a spring. Camera shutter. 5. The camera shutter according to claim 1, wherein a driving source for reciprocating the opening and closing member is a motor. 6. The camera shutter according to claim 5, wherein the motor is a moving magnet type motor, and the opening / closing member is integrally formed with a rotor of the moving magnet type motor. .