JPH0682878A - Shutter blade driving device - Google Patents

Abstract

PURPOSE:To stably keep the butting of a kicking lever against a projection provided on a shutter blade when it is driven in a kicking system. CONSTITUTION:A kicking lever 40 is held at a charging position by the restraining piece 18b of a restraining lever 18. A slope 40a is formed on the engaging part of the kicking lever 40 engaged with the engaging piece 18b. The slope 40a is narrowed in the upper part. The kicking lever 40 is pressed by a shutter driving spring 17 counterclockwise. The pressing force of the shutter driving spring is actuated downward by the engagement of the restraining piece 18b and the slope 40a, to shift the kicking lever 40 in a direction where it approaches the shutter blade.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutter blade drive device for driving a shutter blade in a kicking system.

[0002]

2. Description of the Related Art In a lens-fitted film unit in which a film is built in advance and a low-cost type compact camera, a kick-off type shutter blade driving device is used for saving the number of parts and simplifying the structure. Figure 5
Is an exploded view showing an example of a kick-off type shutter blade drive device incorporated in a film unit with a lens,
The shutter blades 2 are rotatably attached to a shaft 4 planted in a shutter base 3. A return spring 5 is hung between the shutter blade 2 and the shutter base 3, and the shutter blade 2 is urged toward a closed position that shields the exposure window 6. A shutter cover 22 covers the front surface of the shutter blade 2. Then, when the shutter blade 2 is in the closed position, the projection 7 integrally provided on the shutter blade 2 projects from the upper surface 22 a of the shutter cover 22. A photographing lens is held on the front surface of the shutter cover 22.

Three bosses 1 are formed on the upper surface of the shutter base 3.
0, 11, and 12 are integrally formed. On the boss 10, a kick-off lever 15 having a front end bent into an L shape and a counter disk 16 are rotatably attached to a shaft. A shutter drive spring 17 is fitted on the boss 11, and a locking lever 18
Is pivoted. A cam member 19 is inserted through the boss 12,
It is connected to the sprocket 20 inserted from behind. One end 17a of the shutter driving spring 17 is hooked on the hook 18a of the locking lever 18, and the other end 17b is kicked off.
5 is hung on the rear end 15a. As a result, the kick-out lever 15 is biased counterclockwise in the figure, and the locking lever 18 is biased clockwise.

When the film is fed by winding the film, the sprocket 20 rotates counterclockwise by the engagement with the perforation, and the cam member 19 rotates in the same direction. A one-tooth gear is formed on the upper end of the cam member 19, and this gear meshes with a gear provided on the outer circumference of the counter disc 16 to rotate the counter disc 16 by one scale. The cam follower 15b of the kick-off lever 15 is in sliding contact with the cam member 19, and the kick-off lever 15 rotates clockwise while charging the shutter drive spring 17 by the rotation of the cam member 19. When the kicking-out lever 15 rotates to the set position, the locking piece 18b provided on the locking lever 18 enters the right side of the engaging portion 15c of the kicking-out lever 15, and the kicking-out lever 15 is locked at the setting position.

When the shutter release operation is performed, the locking lever 18 is slightly rotated counterclockwise. As a result, the locking piece 18a is disengaged from the engaging portion 15c of the kick-off lever 15, and the kick-off lever 15 is rapidly rotated counterclockwise by the bias of the shutter drive spring 17. A kick-off arm 15d is integrated with the tip of the kick-off lever 15, and the kick-off arm 15d moves rightward along the upper surface 22a of the shutter cover 22. Then, the projection 7 protruding from the upper surface 22a of the shutter cover 22 is kicked off by the kicking arm 15d, and the shutter blade 2 rotates clockwise against the bias of the return spring 5 to open the exposure window 6. When the shutter blade 2 is rotated in the opening direction with the movement of the kicking arm 15d, the projection 7 moves below the upper surface 22a, and the shutter blade 2 returns to the return spring 5 while the kicking arm 15d moves to the release completion position.
It will return to its original closed position with the bias of. This completes one exposure operation.

In the above shutter blade drive device,
Since the shutter blade 2 is returned to the closed position in the state where the exposure is completed, the kicking arm 15d moves the shutter blade 2 in the process of moving the kicking arm 15 to the charging position.
It abuts the protrusion 7 and moves while overcoming this. At this time, since the shutter blade 2 is in contact with the stopper and stopped at the closed position, the kicking arm 15 and the arc-shaped outer edge 7a of the protrusion 7 are in strong sliding contact with each other, resulting in a large load when performing shutter charging. If the shutter blade 2 moves at this time, light leakage from the exposure window 6 may occur. For this reason, as shown in the figure, when the kicking arm 15d moves from the opposite direction, the projection 7
Is devised so as to bend and escape, or the structure of the shaft-attaching portion of the shutter blade 2 is improved so that the shutter blade itself escapes in a direction in which light does not leak.

[0007]

However, even if the above-mentioned measures are taken, if the projection 7 is made to escape by elasticity, the load at the time of shutter charging cannot be sufficiently reduced, In particular, as in the case of a lens-fitted photo film unit, in which the shutter charging force is obtained from the sprocket 20 meshing with the photo film perforation, the photo film perforation may be overloaded and may be broken. Further, if the shutter blades 2 are allowed to escape, the shutter blades 2 are likely to be adversely affected when the shutter blades are opened and closed, which is disadvantageous in maintaining stable exposure time. Therefore, the shaft attachment portion between the boss 10 and the kick-off lever 15 is provided with a vertical movement allowance (backlash), and when the kick-off lever 15d contacts the projection 7 in the process of moving the kick-off lever 15 in the charging direction, the kick-off lever 15d is kicked off. Lever 1
If 5 is allowed to escape upward, there is an advantage that the shutter charging operation is lightened without exerting unnecessary force on the shutter blade 2.

However, if the kick-off lever 15 is provided with vertical play due to the above-mentioned reasons, the trajectory of the kick-off arm 15d becomes unstable during shutter release, and the kick-off arm 15d is easily lifted from the upper surface 22a. The contact position with the protrusion 7 is likely to vary. As a result, the exposure may become non-uniform or, in extreme cases, the exposure window 6 may not be fully opened.

The present invention has been made in view of the above circumstances. Even when the kick-off lever is provided with a backlash in a direction away from the shutter blade, the shutter blade can be stably opened and closed during shutter release. An object is to provide a blade drive device.

[0010]

In order to achieve the above object, the present invention provides a kicking lever for driving a shutter blade from a closed position to an open position to a first position in a charged state by engaging with a locking lever. When locking, the kick-off lever is shifted so as to approach the shutter blades. Therefore, an inclined surface is formed in the engaging portion of the kick-off lever that engages with the locking lever, and the inclined surface receives the biasing force of the shutter drive spring that biases the kick-off lever, and the component force is utilized. The kicking lever is shifted toward the shutter blade.

[0011]

EXAMPLE FIG. 4 shows a disassembled state of a lens-fitted film unit according to the present invention. This lens-fitted photo film unit has a unit main body 25, a front cover 26 and a rear cover 27 covering the front and rear of the unit main body 25, and is constructed by covering the outer surface of the unit main body 25 with a paper box provided with a cosmetic print. A cartridge chamber 30 and a film chamber 31 are integrally formed in the unit main body 25, and a cartridge 32 and a roll-shaped film 33 are housed therein. On the front surface of the unit body 27, a shutter blade drive device 35 to which the present invention is applied is further incorporated. Note that, in the following description, the members constituting the shutter blade driving device 35 and the peripheral members thereof that are common to those shown in FIG.

A shutter cover 22 holding a taking lens 36 is mounted on the front surface of the shutter blade driving device 35,
Further, a front cover 26 is attached so as to cover the front surface thereof. A shutter button 37 is integrally formed on the upper surface of the front cover 26, and the shutter release can be performed by rotating the locking lever 18 counterclockwise by pushing down the shutter button 37.

FIG. 1 shows the external appearance of the shutter blade drive device 35 in the charged state. In this shutter blade drive device 35, a kick-off lever 40 is incorporated in the boss 10 with a play of about 0.5 to 1.0 mm in the vertical direction. The kick-off lever 40 used in the shutter blade driving device 35 has the same basic shape as the kick-off lever 15 described above, but as shown in the enlarged view of FIG. The slanted surface 40a is formed in the portion that engages with the locking piece 18b in the locked state, and the slanted surface 40b is also formed on the front surface side thereof, and both of these slanted surfaces 40a and 40b are narrowed upward. ing.

When the shutter is released, the kick-off lever 40 is rotated counterclockwise by the urging force of the shutter drive spring 17, and the kick-out arm 42 provided integrally with the kick-off lever 40 is shown by a solid line in FIG. Move from the charge position to the release completion position shown by the chain double-dashed line. During the movement, the projection 7 projecting from the upper surface 22a of the shutter cover 22 is kicked to open and close the shutter blade 2. After taking a picture, when the film winding dial 43 shown in FIG. 4 is rotated counterclockwise, the film 33 is fed, whereby the sprocket 20 is rotated. After that, the kick-off lever 40 moves to the charging position by operating in exactly the same manner as the shutter blade driving device of FIG. 5, and is held at that position by the locking piece 18b of the locking lever 18.

The operation of the shutter blade drive device 35 will be described. When the kick-off lever 40 moves to the charging position and is locked by the locking piece 18b of the locking lever 18,
As shown in FIG. 3A, the tip of the locking piece 18 has a slope 40.
engage a. Note that FIG. 3A shows an arrow A in FIG.
It shows a state of the engaging portion when viewed from the direction. Since the kick-off lever 40 is biased rightward in the figure by the shutter drive spring 17, a downward biasing force is applied to the kick-off lever 40 by the contact between the locking piece 18b and the slope 40a. Therefore, the kick-off lever 40 shifts downward and approaches the shutter blades 2 even if the kick-off lever 40 is fitted in the boss 10 in a loose state, and the kick-off arm 42 comes into contact with the upper surface 22 a of the shutter cover 22.

In this way, the kicking arm 42 is attached to the upper surface 2
By shifting so as to be in contact with 2a, even if the kicking lever 40 is provided with backlash in the vertical direction, the start position when kicking the projection 7 of the shutter blade 2 by the kicking arm 42 can be always kept constant. Therefore, it is possible to eliminate the inconvenience that the kicking-out arm 42 starts from the charging position lifted from the upper surface 22a and moves to the release completion position without contacting the protrusion 7.

When the shutter button 37 is pressed to perform the shutter release, the locking lever 18 rotates counterclockwise, and the locking piece 18b moves in the direction opposite to the arrow A direction in FIG. Then, at the moment when the engaging piece 18b is disengaged from the slope 40a, the kicking lever 40 is rotated counterclockwise by the bias of the shutter drive spring 17. FIG. 3B shows the locking piece 18
The state at the moment when b comes off the slope 40a is indicated by the arrow B in FIG.
It is shown as viewed from the direction.

When the locking piece 18b is disengaged from the slope 40a and the kicking arm 40 begins to rotate counterclockwise, the locking piece 1
A slope 40b is in sliding contact with the tip of 8b. At this time, even if the kick-out lever 40 tries to move upward due to backlash, the tip of the locking piece 18b comes into contact with the inclined surface 40b and suppresses its rise. Therefore, the kicking arm 42 does not float up immediately after the movement thereof is started, and the projection 7 of the shutter blade 2 is always kicked under a constant condition, and the exposure time can be more accurately maintained.

After filming, the film winding dial 4
When 3 is rotated counterclockwise, the film is fed.
The sprocket 30 rotates by feeding the film 33,
In conjunction with this, the kick-off lever 40 is returned from the release completion position to the charge position. As a result, the kicking arm 42 moves from the two-dot chain line position in FIG. 1 to the solid line position. Then, in the middle of the movement, the protrusion 7 is pressed from the right side to rotate the shutter blade 2 in the counterclockwise direction, but since the shutter blade 2 is in the closed position in contact with the stopper (not shown), The shutter blade 2 maintains the same position. Therefore, the kick-out arm 42 receives an upward force by the arc-shaped outer edge 7 a of the protrusion 7.

As described above, the kick-off lever 4
Since 0 is pivotally attached to the boss 10 with some play in the vertical direction, when the upward force is applied to the kicking arm 42 as described above, the kicking arm 40 moves upward. Therefore, when the kick-off lever 40 is returned to the charging position, the protrusion 7 is simply bent downward,
Alternatively, the load applied to the kick-off lever 40 can be reduced, and the shutter charging operation can be lightened, as compared with a case where the kick-off arm 42 itself is bent upward. Of course, at this time, the force applied to the shutter blade 2 can be reduced, so that it is possible to eliminate the inconvenience of the shutter blade 2 moving carelessly and leaking light from the exposure window 6.

Although the present invention has been described above with reference to the illustrated embodiment, the present invention is not limited to the shutter blade driving device incorporated in the lens-fitted film unit, but is also a kick blade type shutter blade driving device such as a simple compact camera. If it uses, it is equally applicable. In FIG. 2, even if the locking piece 18b moves above the slope 40a to unlock the kicking lever 40, the kicking lever 40 is shifted to the shutter blade 2 side by the slope 40a at the charging position. Therefore, it is effective to stabilize the start position of the kicking arm 42 to stabilize the contact with the protrusion 7.

[0022]

As described above, according to the present invention, when the kicking lever is held at the charging position by the engagement with the locking lever, the engaging portion of the kicking lever is formed with a bevel, and the kicking lever is formed. Since the kicking lever is shifted to the shutter blade side by using the biasing force of the shutter drive spring that biases the kicking lever, the charge position of the kicking lever can be kept constant even if the kicking lever has some play. Therefore, it is possible to stabilize the contact between the kick-off lever and the projection of the shutter blade, prevent uneven exposure, and obtain an appropriate exposure time.

[Brief description of drawings]

FIG. 1 is an external view of a shutter blade driving device using the present invention.

FIG. 2 is an external view of a kick-off lever using the present invention.

FIG. 3 is an explanatory diagram showing a state of engagement between a kicking lever and a locking piece.

FIG. 4 is an exploded view of a film unit with a lens incorporating the device of the present invention.

FIG. 5 is an exploded view of a conventional shutter blade drive device.

[Explanation of symbols]

 2 Shutter blade 5 Return spring 7 Protrusions 15 and 40 Kicking levers 15d and 42 Kicking arm 17 Shutter drive spring 18 Locking lever 18b Locking pieces 40a and 40b Slope

Claims (1)

[Claims] 1. A shutter blade that is movable between a closed position and an open position and is spring-biased toward the closed position; and a shutter drive spring biases a shutter blade from a first position to a second position.
Of the shutter blades, the projections provided integrally with the shutter blades are kicked in the middle of this displacement to move the shutter blades to the open position against the spring bias, and then the projections are engaged. Release lever to allow the shutter blades to return to the closed position by the biasing of the spring, and the kicking lever is interlocked with the shutter charge operation to resist the bias of the shutter drive spring to the second position. To the first position by engaging the shutter charge mechanism that returns the shutter charging mechanism to the first position, resisting the bias of the shutter drive spring and locking the shutter driving spring at the first position, and releasing the engagement by the shutter release operation. By providing an engaging lever of the kicking lever engaging with the engaging lever, a slope is formed, and the biasing force from the shutter drive spring is received by the slope, The shutter blade drive device, characterized in that to lock the fly lever to the first position is shifted so as to approach the shutter blade.