JP2714504B2 - Shutter mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutter mechanism for exposing a photographic film by opening and closing shutter blades. More specifically, the present invention relates to light shielding of an exposure opening when shutter blades are closed.

[0002]

2. Description of the Related Art As disclosed in Japanese Patent Publication No. 2-32615, a simple photographing mechanism is incorporated in a container for storing a film, as disclosed in Japanese Patent Publication No. 2-32615. Film unit with lens (hereinafter referred to as film unit)
Are commercially available. This film unit is designed so that it can be easily purchased and photographed at a store even when the user does not normally carry a camera, and is compact and inexpensive. The film unit has a simple shutter mechanism, and a shutter base having an exposure opening is provided with one shutter blade rotatable around an axis. The shutter blade is urged by a spring in a blade closing direction, and is opened and closed by a shutter drive lever kicking a claw at an end of the shutter blade.

[0003]

However, in order to drive the shutter blades smoothly, it is not possible to provide a structure in which the shutter blades and the shutter base are in close contact with each other. There is a possibility that external light may enter through the gap between the shutter blades and the shutter base and reach the film through the exposure opening, causing light leakage. The present invention has been made to solve the above problems, and it is an object of the present invention to enhance the light shielding property between a shutter blade and an exposure opening provided in a shutter base without impairing smooth driving of the shutter blade. I do.

[0004]

According to the present invention, in order to achieve the above-mentioned object, a light-shielding property is enhanced by providing a ridge on a shutter base and a shutter blade and combining them. Further, a plastic-molded shutter blade is used in order to easily form a ridge on the shutter blade and to perform smooth driving.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 illustrates the appearance of the film unit 1 embodying the present invention. The film unit 1 is obtained by covering a unit body 2 mainly made of plastic with a paper box 3 whose surface is subjected to resin processing. On its front face, a photographing lens 4 and a finder opening 5 are provided, a shutter button 6 and a display window 7 for displaying the number of remaining films.
Is disposed on the upper surface. Behind the film unit 1 is exposed a part of a winding knob 8 for charging the shutter simultaneously with winding the film.

FIG. 1 shows a state where the paper box 3 is peeled off and the unit body 2 is disassembled. Unit body 2
A main body 13 having a film roll chamber 10 for accommodating a film roll 9a in which an unexposed film 9 is wound into a roll, a patrone chamber 12 for accommodating a patrone 11 for winding a photographed film 9, and a rear cover. 14 and a front cover 15. A fork member integrally formed with the hoisting knob 8 is inserted from above the patrone chamber 12 of the main body 2 and engages with a spool 16 rotatably housed in the patrone 11. The film 9 whose end is fixed to the spool 16 and pulled out of the cartridge 11 is supported by the exposure frame from the back by the film regulating surface 17 of the rear cover 14.

On the front surface of the main body 13, a shutter mechanism 18 for exposing the film 9 stretched to the exposure frame is provided. In FIG. 2 showing the shutter mechanism 18, the locking lever 20 and the shutter driving lever 21 are attached to the main body 13 by screws 22 and 23 so as to be rotatable around the axis. When the film 9 is wound up by one frame, the sprocket 19 engaged with the perforation of the film 9 makes one rotation, and at the same time, the cam 24 fitted on the upper part rotates. The rotation of the cam 24 rotates the shutter drive lever 21 to the start position and is locked by the locking lever 20. At this time, the locking lever 20
The rotation of the cam 24 and the winding knob 8 is also restricted. A number display plate 25 is provided above the shutter drive lever 21, and engages with the cam 24 to rotate by one tooth with one rotation of the cam 24.

A shutter base 28 provided with an exposure window 26 has plastic shutter blades 28 rotatably mounted on a shaft 27a. A ridge 29 is formed in a rectangular shape along the periphery of the exposure window 26, and a guide ridge 29 a extends from a lower left corner thereof along a rotation circumference of the shutter blade 28. A stopper 30 is formed on the right side of the ridge 29 so as to wrap the tip of the shutter blade 28. The shutter blade 28
It is urged in the closing direction by a spring 31 stretched between a spring mounting protrusion 28a provided on the left side of the shaft 27a and a spring stopper 32 provided on the shutter base 27. A claw 28b is provided at the upper end of the shutter blade 28, protrudes from between the shutter cover 33 and the shutter base 27, and is rotated clockwise by the arm 21a of the shutter drive lever 21 when the shutter is released.

Further, on the surface of the shutter blade 28 facing the shutter base 27, a ridge 28c is integrally formed as shown by a broken line in FIG. Therefore, when the shutter blade 28 is in the closed position, the ridge 29 of the shutter base 27 and the ridge 2 of the shutter blade 28 as shown in FIG.
8c, the light does not leak from the gap between the shutter blade 28 and the shutter base 27 to the film 9 through the exposure window 26. A shutter cover 33 having a lens holder 34 covers the shutter blade 28 attached to the shutter base 27 in this manner. The lens 4 in the lens holder 34 of the shutter cover 33
The exposure aperture 35 is opened at the position of the optical axis of the lens 9 and the subject image is exposed on the film 9 through the lens 4, the exposure aperture 35 and the exposure window 26 at the time of shutter release.

The operation of the thus configured film unit 1 will be described. At the time of photographing, first, the wind-up knob 8 is operated to charge the shutter. When the winding knob 8 is rotated, the spool 16 rotates in the film winding direction via a fork member integrally formed therewith. As the film 9 is transported, the sprocket 19 engaged with the perforation of the film 9 rotates counterclockwise, and at the same time, the cam 2 fitted on the upper part.
4 also rotates in the same direction. Accordingly, the shutter driving lever 21 that is in contact with the cam 24 by the spring bias rotates counterclockwise, moves to the cocking position by one rotation of the cam 24, and is locked by the locking lever 20. When the shutter charging is completed, the rotation of the winding knob 8 is also restricted by the locking lever 20, and the photographer can confirm that the shutter charging is completed.

When the subject is framed through the finder opening 5 and the shutter button 6 is pressed, the locking of the locking lever 20 is released, and the shutter driving lever 21 rapidly rotates counterclockwise. With this rotation, the arm 21a of the shutter drive lever 21 kicks the claw 28b of the shutter blade 28 in the X direction in FIG. 4, and the shutter blade 28 turns in the Y direction against the bias of the spring 31. At the time of rotation, a portion where the protrusion 28c of the shutter blade 28 overlaps the guide protrusion 29a provided on the shutter base 27 is cut out, and the guide protrusion 29a is provided on the rotation circumference. Therefore, smooth rotation is not hindered.

When it is rotated to the position shown by the dashed line in FIG. 4, it is again rotated to the closed position by the bias of the spring 31, and is supported by the stopper 30 at the closed position. In the closed position, the exposure window 2 is formed by the ridges 28 c and 29 provided on the shutter blade 28 and the shutter base 27.
The light shielding in 6 is maintained. One exposure is performed as described above, and a subject image is captured on the film 9. By operating the wind-up knob 8 again to wind up the film 9 and charge the shutter as described above, the shutter drive lever 2 can be operated.
The first arm 21a is rotated to the cocking position, and the next photographing preparation is ready.

In a state where the shutter blade 28 is urged to the closed position by the spring 31 in the process of the above operation, the film unit 1 according to the present invention is provided with the ridge 28c provided on the shutter blade 28 and the shutter base 27. The projection 29 ensures that the light shielding at the exposure window 26 is maintained. Further, the guide ridges 29a provided on the shutter base 27 allow the shutter blades 28 to be driven smoothly.

[0014]

As described above, according to the film unit of the present invention, it is possible to reliably perform light shielding by providing the shutter base and the shutter blade with projections and combining them. In addition, since the guide ridge is provided on the shutter base and the shutter blade is made of plastic, the shutter blade can be smoothly driven, and the processing of the shutter blade becomes easy, which is very effective.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a film unit main body embodying the present invention.

FIG. 2 is an exploded perspective view of a shutter mechanism of the film unit shown in FIG.

FIG. 3 is an external perspective view of the film unit shown in FIG.

FIG. 4 is an explanatory view of a main part of the film unit shown in FIG.

FIG. 5 is a sectional view of a main part of the film unit shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Film unit 2 Unit main body 4 Lens 6 Shutter button 8 Winding knob 9 Film 11 Patrone 16 Spool 18 Shutter mechanism 19 Sprocket 21 Shutter drive lever 26 Exposure window 27 Shutter base 28 Shutter blade 29 Protrusion 30 Stopper 31 Spring

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Koji Kono, Inventor 1-324 Uetake-cho, Omiya City, Saitama Prefecture Inside Fuji Photographic Equipment Co., Ltd. (56) References 3-90232 JP-U (JP, U)

Claims (2)

(57) [Claims] 1. A shutter mechanism for exposing a photographic film through an exposure opening by opening and closing a shutter blade provided on a shutter base having an exposure opening, a ridge provided at a peripheral position surrounding the exposure opening of the shutter base, A projection provided on a surface of the shutter blade facing the exposure opening, and light leakage from a gap between the shutter base and the shutter blade enters the exposure opening by combining the projections with each other in a shutter closed state. A shutter mechanism characterized in that it is not performed. 2. The shutter mechanism according to claim 1, wherein said shutter blade is made of plastic.