JPH07181593A - Film counter mechanism - Google Patents

Abstract

PURPOSE:To surely advance the graduation of a photographed film number display plate by one. CONSTITUTION:A sprocket 34 rotated once by the winding of a film, a one-tooth gear 36 engaged with the teeth array 10a of the photographed film number display plate 10 to advance the graduation by one and a shutter charging gear 37 moving a traveling plate 41 to a charging position via a pinion gear 38 and a rack 41a are provided on a rotary shaft 35 and the shaft 35 is supported so as to approach the photographed film number display plate 10 by oblong holes 45 and 46 and approaches the plate 10 to press the one-tooth gear 36 against the teeth array 10a, by tensile force accompanying the movement of the film 33 and the energizing force of a spring 42 reversed via the pinion gear 38.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a film counter mechanism for displaying the number of shots of a film.

[0002]

2. Description of the Related Art Conventionally, there is provided a lens-fitted film unit as disclosed in Japanese Examined Patent Publication No. 32-32615. This lens-fitted film unit stores 135 film with a patrone in advance in the main body in which a taking lens, a film winding mechanism and a shutter mechanism are incorporated, and covers it light-tightly with a rear cover, and fixes the front cover to the front. It has a structure. With such a lens-fitted film unit, a system has been adopted in which the film-winding film is taken into the cartridge by operating the winding knob for each shooting, and after the shooting is completed, the DPE is requested to the photo lab together with the unit body. There is.

The film winding mechanism including the winding knob has a built-in film counter mechanism for counting the number of photographed images. This film counter mechanism is provided with a scale for displaying the remaining number on the surface and a disk-shaped image number display plate with teeth formed on the outer circumference, and one rotation for each frame that is engaged with the perforation of the film and wound up. The sprocket and the one-tooth gear that is provided coaxially with the sprocket and that meshes with the tooth row of the number-of-photographs display plate to rotate by one graduation. The number-of-photos display panel displays the number of films that can be photographed at that time through a display window exposed to the outside. When the end display mark "E" on the number-of-images display plate appears in the display window by the winding operation after the last frame has been shot, the film winding stop mechanism does not operate and the entire film is completely contained in the cartridge. Is stored in.

[0004]

In order for the film counter mechanism described above to always display the correct number of shots, the one-tooth gear and the number-of-shots display plate must be reliably engaged. Therefore, it is possible to energize the one-tooth gear with a metal spring or the like, but using a spring for pressing causes an increase in the assembly process and an increase in cost, and is adopted in a low-cost lens-fitted film unit. Is not preferable.
It is also possible to make the shape of the one-tooth gear by cutting out a part of the ellipse or pressing it without using a spring by decentering the rotation center, but the toothless part of the one-tooth gear is the number of shots. It is not possible to say that this is a reliable method, because it is possible that the number-of-photographed-images display plate may rotate due to some shock while facing the display plate. Further, in consideration of automatic assembly, a certain clearance is required between the one-tooth gear and the number-of-photographs display plate, which is disadvantageous for reliable display of the number of photos.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a film counter mechanism capable of surely stepping one graduation by one tooth gear for one graduation of the number-of-photographs display plate. .

[0006]

In order to solve the above problems, the film counter mechanism of the present invention is provided with a driven sprocket that makes one rotation by film winding operation of one frame, and is provided coaxially with the driven sprocket, and the number of images to be photographed. A one-tooth gear that feeds the display plate by one graduation, and a gear to which the drive of the driven sprocket is transmitted and meshes with a rack provided on the traveling plate for driving the shutter to move the traveling plate toward the charge position, The rotation axis of the sprocket is supported by a long hole that extends toward the number-of-photos display plate, and the urging force applied to the sprocket during film winding and the urging force that returns the running plate to the initial position allow one tooth The gear is moved in the slot and pressed against the number-of-photos display plate. As a result, the one-tooth gear is pressed against the number-of-shots display plate, so that the number-of-shoots display plate can be stably rotated. Further, since it can be performed without increasing the number of parts, it can be implemented at low cost.

[0007]

EXAMPLE FIG. 2 shows the external appearance of a lens-fitted film unit using the present invention. The lens-fitted photo film unit 2 is of a type designed to be made thinner, and is composed of a unit main body 3 having a photographing mechanism and the like built therein and an outer case 4 for housing the same. Outer case 4
Has a contour that exposes the winding knob 5, the flash light emitting section 6, the shutter button 7 and the like incorporated in the unit main body 3, and the lens hood 8, the object side viewfinder window 9 and the number of shots display panel 10. A hole for exposing the display window 11 and the like for visually recognizing is displayed.

As shown in exploded view in FIG. 3, the unit main body 3 comprises a main body base 12, an exposure unit 13, a strobe unit 14, a rear cover 15 and a front cover 16, which are engaged by a claw engagement. It is detachably attached.

The body base 12 is made of opaque plastic, and a light-shielding cylinder 19 is provided on the optical axis 18. An aperture that determines the exposure range of the photographic film is formed on the back side. On both sides of the light-shielding tube 19, a cartridge storage chamber 20 for storing a cartridge,
Film roll chamber 2 for storing the film in roll form
1 and 1 are formed. The front surface of the outer wall of the cartridge storage chamber 20 has a shape projecting more forward than the front surface of the outer wall of the film roll chamber 21.

The strobe unit 14 is a printed circuit board 2
4 and a light emitting unit 25. Printed circuit board 2
4, an electric component 24a forming a strobe circuit and a light emitting switch 24b turned on by a shutter mechanism of the exposure unit 13 are attached. Also, the light emitting unit 2
Reference numeral 5 denotes a discharge tube, a reflector, and a diffuser plate 25a held by a resin holder 25b.

The rear cover 15 is made of opaque plastic, and has a film supporting surface 15a formed at a portion facing the aperture. Pull-top lids 15b and 15c for covering the bottom surfaces of the cartridge storage chamber 20 and the film roll chamber 21 are provided on the bottom side. The lid 15b serves as a take-out lid when taking out the cartridge containing the exposed film.

The front cover 16 is made of transparent plastic and has a shutter button 7, a lens hood 8, an object side viewfinder window 9, a display window 11, a strobe charging switch 27, a pilot lamp window 28 and the like. .
The front cover 16 is formed with a protrusion 29 that matches the protrusion of the cartridge storage chamber 20.
Is a grip when shooting.

The exposure unit 13 includes a base 30 made of opaque plastic, a film winding mechanism, and a film winding mechanism.
A counter mechanism, shutter mechanism, etc. are incorporated. A photographing lens 31 is incorporated in the front surface side of the base portion 30, and a finder 32 is incorporated in the upper portion of the base portion 30. The exposure unit 13 is detachably attached to the front surface of the main body base 12.

FIG. 1 shows a film counter mechanism. When the film 33 is wound up and moved in the arrow X direction in the figure, the sprocket 34 engaging with the perforation 33a is rotated counterclockwise about the rotation shaft 35. The sprocket 34 rotates once when the film 33 is wound up one frame. A one-tooth gear 36, a shutter charge gear 37, and a sprocket 34 are integrally formed on the rotary shaft 35 from the upper side. The one-tooth gear 36 has a V-shaped notch formed in the rotary shaft 35, and meshes with the tooth row 10a on the outer periphery of the number-of-photographs display plate 10 pivotally attached to the shaft 10b to form the number-of-photographs display plate 10. 1
Rotate by the scale.

A pinion gear 38 is meshed with the shutter charge gear 37. The pinion gear 38 is pivotally mounted on a pin 39 formed on the base portion 30 of the exposure unit 13, and is freely rotatable and slid downward. The downward sliding is regulated by being biased by the coil spring 40, and the downward sliding of the pinion gear 38 is performed in conjunction with the depression of the shutter button 7.

The pinion gear 38 is meshed with a rack 41a formed on a traveling plate 41 for shutter release. The traveling plate 41 is moved against the spring 42 in the direction of the arrow Y in the figure by the rotation of the pinion gear 38. Then, by pressing the shutter button 7, the pinion gear 38
When is slid downward, the engagement between the pinion gear 38 and the rack 41a is released, and the traveling plate 41 is returned to the state shown in the figure by the bias of the spring 42. At that time, the projection 41b formed on the traveling plate 41 kicks off the contact piece 43a of the shutter blade 43, and rotates clockwise about the shaft 43b against the spring 44 to expose the film 33. .

As shown in FIG. 4, a sprocket 34, a one-tooth gear 36, and a rotary shaft 35 of a shutter charge gear 37.
Is supported by oblong holes 45 and 46 up and down, and is movable toward the number-of-photographs display plate 10. As shown in FIG. 5, the rotating shaft 35 has a pulling force 47 applied to the sprocket 34 from the film 33 at the time of film winding, and a spring 42 of the running plate 41 applied to the shutter charge gear 37 as a reaction force by the pinion gear 38. The rotating shaft 35 is moved in the direction of the arrow Z in the figure by the urging force 48, and the one-tooth gear 36 is pressed against the photograph number display plate 10.

Next, the operation of the lens-fitted film unit constructed as described above will be described. From the display window 11 of the lens-fitted film unit 2, the number-of-photos display plate 10 on which a number indicating the number of remaining images is displayed can be visually recognized. From this display, the usage state of the lens-fitted film unit 2 can be confirmed. For example, the "." Mark is displayed when it is not used, and the "E" end mark is displayed when all frames are shot.

When the lens-fitted film unit 2 is not used, the photographer turns the winding knob 5 to charge the shutter in preparation for photographing. As shown in FIG. 5, when the winding knob 5 is rotated, the film 33 is wound into the cartridge in the leftward direction in the drawing. The sprocket 34 engaged with the perforation 33a of the film 33 is rotated in the counterclockwise direction and is pulled by the pulling force 47 of the film 33, so that the rotation shaft 35 is moved to the long hole 4a.
It moves within 5, 46 and moves in the direction of approaching the number-of-photographed display plate 10. At the same time, the shutter charge gear 37
Thereby, the pinion gear 38 is rotated in the clockwise direction, and the traveling plate 41 provided with the rack 41a meshing with the pinion gear 38 moves leftward in the drawing against the spring 42. Biasing force of spring 42 48
Is given to the shutter charge gear 37 in the opposite direction via the pinion gear 38, and the rotary shaft 35 is provided with a long hole 45,
It moves in the direction 46 and moves in the direction of approaching the number-of-photographed display plate 10. In this way, the one-tooth gear 36 formed on the rotary shaft 35 is pressed against the number-of-photographed image display plate 10 and surely meshed by the pulling of the film and the spring bias of the shutter charge. In this winding operation, the rotation of the winding knob 5 and the sprocket 34 is blocked by a well-known winding stop mechanism (not shown), and the winding of the film is restricted.

In the traveling plate 41 moved by the pinion gear 38, the projecting piece 41b is the contact piece 43a of the shutter blade 43.
Move over the top to complete the shutter charge. At this time, the number of recordable images of "27" is displayed in the display window 11.

When the shutter button 7 is depressed from the shutter charged state, a rod (not shown) formed integrally with the shutter button 7 pushes down the pinion gear 38 against the spring 40. When the pinion gear 38 is pushed down, the engagement between the pinion gear 38 and the rack 41a is released, and the traveling plate 41 is returned to the initial position by the bias of the spring 42. At this time, the projection 41b of the traveling plate 41 kicks the contact piece 43a of the shutter blade 43 and rotates it around the shaft 43b to perform shutter release.

When the shutter button 7 is released after the shutter release, the pinion gear 38 slides upward due to the urging force of the spring 40, meshes with the rack 41a, and shutter charging is enabled again. When the winding knob 5 is operated, shutter charging and film winding are performed. At this time, the one-tooth gear 36 is displayed on the number-of-photographs display plate 10 by pulling the film 33 and urging the shutter charging spring 42. When pressed, the number-of-photographs display plate 10 is reliably rotated by one scale.

In the above embodiment, the lens-fitted film unit is used for explanation. However, the film counter mechanism of the present invention can be applied to a low-priced manually wound camera.

[0024]

As described above, in the film counter mechanism of the present invention, the rotating shaft of the one-tooth gear for rotating the number-of-photos display plate is supported by the long hole so that it can approach the number-of-shoots display plate, and this rotation is performed. Since the shaft is pressed against the number-of-photos display plate by using the pulling force when the film is wound and the spring bias of the shutter charge, it is possible to surely display the number of stable images. Further, since it is not necessary to increase the number of parts or the number of assembling steps in order to carry out the present invention, the present invention can be carried out at low cost.

[Brief description of drawings]

FIG. 1 is an external perspective view showing the configuration of a film counter mechanism.

FIG. 2 is a perspective view showing the outer appearance of a lens-fitted film unit.

FIG. 3 is an exploded perspective view showing a configuration of a unit main body.

FIG. 4 is a sectional view of a main part of a film counter mechanism.

FIG. 5 is a plan view of a film counter mechanism.

[Explanation of symbols]

 2 Film unit with lens 10 Number of shots display plate 33 Film 34 Sprocket 35 Rotation shaft 36 Single tooth gear 37 Shutter charge gear 38 Pinion gear 41 Travel plate 41a Rack 42 Spring 45,46 Long hole

Claims (1)

[Claims] 1. A driven sprocket that makes one rotation by a film winding operation of one frame, a one-tooth gear that is provided coaxially with the driven sprocket, and feeds the number-of-photographs display plate by one scale, and the drive of the driven sprocket is transmitted. In a film counter mechanism having a gear for moving a traveling plate toward a charge position by meshing with a rack provided on a traveling plate for driving a shutter, a rotation shaft of the sprocket extends toward the photograph number display plate. It is supported in the elongated slot, and by the biasing force applied to the sprocket during film winding and the biasing force that returns the running plate to the initial position, the slot is moved and the one-tooth gear is displayed on the number-of-images display plate. A film counter mechanism characterized by pressing.