JPH09101560A - Sprocket and camera using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely feed a film frame and charge a shutter from force for transferring a photographic film provided with perforations arrayed alternately at two kinds of intervals. SOLUTION: A sprocket 29 is constituted of a wheel member 27 having a pair of teeth 27a and 27b engaged with a pair of perforations arranged side by side at a short interval and a rubber band 28 arranged exposedly on the circumference of the wheel member 27, in a state where a pair of the teeth 27a and 27b are exposed outside and the circumferential length of the sprocket 29 is made shorter than the one-frame feeding length of the film. Since the rubber band 28 has a great frictional resistance to the photographic film, the force for transferring the film can be surely transmitted to the wheel member. Further, the rubber band 28 has a circular cross-section, so that a contact area is reduced and when the preceding teeth are abutted on the film and the rotation of the sprocket is stopped, only the transfer of the film can be permitted by slipping.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sprocket for securing one frame advance of a film and a camera using the sprocket, and more specifically, a sprocket used for a photographic film provided with two perforations per frame, and It relates to a camera using this.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 5-19368 proposes a photographic film having two perforations per frame. These two perforations are provided at the position corresponding to the beginning of each frame and the position corresponding to the trailing end of each frame, and it is premised that each frame is photographed between these perforations. For this reason, the perforations are alternately arranged at two types of intervals, a long interval for determining the center of a frame and a short interval for determining the mutual interval of each frame. The length obtained by adding the long interval and the short interval is set as the one-frame feed length.

The Applicant has provided a pair of teeth that engage a pair of shortly spaced perforations as a means suitable for realizing the film feeding of such a format at a relatively low cost. Using the sprocket, the intermittent sprocket is intermittently rotated once in response to the transfer of one frame of film, and the rotation of the intermittent sprocket is locked by inserting the pawl into the cam groove that rotates in synchronization with this, and the film is wound up. Japanese Patent Application No. Hei 7-7, which prevents the shutter charge and uses the rotation of the intermittent sprocket during this time to perform shutter charging against the bias of the charge spring by the charge cam.
No. 32413 proposed. Since such a film winding stop mechanism and shutter charge mechanism mechanically detect the movement of the perforation, the film transfer for one frame can be surely detected, and the shutter charge is changed by the teeth of the intermittent sprocket to the perforation. By performing the operation during the engagement, it is possible to resist the strong bias of the charge spring applied to the shutter. If this intermittent sprocket is molded with a resin material, it can be mass-produced and the cost is reduced.

[0004]

However, on the circumferential surface of the intermittent sprocket other than during the engagement of the pair of teeth with the pair of perforations arranged at a short interval, the intermittent sprocket itself is made of resin. Because it has been
Since there is almost no frictional resistance with the photo film, the intermittent sprocket may not rotate following the photo film. Further, when the intermittent sprocket is arranged so that the circumferential surface is strongly pressed against the photographic film, the photographic film may be damaged.

The present invention has been made in consideration of the above circumstances, and uses a photographic film in which perforations are formed at intervals of two types, long and short, so that the rotational force can be reliably taken out from the transfer of the photographic film. It is an object to provide a devised sprocket and a camera using the sprocket.

[0006]

In order to achieve the above object, according to the present invention, a pair of teeth for engaging a pair of perforations arranged at short intervals among the perforations are provided, and when the pair of perforations move. ,
After the leading tooth of the two teeth comes into contact with the photographic film and the rotation following the film winding is prohibited, the leading tooth is engaged with the corresponding perforation on the circumferential surface. Allowing the photographic film to be transferred while slipping, and rotating the film by a predetermined rotation when the subsequent tooth engages with the corresponding perforation, while the pair of teeth engages with the pair of perforations. A wheel moving member that performs shutter charging against the bias of the spring by the film transfer force obtained in the above ;; and is disposed so as to be exposed on the circumferential surface of the wheel moving member with the pair of teeth protruding to the outside. And a ring-shaped elastic body. According to this, since the elastic body is used, it is possible to improve the friction resistance with the photographic film. The elastic body is made of rubber or a resin material having elasticity, and preferably has a circular cross section, but is not limited to a circular shape.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A photographic film cartridge 10 shown in FIG. 1 comprises a cartridge 11 and a photographic film 12, and a spool 13 is rotated in the film feeding direction to move the photographic film 12 to the leading end 1 of the film.
2a is sent to the outside.

In this photographic film 12, a frame positioning perforation group 14 is formed on one edge in the film width direction along the film feeding direction. The frame-positioning perforation group 14 is formed by continuously forming perforations 14a to 14z at two different types of intervals in a shooting region used for shooting, and a short interval L1 and a long interval L2 in this order from the film tip 12a. It is arranged. In the camera, the film is fed by one frame so that the center of the aperture in the longitudinal direction is aligned with the center of the perforations 14 having the long interval L2, and the photographed frames 15a to 15z are formed in the size of the aperture. The one-frame feeding length is the length of the interval L1 + L2. The length of the shooting area is determined according to the specified number of shots.

A sprocket 1 for converting a linear transfer of the photographic film 12 into a rotation by using the photographic film 12 and operating a shutter charge, a film winding stop, a film counter, etc. by this rotational force. 2 and 4, as shown in FIG. 2 to FIG.
A ring-shaped rubber (hereinafter, referred to as "rubber") 3 including a ring and the like. The wheel moving member 2 is provided with a pair of teeth 2a and 2b which are engaged with the perforations 14 arranged at short intervals L1, and a shaft 2c for rotationally taking out the drive obtained from the film transfer is formed on the circumferential surface 2d.
Is formed in the center of. The rubber band 3 is in the form of a belt having a vertically long rectangular cross-section, and has holes 3a, 3b for exposing the pair of teeth 2a, 2b to the outside when fitted into the circumferential surface 2d of the wheel moving member 2. Is provided. This sprocket 1 is equipped with a rubber band 3 for the film passage of the camera.
Is arranged such that the outer periphery of the photo film 12 is at a position to slightly press the photographic film 12, and the rubber band 3 presses the photographic film 12 to generate a frictional force with the photographic film 12.

The rubber band 3 has an inner circumference shorter than the circumferential surface 2d of the wheel moving member 2. The circumferential surface of the sprocket 1 after the rubber band 3 is fitted is set to be the same as the one-frame feeding length of the film. However, in order to securely engage the teeth 2a and 2b with the perforations 14, it is desirable that the circumferential surface of the sprocket 1 be shorter than the one-frame feeding length of the film. In this case, the perforation 14 and the circumferential surface of the rubber band 3 where the teeth 2a and 2b are not exposed.
While in contact with the photographic film 12 in the non-exposed portion, the sprocket 1 is rotated by the transfer of the photographic film 12 due to the frictional resistance of each other, and the teeth 2a are engaged with the photographic film 12 before engaging with the perforations 14. And is prevented from rotating. After the rotation is blocked, the rubber band 3 and the photographic film 12 slip, and the rubber band 3 allows the photographic film 12 to be transferred. When the perforations 14 reach, the teeth 2a are engaged and rotate. When the intermittent rotation makes one rotation, the film winding stopping means is operated, and the spring is generated by the rotational force obtained while the pair of teeth 2a and 2b engages the pair of perforations 14 arranged at the short interval L1. The shutter is charged against the bias of.

Sprocket 29 shown in FIGS. 5-8.
Is an example of another form. The rubber band 28 has a circular cross section, and the pair of teeth 2 on the circumferential surface of the wheel moving member 27.
7a, 27b and the circumferential surface 27c between them are fitted into the circumferential surface. A groove 27d for fitting the rubber band 28 is formed on the circumference of the wheel moving member 27 corresponding to this section. The sprocket 29 is arranged such that the outer periphery of the rubber band 28 is slightly pressed against the photographic film 12 with respect to the film passage of the camera. According to this, since the contact portion having a circular cross section of the rubber band 28 in contact with the photographic film 12 is slightly crushed, the contact area is smaller than that of the rubber band 3 having a rectangular cross section, and a certain amount of deformation is caused. Requires less force than the rectangular cross section, and it is easy to slip between the photo film 12 and the sprocket with the rectangular cross section, so no large force is generated between the photo film 12 and the pressure plate or sprocket, so the film is The feeding power is small. The cross-sectional shape of the rubber band is not necessarily limited to the circular shape, and may be a quadrangular cross section, a trapezoidal shape, a triangular shape, or the like. Further, the pair of teeth 27a, 27b are formed with a circumferential interval of a short interval L1, and the circumferential length L3 exposed by the rubber band 28 is shorter than the interval L2 of the perforations 14. .

The above-mentioned sprocket 1 (or 2)
9) is the rubber band 3 on the photographic film 12 to be fed.
(Or 28) frictionally engages with each other to rotate in a driven manner, and the perforation 14 has the two teeth 2a,
Since 2b (or 27a, 27b) has an engagement rotation range in which it engages and is driven to rotate, as described above, the photographic films other than the photographic films 12 arranged at two types of intervals, for example, arranged at least at short intervals. It can also be used for photo films with perforations and photo films in which perforations are arranged in series at short intervals.
In this case, when the sprocket 1 (or 29) rotates following the feeding of the film in the winding direction, the sprocket 1 (or 2) is rotated in at least a part of the engagement rotation range.
While 9) rotates, the shutter charge of the shutter charge mechanism of the camera may be performed in conjunction with the rotation. In this case, since no load is applied by the shutter charge spring or the like in the friction engagement region, the rubber band 3 (or 28) is not required to be engaged with the perforations one by one.
Since the sprocket is driven to rotate only by the frictional engagement, the cost can be reduced as compared with, for example, a sprocket having teeth all around.

In the above embodiment, the elastic body is made of rubber. However, the present invention is not limited to rubber and may be made of a resin material having elasticity.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A camera film feeding device using the sprocket 29 described with reference to FIGS. 5 to 8 will be described below.
As shown in FIG. 9, the camera is provided with a patrone chamber on the left side of the aperture 17 and a film winding chamber on the right side. This aperture 17
It has a curved shape centering on the optical axis 18a of the taking lens 18 together with the film passage passing behind.

A photographic film cartridge 10 is loaded in the cartridge chamber along the axial direction of the spool 13. At both ends of the spool 13, key grooves are formed which are exposed to the outside from both side surfaces of the cartridge 11. A drive shaft 20 provided in the cartridge chamber of the camera engages with the key groove 19 among these key grooves, and the spool 13 is rotated by the drive of the drive shaft 20.

The film entrance 21 is provided in the cartridge 11.
A lid member for shading the inside of the cartridge is built inside. The lid member is rotatably provided between a closed position that closes the film entrance 21 and an open position that opens the film entrance 21. On both end faces of this lid member, key grooves are formed which are exposed to the outside from both side faces of the cartridge 11. A drive shaft 23 for opening and closing the lid member provided in the cartridge chamber is engaged with the key groove 22 among these key grooves. The drive shaft 23 rotates the lid member to the closed position in conjunction with the opening movement of the bottom lid that opens the cartridge chamber of the camera, and rotates the lid member to the open position in association with the closing movement of the bottom lid that closes the cartridge chamber. To move.

Since the drive shafts 20 and 23 project from the interior of the cartridge chamber along the loading direction of the photographic film cartridge 10, when the bottom lid is opened and the photographic film cartridge 10 is loaded, the key groove 19 is formed. The drive shaft 20 for driving the spool smoothly engages with the key groove 22, and the drive shaft 23 for opening and closing the lid member engages with the key groove 22 smoothly.

After the lid member is rotated to the open position in association with the closing operation of the bottom lid, the drive of the film feeding motor 24 in the forward direction is started. This drive is transmitted to the drive shaft 20, and the spool 13 rotates in the film feeding direction. The sent photographic film 12 is sent to the film winding chamber through the film passage having the aperture 17.

The film winding chamber has a winding shaft 25.
Is rotatably arranged. The drive of the motor 24 is decelerated and transmitted to the take-up shaft 25 by a gear train or the like, and the fed-out photo film 12 is taken up from the leading end 12a of the film. A slip mechanism is incorporated between the motor 24 and the drive shaft 20. This slip mechanism
The difference between the rotation of the winding shaft 25 and the rotation of the motor 24, which are thick as the photographic film 12 is wound, is absorbed.

After the shooting of the last frame 15z is completed, the film rewinding operation is performed. By this operation, the motor 24 is driven in reverse. At this time, the reverse rotation drive is not transmitted to the take-up shaft 25 by the clutch 26 incorporated between the photo film 1 and the take-up shaft 25.
2 is stored inside the cartridge 11 by the rotation of the spool 13 in the film winding direction.

Aperture 1 viewed from the side of the taking lens 18
7 and at a position closer to the film winding chamber side than the photographing optical axis 18a, the sprocket (hereinafter referred to as "intermittent sprocket") 29 described with reference to FIGS.
Is rotatably arranged in a state in which the rotation path of the pair of teeth 27a, 27b is exposed in the film passage.

In the photographic film 12 shown in FIG. 1, a perforation 16 for detecting the end of the film is formed at an edge opposite to the perforation 14 on the film rear end 12b side of the last frame 15z. The distance between the perforations 16 and 14z in the film feeding direction is shorter than the short distance L1.

Below the intermittent sprocket 29, a film end detecting claw 50 which engages with the perforation 16 for detecting the end is provided. The film end detecting claw 50 is rotatable between an engaging position for engaging the perforation 16 and a retracting position for retracting from the engaging position, and is biased by a spring 51 toward the engaging position.
This film end detection claw 50 is used for perforation 16
By engaging with, the film winding is prevented from further winding. The film tip 12a of the photographic film 12
Is the perforation 1 of the film tip 12a.
Since the shape on the extension line of 6 is the tapered surface 12c, the film end detecting claw 50 is not caught.

In the intermittent sprocket 29, when the film winding stopping means, which will be described later in detail, operates, the preceding tooth 27a is disengaged from the perforation 14 along the rotational direction following the film winding direction, and the following tooth 27b is formed. Stops at one rotation position where it engages with the perforation 14. Then, one rotation of the film is performed by feeding one frame.

The rotation of the intermittent sprocket 29 is transmitted to the shutter charging means, the film winding stopping means, the counter means and the like via a gear 30 coaxially provided and a gear 31 meshing with the gear 30. As shown in FIG. 10, the shutter charging means and the film winding stopping means include a shutter charging cam 33, a winding stopping cam 34, and a locking lever 3.
5, a shutter drive lever 36, a torsion spring 37, and the like. The shutter charge cam 33 is provided coaxially with the gear 31, and synchronizes with the rotation of the intermittent sprocket 29. Further, the winding stop cam 34 has an annular shape in which a groove 34a is formed at a predetermined position on the circumferential surface, and is provided coaxially with the shutter charge cam 33.

The locking lever 35 has one end 35a, a pressure receiving portion 35b, a falling piece 35c, and a falling protrusion 35.
d and the switch pressing piece 35e are integrally formed, and these are rotatably provided around the shaft 38. The groove 34a is located at one rotation position of the intermittent sprocket 29 within the rotation locus of the one end 35a. Lock lever 3
When the shutter charge is completed, the one end 35a rotates into the winding stop position where the one end 35a enters the groove 34a to prevent the rotation of the intermittent sprocket 29, and the one end 35a retracts from the groove 34a after the shutter release is completed and the intermittent sprocket 29 is rotated.
Unlock the rotation lock of the.

One end 37a of the torsion spring 37 is hooked on the falling piece 35c of the locking lever 35, and biases the locking lever 35 around the shaft 38 toward the winding stop position. The switch pressing piece 35e is the locking lever 35.
Switch ON when is rotated to the unwinding release position
I do.

When the shutter drive lever 36, which will be described in detail later, rotates to the charging position, the falling protrusion 35d enters the turning locus of the rising protrusion 36c and holds the shutter driving lever 36 at the charging position.
The falling piece 35c is a rod piece 39 provided below the shutter button 39 that is pressed by the shutter release.
It is pushed toward the unwinding release position with a. Lock lever 3
When 5 moves to the unwinding release position, the falling protrusion 35d retracts from the rotation locus of the rising protrusion 36c and releases the holding of the shutter drive lever 36 at the charge position. The shutter button 40 is, for example, an elastic button formed by cutting out a part of the upper surface of the camera body, and is below when the shutter button 39 is pressed.
A switch 40 for N is arranged.

One end 36a of the shutter drive lever 36 faces the rotation trajectory of the shutter charge cam 33. In addition to the one end 36a, a kicking piece 36b, a rising protrusion 36c, a spring receiving portion 36d, and a pressure receiving portion 36e are integrally formed on the shutter drive lever 36, and are rotatable about a shaft 41. It is provided. The rotation of the shutter drive lever 36 is performed between a charge position where one end 36a is pushed by the shutter charge cam 33 to be charged and a release completion position which is rotated in a direction opposite to the charging direction.

The other end 37b of the torsion spring 37 is hooked on the spring receiving portion 36d of the shutter drive lever 36, and the shaft 4
The shutter drive lever 36 is urged around the position 1 toward the release completion position.

The kick-off piece 36b is provided with the shutter blades 4 while the shutter drive lever 36 rotates from the charging position to the release completion position by the urging force of the torsion spring 37.
Kick 2 When the shutter blade 42 is kicked, the shutter blade 42 rotates clockwise about the shaft 43 to expose the shutter opening 44. After that, it is instantly returned to the original position by the pull-back spring 45.

When the shutter drive lever 36 rotates to the release completion position, the rising protrusion 36c enters the turning locus of the falling protrusion 35d of the locking lever 35 and holds the locking lever 35 at the unwinding release position. .

While the intermittent sprocket 29 is rotated by feeding the film one frame, the shutter charge cam 33 is rotated.
The shutter drive lever 3 against the bias of the torsion spring 37.
Rotate 6 from the release complete position toward the charge position. Therefore, the shutter charge has two teeth 27.
The shape of the shutter charge cam 33 is considered so as to be performed by the rotational force of the intermittent sprocket 29 while the a and 27b are engaged with the perforation 14. And
When the intermittent sprocket 29 reaches one rotation position by the transfer of one frame of film, the shutter charge cam 33 stops at a position past the rotation locus of the one end 36a of the shutter drive lever 36, and the shutter drive lever is subsequently released by the shutter release. 36 can rotate to the release completion position.

The counter means is composed of a one-tooth gear 48 and a number display plate 49. The one-tooth gear 48 is provided coaxially with the winding stop cam 34, and advances the count display plate 49 by one graduation by one rotation of the intermittent sprocket 29. The number display plate 49 is rotatably arranged on the shaft 41, and the scale is displayed on the upper surface. The scale is
By advancing one step, the number of frames photographed is displayed in a forward calculation formula through a display window 58 provided outside the camera body.

The motor 24 transfers the photographic film 12 in the film winding direction by turning on the switch 46 when the locking lever 35 is in the unwinding release position and turning off the switch 40 after the pressing operation of the shutter button 39 is completed. Drive forward as if Then, the lock lever 35 is rotated to the winding stop position by moving the film one frame, and the switch 46 is turned off, so that the normal rotation drive of the motor 24 is stopped.

The film rewinding after the completion of photographing is started by sliding the external switch member 52 exposed to the outside of the camera body from the normal position to the rewinding position. The external switch member 52 has two pressing portions 52a,
52b and the switch pressing piece 52c are integrally provided. The two pressing portions 52a and 52b respectively press the pressure receiving portions 35b and 36e of the locking lever 35 and the shutter drive lever 36 when the external switch member 52 moves to the rewinding position, and the locking lever 35 is moved. The unwinding release position and the shutter drive lever 36 are forcibly rotated to the charge position and held in this state. As a result, the drive transmission between the intermittent sprocket 29, the film winding stopping means, and the shutter charging means is cut off, the winding stopping operation of the film winding stopping means is prevented, and the intermittent sprocket 29 remains charged in the shutter charging means. Rotation is free.

The switch pressing piece 52c turns on the switch 53 when the external switch member 52 moves to the rewinding position. The switch 53 is a switch for driving the motor 24 in the reverse direction. By this film rewinding, the intermittent sprocket 29 is perforated 1
While rotating in reverse while meshing with 4, the one-tooth gear 48 advances the number display plate 49 in the reverse direction toward the initial display position.

The control circuit of the motor 24 is shown in FIG. 11 and FIG.
It is shown in FIG. In the normal rotation drive of the motor 24, the switch 46 is set to O.
N, and the moment the switch 40 is turned off. Then, when the switch 46 is turned off, the normal rotation drive of the motor 24 is stopped. However, in the film winding after the shooting of the last frame 15z is completed, the switch 46 is not turned off because the film winding stop does not operate. Therefore, a circuit configuration that automatically stops the normal rotation drive of the motor 24 even if the switch 46 is not turned off is required. Therefore, this circuit is provided with the capacitor 24b and the like, and the normal rotation drive of the motor 24 is automatically stopped when the voltage accumulated in the capacitor 24b drops to a certain level. The capacitor 24b starts to be charged when the shutter button 39 is pressed (when the switch 40 is turned on), and is charged when the shutter button 39 is pressed (when the switch 40 is turned off). .

The time from when the charging of the capacitor 24b is cut off until the charging voltage drops to a constant level is set to be longer than the one frame feeding time of the film.
Reference numeral 53 is a switch for detecting the rewinding position of the external switch member 52 described above. When this switch is turned on, the reverse drive of the motor 24 is started, and when it is turned off, the reverse drive of the motor 24 is stopped.

Next, the operation of the above embodiment will be described. The bottom lid of the camera is opened, the photographic film cartridge 10 is loaded, and the bottom lid is closed. The drive shaft 23 rotates in conjunction with the closing operation of the bottom lid, and rotates the lid member to the open position. At this time, the number display plate 49 is in the initial display position.
As shown in FIG. 13, the intermittent sprocket 29 is stopped at the initial position in which the pair of teeth 27a and 27b are retracted from the feeding path of the photo film 12 along the driven direction of film winding.

As shown in FIG. 14, the film winding stopping means and the shutter charging means are such that the locking lever 35 is in the winding stopping position, and the one end 35a is in the groove 34a.
It enters to prevent the intermittent sprocket 29 from rotating clockwise. Further, the locking lever 35 holds the shutter drive lever 36 at the charge position by causing the falling protrusion 35d to enter the rotation locus of the rising protrusion 36c.

The first film winding operation is started by pressing the shutter button 39. When the shutter button 39 is pressed, the switch 40 is turned on, the contacts 40a and 40b shown in FIG. 11 are connected, and the capacitor 24b is started to be charged by the voltage from the power supply battery 24a. This time point is time t1 shown in FIG.

On the other hand, when the shutter button 39 is depressed, the rod 39a pushes the locking lever 35 counterclockwise to rotate it to the unwinding release position. At this time, FIG.
As shown in FIG. 5, the falling protrusion 35d is retracted from the rotation locus of the rising protrusion 36c, the holding of the shutter drive lever 36 at the charge position is released, and the shutter drive lever 36 instantaneously rotates counterclockwise. Although the shutter blades 42 are kicked off by the shutter, the photo film 12 is not sent out, so that the photo film 12 is not exposed. After that, the shutter drive lever 36 moves to the release completion position to hold the locking lever 35 in the unwinding release position.

When the locking lever 35 is rotated to the unwinding release position, the switch 46 is turned on. Then, when the pressing of the shutter button 39 is stopped (time t2 shown in FIG. 12)
Then, since the switch 40 is turned off, the contact 40a and the contact 40c are connected to drive the motor 24 in the normal direction. As a result, the initial film winding is started.

The length of the film from the leading end 12a of the film to the first perforation 14a is longer than the feeding length for one frame. During feeding in this section, the voltage accumulated in the capacitor 24b may drop to a certain level and the driving of the motor 24 may stop. However, at this time, the shutter button 39 is pressed again to operate the motor 24. There is no problem because it drives.

The photographic film 12 sent out by the normal rotation drive of the motor 24 is sent toward the winding chamber while pushing the film end detecting claw 50 to the retracted position by the taper portion 12c of the film leading end 12a, and the winding shaft 25. To be wound up. Intermittent sprocket 2 by this film feeding
9 rotates in the driven direction of film winding, and as shown in FIG. 16, the leading tooth 27a of the pair of two teeth 27a, 27b contacts the photographic film 12 until the perforation 14a reaches. In this state, the rubber band 28 slips on the photographic film 12 and allows the photographic film 12 to be fed.

When the photographic film 12 is subsequently sent, the first perforation 14a arrives. At this time, since the rubber band 28 and the photographic film 14 are slipping, the frictional force causes the preceding tooth 27a to enter the perforation 14a, and thereafter, as shown in FIG. 17, the preceding tooth 27a moves from the first perforation 14a. When disengaged and the subsequent tooth 27b engages the next perforation 14b, the intermittent sprocket 29 comes to one rotation position.

During this time, the shutter charge cam 33 rotates the shutter drive lever 36 in the clockwise direction, and when the shutter charge lever rotates to the charge position, the rising protrusion 3 is rotated.
6c falls and moves out of the rotation locus of the projection 35d.
As a result, the locking lever 35 is rotated toward the winding stop position (clockwise) by the urging force of the torsion spring 37. At this time, the falling protrusion 35d enters the turning locus of the rising protrusion 36c to hold the shutter drive lever 36 at the charge position.

When the locking lever 35 rotates toward the winding stop position, the rotation of the locking lever 35 is stopped at the position where the one end 35a abuts the outer circumference of the winding stop cam 34, and the intermittent sprocket 29 moves to one rotation position. When rotated, the one end 35a enters the groove 34a, and the locking lever 35 moves to the winding stop position. When the locking lever 35 is rotated to the winding stop position, the switch 46 is turned off and the contact 4 shown in FIG.
6a and the contact 46c are connected, and the forward rotation drive of the motor 24 is stopped at time t3 shown in FIG. As a result, the film winding stopping means and the shutter charging means return to the states described in FIG. 14, and the initial film winding is completed. Then, in the aperture 17, the first frame 1
5a is set.

In the counter means, the one-tooth gear 48 advances the number display plate 49 by one graduation by the rotation of the intermittent sprocket 29 during the initial film winding, and when the first top 15a is set, the display is made. The number of frames to be photographed “1” is displayed on the window 58.

When taking a picture, the shutter button 39
Press the button. As a result, as described with reference to FIG. 15, the falling piece 35c is pushed by the rod piece 39a and the locking lever 35 is rotated toward the unwinding release position. During this rotation, the rising protrusion 36c and the falling protrusion 35c are rotated. The engagement with 35d is released, and the shutter drive lever 36 moves toward the release completion position by the urging of the torsion spring 37. During this time, the shutter blade 42 is kicked off to perform the exposure.

When the shutter drive lever 36 is rotated to the release completion position, as described above, the locking lever 35 is used.
Is held in the unwinding release position, the next film winding is allowed and the switch 46
Is ON.

When the pressing operation of the shutter button 39 is stopped, the switch 40 is turned off and the normal rotation driving of the motor 24 is started. The spool is rotated in the film feeding direction by the normal driving of the motor 24, and the photographic film 15 is fed. Then, when the intermittent sprocket makes one revolution, the intermittent sprocket makes one revolution position again, and after the film is wound, the driving of the motor 24 is stopped. This gives 2
The th frame 15b is set in the aperture 17.
Then, during this period, the shutter charge and the step count corresponding to one scale of the number display plate 49 are performed.

Hereinafter, in the same manner as described above, the shutter button 3
The film can be wound up by performing only the pressing operation of 9, and shooting can be performed sequentially. Then, during the winding of the final film after the shooting of the last frame 15z is completed, the film end detection claw 50 enters the perforation 16 and blocks the transfer of the photographic film 12 in the film feeding direction. After that, the capacitor 24b
The forward rotation drive of the motor 24 is stopped when the voltage accumulated in the voltage drops to a certain level.

When the final winding is completed, the number display plate 49 displays the prescribed number of images in the display window 58, for example, "40".
Is displayed.

After confirming this display, the photographer sets the external switch member 52 for actuating the film rewinding operation as shown in FIG.
It is slid in the direction of arrow B indicated by. By this sliding operation, the two pressing portions 52 of the external switch member 52 are
a and 52b push the pressure receiving portions 35b and 36e to hold the locking lever 35 in the unwinding release position and the shutter drive lever 36 in the charging position. As a result, rotation transmission between the intermittent sprocket 29, the film winding stopping means, and the shutter charging means is cut off,
The intermittent sprocket 29 becomes free. At this time,
The switch pressing piece 52c formed integrally with the external switch member 52 turns on the switch 53.

When the switch 53 is turned on, the reverse rotation drive of the motor 24 is started. As a result, the spool 13 rotates in the film winding direction, and the photographic film 12 is stored inside the cartridge 11. At this time, the intermittent sprocket 29 rotates following the rewinding direction of the photographic film 12, and rotates in a direction opposite to the rotating direction when the film is wound while meshing with the perforations 14. The rotation of the intermittent sprocket 29 is transmitted to the counter means, and the one-tooth gear 48 returns the number display plate 49 toward the initial display position.

When the photographed film 12 is completely housed inside the cartridge 11, the load on the motor 24 is reduced and the motor sound changes. This change sound makes the photographer feel uncomfortable and can visually confirm the display on the display window 58. When the photographer recognizes that the display in the display window 58 is the initial display, the external switch member 52 is slid in the direction opposite to the arrow B direction shown in FIG. 18 to end the film rewinding. . As a result, the reverse rotation drive of the motor 24 is stopped.

When the external switch member 52 is slid, the state shown in FIG. 18 is returned to the state shown in FIG. 14, which is the initial state of the film winding stopping means and shutter charging means. That is, the two pressing portions 52a and 52b release the pressing on the pressing receiving portions 35b and 36e. Of these, since the pressing portion 52a is an inclined surface, the pressing of the pressing portion 52a is released earlier than the pressing portion 52b. As a result, the locking lever 35 is quickly rotated to the winding stop position by the bias of the torsion spring 37. Therefore, before the shutter drive lever 36 is rotated toward the release completion position by the urging force of the torsion spring 37, the trailing protrusion 35d of the locking lever 35 rotates the locus of the rising protrusion 36c of the shutter driving lever 36. When the shutter drive lever 36 enters the inside, the shutter drive lever 36 is held at the charge position, and the state shown in FIG. 14 is obtained. In this state, the one end 35a of the locking lever 35 is inserted into the groove 34a of the winding stop cam 34, so that the rotation of the intermittent sprocket 29 following the film winding is prevented.

After the rewinding of the film is completed, the bottom lid of the camera body is opened and the photo film cartridge 11 containing the photo film 12 having been taken is taken out. At this time, the drive shaft 23 rotates in conjunction with the opening operation of the bottom lid,
The lid member of the cartridge 11 is rotated to the closed position. Since the lid member of the taken-out photographic film cartridge 11 is in the closed position, the taken photographic film 12 housed inside is not covered with light.

In the above-mentioned embodiment, the apparatus for transferring the film one frame by one rotation of the intermittent sprocket 29 is described. However, the present invention is not limited to this, and the film is transferred one frame by one half rotation of the intermittent sprocket. The film feeding device may be used. In this case, as shown in FIG. 19, two pairs of teeth 27a, 27b arranged at a short interval L1 are provided, respectively, a wheel moving member 91 protruding from the circumferential surface at a position 180 ° apart from each other, The sprocket 90 may be constituted by the rubber band 92 exposed on the circumferential surface of the wheel moving member 91 except between the pair of teeth 27a and 27b. When such an intermittent sprocket 90 is used in a film feeding device, two shutter charge cams for pushing the shutter drive lever 36 to the charge position by half rotation of the intermittent sprocket 90 are provided at positions separated by 180 ° on the circumference. There is a need. Further, as the film winding stopping means, a groove is formed at a position 180 ° apart on the circumferential surface of the winding stopping cam 34 so that the one end 35a of the locking lever 35 is locked by half rotation of the intermittent sprocket 90. It is necessary to provide one.

[0062]

As described above, according to the present invention,
A wheel-moving member having a pair of teeth that engage with a pair of perforations arranged at short intervals, and a ring-shaped member that is arranged so as to be exposed on the outer peripheral surface of the wheel-moving member with the pair of teeth exposed to the outside. Since the elastic film is provided, the frictional force between the elastic film and the photo film is large in the section where the pair of perforations and the pair of teeth arranged at a short interval are not engaged, so the transfer force of the photo film is rotated. It can be reliably transmitted to the member. Further, in the invention of claim 2, since the elastic body having a circular cross section is used, the contact area with the photographic film is reduced, and when the preceding tooth of the pair of teeth comes into contact with the photographic film, the photograph is taken. The slip caused between the film and the film becomes easy.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a photographic film cartridge with the photographic film pulled out from the cartridge.

FIG. 2 is a horizontal sectional view showing an embodiment of a sprocket using a rubber band having a rectangular section.

FIG. 3 is an exploded perspective view of the sprocket shown in FIG.

FIG. 4 is a central cross-sectional view of the sprocket shown in FIG.

FIG. 5 is an exploded perspective view showing an embodiment of a sprocket using a rubber band having a circular cross section.

6 is a horizontal sectional view of the sprocket of FIG.

7 is a central vertical cross-sectional view of the sprocket shown in FIG.

8 is a central cross-sectional view of the sprocket of FIG.

9 is a perspective view showing an outline of a film feeding device using the sprocket described in FIG.

FIG. 10 is a perspective view showing an outline of a film winding and film rewinding mechanism.

FIG. 11 is a circuit diagram showing an electrical outline of a film feeding motor.

FIG. 12 is a timing flowchart for feeding a film.

FIG. 13 is an explanatory view showing an initial state of the intermittent sprocket and the counter means.

FIG. 14 is an explanatory diagram showing an initial state of film winding stopping means, shutter charging means, and the like.

FIG. 15 is an explanatory diagram showing a state after the shutter release of the film winding stopping means and the shutter charging means is completed.

FIG. 16 is an explanatory diagram showing a state in which the rotation of the intermittent sprocket is stopped in a state in which the preceding tooth comes into contact with the photographic film and then slips to allow the transfer of the photographic film.

FIG. 17 is an explanatory diagram showing states of the intermittent sprocket and the counter means when the first frame is set in the aperture.

FIG. 18 is an explanatory diagram showing states of the film winding stopping means and the shutter charging means when the film rewinding operation is performed.

FIG. 19 is a plan view showing another embodiment of the sprocket that feeds one frame of film by rotating it half way.

[Explanation of symbols]

 1,29,90 Sprocket 2,27,91 Wheel moving member 3,28,92 Rubber band 10 Photo film Patrone 11 Patrone 12 Photo film 14,16 Perforation 27a, 27b A pair of teeth

Claims (4)

[Claims] 1. A sprocket for detecting a one-frame feeding length of a photographic film having perforations alternately arranged at two kinds of intervals, wherein a pair of perforations arranged at a short interval among the perforations. It has a pair of teeth that engage with each other, and when the pair of perforations moves, the preceding tooth of the two teeth comes into contact with the photographic film and the rotation following the film winding is prohibited. Allows the photographic film to be transported while slipping on the circumferential surface until the tooth engages with the corresponding perforation, and rotates a predetermined amount when the following tooth engages with the corresponding perforation. The film is stopped and the rotational force obtained while the pair of teeth are engaged with the pair of perforations is applied to the shear force against the bias of the spring. A sprocket comprising: a wheel moving member that transmits the charge, and a ring-shaped elastic body that is disposed so as to be exposed on the outer peripheral surface of the wheel moving member with the pair of teeth protruding outward. . 2. The sprocket according to claim 1, wherein the elastic body has a circular cross section. 3. A sprocket used for securing one frame feed of a photographic film by a camera, and a wheel moving member having a pair of teeth on its outer circumference, and the wheel with the pair of teeth protruding to the outside. A sprocket characterized by comprising a ring-shaped elastic body exposed and arranged on the outer peripheral surface of the moving member. 4. A camera using a photographic film in which two perforations are arranged at a narrow interval for each frame feeding length, wherein a wheel provided with a pair of teeth engaging with the two perforations arranged at a narrow interval. A moving member and a ring-shaped elastic member that is arranged to be exposed on the outer peripheral surface of the wheel moving member in a state where the pair of teeth are projected to the outside. A sprocket having a frictional rotation region in which it is frictionally engaged and driven to rotate, and an engagement rotation region in which the two teeth engage with the perforation to be driven to rotate, and a sprocket driven in the winding direction of the film. A shutter charge mechanism that performs shutter charge in conjunction with the rotation of the sprocket while the sprocket rotates in at least a part of the engagement rotation range when the sprocket rotates. Camera, characterized in that it includes.