JPH11119331A - Film holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film holder capable of efficiently preparing photographing, just after an exchange of films. SOLUTION: When a film setting switch 50 is turned on, a setting signal is fed from a setting signal generating circuit 45. A CPU 40 drives a motor 23, to start the feeding of a film 21, when the setting signal is inputted and then, stops the driving of the motor 23, when the first photographic picture frame of the film 21 faces an exposure aperture 26. These series of control operations are individually executed in a film holder 20 and any control is not received from a camera CPU 47. Thus, for instance, when the exchange of films and photographing are executed in such a manner that they are allocated to an assistant and a cameraman, the first frame is set just after the assistant exchanges the film, to enable preparations for a photographing possible state, so that the cameraman immediately takes a photograph, just after the film holder 20 is loaded in the camera main body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film holder used by being mounted on a camera body.

[0002]

2. Description of the Related Art As a camera having a large screen size for a commercial photograph, a camera using a medium-size film and mounting a film holder on a camera body is used. In this camera, a photographing lens with a built-in shutter and a film holder containing a roll film are mounted on the front and back of the camera body, so that the photographing lens can be exchanged according to a photographing environment and a photographing scene. ing.

The film holder is provided with a motor as a drive source for feeding the film, and a microcomputer for controlling the driving and stopping of the motor, separately from the camera body. When the film holder is mounted on the camera body, film feeding control is performed based on an electric signal from the camera body.

The film holder is provided with an exposure opening for defining an exposure range on the film, and a flat light-shielding cover is fitted into the exposure opening so as to be able to be pulled out and inserted freely. When the light-shielding lid is pulled out, the exposure opening is opened, and the subject light that has passed through the taking lens is exposed on the film surface. When the light-shielding lid is inserted, the optical path for photographing is shut off, so that the light-shielding property in the film holder is maintained.

[0005] Commercial photographs are taken by professional photographers in a studio. At this time, the exchange of the film during the photographing is generally performed by an assistant so that the photographer can concentrate on the photographing. The replacement of the film is performed with the light-shielding lid inserted and the film holder removed from the camera body. The photographer receives the film holder containing the new film from the assistant, attaches it to the camera body, and shoots.

[0006]

However, as described above, since the film feed control is performed based on the electric signal from the camera body, after the film holder is mounted on the camera body. Otherwise, the first frame of the film cannot be set inside the exposure aperture. For this reason, since the photographer must set the first frame of the film by operating the camera after exchanging the film, the photographing cannot be quickly performed.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and has as its object to provide a camera film holder capable of efficiently preparing for photographing immediately after film exchange.

[0008]

In order to achieve the above object, a film holder of the present invention comprises a film feeding mechanism for feeding a film, a motor for driving the film feeding mechanism, and an external device. It has a switch part that can be operated, a set signal generating means for sending a set signal when this switch part is operated, and starts a film feeding by driving a motor when the set signal is sent, Thereafter, a feed control means for stopping the driving of the motor when the first photographing frame of the film faces an exposure opening formed on the feed path of the film is incorporated.

[0009]

FIG. 3 shows the structure of a single-lens reflex camera with a lens shutter embodying the present invention.
The camera 10 is configured by mounting a lens unit 12 and a film holder 20 on the front and back of a camera body 11. A guide tube 13 is provided at the bottom of the camera body 11 so as to protrude forward, and a feeding unit 14 is attached to the guide tube 13. The feeding unit 14 is provided movably in the front-rear direction along the guide tube 13.

[0010] Inside the camera body 11, a mirror 15 and a light shielding plate 16 are incorporated. The mirror 15 has a descending position that enters the photographing optical path as shown by a solid line in the drawing,
As shown by a two-dot chain line, the camera is movably provided between an ascending position and a retracted position from the imaging optical path. The light-shielding plate 16 follows the movement of the mirror 15, and closes the opening 17 formed on the rear surface of the camera body 11 when the mirror 15 is at the lowered position, and opens the opening 17 when the mirror 15 is at the raised position. The mirror 15 and the light shielding plate 16 are instantaneously moved to the ascending position side when the shutter blade, which will be described later, is opened by the release operation, to open the photographing optical path to the film holder 20.

The lens unit 12 has a built-in photographic lens 18 and shutter blades 19, and
4 and attached to the front of the camera body 11. Since the feed-out unit 14 is provided so as to be movable in the front-rear direction along the guide tube 13, the lens unit 12 is movable in the optical axis direction, whereby the focus can be adjusted.

The film holder 20 accommodates a band-shaped film 21, a film feeding mechanism 22 for feeding the film 21, a motor 23 for driving the film feeding mechanism 22, and a film A spool 24 for winding the exposed portion is incorporated. A back cover 20a is provided on the back of the film holder 20, and the back cover 20a is opened to release the film 21a.
Is loaded and unloaded.

The film 21 is stored in a state wound around a spool 25 (see FIG. 1). Film 21
Is provided with a light-shielding strip-shaped leader paper (not shown) at the tip end thereof, and covers the outermost periphery of the film 21 wound around the spool 25. When the film 21 is loaded into the film holder 20, the leading end of the leader paper is pulled out and locked on the spool 24. The film 21 is fed from the spool 25 side to the spool 24 side by the driving of the film feeding mechanism 22 every time an image is taken.

An exposure opening 26 for defining an exposure range for the film 21 is formed on the front surface of the film holder 20.
Is mounted on the camera body 11 so as to face the opening 17.
A flat light-shielding lid 27 is fitted into the exposure opening 26 so as to be freely drawn out and inserted. When the light-shielding cover 27 is pulled out, the exposure opening 26 is opened, and the photographing light passing through the photographing lens 18 is exposed on the film 21. Further, when the light-shielding lid 27 is inserted, the optical path for photographing is blocked, and the light-shielding property in the film holder 20 is maintained. Thus, when the film holder 20 is detached from the camera body 11, the exposure of the film 21 by external light that has entered through the exposure opening 26 is prevented.

As shown in FIG. 4, the film holder 20
A liquid crystal display panel 28 for displaying the number of films and displaying a warning, and a group of operation buttons 30 are provided on the upper surface of the camera. A cover 29 is placed on the upper surface of the operation buttons constituting the operation button group 30, so that the operation buttons are not erroneously operated.

FIG. 1 shows an electrical configuration inside the film holder 20. As shown in FIG. The CPU 40 for controlling the electric signals in the film holder 20 includes a liquid crystal display panel 28.
, A light-shielding lid detection circuit 42, a film detection circuit 43, a motor driver 44, and a set signal generation circuit 45 are connected. When the film holder 20 is mounted on the camera body 11, the CPU
40 is connected via a communication control circuit 46 to a camera CPU 47 for controlling electric signals in the camera body 11.

A switch 48 is connected to the light shielding cover detecting circuit 42. The switch 48 is turned on when the light-shielding lid 27 is inserted into the film holder 20 and the exposure opening 26 is completely shielded, and turned off when the light-shielding lid 27 is pulled out. The light-shielding lid detection circuit 42 outputs a “close signal” when the switch 48 is in an ON state and an “open signal” when the switch 48 is in an OFF state.
To the CPU 40.

A sensor 49 is connected to the film detection circuit 43. The sensor 49 includes a light projector 49a for irradiating the film 21 with uniform light, and a light receiver 49b for receiving light reflected on the film surface and outputting a signal of a level corresponding to the light amount. Is disposed in the vicinity of the spool 24.

Here, immediately after the film 21 is loaded in the film holder 20, the leader paper faces the front of the sensor 49, so that the light emitted from the projector 49a is reflected by the leader paper surface and received. Incident on the vessel 49b. When the feeding of the film 21 is started and the film 21 reaches the front of the sensor 49, the light reflected on the film surface enters the light receiver 49b. Since the light reflectance differs between the leader paper surface and the film surface, a signal of a level corresponding to each reflectance is output from the light receiver 49b. Therefore, whether or not the film surface is located on the front surface of the sensor 49 can be identified based on the level of the output signal from the light receiver 49b. In general, a leader paper having a light-shielding property has a lower reflectance than a film surface, so that when the leader paper is facing the front of the sensor 49, a LOW level signal is generated, and when the film surface is facing. An HI level signal is output from the light receiver 49b.

The film detection circuit 43 outputs the "H signal" when the level of the output signal from the light receiver 49b is at the HI level, and outputs the "H signal" when the level of the output signal from the light receiver 49b is LOW.
When the level is at the level, an “L signal” is sent to the CPU 40.

A film set switch 50 is connected to the set signal generation circuit 45. The film set switch 50 is provided so as to be exposed on the upper surface of the film holder 20, and constitutes a part of the operation button group 30 described above (see FIG. 4). The set signal generation circuit 45 outputs the “set signal” when the film set switch 50 is turned on.
To the CPU 40.

The CPU 40 displays the number of films, displays a warning, and the like on the liquid crystal display panel 28 via a liquid crystal driver 41, and displays the motor 23 via a motor driver 44.
Control of driving and stopping of the motor. Set signal generation circuit 4
When the set signal is transmitted from the CPU 5, the CPU 40
The film 21 is fed and the first photographing frame is
6 on the back. Each time the shutter blade 19 is opened and closed by the release operation,
A “frame feed signal” is input from the camera CPU 47.
When a frame advance signal is input to the CPU 40, the CPU 40
Feeds the film 21 by a predetermined length and positions the next photographing frame on the back of the exposure opening 26.

Next, the procedure for positioning the first photographing frame of the film 21 on the back of the exposure aperture 26 will be described with reference to the flowchart of FIG. When the film set switch 50 is turned on, a set signal is input to the CPU 40 from the set signal generation circuit 45. First, the CPU 40 checks an output signal from the light shielding cover detection circuit 42. When the “close signal” is output from the light shielding cover detecting circuit 42, the CPU 40 drives the motor 23 via the motor driver 44 to feed the film 21 from the spool 25 to the spool 24. .

When the entire leader paper portion is wound on the spool 24 and the leading end of the film 21 reaches the front of the sensor 49, the output signal level of the light receiver 49b becomes LOW.
Level to the HI level, and the film detection circuit 43
Also changes from the “L signal” to the “H signal”. The output signal from the film detection circuit 43 is "H signal"
At the moment, the CPU 40 stops driving the motor 23. Thus, the first photographing frame of the film 21 is positioned on the back of the exposure opening 26.

On the other hand, when the output signal from the light-shielding cover detecting circuit 42 is an "opening signal", it means that the exposure opening 26 is not completely shielded, so that the CPU 40 does not feed the film 21.

When storing the film 21 in the film holder 20 constructed as described above, first, the light-shielding cover 27 is inserted into the film holder 20, and then the film holder 20 is removed from the camera body 11. Next, the back cover 20a of the film holder 20 is opened, the film 21 wound around the spool 25 is loaded, and the leading end of the leader paper covering the outermost periphery of the film 21 is pulled out and locked on the spool 24. Then, when the back cover 20a is closed again, the loading of the film into the film holder 20 is completed.

When the loading of the film is completed, the film 21
Is positioned on the back of the exposure aperture 26,
The film 21 is prepared to be ready for exposure. When a film set switch 50 provided on the upper surface of the film holder 20 is turned on, the motor 23 is driven and the film 21 is fed from the spool 25 side to the spool 24 side. When the entire leader paper portion is wound around the spool 24 and the leading end of the film 21 reaches the spool 24, the drive of the motor 23 is stopped and the feeding of the film 21 is also stopped. Thus, the first photographing frame of the film 21 is positioned on the back of the exposure opening 26.

At this time, for example, when the insertion of the light shielding cover 27 is incomplete and the exposure opening 26 is not completely shielded,
Since the output signal from the light shielding cover detecting circuit 42 is an "opening signal", the film 21 is not fed. Thus, the film 2 is exposed to the external light that has entered through the exposure opening 26.
1 is prevented from being carelessly exposed.

Thereafter, if the film holder 20 is mounted on the back of the camera body 11 and the light-shielding cover 27 is pulled out, the photographing can be performed immediately.

When the shutter blade 19 is opened and closed by a release operation, a “frame feed signal” is input to the CPU 40 from the camera CPU 47. As a result, the motor 23 is driven, the film 21 is fed, and the exposed portion is wound around the spool 24. When the film 21 is fed by one frame, the driving of the motor 23 is stopped, and a new photographing frame of the film 21 is positioned on the back of the exposure opening 26.

[0031]

As described above, according to the film holder of the present invention, the set signal generating means for transmitting the set signal when the switch is operated, and the motor for driving the motor when the set signal is transmitted. To start film feeding.
After that, since the built-in feed control means stops the motor drive when the first frame of the film faces the exposure opening, the film holder alone can be used without any control from the camera body. The first frame of the film can be set. Therefore, for example, when performing film exchange and photographing by division of labor between the assistant and the photographer, such as when taking a commercial photograph, the assistant sets the first photographing frame immediately after exchanging the film and allows exposure. It is possible to prepare for the state. This allows the photographer to immediately take a picture after attaching the film holder to the camera body.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an electrical configuration of a film holder of the present invention.

FIG. 2 is a flowchart showing a procedure for positioning a first photographing frame of a film on a back surface of an exposure aperture.

FIG. 3 is a schematic diagram showing a configuration of a camera using the film holder of the present invention.

FIG. 4 is a schematic view showing an upper surface of a film holder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Camera main body 20 Film holder 21 Film 23 Motor 26 Exposure opening 27 Shield lid 40 CPU 45 Set signal generation circuit 50 Film set switch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kotobuki Hamada 3-13-45 Izumi, Asaka-shi, Saitama Fuji Photo Film Co., Ltd. (72) Inventor Tokuji Sato 3-13-45 Izumi, Asaka-shi, Saitama Fuji Photo Inside Film Co., Ltd.

Claims (1)

[Claims] A film feed mechanism for mounting the roll film and feeding the film; a motor for driving the film feed mechanism; A set signal generating means for sending a set signal when the switch is operated, and driving the motor when the set signal is sent to feed the film. And a feed control means for stopping the driving of the motor when the first photographing frame of the film starts and thereafter the exposure frame formed on the feed path of the film is confronted.