JPS6042466B2 - Photographic film trailing edge detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for detecting the trailing edge of photographic film pulled from a spool.

Conventionally, when the photographic film is pulled out from the spool and spliced, the trailing edge cut is performed by activating a trailing edge detection switch by the tension when the photographic film is completely pulled out from the spool, and using a signal from the trailing edge detection switch. A method has been adopted in which the rear end cutting means is activated at this time.

However, if there is some sort of problem with the photographic film, the film will not unravel smoothly from the spool, and tension will be applied while it is being pulled out, resulting in the problem that the photographic film will be cut midway through, although this is an extremely rare problem. SUMMARY OF THE INVENTION An object of the present invention is to provide a rear end detection device for a photographic film that eliminates the trouble of cutting the photographic film midway due to tension being applied during the withdrawal.

The above object of the present invention is to provide a device for detecting the trailing edge of a photographic film pulled out from a spool, which detects that the spool moves due to the tension applied to the spool when the trailing edge of the photographic film is pulled out from the spool. a first trailing edge detecting means; and a second trailing edge detecting means for detecting passage of a trailing edge of the photographic film by movement of a spool for which the first trailing edge detecting means detects the trailing edge. This is achieved by a photographic film trailing edge detection device characterized by the following.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a schematic plan view showing a state in which the photographic film 1 is completely pulled out from the cartridge, and FIG. 2 is a side sectional view thereof.

Referring to FIGS. 1 and 2, the rear end 2 of the photographic film is fixed to the spool winding core 3 of the cartridge, and the photographic film is pulled onto the substrate "P" by a film winding device (not shown).
” and in the direction “A” shown in FIG. 1. The first rear end detection means 5 includes a rotary lever 8 having guide rods 6 and 7 extending in the horizontal direction, and a switch 9.

This rotating lever 8 is spring-biased in the RBJ direction shown in FIG. 2 with a pin 10 as a fulcrum. On the other hand, the rotating lever 8
When the rear end is rotated in the RcJ direction shown in FIG. 2, the switch 9 is turned on and a first rear end detection signal is generated. The flange portion 11 of the spool winding core 3 of the cartridge is supported in contact with the guide rods 6, 7 of the rotating lever 8,
When tension is applied to the photographic film 1, R as shown in FIG.
It is supported movably in the DJ direction. The second trailing edge detection means 12 is preferably an optical detection device.

The second rear end detection means 12 is composed of a light emitter 13 and a light receiver 14, and infrared rays are used as light for rear end detection. In FIG. 3, the optical path 15 of the emitter 13 and the receiver 14 is shown on the back side of the rear end of the film.
The second detection means is arranged at a position away from the running path of the perforations, for example, at a position where it passes between the outer edge of the perforation 4 and the side edge of the photographic film. Of course, it may be placed at a position inside the perforation 44 for detection. Perforation 4 like this
By detecting the rear end at a position away from the running path,
Even if there are skipped stitches due to perforation damage, etc., the rear end can be reliably detected. When the spool core of the photographic film 1 advances to a predetermined position due to the winding tension, the light from the light projector 13 is received by the light receiver 14 and outputs a second detection signal to the trailing edge detection circuit 20. It is configured like this. The operation of the photographic film 1 constructed as above will be explained with reference to the block diagram shown in FIG.

When the photographic film 1 is completely pulled out as shown in FIGS. 1 and 2, the photographic film 1 is still pulled in the direction of the arrow RAJ by the unillustrated winding device, and the spool core 3 is also pulled out by a predetermined distance RAJ. Rc. The film is rotated in the J direction to generate a first detection signal from the trailing edge detection switch 9 and output to the film trailing edge determination circuit 16. At the same time, if the photographic film 1 is completely pulled out, the second trailing edge detection means 1
The second light receiver 14 receives the infrared rays from the projector 13 and outputs a second detection signal to the switch rear end determination circuit 16 via the rear end detection circuit 20 . When the signal is input to the film trailing edge determination circuit, the cutter drive circuit 17 is activated to drive the cutter 18 to cut a predetermined trailing edge of the photographic film. On the other hand, if the photographic film wound around the spool core is not unraveled smoothly and some kind of tension is applied to the photographic film, an alarm 19 is activated from the film trailing edge determination circuit 16, thereby preventing the film from being accidentally cut. There isn't. The trailing edge detection device of the present invention can be used, for example, with a photographic film splicer (a special patent application by the same applicant) that sequentially splices photographic films stored in a cartridge into a long film in order to develop the photographed film. It is also possible to bring about a remarkable effect by applying it to the Haku No. 57-441).

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of a photographic film trailing edge detection device according to the present invention, FIG. 2 is a schematic side sectional view of the device, FIG. 3 is an enlarged explanatory view of the back side of the film, and FIG. 4 is a block diagram of the device. It is a diagram. Codes in the figure: 1... Photographic film, 2...
・Photographic film fixed end, 3...Spool winding core,
4... Perforation, 5... First rear end detection means, 6, 7... Guide rod, 8...
... Rotating lever, 9... Switch, 10...
... Zen, 11... Flange part, 12...
...Second rear end detection means, 13...Floodlight, 1
4... Light receiver, 15... Optical path, 16.
...Film trailing edge determination circuit, 17...Cutter drive circuit, 18...Cutter, 19...
...Alarm, 20...Rear end detection circuit.

Claims (1)

[Claims] 1. A device for detecting the trailing edge of a photographic film pulled out from a spool, which detects that the spool moves due to the tension applied to the spool when the trailing edge of the photographic film is pulled out from the spool. a first trailing edge detecting means; and a second trailing edge detecting means for detecting passage of a trailing edge of the photographic film by movement of a spool for which the first trailing edge detecting means detects the trailing edge. A photographic film trailing edge detection device characterized by: 2. The rear edge of the photographic film according to claim 1, wherein the second trailing edge detection means detects passage of the trailing edge of the photographic film at a position that is out of the travel path of the perforations of the photographic film. Edge detection device.