JPS62115136A - Film feeding confirming device for camera - Google Patents

Abstract

PURPOSE:To confirm feeding of a film without keeping user's eyes off a finder by turning on and off a light emitting body in the finder in accordance with the feeding operation of the film. CONSTITUTION:When the film is loaded correctly, a film detecting switch 31 is turned on because a detecting pin 34 is depressed. When a sprocket 15 is rotated to turn on a feed switch 28, an LED 32 is lit. If the switch 28 is turned on twice per one rotation of the sprocket 1, the LED is flickered twice by one winding operation (corresponding to one frame of the film). Since it is flickered in the finder, a photographer can confirm feeding of the film without keeping his eyes off the finder. Though the rotation direction of the sprocket 15 is reverse in case of rewinding, feeding of the film is confirmed similarly because the LED 3 is flickered while the sprocket 15 is rotated.

Description

TECHNICAL FIELD The present invention relates to a film feed confirmation device for confirming film winding and rewinding of a camera.

"Prior art and its problems" Conventionally, this type of film feed confirmation device has a rotating member (advance) that comes into contact with the film on the rear lid of the camera.
A device in which the rotation of this rotating member that rotates as the film is fed can be visually observed from outside the camera is generally used. However, with cameras that automate film winding, when you look through the viewfinder and press the shutter, winding begins continuously, so to check whether or not the film is being advanced, you need to use the shirt screen. After releasing the camera, you must immediately take your eyes off the viewfinder and look at the rotating parts. This action is not an action that can be easily performed when taking pictures with a camera, and the original purpose of taking pictures, such as determining the composition, may be sacrificed.

Furthermore, when photographing at twilight or at night, it is difficult to confirm the rotation of the rotating member. Furthermore, mechanically, since the rotating member is in contact with the film, the film is easily damaged, and if the urging force of the rotating member toward the film is too strong, the film may have poor flatness or the rotating member may creak (abnormal noise). ) occurs, and if it is too weak, there is also a mechanical problem in that the rotating member will malfunction.

``Object of the Invention'' In view of the above-mentioned problems of the conventional device, the present invention has been devised to make it possible to check the film feeding in a natural photographing state while looking through the viewfinder and even at night, and by using a rotating member. It is an object of the present invention to obtain a film feeding confirmation device capable of eliminating problems.

``Summary of the Invention'' The present invention was developed based on the idea that a light emitting body for confirming film feeding is provided in the viewfinder, and this light emitting body blinks in conjunction with film feeding. In order to make the body blink, it features a feed confirmation switch that turns on and off in conjunction with the rotation of the sprocket that meshes with the perforation.

"Embodiments of the Invention" The present invention will be described below with reference to illustrated embodiments. In the camera body 11, a cartridge chamber 13 and a take-up spool 14 are arranged on the left and right sides of the screen opening 12, and a sprocket 15 faces the lower side of the screen opening 12. Sprocket 15 is
Depending on the camera, it may be provided at a different position.

As is well known, this sprocket 15 has teeth 15a that mesh with perforations P of the film F, and is rotated by a winding mechanism. Further, when the film F is rewound to the cartridge 16, it is rotated by the film F. 4 and 5 show an example of a winding mechanism for the sprocket 15, in which the sprocket 15 rotates via a main gear 17, an interlocking gear 18, and a sprocket gear 19 supported by the camera body 11. The main gear 17 has a pawl 20 that engages and disengages from the clutch 1, and when the film winding is complete,
The sprocket 15 is designed to stop at a certain position shown in Figure tiS5. This mechanism is a mechanism for preventing the cutting line C and the perforation P from coinciding with each other when cutting the developed film along the cutting line C in the middle of the photographing screen 21 (FIG. 3). In addition, since eight perforations P are provided per frame of the photographing screen 21, and eight teeth 15a are provided on the sprocket 15,
One rotation of the sprocket 15 feeds the film one frame at a time.

A brush 24 is fixed to the above sprocket 15 as shown in FIGS.
A pair of lands 26 that are turned on and off by these 24 are fixed to the substrate 25 fixed to the side. The brush 24 and the land 26 constitute a feed confirmation switch 28, and the brush 24 does not come into contact with the land 26 when the block 15 is stopped with film winding completed. On the other hand, for film winding, the block is 15
When the brush 24 rotates once, the brush 24 brings the pair of lands 26 into conduction twice.

A battery 30, a film detection switch 31, and an LED (light emitter) 32 are connected in series to the pair of lands 26. 33 is another camera function circuit such as an exposure control circuit, which is supplied with power from the battery 30. FIG. 6 is a simplified diagram of the second power supply circuit.

The film detection switch 31 is located at the upper part of the screen opening 12, and has a detection pin 3 that slightly protrudes from the running surface of the film F.
4 is turned on when pressed by film F. LED3
2 is provided at a visible position within the finder 35.

Therefore, in this apparatus having the above configuration, when the film F is loaded correctly, the detection bin 34 is pushed and the film detection switch 31 is turned on, and when the film feed confirmation switch 28 is turned on by rotating the block 15, the LED 3
2 lights up. In this example, the feed confirmation switch 28 is turned on twice per rotation of the subblock l-15, so the LED 32 flashes twice for each -times (-frame) hoisting operation. Become. This flashing is caused by the viewfinder 35.
Since this occurs within the camera, the photographer can check the film feeding without taking his or her eyes off the viewfinder 35.

When winding is completed, the sprocket 15 is stopped by the locking pawl 20 at a position where the brush 24 is not in contact with the land 26. Therefore, unnecessary consumption of the battery 30 can be prevented.

Furthermore, during rewinding, the direction of rotation of the sprocket 15 is reversed, but since the LED 32 blinks while the sprocket 15 is rotating, this can be confirmed in the same way.

In the illustrated example, the film detection switch 31 detects the film F.
It is turned on by the detection pin 34 that comes into contact with the sensor. This configuration is most preferred for complete detection of film loading. However, more simply, the loading of the film may be detected by a detection pin that is pressed when the cartridge 16 is loaded into the cartridge chamber 13. Furthermore, the DX code (film information code such as ASA) provided on the outer surface of the cartridge 16
It is also possible to detect film loading using the reading circuit. According to this configuration, a mechanical switch mechanism for detecting film loading is not required. Further, the film detection switch 31 is intended to prevent unnecessary consumption of the battery 30 when the sprocket 15 is rotated and the feed confirmation switch 28 is turned on without film F being loaded. This can be omitted if this purpose can be achieved by means of.

"Effects of the Invention" As described above, the film feed confirmation device of the present invention utilizes a sprocket that always rotates in conjunction with the film feed operation, and has a feed confirmation switch that turns on and off in conjunction with the rotation of this sprocket. Since the light emitter placed inside the viewfinder blinks, you can check the film feeding without taking your eyes off the viewfinder. In other words, since the photographer can check the film advance in a natural state during shooting, he or she can concentrate on shooting. Furthermore, since it uses a luminous object, it can be seen reliably even at night. Since there is no rotating member in contact with the film, the mechanical structure can be simplified, there is no need to consider the durability of the film, and any negative effects on the flatness of the film can be eliminated. can.

[Brief explanation of drawings]

Fig. 1 is an implementation wiring diagram of an embodiment of the film feed confirmation device according to the present invention, Fig. 2 is a rear view of the camera body with the back cover removed, and Fig. 3 is a rear view of the camera body with the film loaded. 4 is a front view of the sprocket drive mechanism, FIG. 5 is an open plan view, and FIG. 6 is a simplified electric circuit diagram of the device of the present invention. F...Film, P...Perforage 1, 11
... Camera body, 12... Screen opening, 13... Patrone chamber, 14... Take-up spool, 15... Sprocket, 15a... Teeth, 16... Patrone, 2
4... Brush, 26... Land, 28... Feeding confirmation switch, 30... Battery, 32... LED
(light emitter), 34...detection pin, 35...finder. Figure 1

Claims (3)

[Claims] (1) A camera characterized in that a light-emitting body is installed in the viewfinder of the camera, and the light-emitting body is made to blink by a feeding confirmation switch that is turned on and off in conjunction with the rotation of a sprocket that engages with the perforations of the film. Film feed confirmation device. (2) In claim 1, the camera further includes a film detection switch that is turned on when film is loaded, and the film detection switch and the feed confirmation switch are connected in series. Feeding confirmation device. (3) The film feed confirmation device for a camera according to claim 1 or 2, wherein the feed confirmation switch is turned off at a sprocket stop position when film winding is completed.