JPH0473131B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention imprints data such as the date, time, or shooting location (hereinafter referred to as "data") onto a photographic photosensitive film (hereinafter referred to as "film") in response to the winding motion of the film. The present invention relates to a method for detecting a position signal of a film of a camera with a data imprinting function.

With advances in electronics technology, cameras have come to be provided with various useful additional functions.
One of these functions is the ability to superimpose data on images of landscapes and people, and is particularly useful for family records and travel photos.

FIG. 4 is a conceptual diagram of position detection of film movement by a rotary encoder of a conventional camera with a data imprinting function, and shows the film and camera body of the conventional camera. In the figure, 1 is a film, on which a photographic image of a landscape or the like is recorded from the front, and at the same time, data is temporarily stored in accordance with the timing of the shutter 2. The temporarily stored data is moved one frame by the film winding operation of the film rewapper 4. Single-digit LEDs then emit light sequentially to create an imprint each time the film is moved. The timing of the light emission of this LED is determined by the amount of movement of the film 1.

Rotary encoder 5 is directly connected to sprocket 6. After photographing, a photographer winds up the film 1 using the film winding lever 4. As a result of this operation, the film winding gear 7 interlocked with the sprocket 6 engages with the perforation 8 of the film 1, thereby moving the film 1 one frame. With this operation, the rotary encoder 5 connected to the sprocket 6 rotates around the sprocket 6. In other words, the film 1 rotates by the amount that it moves one frame. In general, the rotation of the sprocket 6 is one rotation per movement of the film 1 one frame. For this reason, the rotary encoder 5 is designed to have the resolution of imprinted characters in one rotation. As a result, several film position signals are obtained by setting the rotary encoder 5.

Figure 3 is a conceptual diagram of position detection of film movement using a micro switch in a conventional camera with data imprinting function, showing the conventional detection part, and is an enlarged view of a part of the film position detection mechanism attached to the sprocket. It is a diagram. In the figure, 7 is a film winding gear that is interlocked with a sprocket. Reference numeral 9 denotes a film position detection lever, which is interlocked with a micro switch 10. When the shutter is pressed and the film winding mechanism operates, the sprocket, which moves synchronously, rotates, and the sprocket 7 rotates and meshes with the gears of the sprocket. The perforation of the film moves and the film is wound. At this time, the film position detection lever 9 is engaged with the sprocket 7, and is pushed up each time the sprocket rotates, thereby interlocking with the film position detection lever 9. As a result, the microswitch 10 generates a film position signal.

As mentioned above, conventional cameras with a data imprinting function use a rotary encoder method or a micro switch method for detecting the position of film movement, but both have drawbacks.

First of all, the rotary encoder has the following drawbacks. The first problem is the shape.
The rotary encoder has LEDs as an internal structure.
There are rotary encoders that use phototransistors and have slits corresponding to the resolution between them, and those that have contacts corresponding to the resolution and detect by contact with brushes, but all types of rotary encoders end up being large in size. Since this large rotary encoder is extended and connected to the bottom of the sprocket and rotated to detect the film position signal, the bottom of the camera body becomes large. Also, since a rotary encoder must be attached to the camera body, the camera body must be significantly redesigned. Generally, the main body of the data imprinting function of a camera with a data imprinting function is located on the back cover side of the camera. It is not preferable to install parts for data imprinting on the camera body side in order to detect film position signals.
It goes without saying that it would be better to have the imprint function only on the back cover side. Furthermore, the cost of the rotary encoder is extremely high due to its structure, making it unsuitable for cameras with data imprinting functions aimed at low prices. This has hindered the spread of cameras with this type of data imprinting function.

Next, the disadvantages of the microswitch method are as follows. Unlike detection using a rotary encoder, there is no need to set up detection parts on the camera body side, and all detection parts can be installed on the back cover side. Also, the shape is not very large. But it's not reliable. The higher the resolution of a microswitch, the more chattering will occur. As a result, film position signal detection is unreliable due to chattering. Also, since it is a mechanical switch, it is not durable.

As described above, conventional film position detection methods include the rotary encoder method and the micro switch method, but in both cases, the detection methods have drawbacks.

The present invention has focused on this point and has solved these drawbacks of film position signal detection in conventional cameras by detecting film position signals using an LED phototransistor installed on the back cover side.

The film's perforation is used to detect the position of film movement, and the position signal necessary to imprint data is detected using infrared LEDs and phototransistors.

FIG. 1 is a structural diagram of the back cover of the camera according to the present invention. Furthermore, FIG. 2 is a diagram showing the relationship between the LED phototransistor and the perforation of the film. The main difference between the present invention and conventional film position signal detection is that an infrared reflective LED phototransistor is installed on the film presser 11 of the back cover on the side facing the film.

LED phototransistor 12, LED phototransistor 13, LED phototransistor 14,
The LED phototransistor 15 and the LED phototransistor 16 are of a reflective type that emit infrared light. A pair of LED and phototransistor are built into one package. The infrared light emitted by the LED is reflected by objects that can reflect it and returns. A phototransistor receives this light and detects that there is an object in front of it. on film
When the infrared light emitted from the LED hits the film, it reflects the infrared light. The present invention uses this principle.

When the photographer takes a picture and imprints the data,
First, point the camera at the subject and press the shutter. The data at this time is temporarily stored. Next, when the film is wound by the film winding lever, the data is imprinted.

Film position signal detection immediately after shooting is performed as follows. The LED phototransistor 12 is initially aligned with the perforation 17.
As a result, the infrared rays emitted from the LED are not reflected because there is no film on the top. Therefore, the phototransistor does not receive light and the LED phototransistor 1
2 does not output a signal. Next, since the LED phototransistor 13 is not aligned with any perforation, the infrared light emitted from the LED hits the film 1 and is reflected. Therefore, the phototransistor receives light and outputs a signal. LED phototransistor 14, LED phototransistor 1
5. Similar to the LED phototransistor 13, the LED phototransistor 16 has a film on the top, so a signal is output. In this manner, when detecting a film position signal immediately after photographing, only the LED phototransistor 12 does not output a signal, and all the remaining LED phototransistors output a signal. This is the film position signal condition before winding.
Next, the film is wound up by the film winding lever, and the film gradually moves. In other words, the perforation of the film moves. Then, a film comes over the LED phototransistor 12. LED as soon as it reaches the top
The infrared rays emitted from the film are reflected by the film. The phototransistor receives the light and outputs a signal. At this time, the upper part of the LED phototransistor 13 is aligned with the perforation 18 of the film. Therefore, no position signal is output from the LED phototransistor 13. In this way, the film moves while aligning and misaligning with the LED phototransistor and film perflation. This timing is detected as a film position signal. Five LED phototransistors are installed on the back cover, and each roll of film moves eight perforations. As a result, a total of 40 film position signals can be detected.

This results in the following advantages.

There is no need to provide a position detector for film movement on the camera body, so you can take pictures with just the back cover. For this reason, the camera body does not need to be made large. Furthermore, since the detection is performed by moving the film, the exact amount of film movement can be detected and there are no errors. The structure is very simple and the reliability is very good. In addition, by gradually shifting the position of the LED phototransistor and increasing the number of position detection points, the system can be used not only for cameras with an automatic winding mechanism with a constant winding speed, but also for manual winding type cameras where the winding speed is uneven. It is also possible to maintain high imprint quality. In particular, in the case of manual winding, not only is the winding speed not constant, but there are also cases where the winding is done in parts for one frame, but the present invention has high accuracy in detecting the film position, so it is suitable for such operations. It is also possible to imprint data without degrading the imprint quality.

The cost is low and it can also be used for data imprinting on low-priced cameras such as automatic cameras, helping to popularize cameras with data imprinting functions.

In the present invention, five LED phototransistors are installed in the back cover film holder, but the present invention is not limited thereto. If the number of installed units is increased, the number of film position signals per film winding will increase, and the resolution will further increase. Needless to say, if the number of installations is reduced, the number of film position signals will be reduced.

Furthermore, an LED phototransistor is a type in which a pair of an LED and a phototransistor are built into one element, but the invention is not limited thereto. Even if the LED and phototransistor are separate elements, they can be set so that they can emit and receive light.

Although the film movement position is detected at the time of film winding, the present invention is not limited thereto, and the film movement position may be detected in synchronization with the film unwinding.

As mentioned above, the film movement position can be detected using the LED phototransistor built into the back cover. This makes it possible to reduce the cost of the data imprinting function, improve the precision of detecting the position of film movement, and reduce the size of the film, and the effects are extremely significant.

In this example, an LFD was used as a light emitting element, and a phototransistor was used as a light receiving element.

[Brief explanation of the drawing]

Fig. 1 is a structural diagram of the back cover of the camera of the present invention;
The figure shows the relationship between LED phototransistor and film perforation. Figure 3 is a conceptual diagram of position detection of film movement using a micro switch in a conventional camera with data imprinting function, and Figure 4 is a conceptual diagram of position detection of film movement using a rotary encoder of a conventional camera with data imprinting function. be. 1... Film, 2... Shutter, 4... Film winding lever, 5... Rotary encoder, 6... Sprocket, 7... Film winding gear, 8... Perflation, 9...
...Film position detection lever, 10...Micro switch, 11...Film holder, 12...LED
Phototransistor, 13...LED phototransistor, 14...LED phototransistor,
15...LED phototransistor, 16...
LED phototransistor, 17...perflation, 18...perflation, 19...
...Perflation, 20...Perflation, 21...Perflation.

Claims (1)

[Claims] 1. In a camera with a data imprinting function that has a detection means for detecting the movement of the film when the film is wound and imprints data in synchronization with the output of the detection means, the detection means includes a plurality of light emitting elements and The light-emitting element and the light-receiving element pair are disposed on the back cover side of the camera and are arranged to face the perforation part of the film, and the light emitting element and the light receiving element are arranged so as to face the perforation part of the film. It is characterized in that only one pair of the element and the light-receiving element coincides with the perforation hole, and as the film moves, the arranged pairs of the light-emitting element and the light-receiving element sequentially coincide with the perforation hole. Camera with data imprint function.