JPS5816222A - Film feed confirmation device - Google Patents

Abstract

PURPOSE:To display a film feed state securely by detecting the film feed state electrically, and displaying the feed state on the display means of a data imprinting device. CONSTITUTION:The data display part 8 of a back cover is provided with display characters 9 for a date, etc., and a symbol 12 for feed confirmation. Normally, data to be imprinted on a film are displayed in display characters 9 and when film feeding is detected with a ball contact piece, the data display is ceased to flash a symbol 12 for feed confirmation. Once a signal B is inputted from a pulse detector 13, a feed confirmation mode is set and the date display is ceased while the feed confirmation symbol 12 is displayed. For this purpose, a signal from a counter 14 is only inputted to flash a symbol at a position which corresponds to the signal, thus confirming the film feeding easily and securely.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a film feeding system for a camera.

In cameras that use perforated film such as 65 mm film, various devices have been proposed for detecting the actual movement of the film and confirming its feeding. Such devices generally have a mechanism for detecting film advance and a display means inside the camera, but it is difficult to arrange these mechanisms and display means at appropriate positions in cameras with complex mechanisms. Sometimes it's my sister.

On the other hand, a camera is known which is a data imprinting device and is built into the back cover and has data display means on the outer surface of the back cover.

The present invention provides a means for electrically detecting the film feeding state using the perforations of the film and is provided in the back cover, and also allows the feeding state to be displayed using the display means of the data imprinting device described above. With this configuration, it is possible to obtain a device that eliminates space constraints within a conventional camera and allows the film feeding state to be easily checked by adding only a few members.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 is a cross-sectional view of the camera back cover near the feed detection section.
2 indicates a camera body, 2 indicates a back cover, and 6 indicates a data imprinting device built into the back cover. 4 is a film pressure plate attached to the back cover 2 via a plate spring or the like, as is well known. 6. 6/ is a ball contact piece held on the pressure plate, which is energized by springs 7 and 7' and closes the circuit when it is in contact with the camera body 1, and is a switch that opens when there is a film between it and the body. form.

4 al indicates an insulating layer that electrically insulates the ball and the pressure plate 4.

As shown in FIG. 2, the contact ball 6.6' is provided at a position facing the upper and lower perforations P of the film F,
As the film moves in the direction of the arrow, the switch is turned on every time it falls into a perforation and generates a film feed signal.

FIG. 3 shows the rear side of the back cover 2, and a data display section 8 displays data characters 9 indicating the year, month, and day, and characters or symbols 10 indicating, for example, the day of the week, by well-known means such as light emitting diodes or liquid crystals. There is. The data imprinting device 3 has a built-in display element that displays the same characters or symbols as the data 9.10 above, and as is well known, data is imprinted from the back side of the film screen in conjunction with the shirt release. It is structured in several ways, but the details will be omitted.

FIG. 4 shows the circuit of the feed confirmation device, where S is a film feed detection switch formed by the ball contact pieces 6, 6' and the camera body, C is a capacitor, R1,)
1, 2. R, 3 is a resistor □, Tr is a transistor, 11
is the data display drive circuit, and E is a power supply. In this circuit, when the film is fed, when a pulse is generated by the continuous opening and closing of the switch S by the perforation, a rectangular wave signal is generated at point A by the above capacitor, resistor, and transistor, and this signal is used to drive the The signal is input to the circuit 11, and the film feeding display symbol 10 blinks.

FIG. 5 shows another embodiment, in which a data display section 8 on the back cover is provided with characters 9 for displaying the above-mentioned date, etc., and a symbol 12 for confirming feeding. Data to be loaded is displayed by display characters 9, and when film feeding is detected by the ball contact piece, the data display disappears and a feeding confirmation symbol 12 flashes.

In the figure, the pulse detector 13 outputs a signal B as a feeding confirmation mode when a continuous rectangular wave is input from point A in FIG. When the level remains high or low, a signal C is output as a data display mode.

14 is a ring counter, which outputs signal 1 when the input signal A changes from high level to low level, and turns off signal 1 when the next input changes from low level to high level [
Exit signal 2. Continue this operation one after another, and when you reach signal 6, you will return to Iha 1.

In the normal mode, the determination control circuit 15 receives input from the clock date circuit 16 and outputs a date display to the display 9.

However, when the signal B is input from the pulse detector 16, the mode becomes one feeding confirmation mode, the date display disappears and the feeding confirmation symbol 12 is displayed, and when the signal from the counter 14 is input, the signal ( The symbols at the positions corresponding to 1 to 6) flash, allowing you to confirm feeding. The symbols 12 may be blinked in sequence. Next, when the pulse detector outputs a signal C as a feeding end signal, the normal date display mode is returned to, and the display 9 displays the date in response to the input signal from the clock date circuit.

In the above configuration, when the film winding operation is started and the contact ball 6.61 detects the movement of the perforation, the feed confirmation mode signal B is output from the pulse detector 13, and the control circuit for determination 15 becomes the feeding confirmation mode, and the date display 9 is switched to the feeding display 12. Then, a count start signal is output from the pulse detector 16 to the counter 14, and a rectangular wave signal A is input to the counter to start counting, and as described above, the display 12 blinks sequentially and the film is actually fed. display that the When the film feeding stops, the rectangular wave signal 1 is not output, and the date display mode signal C is output from the pulse detector 13 to the discrimination control circuit 14, and the display changes from the feeding display 12 to the date display 9. At the same time, the pulse detector also outputs a count stop signal E to the counter, and the counter stops counting.

Since the present application has the above-mentioned configuration, the film feeding status can be reliably displayed with an extremely simple configuration that only requires adding a few detection members and circuit parts to a conventional camera having a data imprinting device on the back cover. Thus, a feeding confirmation device that can be used is obtained.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the film feeding camera, Fig. 2 is a perspective view showing the ball contact piece, Fig. 3 is a plan view showing the display part of the back cover, and Fig. 4 shows one embodiment. The circuit diagram shown in FIG. 5 is a circuit diagram showing another embodiment of the camera body.
・E back cover 3 inside・・Data imprinting device 4・I+@film pressure plate 61” ball contact piece 8・・Φ display section 9.
1[1@...Data display, 1111 drive circuit 12...
- Film feed display applicant: Canon Co., Ltd. agent, Gi Marushima -Δ゛iMO■・-4 11n乎? lV to r 133-

Claims (1)

[Claims] A camera having a data imprinting device on the back cover, characterized in that the film feeding state is electrically detected and the feeding status is displayed using display means of the data imprinting device. Feeding confirmation device.