JPS63118730A - Action discriminating circuit for camera - Google Patents

Abstract

PURPOSE:To suppress shutter releasing even if a protection cover is opened while depressing a shutter releasing button by inhibiting the shutter releasing operation when the protection cover is opened during the depressing operation of the shutter button. CONSTITUTION:When switches 1, 2 are turned on, 'high' signals are outputted from inverters 3, 4. These outputs are inputted to an AND gate 9 and the output of the AND gate 9 is inputted to a sequence start signal generating circuit 6. Thereby, the 'high' signal is inputted to the circuit 6 only when both the switches 1, 2 are turned on. Namely, even if the release button is depressed when the protection cover is kept at the closed state, no signal is outputted from the circuit 6, so that the shutter can not be released and release lock is still held. Shutter release can be attained only by depressing the release button again.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a camera operation determination circuit, and more particularly to a camera operation determination circuit that determines the order of the opening operation of a protective cover for a photographic lens and the pressing operation of a shutter release button. This relates to a discrimination circuit.

[Prior Art] FIG. 2 shows the configuration of a conventional example. 1 is a switch that is linked to the shutter release button, 2 is a switch that is linked to the opening and closing of the protective cover, 3.4 is an inverter, 5 is an AND gate, and 6 is a sequence start signal that generates a sequence start signal based on the signal from AND gate 5. Signal generating circuits 7 and 8 are pull-up resistors for power supply Vcc.

Next, the operation will be explained. Switch 1.2 is inverter 3,
They are connected to the input sides of switches 1 and 2 respectively.
is turned on, inverter 3.4 outputs “High
” is output.

The output terminal of inverter 3.4 is input to AND gate 5, and the output terminal of AND gate 5 is connected to the input terminal of sequence start signal generation circuit 6. Both outputs of inverters 3 and 4 are set to ``H'' by AND gate 5.
Only when switches 1 and 2 are both on, the sequence start signal generating circuit 6 receives "'Hi".
gh” is input, a sequence start signal is issued,
There is a transition from lens barrel operation for focus adjustment to shutter release operation. This means that if the protective cover is closed, the shutter will not be released even if you press the shirt release button, which prevents wasted film and malfunctions. However, in this configuration, the input order of the switch linked to the shutter release button and the switch linked to the opening/closing of the protective cover is ignored. When opened, the shutter or release is exposed 0 If you compare this situation with normal shooting, you will find that even when you press the shutter release button, it does not release and the protective cover remains closed while the button is pressed. It is possible that the camera was released against the photographer's will, for example, when the user noticed this and opened the protective cover in a hurry, the camera was released at the same time. or will occur.

[Objective] It is an object of the present invention to eliminate the drawbacks of the conventional example described above, and to prevent the shutter release from being performed even if the protective cover is opened while the shutter release button is pressed.

[Embodiment] An embodiment of the present invention will be described below with reference to FIG. 1. Constituent elements similar to those of the conventional example are given the same reference numerals, and their explanation will be omitted. In the figure, 9 and 10 are AND gates, and 11 is an RS flip-flop (hereinafter referred to as RS-FF), which together constitute an operation determination circuit.

Next, when switches 1 and 2 are turned on, the inverters 3 and 4 output ``High''. This output is input to the AND gate 9, and the output of the AND gate 9 is the sequence start signal generation circuit 6. has been entered.

As a result, unless both switches 1 and 2 are turned on, the sequence start signal generation circuit 6 receives a "High" signal.
is not input. Here, the output of the inverter 3 and the input of the inverter 4 are input to the AND gate 10, and the output is connected to the input of the set of R-S-FFII.
The output Q of F is input to an AND gate 9. This ensures that switch 1 is on and switch 2 is off.
“Low” is stored in Q of S-FFII, and even if switch 2 is subsequently turned on, “Low” is stored in Q.
is output, the output of the AND gate 9 becomes “
Also, switch l is connected to the reset input of R-SF/Fil, and when switch l is turned off, it is reset and Q outputs “)Iigh”. When compared with the actual camera,
Even if the release button is pressed with the protective cover closed, no signal is output from the sequence start signal generation circuit 6, so the release does not occur, and even if the protective cover is opened in this state, the release lock remains applied. Therefore, the release is only possible by pressing the release button again.

[Effects of the Invention] As explained above, by using the operation determination circuit of the present invention, it is possible to accidentally press the release button with the protective cover closed and open the protective cover in a hurry while the button is still pressed. In this case, the sequence start signal is not output, so the film is not exposed, and it is possible to prevent shooting failures due to camera shake, etc.
The effect is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a conventional example. ■ = Switch that works in conjunction with the Nirreese button 2: Switch that works in conjunction with the protective cover 9.10: AND circuit 11: R-S flip-flop

Claims (1)

[Claims] A camera that has a protective cover that can be opened and closed on the front side of a photographic lens, and a switch that operates in conjunction with the opening and closing of the protective cover, so that when the protective cover is closed, the shutter release operation is prohibited by the activation of the switch. A circuit is provided to determine the order of the opening operation of the protective cover and the pressing operation of the shutter release button, and when the opening operation of the protective cover is performed during the pressing operation of the shutter button, the shutter release operation is prohibited. A camera operation determination circuit characterized by: