JPS6027376Y2 - self timer circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a self-timer circuit, and more particularly, to a self-timer circuit that is capable of displaying a preview of shutter operation before generating a signal for operating the shutter.

Generally speaking, when photographing using a self-timer, it is easier for the person to be photographed if he or she can receive a notice of shutter operation immediately before the shutter is activated.

The invention disclosed in Japanese Patent Publication No. 47-47804 was made to solve such problems, and its gist is that it consists of a time constant circuit consisting of one transistor, a capacitor, a resistor, etc., and a low frequency oscillation circuit. , consisting of a pulse counting circuit and an electromagnet connected to a transistor switching circuit, the time constant circuit is activated by the release of a self-timer, and after a predetermined time has elapsed, the low frequency oscillation circuit is activated by the time constant circuit, and , the output pulses of the low frequency oscillation circuit are guided to the pulse counting circuit and counted, and when a predetermined number of pulses is reached, the transistor switching circuit is activated by the output of the pulse counting circuit and the shutter is actuated by the electromagnet. The release operation warning electric self-timer is characterized in that a lamp is made to blink by the operation of the low frequency oscillation circuit, and the shutter release operation timing is predicted by the blinking of the lamp.

According to this invention, the lamp can be turned on before the shutter is operated, and the intended purpose can be achieved even further.

Further, the invention related to Japanese Patent Application Laid-Open No. 51-7922 discloses a device that uses two LEDs and is capable of foretelling shutter operation during self-timer operation using one of the LEDs.

Further, the invention related to Japanese Patent Publication No. 47-30209 discloses a device that can predict shutter operation by blinking a lamp.

However, in this device, there is a possibility that the lamp continues to be lit even after the shutter operation is completed.

The purpose of this invention is to make one light emitting element light up continuously from when the self-timer is activated until a certain period of time before the shutter operation, to make it blink from a certain period of time before the shutter operation to the start of the shutter operation, and to make it possible to sip the sake mash during the shutter operation. The purpose of the present invention is to provide a self-timer circuit.

The self-timer circuit according to the present invention will be described in more detail below with reference to the drawings.

FIG. 1 is a circuit diagram showing an embodiment of a self-timer circuit according to the present invention.

FIG. 2 is a waveform diagram for explaining the operation of the above circuit.

In FIG. 1, the part surrounded by broken line 1 is the first time constant circuit, and the part surrounded by broken line 3 is the second time constant circuit, broken line 5.
The part surrounded by indicates an unstable multivibrator.

When the start switch 12 is opened, the terminal of the capacitor C1 included in the first time constant circuit is opened, and the capacitor C1
is charged with power supply voltage Vcc via resistor R1.

Figure 2a shows the change in voltage across capacitor C□.

Voltage E□ where the voltage of capacitor C1 is predetermined
When it reaches , the output of amplifier 2 reaches a low level.

As a result, the transistor 11 is turned off, the second time constant circuit 3 is activated, and at the same time the unstable multivibrator 5 is activated.

The voltage change of the capacitor C2 of the second time-fixing circuit is shown in FIG. 2, and the output waveform of the astable multivibrator is shown in FIG. 2d.

The output of the amplifier 2 maintains the bi-level until time t
) has maintained a buy level.

When the capacitor C2 is gradually charged via the charging resistor R2 and reaches the voltage E2 (see FIG. 2), the output of the amplifier 4 becomes low level (see FIG. 2C).

The Nantes gate 6 is a gate that forms a lighting signal.

The output of the Nant gate 6 is shown in FIG. 2e.

As shown in Figure 2e, the capacitor C of the first time constant circuit
Since the unstable multivibrator 5 is not operating until the voltage of 1 reaches El, the output of the Nandt gate 6 maintains a low level, and oscillates due to the vibration of the unstable multivibrator during the next period t2.

The point at which the output of the second time constant circuit becomes low level (t
t2=T), it becomes bilevel.

The LED 13 is supplied with current and lights up when the output of the Nant gate 6 becomes low level.

That is, the light is continuously lit for a period of t2, then blinks repeatedly for a period of t2, and then turned off.

The shutter operation is started when the voltage at point C in FIG. 1, that is, the output of the second time constant circuit becomes low level.

The effects of the circuit according to the present invention will be explained below in comparison with the circuit according to the invention using the counter described above.

According to the present invention, a second time constant circuit is provided, and the output thereof generates a shutter operation signal, and a gate circuit is provided, and the output of the second time constant circuit gates the output of the unstable multivibrator. , the flashing can be stopped at the same time as the shirt release.

Therefore, the person to be photographed can recognize that the shutter operation is approaching and that the shutter operation has started.

Since the circuit of the invention drives the lamp with a low-frequency oscillator, it is possible to predict the timing of the shutter release operation by the start of lighting of the lamp, but it is not possible to indicate the timing of the shutter release operation.

Next, in the circuit of the invention described above, flashing is performed to foretell the release time, but according to the present invention, the light emitting element can be turned on immediately after starting the self-timer.

This display allows the person to be photographed to confirm that the self-timer is operating reliably.

In this way, in the circuit according to the present invention, the first time constant circuit starts the astable multivibrator and the second time constant circuit, and the output of the second time constant circuit and the output of the astable multivibrator are added to the gate circuit. Since the light emitting elements are controlled by the gate output, the various displays described above can be reliably performed, and the self-timer operation and display can be rationally combined.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of a self-timer circuit according to the present invention, and FIG. 2 is a waveform diagram for explaining the operation of the circuit. 1...First time constant circuit, 2, 4...
Amplifier, 3...Second time constant circuit, 5...
・・Unstable multivibrator, 6, 7・・・・Nant gate, death・・Inverter, 10・・・・
・Resistance, 11...Transistor, 12...
...Start switch, 13...Light emitting diode (
LED), C... Capacitor included in the first time constant circuit, C2... Capacitor included in the second time constant circuit.

Claims (1)

[Scope of utility model registration request] A first time constant circuit 1, which is made up of a resistor R□, a capacitor C□, and an amplifier 2 that is inverted when the voltage of the capacitor C1 reaches a certain value, is started to operate when a self-timer is activated, and a resistor R2 and a capacitor C2. and an amplifier 4 that inverts and generates a shutter operation start signal when the voltage of the capacitor C2 reaches a certain value; and a semiconductor switch 11 that detects the reversal and starts charging the capacitor C2; an unstable multivibrator 5 activated by the reversal of the amplifier 2 of the first time constant circuit 1; and the second time constant circuit 3. a gate circuit 6 that gates the output of the unstable multivibrator upon the reversal of , and forms a lighting signal for a period until the reversal of the second time constant circuit 3;
and a light emitting element circuit 13 that is turned on by the output of the gate circuit 6.