JPS59148298A - Lamp indicator of flash discharge light emitting unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lamp display device for a flash discharge light emitting device used in photography.

As is widely known, in this type of flash discharge light emitting device, the main discharge capacitor is charged, and when the charging voltage of this capacitor reaches a predetermined value, the ready lamp lights up to indicate that it is ready to emit light. It is supposed to be done. In many cases, the ready lamp continues to be lit as long as the charging voltage of the main discharge capacitor is a predetermined value or more.

On the other hand, since a flash discharge light emitting device is used when the subject is dark, it is preferable to have a pilot lamp that lights up at the same time as the electric switch is turned on. The light emitter requires at least this pilot lamp and the above-mentioned ready lamp.

However, providing such two lamp display means separately increases the complexity of the circuit configuration, and also increases the installation area and
This results in an increase in the number of circuit components.

The present invention was developed in view of the above-mentioned circumstances, and an object of the present invention is to configure a pilot lamp function and a ready lamp function to be achieved by one lamp display means.

Therefore, the present invention provides a flash discharge light emitting device in which the stored energy of a main discharge capacitor charged by a -y converter including an oscillation transistor is converted into light energy by a flash discharge tube. a switch means for stopping the oscillation of the converter by connecting the base of the oscillation transistor and the main discharge capacitor when the converter is charged to a charging voltage of A lamp display device comprising lamp display means whose display changes is proposed.

According to the present invention configured as described above, the lamp can be lit continuously from when the power switch is turned on until the charging voltage of the main discharge capacitor reaches a predetermined value.

That is, since the DC-DC converter continues to oscillate while the main discharge capacitor reaches a predetermined charge voltage, the lamp display means that responds to the voltage fluctuation signal lights the lamp continuously. .

Further, when the main discharge capacitor is charged to a predetermined value, the lamp repeatedly flashes to indicate that the device is ready to emit light. That is, when the charging pressure of the main discharge capacitor reaches a predetermined value, the oscillation of the DC-DC converter temporarily stops, and therefore the lamp that has been lit continuously turns off. However, as the oscillation of the DC-■ converter stops, the charge in the main discharge capacitor is discharged through the conductive switch means, so the charge voltage in the main discharge capacitor drops below a predetermined value, and the switch means shuts off. return to the state. This operation causes the DC-DC converter to start oscillating again, charging the main discharge capacitor to a predetermined charging voltage. When the DC-DC converter starts oscillating again, the lamp is turned on, and the lamp is turned off when the main discharge capacitor is charged to a predetermined value.

In this way, after the charging pressure of the main discharge capacitor reaches a predetermined value, the lamp blinks, and it can be clearly distinguished from the continuous lighting display that charging is in progress.

Next, examples of the present invention will be described.

FIG. 1C shows a flash discharge emitter circuit with a lamp display device according to the invention. In this figure, 1 is a battery power source, 2 is a power switch, 3 is an oscillation transformer, and 4 is an oscillation transistor. These transformer 3 and the four transistors form a known IJC-DC converter. 5 is a starting resistor of the converter, and 6 is a capacitor for stabilizing the operation of the converter.

7. Capacitors and diodes forming an 8-digit smoothing circuit,
Reference numeral 9 denotes a main discharge capacitor charged by the DC-DC converter, and IO is a discharge tube that emits flash light upon receiving the stain energy from the main discharge capacitor 9.

1] is a charging resistor, I2 is a trigger capacitor, J3 is a trigger transformer, and 1.4H) is a trigger switch, and each of these members forms a known trigger circuit that applies an excitation voltage to the discharge tube IO.

Reference numeral 15 indicates a constant voltage element, and reference numeral 16 indicates a holding resistor. These series circuits connect the base of the oscillation transistor 4 and the negative potential side circuit line of the main discharge capacitor 9 in a continuous manner. The constant voltage element J5 has a forward direction in which the base current of the oscillation transistor 4 flows. This series circuit forms a kind of switching means, and conducts to discharge a part of the charge of the main discharge capacitor 9 when the main discharge capacitor 9 is charged to a predetermined value.

A series circuit consisting of 17 protective resistors and 18 light emitting diodes forms a lamp display means connected in parallel with a part of the coil of the oscillation transformer 3. Note that the light emitting diodes 18 may be connected in the opposite direction as shown by the phantom lines.

The above-mentioned flash discharge emitter circuit has a power switch 2t[[
Then, the DC-DC converter immediately starts oscillating as in a known operation, so that the light emitting diode 1B lights up almost at the same time as the power switch 2 is turned on. That is, by repeating ON and OFF of the oscillation transistor 4,
The light emitting diode 18 is powered by the battery power source 1 and lights up. In this case, the light emitting diode 18 will be intermittently supplied with power, but it will be interrupted. Note that when the light emitting diode 18 is connected as shown in the diagram, the − of the oscillation transformer 3 is
The light is turned on by the back electromotive force generated in the next coil.

T) When the C-DC converter starts oscillating, the main discharge capacitor 9 and the trigger capacitor 12 are charged in a known manner.

When the main discharge capacitor 9 is charged to a predetermined charging voltage,
Since the constant voltage element 15 is in a conductive state, a part of the charge of the capacitor 9 is discharged through the path of the emitter base of the oscillation transistor 4, the protection resistor 16, and the constant voltage element 15.

As a result, the base current of the oscillation transistor 4 flowing due to the electrical energy stored in the oscillation transformer 3 is blocked, and the transistor 4 continues to be in the OFF state. That is, the oscillation of the DC-DC converter is stopped and the light emitting diode 18 is turned off.

The charging voltage of the main discharge capacitor 9 gradually drops from a predetermined value due to the above-mentioned discharge of the charge, and therefore, the constant voltage element 15 becomes non-conductive within a short time (for example, 0.5 seconds) after it becomes conductive. to return to.

When the constant voltage element 15 becomes non-conductive, the oscillation transistor 4
Since the current from the battery power source 1 is sent to
The DC converter starts oscillating again.

Therefore, the light emitting diode 18 lights up and the main discharge capacitor 9 is charged until it reaches a predetermined charging voltage.

When the charging voltage of the main discharge capacitor 9 reaches a predetermined value through this charging operation, the oscillation of the DC-y converter stops and the light emitting diode 18 turns off in the same manner as described above.

Thereafter, in the same way, a small amount of the main discharge capacitor 9 is charged and discharged, and D
Oscillation and stop of C-DC converter and light emitting diode 1
80 is repeatedly turned on and off, and the charging pressure of the main discharge capacitor 9 is maintained almost constant.

As mentioned above, the light emitting diode 18 is connected to the power switch 2
The lamp lights up continuously from when the main discharge capacitor 9 is turned on until the main discharge capacitor 9 reaches a predetermined charging pressure, and after the charging pressure of the main discharge capacitor 9 reaches a predetermined value, it blinks.

Therefore, if you close the trigger switch 14 after confirming that the light emitting diode 18 is blinking,
The discharge tube 10 emits light in a known manner.

FIG. 2 shows an embodiment in which the light emitting diode 18 is supplied with power by the transistor J9 which operates in response to a voltage fluctuation signal at the connection point P between the oscillation transistor 4 and the oscillation transformer 3. It is the same as the example shown in the figure.

Fig. 3 shows an embodiment in which the flash discharge emitter circuit shown in Fig. 1 is installed in a camera. -This is a transistor that stops the oscillation of the DC converter. Further, 23 is a CDS that detects the brightness of the field, 24 is a transistor that becomes conductive according to the resistance value of the CDS 23, and 5 is a light emitting diode.These components determine the brightness of the field. Forms a discrimination circuit. This discrimination circuit operates when the brightness level of the object field is below a predetermined value and turns on the light emitting diode 5 to indicate that flash light emission is necessary for photographing.

Further, this embodiment is provided with power switches 2α and 2b, where 2α is the power switch for the motor 2fJ and the discrimination circuit described above, and 2b is the power switch for the flash discharge emitter circuit.

In this embodiment, when the power switch 2α is first turned on, the light emitting diode 5 lights up in accordance with the brightness level of the object scene.

If the light emitting diode section does not light up, normal photography can be performed by releasing the shutter while the power switch 2b is open.
1 is opened and closed for a short time, and the photographed film is transported by the drive of the motor.

On the other hand, when the light emitting diode 5 is lit, the power switch 2b is turned on to prepare for flash photography.

When the power switch 2b is turned on, the DC-DC converter immediately starts oscillating, and when the main discharge capacitor 9 reaches a predetermined charging voltage as in the embodiment shown in FIG. Displays that the light is ready to emit light. Therefore, flash photography is performed by releasing the shutter under this condition. Immediately after the shutter release, the switch 21 is closed and the film is transported by the motor 20. However, during the short period when power is being supplied to the motor, the transistor 22 is conductive and the base and emitter of the oscillation transistor 4 are short-circuited. As a result, the oscillation of the DC-T)C converter stops.

Next, FIG. 4 shows an embodiment in which a PNP type transistor is used as the oscillation transistor 4. In this example, the first
Since it is necessary to reverse the polarity of the battery power supply 1 compared to the illustrated embodiment, the diode 8 and the constant voltage element 15 are connected in opposite directions. Note that the light emitting diodes 18 do not necessarily need to be connected in the opposite direction.

In addition, as in the embodiment shown in FIG.
Even if it is removed, there are many practical problems. This is true not only for the embodiment shown in FIG. 4 but also for each embodiment.

FIG. 5 shows an embodiment in which a series circuit of a protective resistor 17 and a light emitting diode 18 including a lamp display means is connected to the base of the oscillation transistor 4. While the DC-DC converter is oscillating, a high-frequency base current flows into the oscillation transistor 4, so even if the structure is configured as in this embodiment, lamp display is performed almost in the same manner as in the embodiment in FIG.

FIG. 6 shows an embodiment in which the power supply to the light emitting diode 18 is determined by the transistor 26 which operates by inputting the voltage fluctuation signal appearing at the base of the oscillation transistor 4 to the base.

In Figure 7, a tertiary coil is provided in the oscillation transformer 3, and the light emitting diode 1 is
This is an embodiment in which 8 is lit and also blinks.

FIG. 8 shows an embodiment in which a series circuit of a protective resistor 27 and a neon lamp 4 as lamp display means is connected in parallel to the secondary coil of the oscillation transformer 3.

As described above, the lamp display device according to the present invention lights up continuously while the main discharge capacitor is being charged to a predetermined charging voltage to indicate that the main discharge capacitor is in the charging state. After the charging pressure reaches a predetermined value, the flashing is repeated to indicate that the flash discharge device is ready to emit light, so the charging state of the flash discharge light emitter and the state that it is ready to emit light can be reliably confirmed by one lamp display means. can be understood.

Further, according to the present invention, one dump display device functions as a pilot lamp and a ready lamp, which not only simplifies the circuit configuration, but also allows the pilot lamp circuit and the ready lamp circuit to be integrated. Battery power consumption is reduced compared to separately provided conventional flash discharge emitters.

In addition, in the lamp display device of the present invention, when the capacity of the main discharge capacitor is large, the interval between lamp blinks becomes long.
For example, it is particularly effective when used in a flash discharge light emitting device with a small amount of light, which is equipped with a main discharge capacitor of about 10 μF to 150 μF.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIGS. 1 and 2 are circuit diagrams of a flash discharge light emitter showing an embodiment of lighting and blinking a light emitting diode in response to a voltage fluctuation signal appearing at the collector of an oscillation transistor, Figure 3 is a circuit diagram of a flash discharge light emitter built into a camera, Figure 4 is a circuit diagram similar to Figure 1 using a PNP type oscillation transistor, and Figures 5 and 6 are a circuit diagram of a flash discharge light emitting device built into a camera. FIG. 7 is a circuit diagram of a flash discharge light emitter showing an embodiment in which a light emitting diode is lit and blinked by a voltage fluctuation signal, and FIG. FIG. 8 is a circuit diagram of a flash discharge light emitter showing an embodiment in which a neon lamp is connected in parallel to the secondary coil of an oscillation transformer. 1...Battery power supply 2...Power switch 3...
・Oscillation transformer 4...Oscillation transistor 9・
...Main discharge capacitor 10...Discharge tube ]5.
16... Constant voltage element and protective resistor forming switch means 17.1.8... Protective resistor and light emitting diode forming lamp display means

Claims (1)

[Claims] In a flash discharge light emitting device configured such that the stored energy of a main discharge capacitor charged by a DC-DC converter including an oscillation transistor is converted into light energy by a flash discharge tube, the main discharge capacitor is charged at a predetermined charging voltage 1. A switch means that connects the base of the oscillation transistor and the main discharge capacitor when charged to stop the oscillation of the converter, and a lamp display that changes its display in response to a voltage fluctuation signal generated due to the oscillation operation of the oscillation transistor. A lamp display device comprising means.