JPS5953675B2 - flashlight device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flash light emitting device, such as a flash fixing device used in high-speed facsimiles, which requires a large amount of light emitting energy to be supplied at the same time.

Generally, fixing devices that utilize flash light are being adopted as fixing devices for facsimiles and the like because of their good start-up characteristics and safety.

The light emitting device used in this flash fixing device is one in which a capacitor is charged in advance and a flash is emitted at regular intervals or irregularly in response to a trigger signal.
Recently, as the recording speed of facsimile machines has become faster,
It has become necessary to increase the emitted energy of flash fixing devices.

As a method of increasing the luminous energy, it is difficult to increase the luminous energy per flash lamp, and if it is divided in time, it is not possible to obtain the desired fixing characteristics, so it is necessary to install multiple flash lamps. However, a method is generally used in which the flash lamps are caused to emit light at the same time and the emitted energy of each flash lamp is superimposed. One specific method is to increase the amount of photoelectric charge in a capacitor, connect a plurality of flash lamps in series, and simultaneously apply a light emission command. In this method, the increase in emitted energy due to the faster recording speed is compensated for by an increase in the amount of charge charged to the compatibility tower T, which means that the power supply becomes larger and the charging/discharging current also increases. Has its drawbacks. Furthermore, since flash lamps are connected in series, if the applied voltage per flash lamp is to be the same, the charging voltage of the capacitor must be increased according to the number of lamps connected in series.
Another drawback is that the withstand voltage of the capacitor must be increased. As a method to solve this drawback, there is a method of dividing the required amount of light emission energy into multiple systems, each having its own power supply and flash lamp, and applying a light emission command. This method has the following advantages: (1) Since the characteristics of the light emission trigger circuit and the characteristics of the flash lamp are different depending on the individual lamps, the light emission peaks do not necessarily coincide even if the light emission commands are applied at the same time.

(2) Since each power supply unit has different charging characteristics, non-emission is likely to occur due to incomplete charging. Therefore, since the emitted energy cannot be superimposed, there is a drawback that there is no meaning in dividing the emitted energy.

The present invention solves the above problems in the latter method,
The present invention relates to a flashlight emitting device that allows a plurality of flashlight lamps to emit light simultaneously and reliably, and that allows for easy increase and decrease of emitted light energy.

Hereinafter, the content of the present invention will be explained based on an example in the case where there are two flash lamps.

This device consists of two flash lamps 1 and 1, as shown in Fig.
2, a power supply section 3 corresponding to the flash lamp 1, and a charging control section 4
, a light emission trigger circuit 5, a power supply section 6 corresponding to the flash lamp 2, a charging control section 7, a light emission trigger circuit 8, a light emission command section 9, and a charge discharging section 10.

Of these, the flash lamp 1, power supply section 3, charge control section 4, and light emission trigger circuit 5 form a system 1, and the flash lamp 2, power supply section 6, charge control section 7, and light emission trigger circuit 8 form a system 2. do. These two systems are controlled by a light emission command section 9 and a charge discharge section 10. FIG. 2 shows an internal configuration diagram of the charging control section 4.

The charging control unit 4 supplies reference voltages to a voltage divider 11 that converts the terminal voltage of the charging capacitor inside the power supply unit 3 into a control voltage level, voltage comparators 12 and 14, and voltage comparators 12 and 14, respectively. Reference voltage generators 13 and 15, bistable multivibrators 16 and 17, and two AND
It is composed of circuits 18 and 19. Further, the charging control section 7 has the same configuration as the charging control section 4, and the power supply section 6 is connected instead of the power supply section 3. FIG. 3 shows the internal configuration of the light emission command section 9.

The light emission command unit 9 includes three AND circuits 20, 21, 22,
It is composed of a delay circuit 23. Figure 4 shows the charge discharge section 1.
The internal configuration of 0 is shown.

The charge discharging unit 10 includes voltage comparators 24 and 27, reference voltage generating units 25 and 28 that supply reference voltages to the voltage comparators 24 and 27, respectively, and a charging command time detection circuit that detects the length of the charging command time. 26, 29 and NOR circuits 30, 31
．． 0R circuit 34 and bistable multivibrator 32,3
3, and reset switches 35 and 36. The bistable multivibrators 32 and 33 are set when the systems 1 and 2 are in normal operation. Among these, the voltage comparator 24, the reference voltage generation section 25, the charging command time detection circuit 26, the NOR circuit 31. Bistable multivibrator 32 and reset switch 35 are in charge of system 1, voltage comparator 27, reference voltage generator 28, charge command time detection circuit 29, NOR circuit 31, bistable multivibrator 33
, the reset switch 36 is in charge of the system 2. Next, the operation of the present invention will be explained based on FIGS. 1 to 4, divided into charge control operation, light emission command operation, charge discharge operation, and light emission trigger operation.

First, the charging control operation will be explained using system 1.

In Figure 2, the voltage divider 11 is the charging capacitor 3C of the power supply section 3.
This converts the terminal voltage b (several hundred volts or more) into a low voltage system compatible with the control system. The voltage comparator 12 compares and detects the charging voltage of the charging capacitor 3C, and receives a voltage proportional to the set charging voltage from the reference voltage generator 13, so that the output signal level of the voltage divider 11 is lower than the set charging voltage. It has a function that sets the output when the charging voltage is exceeded, and resets the output when the set charging voltage is exceeded. On the other hand, the voltage comparator 14 determines the timing of repeated charging to the charging capacitor 3C, and is supplied with a voltage proportional to the repeated charging start voltage from the reference voltage generation section 15, so that the output signal level of the voltage divider 11 changes to the timing when the charging capacitor 3C is repeatedly charged. The output is set when the voltage is below the start voltage, and the output is reset when the voltage exceeds the start voltage.The start voltage for the repeat charge is generally set to a value sufficiently lower than the set charge voltage. In FIG. 1, when a charging start command a is applied (set) from the outside, it is first input to the charging command section 4.

In the initial state (such as when the power is turned on), there is no charging charge in the charging capacitor 3C in the power supply section 3, and the output of the voltage divider 11 is repeatedly lower than the charging voltage and the voltage comparators 12 and 14
are set together. As a result, the bistable multivibrator 17 is set and the output of the AND circuit 18 is set.

Therefore, during normal operation (when no operational abnormality is detected), the output of the AND circuit 19 is set, the charging command signal C is applied to the power supply section 3, the switch 3b is closed, and the DC power supply 3 is turned off.
The charging operation to the charging capacitor 3C starts from a. A switch 3e in the power supply unit 3 is used to discharge the charge in the charging capacitor 3C via a discharge resistor 3d when an abnormal operation occurs, and is normally in an open state. When the terminal voltage b of the charging capacitor 3C increases and the output m of the voltage divider 11 reaches the set charging voltage, a signal is output from the voltage comparator 12 and the bistable multivibrator 16 is set. As a result, the charging control section 4 outputs a charging completion signal f. At the same time, the output of the voltage comparator 12 is output from the AND circuit 18.
, 19, the charging command signal C is lowered, and the charging operation of the power supply unit 3 is stopped. The voltage comparator 12 has hysteresis operation characteristics, and when the terminal voltage b of the charging capacitor 3C decreases, the output level of the voltage comparator 12 is reversed and A
The charging command signal C is applied to the power supply section 3 through the ND circuits 18 and 19, and the photoelectric operation is performed again. While repeating such operations, the charging control unit 4 charges the charging capacitor 3C.
Keep the terminal voltage constant. In other words, it moves to keep the amount of charge constant. On the other hand, when a charging stop command signal k is externally applied from the light emitting command section 9 to the charging control section 4 in accordance with the light emitting command 1, the bistable multivibrator 17 is reset and charging is performed via the AND circuits 18 and 19. The command signal C is lowered to stop the charging operation of the power supply unit 3.

After that, a light emission trigger signal is applied to the flash lamp 1 to emit a flash, and when the charging capacitor terminal voltage b decreases and becomes lower than the reference voltage from the reference voltage generator 15, that is, the charging start voltage, the voltage comparator 14 is activated. Then, set the bistable multivibrator 17 and reset the bistable multivibrator 16. The output of the bistable multivibrator 17 is set and applied to the power supply section 3 as a charge command signal C via AND circuits 18 and 19, and the recharging operation is started. Note that the repeated operation continues until the charging start command a is reset. Further, the system 2 consisting of the flash lamp 2, the power supply section 6, and the charging control section 7 also performs the same operation as Dokzan.

In this way, system 1 and system 2 each independently perform charging control in parallel. Next, the light emission command operation will be explained using system 1.

Note that system 2 operates in the same way. First, as shown in FIG.
is input. Charge completion signals f and g are AND circuit 2
0 to the AND circuit 21. On the other hand, the light emission command signal 1 from the outside is applied to the other end of the AND circuit 21, and the light emission command signal is applied to the output of the AND circuit 21 only when the charging operations of both systems 1 and 2 are completed. , are sent to the AND circuit 22. The other one of the AND circuit 22
An abnormal operation signal h is applied to the terminal, and when the abnormal operation signal h is set, that is, during normal operation, A
A signal corresponding to the light emission command signal 1 is obtained from the output of the ND circuit 22, and as a charge stop command k, the bistable multivibrator 17 in the charge control section 4 is reset to prepare for the light emission operation. Further, the output of the AND circuit 22 is delayed by a delay circuit 23 for a certain period of time, and then passes through a light emission trigger circuit 5 and is applied to the flash lamp 1 as a trigger signal. Here, the delay circuit 23 has the role of separating the charging operation and the light emitting operation of this device and preventing light emission during charging. In this way, the light emission trigger signal is not applied until the charging operations of both system 1 and system 2 are completed. Next, the charge discharging operation will be explained using system 1.

Note that system 2 also operates in the same manner. Charge discharging operation occurs when the charging capacitor is overvoltage charged or when the terminal voltage of the charging capacitor does not rise during charging operation and an excessive charging time is required.
The charge discharging unit 10 detects an operational abnormality for each system, and based on the results, the charge discharging unit 10 has a function of stopping the charging operation, discharging the charged charge, and blocking the application of the light emission trigger signal. A voltage regulator output signal trigger signal m, a charging command signal C, a voltage divider output signal n of system 2, and a charging command signal e are input. The voltage divider output signals m and n are input to voltage comparators 24 and 27, respectively, and reference voltage generators 25 and 2
It is compared with the reference voltage from 8. These reference voltages are set in advance to voltages corresponding to the absolute maximum ratings of the charging capacitor. Voltage divider output m (system 1) and n
(system 2) exceeds the reference voltage, voltage comparators 24, 2
A detection signal is output from 7. On the other hand, when the charging command signal C is set, this signal is transmitted to the charging command signal detection circuit 26.
After being integrated by an integrating circuit consisting of a resistor 26a and a capacitor 26C, the voltage is compared with a reference voltage 26d.

Then, the output of the integrating circuit increases, and after a certain period of time, the reference voltage 2
6d, that is, when the charging command time exceeds a specified value, the voltage comparator 26e is set. Such a phenomenon occurs when an abnormality occurs in the power supply unit 3. Here, the diode 26b has a function of rapidly discharging the charge of the capacitor 26C when the charging command signal C is set so that the charging command time detection is repeated.
Also, regarding the charging command signal e (system 2), the voltage comparator 2
7. Perform the same operation in the charging command time detection circuit 29.
The outputs of voltage comparator 24 and charge command time detection circuit 26 are combined by NOR circuit 30 to set bistable multivibrator 32.

That is, when an abnormal operation occurs in the system 1, the bistable multivibrator 32 is set. Similarly, when an abnormal operation occurs in system 2, bistable multipipulator 33 is set. The outputs of the bistable multipipulators 32 and 33 pass through the 0R circuit 34 and are applied to the light emission command unit 9 as an abnormal operation signal R, and the application of the light emission trigger signal 1 is blocked via the AND circuit 22. At the same time, it is applied to the power supply section 3,
The switch 3e is operated to discharge the charge through the resistor 3d connected in parallel to the charging capacitor 3C. (A similar operation is performed in the power supply unit 6 for system 2.) In this way, if an operational abnormality occurs in at least one of system 1 and system 2, all charging and light emitting operations of this device will stop. . In addition, bistable multivibrator 3
2 and 33 are reset using reset switches 35 and 36 after removing the cause of the abnormal operation. Next, a light emission trigger operation for matching the light emission peaks of flash lamps 1 and 2 will be explained.

FIG. 5 shows a configuration in which a thyristor is used as a semiconductor switch as an embodiment of the present invention. In FIG. 5, the light emission trigger circuit 5 is composed of a thyristor Thl, a capacitor C1, a step-up transformer T1, and a delay circuit 36a, and the light-emission trigger circuit 8 is composed of a thyristor Th2, a capacitor C2, a step-up transformer T2, and a delay circuit 36b. , a DC power supply 35 supplies power to the light emission trigger circuits 5 and 8. Further, the light emission trigger circuit 5 is in charge of the system 1,
The light emission trigger circuit 8 is in charge of the system 2 and triggers each of the flash lamps 1 and 2. The operation of the light emission trigger circuits 5 and 8 will be explained using the timing charts shown in FIGS. 5 and 6.

DC power supply 35 constantly charges capacitors C1 and C2 to a constant voltage.

When the light emission trigger signal 1 is applied from the light emission command section 9 in this state, the delay circuits 36a and 36b delay the signal by time t1 and T2, respectively, and the signals r and S are applied to the thyristors Thl and Th2. The thyristor Thl is turned on by the signal r, and the charge in the capacitor C1 is discharged through the primary side of the step-up transformer T1. As a result, a trigger pulse p is generated on the secondary side of the step-up transformer T1.
The discharge of the charge in the capacitor C1 is completed, and the thyristor Th
When the current in l becomes less than the holding current, thyristor Thl is turned off and capacitor C is charged until the next trigger pulse is applied. Similarly, thyristor Th2
is turned on by the signal S and generates a trigger pulse 8 on the secondary side of the step-up transformer T2. trigger pulse p and q
is applied to flash lamps 1 and 2, and the emission trigger signal 1
Then, a flash is emitted with a delay of T2 and t4, respectively. Here, the delay times t1 and T in the delay circuits 36a and 36b are
2, it is possible to set T2=T4 and match the emission peaks. Also, if you know in advance which system among multiple flash lamps has the shortest delay time from the light emission trigger signal of the light emission peak,
Alternatively, if a specific system can be set to a small value, the light emission peaks can be made to match even if the delay circuit of the light emission trigger circuit of that system is omitted. That is, in the embodiment, if the magnitude of (T2-t1) or (T4-T3) is known in advance, the delay time corresponding to the smaller one [t1 for (T2-t1), ( For T4-T3), set T3] to zero (t1
When setting T3 to zero, the delay circuit 36a can be omitted, and when setting T3 to zero, the delay circuit 36b can be omitted). The above is 2
Although we have explained the case where the system has three systems, the flash lamp, power supply section, charging control section, and light emission trigger circuit of system 3 are added, and the charging completion signal from system 3 is sent to the light emission command section 9. It is sufficient to input the light emission trigger signal to the AND circuit 20 and apply the light emission trigger signal to the system 3.

Furthermore, it is only necessary to add an operation abnormality detection function for the system 3 to the charge discharge section 10. In this way, according to the present invention, the luminous energy can be increased by adding the necessary systems and with a slight modification.

The present invention has the following effects.

(1) The light emission trigger signal is applied to each flash lamp after detecting the charging completion operation of each power supply unit, so if charging is not completed (
It is possible to prevent non-emission of light due to charging energy being less than a specified value.

(2) By providing a delay circuit in the light emission trigger circuit, there is no time lag between the light emission trigger signal and the trigger pulse, and the light emission peaks of a plurality of flash lamps can be made to coincide. As a result, it is possible to supply the necessary light emission energy without running out, regardless of the characteristics of the light emission trigger circuit or the flash lamp. (3) When at least one system malfunctions, it is safe because the charges in all power supply units are discharged and the operation is stopped.

(4) By providing a power supply section for each flash lamp, the capacity per power supply section can be reduced, and miniaturization is possible.

(5) Emission energy can be easily increased or decreased by increasing or decreasing the power supply section.

(6) By providing a power supply section for each flash lamp and increasing the light emission energy by increasing the number of power supply sections, it is not necessary to increase the charging voltage as the light emission energy increases.

[Brief explanation of the drawing]

Figure 1 is an overall configuration diagram of the present invention, Figure 2 is a configuration diagram of a charging control section, Figure 3 is a configuration diagram of a light emission command section, Figure 4 is a configuration diagram of a charge discharging section, and Figure 5 is a diagram of a light emission trigger. The circuit diagram of the circuit, FIG. 6, shows a timing chart of the light emission trigger circuit. 1, 2... Flash lamp, 3, 6... Power supply section, 4, 7... Charging control section, 5, 8...
...Light emission trigger circuit, 9...Light emission command section, 10
...Charge discharge section, 11...Voltage divider, 1
2, 14, 24, 27... Voltage comparator, 13,
15, 25, 28...Reference voltage generation section, 23.
...delay circuit, 19,22...AND circuit, 26,29...charging time detection circuit, 30,
31, 34...0R circuit, 35...DC power supply, 36a, 36b...delay circuit.

Claims (1)

[Scope of Claims] 1. A plurality of flash lamps, a power supply unit, a charging control unit, a light emission trigger circuit provided corresponding to each lamp, a charging command unit that gives a charging command to each charging control unit, and each A light emission command unit receives a charge completion signal from the charge control unit, detects the completion of charging of all power supply units, and issues a light emission command, and controls charging of all flash lamps when at least one system malfunctions. A flashlight emitting device that collectively controls a plurality of flashlight lamps, which is comprised of a charge discharging section that stops operation and discharges a charged charge. 2. In claim 1, each light emission trigger circuit includes a capacitor, a step-up transformer, a semiconductor switch, and a delay circuit that delays the light emission command signal and provides a signal to the semiconductor switch after a certain period of time, A flashlight emitting device that matches the emission peaks of multiple flashlight lamps by changing the delay time of a trigger circuit.