JP3088057B2 - Flash lamp trigger circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flash lamp trigger circuit for generating a trigger voltage for lighting a flash lamp for exciting a solid-state laser.

[0002]

2. Description of the Related Art Generally, in a laser device using a solid-state laser such as a YAG laser, a flash lamp is used as an exciting means for exciting the solid-state laser.

FIG. 3 shows a conventional example of a flash lamp trigger circuit for generating a trigger voltage for lighting a flash lamp.

In FIG. 3 , a simmer circuit 5 is formed by connecting a DC power supply 2, a resistor 3 and a diode 4 in series to a cathode 1k and an anode 1a of the flash lamp 1, and the simmer circuit 5 once lights up. The discharged flash lamp 1 is pre-discharged.
A high-voltage pulse circuit 6 applies a trigger pulse between the cathode 1k of the flash lamp 1 and the trigger electrode 1t. This high voltage pulse circuit 6 has a DC power supply 8, a resistor 9 and a capacitor 10 connected in series to a primary coil of a trigger transformer 7, and a thyristor 11 connected in parallel to the DC power supply 8 and the resistor 9. A trigger capacitor 12 is connected between the secondary coil of the trigger transformer 7 and the trigger electrode 1t.

According to the conventional example shown in FIG. 3 , when the flash lamp 1 is turned on, the thyristor 11 of the high-voltage pulse circuit 6 is turned on and off, and for example, the voltage is reduced via the trigger transformer 7 and the trigger capacitor 12. About 20k
V, a trigger pulse having a pulse length of about 20 μs is applied to the cathode 1 k and the trigger electrode 1 t of the flash lamp 1, and at the same time, a lighting voltage of about 1000 V is applied to the flash lamp 1 by the simmer circuit 5. At this time, it is confirmed by measuring the current of the simmer circuit 5 whether or not the flash lamp 1 has been turned on. If the current has not been detected, it is determined that the flash lamp 1 has not been turned on. The trigger pulse is continuously generated every time.

After the flash lamp 1 is turned on, a current lower than the threshold current for exciting the solid-state laser is applied to the flash lamp 1 by the simmer circuit 5, so that the flash lamp 1 is in a preliminary discharge state. Will be retained. That is, when a trigger pulse is applied to the flash lamp 1, a lighting voltage of about 1000 V is applied to the flash lamp 1 by the simmer circuit 5, and about 1 V after lighting.
The voltage can be reduced to about 00V.

When exciting a solid-state laser,
A current higher than the threshold value flows between the cathode 1k and the anode 1a of the flash lamp 1 from a main excitation circuit for laser emission (not shown), and the flash lamp 1 emits light at a level at which a solid-state laser can be excited.

[0008]

However, in the above-mentioned prior art, the trigger pulse must be set to a high voltage of 20 kV in order to stably turn on the flash lamp 1, and this high voltage trigger pulse is generated. Then, a very high level of noise is generated, and there is a possibility that not only the solid-state laser device itself but also external peripheral devices may malfunction. Further, in order to generate a high voltage as high as 20 kV, the trigger transformer 7, the capacitor 10, and the like, which are components of the high-voltage pulse circuit 6, are disadvantageously large and expensive.

[0009]

In order to achieve the above object, a trigger circuit for a flash lamp according to the present invention comprises: a flash lamp for exciting a solid-state laser; a simmer circuit for pre-discharging the flash lamp; A dc voltage circuit for applying a trigger dc voltage to the anode and cathode of the flash lamp, wherein the simmer circuit applies a trigger dc voltage applied to the flash lamp from the dc voltage circuit to the simmer circuit has a diode for blocking is of a is, the DC voltage circuit before
The cassette is located outside the flash lamp
With an auxiliary electrode electrically connected to the
In addition, the capacitor that generates the DC voltage for trigger
-It is characterized in that it is formed so as to apply an AC voltage from an AC converter.

[0010]

In order to achieve the above object, a trigger circuit for a flash lamp according to the present invention comprises: a flash lamp for exciting a solid-state laser; a simmer circuit for pre-discharging the flash lamp; The flash lamp further comprises a DC voltage circuit for applying a trigger DC voltage to the anode and the cathode of the flash lamp.

[0011]

According to the present invention, the trigger DC voltage is applied to the anode and cathode of the flash lamp by the DC voltage circuit to turn on the flash lamp, so that the trigger DC voltage is greatly reduced. The noise level can also be very low.

[0012]

EXAMPLES Hereinafter, an embodiment of the present invention for FIGS.

FIG. 1 shows an embodiment of the present invention, and the same parts as those of the prior art are denoted by the same reference numerals. In this embodiment, the cathode 1k and the anode 1a of the flash lamp 1
A simmer circuit 24 is formed by connecting a DC power supply 21, a resistor 22, and a diode 23 in series, and the flash lamp 1 once lit by the simmer circuit 24 is preliminarily discharged. Further, between the cathode 1 k and the anode 1 a of the flash lamp 1, a DC voltage for triggering the flash lamp 1 (several kV: about 5 kV) is applied from the DC voltage circuit 25. Outside of this flash lamp 1,
A metal chamber covering the flash lamp 1
Is provided. This auxiliary electrode
1s is connected to the cathode 1k. Shimmer circuit 24
A current meter for measuring the current of the simmer circuit 24, and a feedback circuit 2 for turning off the DC voltage circuit 25 when the ammeter detects that the current flows to the simmer circuit 24.
6 are provided.

As the DC voltage circuit 25, various circuits as shown in FIG. 2 may be used. On the other hand, in FIG.
V DC voltage is once converted to AC and output, and the AC voltage is several kV
And output from the output terminals 30 and 30.

Next, the operation of this embodiment will be described.

First, when the flash lamp 1 is turned on, the DC voltage circuit 25 is turned on to apply a trigger DC voltage of several kV to the cathode 1 k and anode 1 a of the flash lamp 1, and at the same time, the simmer circuit 24 operates. A lighting voltage of about 300 to 400 V is applied to the flash lamp 1. At this time, whether or not the flash lamp 1 is turned on is confirmed by measuring the current of the simmer circuit 24 by the feedback circuit 26, and the DC voltage circuit 25 is turned on until the current is detected. When detected, the DC voltage circuit 25 is turned off.

In this embodiment, the flash lamp 1
Since the initial current flows by applying a DC voltage of several kV to the cathode 1k and the anode 1a in the high impedance state for triggering, even if the trigger operation is stopped thereafter, the simmer current is several hundred mA to several A. At this point, the preliminary discharge of the flash lamp 1 is continued.

After the flash lamp 1 is turned on in this way, a current lower than the threshold current for exciting the solid-state laser is applied to the flash lamp 1 by the simmer circuit 24, and the flash lamp 1 is turned on. It is kept in the preliminary discharge state. That is, when a DC voltage for trigger is applied to the flash lamp 1, a lighting voltage of about 300 to 400 V is applied to the flash lamp 1 by the simmer circuit 24, and after lighting, the voltage is reduced to a voltage of about 100V.

When exciting a solid-state laser,
A current higher than the threshold value flows between the cathode 1k and the anode 1a of the flash lamp 1 from a main excitation circuit for laser emission (not shown), and the flash lamp 1 emits light at a level at which a solid-state laser can be excited.

Therefore, according to the present invention, the DC voltage circuit 2
5, a trigger DC voltage is applied to the anode 1a and the cathode 1k of the flash lamp 1 to turn on the flash lamp 1. Therefore, a conventional high trigger voltage of 20 kV is used as a trigger voltage of several kV. DC voltage can be greatly reduced, and thus the noise level can be extremely low, and the leakage of noise to the outside can be reliably prevented. Can also be prevented. Further, the DC voltage circuit 25 outputs a DC voltage of several kV, and each component is smaller and the cost is lower than that of the conventional high voltage pulse circuit 6 which outputs a pulse voltage of 20 kV. . Furthermore, Shimmer circuit 2
4, the maximum output voltage may be 300 to 400 V, and each component is small in size and the cost is low as compared with the conventional simmer circuit 5 in which the maximum output voltage reaches 1000 V.

It should be noted that the present invention is not limited to the above-described embodiment, and can be modified as needed.

[0022]

As described above, since the flash lamp trigger circuit of the present invention is constructed and operates, the level of noise generated at the time of triggering the flash lamp to be turned on can be reduced, and the overall configuration can be reduced in size. And the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of a trigger circuit for a flash lamp according to the present invention.

FIG. 2 is a circuit diagram showing one embodiment of a DC voltage circuit.

FIG. 3 is a circuit diagram showing an example of a conventional flash lamp trigger circuit.

Claims (1)

(57) [Claims] 1. A flash lamp for exciting a solid-state laser, a simmer circuit for pre-discharging the flash lamp, and a DC voltage circuit for applying a trigger DC voltage to an anode and a cathode of the flash lamp. And the simmer circuit has a diode for preventing a DC voltage for trigger applied to the flash lamp from the DC voltage circuit from being applied to the simmer circuit,
The DC voltage circuit is arranged outside the flash lamp
Auxiliary which is electrically connected to the cathode
A trigger circuit for a flash lamp, characterized by having electrodes and being formed so as to apply an AC voltage from a DC-AC converter to a capacitor for generating a DC voltage for a trigger.