JPH0715066A - Pulse yag laser - Google Patents

Abstract

PURPOSE:To provide a pulse YAG laser being employed in various types of machining in which an optimal machining can be conducted continuously by allowing the setting of more than one optimal oscillation conditions even for the entirely different machining conditions. CONSTITUTION:A capacitor 2 is charged by a DC constant voltage power supply 1 constituting a power supply circuit and feeds energy to a lamp 5. The capacitor 2 is connected in parallel with a series circuit of a discharge impedance 15 and a switching circuit 4 for producing a predetermined charging voltage as well as a switching element, i.e., a transistor 3, for feeding a lamp 5 with charging energy from the capacitor 2. This circuitry provides a function for presetting more than one oscillation conditions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse YAG laser device which is excited by the light of a flash lamp or an arc lamp used in the industrial field.

[0002]

2. Description of the Related Art In recent years, solid-state YAG laser devices have been used as industrial machines in fields of semiconductors such as trimming and scribing, and marking, soldering, welding and cutting, and their fields of use are expanding year by year.

A conventional pulse YAG laser device will be described below. FIG. 2 is a diagram showing a structure of an optical resonance portion and a power supply portion of a pulse YAG laser using a conventional flash lamp. In FIG. 2, 1 is a constant voltage DC power supply for charging the capacitor, 2 is a capacitor for supplying energy to the lamp, 3 is a transistor as a switching element for limiting the lamp emission time by the capacitor 2, 12 is a transistor 3 The control circuit 5 that controls the control of the flash lamp 5 is a flash lamp and constitutes a power supply unit. Reference numeral 6 is a laser medium that absorbs the light emitted from the lamp 5, and reference numeral 7 is a cavity having a reflecting surface on its surface for allowing the light of the lamp to efficiently enter the laser medium, which constitutes an optical resonator.

The operation of the pulse YAG laser device constructed as described above will be described below. The energy of the capacitor 2 charged to a constant voltage by the constant voltage DC power supply 1 is supplied to the lamp 5 for a certain time by the transistor 3 which is a switching element. Due to the input energy to the lamp 5, the light emitted from the lamp for a certain period of time enters the laser medium 6 and is absorbed. The light that passes through without being absorbed is reflected by the reflecting surface of the cavity 7 and enters the laser medium 6 again. The energy of the absorbed light is oscillated by the optical resonator 10 surrounded by the partial transmission mirror 8 and the total reflection mirror 9, and a part of the energy becomes a laser beam 11 and is emitted to the outside.

At this time, since the energy supplied to the lamp 5 is the charging energy of the condenser 2, it is constant with respect to the time axis, and the energy emitted from the lamp can be arbitrarily changed in a short time or both ends of the condenser can be changed. It is difficult to change the light emission energy condition of the lamp immediately by changing the voltage of the lamp in a short time.

[0006]

However, in the above-mentioned conventional structure, when laser processing using a pulse YAG laser is performed, the energy of the laser cannot be arbitrarily changed with the passage of time, and the processing conditions are particularly extreme. When using under different oscillation conditions, it is necessary to set it according to the object to be processed. If this condition setting is neglected, there is a problem that the energy becomes excessive or the energy becomes insufficient.

The present invention solves the above-mentioned problems of the prior art. A pulse YAG laser can be used to set a plurality of laser processing conditions in accordance with an object to be processed, and optimum processing can be continuously performed. It is an object of the present invention to provide a pulsed YAG laser device.

[0008]

In order to achieve this object, the pulse YAG laser device of the present invention is charged by a DC power supply so that two or more oscillation conditions can be set in advance in the power supply section. The series circuit of the switching circuit and the discharge impedance for adjusting the capacitor charging voltage is connected in parallel with the capacitor that supplies energy to the lamp that emits light to the laser medium.

[0009]

With this configuration, when supplying the discharge energy of the capacitor to the lamp, when the switching circuit for adjusting the charge voltage is turned on in order to reduce the charge voltage of the capacitor, the energy supplied to the capacitor charge line is reduced. Since it can be changed, a plurality of laser processing conditions can be set according to the object to be processed, and optimum processing can be continuously performed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of a pulse YAG laser device according to an embodiment of the present invention. In FIG. 1, 1 is a constant voltage DC power supply for charging the capacitor, 2 is a capacitor for supplying energy to the lamp, 3 is a transistor which is a switching element for limiting the lamp emission time by the capacitor 2, 4
Is a switching circuit for adjusting the charging voltage of the capacitor 2, 13 is a charging voltage detecting circuit for detecting the charging voltage of the capacitor 2, 12 is a control circuit for controlling these operations, and 14 is a necessary condition for laser oscillation. Condition setting input function circuit for setting, 15 is a switching circuit 4
Is a discharge impedance connected to the capacitor 2. The discharge impedance 15 and the series circuit of the switching circuit 4 are connected to the capacitor 2. The structure of the resonance part is the same as the conventional one.

The operation of the pulse YAG laser device constructed as described above will be described below. The energy of the capacitor 2 charged to a constant voltage is supplied to the lamp 5 for a fixed time by the transistor 3 which is a switching element.
Is supplied to. Due to the energy input to the lamp 5, the lamp light emission for a certain period of time enters the laser medium 6. The energy of the absorbed light is oscillated by the optical resonator 10 surrounded by the partial transmission mirror 8 and the total reflection mirror 9, and a part of the energy becomes a laser beam 11 and is emitted to the outside.

At this time, the transistor 3 is turned on to supply energy to the lamp 5, but the supplied energy is the charging energy of the capacitor 2 and is constant with respect to the time axis. Therefore, to reduce the energy supplied to the lamp 5, the switching circuit 4 for adjusting the charging voltage is turned on to reduce the charging voltage of the capacitor 2 and reduce the energy to the lamp 5. On the contrary, in order to increase the energy, the switching circuit 4 is turned off to increase the charging voltage of the capacitor 2. This operation is performed by constantly changing the charging voltage of the capacitor 2 to the charging voltage detection circuit 13
The control circuit 12 controls the respective operations, and it is possible to respond from one lamp emission condition to the next emission condition in a short time. Therefore, by setting in advance the necessary conditions for laser oscillation (charge voltage, pulse width, pulse repetition rate, oscillation duration, transition time between oscillation conditions, etc.) The processing conditions can be continuously performed.

[0013]

As described above, according to the pulse YAG laser device of the present invention, two or more oscillation conditions can be set in advance, and when the charging voltage of the capacitor is lowered, the switching circuit for adjusting the charging voltage is turned on. By doing so, the energy supplied to the lamp can be continuously changed. Therefore, when performing laser processing using a pulsed laser, by setting the conditions that match the object to be processed in advance, energy can be saved especially for optimum processing that significantly changes not only the pulse width and the number of repetitions but also the charging voltage of the capacitor. It is possible to provide a pulse YAG laser device that enables optimum processing without causing an excessive amount or energy shortage.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a pulse YAG laser device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional pulse YAG laser device.

[Explanation of symbols]

 1 constant voltage DC power supply 2 capacitor 3 transistor 4 switching circuit 5 flash lamp 6 laser medium 7 cavity 8 partial transmission mirror 9 total reflection mirror 10 optical resonator 11 laser light 12 control circuit 13 charging voltage detection circuit 14 condition setting input function circuit 15 Discharge impedance

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Kobayashi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. A series circuit of a capacitor charging voltage adjusting discharge impedance and a switching circuit is connected in parallel with a capacitor for supplying energy to a lamp that is charged by a DC power source and emits light to a laser medium. A pulsed YAG laser device in which two or more conditions can be set in advance.