JPH0459193A - Laser beam machine - Google Patents

Abstract

PURPOSE:To detect working defects based on some abnormal laser beam output and to prevent a large quantity of defectives from production by comparing each peak value of laser beam output with a preset prescribed value and controlling the output and suspension of the laser beam output in accordance with this comparison result. CONSTITUTION:When the laser beam machining is commenced, the maximum of the laser beam output 104 amplified by a power amplifying part 5 in time of laser beam machining is held at a peak holding part 6 interlocking with a Q switch pulse 101 from a control section l and outputted by a control signal 107 from the control section 1 as a peak hold output 106 from the peak hold part 6 to the comparison part 8. The comparison part 8 decides whether the peak hold output 106 of the laser beam power lies between the upper limit 109 and the lower limit 110 of the reference voltage from the reference voltage generating part 7, and when it does not lie between the upper limit 109 and the l lower limit 110, an alarm signal 111 is outputted to the control section 1. When the alarm signal 111 is inputted, the output of the Q switch pulse 101 is suspended as an abnormal laser beam output to stop laser beam machining at the control section 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a laser processing apparatus, and more particularly to a laser processing apparatus using a Q-switched laser.

Conventional Art Conventionally, this type of laser processing apparatus is comprised of a laser output monitor section that monitors the laser output, an amplification section that amplifies the output of the laser output monitor section, and a control section that controls the Q-switch pulse. There is.

When performing laser processing with this laser processing device, a specified Q-switch pulse is output from the control unit immediately before laser processing, and the laser output at that Q-switch frequency is detected by the laser output monitor unit and amplified by the amplifier unit. This is then displayed on the laser average output display section, and without looking at this displayed value, the input power or attenuator is adjusted so that the laser output becomes a predetermined value.

With such conventional laser processing equipment, the laser output is set immediately before laser processing, and the laser output cannot be checked during laser processing. When the laser output is checked for a long time, such as when performing unmanned operation in combination, the laser output may change until a visual inspection reveals a machining defect, or there may be an error with respect to the target value as in the case of laser trimming. If the output did not change, it was not possible to detect processing defects due to abnormal laser output.

Furthermore, processing defects due to slight abnormalities in laser output cannot be detected until they are found to be defective in a comprehensive inspection after the next process, resulting in the production of a large number of defective products.

Purpose of the Invention The present invention has been made to eliminate the drawbacks of the conventional products as described above, and is capable of detecting processing defects due to slight abnormalities in laser output, thereby preventing the production of a large number of defective products. The purpose is to provide laser processing equipment that can

Structure of the Invention A laser processing apparatus according to the present invention includes a detection means for detecting a laser output of a Q-switch laser, and a maximum value of the laser output detected by the detection means is synchronized with a Q-switch pulse to the Q-switch laser. a peak hold means for holding the peak value, a comparison means for comparing the maximum value held by the peak hold means and a predetermined value set in advance during processing using the laser output of the Q-switched laser, and a comparison result of the comparison means. It is characterized by comprising a control means for controlling the output and stop of the laser output from the Q-switched laser according to the above.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention. In the figure, a control unit 1 controls a laser beam 102 that is irradiated onto a workpiece 3 by controlling a Q-swivel laser 2 using a Q-switch pulse 101.

The laser output monitor section 4 monitors the laser output emitted from the Q-switched laser 2, and the laser output 103 detected as a voltage by the laser output monitor section 4 is amplified by the output amplification section 5 and sent to the peak hold section 6. is input.

The peak hold section 6 holds the maximum value (peak value) of the laser output 104 amplified by the output amplification section 5 in synchronization with the Q-switch pulse 101 from the control section 1, and applies it to the control signal 107 from the control section 1. Peak hold outputs 105 and 106 are output to the control section 1 or the comparison section 8 accordingly.

The control section 1 determines the upper and lower limits of the reference voltage from external input data 100 and the peak hold output 105 from the peak hold section 6, and then controls the reference voltage generation section 7 with a control signal 108 to generate the reference voltage. The unit 7 outputs the upper limit 109 of the reference voltage and the lower limit 110 of the reference voltage to the comparator 8.

The comparator 8 outputs the peak hold output 106 from the peak hold unit 6 and the upper limit 1 of the reference voltage from the reference voltage generator 7.
09 and the lower limit 110 of the reference voltage, and when it is detected that the peak hold output 106 is not between the upper limit 109 of the reference voltage and the lower limit 110 of the reference voltage, an alarm signal 111 is output to the control section 1.

FIG. 2 is a time chart showing the operation of one embodiment of the present invention. The operation of an embodiment of the present invention will be explained using FIG. 1 and FIG. 2.

First, when setting the laser output before laser processing, the peak hold unit 6 sets the maximum value of the laser output 104 amplified by the output amplification unit 5 (the value of the reference peak a in FIG. 2) to the Q-switch pulse from the control unit 1. 101 and outputs this peak hold output 105 to the control section 1.

The control unit 1 determines the upper and lower limits of the reference voltage from the permissible range of laser output given as input data 100 and the peak hold output 105 (value of reference peak a) from the peak hold unit 6, and outputs the control signal 10g. controls the reference voltage generation section 7 to set the upper limit 1 of the reference voltage to the comparison section 8.
09 and the lower limit 110 of the reference voltage are output.

Next, when laser processing is started, the maximum value (second
The values of each peak b-d in the figure) are held in the peak hold section 6 in synchronization with the Q switch pulse 101 from the control section 1, and are transferred from the peak hold section 6 to the comparison section 8 by the control signal 107 from the control section 1. It is output as a peak hold output 106.

In this case, the peak hold output 106 from the peak hold section 6 is cleared at the rising edge of the Q switch pulse 101 from the control section 1.

The comparator 8 determines whether the peak hold output 106 corresponding to each peak b-d of the laser output is between the upper limit 109 of the reference voltage from the reference voltage generator 7 and the lower limit 110 of the reference voltage, and determines whether the laser output If the peak hold output 106 corresponding to the peak C of is not between the upper limit 109 of the reference voltage and the lower limit 110 of the reference voltage, the alarm signal 1
11 is output to the control section 1.

When the control unit 1 receives the alarm signal 111 from the comparison unit 8, it outputs a Q-switch pulse 10 as a laser output abnormality.
Stop the output of step 1 and stop laser processing.

In addition, since the response of laser output detection is generally quite slow compared to the Q switch frequency, the laser output 103 output from the laser output monitor section 3 is the same value as the laser output used for actual processing. However, in one embodiment of the present invention, sampling of the reference value is performed under the same conditions as sampling during laser processing. Therefore, there is no problem when the comparing section 8 performs a comparison judgment.

In this way, the reference peak value of the laser output is sampled by the peak hold unit 6 in synchronization with the Q switch pulse 101 from the control unit 1 when setting the laser output before laser processing, and the reference peak value of the laser output is sampled in synchronization with the Q switch pulse 101 during laser processing. By comparing each peak value of the laser output sampled with the reference peak value in the comparing section 8, it is possible to check the laser output used for processing in real time during laser processing. It is possible to detect machining defects due to slight abnormalities in laser output that do not appear as visual inspection or trimming errors.

In addition, it is possible to prevent a large number of defective products from being produced due to slight abnormalities in laser output, such as when processing a large number of workpieces 3 at a time or when operating unmanned in combination with an automatic machine. I can do it.

In addition, in one embodiment of the present invention, when setting the laser output, the control unit 1
The reference peak value sampled in synchronization with the Q-switch pulse 101 from the control unit 1 is compared with each peak value of the laser output during laser processing. The reference peak value and each peak value of the laser output during laser processing may be compared, but the invention is not limited to this.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, each peak value of the laser output sampled in synchronization with the Q-switch pulse during laser processing is compared with a predetermined value set in advance, and according to the comparison result, By controlling the output and stop of the laser output, it is possible to detect processing defects due to slight abnormalities in the laser output, and it is possible to prevent the production of a large number of defective products.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a time chart showing the operation of the embodiment of the invention. Explanation of symbols of main parts 1... Control section 2... Q switch laser 4... Laser output monitor section 6... Peak hold section 7... ... Reference voltage generation section 8 ... Comparison section

Claims (1)

[Claims] (1) detection means for detecting the laser output of the Q-switch laser; and peak-hold means for holding the maximum value of the laser output detected by the detection means in synchronization with the Q-switch pulse to the Q-switch laser; a comparison means for comparing the maximum value held by the peak hold means and a predetermined value set in advance during processing by the laser output of the Q-switch laser; 1. A laser processing device comprising: control means for controlling output and stop of laser output.