JPH1084156A - Laser oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser oscillator by which the overshooting of an optical power is avoided and a stable laser output can be obtained. SOLUTION: An oscillator control unit 5 receives a laser output command signal 23 from an NC apparatus 3 and outputs a voltage waveform command signal 25 which is supplied to a power supply unit 9. The power supply unit 9 supplies a discharge power to an oscillation head 15 which outputs a laser beam LB. The outputted laser beam LB is detected by a laser beam detecting means 17 which supplies a detection signal to a comparator 19. On the other hand, a simulator unit 21 simulates the operation since the oscillation control unit 5 receives the laser output command signal 23 till the laser beam detector 17 outputs the detection signal V2 and supplies a simulation signal V1 to the comparator 19. The comparator 19 detects the deviation between the detection signal V2 of the laser beam detector 17 and the simulation signal V1 and the negative feedback of the deviation is performed by an adder 7 to correct the voltage waveform command signal 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser oscillator, and more particularly, to a laser oscillator that controls optical power by correcting a voltage waveform command signal.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional laser oscillator 101 using an optical waveform command.
No. 78 is disclosed. That is, the first signal processing unit 105 converts a command such as a frequency, a duty, and an amplitude issued from the NC device 103 into an optical waveform command signal 107 and transmits the signal to the second signal processing unit 111 via the adder 109. .

A second signal processing section 111 converts the optical waveform command signal 107 into a voltage waveform command signal 113,
15 The power supply unit 115 includes a DCPU 117
And the RFPU 119, and the DCPU 117
Then, a DC variable voltage is obtained from a commercial power supply to perform pulse modulation and the like.

[0004] Further, the RFPU 119 converts the DC voltage to R
The laser beam LB is emitted from the oscillation head 121 after conversion into F (high frequency alternating current) and high voltage. Oscillation head 121
The laser light LB emitted from the optical sensor 123 is detected by the optical sensor 123, and the optical output detection signal V ₂ is sent to the comparator 125. The optical output detection signal V ₂ has a delay T ₁ for converting the light signal waveform command to the voltage wave command, a delay T ₂ (see FIG. 5) due to the delay and the base discharge time from the voltage waveform command to discharge I have.

On the other hand, the optical waveform command signal 107 from the first signal processing unit 105 is delayed by the optical sensor 123 (several 100).
The laser output command signal V ₁ matched to the response characteristic of the optical sensor 123 is sent to the comparator 125 by the CR filter 127 having the same delay as ms).

[0006] The comparator 125 receives the input optical sensor 123.
Of the laser output command signal V ₁ from the CR filter 127 and the optical output detection signal V ₂ from the CR filter 127, and the adder 109 adds the deviation to the optical waveform command signal from the first signal processing unit 105. Then, the optical power is controlled by correcting this and sending it to the power supply unit 115 via the second signal processing unit 111.

Next, referring to FIG. 4, there is shown a laser oscillator 131 which does not use an optical waveform command. In addition,
The same parts as those of the laser oscillator 101 shown in FIG. 3 are denoted by the same reference numerals.

In the laser oscillator 129, the NC device 1
When a laser output command signal 131 such as frequency, duty, amplitude, etc. is sent to the oscillator control unit 133 from 03, the first signal processing unit 135 of the oscillator control unit 133 converts the laser output command signal 131 into an optical waveform command signal. Then, the signal is transmitted to the second signal processing unit 137, and the second signal processing unit 137 converts the optical waveform command signal into the voltage waveform command signal 113.
The voltage waveform command signal 113 is transmitted to the DCPU 117 of the power supply unit 115 via the adder 109.

The DCPU 117 obtains a DC variable voltage from a commercial power supply, performs pulse modulation and the like, further converts the DC voltage into RF (high-frequency alternating current) and high voltage with the RFPU 119, and emits a laser beam LB from the oscillation head 121. The optical sensor 123 detects the laser light LB and sends an optical output detection signal V ₂ to the comparator 125.

On the other hand, the voltage waveform command signal 113 from the oscillator control unit 133 is also sent to the simulator 139, and further sent to the comparator 125, which calculates the deviation from the optical output detection signal V ₂ from the optical sensor 123, and calculates the deviation. The light power is sent to the power supply unit 115, corrected as a negative signal and added to the voltage waveform command signal 113.

[0011]

However, referring to FIG. 5, in the laser oscillator 101 shown above, the signal V from the CR filter 127 to the comparator 125 is output.
₁ is the delay T _{1 of} the second signal processing unit 111 and the like (Equation 10)
For several milliseconds, the optical power may rise from a state where no optical power is output, and erroneous correction may be applied to cause a processing failure due to overshoot (addition of V ₁ -V ₂ ). Further, if the gain is reduced to suppress the overshoot, there is a problem that the stability of the optical power is reduced.

In the laser oscillator 129 shown next, the second signal processing unit 111 different from the laser oscillator 101 is not in a closed loop, and the voltage waveform command signal 113
Although the above-mentioned problem does not occur because the delay from the start to the base discharge can be simulated, when the simulator 139 is configured by an analog circuit, it must be manually adjusted to match the characteristics of each laser oscillator 129. It is troublesome because there are many adjustment points.

When the simulator 139 is digitally configured, the adjustment can be automated, but it takes time for processing, and the signal 141 of the optical sensor 123 is more than the output of the simulator 139, contrary to the above case. May rise up first and make erroneous corrections.

SUMMARY OF THE INVENTION An object of the present invention is to provide a laser oscillator capable of preventing an overshoot of optical power and obtaining a stable laser output by focusing attention on the above conventional technology. Is to do.

[0015]

According to another aspect of the present invention, there is provided a laser oscillator which receives a laser output command signal from an NC unit and converts it into a voltage waveform command signal. A power supply unit that receives a voltage waveform command signal from the oscillator control unit and supplies discharge power, and an oscillation head that emits a laser beam using the power from the power supply unit, and detects the laser beam from the oscillation head. A laser light detector, a simulator for simulating an operation from when the oscillator controller receives a laser output command signal to when the laser light detector emits a detection signal, a simulator signal from the simulator, and the laser light. A comparator that takes a deviation from a signal from the detector; and a negative feedback of the deviation from the comparator to the voltage waveform command signal to generate the voltage waveform command signal. A positive adder and is characterized in that it comprises an.

Therefore, the oscillator control section generates a voltage waveform command signal in response to the laser output command signal from the NC device, and the power supply section supplies discharge power to the oscillation head in response to the voltage waveform command signal to generate the laser beam. Output. The laser light detecting means detects the output laser light and issues a signal to the comparator. On the other hand, the simulator simulates the operation from the receipt of the laser output command signal by the oscillator control unit to the issuance of the detection signal by the laser light detector, and issues a simulation signal to the comparator. A comparator takes a deviation between the detection signal of the laser light detector and the simulation signal, and the adder negatively feeds back the deviation to the voltage waveform command signal to correct the voltage waveform command signal.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a laser oscillator 1 according to the present invention. In the laser oscillator 1, an oscillator control unit 5 is connected to the NC device 3. The oscillator control unit 5 is connected to a DCPU 11 of a power supply unit 9 via an adder 7, and also oscillates via an RFPU 13 of the power supply unit 9. The head 15 is connected.

An optical sensor 1 as a laser light detector for detecting the laser light LB emitted from the oscillation head 15
The optical sensor 17 is connected to a comparator 19.

On the other hand, the NC unit 3 has a DCPU 1
1, a simulator unit 21 that simulates the RFPU 13, the oscillation head 15, the optical sensor 17, and the like is connected. The simulator section 21 is connected to the comparator 19, and the comparator 19 is connected to the adder 7.

Accordingly, the oscillator control unit 5 converts the laser output command signal 23 such as the frequency, duty, and amplitude from the NC device 3 into a voltage waveform command signal 25. Further, the voltage waveform command signal 25 issued from the oscillator control unit 5 is transmitted to the power supply unit 9 via the adder 7.

On the other hand, the comparator 19 includes the DCPU 1
1, the simulation signal V ₁ from the simulator unit 21 for simulating all of the RFPU 13, the oscillation head 15, and the optical sensor 17, and the DCPU 11 and the RFPU
13, the oscillation head 15, the signal V ₂ from the light sensor 17 which has gone through all of the optical sensor 17 is inputted, by correcting the voltage waveform instruction signal 25 by adding the difference to the adder 7, the light Control power. The simulator section 21 outputs a simulation signal V ₁ based on the open-loop characteristic data (voltage waveform amplitude command corresponding to the amplitude command) that has been read in the oscillator control section 5 in advance.

[0023] Referring to FIG. 2, only the signal V ₂ is the time required until the discharge from the come laser output command signal 23 to the oscillator control unit 5 and the base discharge plus the time T _D from the optical sensor 17 oscillator control unit since rises later than the voltage waveform command signal 25 from 5, plus the time the base discharge to the discharge from the come simulated signal V ₁ in the same manner of the laser output command signal 23 from the simulator part 21 to the oscillator control unit 5 in the manner time only delay raises V ₁ and V ₂
To synchronize.

From the above results, the simulation signal V ₁ is delayed from the laser output command signal 23 by the time from when the laser output command signal 23 arrives at the oscillator control unit 5 to the discharge and the time T _{D obtained} by adding the base discharge. By outputting the signal, the signal can be synchronized with the signal from the optical sensor 17, so that stable control of the optical power can be performed. This allows
Processing defects due to overshoot of optical power can be avoided.

Further, by reading the open loop characteristic data into the oscillator control section 5, the adjustment can be automated.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes.

[0027]

As described above, in the laser oscillator according to the first aspect of the present invention, the oscillator control section generates a voltage waveform command signal in response to a laser output command signal from the NC device.
In response to the voltage waveform command signal, the power supply unit supplies discharge power to the oscillation head and outputs laser light. The outputted laser light is detected by the laser light detecting means and emits a signal to the comparator. On the other hand, the simulator unit simulates the operation from the receipt of the laser output command signal by the oscillator control unit to the emission of the detection signal by the laser light detector and emits a simulated signal to the comparator. Is input to the comparator in synchronization with the detection signal. For this reason, the comparator takes a deviation between the detection signal of the laser light detector and the simulation signal, and corrects the deviation by negatively feeding back the deviation to the voltage waveform command signal by the adder to correct the voltage waveform command signal. Corrections can be made. For this reason,
Processing defects due to overshoot can be avoided, and a stable output can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a laser oscillator according to the present invention.

FIG. 2 is a graph showing a relationship among a voltage waveform command, a simulator signal, and a signal from an optical sensor in FIG.

FIG. 3 is a block diagram showing a conventional laser oscillator using an optical waveform command.

FIG. 4 is a block diagram showing a conventional laser oscillator that does not use an optical waveform command.

FIG. 5 is a graph showing a relationship among signals in a conventional laser oscillator.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser oscillator 3 NC device 5 oscillator control unit 7 adder 9 power supply unit 15 oscillation head 17 optical sensor (laser light detector) 19 comparator 21 simulator unit 23 laser output command signal 25 voltage waveform command signal

Claims (1)

[Claims] An oscillator control unit that receives a laser output command signal from an NC device and converts the laser output command signal into a voltage waveform command signal; a power supply unit that receives a voltage waveform command signal from the oscillator control unit and supplies discharge power; A laser light detector that emits laser light with power from the power supply unit, a laser light detector that detects laser light from the oscillation head, and the laser light detection after the oscillator control unit receives a laser output command signal. A simulator for simulating the operation until the detector emits a detection signal, a comparator for obtaining a deviation between the simulator signal from the simulator and the signal from the laser light detector, and a deviation from the comparator for the voltage. A laser oscillator comprising: an adder that performs negative feedback on the waveform command signal to correct the voltage waveform command signal.