JPS60223180A - Laser output controller - Google Patents

Abstract

PURPOSE:To avoid any excessive output from a laser oscillator in case of starting operation by a method wherein the feedback of laser output is corrected by simulated feedback in case of starting operation. CONSTITUTION:Any delayed response speed of a laser beam detector 10 in case of starting operation of a laser oscillator is corrected by means of adding the laser output feedback by detecting laser beam 4A transmitted from an overall reflecting mirror 5A to the laser beam detector 10 to simulated feedback outputted from a simulated feedback voltage generator 14 by an adder 15. Any output voltage or output current from a power supply 6 is controlled by means of comparing the sum of feedback outputted from the adder 15 with any specified laser beam set up signal by a comparator 11 and outputting the compared value as laser output directive value from the comparator 11 to a power supply 6 through the intermediary of an amplifier 12. Therefore, any excessive output in case of starting a laser oscillator may be prevented from being transmitted since any delayed response speed of the laser beam detector 10 is corrected by the simulated feedback.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a laser output control device for controlling the output of a laser oscillator, and particularly to one for controlling the large output generated at the start.

[Prior art]

When controlling the output of a laser oscillator, there is a current i usage method that detects the discharge current that excites the laser medium and controls this discharge current, and an output detection method that detects the output of the laser oscillator and controls the discharge current. There is.

Figure 6 is a schematic configuration diagram showing a conventional output control device for a laser oscillator using the current detection method. A laser medium gas such as carbon dioxide gas is flowing between the plates (2). (3) is a partially transmitting mirror that outputs the laser beam (4), (6) is a total reflection mirror, (6) is a power source with a discharge current conversion circuit, and (7) is an anode plate (1) and a cathode plate (2). ), and (8) is a comparator that compares the detected current signal of the current detector (7) with the set current signal (9) output from a current setter (not shown). be.

In the laser output control device configured as described above,
A power source (6) supplies a discharge current between the anode plate (1) and the cathode plate (2) to excite the laser medium gas.

The laser light emitted from this laser medium gas is resonated by a partially transmitting mirror (3) and a fully reflecting mirror (5) that are placed opposite each other.
A partially transmitting mirror (3) outputs a laser beam (4).

The intensity of the laser beam (4) is controlled to be approximately constant by keeping the excitation intensity of the laser medium gas constant.

In other words, the current t11 discharged from the power supply (6) is detected by the current detector (7).
) and output from the current detector (7), and a set current signal (9) that is set to a predetermined value in advance.
) is compared with the comparator (8), and the deviation signal is used to calculate the
i. Controlling the current.

However, in the laser output control device described above,
Rather than returning the output of the laser beam (4) itself,
Since the discharge current is detected and fed back, a problem arises in that it is difficult to maintain a constant output of the laser light (4), which is affected by the gas flow rate, gas pressure, gas deterioration, etc. of the laser medium gas. .

In order to solve this problem, FIG. 4 shows a conventional laser output control device that directly detects the output of a laser oscillator and controls the discharge current according to the output of the laser beam. In the figure, the same reference numerals as the apparatus shown in FIG. 6 indicate the same books. (5A) is a total reflection mirror that reflects most of the #1 laser beam but transmits about 1 factor. α1 is total reflection ill (detection laser beam transmitted through 5Al (4A)
The laser light detector is made of, for example, a salmon pile, and outputs a voltage corresponding to the intensity of the laser light (4A). (b) is a comparator, and (2) is an amplifier.

In the laser output control device configured as described above, the detected laser beam (4A) proportional to the intensity of the laser beam (4) is detected by the laser beam detector αQ, this is converted into an electric signal, and this output and a predetermined The comparator c19 compares the laser beam setting signal (to) with the laser beam setting signal (to), and the deviation signal is sent to the amplifier (b).
and controlling the excitation intensity of the laser medium gas by controlling the output voltage or output current of the power source (6),
This controls the intensity of the laser beam (4) to be approximately constant.・In this case, the detection laser beam (4A) is detected and the laser output is controlled, so the influence of disturbances such as the flow velocity of the laser medium gas is small, but the laser light detector that detects the detection laser beam (4A) Since (11) is made of salmon pile or the like, there is a drawback that the response speed is slow. For this reason, the fifth
As shown in the waveform diagram in the figure, there is a delay in the laser output feedback amount when the laser oscillator starts operating, and a delay also occurs in the laser output command value from the comparator αη, causing the laser output to become larger than necessary at the start. However, due to the problem that laser processing defects are likely to occur, conventionally, a current detection method that is largely affected by disturbances has been mainly used.

[Summary of the invention]

The present invention has been made for the purpose of improving this problem, and includes a laser output control device that detects the output of a laser beam and controls the output of the laser beam by feeding back this detection signal. A simulated feedback voltage generator is provided that generates a simulated feedback amount such that the sum of the output feedback amount of the laser beam and the output feedback amount of the laser beam is constant at the start of operation, and the simulated feedback amount output from this simulated feedback voltage generator and the output feedback of the laser beam are This invention proposes a laser output control device that prevents the generation of excessive output at the start of operation of a laser oscillator by controlling the excitation intensity of the laser medium based on the signal obtained by adding the amounts.

[Embodiments of the invention]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.
In the figure, the same reference numerals as in the conventional device described above are the same. α◆ is a simulated feedback voltage generator that outputs an output in response to the operation start signal (2) of the laser oscillator. The sum of the simulated feedback voltage generator a4 and the amount of laser output feedback from the laser light detector (6) outputted in response to the set value (6) of the laser light output signal at the start of operation of the laser oscillator is constant. Reference numeral 1 (c) which outputs the simulated feedback amount is an adder which adds the laser output feedback amount and the simulated feedback amount and outputs the result to the comparator (l]).

In the laser output control device configured as above, as shown in the waveform diagram in Fig. 2, the detected laser beam (4A) emitted from the total reflection mirror (5A) to the laser photodetector α0~ By adding the simulated feedback amount output from the feedback voltage generator α→ in an adder (6), a delay in the response speed of the laser photodetector αQ that can be measured at the start of operation of the laser oscillator is corrected. This adder Q
The sum of the feedback amount output from θ and a predetermined laser beam setting signal are compared by a comparator α, and the comparator 01) outputs the laser output command value to the power supply (6) via the amplifier (6). Controls the output voltage or output current of the stain source (6). Therefore, even if the response speed of the laser photodetector 0Q is slow, this delay in response speed is corrected by the simulated feedback amount, making it possible to prevent the generation of excessive output at the start of operation of the laser oscillator. A laser output of constant intensity can be obtained from the start.

〔Effect of the invention〕

As explained above, this invention corrects the amount of feedback of the laser output with the amount of simulated feedback at the start of operation of the laser oscillator,
By preventing the generation of an unnecessarily large laser output when the laser oscillator starts operating, it is possible to eliminate processing defects at the start of operation, resulting in stable processing from the start. has.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, FIG. 2 is a waveform diagram of the embodiment shown in FIG. 1, and FIG. 3 is a diagram. Figure 4 is a schematic configuration diagram of a conventional laser output control device;
This figure is a waveform diagram of the laser output control device shown in FIG. 4. (1)... Anode plate, (2)... Cathode plate, (3)...
・Partially transmitting mirror, (4)...Laser source, (4A)...
Detection laser beam, (5), (5A)... Total reflection mirror, (
6)...power supply, (7)...current detector, (8),
ell)...Comparator, (9)...Setting current signal,
αO...Laser photodetector, (2)...Amplifier, (To)...Setting signal, 口◆...Simulated feedback voltage generator, (
6)... Adder, α6... Start signal. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Patent Attorney Sanro Kimura Figure 3 112 Figure 5

Claims (1)

[Claims] In a laser output control device that detects the output of a laser beam and controls the output of the laser beam by feeding back this detection signal, the sum of the output and feedback amount of the laser beam becomes constant at the start of operation of the laser oscillator. A simulated feedback voltage generator that generates a simulated feedback amount, an adder that adds the laser beam output feedback amount and the simulated feedback amount, and a comparator that compares the output of this adder with a predetermined laser beam output command value. and,
A laser output control device whose function is to control the excitation intensity of a laser medium.