JPH0629607A - Laser system - Google Patents

Abstract

PURPOSE:To control the exciting output so that the laser beam output at specific value may be obtained in simple constitution at low cost. CONSTITUTION:The discharge electrodes 2, 3 of a resonator 1 are supplied with exciting output from a high voltage power supply unit 4. This high voltage power supply unit 4 and the resonator 1 are maintained at specific temperature. Besides, the high voltage power supply unit 4 and a cooling unit 5 are drive- controlled by a control unit 6. On the other hand, a photo-sensor 7 detects the intensity of the laser beams emitted from the resonator 1 so as to transmit the detecting signals to the control unit 6. The control unit 6, after finishing the first processing step in the power supply throwing time and the actuation at specific excited output for a specific time, performs the automatic output calibration as the initial setting up actuation. Through these procedures, the automatic calibration can be performed after the laser beam output reaches the stabilized region thereby enabling the laser beam output to be obtained as the accurate value corresponding to the excited output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detection means for detecting a laser light output and a laser light output by the detection means corresponding to an excitation output of a laser medium by performing an initializing operation after turning on a power source. The present invention relates to a laser device having a controller that calculates a value and controls the excitation output so that the laser light output reaches a set value based on the result.

[0002]

2. Description of the Related Art For example, in a gas laser device, a resonator filled with laser gas is provided with a pair of discharge electrodes,
A pumping output is supplied from a high-voltage power supply between the discharge electrodes to cause discharge inside the resonator. This excites the laser gas, and when the generated light is resonated by the resonator, laser light is output by the oscillation action. It is supposed to be done. In this case, the laser light output is generally set indirectly by adjusting the output of the high-voltage power supply.However, since the performance of the resonator deteriorates over time, the excitation of the set high-voltage power supply The same laser light output is not always obtained with respect to the output.

Therefore, conventionally, in order to solve such a problem, an optical sensor for detecting the laser light output is provided, and when the power is turned on, a program as shown in FIG. A process called calibration is performed. That is, when the apparatus is started up, the control apparatus starts the laser oscillation operation to perform the start-up operation (step S1), and then the automatic output calibration is performed (step S2) to complete the oscillation preparation.

In the automatic output calibration described above, the control device sets the excitation output of the high-voltage power source to a plurality of output reference values and detects the laser light output corresponding to each output reference value by an optical sensor. Therefore, the correlation between the two is calculated. With this, the control device can convert and set the value of the excitation output of the high-voltage power supply from the above-mentioned correlation corresponding to the set value of the laser light output by the user, so that the change over time of the resonator Even in some cases, by obtaining and setting the correlation for each use, the error can be reduced as much as possible and the oscillation operation can be performed with a desired laser light output.

[0005]

By the way, as the cause of the fluctuation of the laser light output, in addition to the performance deterioration due to the above-mentioned aging of the resonator, the temperature change and the composition change of the laser gas accompanying the operation of the oscillating device are caused. Etc. That is, in general, when the laser oscillator is continuously operated for a long time based on the output standard of a constant high-voltage power source, the laser light output is, as shown in FIG. After a few minutes to a few hours, some percentage will drop.

Therefore, conventionally, in a state where the laser light output fluctuates in the initial fluctuation region, in order to reduce the error, for example, feedback control is performed to deal with the fluctuation of the laser light output. Is configured. However, since the structure for performing such feedback control becomes complicated and there is a problem that the software needs to be greatly improved, an increase in cost is inevitable as a whole.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to accurately set a pumping output corresponding to a set value of a laser light output while having a simple and inexpensive structure. Another object of the present invention is to provide a laser device capable of obtaining a laser light output in a state where there is no fluctuation according to a set value.

[0008]

According to the present invention, a detecting means for detecting a laser light output, and an initial setting operation after power-on to measure the laser light output by the detecting means corresponding to the excitation output of a laser medium. It is intended for a laser device having a control device for controlling the excitation output so that the laser light output becomes a set value based on the result of calculation of a conversion value, and the control device is the power supply of the power source. The present invention is characterized in that the initial setting operation is performed after operating at a predetermined excitation output for a fixed time from the time of input.

Further, in the above object, there is provided a clocking means for starting a clocking operation when the operation is stopped, and the control device is arranged such that when the clocking time by the clocking means exceeds a predetermined time when the power is turned on, the control device is operated for a predetermined time. The initial setting operation may be performed after the operation with a predetermined excitation output.

[0010]

According to the laser device of the first aspect, the control device operates at a predetermined excitation output for a certain period of time after the power is turned on, and then performs the initial setting operation. As a result, the initial setting operation is performed after the initial fluctuation region at the time of rising when the laser light output becomes unstable.
Then, in this initial setting operation, the control device obtains the correlation of the laser light output from the detection means with respect to the excitation output of the laser medium, and according to the set value of the laser light output set by the user, the excitation output Obtain and set the converted value. In other words, because the initial setting operation is performed avoiding the power-on when the laser light output changes with respect to the pump output,
The correspondence between the two becomes accurate, and the subsequent setting of the pump output with respect to the set value of the laser light output can be performed in a stable state, and accurate control with few errors can be performed.

According to another aspect of the laser device of the present invention, the control device operates at a predetermined excitation output for a predetermined time when the time measured by the time measuring means exceeds a predetermined time when the power is turned on. Since the initial setting operation is performed after that, it is not necessary, for example, when the clocking time has not reached the predetermined time, that is, when the device is short and the operation is almost in the stable region at the time of starting the operation. It is possible to immediately execute the initial setting operation without waiting for, and thus it is possible to quickly control the set laser light output.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG.
It will be described with reference to FIGS. In FIG. 1, which shows a general schematic block configuration, a pair of discharge electrodes 2 and 3 is provided in an oscillator 1, and power is supplied from a high-voltage power supply device 4. A laser gas is sealed inside the oscillator 1, and when the laser gas is excited by the discharge of the discharge electrodes 2 and 3, an oscillation operation is performed and laser light is output.

The resonator 1 and the high voltage power supply device 4 are cooled by the cooling water circulated from the cooling device 5 and are kept at a constant temperature. And the high-voltage power supply device 4
The cooling device 5 is driven and controlled by the control device 6.
The output intensity of the laser light output from the resonator 1 is detected by an optical sensor 7 as a detection means, and the detection signal is given to the control device 6.

The laser light output can be set by the user, and is set by the controller 6 as the set laser light output. In this case, for example, the value of the set laser light output is set to what percentage of the rated output, and the control device 6
The excitation output corresponding to the high-voltage power supply device 4 is calculated and automatically set according to the set laser light output value, as described later.

Next, the operation of this embodiment will be described.
First, when the power is turned on, the control device 6 reads out the pre-stored start-up program and executes the control according to the flowchart shown in FIG. That is, the control device 6 executes a start-up process to perform a laser light oscillation operation (step T1), drives and controls the high-voltage power supply device 4 and the cooling device 5, and is ready to start the operation.
When the start-up process ends, the control device 6 (time t
0), and subsequently in step T2, the warm-up operation is executed.

In this warm-up operation, the control device 6 causes the high-voltage power supply device 4 to oscillate with a predetermined excitation output for a fixed time T (for example, several minutes). In this case, the fixed time T is set to a time that substantially coincides with the period of the initial fluctuation region in which the laser light output easily fluctuates, as shown in FIG. 3, and when this warm-up operation ends (time t1). ), The operating state of the device reaches a stable region in which it is substantially stable.

Subsequently, the control device 6 shifts to step T3 to execute a process of automatic output calibration as an initial setting operation. In this automatic output calibration, the control device 6 sequentially sets the excitation output level V of the high-voltage power supply device 4 in a plurality of stages within a range from, for example, zero to the rated output level, and the laser light output L corresponding to each excitation output level. Is detected by the optical sensor 7 and the correspondence is obtained.

In this case, the excitation output level V is 20% (V1), 40% (V2), 6 with respect to the rated output level.
0% (V3), 80% (V4) and 100% (V5)
It is set in 5 stages. On the other hand, in accordance with such an excitation output, the laser light output L (L1 to L5) has a characteristic that the increase degree decreases as the excitation output of the high-voltage power supply device 4 increases, as shown in FIG. For example, when the pump output V is 80% (V4) of the rating, the rated (100%) laser light output L4 can be obtained.

When the automatic output calibration process is completed (time t2), the controller 6 ends the startup program and completes the laser oscillation preparation. After that, the control device 6 performs an operation such as a polygonal line approximation on the laser light output set value Ls set by the user based on the above-mentioned correspondence relationship and interpolates the excitation power of the high-voltage power supply device 4. Set the output to the appropriate value. This allows the laser light output L to be obtained at a stable output level without changing during operation.

According to this embodiment as described above, after the power is turned on, the control device 6 operates the high-voltage power supply device 4 at a predetermined excitation output for a fixed time (for example, about several minutes), and then performs the automatic output calibration operation. As a result, automatic output calibration can be performed after the initial fluctuation region immediately after the start of operation and within the stable region, and therefore the cost is significantly reduced compared to the feedback control type in both software and hardware. It is possible to reduce the fluctuation to the value of the laser light output Ls set by the user as much as possible and to perform stable and accurate oscillation operation control.

FIG. 5 and FIG. 6 show a second embodiment of the present invention, and the parts different from the first embodiment will be described below. That is, FIG. 5 is a schematic diagram showing the entire configuration, in which a timepiece 8 as a timekeeping means is provided, and a control unit 6 is provided with a detection unit 6a for detecting an operation stop time and the timepiece 8 is connected to the detection unit 6a. There is. The timepiece 8 is driven by another power source such as a battery (not shown), and is adapted to give a time signal to the detection unit 6a of the control device 6 regardless of the operating state of the device.

The control device 6 controls as follows based on the time signal given from the timepiece 8. That is,
The detection unit 6a of the control device 6 stores the time when the device was stopped last time, and when the power is turned on next time,
The operation stop time ts is calculated and obtained based on the time signal given from the clock 8.

When the start-up program shown in FIG. 6 is started, the control device 6 first determines in step P1 whether the operation stop time ts exceeds the predetermined time ta. When the operation stop time ts exceeds the predetermined time ta, the control device 6 determines “YES”, moves to step P2, and performs the warm-up operation for the fixed time T in the same manner as described above. After that, the process proceeds to step P3 of the automatic output calibration, while "NO" is given in step P1.
If it is determined that the automatic output calibration is performed, the program jumps to step P3.

That is, when the operation stop time ts from the last stop of operation to the start of operation is short and the residual heat of the apparatus is substantially sufficient to make warm-up operation unnecessary, this is omitted. Then, the operation efficiency is improved, and unnecessary warm-up operation does not adversely affect the thermal equilibrium state to cause an error in the automatic output calibration.

According to the second embodiment, the same effect as that of the first embodiment can be obtained, and when the apparatus stop time ts is short (ts <ta), the controller 6 causes the worm to warm. Since the up operation is omitted and the process of automatic output calibration is performed later, when the power is turned on, the stop time from the previous time is short, and if it enters the stable area immediately without warm-up operation, it waits unnecessarily. It saves time and improves operating efficiency.

FIG. 7 shows a third embodiment of the present invention, and the difference from the second embodiment will be described below. That is, in this embodiment, when the operation stop time ts detected by the detector 6a after the start of operation is longer than the predetermined time ta (step Q1), step Q
When the operation stop time ts is shorter than the predetermined time tb, the operation proceeds to step Q3 and the warm-up operation is performed for the time T1, and when the operation stop time ts is the predetermined time tb or more <step Q4 After that, the warm-up operation is performed for the time T2 (T2> T1).

As a result, the warm-up operation can be performed at the appropriate time T1 or T2 according to the magnitude of the operation stop time ts, so that the appropriate warm-up operation can be performed while eliminating unnecessary time. Therefore, it is possible to perform more detailed operation control as compared with the second embodiment, and it takes unnecessary time to start up the device, for example, during lunch break or temporary stop for inspection. Can be eliminated and the operating rate can be improved.

In the above embodiment, the timepiece 8 is used as the time measuring means, but the invention is not limited to this, and a backup timer is provided to judge the necessity of warm-up operation based on the signal from this timer. It may be configured.

Further, in the above embodiment, the warm-up operation time is set in two stages of T1 and T2, but the present invention is not limited to this, and the warm-up operation may be further divided into a plurality of stages according to the operation stop time ts. May be.

[0030]

According to the laser device of the first aspect, the control device causes the initialization operation to be performed after the power is turned on and after the operation is performed at a predetermined excitation output for a certain period of time. The light output becomes unstable after the initial fluctuation region at the time of rise, which makes it possible to accurately detect the correlation between the laser light output and the pump output, and to set the laser light output by the user. It is possible to set a precise and accurate laser light output, and it is possible to realize with a simple and inexpensive structure.

According to the laser device of the second aspect, when the stop time of the device clocked by the clocking means exceeds the predetermined time, the control device is operated at the predetermined excitation output for a predetermined time. In the case where the stop time is short and the device enters the stable region immediately, there is an excellent effect that the initial setting operation can be executed promptly without requiring unnecessary time.

[Brief description of drawings]

FIG. 1 is an electrical block diagram showing a first embodiment of the present invention.

[Figure 2] Flow chart of the startup program

FIG. 3 Laser light output time transition characteristic diagram

[Fig. 4] Correlation diagram between pump output and laser light output

FIG. 5 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 6 is a view corresponding to FIG.

FIG. 7 is a diagram corresponding to FIG. 2 showing a third embodiment of the present invention.

FIG. 8 is a view corresponding to FIG. 2 showing a conventional example.

[Fig. 9] Time transition characteristics of laser light output

[Explanation of symbols]

1 is a resonator, 2 and 3 are discharge electrodes, 4 is a high voltage power supply device, 6
Is a control device, 6a is a detection unit, 7 is an optical sensor (detection means), and 8 is a clock (clock means).

Claims (2)

[Claims] 1. A detection means for detecting a laser light output, and an initialization operation after the power is turned on to measure the laser light output by the detection means corresponding to the excitation output of the laser medium to calculate a converted value. In the laser device having a control device for controlling the excitation output so that the laser light output becomes a set value based on, the control device is operated at a predetermined excitation output for a certain period of time after the power is turned on. A laser device characterized by performing an initial setting operation. 2. A detection means for detecting a laser light output, and an initialization operation after the power is turned on to measure the laser light output by the detection means corresponding to the excitation output of the laser medium to calculate a converted value. In the laser device having a control device for controlling the excitation output so that the laser light output becomes a set value based on the above, a time measuring means for starting a time measuring operation when the operation is stopped is provided, and the control device turns on the power. A laser device characterized in that, when the time measured by the time measuring means exceeds a predetermined time, the initial setting operation is carried out after operating for a predetermined time with a predetermined excitation output.