JP3800812B2 - Laser oscillator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser oscillation device that generates laser light.
[0002]
[Prior art]
In recent years, in order to utilize the characteristics of laser light, laser oscillation devices have been used in various fields such as communication, electronics, optical technology, and precision processing.
[0003]
Conventionally, this type of laser oscillation apparatus is generally configured as shown in FIG.
[0004]
The configuration will be described below with reference to the block diagram of FIG.
[0005]
In this laser oscillation device 30, the synchronization control unit 27 combines the pulse signal generated from the pulse oscillation unit 28 and the output signal of the irradiation command unit 43 that determines the timing of irradiation with the laser beam 22 (hereinafter referred to as an output beam). On the other hand, while comparing the preset value of the current value setting unit 42 with the output value of the current detection unit 23, the comparison control unit 29 performs feedback control so that the output value of the current detection unit 23 is stabilized. Then, the pulse output of the synchronization control unit 27 is converted into a pulse signal for driving the switching power supply by the pulse width modulation unit 25 according to the output value of the comparison control unit 29, and power is supplied to the laser resonator 21 from the switching power supply 24. The output beam is irradiated for the command time of the irradiation command unit 43.
[0006]
The operation of the laser oscillation device 30 will be described with reference to the timing chart of FIG.
[0007]
The signal (B) in FIG. 4 is an output signal from the irradiation command unit 43 and changes from L to H for the time of irradiation of the output beam. Further, the signal (A) is a pulse output signal of the pulse oscillating unit 28, and L, H are constantly repeated at regular intervals. When the signal (A) rises from L to H, the output signal of the irradiation command unit 43 is confirmed. The pulse output signal (D) is output from the synchronization control unit 27 only during the period when (B) is H. Based on this signal (D), the pulse width modulation unit 25 converts it into a triangular wave signal (F), and then converts it into a pulse signal (H) for driving the switching power supply 24 using the output signal (G) of the comparison control unit 29. . When the pulse signal (H) becomes wider, more power is supplied from the switching power supply 24 to the laser resonator 21, so that the intensity of the output beam also increases.
[0008]
[Problems to be solved by the invention]
As described above, in the laser oscillation device 30, when the output signal of the pulse oscillation unit 28 rises from L to H by the synchronization control unit 27, the output signal of the irradiation command unit 43 is confirmed. The synchronous control unit 27 is controlled to output a pulse output signal. In this method, the period of the oscillation frequency of the pulse oscillating unit 28 becomes the resolution (set time interval) of the irradiation command time of the irradiation command unit 43, and the time control of the minute output beam cannot be performed.
[0009]
Further, since the pulse oscillation unit 28 oscillates at the same frequency as the oscillation frequency of the switching power supply 24, the synchronization control unit 27 shows the phase difference between the output signal of the pulse oscillation unit 28 and the output signal of the irradiation command unit 43 in FIG. When the waveform (B) in the timing diagram of FIG. 6 changes as shown in (C), the output signal of the synchronization control unit 27 changes from the waveform (D) to (E), and the number of pulses decreases by one, which is smaller than that of the laser resonator. The irradiation time of the output beam to be output is also shortened.
[0010]
Accordingly, an object of the present invention is to provide a laser oscillation device capable of increasing the setting resolution of the irradiation time of the output beam and simultaneously realizing accurate irradiation reproducibility.
[0011]
[Means for Solving the Problems]
The invention according to claim 1 of the present application (hereinafter referred to as the first invention) includes a pulse oscillating unit that generates a pulse signal, an irradiation command unit that determines the timing of irradiating the output beam, and a pulse signal of the pulse oscillating unit. A synchronization control unit that synthesizes the output signal of the irradiation command unit, a frequency dividing unit that divides the pulse output of the synchronization control unit, a preset value of the current value setting unit, and an output value of the current detection unit The comparison control unit that can feed back the current detection unit so that the output value of the current detection unit becomes stable, and the pulse output of the frequency dividing unit into a pulse signal for driving the switching power supply by the output value of the comparison control unit A pulse width modulation unit for conversion and a switching power source driven by the pulse output of the pulse width modulation unit are provided.
[0012]
The invention according to claim 2 of the present application (hereinafter referred to as the second invention) is an interface that issues an alarm when the pulse width of the pulse width modulation unit exceeds a predetermined value or stops the operation of the apparatus main body. An alarm means for performing a locking operation is provided.
[0013]
Furthermore, an invention according to claim 3 of the present application (hereinafter referred to as a third invention) is characterized by including a gas laser resonator that emits laser light by exciting a laser medium gas by discharge.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
According to the first invention of the present application, since the frequency dividing unit is provided between the synchronization control unit and the pulse width modulating unit, the pulse oscillating unit can be used without increasing the oscillation frequency of the switching power supply that supplies power to the laser resonator. Therefore, the output beam irradiated from the laser resonator can accurately reproduce the irradiation time set in the irradiation command unit.
[0015]
Further, according to the second invention of the present application, when the pulse width of the pulse modulation unit exceeds a predetermined value, an alarm means for performing an interlock operation such as an alarm display or an operation stop of the apparatus is provided. The current value from the power supply can be monitored. As a result, when the current value falls below a predetermined value that cannot be fed back, it is possible to prevent the output beam from being emitted more unstable than the laser resonator.
[0016]
Furthermore, according to the third invention of the present application, since a gas laser resonator is used as the laser resonator, an output beam having good stability and interference can be obtained, and handling becomes easy.
[0017]
(Embodiment)
Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.
[0018]
FIG. 1 is a block configuration diagram of a laser oscillation device 10 according to an embodiment of the present invention. The laser oscillator 10 includes a pulse oscillating unit 8 for generating a pulse signal for driving the switching power supply 4, the laser beam 2 (hereinafter, referred to as the output beam) and the irradiation instruction unit 13 that determines when to irradiate the above a synchronization control unit 7 for synthesizing the pulse signal and output signals above SL emission command section 13 of the pulse oscillation unit 8, a frequency divider 6 for dividing the pulse output of the synchronization control unit 7, a preset current value The setting value of the setting unit 12 and the output value of the current detection unit 3 are compared, and the comparison control unit 9 that feeds back so that the output value of the current detection unit 3 is stabilized, and the pulse output of the frequency dividing unit 6 is A pulse width modulation unit 5 for converting the output value of the comparison control unit 9 into a pulse signal for driving the switching power source 4; a switching power source 4 operating with the output of the pulse width modulation unit 5; Source 4 and a laser resonator 1 which emits a current detection unit 3 and the output beam 2 at a power of from a switching power supply 4 to be detected more current.
[0019]
Further, the laser oscillator 10 includes alarm means 15 for performing an interlock operation such as issuing an alarm or stopping the operation of the apparatus body when the pulse width of the pulse width modulation unit exceeds a predetermined value. ing.
[0020]
In the laser oscillation device 10 having the above configuration, a gas laser resonator using a laser medium gas (for example, CO ₂ gas) is used as the laser resonator 1, and an output beam with good stability and coherence is obtained. However, the present invention is not limited to this, and any type of laser resonator such as a YAG laser resonator may be used as appropriate. Further, in this laser oscillation device 10, a control element is provided in each component and control is performed in each signal processing or each component. However, a CPU connected to each component is provided in the laser resonator 10 and each process is performed. You may make it control collectively.
[0021]
Hereinafter, the output control operation of the output beam 2 in the laser resonator 10 will be described with reference to the timing chart of FIG.
[0022]
A signal (B) in FIG. 2 is an output signal of the irradiation command unit 13 and changes from L to H for the time of irradiation of the output beam. Further, the signal (A) is a pulse output signal of the pulse oscillating unit 8 which is constantly repeating L, H at regular intervals, and when rising from L to H, the output signal of the irradiation command unit 13 is confirmed, and the output signal (B) is output just synchronization controller 7 yo Ri pulse signal (C) period of H. A waveform (D) obtained by dividing the signal (C) by the frequency divider 6 is converted into a triangular wave signal (E) by the pulse width modulation unit 5, and then the switching power supply 4 by the output signal (F) of the comparison control unit 9. Is converted into a pulse signal (G). When the pulse signal (G) becomes wider, more power is supplied from the switching power supply 4 to the laser resonator 1 and the intensity of the output beam 2 becomes stronger.
[0023]
By the way, the oscillation frequency of the normal switching power supply is generally 20 KHz to 40 KHz from the relation of the operation speed of the switching control element (transistor, etc.). The pulse frequency of the pulse oscillation unit 8 is 25 μs to 50 μs (microseconds), and the interval at which the output signal of the irradiation command unit 13 can be processed by the synchronization control unit 7 is also in units of 25 μs to 50 μs. For this reason, the setting resolution of the output beam 2 output from the laser oscillation device 1 is also the above unit interval, and fine control cannot be performed. However, by adding the frequency divider 6, the oscillation frequency of the pulse oscillator 8 can be increased by the magnification of the frequency divider 6, so that fine control is possible and a stable output beam 2 can be obtained. become.
[0024]
As described above, in this embodiment, by adding a frequency divider without increasing the oscillation frequency of the switching power supply, the frequency resolution of the pulse oscillation unit can be increased to improve the time resolution of the output beam, and fine control Became possible.
[0025]
By the way, when the laser oscillation device 10 is used for a long period of time, the laser resonator is caused by factors such as deterioration of the gas for the laser medium in the gas laser resonator 1 used in the present embodiment and air contamination due to a vacuum failure. It is conceivable that the load impedance in 1 changes and it becomes difficult for the current from the switching power supply 4 to flow, and it becomes difficult to stabilize to a preset current value by feedback control. It is also conceivable that feedback control cannot be performed in the same way even when the output line of the switching power supply 4 is disconnected or the power supply is broken due to an unexpected accident . Therefore, the laser oscillation device 10 is provided with an alarm unit 15 that performs an interlock operation when the pulse width of the pulse width modulation unit 5 exceeds a predetermined value . In the present embodiment, the alarm means 15 is an indicator lamp that indicates whether a periodic inspection is necessary, and lights up when the pulse width exceeds a predetermined value. However, the present invention is not limited to this, and the alarm unit 15 may forcibly stop the operation of the laser oscillation device 10 when the pulse width exceeds a predetermined value.
[0026]
【The invention's effect】
As apparent from the above description, according to the first invention of the present application, the frequency of the pulse oscillation unit can be increased without increasing the oscillation frequency of the switching power supply that supplies power to the laser resonator. The output beam emitted from the laser resonator can accurately reproduce the irradiation time set in the irradiation command section.
[0027]
Further, according to the second invention of the present application, when the pulse width of the pulse modulation unit exceeds a predetermined value, an alarm means for performing an interlock operation such as an alarm display or an operation stop of the apparatus is provided. The current value from the power supply can be monitored. As a result, when the current value falls below a predetermined value that cannot be fed back, it is possible to prevent the output beam from being emitted more unstable than the laser resonator.
[0028]
Furthermore, according to the third invention of the present application, since the gas laser resonator is used as the laser resonator, an output beam having a good stability and coherence can be obtained and handling is easy.
[Brief description of the drawings]
FIG. 1 is a block configuration diagram of a laser oscillation device according to an embodiment of the present invention. FIG. 2 is an operation timing diagram of each part in FIG. 1. FIG. 3 is a block configuration diagram of a conventional laser oscillation device. Timing chart of each part
DESCRIPTION OF SYMBOLS 1 Laser resonator 2 Output beam 3 Current detector 4 Switching power supply 5 Pulse width modulation part 6 Frequency division part 7 Synchronization control part 8 Pulse oscillation part 9 Comparison control part 10 Laser oscillation apparatus 12 Current value setting part 13 Irradiation command part 15 Alarm means

Claims (3)

A pulse oscillating unit for generating a pulse signal, an irradiation command unit for determining the timing of irradiating the output beam, a synchronization control unit for synthesizing the pulse signal of the pulse oscillating unit and the output signal of the irradiation command unit, and the synchronization control unit The frequency divider that divides the pulse output of the current and the preset value of the current value setting unit and the output value of the current detection unit are compared, and feedback is made so that the output value of the current detection unit becomes stable. A comparison control unit to be obtained, a pulse width modulation unit for converting the pulse output of the frequency dividing unit into a pulse signal for driving a switching power supply according to an output value of the comparison control unit, and a pulse output of the pulse width modulation unit Oscillation device provided with a switching power supply.   2. An alarm means for providing an alarm when the pulse width of the pulse width modulation unit exceeds a predetermined value or performing an interlock operation for stopping the operation of the apparatus main body is provided. Laser oscillation device.   The laser oscillation apparatus according to claim 1, further comprising a gas laser resonator that emits laser light by exciting a laser medium gas by discharge.

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