JP2013110212A - Laser source driving device, laser oscillator and laser processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser source driving device, a laser oscillator and a laser processing device capable of switching light beam from a laser source between short pulse and long pulse.SOLUTION: In a condition that a first power switch 20 is ON and a second power switch 23 is OFF, when the switching element 22 is turned ON/OFF, a CR circuit 27 (capacitor 26) is turned ON/OFF and a laser diode 7 outputs a laser beam at short pulse using the CR circuit 27 as the power supply. Contrary, in a condition that the first power switch 20 is OFF and the second power switch 23 is ON, when the switching element 22 is turned ON/OFF, the laser diode 7 outputs a laser beam at long pulse using the main power +V as the power source. With this, the pulse width of the laser beam can be switched to either one of the short pulse and the long pulse.

Description

  The present invention relates to a laser light source driving device, a laser oscillator, and a laser processing device for driving a laser light source.

  Conventionally, in the field of laser marking devices, since there are a wide variety of types of laser output required, a laser diode serving as a seed light source is driven at high speed, and the output light (seed laser light) of the laser diode is reduced to a desired short wavelength. There is a need to output even a pulse. For this reason, in recent years, various laser diode drivers for driving a laser diode at high speed have been developed (see Patent Documents 1 and 2, etc.).

  However, the laser diode drivers of Patent Documents 1 and 2 need to be configured inside an integrated circuit (IC), for example, and it is necessary to design a dedicated IC in-house or purchase a dedicated IC from another company. This leads to problems that the circuit configuration becomes complicated and the cost of parts increases. Further, if the configuration does not use an integrated circuit, it is necessary to use, for example, a special purpose electronic device, for example, a compound semiconductor device such as GaAs or GaN which is not silicon, which also increases the complexity of the circuit configuration and increases the component cost. I am concerned about the problem.

JP 2002-111118 A JP 2003-17800 A

  For example, FIG. 9 shows a laser diode driver 81 that does not use a dedicated IC. In the case of this circuit configuration, since the general-purpose IC 82 is used, the component cost is low. However, in this type of laser diode driver, there is a need to switch the pulse width of the seed laser light with a short pulse or a long pulse. However, in the case of the circuit configuration of FIG. There arises a problem that the laser diode cannot be driven. For example, when it is desired to set the pulse width to 10 ns, the limit is actually about 20 to 200 ns.

  Therefore, for example, when high-speed driving of a laser diode is required without using a dedicated IC, a laser diode driver 84 using charging / discharging of a capacitor 83 as shown in FIG. However, in this circuit configuration, since the pulse width of light is determined by the CR time constant, seed laser light can be output in a short pulse (about 10 ns), but on the contrary, a long pulse is not rectangular and is desired. As a result, it is difficult to increase the pulse width.

  An object of the present invention is to provide a laser light source driving device, a laser oscillator, and a laser processing device capable of switching light from a laser light source to either a short pulse or a long pulse.

  In order to solve the above-mentioned problems, in the present invention, a charge / discharge element capable of charging / discharging the main power supply in a laser light source driving apparatus that oscillates a laser light source and emits pulsed light from the laser light source. And a switching element for turning on / off the laser light source, a first mode for outputting the light in a short pulse by switching a switch state of a power switch means to control the charge / discharge element, and the light for a long time. Mode setting means for switching to any one of the second modes to be output in pulses, and control means for outputting the light in short pulses or long pulses in each mode described above by switching on / off of the switching element; The main point is that

  According to the configuration of the present invention, it is possible to output at least a short pulse of laser light from the laser light source by pulse-oscillating the laser light source using charging / discharging of the charge / discharge element as a power source. Then, utilizing the fact that the laser light source can output short-pulse light in this way, the drive mode of the laser light source driving device can be output in the first mode in which light can be output in a short pulse, and light can be output in a long pulse. It is possible to switch to the second mode. Therefore, the pulse width of the laser light can be appropriately switched to either a short pulse or a long pulse according to the usage situation.

  In the present invention, the mode setting means sets the drive mode of the laser light source to the first mode by switching the switch state of the power switch means to enable the charge / discharge operation of the charge / discharge element, The drive mode is set to the second mode by switching the switch state of the power switch means to another to invalidate the charge / discharge operation of the charge / discharge element, and the control means is configured to perform the operation in the first mode. By alternately switching on / off the switching element while the charging / discharging element is in an active state, the charging / discharging element is repeatedly charged and discharged, and the light is output to the charging / discharging element as a power source in a short pulse. And switching the switching element on and off alternately while the charge / discharge element is disabled during the second mode. And summarized in that to output the serial light long pulse. According to this configuration, the first mode is a mode in which the laser light source is driven by using the charge / discharge element as a power source, and the second mode is a mode in which the laser light source is driven by using the main power source as a power source. For this reason, in both the first mode and the second mode, the laser light source can be oscillated with a pulse equivalent to a rectangular wave, so that a high-quality laser with uniform peak power can be output. Become. Note that the peak power corresponds to a threshold value for destroying the workpiece, and if it is provided, it leads to an advantage that high quality machining is possible.

  The gist of the present invention is that the charge / discharge element comprises a CR circuit having a capacitor and a resistor, and the resistor is a bias resistor of the main power supply. According to this configuration, it is not necessary to separately provide the resistance component of the CR circuit and the bias resistance of the main power supply, and therefore, the effect is high in simplification of the circuit configuration and reduction of component costs.

  In the present invention, an input means for inputting a pulse width is provided, and the control means takes the first mode when the pulse width input by the input means is less than a certain threshold value, and when the pulse width is equal to or larger than the threshold value. The mode setting means is controlled to switch the mode so as to take the second mode, and the light is output with a short pulse or a long pulse and with a pulse width input by the input means. To do. According to this configuration, the user can arbitrarily set the pulse width by inputting the pulse width using the input means.

  In the present invention, in a laser oscillator that oscillates a laser light source, outputs pulsed light from the laser light source, amplifies the light with an amplifier, and emits the light, a charge / discharge element capable of charging / discharging the charge of the main power supply A switching element for turning on / off the laser light source, and a first mode for outputting the light in a short pulse by controlling a charging / discharging operation of the charging / discharging element by switching a switch state of a power switch means, When the mode setting means for switching to one of the second modes for outputting the light in a long pulse, the input means for inputting a pulse width, and the pulse width input by the input means are less than a certain threshold value The mode setting means is controlled to switch the mode so that the first mode is taken and the second mode is taken when the threshold is equal to or higher than the threshold value, and the light is changed into a short pulse or a long pulse. Scan in, and is summarized in that with a control means for outputting a pulse width which is input by the input means.

  In the present invention, laser processing is performed in which a laser light source is pulsated to output pulsed light from the laser light source, and the light is amplified by an amplifier and the amplified light is emitted to a workpiece while being scanned by a head. In the apparatus, a charge / discharge element capable of charging / discharging the charge of the main power supply, a switching element for turning on / off the laser light source, and switching a switch state of the power switch means to control a charge / discharge operation of the charge / discharge element. The mode setting means for switching between the first mode for outputting the light in a short pulse and the second mode for outputting the light in a long pulse, the input means for inputting a pulse width, and the input means The mode setting means is configured to take the first mode when the input pulse width is less than a certain threshold and to take the second mode when the pulse width is greater than or equal to the threshold. Switching the mode by us, the light, the short pulsed or long pulse, and the gist that a control means for outputting the input pulse width by the input means.

  According to the present invention, the light from the laser light source can be switched to either a short pulse or a long pulse.

The block diagram of the laser marking apparatus of 1st Embodiment. The timing chart which shows the output waveform of various lights. FIG. 4 is a circuit diagram when the laser light source driving device is in a short pulse mode, where (a) is a circuit diagram during capacitor charging, and (b) is a circuit diagram during capacitor discharging. The circuit diagram when a laser light source drive device is a long pulse mode. FIG. 6 is a circuit diagram when the laser light source driving device of the second embodiment is in a short pulse mode, where (a) is a circuit diagram when charging a capacitor, and (b) is a circuit diagram when discharging a capacitor. The circuit diagram when a laser light source drive device is a long pulse mode. FIG. 6 is a circuit diagram when the laser light source driving device of the third embodiment is in a short pulse mode, where (a) is a circuit diagram when charging a capacitor, and (b) is a circuit diagram when discharging a capacitor. The circuit diagram when a laser light source drive device is a long pulse mode. The circuit diagram of the conventional laser diode driver. FIG. 6 is a circuit diagram of another conventional laser diode driver.

(First embodiment)
A laser light source driving device according to a first embodiment of the present invention will be described below with reference to FIGS.

  As shown in FIG. 1, the laser marking device 1 includes a laser oscillator 3 that generates a source of laser light to be irradiated onto the workpiece 2, and a laser beam emitted from the laser oscillator 3 is modulated to scan the workpiece 2. A head 4 for irradiation is provided. Further, the laser marking device 1 is provided with a controller 5 for controlling the operation of the laser marking device 1 and a console 6 serving as an operation panel. The laser marking device 1 corresponds to a laser processing device, the head 4 corresponds to an optical scanning unit, and the console 6 corresponds to an input unit.

  The laser oscillator 3 includes a laser diode (LD) 7 serving as a seed light source for laser output, and an amplifier 8 for amplifying light output from the laser diode 7 (hereinafter referred to as seed laser light Sa). It has been. The laser diode 7 is connected to the controller 5 via a driver 9 in the laser oscillator 3. The controller 5 drives and controls the driver 9 to cause the laser diode 7 to oscillate (intermittently drive) and to output the pulsed seed laser light Sa shown in FIG. The laser diode 7 corresponds to a laser light source.

  As shown in FIG. 1, the amplifier 8 is provided with an optical isolator 10 that allows light to pass only in a single direction, and a pumping semiconductor laser 11 that amplifies the seed laser light Sa of the laser diode 7. The pumping semiconductor laser 11 is connected to the controller 5 via a driver 12 in the amplifier 8. The controller 5 controls the driver 12 to output light of constant intensity shown in FIG. 2 (hereinafter referred to as excitation laser light Sb) from the excitation semiconductor laser 11.

  As shown in FIG. 1, the amplifier 8 is provided with a multiplexer 13 for coupling the seed laser beam Sa and the excitation laser beam Sb. The multiplexer 13 brings the seed laser light Sa into an excited state by multiplexing the seed laser light Sa with the pump laser light Sb. The multiplexer 13 is connected to a fiber (rare earth doped optical fiber) 14 that amplifies the light combined by the multiplexer 13 by stimulated emission. The fiber 14 outputs the amplified light shown in FIG. 2 (hereinafter referred to as amplified light Sc) to the head 4. The head 4 adjusts the amplified light Sc, and irradiates the workpiece 2 while scanning the laser beam after the adjustment, thereby processing the workpiece 2.

  As shown in FIG. 1, the console 6 is provided with a display 15 made of, for example, a liquid crystal screen. The display unit 15 displays, for example, various setting screens for setting the operation mode of the laser marking device 1 and an operation screen for displaying the current operation state of the laser marking device 1. In addition, the console 6 is provided with an operation unit 16 that is operated when setting various operation modes of the laser marking device 1. The operation unit 16 includes, for example, a power button, a numeric keypad, and a mode input button.

  In the laser marking device 1 of the present example, the seed laser beam Sa can be output with a short pulse (about 10 ns), and when the seed laser beam Sa is output with a long pulse, the seed laser beam Sa can be output variably. A laser light source driving device (laser diode driver) 17 is provided. In the case of this example, the laser diode 7 is driven by a short pulse mode (state of FIG. 3) in which the pulse width of one pulse of the seed laser beam Sa is shortened (about 5 ns) and output. Laser output is possible in the long pulse mode (state shown in FIG. 4) in which the pulse width of one pulse is increased (about 20 to 200 ns) and the pulse width of the seed laser beam Sa is further increased in the long pulse mode. It is variable. In addition, the laser light source driving device 17 of this example is constructed with an inexpensive element by combining discrete components.

  In the laser marking apparatus 1 of this example, the pulse width of the laser output can be selected and set by operating the console 6 and inputting the pulse width of the laser output directly. In this example, when a short pulse is input, that is, when the input pulse width is less than the threshold, the operation mode is referred to as a short pulse mode, and when a long pulse is input, that is, the input pulse width is greater than or equal to the threshold. The operation mode is generally referred to as a long pulse mode.

  As shown in FIGS. 3 and 4, the driver 9 is provided with a current path switching circuit 19 that switches a current path flowing through the laser diode 7. The current path switching circuit 19 will be described in detail below. The current path switching circuit 19 includes a series circuit of a first power switch 20, a resistor 21 and a switching element 22, and a midpoint between the resistor 21 and the switching element 22. P <b> 1 is connected to the cathode terminal of the laser diode 7. The first power switch 20 constitutes a power switch means.

  The first power switch 20 is connected to the main power supply + V and is used as a switch that is turned on when the operation mode of the laser marking device 1 is set to the short pulse mode. The resistor 21 is for voltage bias on the first power switch 20 side. The switching element 22 is connected to the controller 5 and controlled to be turned on / off by the controller 5. That is, when the controller 5 performs switching control of the laser diode 7, the pulsed seed laser light Sa is output from the laser diode 7.

  The current path switching circuit 19 is provided with a series circuit of a second power switch 23 and a resistor 24, and the open end of the resistor 24 is connected to the anode terminal of the laser diode 7. The second power switch 23 is connected to the main power source + V and is used as a switch that is turned on when the operation mode of the laser marking device 1 is set to the long pulse mode. The resistor 24 is for voltage bias on the second power switch 23 side, and its value is determined by the limited current value in the long pulse mode. A backflow preventing diode 25 is connected between the anode terminal and the cathode terminal of the laser diode 7. The diode 25 is connected to the laser diode 7 in parallel and in the opposite direction. The second power switch 23 constitutes a power switch means, and the resistor 24 constitutes a resistance component and a bias component.

  A capacitor 26 that can charge and discharge the voltage of the main power supply + V is connected to the second power switch 23 in parallel. The capacitor 26 of this example forms a CR circuit 27 with the resistor 24 and serves as a power source for the laser diode 7 when the operation mode is the short pulse mode. That is, as shown in FIG. 3, in the short pulse mode, the CR circuit 27 is charged and discharged in a short time by switching the switching element 22 on and off, and the generated charge is supplied to the laser diode 7 as a power source. Is pulse-oscillated. The capacitor 26 can be charged / discharged in the short pulse mode by the diode 25 connected in parallel and in the opposite direction to the laser diode 7. Further, the capacitor 26 is set to a capacitance value determined from a time constant that becomes necessary when the value of the resistor 24 is determined. The resistor 24 is shared by the second power switch 23 for bias and the CR circuit 27. When the CR circuit 27 is used as a power source, the pulse width of the laser diode 7 is determined by the time constant τ of the CR circuit 27. The CR circuit 27 corresponds to a charge / discharge element.

  As shown in FIG. 1, the controller 5 is provided with a mode setting unit 28 that sets the operation mode of the laser marking device 1 to a mode corresponding to the pulse width input from the console 6. The mode setting unit 28 takes in the input data of the pulse width input from the console 6 and sets the operation mode based on this data. In the case of this example, for the sake of convenience, the operation mode when a short pulse (about 5 ns) is input as a pulse width is referred to as a short pulse mode, and a long pulse (one value within about 20 to 200 ns) is input as a pulse width. The operation mode is generally referred to as a long pulse mode. The mode setting unit 28 constitutes mode setting means.

  As shown in FIG. 3, the mode setting unit 28 sets the operation mode to the short pulse mode by turning on the first power switch 20 and turning off the second power switch 23. At this time, the CR circuit 27 becomes effective, and the CR circuit 27 can operate as a power source for the laser diode 7. On the other hand, as shown in FIG. 4, the mode setting unit 28 sets the operation mode to the long pulse mode by turning off the first power switch 20 and turning on the second power switch 23. At this time, the CR circuit 27 becomes invalid, the CR circuit 27 does not work as a power source, and the main power source + V becomes the power source of the laser diode 7.

  The controller 5 is provided with a switching control unit 29 that controls on / off switching of the switching element 22. In the short pulse mode, the switching control unit 29 charges and discharges the capacitor 26 with the time constant τ of the CR circuit 27 by switching the switching element 22 on and off, and uses the charge of the capacitor 26 as a power source for the laser diode 7. Make a pulse oscillation. In the long pulse mode, the switching control unit 29 causes the laser diode 7 to oscillate by using the main power source + V on the second power switch 23 side as a power source by switching the switching element 22 on and off. In the long pulse mode, the switching control unit 29 can switch the pulse width of the laser in the long pulse mode by changing the ON / OFF switching timing of the switching element 22. The switching control unit 29 corresponds to control means.

Next, the operation of the laser light source driving device 17 of this example will be described with reference to FIGS.
For example, it is assumed that a short pulse less than a threshold value is input as a laser beam pulse by the operation unit 16 of the console 6. In the short pulse mode, the mode setting unit 28 turns on the first power switch 20 and turns off the second power switch 23 as shown in FIG. As a result, the charging / discharging operation of the CR circuit 27 by the main power supply + V becomes effective. That is, the capacitor 26 can be charged with the voltage of the main power source + V and the charged electric charge can be discharged, and the CR circuit 27 functions as a power source for the laser diode 7.

  The switching control unit 29 charges and discharges the capacitor 26 by switching the switching element 22 on and off. At this time, as shown in FIG. 3A, when the switching element 22 is turned on, the charging current Ich flows through the CR circuit 27 and the laser diode 7, and the laser diode 7 is driven. Further, as shown in FIG. 3B, when the switching element 22 is turned off, a discharge current Idc flows through the diode 25 and the CR circuit 27. By repeatedly switching the switching element 22 on and off, the capacitor 26 is repeatedly charged and discharged, and a short pulse (pulse width: about 5 ns) seed laser beam Sa is emitted from the laser diode 7 by the charging and discharging current. The

  In the short pulse mode, the switching control unit 29 switches on / off of the switching element 22 with an arbitrary value. That is, the switching control unit 29 in the short pulse mode repeats on / off with the on-time of the switching element 22 being an arbitrary value (for example, about 200 ns) and the next turn-on timing as a repetition period. As a result, a laser beam having a short pulse (pulse width: about 5 ns) is output from the laser diode 7.

  Subsequently, for example, it is assumed that one value of a long pulse that is equal to or greater than a threshold value is input as a laser beam pulse by the operation unit 16 of the console 6. In the long pulse mode, as shown in FIG. 4, the mode setting unit 28 turns off the first power switch 20 and turns on the second power switch 23. As a result, the charge / discharge operation of the CR circuit 27 becomes invalid. That is, the capacitor 26 does not function, and the capacitor 26 cannot be charged / discharged.

  In the long pulse mode, the switching control unit 29 switches on / off of the switching element 22 at a timing according to the value of the input pulse. That is, the switching control unit 29 in the long pulse mode repeats on / off with the on-time of the switching element 22 as the pulse width and the pairing to be turned on next as a repetition cycle.

  As a result, a long pulse (pulse width: 20 to 200 ns) seed laser beam Sa is emitted from the laser diode 7 using the main power source + V as a power source. That is, when the switching element 22 is turned on, the drive current Ivc flows through the laser diode 7, and the laser diode 7 is driven. When the switching element 22 is turned off, the drive current Ivc does not flow through the laser diode 7, The operation is repeated. As a result, a laser beam having a long pulse (pulse width: one value of 20 to 200 ns) is output from the laser diode 7.

  As described above, in this example, the CR circuit 27 (capacitor 26) functioning as a power source for the laser diode 7 is provided in the circuit, and the switching element 22 is turned on / off to switch the charging / discharging of the capacitor 26 for charging. A discharge current is passed through the laser diode 7 so that the laser diode 7 can oscillate in pulses. In this case, since the pulse width of the laser light from the laser diode 7 is determined by the time interval of the time constant τ of the CR circuit 27, the laser light can be output as a short pulse.

  In the case of this example, the laser light source driving device 17 is driven in a short pulse mode in which the laser diode 7 is pulse-oscillated using the charge of the capacitor 26 as a power source and a short pulse laser beam is output, and the main power source + V is the power source. The laser diode 7 can be switched to either the long pulse mode in which the laser diode 7 is oscillated to output a long pulse laser beam. For this reason, the light of the laser diode 7 can be freely set to either a short pulse or a long pulse.

  In the long pulse mode, the pulse width of the laser beam can be varied in the range of 20 to 200 ns in the long pulse mode by changing the switching time (switching timing) of the switching element 22. did. For this reason, even in the long pulse mode, the pulse width of the laser light can be switched to various values, so that the laser light can be set to a desired pulse width in accordance with the use situation.

According to the configuration of the present embodiment, the following effects can be obtained.
(1) The driving mode of the laser light source driving device 17 includes a short pulse mode in which the laser diode 7 is oscillated with a short pulse width by turning the switching element 22 on and off using the capacitor 26 as a power source, and a switching element using the main power source + V as a power source The laser diode 7 can be switched to either a long pulse mode in which the laser diode 7 is oscillated with a long pulse width by turning on / off 22. Therefore, the pulse width of the laser light can be freely switched as appropriate to either a short pulse or a long pulse.

  (2) When the laser diode 7 is pulse-oscillated using the capacitor 26 of the CR circuit 27 as a power source, the pulse of the laser light takes a waveform in accordance with the time constant τ of the CR circuit 27, so that the rise is steep and the output is gradually increased. Take a waveform that declines rapidly. By the way, when the laser beam is used for processing applications, the pulse shape of the laser beam corresponds to the peak power. However, since this peak power is directly related to the processing quality, it is desirable to be constant. In the case of this example, in the short pulse mode, the laser diode 7 is oscillated with a substantially triangular pulse whose one point determined by the time constant τ of the CR circuit 27 is steeply high. This is necessary in the short pulse mode. Since the pulse is as short as about 10 ns, even a pulse waveform conforming to the CR circuit 27 can be handled as a waveform close to a rectangle. Therefore, in the short pulse mode, there is no problem even if the laser diode 7 is driven using the CR circuit 27 as a power source. On the other hand, in the long pulse mode, a rectangular wave having a long pulse width is required. However, in the long pulse mode, the laser diode 7 is oscillated with the main power source + V as the power source. For this reason, in both the short pulse mode and the long pulse mode, the laser diode 7 can be pulse-oscillated with a pulse corresponding to a rectangular wave, so that a laser with uniform peak power can be obtained. Since the peak power corresponds to a threshold value for destroying the workpiece, if the peak power can be made uniform in this way, it leads to an advantage that high quality processing can be performed.

  (3) In the long pulse mode, the pulse width can be further switched within one mode by changing the ON / OFF switching timing of the switching element 22. Therefore, laser light having various pulse widths can be output as appropriate according to the usage situation. In the short pulse mode, if the time constant of the CR circuit 27 is changed, the pulse width can be appropriately changed to a desired value even in the short pulse mode.

  (4) The resistance 24 of the CR circuit 27 is shared by the resistance component of the CR circuit 27 and the bias resistance of the main power source + V. For this reason, it is not necessary to separately provide the resistance component of the CR circuit 27 and the bias resistance of the main power source + V, so that the effect of simplification of the circuit configuration and reduction of component costs is enhanced.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. This example is an example in which the circuit configuration of the current path switching circuit 19 is changed to another configuration, and the basic part is the same as that of the first embodiment. Therefore, the same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof is omitted, and only different parts will be described.

  As shown in FIGS. 5 and 6, a CR circuit 27 and a third power switch 30 are connected between the anode terminal of the laser diode 7 and the ground. Between the laser diode 7 and the middle point P2 of the capacitor 26 and the second power switch 23, a resistor 31 dedicated to the power supply bias of the second power switch 23 is connected. The resistor 32 of the CR circuit 27 is a dedicated resistor for the CR circuit 27. The third power switch 30 constitutes power switch means, and the resistor 32 corresponds to a resistance component dedicated to the CR circuit.

  In the short pulse mode, as shown in FIG. 5, the first power switch 20 and the third power switch 30 are turned on, and the second power switch 23 is turned off. In this state, when the switching element 22 is turned off as shown in FIG. 5A, the charging current Ich flows through the laser diode 7, and conversely, as shown in FIG. When is turned on, a discharge current Idc flows through the laser diode 7. Therefore, by repeatedly turning on / off the switching element 22, a charging / discharging current is caused to flow through the laser diode 7, and the laser diode 7 is pulse-oscillated with a short pulse (about 5 ns).

  In the long pulse mode, as shown in FIG. 6, the first power switch 20 and the third power switch 30 are turned off, and the second power switch 23 is turned on. In this state, as shown in the figure, the switching element 22 is repeatedly turned on and off, and the drive current Ivc is intermittently passed through the laser diode 7, thereby causing the laser diode 7 to have a long pulse (within 20 to 200 ns). 1 value).

According to the configuration of the present embodiment, in addition to (1) to (3) described in the first embodiment, the following effects can be obtained.
(5) Since the resistor 32 of the CR circuit 27 and the power supply bias resistor 31 of the main power supply + V are provided as separate components, the main power supply + V on the second power supply switch 23 side and the resistors 31 and 32 The value can be set easily.

(Third embodiment)
Next, a third embodiment will be described with reference to FIGS. This example is also an example in which the circuit configuration of the current path switching circuit 19 of the first embodiment is changed to another configuration, and only different parts will be described.

  As shown in FIGS. 7 and 8, the CR circuit 27 is connected between the midpoint P <b> 1 of the resistor 21 and the switching element 22 and the cathode terminal of the laser diode 7. The second power switch 23 is connected in parallel to the capacitor 26 of the CR circuit 27.

  In the short pulse mode, as shown in FIG. 7, the first power switch 20 is turned on and the second power switch 23 is turned off. In this state, when the switching element 22 is turned off as shown in FIG. 7A, the charging current Ich flows through the laser diode 7, and conversely, as shown in FIG. When is turned on, a discharge current Idc flows through the laser diode 7. Therefore, by repeatedly turning on / off the switching element 22, a charging / discharging current is caused to flow through the laser diode 7, and the laser diode 7 is pulse-oscillated with a short pulse (about 5 ns).

  In the long pulse mode, as shown in FIG. 8, the first power switch 20 is turned off and the second power switch 23 is turned on. In this state, as shown in the figure, the switching element 22 is repeatedly turned on and off, and the drive current Ivc is intermittently passed through the laser diode 7, thereby causing the laser diode 7 to have a long pulse (within 20 to 200 ns). 1 value).

According to the configuration of this embodiment, in addition to (1) to (4) described in the first embodiment, the following effects can be obtained.
(6) The pulse width of the laser light can be switched to either a short pulse or a long pulse even in a circuit configuration other than the first embodiment or the second embodiment.

Note that the embodiment is not limited to the configuration described so far, and may be modified as follows.
In each embodiment, the charge / discharge element is not limited to the CR circuit 27. For example, a capacitance (capacitor) that exists as a parasitic element of a semiconductor device (a transistor or the like) may be used.

  In each embodiment, various transistors can be used as the switching element 22. The switching element 22 is not limited to a transistor, and other elements may be used.

  In each embodiment, the amplifier 8 is not limited to one stage. For example, a plurality of amplifiers may be provided by providing amplifiers at the front and rear stages, respectively. Further, the number of pumping semiconductor lasers 11 is not limited to one, and a plurality of pumping semiconductor lasers 11 may be provided.

  In each embodiment, the power source connected to the first power switch 20 and the power source connected to the second power switch 23 are not limited to taking the same value (+ V), and they may take different values.

  In each embodiment, the element that charges and discharges the capacitor 26 is not limited to the diode 25 described in the embodiment, and may be any element that can limit current, such as a switching element.

  In each embodiment, the laser light source driving device 17 is not limited to being mounted on the laser marking device 1 described in this example, and can be applied to various laser devices.

  DESCRIPTION OF SYMBOLS 1 ... Laser marking apparatus as a laser processing apparatus, 2 ... Work, 3 ... Laser oscillator, 4 ... Head as optical scanning part, 6 ... Console as input means, 7 ... Laser diode as laser light source, 8 ... Amplifier, DESCRIPTION OF SYMBOLS 17 ... Laser light source drive device, 20 ... 1st power switch which comprises power switch means, 22 ... Switching element, 23 ... 2nd power switch which comprises power switch means, 24 ... Resistor 24 which comprises resistance component and bias component , 26 ... capacitor, 25 ... diode constituting mode setting means, 27 ... CR circuit as charge / discharge element, 28 ... mode setting part constituting mode setting means, 29 ... switching control part as control means, 30 ... power supply Third power switch constituting switch means, 32... Resistance as a resistance component dedicated to CR circuit, + V The main power supply.

Claims (6)

In a laser light source driving device that oscillates a laser light source and emits pulsed light from the laser light source,
A charge / discharge element capable of charging / discharging the charge of the main power supply;
A switching element for turning on / off the laser light source;
A mode for switching between a first mode for outputting the light in a short pulse and a second mode for outputting the light in a long pulse by switching the switch state of the power switch means and controlling the charge / discharge element. Setting means;
A laser light source driving device comprising: control means for outputting the light in a short pulse or a long pulse by switching on / off of the switching element under each mode described above. The mode setting means sets the drive mode of the laser light source to the first mode by switching the switch state of the power switch means to enable the charge / discharge operation of the charge / discharge element, and the power switch means By switching the switch state to other and invalidating the charge / discharge operation of the charge / discharge element, the drive mode is set to the second mode,
The control means is configured to cause the charge / discharge element to repeat charge / discharge by alternately switching on / off the switching element under a state where the charge / discharge element is valid in the first mode. The main power is supplied to the power source by causing the device to output the light in a short pulse and alternately switching on / off the switching device in a state where the charge / discharge device is disabled in the second mode. The laser light source driving apparatus according to claim 1, wherein the light is output in a long pulse. The charge / discharge element comprises a CR circuit having a capacitor and a resistor,
The laser light source driving device according to claim 1, wherein the resistor is a bias resistor of the main power source. An input means for inputting a pulse width is provided,
The control means is configured to take the first mode when the pulse width input by the input means is less than a certain threshold and to take the second mode when the pulse width is greater than or equal to the threshold. The mode is switched by controlling the light, and the light is output in a short pulse or a long pulse and with a pulse width input by the input means. Laser light source driving device. In a laser oscillator that pulsates a laser light source to output pulsed light from the laser light source, amplifies the light with an amplifier, and emits the light.
A charge / discharge element capable of charging / discharging the charge of the main power supply;
A switching element for turning on / off the laser light source;
By switching the switch state of the power switch means to control the charge / discharge operation of the charge / discharge element, either the first mode for outputting the light in a short pulse or the second mode for outputting the light in a long pulse Mode setting means for switching between
An input means for inputting a pulse width;
The mode setting means is controlled to change the mode so that the first mode is taken when the pulse width inputted by the input means is less than a certain threshold, and the second mode is taken when the pulse width is more than the threshold. And a control means for switching and outputting the light in a short pulse or a long pulse and with a pulse width inputted by the input means. In a laser processing apparatus that oscillates a laser light source to output pulsed light from the laser light source, amplifies the light with an amplifier, and emits the amplified light to a workpiece while scanning with an optical scanning unit ,
A charge / discharge element capable of charging / discharging the charge of the main power supply;
A switching element for turning on / off the laser light source;
By switching the switch state of the power switch means to control the charge / discharge operation of the charge / discharge element, either the first mode for outputting the light in a short pulse or the second mode for outputting the light in a long pulse Mode setting means for switching between
An input means for inputting a pulse width;
The mode setting means is controlled to change the mode so that the first mode is taken when the pulse width inputted by the input means is less than a certain threshold, and the second mode is taken when the pulse width is more than the threshold. And a control means for switching and outputting the light in a short pulse or a long pulse with a pulse width input by the input means.