Laser oscillator

Abstract

To reduce heat loss without complex circuitry and computational processing.SOLUTION: A laser oscillator 1 includes a laser diode module 3 that emits laser, a drive power supply 5 that applies a drive voltage to the laser diode module 3 to drive the laser diode module 3, a storage unit 7 that stores a voltage setting value where the drive voltage is set according to the characteristics of the laser diode module 3, and an oscillator control unit 9 that controls the drive power supply to emit a laser from the laser diode module 3. The oscillator control unit 9 acquires the voltage setting value from the storage unit 7 and sets it for the drive power supply 5. The drive power supply 5 then applies the drive voltage to the laser diode module 3 according to the set voltage setting value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laser oscillator. [Background technology]

[0002] Generally, there is variation in the current-voltage characteristics of laser diodes, so when performing constant voltage control on laser diode modules, it is desirable to adjust the voltage for each laser diode module to reduce heat loss. For this reason, Patent Document 1 discloses a laser driver that monitors the operating voltage of a driver circuit that drives a laser light source and controls the output voltage from a voltage source. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-185997 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional laser driving device described above, in order to obtain the optimum operating voltage for the driving circuit, it was necessary to monitor the operating voltage and repeatedly perform feedback control. Therefore, in the conventional laser driving device, there was a problem in that a complex circuit configuration and calculation processing were required to reduce heat loss. [Means for solving the problem]

[0005] One or more aspects of the embodiment include a laser diode module that emits a laser, a drive power supply that applies a drive voltage to the laser diode module to drive the laser diode module, a memory unit that stores a voltage setting value for the drive voltage that is set in accordance with the characteristics of the laser diode module, and an oscillator control unit that controls the drive power supply to emit a laser from the laser diode module, wherein the oscillator control unit acquires the voltage setting value from the memory unit and sets it in the drive power supply, and the drive power supply is a laser oscillator that applies the drive voltage to the laser diode module in accordance with the set voltage setting value. [Effects of the Invention]

[0006] According to one or more embodiments of the laser oscillator, heat loss can be reduced without complex circuit configurations and computational processing. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a block diagram showing the configuration of a laser oscillator according to the first embodiment. [Figure 2] FIG. 2 is a diagram for explaining the effect of reducing heat loss by the laser oscillator according to the first embodiment. [Figure 3] FIG. 3 is a flowchart showing a processing procedure for setting a voltage setting value by the laser oscillator according to the first embodiment. [Figure 4] FIG. 4 is a block diagram showing the configuration of a laser oscillator according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] [First embodiment] Hereinafter, a laser oscillator according to this embodiment will be described with reference to the drawings. In the description of the drawings, the same parts are given the same reference numerals and detailed description will be omitted.

[0009] [Laser oscillator configuration] The configuration of a laser oscillator according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing the configuration of the laser oscillator according to the first embodiment. As shown in Fig. 1, the laser oscillator 1 includes a laser diode module 3 that emits laser light, a driving power supply 5 that applies a driving voltage, a storage unit 7 that stores a voltage setting value, and an oscillator control unit 9 that controls the driving power supply 5 to emit the laser light. The laser oscillator 1 also includes a pulse generation unit 11 that generates a pulse command.

[0010] The laser oscillator 1 outputs a laser beam emitted from the laser diode module 3. The output laser beam is transmitted to a laser processing machine via a process fiber and used to cut or weld a workpiece. The laser oscillator 1 is connected to a control device 13 such as an NC (Numerical Control) device, receives laser commands from the control device 13, adjusts the optical output according to the received laser commands, and outputs the laser beam.

[0011] The laser diode module 3 drives the laser diode with a drive voltage applied from a drive power supply 5 to emit a laser beam. The laser diode module 3 includes a storage section 7, a laser diode unit 21, and a current control section .

[0012] The laser diode unit 21 is composed of a plurality of laser diodes, and receives a drive voltage applied from a drive power supply 5 as a forward voltage, and the optical output is adjusted by constant current control of a current control section 23 .

[0013] The current control unit 23 controls the forward current flowing through the laser diode unit 21 in accordance with a pulse command from the pulse generating unit 11. The current control unit 23 includes a switching element 25 and an operational amplifier 27. The switching element 25 is configured, for example, by a MOSFET (field effect transistor). The gate voltage of the MOSFET is adjusted by the operational amplifier 27, thereby controlling the forward current flowing through the laser diode unit 21.

[0014] The memory unit 7 stores a voltage setting value that sets the drive voltage according to the characteristics of the laser diode module 3. Specifically, the voltage setting value is set to the smallest drive voltage value among the drive voltages that cause the laser diode module 3 to generate the maximum optical output, and is set by measuring the drive voltage when the maximum optical output is actually generated. The laser diode module 3 can generate the maximum optical output even when a drive voltage higher than necessary is applied, but the excess drive voltage causes heat loss in the switching element 25. Therefore, by setting the drive voltage value to the smallest drive voltage value among the drive voltages that cause the laser diode module 3 to generate the maximum optical output, it is possible to minimize the heat loss.

[0015] The storage unit 7 is provided in the laser diode module 3, and specifically, is a memory provided on the control board 29 of the laser diode module 3. However, the voltage setting value may be stored in the memory of the oscillator control unit 9, rather than on the control board 29 of the laser diode module 3. In other words, the storage unit 7 may be provided in the oscillator control unit 9.

[0016] The driving power supply 5 is a DC power supply that applies a driving voltage to the laser diode module 3 to drive the laser diode module 3, and in particular functions as a constant voltage control power supply that applies a constant voltage to the laser diode unit 21. Specifically, the driving power supply 5 applies the driving voltage to the laser diode module 3 in accordance with a voltage setting value set by the oscillator control unit 9.

[0017] The control device 13 is an NC device or the like for controlling the laser processing machine, stores processing programs and processing conditions, and outputs laser commands in accordance with this information. The laser commands include information such as laser output, duty, and frequency.

[0018] The pulse generating unit 11 receives a laser command from the control device 13 and outputs a pulse command in accordance with the laser command. The pulse command is output to an operational amplifier 27 of the current control unit 23, which adjusts the gate voltage of the switching element 25. In this way, the current control unit 23 controls the forward current of the laser diode unit 21.

[0019] The oscillator control unit 9 controls the driving power supply 5 to emit laser light from the laser diode module 3. In particular, the oscillator control unit 9 acquires a voltage setting value from the storage unit 7 and sets it in the driving power supply 5.

[0020] By setting the voltage setting value for the drive power supply 5 in this way, it is possible to reduce heat loss in the laser oscillator 1. Generally, the current-voltage characteristics of laser diode modules vary from one laser diode module to another. However, in the past, productivity was given priority and a common drive voltage was used for each laser diode module.

[0021] For example, as shown in Figure 2, when the forward current IF required to generate the maximum optical output is 100.00 [A], the forward voltage VF is set to a fixed value of X [V], and this X [V] is used as a common drive voltage for many laser diode modules. However, in reality, when the smallest drive voltage required to generate the maximum optical output and minimize heat loss in a laser diode module is measured, the forward voltage VF is X-2 [V], as shown in Figure 2. In other words, for this laser diode module, the optimal value of the forward voltage VF is X-2 [V].

[0022] Therefore, in the case of this laser diode module, if the forward voltage VF is changed from a fixed value of X [V] to an optimum value of X-2 [V], heat loss can be reduced by 200 [W]. Therefore, by measuring the optimum forward voltage for each laser diode module in advance and storing it in each laser diode module as a voltage setting value, it becomes possible to reduce heat loss in each laser diode module.

[0023] This heat loss is also consumed as thermal energy in the switching element 25 of the current control unit 23. Because the switching element 25 is a power semiconductor such as a MOSFET, reducing the heat loss can reduce the thermal load on the power semiconductor. This makes it possible to lower the failure rate of the power semiconductor and extend its lifespan. Furthermore, it also makes it possible to reduce the flow rate of the cooling water used to cool the power semiconductor.

[0024] The oscillator control unit 9 is configured by a computer having a memory, a processor such as a CPU (Central Processing Unit), and various interfaces. The memory and various interfaces are connected to the processor via a bus. The processor executes a program stored in the memory, causing the oscillator control unit 9 to perform a process of setting the voltage setting value in the driving power supply 5.

[0025] [Voltage setting process] Next, a description will be given of the process of setting the voltage setting value by the oscillator control unit 9 of the laser oscillator 1 according to this embodiment. Fig. 3 is a flowchart showing the procedure of the process of setting the voltage setting value.

[0026] As shown in FIG. 3, in step S10, the oscillator control unit 9 determines whether the power of the laser oscillator 1 is turned on, and if the power is turned on, proceeds to step S20, and if the power is not turned on, continues to determine whether the power is turned on.

[0027] In step S20, the oscillator control unit 9 acquires the number of laser diode modules 3 provided in the laser oscillator 1. The number of laser diode modules 3 is recorded in advance in a memory or a database, and the oscillator control unit 9 accesses the memory or the database to acquire the number of laser diode modules 3. In this embodiment, a case where there is one laser diode module 3 will be described, as shown in FIG.

[0028] In step S30, the oscillator control unit 9 accesses the storage unit 7 and reads and acquires the voltage setting value stored in the storage unit 7.

[0029] In step S40, the oscillator control unit 9 determines whether the voltage setting value acquired in step S30 is the same as the voltage setting value acquired the previous time the power was turned on, and if they are not the same, proceeds to step S50. On the other hand, if the voltage setting value acquired in step S30 is the same as the voltage setting value acquired the previous time the power was turned on, the voltage setting value setting process according to this embodiment ends.

[0030] In step S50, the oscillator control unit 9 writes and sets the voltage setting value acquired in step S30 in the driving power supply 5, thereby completing the voltage setting value setting process according to this embodiment. Note that while the voltage setting value is being read and written in steps S30 and S50, the output of the driving power supply 5 is interlocked for safety reasons.

[0031] Thereafter, the driving power supply 5 applies the driving voltage adjusted to the voltage setting value to the laser diode module 3, and the laser diode module 3 emits laser light with the applied driving voltage.

[0032] [Effects of the first embodiment] As described above in detail, the laser oscillator 1 according to this embodiment includes a memory unit 7 that stores a voltage setting value for the drive voltage, which is set in accordance with the characteristics of the laser diode module 3. The oscillator control unit 9 then acquires the voltage setting value from the memory unit 7 and sets it in the drive power supply 5, and the drive power supply 5 applies a drive voltage to the laser diode module 3 in accordance with the set voltage setting value. This allows the optimum drive voltage in accordance with the characteristics of the laser diode module 3 to be applied to the laser diode module 3, thereby reducing heat loss without requiring a complex circuit configuration or calculation processing.

[0033] Furthermore, the laser oscillator 1 according to this embodiment sets the voltage setting value to the smallest drive voltage value among the drive voltages that generate the maximum optical output from the laser diode module 3. This allows the drive voltage to be set to an optimal value without requiring complex circuit configurations and calculation processing, and also reduces heat loss.

[0034] Furthermore, in the laser oscillator 1 according to this embodiment, a storage unit 7 is provided in the laser diode module 3. This makes it possible to easily manage the voltage setting value for each laser diode module, even if the voltage setting value differs depending on the laser diode module.

[0035] [Second embodiment] Hereinafter, a laser oscillator according to the second embodiment will be described with reference to the drawings. In the drawings, the same parts are denoted by the same reference numerals, and detailed description thereof will be omitted. In the first embodiment, a case where there is one laser diode module 3 is described, but in the second embodiment, a case where there are multiple laser diode modules 3 is described.

[0036] [Laser oscillator configuration] The configuration of the laser oscillator according to this embodiment will be described with reference to Fig. 4. Fig. 4 is a block diagram showing the configuration of the laser oscillator according to this embodiment. As shown in Fig. 4, the laser oscillator 1 includes a plurality of laser diode modules 3A, 3B. However, the number of laser diode modules 3A, 3B may not be two, but may be three or more.

[0037] The configuration of the laser diode modules 3A, 3B is the same as that of the first embodiment, and memories 7A, 7B are provided for each of the plurality of laser diode modules 3A, 3B, and store the voltage setting values ​​of the provided laser diode modules 3A, 3B. The drive power supply 5 applies drive voltages to each of the plurality of laser diode modules 3A, 3B in accordance with their respective voltage setting values.

[0038] The voltage setting values ​​stored in the memory units 7A and 7B are set according to the characteristics of the laser diode modules 3A and 3B, so if the characteristics are different, they are set to different values, and if the characteristics are the same, they are set to the same value.

[0039] The configuration other than the laser diode modules 3A and 3B is also the same as that of the first embodiment, but the number of drive power sources 5 provided may be the same as that of the laser diode modules 3A and 3B.

[0040] [Voltage setting process] Next, a description will be given of the process of setting the voltage setting value by the oscillator control unit 9 of the laser oscillator 1 according to this embodiment. In this embodiment, the same process as that shown in the flowchart of Fig. 3 in the first embodiment is performed, so the process of setting the voltage setting value according to this embodiment will be described with reference to Fig. 3.

[0041] As shown in FIG. 3, in step S10, the oscillator control unit 9 determines whether the power of the laser oscillator 1 is turned on, and if the power is turned on, proceeds to step S20, and if the power is not turned on, continues to determine whether the power is turned on.

[0042] In step S20, the oscillator control unit 9 acquires the number of laser diode modules 3A, 3B provided in the laser oscillator 1. In this embodiment, as shown in FIG. 4, there are two laser diode modules 3A, 3B, so the oscillator control unit 9 acquires "2."

[0043] In step S30, the oscillator control unit 9 accesses the storage units 7A and 7B of the laser diode modules 3A and 3B, respectively, and reads and acquires the voltage setting values ​​stored in the storage units 7A and 7B, respectively.

[0044] In step S40, the oscillator control unit 9 determines whether the voltage setting values ​​acquired in step S30 are the same as the voltage setting values ​​acquired the previous time the power was turned on. At this time, the oscillator control unit 9 determines whether the voltage setting values ​​of the laser diode modules 3A and 3B are the same as the voltage setting values ​​acquired the previous time the power was turned on. If the voltage setting values ​​acquired in step S30 are not the same as the voltage setting values ​​acquired the previous time the power was turned on, the process proceeds to step S50; if they are the same, the voltage setting value setting process according to this embodiment ends.

[0045] In step S50, the oscillator control unit 9 writes and sets the voltage setting value acquired in step S30 in the driving power supply 5. At this time, the oscillator control unit 9 writes and sets the voltage setting values ​​of the laser diode modules 3A and 3B in the driving power supply 5. When the voltage setting values ​​of the laser diode modules 3A and 3B are written in the driving power supply 5 in this manner, the voltage setting value setting process according to this embodiment is completed.

[0046] Thereafter, the drive power supply 5 applies a drive voltage to each of the laser diode modules 3A and 3B that has been adjusted to the respective voltage setting values, and the laser diode modules 3A and 3B emit laser light at the drive voltages applied to them.

[0047] [Effects of the second embodiment] As described above in detail, the laser oscillator 1 according to this embodiment includes multiple laser diode modules 3A, 3B. Memory units 7A, 7B are provided for each of the multiple laser diode modules 3A, 3B, and store the voltage setting values ​​for the laser diode modules 3A, 3B. The drive power supply 5 applies drive voltages to each of the multiple laser diode modules 3A, 3B in accordance with their respective voltage setting values. This allows the application of optimal drive voltages according to the characteristics of each laser diode module 3A, 3B, even when multiple laser diode modules 3A, 3B are provided, thereby reducing heat loss without requiring complex circuit configurations and calculation processes.

[0048] Although the embodiments of the present invention have been described above, the descriptions and drawings that form part of this disclosure should not be understood to limit the present invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure. [Explanation of symbols]

[0049] 1 Laser oscillator 3, 3A, 3B Laser Diode Module 5. Drive power supply 7, 7A, 7B storage section 9 Oscillator control section 11 Pulse generation unit 13 Control device 21, 21A, 21B Laser diode unit 23, 23A, 23B Current control section 25, 25A, 25B switching elements 27, 27A, 27B Op-Amps 29, 29A, 29B control board

Claims

1. a laser diode module that emits a laser; a driving power supply that applies a driving voltage to the laser diode module; a storage unit that stores a voltage setting value that sets the drive voltage in accordance with the characteristics of the laser diode module; an oscillator control unit that controls the drive power supply to cause the laser diode module to emit a laser beam, the oscillator control unit acquires the voltage setting value from the storage unit and sets it in the drive power supply; The driving power supply applies the driving voltage to the laser diode module in accordance with the set voltage setting value. Laser oscillator.

2. The voltage setting value is set to the smallest driving voltage value among the driving voltages at which the laser diode module generates the maximum optical output.

2. The laser oscillator according to claim 1.

3. The storage unit is provided in the laser diode module.

2. The laser oscillator according to claim 1.

4. a plurality of the laser diode modules; the storage unit is provided for each of the plurality of laser diode modules, and stores the voltage setting value of the provided laser diode module; The driving power supply applies the driving voltage to each of the plurality of laser diode modules in accordance with the voltage setting value.

4. The laser oscillator according to claim 1.

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