JP2009226445A - Scanning type laser beam machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the high speed performance and reproducibility of multipoint simultaneous machining in a scanning type laser beam machining apparatus. <P>SOLUTION: A plurality of galvano control parts 22(1), 22(2), ..., used for a plurality of galvanometer scanners 14(1), 14(2), ..., respectively are connected in parallel to the main control part 20. Each galvano control part 22(n) is provided with a field programmable gate array (FPGA) 50(n) of one chip, digital-analog conversion circuits (DAC) 60(n), 62(n) for X axis and Y axis, and galvano driving circuits 64(n), 66(n) for X axis and Y axis. In the FPGA 50(n), an FIFO 52(n), a correcting register 54(n), a computing circuit 56(n), and an output control circuit 58(n) are configured. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a scanning laser processing apparatus in which a plurality of galvanometer scanners are optically connected in parallel to a single laser oscillator, and the same pattern is formed simultaneously on different workpieces or processing regions.

  In scanning laser processing, the laser beam is scanned (scanned) to move the laser beam spot two-dimensionally on the surface of the workpiece, and a small portion of the workpiece surface hit by the beam spot is subjected to laser energy. In this technique, a desired pattern of characters, figures, symbols, etc. is formed on a workpiece by instantaneous evaporation or discoloration, and marking or other surface processing is performed.

  In general, a scanning laser processing apparatus includes a laser oscillator that oscillates and outputs laser light, a galvanometer scanner that focuses and irradiates a workpiece while scanning the laser light output from the laser oscillator, a laser oscillator, and And a control unit that controls each operation (laser oscillation operation, scanning operation) of the galvanometer scanner.

  The galvanometer scanner is also called a scanning head or the like, and has an X-axis rotating mirror and a Y-axis rotating mirror for two-dimensionally scanning laser light, and a coordinate position command signal corresponding to a desired scanning position from the control unit. Alternatively, each rotating mirror is driven to rotate (swing) by using, for example, a servo motor in response to a mirror deflection angle command signal.

  2. Description of the Related Art Conventionally, a scanning laser processing apparatus that can perform multi-point simultaneous processing is known (see, for example, FIG. 6 of Patent Document 1). The scanning laser processing device of the multi-point simultaneous processing type connected to a plurality of galvanometer scanners via a laser branching unit and a transmission optical fiber etc. to one laser oscillator, and oscillated and output from the laser oscillator A single laser beam is divided into a plurality of branched laser beams, and the plurality of branched laser beams are irradiated to different processing positions while being scanned by the corresponding galvanometer scanners. The desired pattern is formed simultaneously on different workpieces or regions.

In the conventional scanning laser processing equipment, the control system for controlling the laser oscillation operation and the scanning operation is composed of a CPU (central processing unit) and peripheral circuits (mainly drive circuits), and all calculations necessary for control are performed. Even in the multi-point simultaneous machining type as described above, the point was not changed.
JP2007-190560

  However, in the case of the multi-point simultaneous machining type, since a plurality of galvanometer scanners are operated in parallel at the same time, the computation required for the scanning operation is enormous. In this type of conventional scanning laser processing apparatus, the CPU (software) is It was not able to cope with it.

  In other words, the galvanometer scanner has various optical distortions or errors not only in the X-axis rotating mirror and Y-axis rotating mirror but also in the scanner mounting section, fθ lens, etc., and these settings are not corrected by the user. When scanning is performed based on the coordinate position of the input pattern, the marking pattern is distorted and formed on the workpiece. For example, a pattern that is supposed to be rectangular is marked as a barrel pattern. Therefore, various correction parameters for compensating for optical distortion in such a galvanometer scanner are prepared in advance, and sequentially read out from a memory storing pattern information set by the user during a scanning operation. An operation for correcting each scanning position or coordinate position with a correction parameter is required. This correction calculation is mainly multiplication and addition / subtraction, but the calculation formula and the number of calculations are very large, and if the CPU executes a number of calculation instructions many times while repeating a number of machine cycles, only one galvanometer scanner is required. But it takes a lot of computation time.

  In the case of a multi-point simultaneous machining type, this problem becomes more serious. That is, when a plurality of galvanometer scanners are used, there are variations in optical distortion between scanners and machine differences, and in order to increase the processing accuracy, an independent correction calculation is required for each galvanometer scanner.

  This type of conventional laser processing apparatus has a limitation in the processing speed of the CPU (software) as described above, so this function is not sufficient, and the processing speed is higher than that of a one-point processing type apparatus. The reproducibility of the machining quality is not possible because it is not possible to perform high-precision correction calculations that require a significant amount of calculations or result in significant degradation (as a result, the optical distortion of the galvanometer scanner cannot be fully compensated). There were problems such as bad.

  The present invention solves the above-described problems of the prior art, and an object of the present invention is to provide a scanning laser processing apparatus that improves the high speed and reproducibility of multi-point simultaneous processing.

  In order to achieve the above object, the scanning laser processing apparatus of the present invention optically connects N galvanometer scanners (N is an integer of 2 or more) to one laser oscillator. The laser beam that has been oscillated and output is divided into N branch laser beams, and these branch laser beams are irradiated to a desired scanning position while being scanned by the corresponding galvanometer scanner, and a desired pattern is applied to a plurality of laser beams. A scanning-type laser processing apparatus for simultaneously forming a workpiece or a processing region, wherein the laser oscillation operation of the laser oscillator and the scanning operation of each of the N galvanometer scanners are collectively controlled. The scanning operation of the N galvanometer scanners is locally controlled under the overall control of the main control unit and the main control unit. That includes an N-number of the scanner control unit. Each of the scanner control units stores a first data storage unit for storing position data given by the main control unit to instruct the galvanometer scanner for the scanning position, and the galvanometer scanner. Read out from the first data storage unit and the second data storage unit, the second data storage unit storing the correction parameter data given from the main control unit to correct the optical distortion of Based on the position data and the correction parameter data, a calculation unit that calculates a correction position specific to the galvanometer scanner corresponding to the scanning position by calculation, and based on the correction position data obtained by the calculation unit The galvanometer that rotationally drives the rotating mirror of the galvanometer scanner to the deflection angle corresponding to the scanning position. And a dynamic part.

  In the above apparatus configuration, a plurality of galvanometer scanners are each provided with a scanner control unit, and each scanner control unit locally or directly controls the galvanometer scanner under the overall control of the main control unit. Each scanner control unit includes a first data storage unit specialized for storing or storing data of a scanning position given from the main control unit to the galvanometer scanner, and an optical distortion of the galvanometer scanner. A correction data specific to the galvanometer scanner corresponding to the scanning position, and a second data storage unit specialized for storing correction parameter data given by the main control unit for correcting The rotation mirror of the galvanometer scanner can be rotationally driven to the deflection angle corresponding to the scanning position in a short time while adequately compensating for the optical distortion of the galvanometer scanner. . As the entire system, multiple scanner control units execute arithmetic processing simultaneously or in parallel, and control the scanning operations of multiple galvanometer scanners, respectively. Productivity is improved.

  In a preferred aspect of the present invention, the main control unit includes a central processing unit, and the central processing unit directly transmits the scanning position data and the correction parameter data to the first data storage unit and the second data storage unit, respectively. Write. The first data storage unit is preferably a first-in first-out memory, so-called FIFO (First-In First-Out) memory, and the second data storage unit is preferably a register. A digital signal processing circuit can be suitably used for the arithmetic unit.

  In a preferred embodiment, the first data storage unit, the second data storage unit, and the arithmetic circuit are constructed in a one-chip field programmable gate array (FPGA). More preferably, each scanner control unit further includes an output control unit for supplying the correction position data obtained by the calculation unit to the galvano drive unit at a predetermined timing, and the first data storage unit, Two data storage units, a calculation unit and an output control unit are built in a one-chip field programmable gate array. By using a field programmable gate array in this way, circuit design can be rationalized and costs can be reduced.

  In a preferred aspect, the galvano drive unit converts a digital correction position signal output as correction position data from the calculation unit into an analog correction position signal, and an analog correction position signal. And a galvanometer drive circuit for generating a mirror drive current for rotationally driving the rotary mirror of the galvanometer scanner.

  In a preferred embodiment, when the galvanometer scanner has an fθ lens, the origin of the fθ lens relative to the origin of the galvanometer scanner (that is, the coordinate point when the scanner is installed (mirror deflection angle is 0 degree)) Correction parameters for correcting the offset (that is, positional error) of the center of the lens are set, or correction parameters for correcting barrel distortion due to the influence of optical components such as the fθ lens and the rotating mirror of the scanner are set. Is done. In addition, a correction parameter for correcting an attachment error of the galvanometer scanner and a correction parameter for correcting a driving gain of the galvanometer scanner are set.

  In a preferred aspect, the rotating mirror in each galvanometer scanner includes an X-axis rotating mirror and a Y-axis rotating mirror for scanning the laser light in directions orthogonal to each other. In this case, X-axis coordinate position data and Y-axis coordinate position data are given to the galvanometer scanner from the main control unit as desired scanning positions.

  Further, the laser oscillator is preferably a Q-switch type, and an optical resonator composed of a pair of mirrors disposed optically opposite to each other, an active medium disposed on an optical path in the optical resonator, and the active medium An active medium excitation unit that continuously excites, a Q switch disposed on the same optical path as the active medium in the optical resonator, and a Q switch drive unit that drives the Q switch under the control of the main control unit Have. In this case, the laser oscillator preferably has an optical fiber, and the core of the optical fiber may be used as the active medium. The active medium excitation unit preferably includes a laser diode that outputs excitation light in a continuous oscillation and an optical lens that optically couples the laser diode to an optical fiber.

  According to the scanning type laser processing apparatus of the present invention, the high speed and reproducibility of multi-point simultaneous processing can be improved by the configuration and operation as described above.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows the configuration of a scanning laser processing apparatus according to an embodiment of the present invention. This laser machining apparatus uses three simultaneous workpieces W on three machining tables 10 (1), 10 (2), 10 (3) using a simultaneous multi-branch, for example, simultaneous three-branch fiber transmission system. (1), W (2), W (3) adopts the same or the same type of scanning laser processing, for example, a multi-point simultaneous processing type system form in which laser marking is applied.

  This laser processing apparatus has, as a laser optical system, one Q-switch type fiber laser oscillator 12 that oscillates and outputs a laser beam LB of a Q switch pulse, and each processing table 10 (1), 10 (2), 10 (3 ) 3 scanning heads or galvanometer scanners 14 (1), 14 (2), 14 (3) disposed above the 3) and one original laser beam LB oscillated and output from the fiber laser oscillator 12. The laser branching section 16 that splits the branched laser beams LB (1), LB (2), and LB (3), and the branched laser beams LB (1), LB (2), LB from the laser branching section 16 Three optical fibers 18 (1), 18 (2), and 18 (3) for transmitting (3) to the galvanometer scanners 14 (1), 14 (2), and 14 (3), respectively, are provided.

  In addition, this laser processing apparatus has a single main control unit 20 that performs overall control of operations of each unit in the system as a control system, and a galvanometer scanner 14 (1), under the overall control of the main control unit 20. Three scanner control units 22 (1), 22 (2), and 22 (3) for locally or directly controlling the scanning operations 14 (2) and 14 (3), respectively. Further, a laser power source 24 that supplies pumping power to the fiber laser oscillator 12 under the control of the main control unit 20 is provided.

  The fiber laser oscillator 12 includes an oscillation optical fiber (hereinafter referred to as “oscillation fiber”) 26, an electro-optic excitation unit 28 that irradiates one end surface of the oscillation fiber 26 with pumping excitation light EB, and an oscillation fiber. And a pair of optical resonator mirrors 30 and 32 which are optically opposed to each other via the H.26.

  The electro-optical excitation unit 28 includes a laser diode (LD) 34 and a condensing optical lens 36. The LD 34 is driven to emit light by an excitation current from the laser power source 24, and outputs laser light for excitation or LD light EB by continuous oscillation. The optical lens 36 condenses and enters the excitation LD light EB from the LD 34 onto one end face of the oscillation fiber 26. The optical resonator mirror 30 disposed between the LD 34 and the optical lens 36 transmits the excitation LD light EB incident from the LD 34 side, and transmits the oscillation light beam incident from the oscillation fiber 26 side on the optical axis of the optical resonator. It is configured to totally reflect.

  Although not shown, the oscillation fiber 26 has a core doped with, for example, rare earth ions as a light emitting element, and a clad surrounding the core coaxially. The core is used as an active medium, and the clad is used as a propagation of excitation light. The light path. The excitation LD light EB incident on one end face of the oscillation fiber 26 as described above propagates in the oscillation fiber 26 in the axial direction while being confined by total reflection at the outer peripheral interface of the clad, and the core passes during the propagation. The rare earth element ions in the core are photoexcited by crossing the core. In this way, an oscillating light beam having a predetermined wavelength is emitted in the axial direction from both end faces of the core, and this oscillating light beam travels between the optical resonator mirrors 30 and 32 many times and is resonantly amplified.

  On the optical path between the optical resonator mirrors 30 and 32, for example, a Q switch 40 composed of an acousto-optic switch is disposed. The Q switch driver 42 drives the Q switch 40 by a high frequency electrical signal that is temporarily interrupted at a predetermined cycle under the control of the main control unit 20. By this Q switching, every time the high-frequency electrical signal is interrupted, the laser light LB of the Q switch pulse or the giant pulse having an extremely high peak power is oscillated and output from the fiber laser oscillator 12.

  In the fiber laser oscillator 12, the optical lenses 36 and 38 collimate the oscillation light beam emitted from the end face of the oscillation fiber 26 into parallel light and pass it to the optical resonator mirrors 30 and 32, and the optical resonator mirrors 30 and 32. The oscillating light beam reflected and returned by is condensed on the end face of the oscillating fiber 26.

  The laser branching unit 16 in the illustrated configuration example is a simultaneous three-branching type, and includes three branching mirrors 44 (1), 44 (2), and a predetermined interval on the extension of the optical axis of the fiber laser oscillator 12. 44 (3) are inclined at a predetermined angle (for example, 45 degrees) and arranged in a line. Of these, the first-stage and next-stage branching mirrors 44 (1), 44 (2) are made of partially reflecting / transmitting mirrors or beam splitters, and the last-stage mirror 44 (3) is made of a totally reflecting mirror. For example, when the power split ratio of the simultaneous three branches is set to 1: 1: 1, the branch ratio of the first stage beam splitter 44 (1) is selected to be about 33/67, and the branch ratio of the next stage beam splitter 44 (2) is selected. About 50/50 is selected.

  In this laser branching section 16, the fiber laser beam LB propagating straight from the fiber laser oscillator 12 into the air first enters the first stage beam splitter 44 (1), where a part thereof is reflected in a predetermined direction and the rest is straight. To Penetrate. The reflected light obtained by the beam splitter 44 (1), that is, the first branched laser light LA (1) is transmitted through the first incident unit 46 (1) to the first transmission optical fiber (hereinafter referred to as “transmission fiber”). It is incident on one end face of 18 (1).

  The laser beam LB ′ that has passed through the first stage beam splitter 44 (1) is incident on the next stage beam splitter 44 (2), where a part of the laser light LB ′ is reflected in a predetermined direction and the rest is transmitted straight. The reflected light obtained by the beam splitter 44 (2), that is, the second branched laser beam LB (2) is incident on one end face of the second transmission fiber 18 (2) through the second incident unit 46 (2). To do.

  The laser beam LB "that has passed through the next-stage beam splitter 44 (2) is totally reflected in a predetermined direction by the terminal total reflection mirror, and is converted into a third incident unit 46 (3) as a third branched laser beam LB (3). Then, the light enters the one end face of the third transmission fiber 18 (3).

  In each incident unit 46 (1), 46 (2), 46 (3), each branched laser beam LB (1), LB (2), LB (3) is transmitted to each transmission fiber 18 (1), 18 ( 2) and condensing lenses 48 (1), 48 (2) and 48 (3) for condensing light are provided on one end face of 18 (3). For example, SI (step index) type fibers are used for the transmission fibers 18 (1), 18 (2), and 18 (3).

  The other ends or terminations of the first, second and third transmission fibers 18 (1), 18 (2), 18 (3) are connected to the first, second and third galvanometer scanners 14 (1), 14 They are connected to (2) and 14 (3), respectively.

  Each galvanometer scanner 14 (n) (where n = 1, 2, 3, the same notation is used for other components below), although not shown, a collimator lens and an X-axis rotating mirror are provided in the unit housing. The Y-axis rotating mirror and the fθ lens are optically arranged at predetermined positions in this order. The collimating lens collimates the laser beam LB (n) emitted radially from the end face of each corresponding transmission fiber 18 (n) into parallel light. The X-axis rotating mirror is rotationally driven at a deflection angle corresponding to the scanning position, and directs the parallel laser beam LB (n) from the collimating lens toward the target position on the workpiece W (n) in the X-axis direction. reflect. The Y-axis rotating mirror is also rotationally driven at a deflection angle corresponding to the scanning position, and reflects the laser beam LB (n) from the X-axis rotating mirror toward the target position on the workpiece W (n) in the Y-axis direction. To do. The rotation (swinging) operation of the X-axis rotating mirror and the Y-axis rotating mirror is directly controlled by the galvano controller 22 (n) under the overall control of the main controller 20, as will be described in detail later. The The fθ lens has an effect of making the scanning speed constant with respect to an arbitrary scanning position (fθ characteristic), and the laser beam LB (n) from the Y-axis rotating mirror is used as a target position on the workpiece W (n). Condensed to

  In the illustrated example, the workpieces W (1), W (2), and W (3) on the machining tables 10 (1), 10 (2), and 10 (3) are first, second, and third. The first, second and third branched laser beams LB (1), LB (2) and LB (3) are simultaneously condensed and irradiated from the galvanometer scanners 14 (1), 14 (2) and 14 (3). The same marking pattern is simultaneously formed on the workpieces W (1), W (2), and W (3).

  FIG. 2 shows the configuration of the control system in this embodiment, particularly the circuit configuration of each galvano controller 22 (n). The galvano control units 22 (1), 22 (2), and 22 (3) have the same configuration in terms of hardware. Therefore, in FIG. 2, only the first and second galvano control units 22 (1) and 22 (2) are shown to simplify the illustration, and the third galvano control unit 22 (3) is omitted. is doing.

  As shown in FIG. 2, the galvano control units 22 (1), 22 (2),... Are connected to the main control unit 20 in parallel. Each galvano controller 22 (n) includes one (one chip) field programmable gate array (FPGA) 50 (n) and a pair of digital-analog conversion circuits (DAC) 60 for the X and Y axes. n), 62 (n) and a pair of galvano drive circuits 64 (n), 66 (n) for the X-axis and Y-axis. In the FPGA 50 (n), FIFO 52 (n), correction register 54 (n), arithmetic circuit 56 (n) and output control circuit 58 (n) are provided as functional blocks programmed on hardware (wiring design). Equipped with or built.

  The main control unit 20 includes a CPU (central processing unit), and executes data transfer commands, input / output commands, and the like, and directly provides data or control signals to each functional block in the FPGA 50 (n). FIG. 3 shows an example of a memory map and an I / O map (memory mapped I / O method) in this embodiment.

More specifically, the FIFO 52 (n) has a desired common to all galvanometer scanners 14 (1), 14 (1), 14 (3) from the CPU of the main controller 20 during execution of laser marking. X-axis coordinate and Y-coordinate data (X _in , Y _in ) are written in a first- _in first-out manner as scanning position coordinates.

  In the correction register 54 (n), various correction parameters for compensating optical distortion inherent in the galvanometer scanner 14 (n) from the CPU of the main control unit 20 before execution of laser marking or at the time of initialization. Data is written. In this embodiment, the following correction parameters (A) to (D) are set.

(A) XY axis offset correction parameters (X _ofs , Y _ofs )
For correcting the offset (deviation) between the origin of the fθ lens and the origin of the galvanometer scanner in the galvanometer scanner 14 (n), X _ofs is a constant parameter for the X axis coordinate, and Y _ofs is the Y axis coordinate. Is a constant parameter for

(B) XY axis crossing angle correction parameter (Ang)
This is a coefficient parameter for correcting the mounting error of the galvanometer scanner 14 (n).

(C) XY axis gain adjustment parameters (X _gain , Y _gain )
This is for adjusting the gain of each axis of the galvanometer scanner 14 (n). X _gain is a coefficient parameter for X axis, and Y _gain is a coefficient parameter for Y axis.

(D) fθ lens distortion correction parameter (X _dis , Y _dis )
For correcting barrel distortion of the fθ lens in the galvanometer scanner 14 (n), X _dis is an X axis distortion correction coefficient parameter, and Y _dis is a Y axis distortion correction coefficient parameter.

  It should be noted that the value of any one of the correction parameters (A) to (D) is made the same among some or all of the galvanometer scanners 14 (1), 14 (2), and 14 (3). It is also possible.

The arithmetic circuit 56 (n) receives a command from the CPU of the main control unit 20 during execution of laser marking and executes a required arithmetic process. That is, based on the coordinate position data (X _in , Y _in ) sequentially read out from the FIFO 52 (n) and the correction parameter data stored in the correction register 54 (i), the galvanometer corresponding to each scanning position. A correction coordinate position (X _out , Y _out ) specific to the scanner is obtained by calculation. In this embodiment, the following arithmetic expression is calculated as an example.

X ₁ = X _in + X _ofs (1) Y ₁ = Y _in + Y _ofs (2)
X ₂ = X ₁ + Ang × Y ₁ (3) Y ₂ = Y ₁ (4)
X ₃ = X ₂ × X _gain (5) Y ₃ = Y ₂ × Y _gain (6)
X _out = X ₃ + X _dis × Y ₃ × Y ₃ × X ₃ × 2 ⁻⁴⁸ (7)
Y _out = Y ₃ + Y _dis × X ₃ × X ₃ × Y ₃ × 2 ^-48 (8)

  FIG. 4 shows a circuit configuration of the arithmetic circuit 56 (n) for calculating the above arithmetic expression. In FIG. 4, the adder 100 calculates the above equation (1). The adder 102 calculates the above equation (2). The multiplier 104 and the adder 106 calculate the above equation (3). The multiplier 108 calculates the above equation (5). The multiplier 110 calculates the above equation (6). The multipliers 112 to 118 and the adder 120 calculate the above equation (7). The multipliers 122 to 128 and the adder 130 calculate the above equation (8).

  The adders and multipliers (100 to 130) in the arithmetic circuit 56 (n) can all be constituted by hardware adder circuits and multiplier circuits, but a digital signal processor (DSP) is also possible. Can also be realized. As described above, the types of calculations executed by the calculation circuit 56 (n) are only addition and multiplication, but the number of calculations is enormous. Therefore, a dedicated hardware circuit or DSP is suitable for speeding up this type of computation, and scanning position correction computation processing that is much faster than a CPU can be realized.

  Moreover, in this embodiment, the galvano control units 22 (1), 22 (2), and 22 (3) in the galvanometer scanners 14 (1), 14 (2), and 14 (3) respectively are used. Since the arithmetic circuits 56 (1), 56 (2), 56 (3) perform arithmetic processing simultaneously or in parallel, the number of galvanometer scanners 14 (1), 14 (2), 14 (3) Regardless of (however), it is possible to perform the correction calculation necessary to adequately compensate for the optical distortion of each scanner at a high speed (short time) with a sufficient margin.

When the coordinate position data (X _in , Y _in ) stored in the FIFO 52 (n) is less than a certain reference amount, the FIFO 52 (n) sends “free” to the CPU of the main control unit 20 at that time. In response to this, an interrupt signal informing the state is sent, and the subsequent coordinate position data (X _in , Y _in ) is newly written from the CPU to the FIFO 52 (n) in units of blocks.

The data of the corrected coordinate position (X _out , Y _out ) obtained as a calculation result from the calculation circuit 56 (n) as described above is sent to the output control circuit 58 (n). The output control circuit 58 (n) has a buffer for temporarily storing the data of the correction coordinate position (X _out , Y _out ), and corrects the X axis according to a control signal given from the CPU of the main control unit 20. both DAC 60 (n) at the timing of a constant period the data on the coordinate position X _out and Y-axis corrected coordinate position Y _out, and outputs the distributed respectively 62 (n).

DAC 60 (n) converts the data inputted as a digital signal X axis correction coordinates X _out the X-axis correction coordinate analog position signal. On the other hand, DAC 62 (n) converts the data inputted as a digital signal Y axis correction coordinate position Y _out into analog Y-axis correction coordinate position signal.

  The X-axis galvano drive circuit 64 (n) receives an X-axis correction coordinate position signal from the DAC 60 (n) and outputs an X-axis mirror drive current corresponding to the input signal. On the other hand, the Y-axis galvano drive circuit 66 (n) receives the Y-axis correction coordinate position signal from the DAC 62 (n) and outputs a Y-axis mirror drive current corresponding to the input signal.

  The galvanometer scanner 14 (n) includes an electromechanical mirror rotation drive mechanism (for example, a drive coil, a rotor, etc.) not shown, and includes an X-axis rotation mirror 68 (n) and a Y-axis rotation mirror 70 (n). Are rotationally driven (swinged) to swing angles in the X-axis direction and Y-axis direction corresponding to the X-axis mirror drive current and the Y-axis mirror drive current, respectively.

During the execution of the laser marking, the main control unit 20 sends the FIFOs 52 (1), 52 (2), 52 (3) to the galvano control units 22 (1), 22 (2), 22 (3). X-axis coordinate and Y-axis coordinate data (X _in , Y _in ) are given in block units _in response to an interrupt from the CPU, and the respective arithmetic circuits 56 (1), 56 (2), 56 (3) and output control Since it is only necessary to supply the necessary control signals to the circuits 58 (1), 58 (2), 58 (3), control other than the scanning operation, that is, control of the laser power source 24, the laser oscillator 12, etc., and an external device (not shown) It is possible to spend a sufficient amount of time for exchanging information with the device, and the performance of the entire apparatus can be improved.

  As described above, a high-speed parallel scanning operation can be performed while adequately compensating for the optical distortion for each of the plurality of galvanometer scanners 14 (1), 14 (2), 14 (3). High speed and reproducibility can be greatly improved.

  As mentioned above, although preferred embodiment of this invention was described, embodiment mentioned above does not limit this invention. Those skilled in the art can make various modifications and changes in specific embodiments without departing from the technical idea and technical scope of the present invention.

  For example, a YAG rod can be used instead of the core of the oscillation fiber 26 as an active medium in a Q-switch type laser oscillator. Further, the correction parameters used in the above-described embodiment and the calculation formulas (1) to (8) for correction are examples, and other correction parameters or calculation formulas can also be used, depending on the calculation formula used. The circuit configuration of the arithmetic circuit 56 (n) may be modified. In addition, the circuit configuration in the FPGA 50 (n) in the above embodiment can be modified in various ways.

It is a figure which shows the structure of the scanning type laser processing apparatus in one Embodiment of this invention. It is a figure which shows the circuit structure of the scanner control part in embodiment. It is a figure which shows the memory map and I / O map in embodiment. FIG. 3 is a circuit diagram illustrating a circuit configuration example of an arithmetic circuit included in a scanner control unit in the embodiment.

Explanation of symbols

12 Fiber laser oscillator 14 (1), 14 (2), 14 (3) Galvanometer scanner 16 Laser branching unit 18 (1), 18 (2), 18 (3) Optical fiber for transmission (transmission fiber)
20 Main Control Unit 22 (1), 22 (2), 22 (3) Scanner Control Unit 24 Laser Power Supply 30, 32 Optical Resonator Mirror 34 Excitation Laser Diode (LD)
40 Q switch 42 Q switch driver 50 (1), 50 (2) FPGA (field programmable gate array)
52 (1), 52 (2) FIFO (first-in first-out memory)
54 (1), 54 (2) Correction register 56 (1), 56 (2) Arithmetic circuit 58 (1), 58 (2) Output control circuit 60 (1), 62 (1), digital-analog conversion circuit ( DAC)
60 (2), 62 (2) Digital-analog conversion circuit (DAC)
64 (1), 66 (1), X-axis galvano drive circuit 60 (2), 62 (2) Y-axis galvano drive circuit 68 (1), 70 (1) X-axis rotating mirror 68 (2), 70 (2 ) Y-axis rotating mirror

Claims (15)

N galvanometer scanners are optically connected to one laser oscillator, and the laser beam oscillated and output from the laser oscillator is divided into N branch laser beams. A scanning laser processing apparatus that simultaneously forms a desired pattern on a plurality of workpieces or processing regions by irradiating a desired scanning position while scanning each of the branched laser beams with the corresponding galvanometer scanner. ,
A single main control unit for comprehensively controlling the laser oscillation operation of the laser oscillator and the scanning operations of the N galvanometer scanners;
And N scanner control units for locally controlling the scanning operations of the N galvanometer scanners under overall control of the main control unit,
Each of the scanner control units
A first data storage unit for storing position data given by the main control unit for instructing the scanning position to the galvanometer scanner;
A second data storage unit for storing correction parameter data given by the main control unit in order to correct optical distortion of the galvanometer scanner;
A calculation for calculating a correction position specific to the galvanometer scanner corresponding to the scanning position by calculation based on the position data and the correction parameter data read from the first data storage unit and the second data storage unit And
A scanning laser processing apparatus comprising: a galvano driving unit that rotationally drives a rotating mirror of the galvanometer scanner to a deflection angle corresponding to the scanning position based on the correction position data obtained by the arithmetic unit. The main control unit includes a central processing unit,
The scanning laser processing apparatus according to claim 1, wherein the central processing unit directly writes the position data and the correction parameter data in the first data storage unit and the second data storage unit, respectively.   The scanning laser processing apparatus according to claim 1, wherein the first data storage unit is a first-in first-out memory.   The scanning laser processing apparatus according to claim 1, wherein the second data storage unit includes a register.   The scanning laser processing apparatus according to claim 1, wherein the calculation unit includes a digital signal processing circuit.   The scanning laser processing according to any one of claims 1 to 5, wherein the first data storage unit, the second data storage unit, and the arithmetic unit are built in a one-chip field programmable gate array. apparatus. Each of the scanner control units further includes an output control unit for supplying the correction position data obtained by the calculation unit to the galvano drive unit at a predetermined timing,
The said 1st data storage part, the said 2nd data storage part, the said calculating part, and the said output control part are constructed | assembled in the field programmable gate array of 1 chip | tip. Scanning laser processing equipment. The galvo drive unit is
A digital-analog converter for converting a digital correction position signal output as the correction position data from the arithmetic unit into an analog correction position signal;
A scanning laser according to claim 5, further comprising: a galvano drive circuit that generates a mirror drive current for rotationally driving a rotary mirror of the galvanometer scanner based on the analog correction position signal. Processing equipment. The galvanometer scanner has an fθ lens;
The scanning laser processing apparatus according to claim 1, wherein the correction parameter includes a parameter for correcting an offset of an origin of the fθ lens with respect to an origin of the galvanometer scanner. The galvanometer scanner has an fθ lens;
The scanning laser processing apparatus according to claim 1, wherein the correction parameter includes a parameter for correcting barrel distortion of the fθ lens.   The scanning laser processing apparatus according to claim 1, wherein the correction parameter includes a parameter for correcting an attachment error of the galvanometer scanner.   The scanning laser processing apparatus according to claim 1, wherein the correction parameter includes a parameter for correcting a gain in driving the galvanometer scanner. The rotating mirror in each of the galvanometer scanners includes an X-axis rotating mirror and a Y-axis rotating mirror for scanning the laser light in directions orthogonal to each other;
The scanning type according to claim 1, wherein data of an X-axis coordinate position and a Y-axis coordinate position corresponding to the desired scanning position is given from the main control unit to the galvanometer scanner. Laser processing equipment. The laser oscillator is
An optical resonator composed of a pair of mirrors arranged optically opposite to each other;
An active medium disposed on an optical path in the optical resonator;
An active medium excitation unit for continuously exciting the active medium;
A Q switch disposed on the same optical path as the active medium in the optical resonator;
The scanning laser processing apparatus according to claim 1, further comprising: a Q switch driving unit that drives the Q switch under the control of the main control unit. The laser oscillator has an optical fiber;
The active medium is a core of the optical fiber;
The scanning laser processing apparatus according to claim 14, wherein the active medium excitation unit includes a laser diode that outputs excitation light by continuous oscillation, and an optical lens that optically couples the laser diode to the optical fiber.

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