JP2012030251A - Laser beam machining device - Google Patents

Abstract

A laser processing apparatus capable of easily improving the correction accuracy of the irradiation position of a visible light laser without having a data table.
A laser processing apparatus for processing a workpiece by converging a processing laser with an fθ lens and irradiating the workpiece with a guide laser for emitting a guide laser. A laser light source 14, a beam combiner 16 that guides the guide laser so that the processing laser and the guide laser are coaxial, an optical scanning unit 18 that scans the processing laser and the guide laser, and optical scanning An optical scanning control unit 58 that drives and controls the unit 18, and an irradiation position of the processing laser that is shifted in the radial direction and a guide for the processing laser that is incident on the center of the fθ lens 20 on the processing target W A deviation amount calculation unit 54 that calculates a deviation amount from the laser irradiation position, and a correction unit 56 that corrects the irradiation position of the guide laser using the calculated deviation amount. .
[Selection] Figure 5

Description

  The present invention relates to a laser processing apparatus that processes a processing object by irradiating a processing laser.

  Conventionally, in a laser processing apparatus, the irradiation position of a processing laser and the processing target object are irradiated by irradiating the processing target object with guide light that is visible light before actually irradiating the processing target object with the processing laser. It is known to perform positioning and processing size determination.

  Further, the laser processing apparatus is provided with an fθ lens that functions as a converging lens for converging the laser to the focal position, and the fθ lens causes the laser to form an image on a processing object disposed at the focal length. To form an irradiation spot. The position of this irradiation point becomes the irradiation position.

  In this case, since the processing laser uses light having a wavelength other than visible light (for example, light having an infrared wavelength), the refractive index of the visible light laser in the fθ lens is different from the refractive index of the processing laser. For this reason, the irradiation position of the visible light laser is shifted from the irradiation position of the processing laser, and the function as the guide light is impaired.

  In order to solve such a problem, Patent Document 1 shown below describes a deviation between the irradiation position of the processing laser and the irradiation position of the visible light laser at each lattice point of the orthogonal coordinate system set on the processing plane. If the irradiation position of the visible light that is the guide light corresponds to the lattice point, the irradiation position is corrected using the data in the data table, and the irradiation of the guide light is performed. If the position is other than the grid point, the irradiation position is corrected using data obtained by interpolation using data related to the grid point. Thereby, the deviation between the irradiation position of the guide light and the actual irradiation position of the processing laser is eliminated.

Japanese Patent No. 3494960

  However, in the technique described in Patent Document 1 described above, in order to create the data table, it is necessary to measure the irradiation positions of the visible light laser and the processing laser, which is troublesome. In addition, since the measured value is different for each fθ lens, it must be measured again when the laser processing apparatus is initialized or the lens is replaced. Further, when the irradiation position of the guide light is other than the grid point, the correction of the irradiation position is performed using the data obtained by the interpolation using the data related to the grid point, so that the correction accuracy is lowered.

  Therefore, the present invention has been made in view of the above-described conventional problems, and provides a laser processing apparatus that can easily improve the correction accuracy of the irradiation position of the visible light laser without having a data table. For the purpose.

  In order to achieve the above-mentioned object, the present invention performs processing on the processing object by converging the processing laser emitted from the processing laser emitting section with a converging lens and irradiating the processing object. A laser processing apparatus, a guide laser emitting unit for emitting a guide laser in a visible light wavelength band used for visually confirming an irradiation position of the processing laser, the processing laser, and the guide An optical guide that guides the guide laser, an optical scanning unit that scans the processing laser and the guide laser, and an optical scanning that drives and controls the optical scanning unit A control unit and an irradiation position and a gap of the processing laser that are shifted in the radial direction with the irradiation position on the processing target of the processing laser incident on the center of the convergent lens as an origin. A deviation amount calculating unit for calculating a deviation amount from the irradiation position of the laser for machining by a mathematical expression obtained by series expansion with a power series of a radius that is a distance between the irradiation position of the processing laser and the origin, and the calculated deviation amount And a correction unit that corrects the irradiation position of the guide laser, and the optical scanning control unit scans the guide laser based on the corrected irradiation position.

  The deviation amount calculation unit is characterized in that the deviation amount is calculated using up to a predetermined term in the mathematical expression expanded in series shown in the following formula 1.

（但し、Ａ（ｒ）：半径方向のズレ量，Ｋ_２、Ｋ_４、・・・Ｋ_２ｎ：係数，ｒ：加工用レーザの照射位置と原点との距離）

(Where A (r): radial deviation, K ₂ , K ₄ ,... K _2n : coefficient, r: distance between the processing laser irradiation position and the origin)

  The deviation amount calculation unit calculates the deviation amount using the following equation (2).

  According to the present invention, attention is paid to the fact that the displacement of the irradiation position of the guide laser L2 with respect to the processing laser L1 occurs in the radial direction, and the irradiation position of the processing laser L1 shifted in the radial direction and the irradiation of the guide laser L2. Since the positional deviation amount A (r) is obtained by a mathematical expression that is series-expanded with a power series of the radius that is the distance between the irradiation position of the processing laser and the origin, it is not necessary to have a complicated table, and it is easy. In addition, it is possible to improve the correction accuracy of the irradiation position of the guide laser L2.

It is a schematic block diagram of the laser processing apparatus of embodiment. It is a figure which shows an example of the process pattern printed on the workpiece W by the process laser, and the process pattern which emerges by the scanning of the guide laser when the process pattern data is the same. It is a figure for demonstrating correction | amendment of the irradiation position of this Embodiment. It is a functional block diagram of the control part shown in FIG. It is a flowchart which shows operation | movement of the control part at the time of simulation of printing.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a laser processing apparatus according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a laser processing apparatus 10 according to an embodiment. The laser processing apparatus 10 includes a processing laser light source (processing laser emitting unit) 12 that generates and emits a processing laser (for example, a CO ₂ gas laser that is a gas laser, a YAG laser that is a fixed laser, etc.) L1, and a visible laser beam. A guide laser light source (guide laser emitting portion) 14 that generates and emits a laser (guide laser) L2 in the light wavelength band, and the processing laser L1 and the guide laser L2 are coaxial. A beam combiner (light guide unit) 16 that guides the guide laser L2, and an optical scanning unit 18 that scans the processing laser L1 and the guide laser L2 to change the irradiation positions of the processing laser L1 and the guide laser L2. And the fθ lens (converging lens) 20 that converges the processing laser L1 and the guide laser L2 into spot light, and the laser processing apparatus 10 as a whole. Gosuru information processing apparatus such as a computer (e.g., CPU) and a control unit 22 composed of.

  The beam combiner 16 transmits the processing laser L <b> 1 emitted from the processing laser light source 12 and enters the light scanning unit 18. In addition, the beam combiner 16 reflects the guide laser L2 emitted from the guide laser light source 14 and makes it incident on the optical scanning unit 18. Thereby, the beam combiner 16 can make the processing laser L1 and the guide laser L2 coaxial.

  The optical scanning unit 18 changes the irradiation position of the incident processing laser L1 and the guide laser L2 on the processing target W. The galvano scanner 32x changes the irradiation position on the processing target W in the x-axis direction. And a galvano scanner 32y that changes the irradiation position in the y-axis direction. The galvano scanner 32x includes a galvanometer mirror 34x and a drive motor 36x that rotatably supports the galvanometer mirror 34x. The galvano scanner 32y includes a galvano mirror 34y and a drive motor 36y that rotatably supports the galvano mirror 34y. The galvanometer mirror 34y is provided such that the processing laser L1 and the guide laser L2 reflected by the galvanometer mirror 34x are incident on the workpiece W. The light reflected by the galvanometer mirror 34 y is incident on the object to be processed through the fθ lens 20.

  When the drive motor 36x rotates the galvanometer mirror 34x (by changing the rotation position), the irradiation positions of the processing laser L1 and the guide laser L2 on the processing target W are moved in the x-axis direction. be able to. The drive motor 36y rotates the galvanometer mirror 34y (by changing the rotation position), thereby moving the irradiation positions of the processing laser L1 and the guide laser L2 on the workpiece W in the y-axis direction. be able to. As described above, the drive motors 36x and 36y rotate the galvanometer mirrors 34x and 34y, whereby the machining laser L1 and the guide laser L2 on the workpiece W can be scanned.

  The fθ lens 20 forms an image of the incident processing laser L1 and the guide laser L2 on the surface of the processing target W disposed at the focal length of the fθ lens 20.

  The control unit 22 drives and controls the processing laser light source 12, the guide laser light source 14, and the drive motors 36x and 36y, thereby scanning the processing laser L1 and the guide laser L2 onto the processing target W. The processing laser L1 and the guide laser L2 are irradiated. The control unit 22 irradiates the processing laser L1 at an irradiation position based on processing pattern data (data indicating characters such as alphanumeric characters to be printed by processing, print patterns such as figures and symbols, print size, and print position). The drive motors 36x and 36y are driven and controlled as described above.

  An input device 40 is connected to the control unit 22, and the input device 40 is used for inputting various data to the control unit 22, and a keyboard and mouse for the user to input data. Or an input interface such as a touch panel. The input device 40 may be configured with a personal computer or the like. The input device 40 inputs at least machining pattern data to the control unit 22.

  The storage unit 42 can store information such as a hard disk drive, ROM, RAM, and EEPROM, and stores processing pattern data input by the input device 40. A predetermined program is stored in the storage unit 42, and functions as the laser processing apparatus 10 of the present embodiment when the control unit 22 reads the predetermined program.

  The controller 22 displays a print pattern to be laser processed on the workpiece W by using the guide laser L2 before performing the laser processing using the processing laser L1. Thereby, the printing simulation by laser processing can be performed. Specifically, the control unit 22 drives the guide laser light source 14 and the drive motors 36x and 36y on the basis of the processing pattern data input by the input device 40, thereby causing the guide laser on the processing target W. L2 is repeatedly scanned. By repeating scanning at a speed higher than a certain level, a print pattern based on the machining pattern data emerges (drawn) on the workpiece W, and the user can perform a printing pattern before the laser machining in advance (print pattern to be machined). , Its size and position, etc.) can be visually recognized on the workpiece W.

  The user observes the print pattern or the like that has emerged on the workpiece W and determines whether or not there is a problem with the print pattern, print size, print position, and the like. When the print pattern, print size, print position, and the like are different from those desired, the user can correct the processing pattern data by operating an input interface provided in the input device 40.

  After completion of the printing simulation, the control unit 22 causes the surface of the workpiece W to be laser processed by using the processing laser L1 to print a print pattern. Specifically, the control unit 22 drives the machining laser light source 12 and the drive motors 36x and 36y based on the machining pattern data input by the input device 40, thereby scanning the machining laser L1 and machining. Laser processing is performed on the surface of the object W. As a result, a machining pattern is printed on the surface of the workpiece W.

  Here, as described above, since the guide laser L2 uses a laser in the wavelength band of visible light, the refractive index of the fθ lens 20 is larger than that of the processing laser L1, which often has an infrared wavelength. That is, the refractive index of the fθ lens 20 increases as the wavelength becomes shorter. As a result, the scanning position of the guide laser L2 on the workpiece W and the irradiation position of the machining laser L1 on the workpiece W are misaligned. Therefore, even if the machining pattern data is the same, the machining pattern that emerges by scanning with the guide laser L2 is actually the machining pattern printed on the workpiece W by scanning the machining laser L1. Different.

  FIG. 2 is a diagram illustrating an example of a machining pattern printed on the workpiece W by the machining laser L1 and a machining pattern that emerges by scanning with the guide laser L2 when the machining pattern data is the same. .

  A solid line indicates a processing pattern printed on the processing target W by the processing laser L1, and a dotted line indicates a processing pattern that floats on the processing target W by the guide laser L2. The processing pattern printed by the processing laser L1 is the English letter “E”, but the processing pattern drawn by the guide laser L2 is distorted by the letter “E”. Further, since the guide laser L2 has a higher refractive index in the fθ lens 20 than the processing laser L1, the size of the processing pattern drawn by the guide laser L2 is the processing pattern printed by the processing laser L1. Smaller.

  In order to make the processing pattern drawn by the guide laser L2 the same as the processing pattern printed by the processing laser L1, in the printing simulation, the processing pattern data is corrected and the drive motors 36x and 36y are driven. .

  FIG. 3 is a diagram for explaining correction of the irradiation position according to the present embodiment. When the rotational positions of the drive motors 36x and 36y are the same, the irradiation position where the processing laser L1 passes through the fθ lens 20 and is irradiated onto the workpiece W, and the guide laser L2 passes through the fθ lens 20. The irradiation position irradiated on the workpiece W is preferably the same, but is shifted due to the refractive index of the fθ lens 20.

  The guide laser L2 having a short wavelength has a higher refractive index in the fθ lens 20 than the processing laser L1, and is refracted inward relative to the irradiation position on the processing target W of the processing laser.

  The deviation of the irradiation position of the guide laser L2 from the processing laser L1 is considered to be zero at the center of the fθ lens 20. That is, the refractive index is substantially the same at the center of the fθ lens 20, and the irradiation position of the guide laser L2 incident on the center of the fθ lens 20 and the irradiation position of the processing laser L1 are considered to be approximately the same. Accordingly, the irradiation position of the processing laser L1 incident on the center of the fθ lens 20 is set as the origin, and the distance between the irradiation position of the guide laser L2 and the processing laser L1 increases as the distance from the origin is increased.

  Further, since the positional deviation of the irradiation position caused by the refractive index difference depending on the wavelength of the fθ lens 20 occurs in rotational symmetry, the two-dimensional polar coordinates (r, θ) are suitable instead of the (x, y) coordinates. It is considered that the deviation amount A of the irradiation position of the guide laser L2 with respect to the processing laser L1 by the fθ lens 20 always shifts in the r (radius) direction and hardly shifts in the θ (rotation) direction. Therefore, the deviation amount of the irradiation position of the guide laser L2 with respect to the processing laser L1 by the fθ lens 20 can be expressed by A (r). The deviation A (r) means that it is a function of only r regardless of θ.

When the shift amount A (r) is expanded in series with the power series of r, it can be expressed as follows. Note that K ₁ , K ₂ , K ₃ ,... Are coefficients, and r indicates the distance between the irradiation position of the processing laser and the origin.

Considering that the deviation A (r) is generated by the fθ lens 20 that is a smooth curved surface, there are two restrictions on the series K. As a first restriction, as described above, since the deviation amount of the irradiation position of the processing laser L1 with respect to the guide laser L2 is considered to be 0 at the center (r = 0) of the fθ lens 20, K ₀ = 0. . That is, the positional deviation of the irradiation position caused by the refractive index difference due to the wavelength of the fθ lens 20 occurs in a rotationally symmetrical manner, so the deviation direction cannot be defined at the center of rotation, and the deviation amount A (r) including the direction is r = In order to be continuous at 0, r = 0 and the value of A (r) must be 0.

  As a second restriction, the deviation amount A (r) of the guide laser L2 with respect to the processing laser L1 is on the x-axis where y = 0, and when r> 0, the deviation amount A (r) This is the same function as the deviation amount A (x) in which the amount is represented by (x, y) coordinates. However, considering up to the negative region of x, A (x) must be smooth in the entire region of x and symmetric with respect to ± inversion of x. Therefore, when considering two constraints, the deviation amount A (r) can be expressed as follows.

  Since sufficient accuracy can be obtained with only the first term of the series expansion, in this embodiment, the deviation A (r) can be expressed as follows.

Therefore, if measured prior to the value of K ₂ for each fθ lens 20, it is possible to determine the amount of deviation of the guide laser L2 for any of the irradiation position (r, theta). The drive motors 36x and 36y may be driven so that the processing laser L1 is irradiated to the irradiation position (r, θ) while the guide laser L2 is irradiated to the irradiation position (r + A (r), θ). For example, the irradiation position of the processing laser L1 and the irradiation position of the guide laser L2 can be made the same.

  FIG. 4 is a functional block diagram of the control unit 22. The control unit 22 includes a processing pattern data acquisition unit 50, an irradiation position calculation unit 52, a deviation amount calculation unit 54, a correction unit 56, and an optical scanning control unit 58.

  The machining pattern data acquisition unit 50 acquires the machining pattern data input by the input device 40. The processing pattern data acquisition unit 50 outputs the acquired processing pattern data to the irradiation position calculation unit 52.

  The irradiation position calculation unit 52 calculates a plurality of irradiation positions (x, y) based on the processing pattern data (print pattern, print size, print position, etc.). In this case, the origin of the xy coordinates is set to the irradiation position of the processing laser L1 incident on the center of the fθ lens 20. That is, the origin on the xy coordinate and the origin on the rθ coordinate are the same. The irradiation position calculation unit 52 outputs the calculated irradiation position to the deviation amount calculation unit 54 and the optical scanning control unit 58. The optical scanning control unit 58 drives and controls the processing laser light source 12 and controls the optical scanning unit 18 based on the calculated plurality of irradiation positions (x, y). Thereby, the processing laser L1 can be irradiated to a plurality of irradiation positions (x, y).

  The deviation amount calculation unit 54 calculates the deviation amount A (r) of the irradiation position of the guide laser L2 when the guide laser L2 is irradiated based on the calculated irradiation position (x, y). Specifically, the irradiation position (x, y) of the processing laser L1 is converted into a coordinate system of polar coordinates (r, θ). Then, the shift amount A (r) is calculated from the converted r using Equation 5. Conversion from the xy coordinate to the rθ coordinate can be performed using a function of x = r × sin θ, y = r × cos θ.

  The correction unit 56 corrects the irradiation position (x, y) using the calculated deviation amount A (r). Specifically, the calculated deviation amount A (r) is added to the irradiation position (r, θ) at the rθ coordinate to calculate the corrected irradiation position (r ′, θ) at the rθ coordinate. The corrected irradiation position (r ′, θ) in the rθ coordinate is (r + A (r), θ). Then, the corrected irradiation position (r ′, θ) on the calculated rθ coordinate is converted into an xy coordinate. The corrected irradiation position (x ′, y ′) after conversion into xy coordinates is (r ′ cos θ, r ′ sin θ). The correction unit 56 outputs the corrected irradiation position to the optical scanning control unit 58.

  The optical scanning control unit 58 drives and controls the guide laser light source 14 and controls the optical scanning unit 18 based on the calculated irradiation positions (x ′, y ′) after correction, thereby processing the optical scanning unit 58. The guide laser L2 can be irradiated to the irradiation position (x, y) based on the pattern data.

  Next, the operation of the control unit 22 during printing simulation will be described with reference to the flowchart of FIG. The machining pattern data acquisition unit 50 acquires the machining pattern data input by the input device 40 (step S1).

  Next, the irradiation position calculation unit 52 calculates a plurality of irradiation positions (x, y) on the xy coordinates based on the acquired processing pattern data (step S2).

  Next, the deviation amount calculation unit 54 converts the plurality of calculated irradiation positions on the xy coordinates into irradiation positions (r, θ) on the rθ coordinates (step S3). This conversion can be performed using a function of x = r × sin θ and y = r × cos θ.

  Next, the deviation amount calculation unit 54 calculates the deviation amount A (r) at each irradiation position (r, θ) using Equation 5 from r of the plurality of irradiation positions (r, θ) converted in step S3. Calculate (step S4).

  Next, the correction unit 56 uses the respective irradiation positions (r, θ) and the calculated deviation amount A (r) at the respective irradiation positions (r, θ) to correct the irradiation positions ( A plurality of r ′, θ) are calculated (step S5). Specifically, the calculated deviation A (r) is added to the irradiation position (r, θ) on the rθ coordinate to calculate (r ′, θ). The corrected irradiation position (r ′, θ) = (r + A (r), θ).

  Next, the correcting unit 56 converts the plurality of corrected irradiation positions (r ′, θ) on the calculated rθ coordinates into irradiation positions (x ′, y ′) on the xy coordinates (step S6). The irradiation position (x ′, y ′) on the xy coordinates is (r ′ cos θ, r ′ sin θ) = ((r + A (r)) cos θ, (r + A (r)) sin θ).

  Next, the light scanning controller 58 scans the guide laser L2 based on the corrected irradiation position (x ′, y ′) (step S7). Specifically, the drive laser light source 14 is driven and controlled, and the optical scanning unit 18 is driven and controlled based on the corrected irradiation position (x ′, y ′). Thereby, the guide laser L2 can be irradiated to a plurality of irradiation positions (x, y) based on the processing pattern data.

  When the printing simulation is completed, the optical scanning control unit 58 drives and controls the processing laser light source 12 and controls the optical scanning unit 18 so that the processing laser L1 is irradiated to a plurality of irradiation positions (x, y). Drive control.

  Thus, in the present embodiment, focusing on the fact that the displacement of the irradiation position of the guide laser L2 with respect to the processing laser L1 occurs in the radial direction, the irradiation position of the processing laser L1 shifted in the radial direction and the guide laser Since the deviation amount A (r) of the irradiation position of the laser L2 is obtained by a mathematical expression that is series-expanded with a power series of a radius that is the distance between the irradiation position of the processing laser L1 and the origin, a complicated table is bothered. The correction accuracy of the irradiation position of the guide laser L1 can be easily improved.

Further, since the deviation amount A (r) can be obtained using only the first term of the series expansion, it is only necessary to measure the coefficient K ₂ in advance, and it is not necessary to have a complicated table. The correction accuracy of the irradiation position of the laser L2 can be improved.

  In the above embodiment, the shift amount A (r) is calculated using only the first term of the series expansion, but it is obtained using a predetermined term (for example, from the first term to the second term). You may do it. Even in this case, it is not necessary to have a complicated table, and the correction accuracy of the irradiation position of the guide laser L2 can be easily improved.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Laser processing apparatus 12 ... Processing laser light source 14 ... Guide laser light source 16 ... Beam combiner 18 ... Optical scanning part 20 ... f (theta) lens 32x, 32y ... Galvano scanner 34x, 34y ... Galvano mirror 36x, 36y ... Drive motor 40 ... Input device 42 ... Storage unit 50 ... Processing pattern data acquisition unit 52 ... Irradiation position calculation unit 54 ... Deviation amount calculation unit 56 ... Correction unit 58 ... Optical scanning control unit

Claims (3)

A laser processing apparatus that performs processing on the processing object by converging the processing laser emitted from the processing laser emitting unit with a converging lens and irradiating the processing object,
A guide laser emitting section for emitting a guide laser in the wavelength band of visible light used for visually confirming the irradiation position of the processing laser;
A light guide portion for guiding the guide laser so that the processing laser and the guide laser are coaxial;
An optical scanning section for scanning the processing laser and the guide laser;
An optical scanning control unit that drives and controls the optical scanning unit;
The amount of deviation between the irradiation position of the processing laser and the irradiation position of the guide laser, which is shifted in the radial direction, with the irradiation position on the processing object of the processing laser incident on the center of the convergent lens as the origin, is used for processing. A deviation amount calculating unit that calculates a mathematical expression that is a series expansion of a power series of a radius that is a distance between a laser irradiation position and the origin;
A correction unit that corrects the irradiation position of the guide laser using the calculated shift amount;
With
The optical scanning control unit scans the guide laser based on the corrected irradiation position. The laser processing apparatus according to claim 1,
The deviation amount calculation unit calculates a deviation amount by using up to a predetermined term in the series expanded mathematical expression shown in the following formula 1.

(Where A (r): radial deviation, K ₂ , K ₄ ,... K _2n : coefficient, r: distance between the processing laser irradiation position and the origin) The laser processing apparatus according to claim 2,
The deviation amount calculation unit calculates the amount of deviation using the following equation (2).

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