KR20190122515A - Apparatus for automatically correcting the position of laser scanning system - Google Patents

Abstract

The present invention relates to an automatic position correction apparatus for laser scanning equipment and, more specifically, to an automatic position correction apparatus for laser scanning equipment using position measurement modules for detecting minimal laser beam emission positions to alleviate a composite offset or a drift of a gain created by a laser, a scanner, and an optical unit by effects of mechanism, heat, and noise in laser scanning equipment. The automatic position correction apparatus for laser scanning equipment comprises: a laser beam source to transmit a laser beam in a first direction perpendicular to an X-Y plane on which a machining surface of a workpiece is positioned; a first mirror to emit a laser beam from the laser beam source in a prescribed angle range in a plane direction of a second direction maintaining a prescribed angle with respect to the first direction; a second mirror to emit the laser beam reflected from the first mirror to a machining surface of a rectangular shape; a first and a second motor to rotate the first and the second mirror; one or more position measurement modules arranged at real emission positions of the laser beam determined by four independent position parameters of the machining surface where the laser beam is to be emitted to the workpiece and four independent position parameters to detect laser beam emission positions; and a correction unit to generate a signal to drive one or more among the first and the second motor to correct one or more among an offset and a drift of a gain of the position parameters and real positions.

Description

Apparatus for automatically correcting the position of laser scanning system}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic position correcting apparatus for laser scanning equipment, wherein the complex offset or gain generated in the laser, scanner, and optics by the influence of instruments, heat, and noise in the laser scanning equipment. An automatic position correcting apparatus for laser scanning equipment using a position measuring module for detecting a minimum laser beam irradiation position to improve drift.

In general, laser scanning equipment is used for a variety of purposes, in particular marking, labeling, cutting, drilling, sintering or welding. In various applications of laser material processing, it is advantageous to control the laser bin incidence angle on the workpiece at high speed through a scanner.

Due to these advantages, a micromachining system for processing a material or marking a surface of the material by using a laser beam is widely used. In particular, in the micro or nano-machining process, in order to increase the precision of processing, The control precision of the laser scanner is highly required.

Such a laser beam scanner is provided with an X-axis scanner and a Y-axis scanner when it is necessary to deflect the laser beam emitted from the laser oscillator in the X-axis and Y-axis directions, thereby driving the X-axis scanner and the Y-axis scanner, respectively. X-axis driver and Y-axis driver are provided for the purpose, and the X-axis scanner and Y-axis scanner are offset and gain due to the distortion of the laser beam and the optical element and the mirror of the laser beam scanner. There is a problem that a drift of gain occurs.

However, it is composed of a reflection mirror reflecting the laser beam constituting the laser beam scanner at a predetermined angle and a scanner motor (galvano motor) which rotates the reflection mirror to adjust the angle of the reflection mirror. The variation of the reflection mirror due to the change of the resistance is one of the main factors affecting the current flowing in the coil of the micro motor, the value of which changes as the temperature changes, thereby controlling the exact angle of the reflection mirror of the laser beam scanner. This causes an error in the control accuracy of the laser beam scanner.

As a conventional technique for solving this problem, if the change rate (temperature coefficient) of the coil resistance according to the unit temperature change is known, the resistance value may be compensated according to the temperature change, but the compensation of the actual resistance value is an error from the compensation method or the measurement of the resistance change rate. In order to compensate for the disadvantage of poor control accuracy, the 'laser head' of Korean Patent Laid-Open Publication No. 2005-0106664 maintains the temperature of the laser beam scanner motor appropriately rather than using a method of compensating the resistance variation rate according to temperature. A method was proposed.

This will be described with reference to FIG. 1, and the scanner block 20 is fixedly installed in the casing 11 of the laser head 10, and the scanner block 20 has an X-axis scanner 21 and a Y-axis scanner ( 22) body is fixedly installed.

Most of the body including the scanner motors 21 and 22 of the scanners 21 and 22 is disposed to be fixed in the scanner block 20, and the temperature in the laser head 10 is adjusted at one side in the laser head 10. The temperature control part 30 is provided. The laser head 10 is a system for irradiating a laser beam emitted from a laser oscillator in a predetermined direction, and performs a laser machining operation on a surface to be processed moved by an X-Y stage. Here, reference numeral 13 denotes a hole in which the laser beam is incident, 14 denotes a reflection mirror in which the incident laser beam is reflected, and 15 denotes a hole on a path from which the laser beam passing through the scanner block 20 goes from the laser head to the work object. to be

However, this conventional technique controls the temperature of the laser beam scanner motor, which is affected by laser irradiation by the temperature inside the laser beam scanner, to be kept constant so that the temperature of the laser beam scanner motor can be controlled quickly, precisely and reliably. In addition, by allowing heating and cooling without being influenced by the ambient temperature, the reflection mirror control accuracy of the laser beam scanner is increased, thereby increasing the reliability of processing in the micro or nano unit and increasing the life of the components constituting the laser beam scanner. Although it is possible to achieve the effect of maintaining a stable temperature inside a simple laser beam scanner, this improvement alone is limited to improve the distortion of the complex offset or gain caused by the influence of the instrument, heat and noise. Due to laser There are some limitations to ensure the precision required for the ball.

The present invention devised to solve the problems of the prior art as described above is a complex offset or gain distortion caused by the influence of the instrument, heat and noise among the environmental elements of the laser beam scanner while using a minimum position measurement module. The purpose is to improve.

An object of the present invention is an automatic position correction device for laser scanning equipment, comprising: a laser beam source for transmitting a laser beam in a first direction perpendicular to an X-Y plane in which a processing surface of a workpiece is located; A first mirror for irradiating a laser beam from the laser beam source in a predetermined angle range in a planar direction of a second direction maintaining a predetermined angle with respect to the first direction; A second mirror for irradiating the laser beam reflected from the first mirror onto a machining surface having a rectangular shape; A first motor and a second motor for rotating the first mirror and the second mirror, respectively; One or more positions disposed at actual irradiation positions of the laser beam determined by four independent position parameters and four independent position parameters of the machining surface on which the laser beam is to be irradiated to the workpiece. A measurement module; And a correction unit generating a signal for driving any one or more of the first motor and the second motor to correct any one or more of the position parameter and the offset or gain misalignment of the actual position. It is achieved by an automatic position correction device for laser scanning equipment.

Accordingly, the automatic position correction device for laser scanning equipment of the present invention is a combination of offsets or gains generated by the influence of the mechanism, heat and noise generated in the laser beam scanner, which is an environmental element of the laser beam scanner. There is an effect to improve the drift while using a minimum position measuring module.

1 is an overall configuration diagram of a laser head including a temperature control device according to the prior art,
2 is a basic explanatory diagram of an automatic position correction device for laser scanning equipment of the present invention for explaining the occurrence of offset and gain distortion;
3 is an explanatory diagram for the offset and gain of the offset and gain of the automatic position correction device of the laser scanning device according to the present invention;
4 is a configuration diagram for the correction of the automatic position correction device of the laser scanning apparatus according to the present invention, and
5 is an exemplary view of the position measurement module of the present invention.

The terms or words used in this specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best describe their invention. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

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

2 is a basic explanatory diagram of an automatic position correcting apparatus of the laser scanning apparatus of the present invention for explaining the occurrence of offset and gain misalignment. As shown in Figure 2, the automatic position correction device of the laser scanning device of the present invention is the machining surface of the object to be processed, such as marking (marking), labeling (cutting), cutting (drilling), sintering or welding is located The laser beam is irradiated from the laser beam source 100 in a first direction perpendicular to the XY plane 310, and the distortion d1 of the laser beam itself is generated.

The laser beam irradiated from the laser beam source 100 generates an optical distortion d2 by an optical lens such as the condenser lens 110, and then the laser beam that has passed through the condenser lens 110 is predetermined with respect to the first direction. The laser beam is distorted from the first mirror 210 in a predetermined angular range in the plane direction of the second direction maintaining the angle (d3), and then the laser beam reflected from the first mirror 210 is processed in the XY plane. The distortion d4 is also generated in the second mirror 220 irradiated by the predetermined area 310 and the position measurement module 400 of the processed surface of the surface.

Here, the first mirror 210 reflects the laser beam from the laser beam source 100 in the upright state in the horizontal direction or the horizontal direction slightly inclined in the horizontal direction, but the predetermined angle by the rotation axis of the first mirror 210. By rotating within the range is irradiated along the reflection line, that is, the irradiation line of the second mirror 220 located on the central axis of rotation of the second mirror 220, the second mirror 220 is formed along the axis of rotation The laser beam on the irradiation line is reflected vertically downward to form a processing area, that is, an irradiation area, on the surface of the object.

A first motor (not shown) which rotates the first mirror 210 and the second mirror 220 to irradiate a laser beam in a predetermined angle range to the first mirror 210 and the second mirror 220; A second motor (not shown) is provided.

Through this, the laser beam sent from the laser beam source 100 is divided into four pieces of P1 (x1, y1), P2 (x2, y2), P3 (x3, y3) and P4 (x4, y4) with respect to the processing surface of the workpiece. A rectangular laser beam irradiation area is formed having vertex coordinates as independent position parameters.

In the present invention, the position measuring module is disposed at any one or more of four independent position parameters in order to detect the laser beam irradiation position using the minimum position measuring module.

3 is an explanatory diagram for the offset and gain of the offset and gain of the automatic position correction device for laser scanning equipment according to the present invention. As shown in FIG. 3, four independent positions of P1 (x1, y1), P2 (x2, y2), P3 (x3, y3) and P4 (x4, y4) with respect to the machined surface of the workpiece in the normal operating state. Forming a rectangular laser beam irradiation area with parameter vertex coordinates, but not the irradiation area to which the laser beam should be irradiated under normal operating conditions due to the influence of mechanisms, heat and noise inside the laser scanning equipment. Four independent positions with P '(x1', y1 '), P2' (x2 ', y2'), P3 '(x3', y3 ') and P4' (x4 ', y4') as vertices with respect to An irradiation area is formed in the area different from the parameter vertex coordinates by the offset and the gain.

One or more of the position measuring modules of the actual irradiation position of the laser beam determined by four independent position parameters and four independent position parameters of the machining surface on which the laser beam is to be irradiated to the object to detect such offset and gain distortion By detecting the laser beam irradiation position by the (400) it is possible to minimize the position measuring module 400.

Here, at least one position measuring module 400 is disposed between the second mirror 220 and the processing surface.

In addition, the arrangement of the two position measuring modules 400 to measure the points P1 and P1 'and the measurement of P4 and P4', respectively, is not limited to this arrangement as an example for explaining the present invention. .

Here, the actual irradiation position of the laser beam determined by the four independent position parameters is detected by the position measuring module 400, which uses an image sensor or a photo diode, which is a precise light sensor, as the imaging sensor 440.

Here, the offset and gain of the irradiation area irradiated with the actual laser beam are calculated as follows.

The offset skew is calculated by the difference between the actual position of the laser beam corresponding to one position parameter P1 and P1 ', and the gain skew is the irradiation area 310 of the laser beam determined by four independent position parameters. The x-axis gain and the y-axis gain are calculated based on the ratio of the length of the x-axis and the y-axis and the length of the x-axis and the y-axis of the laser beam actual irradiation area 320, and the laser beam irradiation area 310 and the laser beam The calculation method of the offset and gain using the vertex coordinates representing the actual irradiation area 320 is calculated as the reference point P1 'point as follows.

Offset x1 = x1-x1 '

Offset y1 = y1-y1 '

Offset x4 = x4-x4 '

Offset y4 = y4-y4 '

Gain x1 = (x1-x4) / (x1'- x4 ')

Gain y1 = (y1-y4) / (y1 '-y4')

Here, the offset value is calculated using the offset x1 and the offset y1 when only one position measuring module 400 is used, and the average value of the offset x1 and the offset x2 is x when two position measuring modules 400 are used. It is used as the direction offset and the average value of the offset y1 and the offset y2 is used as the y direction offset.

In addition, when using two or more position measurement modules 400, the average of the offsets or gains by the diagonals existing between the two or more position measurement modules 400 is used.

When the offset or the gain of the gain is calculated as described above, the second motor attached to the first motor or the second mirror 220 attached to the first mirror 210 so as to correspond to the laser beam irradiation area 310 in a normal operating state. By driving any one or more of the motors, either the offset or the gain misalignment is corrected.

This process is repeatedly performed during the operation of the laser scanner equipment, thereby increasing the accuracy and reproducibility of the laser processing by correcting any misalignment of one or more of offset or gain in real time in the laser scanner equipment. .

4 is a configuration diagram for the correction of the automatic position correction device for laser scanner equipment according to the present invention. As shown in FIG. 4, the automatic position correction device for laser scanner equipment of the present invention includes a first motor and a second mirror 220 attached to the position measurement module 400, the correction unit 500, and the first mirror 210. It is configured to include a second motor attached to the).

Here, the position measuring module 400 acquires an image by capturing the actual laser beam irradiation area 320 using an image sensor or a photodiode, which is a precise optical sensor, and a laser beam should be irradiated to the processing object from the acquired image. The laser beam irradiation position is detected by the at least one position measuring module 400 at the actual irradiation position of the laser beam determined by the four independent position parameters and the four independent position parameters of the machining surface, and is corrected by the correction unit 500. Either one or more of the offset or gain skew should be derived.

Subsequently, the first motor attached to the first mirror 210 and the second motor attached to the second mirror 220 are arranged so that the offset and gain distortion derived from the corrector 500 coincide with the vertex coordinates of the normal operating state. By driving to correct the laser beam irradiation angle of the first mirror 210 and the second mirror 220, it is possible to eliminate the offset and gain skew.

Here, the detection of the position measuring module 400 and the generation of the correction signal of the correction unit 500 are performed in real time at a time interval that maintains within the processing tolerance of the processing target of the laser scanning equipment, which occurs in a short term. The amount of distortion is relatively small, but when the accumulation accumulates over a long term over time, the accuracy of laser processing is significantly lowered due to the accumulation of distortion several times to several tens of times compared to the distortion generated in a short term. Since is generated, by performing in real time at a time interval to maintain the machining tolerance of the object to be processed so that the offset and gain distortion can be maintained within the distortion range generated in a short time.

5 is an exemplary view of the position measurement module of the present invention. As shown in FIG. 5, the position measuring module 400 of the present invention has a laser beam generated from the laser beam source 100 and is incident on the laser beam passing through the laser scanning equipment. The optical filter unit 410 for blocking the light, the optical modified optical unit 420, the optical modified optical unit 420 to enlarge, reduce, change the shape and change the wavelength of the laser beam transmitted by the optical filter unit 410 The light output converter 430 reduces the output of the transmitted laser beam, and the optical sensor unit 440 recognizes the laser beam that has passed through the light output converter 430.

Here, the optical sensor unit 440 preferably uses an optical sensor such as an image sensor, a photodiode, and the like, and the optical modification optical unit 420 and the light output converter 430 may be disposed to be interchanged with each other. It is possible.

Although the present invention has been shown and described with reference to the preferred embodiments as described above, it is not limited to the above embodiments and those skilled in the art without departing from the spirit of the present invention. Various changes and modifications will be possible.

100: laser beam source 110: optical lens
210: first mirror 220: second mirror
310: laser beam irradiation area 320: laser beam actual irradiation area
400: position measuring module 410: optical filter unit
420: optical deformation optical unit 430: light output conversion unit
440: light sensor
500: correction unit

Claims (8)

In the automatic position correction device for laser scanning equipment,
A laser beam source for transmitting a laser beam in a first direction perpendicular to the XY plane in which the processing surface of the object to be processed is located;
A first mirror for irradiating a laser beam from the laser beam source in a predetermined angle range in a planar direction of a second direction maintaining a predetermined angle with respect to the first direction;
A second mirror for irradiating the laser beam reflected from the first mirror onto a machining surface having a rectangular shape;
A first motor and a second motor for rotating the first mirror and the second mirror, respectively;
One or more positions disposed at actual irradiation positions of the laser beam determined by four independent position parameters and four independent position parameters of the machining surface to which the laser beam is to be irradiated to the object to be processed. A measurement module; And
And a correction unit generating a signal for driving any one or more of the first motor and the second motor to correct any one or more of the position parameter and the offset or gain misalignment of the actual position. Automatic position correction device for scanning equipment.
The method of claim 1,
At least one position measuring module is disposed between the second mirror and the processing surface, automatic position correction apparatus for laser scanning equipment.
The method of claim 2,
The position measuring module is a laser scanning field, characterized in that the laser beam passing through the optical filter unit, the optical modification optical unit, the light output conversion unit is irradiated to the optical sensor unit and the incident of the laser beam passing through the second mirror directly. Cost automatic position correction device.
The method of claim 3,
And the optical sensor unit is any one of an image sensor and a photodiode.
The method of claim 1,
The offset misalignment is calculated using a single position measuring module automatic position correction apparatus for laser scanning equipment.
The method of claim 1,
In the case of measuring the offset and the gain skew, the automatic position correction device for laser scanning equipment, characterized in that for calculating the average value using two or more position measurement modules.
The method of claim 1,
The gain skew is the length of the x and y axes of the laser beam irradiation area and is measured and calculated by the positioning module arranged diagonally among four independent position parameters and the x and y axes of the laser beam actual irradiation area. An automatic position correction device for laser scanning equipment, comprising calculating the x-axis gain and the y-axis gain skew by the ratio of the lengths.
The method of claim 1,
The detection of the two position measuring modules and the generation of the correction signal of the correction unit is automatic position correction device for laser scanning equipment, characterized in that performed in real time at a time interval to maintain within the processing tolerance of the processing object.

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