JP2002001563A - Laser processing apparatus and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a processing precision and minimize an unevenness of a processing precision between processing unit adjacent irrespective of a flatness of a processing surface. SOLUTION: In each processing unit on an orifice plate, a distance is measured by a distance sensor. (Step S1 to S5) Then, the measured difference of each distance data is adjusted based on the each measured distance data by means of calculation for a proximate curve of the each distance data and an average movement data. (Step 6) By controlling z stage using the adjusted data of the each distance, while a laser beam is controlled to a most suitable focus position by focusing in each processing unit, (Step 8) a laser processing is performed. (Step 9 to S12).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus and method for performing laser processing by irradiating a workpiece with a laser.

[0002]

2. Description of the Related Art Hitherto, an orifice, which is an ink ejection hole in an ink jet printer head, has been formed in an orifice plate by a plating method called electroforming. Then, in the manufacturing process of the ink jet print head, the orifice plate after the formation of the orifice is bonded to a predetermined portion at the end of the housing of the ink jet printer head.

However, since an ordinary ink jet print head is required to have a printing resolution of 300 dpi or more, the arrangement pitch of the orifices (hole spacing between adjacent orifices) is about 80 μm or less, and a very fine structure. It has become. Therefore, in the step of bonding the orifice plate to the ink-jet housing, there is a problem that the adhesive flows into the orifice that has already been formed, which causes clogging of the holes and hinders the ink from flying. Further, in order to prevent this trouble, the arrangement pitch cannot be narrowed, and the dot intervals become sparse, so that there is a problem that the sharpness of printing is impaired.

In order to solve these problems, when manufacturing an ink jet printer head, an orifice plate made of a polymer resin is adhered to a predetermined portion at an end of a housing of the ink jet printer head, and then the orifice plate is laser-processed. The technique of forming is also being performed.

For example, Japanese Patent Application Laid-Open No. Hei 5-330064 discloses a technique in which a laser beam is applied to an orifice plate from the ink ejection side to form only an inverted tapered portion in the orifice.

[0006] Japanese Patent Application Laid-Open No. 10-291318 discloses a technique of irradiating a laser to form a large number of nozzles at once.

[0007]

However, in the above-mentioned conventional technique of forming an orifice by laser processing, the quality of the orifice cannot be sufficiently stabilized. In other words, in the actual manufacturing process of the orifice, unless the laser is irradiated by sufficiently grasping the distance to the processing point, the focus position of the laser is not constant, and the formed orifices vary, so that There is a problem that the ejection performance of each orifice varies in the ink jet head.

That is, when a large number of orifice holes are divided into a plurality of processing units and laser irradiation is performed for each processing unit, it is necessary to grasp the distance to the processing point for each processing unit. If the difference in the distance between the processing units to be performed is large, or if the distance measurement shows an irregular value,
A phenomenon occurs in which the ejection performance of ink droplets at the orifice of the processing unit differs from that of the other processing unit.

In recent years, the spread of ink jet printers for forming full-color images has been rapidly expanding, and higher printing performance has been required. Therefore, the hole pitch of each orifice has been narrowed. On the other hand, there is an increasing demand for forming an orifice that enables ink droplets to fly with high straightness.

An object of the present invention is to provide a laser processing technique having higher processing accuracy than the conventional one.

An object of the present invention is to provide a laser processing technique in which the processing accuracy can be more easily improved.

An object of the present invention is to improve processing accuracy, particularly when the flatness of a processing surface is high,
An object of the present invention is to provide an effective laser processing technique even when a processing surface is inclined.

An object of the present invention is to reduce the variation in processing accuracy between adjacent processing units, to change the degree of influence of irregular values of distance data,
Another object of the present invention is to provide a laser processing technique which is more effective especially when the plane accuracy of the processing surface is low.

An object of the present invention is to provide a laser processing technique which can reduce the variation in processing accuracy between adjacent processing units and is particularly effective when the plane accuracy of a processing surface is high.

[0015]

According to a first aspect of the present invention, there is provided a laser generator for irradiating a work to generate a laser for laser processing, and an optical system for forming an image of the laser on a processing point of the work. System, a position moving device that moves a position where the laser processing is performed on the work, and by controlling the position moving device and the laser generating device, the processing is performed in a plurality of processing units whose positions are changed. Processing control means for performing, a measuring means for measuring the distance to the processing point with a distance sensor for each processing unit, a focus position variable device for changing the focus position of the laser with respect to the processing point, and this focus position variable device Controlling a focus position adjusting means for adjusting the focus position for each processing unit based on each distance data after the measurement; And correcting means for correcting the measurement error of the distance data based on a plurality of distance data, a laser processing device comprising a.

Therefore, the laser processing can be performed by changing the focus position with respect to the processing point of the laser by using the respective distance data in which the measurement error is corrected based on a plurality of distance data measured for each processing unit. However, it is possible to perform laser processing higher than before.

According to a second aspect of the present invention, in the laser processing apparatus according to the first aspect, the focus position changing device moves a position of the work in an optical axis direction of the laser light applied to the work. By doing so, the focus position is changed.

Therefore, the focus position can be easily changed by controlling the optical system as compared with the case where the focus position is changed, and the processing accuracy can be further improved.

According to a third aspect of the present invention, in the laser processing apparatus according to the first or second aspect, the correction means comprises:
The correction is performed by obtaining an approximate curve of each distance data after the measurement and using the value of the approximate curve as the respective distance data.

Therefore, particularly when the flatness of the processing surface is high, the influence of the irregular value of the distance data can be reduced, and the processing accuracy can be improved. It is also effective when the machined surface is inclined.

According to a fourth aspect of the present invention, in the laser processing apparatus according to the first or second aspect, the correction means comprises:
The correction is performed by obtaining a moving average value of each distance data after the measurement, and using each moving average value as the distance data.

Therefore, the influence of the irregular value of the distance data can be reduced, and the variation in processing accuracy between adjacent processing units can be reduced. Further, by changing the number n for taking the moving average, the degree of influence of the irregular value of the distance data can be changed. further,
Since it shows a value close to the actually measured value, it is more effective especially when the plane accuracy of the processed surface is low.

According to a fifth aspect of the present invention, in the laser processing apparatus according to any one of the first to fourth aspects, the correction means includes a predetermined numerical value among the distance data after the measurement. The correction is performed using the distance data after the exclusion of the data outside the range.

Accordingly, the irregularity of the distance data is not affected, so that the variation in machining accuracy between adjacent machining units can be reduced.
It is particularly effective when the plane accuracy of the processed surface is high.

According to a sixth aspect of the present invention, in a plurality of processing units whose positions are changed by moving a position where the laser processing is performed on the work, a laser is imaged at a processing point of the work and processing is performed. A processing step to be performed, a measurement step of measuring a distance to the processing point with a distance sensor for each processing unit before this processing step, and each time the laser processing is performed for each processing unit in the processing step, A focus position adjusting step of adjusting a focus position of the laser with respect to the processing point based on each distance data after the measurement, and a measurement error of each distance data based on the plurality of distance data before the focus position adjusting step. And a correcting step for correcting.

Therefore, the laser processing can be performed by changing the focus position with respect to the processing point of the laser by using each distance data in which the measurement error is corrected based on a plurality of distance data measured for each processing unit. However, it is possible to perform laser processing higher than before.

According to a seventh aspect of the present invention, in the laser processing method according to the sixth aspect, the focus position adjusting step includes moving the position of the work in an optical axis direction of the laser light applied to the work. By doing so, the focus position is changed.

Therefore, the focus position can be easily changed by controlling the optical system as compared with the case where the focus position is changed, and the processing accuracy can be further improved.

According to an eighth aspect of the present invention, in the laser processing method according to the sixth or seventh aspect, the focus position adjusting step obtains an approximate curve of each distance data after the measurement and calculates a value of the approximate curve. Are used as the respective distance data to perform the correction.

Therefore, particularly when the flatness of the processing surface is high, the influence of the irregular value of the distance data can be reduced, and the processing accuracy can be improved. It is also effective when the machined surface is inclined.

According to a ninth aspect of the present invention, in the laser processing method according to the sixth or seventh aspect, the focus position adjusting step calculates a moving average value of each of the distance data after the measurement, and The correction is performed by using a value as the distance data.

Accordingly, the influence of the irregular value of the distance data can be reduced, and the variation in the processing accuracy between adjacent processing units can be reduced. Further, by changing the number n for taking the moving average, the degree of influence of the irregular value of the distance data can be changed. further,
Since it shows a value close to the actually measured value, it is more effective especially when the plane accuracy of the processed surface is low.

The invention according to claim 10 is the invention according to claims 6 to 9
In the laser processing method according to any one of the above, the correcting step excludes a distance out of a preset numerical range among the distance data after the measurement, using the distance data after the exclusion. The above-mentioned correction is performed.

Therefore, the irregularity of the distance data is not affected, so that the variation in machining accuracy between adjacent machining units can be reduced.
It is particularly effective when the plane accuracy of the processed surface is high.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described.

The embodiment of the present invention relates to a laser processing technique. First, FIG. 1 shows a configuration example of an ink jet printer head unit 1 which is an example of a work to be processed. As shown in FIG. 1, an ink jet printer head 3 and a drive circuit board 4 are mounted on a base plate 2. An orifice plate 5 is provided on the front end surface of the ink jet printer head 3.
And the orifice plate 5
A plurality of orifices 6 for discharging ink are formed at a predetermined pitch corresponding to an ink chamber 7 (see FIG. 2) forming a pressure generating chamber.

An ink supply pipe 8 for supplying ink to the ink chamber 7 of the ink jet printer head 3 is provided with a lid 9.
It is attached to a predetermined position. Drive circuit board 4
Is mounted with a drive IC 10 and the like for discharging ink from the orifice 6 by operating an actuator provided in the ink chamber 7 (this embodiment is not limited to an ink jet system, and is not particularly shown). ing. Reference numeral 11 denotes a connection cable for connecting to an external controller (not shown).

FIG. 2 shows an ink jet printer head 3.
3 shows a cross-sectional structure of the orifice plate 5 in FIG.
An orifice 6 is formed in the orifice plate 5 at a position located at an end face of each ink chamber 7 partitioned by a wall 12. The orifice 6 has a tapered shape (three-dimensionally trapezoidal conical shape) with a larger diameter on the inner side (ink chamber 7 side) as viewed from the ink discharge side (outer surface side). The tapered shape so that the diameter on the ink discharge side is reduced is that the actuator provided in the ink chamber 7 is driven to discharge the ink in the ink chamber 7, and the pressure inside the ink chamber 7 is increased. This is to cause the ink to be efficiently discharged when the ink is discharged.

Incidentally, in the orifice plate 5,
A fluorine-containing film 13 is formed on one surface on the ink ejection side (outer surface side), and is configured to have ink repellency.

Next, the configuration of a laser processing apparatus 21 according to an embodiment of the present invention will be described with reference to FIG. The laser processing apparatus 21 performs processing using an excimer laser beam.
An F excimer laser light oscillator 22 is provided. The KrF excimer laser light oscillator 22 has a wavelength of 400 nm.
A pulsed laser beam (excimer laser beam) is output in the following ultraviolet region. This KrF excimer laser light oscillator 2
An optical system of a variable attenuator 23, an up collimator 24, an image rotator 25, a mirror 26, and the like are arranged on the optical path of the laser beam output from the optical system 2, and an array lens illumination system is provided on the reflected optical path of the mirror 26. 27, an optical system of a relay lens 28, a mask 29, and a projection lens 30 are arranged. On the other hand, in the optical axis direction of the projection lens 30, the x stage 31x and the y stage 3
1y and z stages 31z are provided, and the orifice plate 5, which is a work, is mounted on the z stage 31z while being bonded and fixed to an ink jet printer head housing. x stage 31x, y
The stage 31y realizes a position moving device, and the z stage 31z realizes a focus position changing device.

Here, a specific configuration of this optical system extending from the array lens illumination system 27 to the relay lens 28, the mask 29, and the projection lens 30 will be described with reference to FIG. As shown in FIG. 4, an array lens illumination system 27, a relay lens 28, a mask 29, and a projection lens 30 are arranged on the optical path of the excimer laser light. As shown in FIGS. 4 and 5, the array lens illumination system 27 has two cylindrical lens arrays 27a and 27b arranged at an interval L0 in a direction perpendicular to each other.

Each of the light condensing surfaces 32 of the cylindrical lens arrays 27a and 27b (surface including the light converging point)
Correspond to the same plane at a distance L1 from the cylindrical array lens 27b.

The condensing surfaces 32 of the cylindrical lens arrays 27a and 27b are imaged on the surface of the entrance pupil (aperture) 33 of the projection lens 30 by the relay lens 28.
Thereby, a mask 29 is arranged for the array lens illumination system 27, the relay lens 28, the entrance pupil 33, and the projection lens 30 so that a telecentric condition is satisfied for the projection lens 30.

In FIG. 3, the laser processing apparatus 21 is controlled by a fine processing controller 41 which is a computer. That is, the KrF excimer laser light oscillator 22 is controlled by a trigger signal based on laser control,
The variable attenuator 23 is controlled by a fluence control signal, the image rotator 25 is controlled by a rotation speed control signal, and the x stage 31x and the y stage 3
1y is controlled by a position control signal using an xy driver 42. An optical distance sensor 4 is arranged in parallel with the projection lens 30 in the x direction (moving direction of the x stage 31x).
3 is provided, and measures the distance to the processing point of the orifice plate 5. The signal of the distance data detected by the distance sensor 43
Is taken into the micro-machining controller 41 via. The micromachining controller 41 outputs a focus control signal to the autofocus unit 44, and the autofocus unit 44 uses the z stage 31 via the z driver 45.
z is controlled, and the focus position of the laser beam applied to the processing point of the orifice plate 5 is adjusted by moving the z stage 31z up and down.

By irradiating a laser beam from the ink ejection side through such a telecentric optical system,
It is possible to machine the orifice 6 having an inverted tapered shape having an axis perpendicular to the plate surface of the orifice plate 5 and having a larger diameter on the back side.

Next, a series of operations when the laser processing apparatus 21 performs an operation of forming the orifice 6 on the plate surface of the orifice plate 5 will be described with reference to FIGS. First, for example, the orifice 6 of the orifice plate 5
If the number of formed orifices 6 is 200 and 20 orifices 6 can be formed at a time in one processing unit (one laser irradiation) by the laser processing apparatus 21, the orifice plate 5
By moving the processing position above, 10 laser irradiations are required. Therefore, assuming that a processing unit required to form all the orifices 6 on one orifice plate 5 is n, n pieces of laser processing are performed in each processing unit on the processing surface of the orifice 6 as shown in FIG. The areas are referred to as area 1 to area n.

FIG. 7 is a flowchart for controlling the laser processing apparatus 21 performed by the fine processing controller 41. As shown in FIG. 7, the fine processing controller 41 drives the x-stage 31x to move the processing surface of the orifice plate 5 below the distance sensor 43 (Step S1). At this time, the orifice plate 5 is moved to a position where the distance sensor 43 can measure the distance of the processing surface in the area 1. And
The distance to the processing point in area 1 is measured by the distance sensor 43, and the distance data is stored in the RA of the fine processing controller 41.
Stored in M (step S2). Then, the count value C of the predetermined counter (initial value is initially reset to 0) is incremented by +1 (N = N + 1).
(Step S3). If the count value C has not reached n (N in step S4), the x stage 3
1x is driven to move the orifice plate 5 to a position where the distance of the processing surface in the next area can be measured (Step S)
5) Return to step S2.

This process is repeated, and the distance is measured by the distance sensor 43 for all the processing surfaces in the areas 1 to n. When the count value C reaches n (Y in step S4), Move to step S6. Step S1
By S5, the measuring means and the measuring step are realized.

In step S6, based on the n pieces of distance data measured in areas 1 to n, the measurement error of each distance data is corrected. As a result, a correcting means and a correcting step are realized. That is, due to the influence of dust, dirt, and the like, and the difference in surface reflectance, there may be a case where an irregular value is generated among the n pieces of distance data. Then, by including an error in the distance data,
Laser processing in that area is not performed at the optimum focus distance, and the orifice 6 varies depending on the area. Therefore, specifically, the measured distance data is corrected by the following correction means.

Correction means 1: After measuring all distance data,
The average value is obtained, and the average value is used as the distance data of all the areas 1 to n. According to this means, variation in the orifices 6 between adjacent areas is less likely to occur.

Correction means 2: After measuring all distance data,
The approximate straight line is obtained, and the value of the approximate straight line is calculated for each area 1 to
n distance data. In this case, it is possible to cope with a case where the machined surface of the orifice plate 5 is installed at an angle, and the like, and it is difficult for the orifice 6 to vary between the areas. This is a particularly effective correction means when the surface accuracy is high.

Correction means 3: After acquiring all the distance data,
The moving average of each distance data is obtained, and the value is calculated for each area 1 to
n distance data. In this case, it is possible to cope with the case where the machined surface of the orifice plate 5 is installed at an inclination, and the shape of the orifice plate 5 or the like whose surface accuracy is low and the surface itself is distorted follows the shape thereof. Can be processed. The moving average is calculated based on, for example, distance data of three neighboring points. This makes it difficult for the orifices 6 to vary between the areas. This is a particularly effective correction means when the surface accuracy of the orifice plate 5 is low.

9 and 10 show actual measured values of distance data,
The values obtained by correcting the actually measured values by the correction means 1 to 3 are shown. On the horizontal axis, measurement points 1 to 10 of areas 1 to 10
, And the vertical axis indicates the distance indicated by the distance data before and after the correction. FIG. 9 shows an example in which the machined surface of the orifice plate 5 is inclined and the surface accuracy is high. Figure 1
0 indicates an example in which the surface accuracy of the orifice plate 5 is low and distortion occurs.

Correcting means 4: After obtaining all the distance data,
Excluding distance data outside the predetermined numerical value range set in advance,
Using each of the distance data after the exclusion, calculation of a moving average using any one of the means 1 to 3, for example, three adjacent distance data is executed. In the example of FIG.
Is determined as a normal value, the distance data (indicated by a circle) of the point 5 is determined to be an irregular value. When the moving average is calculated without excluding this value, FIG.
The result is as shown in FIG. So we exclude this value,
When a moving average is obtained from three adjacent distance data, a result as shown in FIG. 12 is obtained, and variation in the orifice 6 between the areas can be suppressed.

As described above, the fine processing controller 41 uses the correction value of each distance data obtained in step S6 as a focus control signal,
4, the x-stage 31x is driven to move the orifice plate 5 below the projection lens 30 (step S7). At this time, the orifice plate 5 is moved to a position where the orifice 6 can be formed at a predetermined position on the processing surface of the area 1 by the laser light emitted and projected by the projection lens 30 (see FIG. 8). Then, the Z stage 31z is driven by the autofocus unit 44 based on the correction value of the distance data in the area 1, the focus position of the laser beam is adjusted to an optimum position (step S8), and the KrF excimer laser 22 is controlled. The laser light is output to form the orifice 6 in the area 1 (step S9). Then, the count value C of the predetermined counter is changed (the initial value is initially 0).
), And is incremented by +1 (N = N + 1) (step S10). This count value C
Does not reach n (N in step S11), x
The orifice plate 5 is moved to a position where the orifice 6 in the next area can be formed by driving the stage 31x (step S12), and the process returns to step S8. When the count value C has reached n (Y in step S11), the formation of all the orifices 6 has been completed, and the process ends. Step S8 implements a focus position adjusting unit and a focus position adjusting step, and steps S7 and S9 to S12 implement a processing control unit and a processing step.

The means for adjusting the focus position of the laser beam irradiated on the orifice plate 5 includes z
In addition to driving the stage 31z, it may be performed by controlling an optical system through which laser light passes. However, the means for driving the z-stage 31z can easily change the focus position, and the processing accuracy of the orifice 6 can be more easily improved.

[0057]

According to the first aspect of the present invention, laser processing is performed by changing a focus position with respect to a laser processing point by using each distance data in which a measurement error is corrected based on a plurality of distance data measured for each processing unit. Therefore, laser processing with higher processing accuracy than before can be performed.

According to a second aspect of the present invention, in the laser processing apparatus according to the first aspect, the focus position can be easily changed as compared with a case where the focus position is changed by controlling the optical system. The accuracy can be further improved.

According to a third aspect of the present invention, in the laser processing apparatus according to the first or second aspect, particularly when the flatness of the processing surface is high, the influence of the irregular value of the distance data is reduced, and the processing accuracy is reduced. Can be improved. It is also effective when the machined surface is inclined.

According to a fourth aspect of the present invention, in the laser processing apparatus according to the first or second aspect, the influence of irregular values of the distance data is reduced, and variations in processing accuracy between adjacent processing units are reduced. Can be smaller. Also,
By changing the number n for which the moving average is taken, the degree of influence of the irregular value of the distance data can be changed. Furthermore, since it shows a value close to the actually measured value, it is more effective especially when the plane accuracy of the processed surface is low.

According to a fifth aspect of the present invention, in the laser processing apparatus according to any one of the first to fourth aspects, since the irregular value of the distance data is not affected, adjacent processing is performed. Variations in processing accuracy between units can be reduced. It is particularly effective when the plane accuracy of the processed surface is high.

According to a sixth aspect of the present invention, laser processing is performed by changing a focus position with respect to a laser processing point by using each distance data in which a measurement error is corrected based on a plurality of distance data measured for each processing unit. So you can
Laser processing with higher processing accuracy than before can be performed.

According to a seventh aspect of the present invention, in the laser processing method according to the sixth aspect, the focus position can be easily changed by controlling the optical system, as compared with a case where the focus position is changed. The accuracy can be further improved.

According to an eighth aspect of the present invention, in the laser processing method according to the sixth or seventh aspect, particularly when the flatness of the processing surface is high, the influence of the irregular value of the distance data is reduced, and the processing accuracy is improved. Can be improved. It is also effective when the machined surface is inclined.

According to a ninth aspect of the present invention, in the laser processing method according to the sixth or seventh aspect, the influence of the irregular value of the distance data is reduced, and the variation in the processing accuracy between adjacent processing units is reduced. Can be smaller. Also,
By changing the number n for which the moving average is taken, the degree of influence of the irregular value of the distance data can be changed. Furthermore, since it shows a value close to the actually measured value, it is more effective especially when the plane accuracy of the processed surface is low.

The invention according to claim 10 is the invention according to claims 6 to 9
In the laser processing method according to any one of the above, the irregularity of the distance data is not affected, so that a variation in processing accuracy between adjacent processing units can be reduced. It is particularly effective when the plane accuracy of the processed surface is high.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a configuration example of a conventional inkjet printer head unit.

FIG. 2 is a sectional view of an orifice plate portion of the ink jet printer head.

FIG. 3 is a block diagram showing a configuration of a laser processing apparatus according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing an expanded optical system of the laser processing apparatus.

FIG. 5 is an exploded perspective view showing a configuration of an array lens of the optical system.

FIG. 6 is a plan view of the orifice plate before laser processing.

FIG. 7 is a flowchart of control when laser processing is performed by the laser processing apparatus.

FIG. 8 shows x when laser processing is performed by the laser processing apparatus.
It is a front view explaining movement of a table.

FIG. 9 is a graph showing actual measured values of distance data in the laser processing apparatus and values obtained by correcting the actual measured values by the correction means 1 to 3;

FIG. 10 is a graph showing actual measured values of distance data in the laser processing apparatus and values obtained by correcting the actual measured values by the correction means 1 to 3;

FIG. 11 is a graph showing measured values of distance data in the laser processing apparatus and values obtained by calculating a moving average of the measured values without using the correction means 4;

FIG. 12 is a graph showing measured values of distance data in the laser processing apparatus and values obtained by calculating a moving average of the measured values using the correction means 4;

[Explanation of symbols]

 5 Work 21 Laser Processing Device 22 Laser Generation Device 26 Optical System 27 Optical System 28 Optical System 29 Optical System 30 Optical System 31x Position Moving Device 31y Position Moving Device 31z Focus Position Variable Device

Claims (10)

[Claims] 1. A laser generator for irradiating a workpiece to generate a laser for laser processing, an optical system for forming an image of the laser on a processing point of the workpiece, and a position on the workpiece for performing the laser processing. A position moving device that moves the laser, a processing control unit that performs the laser processing in each of the plurality of processing units whose positions have been changed by controlling the position moving device and the laser generating device, and a distance for each of the processing units. Measuring means for measuring a distance to the processing point by a sensor; a focus position variable device for changing a focus position of the laser with respect to the processing point; and controlling the focus position variable device to obtain the distance data after the measurement. Focus position adjusting means for adjusting the focus position for each of the processing units based on the plurality of distance data. A laser processing apparatus comprising: a correction unit configured to correct a measurement error of each distance data. 2. The laser according to claim 1, wherein the focus position changing device changes the focus position by moving a position of the work in an optical axis direction of the laser light applied to the work. Processing equipment. 3. The correction unit according to claim 1, wherein the correction unit obtains an approximate curve of the distance data after the measurement, and uses the value of the approximate curve as the distance data to perform the correction.
Or the laser processing apparatus according to 2. 4. The correction unit according to claim 1, wherein the correction unit calculates the moving average value of each distance data after the measurement, and uses the moving average value as the distance data to perform the correction. The laser processing apparatus according to item 1. 5. The correction means excludes a distance data out of a preset numerical range from each of the measured distance data, and performs the correction using the excluded distance data. The laser processing device according to claim 1. 6. A processing step of performing laser processing by imaging a laser at a processing point of a work in each of a plurality of processing units whose positions have been changed by moving the processing position on the work; A measuring step of measuring a distance to the processing point with a distance sensor for each of the processing units before the process; and each time the laser processing is performed for each of the processing units in the processing step, the distance data after the measurement. A focus position adjusting step of adjusting a focus position of the laser with respect to the processing point based on the correction step of correcting a measurement error of each distance data based on the plurality of distance data before the focus position adjusting step. Laser processing method provided. 7. The laser according to claim 6, wherein the focus position adjusting step changes the focus position by moving a position of the work in an optical axis direction of the laser light applied to the work. Processing method. 8. The method according to claim 6, wherein, in the focus position adjusting step, the correction is performed by obtaining an approximate curve of each distance data after the measurement and using a value of the approximate curve as each of the distance data. 8. The laser processing method according to 7. 9. The method according to claim 6, wherein in the focus position adjusting step, the correction is performed by obtaining a moving average value of each of the distance data after the measurement, and using each of the moving average values as the respective distance data. Or the laser processing method according to 7. 10. The correcting step excludes a distance data out of a preset numerical range from each of the measured distance data, and performs the correction using the excluded distance data. The laser processing method according to claim 6.