JPH02205289A - Laser beam machine - Google Patents

Abstract

PURPOSE:To linearly execute processing by providing a distortion correcting circuit, which corrects the intermediate part of a signal system to control an X axis optical path altering element by means of Y axis data, and corrects the intermediate part of a Y axis control signal system by means by means of X axis data, in a laser beam scanner part control system. CONSTITUTION:A DA converter 14 is connected to an analog multiplier 22, and it connects a ROM 18 through a DA converter 20 to the analog multiplier 22. The multiplier 22 is connected to a galvanodriver 16. The driver 16 is connected to a galvanomirror 6 of a Y axis optical path altering element. The distortion correcting circuit consists of ROMs 17 and 18, DA converters 19 and 20, and analog multipliers 21 and 22. That is the analog-converted product of data from a computer 10 and the data of the ROMs 17 and 18 compared with the data of the reverse axis is inputted to the galvanodrivers 15 and 16 as the main data. Thus the galvanomirror control can be linearly by adding the distortion correcting circuit.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a laser processing device that performs processing such as engraving a name plate using a laser beam, and particularly relates to a laser processing device that performs processing such as engraving on a name plate using a laser beam. The present invention relates to a laser processing apparatus that performs two-dimensional processing on a workpiece at high speed and with high precision by moving a laser beam to a desired position on a plane using a changing element, without moving the workpiece.

(Prior art) Generally, laser light has good focusing properties, and it is easy to obtain a high-energy minute spot using a condensing lens. Laser processing equipment for this purpose is becoming widespread.

By the way, methods for performing laser processing can be broadly classified based on the spatial positional relationship between the laser beam spot and the workpiece, and are those in which the position of the laser beam spot is fixed and the workpiece is moved relative to this position. There are two methods: a method in which the position of the workpiece is fixed, and a method in which the workpiece is processed by moving the laser beam to the workpiece using an optical path changing element such as a mirror.

The former has the advantage of being able to process a wide area of the workpiece, while the latter has the advantage of having a small workpiece area but fast machining speed.For this reason, it is possible to process nameplates with small areas. The latter method is generally adopted in such laser processing equipment.

That is, this type of laser processing apparatus has conventionally been configured as shown in FIG. 2, and reference numeral 1 in the figure is a laser oscillator.

A collimator 2 and a folding mirror 3 are provided at predetermined intervals on the optical path of the laser beam emitted from the laser oscillator 1, and a folding mirror 4 is further provided on the optical path of the laser beam reflected by the folding mirror 3. It is being A galvanic mirror 5 is provided on the optical path of the laser beam reflected by the folding mirror 4, and a galvanic mirror 6 is further provided on the optical path of the laser beam reflected by the galvanic mirror 5. On the optical path of the laser beam reflected by this galvanic mirror 6, an fθ lens 7 and a dichroic mirror 8 are provided at predetermined intervals, and on the optical path of the laser beam reflected by this dichroic mirror 8, a workpiece 9 is provided.

In such a laser processing device, a laser beam scanner section (laser beam driving section) is composed of a collimator 2, a folding mirror 3, a folding mirror 4, a galvanic mirror 5, a galvanic mirror 6, an fθ lens 7, and a dichroic mirror 8. . In addition, galvanic mirror 5 and galvanic mirror 6
are an X-axis mirror and a Y-axis mirror, which are so-called optical path changing elements.

The above laser beam scanner section is controlled by a laser beam scanner section control system, and this laser beam scanner section control system has conventionally been configured as shown in FIG.

That is, during operation, data is output digitally from the X-axis control board 11 and Y-axis control board 12 according to commands from the computer 10, converted to analog (voltage) by the DA converter 13.14, and input to the galvanic driver 15.16. ,
The galvanic mirror 5.6 of the laser beam scanner section is driven and operated by the galvanic driver 15.16.

However, as shown in FIG.
Due to the characteristics of the f-theta lens, if the beam passes through the periphery of the f-theta lens 7, it will not be scanned to the correct position. I end up scanning.

(Problem to be solved by the invention) Based on data such as the resolution of the galvanic driver 15 and 16,
The computer 10 calculates and controls the beam, but in reality the beam passes through the fθ lens 7. Due to the characteristics of the fθ lens, the beam passing through the center of the fθ lens 7 can be scanned almost accurately. The beam passing through the periphery of the lens 7 cannot be scanned accurately.

Therefore, when attempting to scan a square of 100 mm2, the scanning ends up in an arc shape as shown in the non-distortion corrected beam operation diagram shown in FIG.

In this invention, a distorted beam is corrected by a distortion correction circuit, and f
It is an object of the present invention to provide a laser processing device that can accurately manipulate a beam both at the center and at the periphery of a θ lens.

[Structure of the Invention] (Means for Solving the Problems) This invention incorporates Y credit data into a laser beam scanner control system in the middle of a signal system that controls an X-axis optical path changing element, and applies correction to the control system. This is a laser processing apparatus that is provided with a distortion correction circuit that takes in and corrects X-axis data in the middle of a signal system that controls a Y-axis optical path changing element.

(Function) According to the present invention, since the distortion correction circuit is provided in the laser beam scanner control system, the laser beam can be operated linearly. Also, in position control, the absolute value coordinates are accurately calculated, so it can be operated with almost no errors.
Beams can be manipulated with utmost precision.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In the laser processing apparatus of the present invention, the laser beam scanner section is configured as shown in FIG. 2 in the same manner as the conventional one, so a description of the laser beam scanner section will be omitted, and the details of the laser beam scanner control system will be omitted. I will explain.

That is, the laser beam scanner control system used in the laser processing apparatus of the present invention is configured as shown in FIG. 1, and the same parts as in the conventional example (FIG. 3) are given the same reference numerals.

That is, reference numeral 10 is a computer, and this computer 10 is connected to an X-axis control board 11 and a Y-axis control board 12. X-axis control board 11 is DA converter 1
3 and ROM 18, and the Y-axis control board 12 is connected to DA
It is connected to the converter 14 and ROM 17. The DA converter 13 is connected to an analog multiplier 21, and the ROM 17 is connected to the analog multiplier 21 via a DA converter 19. This analog multiplier 21 is connected to the galvanic driver 15, and this galvanic multiplier 21 is connected to the galvanic driver 15.
5 is connected to a galvanic mirror 5 which is an X-axis optical path changing element of a laser beam scanner section (see FIG. 2).

On the other hand, the DA converter 14 is connected to the analog multiplier 22, and the ROM 18 is connected to the analog multiplier 22 via the DA converter 20. This analog multiplier 2
2 is connected to the galvanic driver 16, and this galvanic driver 16 is connected to the Y of the laser beam scanner section (see Fig. 2).
It is connected to a galvanic mirror 6 which is an axial optical path changing element.

In the above case, ROM17.18, DA converter 19.
20 and analog multipliers 21 and 22 constitute a distortion correction circuit that is a feature of the present invention.

During operation, data is output digitally from the X-axis control board 11 and Y-axis control board 12 according to commands from the computer 10, converted to analog (voltage) by the DA converter 13.14, and converted into analog (voltage) by the analog multiplier 21. The light enters a galvanic driver 15.16 via the galvanic driver 15.16, and the galvanic mirror 5.6 of the laser beam scanner section is driven by this galvanic driver 15.16.

At this time, in the present invention, the ROM 17.
18 is converted into analog (voltage) by DA converters 13, 14, 19, 20, and both values are integrated by analog multipliers 21, 22.

That is, the analog-converted product of the data from the computer 10 and the data in the ROM 17.18 compared with the data of the linked shaft is input to the galvanic driver 15.16 as main data.

For example, if the movement is shorter than the actual value, the human power value must be increased, so ROM1
In 7.18, a numerical value from 1 to FF (hexadecimal) is manually generated, and a value higher than FF is output, and the operation is performed in between to the first actual value.

Even when the robot operates over a distance longer than the actual value, a value greater than 1 is output so as to similarly reduce the input value.

In other words, when scanning the X-axis, take in the Y-axis data and calculate the ratio of the command value and actual value of the X coordinate at that time.
M17, the value and the X-axis data are DA-converted, and the integrated value is input to the galvanic driver 15.

And if you want to scan larger than the instruction value,
Since the command value must be made smaller, a value that makes the ratio of the command value to the actual value be 1 is stored in the ROM 17.
It is integrated and input to the galvanic driver 15.

When scanning a value smaller than the command value, the command value is increased, so the ratio of 1 or more is integrated and inputted to the galvanic driver 15.

As mentioned above, in the normal case where the beam passes through the fθ lens 7, even if a command to draw a straight line is input as shown in FIG. 4, the beam will move in a curved manner. However, in the present invention, by passing the beam through a distortion correction circuit, the absolute values of the operating coordinates are accurate, and the beam can be manipulated linearly.

By the way, if a straight line is drawn without a distortion correction circuit, there will be an error of about 0.5 mm (500 μm) at maximum, but by adding a distortion correction circuit, the error becomes about 50 μm. In normal laser control, the beam diameter is about 40 to 60 μm, so there is no problem with 50 μm.

Also, the actual value of 50 μm was obtained by solving the value input to ROM17.18 from a cubic equation, but the value obtained by sampling at 10 points and solving the 100th order equation was stored in ROM17.18. When input, the error should be less than 10 μm.

If the circuit itself remains as it is and the chains input to the ROMs 17 and 18 are made as accurate as possible, the actual scanning values will also be as accurate as possible.

[Effect of the invention] According to this invention, the following excellent effects can be obtained.

That is, when a laser beam is operated through an fθ lens and controlled by a galvanic mirror, the laser beam is operated not in a straight line but in a curve, but by adding a distortion correction circuit, the laser beam can be operated in a straight line.

In addition, position control can be operated with almost no errors because the absolute value coordinates are accurately calculated.

Then, the more accurate the values input to the ROM are, the more accurate the beam operation can be made to the limit, while the distortion correction circuit remains unchanged.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a block diagram showing a laser beam scanner control system in a laser processing apparatus according to an embodiment of the present invention;
Fig. 2 is a block diagram showing a laser beam scanner section in a conventional laser processing apparatus and the present invention, Fig. 3 is a block diagram showing a conventional laser beam scanner control system, and Fig. 4 shows beam operation without distortion correction. It is an explanatory diagram. DESCRIPTION OF SYMBOLS 1... Laser oscillator, 5... Galvanor mirror (X-axis optical path changing element), 6... Galva mirror (7-wheel optical path changing element) 9... Workpiece, 10... Computer, 1
1...X-axis control board, 12...Y-axis control board,
13.14.19.20...DA converter, 15.
16... Galva driver, 17.18... ROM. 21.22...Analog multiplier.

Claims (1)

[Scope of Claims] The above laser oscillator comprises a laser oscillator, a laser beam scanner section having an X-axis optical path changing element and a Y-axis optical path changing element, and a laser beam scanner section control system that controls the laser beam scanner section. In the laser processing apparatus, the laser beam emitted from the laser beam is manipulated by the X-axis optical path changing element and the Y-axis optical path changing element, and the laser beam is focused on the processing surface of the workpiece for processing. , Y-axis data is taken in and corrected in the middle of the signal system that controls the X-axis optical path changing element, and X-axis data is taken in the middle of the signal system that controls the Y-axis optical path changing element. A laser processing device characterized by being provided with a distortion correction circuit that performs correction.