JP3063677B2 - Laser processing apparatus and laser processing method - Google Patents

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 a laser processing method, and more particularly to a laser processing apparatus and a laser processing method for a laser trimmer, a laser marker, and the like comprising a laser oscillator, an optical scanning unit, and an observation optical unit.

[0002]

2. Description of the Related Art Generally, in a laser processing apparatus such as a laser trimmer, a laser marker, etc., comprising a laser oscillator, an optical scanning section, and an observation optical section, a predetermined position on a workpiece is irradiated with laser light and processed. An image recognizing device is used to recognize that the laser processing position has been corrected by the image recognizing device based on the positional relationship between the workpiece and the observation system.

[0003] Such an image recognition device (image processing device)
A conventional laser processing apparatus provided with the above is disclosed, for example, in Japanese Patent Application Laid-Open Nos. 5-177374 and 8-243773.

[0004] A laser processing apparatus disclosed in Japanese Patent Application Laid-Open No. 5-177374 (hereinafter referred to as a first prior art) is disclosed in
A laser processing apparatus that performs laser processing by condensing laser light emitted from a laser oscillator with a condenser lens and irradiating the laser beam to a workpiece, and photographs an area near a laser irradiation surface of the workpiece through the condenser lens. A photographing unit, an image processing device that captures and stores the captured image and performs image processing, a monitor that displays the storage and the stored image of the image processing device and the processing result, and a laser oscillator according to the processing result of the image processing device. Means for performing control.

According to the first prior art, when observing a processing portion of a laser processing apparatus, not only a captured image is displayed but also an image processing result is displayed, thereby improving processing evaluation. ing.

[0006] A laser processing apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 8-243773 (hereinafter referred to as a second prior art)
A laser processing apparatus that performs laser processing by moving at least one of a work table equipped with an emission optical system and a work so that an optical axis of a laser beam emitted from the emission optical system moves on a workpiece to be processed. A CCD for photographing an area in a predetermined range including a line to be processed of a work
A camera is provided in the emission optical system, and at least one processing line approximated to the processing line by performing a predetermined process on an image including the processing line of the CCD camera with movement of the emission optical system or the work table. An image processing unit for detecting the position difference between a reference point set in advance in the image of the CCD camera and serving as the optical axis of the laser beam, and a closest point on the detected processing line. A control unit that controls a driving unit of the emission optical system or the work table so as to correct the displacement.

According to the second prior art, the subsequent processing is performed by using the obtained movement data of the emission optical system or the work table as teaching data, and the detected processed line is transferred to a CCD through a drawing device and an image superposition device. When a plurality of processing lines are displayed so as to be superimposed on the image of the camera, one of the processing lines is selected by the selector.

[0008]

In the first prior art,
The positional relationship between the observation optical unit and the workpiece is obtained by the image processing apparatus to perform the position correction. However, the position correction is performed on the assumption that the laser focused spot does not deviate from the observation optical unit. In addition, for example, by irradiating a laser condensed spot on a mechanically positioned optical sensor and detecting a relative displacement between the optical sensor and the laser condensed spot, the amount of displacement of the laser condensed spot can be corrected. There is also a method to increase accuracy.

However, in such a position correction method, the positional relationship between the workpiece and the laser condensed spot is indirectly obtained, and is not directly obtained, so that highly accurate position correction is difficult. .

In the second prior art, a position of a line to be processed displayed on a screen is obtained by image processing, and a relative error between the position and a laser processing position on the screen (in most cases, the center position of the screen). Ask for. In the case of welding, a boundary portion to be welded is a line to be processed, and in the case of cutting, a marking line or the like is drawn at a position to be cut and this is a line to be processed.

However, it is assumed that the processing position does not deviate from the image (it is always at the center), the deviation amount between the image center position and the workpiece is obtained by image processing, and the position is corrected. When the optical axis of the processing optical system is shifted and the laser processing position is deviated from the center of the screen, there is a disadvantage that it is difficult to correct the laser processing position.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a laser processing apparatus and a laser processing apparatus capable of performing high-precision laser processing by directly comparing laser processing positions on a workpiece. The aim is to provide a method.

[0013]

SUMMARY OF THE INVENTION A laser processing apparatus according to the present invention is a laser processing apparatus for condensing a laser beam emitted from a laser oscillator and irradiating a laser beam to a workpiece, thereby performing processing. A first photographing means for photographing a processing target range of the workpiece, a second photographing means for photographing the trajectory of the laser beam on the workpiece, and image data of the processing target range taken in by the first photographing means and a second photographing means. Control means for comparing the trajectory data of the laser light captured by the photographing means, calculating the amount of displacement of the laser processing position with respect to the workpiece, and correcting the laser processing position. Things.

According to the present invention, the first photographing means
The image data of the processing range is captured before processing, the trajectory data of the laser light on the workpiece is captured during processing by the second photographing means, and the image data of the processing range and the trajectory data of the laser light are controlled by the control means. To calculate the positional deviation of the laser processing position with respect to the workpiece, and correct the laser processing position based on the calculation result of the positional deviation, so that the laser processing position with respect to the workpiece is directly compared. Will do.

Preferably, the laser processing apparatus of the present invention further comprises means for preventing the reflected light of the laser light from reaching the first photographing means.

A laser processing apparatus according to another embodiment of the present invention is a laser processing apparatus for condensing a laser beam emitted from a laser oscillator and irradiating the laser beam to a workpiece to perform processing. A photographing means for photographing the trajectory of the laser light on the workpiece while photographing the processing target area of the workpiece, and a laser light reflected optical path between the photographing means and the workpiece, so that only the laser light is emitted. Laser light transmitting means for transmitting, means for removing the laser light transmitting means from the reflection optical path when imaging the processing target area of the workpiece before processing, image data of the processing target area taken by the imaging means and laser Control means for comparing the trajectory data of the light with the laser processing position, calculating a positional shift amount of the laser processing position with respect to the workpiece, and correcting the laser processing position.

According to the laser processing apparatus of another aspect of the present invention, the movement of the laser beam transmitting means allows one photographing means to operate,
The image data of the processing target range and the trajectory data of the laser beam can be captured.

The photographing means may include a zoom means for changing a photographing magnification in accordance with a positioning accuracy of the workpiece. Further, an illumination means for illuminating the workpiece may be provided.

The laser processing method of the present invention is a laser processing method in which laser light emitted from a laser oscillator is condensed and irradiated on a workpiece to perform processing. (1) Before processing, the processing of the workpiece is performed. A step of photographing the processing target range and obtaining image data of the processing target range; (2) a step of photographing the trajectory of the laser light on the workpiece to obtain the trajectory data of the laser light; and (3) a processing target range. Comparing the image data of the laser beam with the locus data of the laser beam, calculating the amount of displacement of the laser processing position with respect to the workpiece, and correcting the laser processing position. ) In this order.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a laser processing apparatus according to the first embodiment.

As shown in FIG. 1, a laser processing apparatus according to the first embodiment comprises a laser oscillator 1 for emitting a laser beam L.
An optical scanning unit 2 that controls the traveling direction of the laser light L, a beam splitter 3 that sends the laser light L to the workpiece W and sends visible light or laser reflected light in the processing target range to the photographing side, An objective lens 4 for condensing a laser beam L on a workpiece W, a first CCD camera 5 for capturing an area to be processed before processing, and a second CCD for capturing a locus of a laser beam spot on the workpiece W A camera 6 and image data of a processing target area captured by the first CCD camera 5;
A control unit 7 for comparing the trajectory data of the laser beam spot captured by the CCD camera 6 and calculating the amount of displacement of the laser processing position with respect to the workpiece W.

The workpiece W is placed on a work table (not shown), and is subjected to, for example, welding,
It is cut and opened.

As the light scanning unit 2, for example, a galvanometer is used.

The beam splitter 3 uses a dichroic mirror having a high reflectance for the laser light L and a low reflectance for the visible light for observation.

The control unit 7 controls the operation of the optical scanning unit 2 and the work table on which the workpiece W is mounted based on the calculation result of the amount of displacement of the laser processing position with respect to the workpiece W, and performs laser processing. The position (the position of the focused spot of the laser beam L) is corrected.

The laser processing apparatus according to the first embodiment also has
An imaging lens 8 arranged above the beam splitter 3 for forming an image on the first CCD camera 5 and the second CCD camera 6; and an imaging lens 8 arranged below the first CCD camera 5 so that the laser reflected light reaches the first CCD camera 5. And a reflection mirror 10 for transmitting the laser reflected light to the second CCD camera 6 side, and a high transmittance for the laser reflected light. , Filter 1 showing low transmittance for other light
And 1. When the intensity of the laser light L entering the second CCD camera 6 is high, it is preferable to additionally provide an attenuation filter for attenuating the laser light L.

Next, the operation of the laser processing apparatus according to the first embodiment will be described. First, before processing by the laser beam L, observation of the processing target range is performed. At this time, the shutter 9 is in an open state, and light in a processing target range on the surface of the workpiece W is transmitted through the objective lens 4 and the imaging lens 8.
Since the light reaches the first CCD camera 5, the first CCD camera 5 captures an image of the processing target range. FIG. 2 (A)
5 shows an image of a processing target range (a range to be processed collectively). The image data of the processing target range captured by the first CCD camera 5 is sent to the control unit 7.

At the time of processing, the laser beam L emitted by the laser oscillator 1 is controlled in the traveling direction by the optical scanning unit 2, reflected by the beam splitter 3, and reflected by the objective lens 4.
Is focused on the workpiece W surface.

The spot locus of the laser beam L on the surface of the workpiece W is photographed by the second CCD camera 6. that time,
Since the shutter 9 is in the closed state, the laser reflected light is blocked by the shutter 9 and does not reach the first CCD camera 5.

The condensing spot of the laser beam L is moved in accordance with a predetermined pattern within the processing range, and the trajectory of the laser beam L is maintained until the pattern scanning is completed.
Is captured and captured as trajectory data.
FIG. 2B shows an image of the trajectory of the laser light L. 2nd C
The locus data of the laser light L captured by the CD camera 6 is sent to the control unit 7.

The control unit 7 controls the image data of the processing target range captured by the first CCD camera 5 and the second CCD
The trajectory data of the laser beam spot captured by the camera 6 is stored and compared with each other, and the workpiece W
Of the laser processing position with respect to. FIG.
(C) shows an image obtained by combining the image of the processing target range and the image of the trajectory of the laser beam L. The controller 7 stores the laser trajectory taken in at the time of the first alignment and the image data of the processing target range. The positional deviation between the processing position and the condensed spot of the laser beam L is calculated by comparing with this data. Is done.

The control unit 7 controls the operation of the optical scanning unit 2 and the work table on which the workpiece W is placed based on the calculation result of the amount of displacement of the laser processing position with respect to the workpiece W, and performs laser processing. The position (the position of the focused spot of the laser beam L) is corrected.

According to the laser processing apparatus of the first embodiment, the image data of the processing target area captured by the first CCD camera 5 is compared with the locus data of the laser light L captured by the second CCD camera 6. Then, the amount of displacement of the laser processing position with respect to the workpiece W is calculated, and the laser processing position is corrected. Therefore, the laser processing position with respect to the workpiece W is directly compared, and the laser light L and the laser processing position are compared. The object W can be positioned with high accuracy, and high-precision laser processing can be performed.

Further, since only the trajectory data of the laser beam L is fetched, the process of extracting the information of the laser trajectory from the image information becomes unnecessary, and the calculation processing in the control unit 7 can be sped up.

FIG. 3 is a block diagram showing a laser processing apparatus according to the second embodiment. As shown in FIG. 3, the laser processing apparatus according to the second embodiment includes a CCD camera 20 that captures image data of a processing target range and locus data of a laser beam L; , A filter 21 having a high transmittance only with respect to the laser reflected light, a zoom lens 22 attached to the CCD camera 20, a light source 23 for illuminating a processing target area of the workpiece W, Fθ lens 24 disposed between the scanning unit 2 and the beam splitter 3.

The filter 21 is deviated from the optical path when the laser beam L is not oscillating while observing the processing target range, and is inserted into the optical path when the trajectory of the laser light L is captured. The movement of the filter 21 is performed manually or by a moving device (not shown). When the intensity of the laser light L entering the CCD camera 20 is high, it is preferable to additionally provide an attenuation filter for attenuating the laser light L.

The zoom lens 22 is operated so as to secure an observation (photographing) magnification in accordance with the alignment accuracy required for positioning, and a required recognition resolution can be obtained.

In addition, the laser oscillator 1, the optical scanning unit 2, the beam splitter 3, the imaging lens 8, and the control unit 7 are the same as those in the first embodiment.

In the laser processing apparatus according to the first embodiment,
Although two CCD cameras 5 and 6 were required, in the laser processing apparatus according to the second embodiment, the image data of the processing target area and the laser L trajectory data can be captured.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the technical matters described in the claims. For example, CC
A monitor that displays an image of the processing target range captured by the D camera or an image of the locus of the laser beam L may be connected to the control unit 7.

[0041]

According to the present invention, image data of a range to be processed is captured by a photographing unit before processing, and locus data of a laser beam on a workpiece during processing is captured by a photographing unit. Since the image data of the range is compared with the trajectory data of the laser light, the amount of positional deviation of the laser processing position with respect to the workpiece is calculated, and the laser processing position is corrected based on the calculation result of the positional deviation amount. By directly comparing the laser processing position with respect to the workpiece, the laser beam and the workpiece can be positioned with high precision, and high-precision laser processing becomes possible.

Further, since only the trajectory data of the laser beam is taken in, the process of extracting the information of the laser trajectory from the image information becomes unnecessary, and the speed of the arithmetic processing in the control unit can be increased.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a laser processing apparatus according to a first embodiment.

FIG. 2A shows an image of a processing target range, and FIG.
FIG. 3C is an explanatory diagram showing an image of a locus of laser light, and FIG. 4C is an explanatory diagram showing an image obtained by combining the image of the processing target range and the image of the locus of laser light.

FIG. 3 is a configuration diagram illustrating a laser processing apparatus according to a second embodiment.

[Explanation of symbols]

 L: Laser light W: Workpiece 1: Laser oscillator 2: Optical scanning unit 3: Beam splitter 4: Objective lens 5: First CCD camera 6: Second CCD camera 7: Control unit 8: Imaging lens 9: Shutter 10: Reflecting mirror 11: Filter 20: CCD camera 21: Filter 22: Zoom lens 23: Light source 24: fθ lens

Claims (6)

(57) [Claims] A laser oscillator for emitting a laser beam; and an optical scanning unit for controlling a traveling direction of the laser beam emitted from the laser oscillator. The laser beam controlled by the optical scanning unit is collected. A laser processing apparatus for irradiating a workpiece by irradiating the workpiece with light, comprising: a first imaging unit configured to capture a processing target range of the workpiece before processing; and a laser beam controlled by the optical scanning unit. A second photographing means for photographing a trajectory of irradiation on the workpiece; image data of a processing target range captured by the first photographing means; and trajectory data of laser light captured by the second photographing means. A laser processing apparatus, comprising: control means for comparing the position of the laser processing position with respect to the workpiece, and correcting the laser processing position. 2. The laser processing apparatus according to claim 1, further comprising means for preventing reflected light of the laser light from reaching the first photographing means. 3. A laser processing apparatus for condensing a laser beam emitted from a laser oscillator and irradiating a workpiece with the laser beam for processing, wherein an image of a processing target range of the workpiece is taken before processing.
A photographing means for photographing the trajectory of the laser light on the workpiece, a laser light transmitting means disposed on a reflection optical path of the laser light between the photographing means and the workpiece, and transmitting only the laser light; Means for removing the laser light transmitting means from the reflected light path when photographing the processing target range of the workpiece before processing; and image data and laser beam locus data of the processing target range taken in by the photographing means. And a control unit that calculates a positional shift amount of the laser processing position with respect to the workpiece and corrects the laser processing position. 4. The laser processing apparatus according to claim 3, wherein said photographing means has zoom means for changing a photographing magnification. 5. The laser processing apparatus according to claim 3, further comprising illumination means for illuminating the workpiece. 6. A laser processing method in which a traveling direction of a laser beam emitted from a laser oscillator is controlled by an optical scanning unit, and the controlled laser beam is condensed and irradiated on a workpiece to perform processing. (1) photographing a processing target range of the workpiece before processing;
Obtaining image data of a processing target range; and (2) capturing a trajectory of irradiation of the workpiece by the laser light controlled by the optical scanning unit to obtain trajectory data of the laser light; (1) comparing the image data of the processing target range with the trajectory data of the laser beam, calculating the amount of displacement of the laser processing position with respect to the workpiece, and correcting the laser processing position. ) To (3) in that order.