JPH08118055A - Coaxial observation device in laser machining - Google Patents

Abstract

PURPOSE: To provide an observation device which eliminates waste time accompanied by an observation and errors related to mechanical operations, in a device which is installed in a nonvisible-laser beam machine in order to observe the irradiated position of a laser beam. CONSTITUTION: A visible laser beam 13 from a visible-laser generator 17 is transmitted to an object 11 to be machined through a beam compiler 25, on the same axis as the optical path axis of a nonvisible-laser beam 19 for machining. In addition, the object 11 is irradiated with the light 27 provided near a machining lens 9. Then, the reflected light from the position irradiated with the visible-laser beam and the reflected light from the object irradiated with the light are taken in a CCD camera 29 through the beam compiler 25. The image thus taken in is projected on a monitor 35 and processed with a personal computer 37 by the image processing technique with deviation from a target irradiation position calculated. On the basis of a signal for correcting this deviation, an XY table 13 on which the object to be machined is placed is controlled through an NC controller 39, and the deviation is thereby corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an observing device which is provided in a laser machining apparatus for machining with a laser beam and observes the irradiation position of the laser beam on a workpiece.

[0002]

2. Description of the Related Art In recent years, laser technology has been used in various industrial fields. There are various types of lasers, such as gas lasers, solid-state lasers, and semiconductor lasers, depending on the mechanism of laser oscillation. There are various industrial fields that are used, such as a field that uses a processing-thermal process for cutting or punching a material such as metal, and a field that uses a photochemical reaction process. In particular, a CO ₂ laser, which is one of the gas lasers, has a large output and a high efficiency, and is widely used in the laser processing field.

An example of this CO ₂ laser processing apparatus is shown in FIG. The laser beam 3 output from the laser oscillator 1 passes through the optical path accordingly, reaches the mask 5, obtains a pattern by the mask 5, bends the optical path by the total reflection mirror 7, passes through the processing lens 9, and is processed. An image is formed on the surface of the object 11. The processing object 11 is placed on the XY table 13 and processed.

In the past, this CO ₂ laser was unsuitable for fine processing. For example, the processing for film-shaped plastic with a thickness of less than several hundreds of micrometers is
Burning, scorching, who, distortion, etc. were obstacles and did not go well. However, as a result of progress in development in recent years, laser light itself has become capable of such fine processing.

However, since such laser light is generally invisible light and the processing is minute, it is not possible to directly observe the irradiation position on the object to be processed with the naked eye. If it cannot be observed, the deviation of the irradiation position cannot be corrected. Therefore, as a conventional device for observing the irradiation position of the invisible laser light on the object to be processed, a CCD camera provided with a light 10 as shown in FIG. There is a device that captures the image in 12 and enlarges the captured image on the monitor 14 to observe it. This C
The CD camera 12 adopts an offset method in which the CD camera 12 can move relative to each other so as not to interfere with the station head provided with the processing lens 9 located near the processing target 11. Alternatively, the CCD camera 12 and the station head do not move, and the XY table 1 on which the workpiece 11 is placed is placed.
An offset method is used in which 3 is moved to the bottom of the CCD camera 12. Then, after observing the irradiation mark, the position is returned by moving in the opposite direction, and the deviation of the irradiation position is corrected.

[0006]

However, in the conventional offset type observation apparatus, it takes a long time to move the CCD camera 12 and the station head or the XY table 13 on which the workpiece 11 is placed, and Detection and numerical data processing accompanying these movements took time. The loss time caused by this is, for example, a few seconds, but becomes a large loss when a large number of processing objects are continuously processed.

Further, an error associated with the mechanical operation, such as an error due to the backlash of the moving mechanism of the moving mechanism necessary for the movement, occurs. Such a problem occurs not only in the case of processing by CO2 laser but also in the case of processing by other invisible laser light. The present invention
The present invention has been made in order to solve the above problems, and an object thereof is to provide an observation device that does not have an error due to a loss time or machine operation.

[0008]

In order to achieve the above object, the invention of claim 1 is provided in a laser processing apparatus for guiding an invisible laser beam from a laser oscillator to an object to be processed, A coaxial observation device in laser processing for observing an irradiation position of an invisible laser light on a processing object, wherein the visible laser light is sent to the processing object coaxially with the optical path axis of the invisible laser light, It is characterized in that reflected light of laser light is taken into a CCD camera and the taken image is displayed on a monitor.

According to a second aspect of the present invention, there is provided a laser processing device for guiding and processing the invisible laser light from the laser oscillator to the object to be processed through the processing lens. A coaxial observation device in laser processing for observing an irradiation position, wherein a visible laser oscillator for outputting a visible laser light and an output visible laser light are sent to an object to be processed coaxially with an optical path axis of the invisible laser light. Therefore, a beam combiner having a property of obliquely provided on the optical path axis of the invisible laser light and transmitting the visible laser light and transmitting the invisible laser light, and a light provided near the processing lens and illuminating the object to be processed. A CCD that takes in the reflected light from the irradiation position of the processing object by the visible laser light and the reflected light from the processing object illuminated by the light via the beam combiner. A half mirror for branching the optical path of the image toward the CCD camera and the optical path of the visible laser light from the visible laser oscillator; and a monitor for displaying an image captured by the CCD camera. .

According to a third aspect of the present invention, there is further provided an arithmetic processing means for processing the captured image by an image processing technique to calculate a deviation from a target irradiation position and outputting a deviation correction signal, and based on the deviation correction signal. And a control unit that corrects the deviation by controlling the XY table on which the processing target is placed.

According to a fourth aspect of the present invention, the laser processing apparatus is a CO ₂ laser apparatus for fine processing.

The invention of claim 5 is characterized in that the object to be machined is an FPC, a molded product or the like which requires a machining position accuracy.

[0013]

According to the invention of claim 1, the visible laser light is sent to the object to be processed coaxially with the optical path axis of the invisible laser light to be processed, and the reflected light of the visible laser light from the object to be processed is C.
Capture it to a CD camera and display the captured image on the monitor.

According to the second aspect of the present invention, the visible laser light output from the visible laser oscillator is sent to the object to be processed through the beam combiner coaxially with the optical path axis of the invisible laser light to be processed. This visible laser light is reflected from the irradiation position of the object to be processed. A light provided near the processing lens illuminates the object to be processed. Then, the reflected light from the irradiation position of the visible laser light and the reflected light from the processing object illuminated by the light are taken into the CCD camera via the beam combiner. The captured image is displayed on the monitor.

According to the third aspect of the invention, the captured image is further processed by the image processing technique to calculate the deviation from the target irradiation position. Based on this deviation correction signal, the XY table on which the object to be processed is placed is controlled to correct the deviation.

According to the invention of claim 4, the laser processing apparatus is a CO ₂ laser apparatus for fine processing, and accurate fine processing can be performed by observing the irradiation position.

According to the fifth aspect of the invention, the object to be machined is an FPC, a molded product or the like which requires a machining position accuracy, and the machining can be carried out at an accurate position and the requirement is satisfied.

[0018]

Embodiment One embodiment of the present invention is shown in FIGS. The laser processing apparatus of this embodiment is a typical impact type TEACO ₂ laser apparatus which performs fine processing by a so-called mask image method with an invisible laser light in the ultraviolet region.

Laser light 3 output from the laser oscillator 1
Goes to the mask 5 through the optical path accordingly. Mask 5
The laser light 3 having the pattern obtained in (1) has its optical path bent 90 degrees by the total reflection mirror 7 made of copper as a base, passes through the processing lens 9, and forms an image on the surface of the processing target 11.
The object 11 to be processed is placed on the XY table 13, moved in the X direction or the Y direction, laser light irradiation is performed with a predetermined oscillation time, frequency, and number of shots, and processing such as desired drilling or groove formation is performed. Done.

This laser processing apparatus is provided with a coaxial observation device 15 for observing the irradiation position of laser light. In addition to the laser oscillator 1, a visible laser oscillator 17 that outputs visible laser light (for example, HeNe laser light) is provided. In order to send the output visible laser light to the processing target 11 coaxially with the optical path 19 axis of the invisible laser light,
A total reflection mirror 21 and a half mirror 23 are provided, and a beam combiner 25 is provided at an angle of 45 degrees to the optical path 19 axis of the invisible laser light. This beam combiner 2
5 has the property of transmitting invisible laser light and reflecting visible laser light.

A ring light 27 for illuminating the object 11 to be processed is provided around the lower end of the processing lens 9.
Further, the reflected light from the irradiation position of the object to be processed 11 by the visible laser light and the reflected light from the object to be processed 11 illuminated by the ring light 27 are reflected by the beam combiner 25 and transmitted through the half mirror 23. A CCD camera 29 for capturing is provided. This half mirror 23
Is for branching an optical path 31 of reflected light toward the CCD camera 29 and an optical path 33 of visible laser light from the visible laser oscillator. A monitor 35 that captures the captured image is connected to the CCD camera 29.

A personal computer 37 is connected to the monitor 35. The personal computer 37 serves as an arithmetic processing unit that processes the captured image of the irradiation position by an image processing technique, calculates a deviation from the target irradiation position, and outputs a deviation correction signal. An NC controller 39 is connected to the personal computer 37 as a control unit that controls the XY table 13 on which the workpiece 11 is placed based on the deviation correction signal to correct the deviation. The XY table 13 is connected to the NC control device 39, and the XY table 13 on which the workpiece 11 is placed is moved in the X direction or the Y direction.

The operation of this embodiment will be described below with reference to FIGS. The visible laser light output from the visible laser oscillator 17 bends the optical path at 90 degrees by the total reflection mirror 21, further bends the optical path at the opposite side by 90 degrees by the half mirror 23, and then through the beam combiner 25. Optical path 1 of invisible laser light for processing by bending the optical path by 90 degrees
The 9-axis and the optical path 33 are coaxial. Then, it is sent to the object 11 to be processed through the processing lens 9 and irradiated. This visible laser light is reflected from the irradiation position of the processing object 11. A ring light 27 provided near the processing lens 9 illuminates the entire processing target 11.

Then, the reflected light from the irradiation position of the visible laser light and the reflected light from the processing object 11 illuminated by the ring light 27 bends the optical path by 90 degrees through the beam combiner 25, and the CCD camera Is taken into. The captured image is displayed on the monitor 35.

Furthermore, the captured image is displayed on the personal computer 37.
Performs processing by image processing technology to calculate the deviation between the irradiation position of visible laser light and the target irradiation position. Based on this deviation correction signal, the NC control device 35 controls the XY table 13 on which the workpiece 11 is placed to move in the X and Y directions to correct the deviation.

There are various image processing techniques that can be used at this time, and any one may be used if possible.
In this embodiment, as an example, a method called a pixel coefficient method in a window frame is adopted for description. That is, as shown in FIG.
A frame 4 having a cross indicating a target irradiation position 43 is displayed on the screen on which the cross-sectional image 41 of the processing object 11 and the laser light is displayed.
5 are provided. When the cross-sectional image 41 of the laser light is near the target irradiation position 43, the cross-sectional image 41 and the frame 45 having a cross form eight regions A to H.
Of these regions, B, C, F, and G receive laser light and become white, and A, D, E, and H appear black. As a result, 8
Areas A (black), B (white), C (white), D (black), E
(Black), F (white), G (white), and H (black) are formed.

Then, as shown in FIG. 3, the numbers of pixels a, b, c, d, e, f, g and h in the eight areas are calculated (S
1). If the cross-sectional image 41 coincides with the target irradiation position 43 in the horizontal direction, for example, a and d are the same and b and c are the same number. Or
The numbers e and h are the same, and the numbers f and g are the same. Similarly, if they match in the vertical direction, a and e are the same number, and b and f are the same number. Or d and h,
c and g are the same number. Therefore, it suffices to control and correct them so that they have the same number. Therefore, F1 is calculated by the following formula.
Alternatively, F2, F3 or F4 is calculated (S2).

[0028]

[Equation 1]

[0029]

[Equation 2]

[0030]

(Equation 3)

[0031]

[Equation 4]

A signal based on these F1 or F2, F3 or F4 is output as a deviation correction signal. The NC control device 39 operates based on this deviation correction signal. First, F
By using the XY table 13 in the direction in which 1 or F2 approaches 0, correction is performed in the horizontal direction (for example, the X-axis direction) of the screen in FIG. 2 (S6). When F1 or F2 is sufficiently close to 0 (S7), the horizontal correction is finished (S8).
Next, in the direction in which F3 or F4 approaches 0, correction is performed in the vertical direction (for example, the Y-axis direction) of the screen of FIG. 2 using the XY table 13 (S9). If F1 or F2 is sufficiently close to 0 (S10), the vertical correction is finished (S11). In this way, the deviation is corrected.

Further, when the cross-sectional image 41 of the laser beam is not near the target irradiation position 43, the cross-sectional image 41 and the frame 45 having a cross do not form eight regions.
Prepare another method as a supplement. That is, when eight areas are not formed, the number of pixels of at least one of the areas B, C, F, and G becomes 0 (S3). In that case, the vector V of the following equation is considered and the magnitude of the vector V is calculated (S
4).

[0034]

(Equation 5)

[0035]

(Equation 6)

Then, correction is performed in the direction in which the magnitude of V becomes 0, that is, in the direction in which it decreases (S5). By this auxiliary method, after the cross-sectional image 45 comes to be located near the target irradiation position 47, the methods (S6) to (S1) are performed.
The correction is performed according to 1) to correct the deviation.

When the deviation is corrected in this way and the center of the cross-sectional image 41 of the visible laser light coincides with the target irradiation position 43, the output of the visible laser light from the visible laser oscillator 17 is stopped, and immediately after that, the laser is immediately emitted. The invisible laser light 3 output from the oscillator 1 passes through a predetermined optical path, passes through the processing lens 9, and forms an image on the surface of the processing target 11. The processing object 11 is moved in the X direction or the Y direction by the XY table 13, and processing such as desired drilling and groove formation is performed.

As described above, according to this embodiment, the switching between the visible laser light and the invisible laser light can be performed immediately, so that the conventional CCD camera 29 is moved, the processing lens 9 and the ring light 27 are provided. There is no need to move the station head or the XY table on which the workpiece is placed. Therefore, detection and numerical data processing associated with these movements do not take time. Further, it is not necessary to provide a moving mechanism necessary for moving, and errors due to mechanical operation do not occur.

Further, since the correction work is performed while observing the cross-sectional image of the laser light on the monitor 35, it is sufficient to set the limit value of the deviation amount, that is, how close F1 or F2, F3 or F4 is to "0". Settings such as whether to determine that the value is close to "0" can be set for each mask 5, that is, for each processing condition.

Further, the coaxial observation device 15 of this embodiment is
Even while the laser processing apparatus is operating, the laser processing apparatus can be continuously operated and the deviation correction can be continuously performed.

Further, the laser processing apparatus of this embodiment is a CO ₂ laser apparatus for fine processing, and by observing the irradiation position, the application can be further expanded and accurate fine processing can be performed. That is, conventionally, microfabrication using a CO ₂ laser, for example, microfabrication for film-shaped plastic having a thickness of several hundreds of micrometers or less, has not been successful due to burns, charring, sagging, distortion, and the like. However, as a result of the progress of development in recent years, such fine processing has become possible. However, because of the invisible laser light, observation of the irradiation position does not work well, and in particular, the processing origin, which is the irradiation position at the start of processing, can be automatically set with the accuracy of the hundreds or thousands position. There wasn't. Therefore, when the object to be processed is an FPC that requires processing position accuracy, a molded product that constitutes a precision industrial product such as a camera or a clock, or a rubber roller that is used for a printer or a copying machine and whose surface is graved. Can't be micromachined,
The applications for microfabrication were limited. However, according to this embodiment, the cross-sectional image of the visible laser light is freely magnified and observed by the monitor 35, the machining origin is easily set, and the requirement of machining position accuracy can be sufficiently satisfied. .

In the above embodiment, as shown in FIG. 2, not only the cross-sectional image 41 of the laser beam but also the contour of the object 11 to be processed is shown on the screen. Therefore, the frame 45 having a cross indicating the target irradiation position 43 can be easily provided based on this contour. However, if the contour of the object 11 to be machined is not displayed on the screen, it is advisable to attach reference marks such as recognition marks to the object 11 and jigs at a plurality of locations.

Further, in the case of processing the processing object 11 which requires a higher processing position accuracy, the XY table 1 is used.
If an item having an angle correction function in 3 is used, processing is easy.

Further, in the above embodiments, the two-dimensional processing by the mask image method for processing the object to be processed on the XY table 13 using the mask 5 is carried out, but in other embodiments, the laser marking is also performed. It can also be applied to 3D robots.

Further, in the above embodiments, the reflected visible laser light travels through the beam combiner 25 to the optical path 9
Although it is bent by 0 degree and taken into the CCD camera 29, it may be bent by another angle instead of 90 degrees in other embodiments. As a result, the CCD camera 29 can be obliquely attached to the workpiece 11.

[0046]

As described above, the first and second aspects of the present invention are as follows.
According to the invention of 3, 4, or 5, the visible laser light is sent to the object to be processed coaxially with the optical path axis of the invisible laser light to be processed, and the reflected light of the visible laser light from the object is processed. The irradiation position of the visible laser light, and hence the irradiation position of the invisible laser light, can be indirectly observed by capturing the image in the CCD camera and displaying the captured image on the monitor. Since the visible laser light and the invisible laser light can be switched immediately, or because the observation can be continued while the processing is performed without switching, the conventional movement of the CCD camera is not necessary at all. Therefore, detection and numerical data processing accompanying these movements do not take time and no loss time occurs. Further, it is not necessary to provide a moving mechanism necessary for moving, and errors due to mechanical operation do not occur.

According to the second aspect of the present invention, the light provided near the processing lens illuminates the object to be processed, so that the image of the object to be processed can be captured clearly and the observation becomes easy. . Then, the conventional movement of the CCD camera, movement of the station head equipped with the processing lens and light, or movement of the XY table on which the processing target is placed is not necessary at all.

According to the third aspect of the present invention, the captured image of the irradiation position is further processed by the image processing technique to calculate the deviation from the target irradiation position, and the object to be processed is calculated based on this deviation correction signal. Since the XY table on which is mounted can be controlled and the deviation can be automatically corrected, fine processing with accurate position accuracy can be performed.

Further, according to the invention of claim 4, the laser processing apparatus is a CO ₂ laser apparatus for fine processing, and it is possible to set the processing origin, which is the irradiation position of the processing start, which could not be conventionally achieved with high positional accuracy. This is made possible by the present invention, and it is possible to expand the application of fine processing of the CO ₂ laser device for fine processing.

According to the invention of claim 5, the object to be machined is an FPC, a molded product or the like which requires machining position accuracy, and the effect of the present invention can be sufficiently exerted so that machining can be carried out at an accurate position. You can do it and your requirements are met.

[Brief description of drawings]

FIG. 1 is an overall block diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining the control method of FIG.

FIG. 3 is a control flow chart of FIG. 1.

FIG. 4 is an overall block diagram of an apparatus according to a conventional example.

[Explanation of symbols]

 1 Laser Oscillator 3 Laser Light 5 Mask 5 7 Total Reflection Mirror 9 Processing Lens 11 Object to be Processed 13 XY Table 15 Coaxial Observation Device 17 Visible Laser Oscillator 19 Optical Path of Invisible Laser Light 21 Total Reflection Mirror 23 Half Mirror 25 Beam Combiner 27 ring light (light) 29 CCD camera 31 optical path of reflected light 33 optical path of visible laser light 35 monitor 37 personal computer (arithmetic processing means) 39 NC control device (control means)

Claims (5)

[Claims] 1. A laser processing apparatus for guiding an invisible laser beam from a laser oscillator to an object to be processed,
A coaxial observation device in laser processing for observing the irradiation position of the invisible laser light on the object to be processed, and sending the visible laser light to the object to be processed coaxially with the optical path axis of the invisible laser light, A coaxial observation device in laser processing, characterized in that reflected light of visible laser light is captured by a CCD camera and the captured image is displayed on a monitor. 2. A laser processing apparatus that guides invisible laser light from a laser oscillator to a processing target through a processing lens and performs processing, and observes the irradiation position of the invisible laser light on the processing target. A coaxial observation device in laser processing, a visible laser oscillator that outputs a visible laser light, and the output visible laser light invisible to send to an object to be processed coaxially with the optical path axis of the invisible laser light. A beam combiner that is provided obliquely to the optical path axis of the laser light and that transmits the invisible laser light and reflects the visible laser light, a light that is provided near the processing lens and illuminates the object to be processed, and a visible laser light The reflected light from the irradiation position of the processing target object and the reflected light from the processing target object illuminated by the light are taken in through the beam combiner C
A CD camera, a half mirror for branching an optical path of an image toward the CCD camera and an optical path of visible laser light from the visible laser oscillator, and a monitor for displaying an image captured by the CCD camera. Coaxial observation device for laser processing. 3. An arithmetic processing means for processing the captured image by an image processing technique to calculate a deviation from a target irradiation position and outputting a deviation correction signal, and placing a processing object on the basis of the deviation correction signal. 3. The coaxial observation device in laser processing according to claim 1, further comprising: a control unit that controls the XY table to correct the deviation. 4. The coaxial observation device in laser processing according to claim 1, 2, or 3, wherein the laser processing device is a CO ₂ laser device for fine processing. 5. The object to be machined is an FPC, a molded product, or the like, which requires a machining position accuracy.
A coaxial observation device in laser processing according to 2, 3, or 4.