JPS63235089A - Laser beam scanner - Google Patents

Abstract

PURPOSE:To improve control accuracy and stability by providing a means correcting slippage from standard position of a laser beam scanned by a galvanometer type scanner to a laser beam scanner. CONSTITUTION:In the case of executing the standard position correction, light 14 is turned off by a motion control device 5 through a scanner control circuit 16, and the standard light source 15 is turned on. After this standard light passes a dichroic mirror 12, it passes a lens 11 and a mirror 17 through scanning mirrors 10, 8 controlled to the standard rotating angle and is condensed by a lens 18. It is imaged by a video camera 19 and inputted to a standard position detecting circuit 20 as a video signal. After that, the video signal 204 of the position of standard light is compared with the comparing level 203 (not shown) by a comparator 301 and detected as a standard position signal 205 (not shown), and information of the position of standard light is extracted. The slippage of the detected valve from the standard value is calculated and corrected by the motion control device 5, the corrections of the scanning position, besides the position coordinate of the laser beam, are executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser beam scanner used in various radar processing devices such as a radar trimming device.

[Conventional technology]

A galvanometer scanner is one of the laser beam scanners used in various radar processing devices.

Conventionally, in order to control the scanning position using a Garneau 4-nometer scanner, a pair of electrodes is installed on the rotation axis side of the scanning mirror and on the opposite fixed part side, and nine rotation angles are determined based on changes in the capacitance between the electrode pair. A capacitance sensor method is used to detect and control the

[Problem that the invention seeks to solve]

In the conventional capacitance sensor method described above, since feedback is not based on the actual scanning position of the laser beam, if the capacitance sensor drifts due to changes in ambient temperature or changes over time, the amount of drift will directly affect the laser beam. This caused a drift in the scanning position and a deterioration in the stability of the scanning position.

In the case of an XY table type beam scanner using a linear motor, stable control with one position accuracy can be achieved compared to a galvanometer type beam scanner, but there are problems in that the operation speed is slow and it is expensive.

The present invention solves such problems of the conventional ones [Means for solving the problems] The laser beam scanner of the present invention includes: (1) a reference light source for positional deviation correction; means for branching the reference light from the laser beam path and guiding it to the video camera when the reference light is positioned at a position thought to be the position of the video camera; The apparatus includes means for detecting the amount of deviation, and means for correcting the detected amount of deviation by adding it to the coordinates of the scanning position of the laser beam.

〔Example〕

Next, nine aspects of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a radar processing apparatus including a laser beam scanner according to an embodiment of the present invention. This radar processing device has a Nd:YAG radar light source 1. Rade light control device 2. Galvanometer type scanner 3. Reference position detection device 4. The operation control device 5 is fully equipped.

The laser beam shown by the dotted line emitted from the Rade light source 1 has its diameter expanded by the beam expander 6, then enters the lupanometer scanner 3, is deflected by the scanning mirrors 8 and 10, and then passes through the lens 11. The light is then reflected by the dichroic mirror 12 and irradiated onto a desired processing position on the workpiece 13.

Under normal conditions without reference position correction, the illumination light emitted from the illumination 14 is reflected from the workpiece 13, while the infrared Rede light is totally reflected, and the dichroic mirror reflects about half of the visible light. -12 and reflected by lens 11
．． A dichroic mirror 17 that totally reflects Rede light, which is infrared light, and transmits visible light, via a scanning mirror 10°8.
The light passes through the lens 18, is focused by the lens 18, and is sent to the video camera 19.
The laser beam is imaged and displayed on the video monitor 21 as a laser beam scanning position.

When performing reference position correction, the illumination 14 is controlled by the operation control device 5.
Then, the light is turned off via the scanner control circuit 16t, and the reference light source 5 is turned on. This reference light is.

As shown by the dashed line, the dichroic mirror 17 passes through the dichroic mirror 12, passes through the lens 11, passes through the scanning mirrors 1o and 8 controlled to the reference rotation angle, and then passes through the dichroic mirror 17.
The light passes through the lens 18, is focused by the lens 18, and is sent to the video camera 19.
, and the video signal a is sent to the reference and position detection circuit 20.
is entered as .

Figure 3 is a block diagram showing an example of the configuration of a reference position detection circuit.The reference position detection circuit in this figure detects the position of the reference light as shown in Figures 2(,) and 2(b). , the video signal 204 is compared with the comparison level 203 by the comparator 301 and detected as a reference position signal 205. As the position information of the reference light, the vertical position detector 302 detects N in the vertical direction.
= (nl + n2)/2 In the horizontal position detector 303, T=(T1+T2)/2 in the horizontal direction.
Extract seconds. The reference value N in the operation control device 5 of FIG. , To, and the detected N and T, and multiply this by the unique proportionality constants CX and CY to obtain the Y-axis direction deviation ΔY=CY(N-No) and the X-axis direction deviation nHΔX= C
K(T-TO) is calculated and this value is added to the position coordinates of the laser beam to correct the scanning position.

〔Effect of the invention〕

As explained in detail above, the laser beam scanner of the present invention is equipped with a means for correcting the amount of deviation from the reference position of the laser beam scanned by the galvanometer type scanner, and also has means for correcting the deviation amount from the reference position of the laser beam scanned by the galvanometer type scanner. Since this can be done at the time of replacement, it has the effect of greatly improving stability without reducing control processing capacity.

Furthermore, since this method is closer to a closed-loop control method than the conventional open-loop control method that detects and controls the rotation angle of the scanner, it has the effect of improving control accuracy accordingly.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a laser processing apparatus including a laser beam scanner according to an embodiment of the present invention, and FIG.
a) and FIG. 2(b) are diagrams for explaining an outline of a method for detecting a reference position by a reference position detection circuit, and FIG. 3 is a block diagram showing an example of the configuration of the reference position detection circuit. Explanation of symbols: 1...Nd:YAG lede light source, 2...
・Laser light control device, 3... Galvanometer type scanner. 4... Reference position detection device, 5... Operation control device, 6
...Beam extractor, 7.9-... is a luvanometer. 8.10...Scanning mirror, 11...Lens, 12°17...Dichroic mirror, 13...Workpiece. 14--Lighting, 15--Reference light source, 16--Scanner control circuit, 18--Lens, 19---Video camera. 20...Reference position detection circuit, 21-...Video monitor, respectively. Figure 2 (a) Figure 2 (I))

Claims (1)

[Claims] 1. In a laser beam scanner that scans a laser beam to a desired position using a galvanometer type scanner, a reference light source is provided for positional deviation correction, and the laser beam scanner is positioned at a position that is considered to be the position of the reference light source. means for branching the reference light from the reference light source from the path of the laser beam and guiding it to the video camera; and a deviation between the reference position of the video signal from the video camera and the position of the reference light on the video signal. A laser beam scanner comprising: means for detecting the amount of deviation; and means for correcting the detected deviation amount by adding it to the coordinates of the scanning position of the laser beam.