JPS63221204A - Determining method for teaching point by optical displacement gauge - Google Patents

Abstract

PURPOSE:To accurately determine a teaching point by finding coordinates of two points on a work of specific height from an optical displacement gauge across a tape stuck on the surface of the work at equal intervals, and determining the coordinates of the teaching point under the tape. CONSTITUTION:An optical displacement gauge 1 is used to find the two points on the work 3 where a height detection signal VH' is stable across the tape 3A at equal intervals from a work surface state detection signal VLD'. Namely, coordinates on the work 3 are stored covering a necessary range and the coordinates of the irradiation points 41 and 45 on the work 3 across the tape 3A at equal intervals are found when the tape 3A is detected and when the displacement gauge is put a specific distance from the tape 3A. Then linear approximation between the two points is performed to find the mid-point and the coordinates of the teaching point 5 is computed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for determining a teaching point using an optical displacement meter, which is used when inputting teaching data to a device that cuts a workpiece using, for example, a laser beam. This invention relates to a method for determining points with high accuracy.

[Prior Art] FIG. 2 is shown, for example, in FIG. 4 of Japanese Patent Application No. 59-81915, and is a diagram for explaining how an optical displacement meter detects the surface condition of a workpiece and the distance to the workpiece.

In the figure, (1) is an optical displacement meter, (2) is a laser beam output from a semiconductor laser (not shown) built into this optical displacement meter (1), (3) is a workpiece, and (3^) is this Tape affixed to the surface of workpiece (3), such as black tape (
4) is the light spot I projected onto the workpiece (3).The received light image of this light spot (4) is the light displacement meter (1).
) and processed by built-in channels (not shown). When such an optical displacement meter (1) is moved at a constant speed in the direction of the arrow, a signal VLD that detects the condition of the surface of the workpiece (3) and a signal from the optical displacement meter (1) to the surface of the workpiece (3) are transmitted. It outputs a signal ■H that detects the height h which is the distance of .

Note that the surface state detection signal VLD is used for each workpiece (3).
) and the difference in the amount of light incident on the optical displacement meter (1) from the tape (38), a high level tape detection signal B is generated where the tape (3^) is present. In addition, the height detection signal V
Since the optical displacement meter (1) is moved at a constant height h relative to the workpiece (3), H becomes a signal at a nearly constant level.

[Problems to be Solved by the Invention] However, when determining the teaching point using such an optical displacement meter (1), it is difficult to teach the point where the optical slot 1-(4) hits the end face of the tape (3^). If it is set to a point, the value of the height detection signal vH will fluctuate due to the influence of the end face of the tape, and the reflected light of the optical spot (4) will be blocked by the corner of the tape (3^), causing the optical displacement meter (1) to There is a problem in that insufficient light is received, making measurement impossible.

Furthermore, even if the teaching point is set at a place where the light spot (4) hits near the center of the top surface of the tape (3^), the thickness of the tape (3^) and the degree of application [for example, if the application of the tape (3^) is incomplete, If there is a gap between the lower surface of the tape (3^) and the surface of the workpiece (3), errors may occur, so there is also the problem that preferred teaching points cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and an object of the present invention is to provide a method for determining a teaching point using an optical displacement meter, which can accurately determine a preferred teaching point.

[Means for Solving the Problems] The method of determining teaching points using an optical displacement meter of the present invention is such that the tape attached to the surface of the workpiece is sandwiched at equal intervals and the height from the optical displacement meter is stable. Find the coordinates of two points on the workpiece,
From these coordinates, the coordinates of the teaching point under the tape are determined.

[Operation] In the present invention, the teaching point is determined with high precision by ignoring the thickness of the tape attached to the surface of the workpiece and excluding places where the value of the height detection signal is inconsistent.

[Example] FIG. 1 is a diagram illustrating an example of the teaching point determination method using an optical displacement meter of the present invention, and includes (1), (2), (3),
(3^) is as explained in connection with FIG.

In the figure, (41) to (45) are the irradiation positions of the light spot [(4) in Figure 2], (5) is the preferred teaching point,
It is located below the tape (3^) and near the center of the surface of the workpiece (3) in the tape width direction, VLD' corresponds to VLD, and vH' corresponds to ■H.

As mentioned above, at the locations where the light spot hits the end face of the tape (3^), that is, at the irradiation positions (42) and (44), the height detection signal VH' of the optical displacement meter (1) is affected by the tape end face. The value may fluctuate, or the reflected light of the light spot may be blocked by the corner of the tape (3^), making measurement impossible. Also, the location where the light spot hits near the center of the top surface of the tape (3^), that is, the irradiation position! (43), the tape (
3^) Errors may occur in the detection signal due to the thickness and attachment condition.

Therefore, in this invention, the thickness of the tape (3^) attached to the surface of the workpiece (3) is ignored, and the value of the height detection signal In order to accurately determine the teaching point (5) by excluding the irradiation position i1J (42) and (44), an optical displacement meter (1) is used.
is used to sandwich the tape (3^) at equal intervals from the workpiece surface state detection signal VLD' and select two points on the workpiece (3), that is, the irradiation position (41) where the height detection signal vH' is stable.
) and (45), and from these coordinates, the coordinates of the teaching point (5) are determined.

For example, the coordinates on the workpiece (3) are memorized over a necessary range, and when the tape (3^) is detected and when the workpiece (3^) is separated from the tape (3^) by a predetermined distance, the tape (3^) is
Irradiation position (41) on the workpiece (3) that holds the ^) at equal intervals
Find the coordinates of and (45). Then, a midpoint is obtained by linear approximation between the two points, and the coordinates of the teaching point (5) are calculated.

At this time, it goes without saying that the workpiece surface state detection signal VLD' is used to detect the tape (3^).

[Effects of the Invention] As described above, according to the present invention, since the teaching point is determined in a method that does not depend on the tape itself at all, there is an effect that the teaching point can be determined with high accuracy.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining one embodiment of the present invention, and FIG. 2 is a diagram for explaining a detection method using an optical displacement meter. In the figure, (1) is an optical displacement meter, (3) is a workpiece, and (3) is an optical displacement meter.
^) is the tape, (41) and (45) are the irradiation positions, (
5) is the teaching point, VLD' is the workpiece surface state detection signal, V
l(' is a height detection signal. In the figures, the same reference numerals indicate the same or corresponding parts. 兇1Figures 41 to 45: Irradiation position 1

Claims (2)

[Claims] (1) A tape is attached to the surface of the workpiece, and an optical displacement meter is used to obtain a workpiece surface condition detection signal that detects the condition of the workpiece surface including the tape, and a height detection signal that is the distance to the workpiece surface. , find the coordinates of two points on the workpiece where the tape is equally spaced from the workpiece surface condition detection signal and whose height is stable from the height detection signal, and from these coordinates, place the tape under the tape. A teaching point determining method using an optical displacement meter, characterized in that the coordinates of a certain teaching point are determined. (2) A teaching point determining method using an optical displacement meter according to claim 1, wherein the teaching point is located near the center of the tape in the width direction.