JPH02148367A - Method for reading reading mark for automatic drawing machine - Google Patents

Abstract

PURPOSE:To read a reading mark with high accuracy by parallel-moving a sensor in a direction crossing the two straight lines of the mark and detecting the 4-point position of the two lines, and then, finding the intersection of the two lines from the 4 point positions. CONSTITUTION:A reading mark is constituted of two straight lines intersecting each other at a detecting point P and the two lines are drawn so that the two lines can intersect each other in a V-form. A sensor 16 is moved to a point S1 against a sheet 6. Then the sensor 16 is moved to another point S2 along Y rail 8 and two points A and B are detected with the sensor 16. A controller stores positions of the two points A and B based on the output of a counter which counts the moving quantity of a pen head 10 along the Y rail 8. The sensor 16 is moved to a point S3 after the sheet 6 is moved and further moved to another point S4 along the Y rail 8 to detect points C and D. Positions of the points C and D thus detected are stored. The controller finds the intersection P of the straight line passing the points A and C and the other straight line passing the points B and D.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for reading a reading mark on a sheet of paper using a sensor provided in a pen head in an automatic drafting machine.

[Conventional technology]

When drawing long data using multiple frames,
Draw connecting reading marks for position correction between frames,
There is a method in which this mark is read by an optical light reflection sensor installed in the pen head and the position between frames is corrected, but the above read mark is a shape where two straight lines intersect at a right angle, as shown in Figure 5. It becomes. When reading this reading mark, move the sensor from the reference point in the Y direction, then change the direction in the X direction in the order of 1 and 2, and then
Read point B, then move the sensor from another reference point in the Y direction, change direction in the X direction in the order of 3 and 4, and read points C and D on the two straight lines, as described in A above.

From the positions of B, C, and D, the position of the intersection P of the two straight lines is determined.

[Problem that the invention seeks to solve]

According to the above method, when reading each point on two straight lines, it is necessary to convert the relative movement of the sensor to the paper by 90 degrees.5 At this time, the drive system for moving the sensor relative to the paper is shown in Figure 5. As shown in the figure, the Y drive system is converted to the X drive system. As described above, when the drive system is converted during reading scanning, there is a problem in that errors are likely to occur in reading the reading marks. The present invention aims to eliminate the above-mentioned defects.

[Means to solve problems]

In order to achieve the above object, the present invention provides a method in which a sensor is provided in a pen head linked to a numerical control system, and the sensor reads a reading mark extending in three directions centering on a detection point provided on a sheet of paper. Translate the read mark at least twice in a direction that crosses the two straight lines, detect the four-point positions of the two straight lines of the read mark by this parallel movement, and determine the position of the intersection of the two straight lines from these four-point positions. This is how it was done.

〔Example〕

The structure of the present invention will be described in detail below with reference to embodiments shown in the accompanying drawings.

In FIG. 4, reference numeral 2 denotes a paper-driven automatic drawing machine, in which a paper 6 is fed in the front-rear direction in the figure by the rotation of a drive roller driven by an X motor on a paper placement surface 4, and
A pen head 10 movably attached to the rail 8 is configured to move along the Y rail 8 in a direction across the paper 6 by being driven by a Y motor. The pen bed 10 is equipped with a pen holder 14 for holding a pen 12 and an optical light reflection sensor 16. Said X
, Y motors are controlled by a controller, and the sensor 16 is connected to the controller.

Next, the operation of detecting the reading mark drawn on the paper 6 will be explained.

The reading marks intersect at the detection point P as shown in Figure 1.
It is composed of straight lines, and these two straight lines are drawn so that they intersect in a figure-7 shape. First, place the sensor 16 against the paper 6.
Move to Sl (block 1), then sensor], 6 to Y
Moving along the rail 8 to S2, the sensor 16 causes
A. Based on the output of a counter that detects 82 points and counts the amount of movement of the pen head 10 along the Y rail 8,
The controller stores the position of point A, 82 (block 2). Next, the paper 6 is moved and the sensor 16 is moved to S3 (block 3). Next, the sensor 16 is moved along the Y rail 8 to S4 to detect points C and D, and the positions of the points C and D are memorized (block 4). Find the intersection point P of the straight line passing through and the straight line passing through points B and D.

As shown in FIG. 2, in the case of a reading mark where two straight lines intersect at right angles, the sensor 16 is placed at
It moves linearly in a direction that crosses two straight lines relative to the coordinate axis at a predetermined inclination angle, for example, 45 degrees, and detects two points A and B by this inclination linear movement, and then,
The sensor 16 is linearly moved in a direction that crosses the two straight lines parallel to the above-mentioned inclined linear movement to detect points C and D, and point P is determined from the read detection data of the above-mentioned points A, B, C, and D. You can ask for it.

In the above embodiment, a paper-driven automatic drafting machine was used.
It can also be applied to flat type automatic drafting machines that move parallel in the direction.

〔effect〕

As described above, in the present invention, one point on each of two straight lines is determined by linearly moving the sensor relative to the paper in a direction that crosses the two straight lines, so the direction change is performed while the sensor is moving linearly relative to the paper. There is an effect that the reading mark can be read with high precision without any accompanying information.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram, FIG. 2 is an explanatory diagram of another embodiment, FIG. 3 is a flowchart, FIG. 4 is an external view, and FIG. 5 is an explanatory diagram of a conventional system.

Claims (1)

[Claims] (1) A method in which a sensor is provided in a pen head linked to a numerical control system, and the sensor reads a reading mark extending in three directions centering on a detection point provided on a sheet of paper, in which the sensor is moved across two straight lines of the reading mark. The reading mark is moved in parallel at least twice in the direction, and by this parallel movement, the four-point positions of the two straight lines of the reading mark are detected, and the position of the intersection of the two straight lines is determined from the four-point positions. How to read marks on an automatic drawing machine.