| 摘要 |
<p>PURPOSE:To attain coordinate reading with high correcting accuracy by arranging oppositely a detection coil to a sense line board at a desired position of the said board to improve the detecting accuracy of expansion/contraction of the sense line board. CONSTITUTION:Assuming that the sense line board 1 is expanded by temperature change and an absolute position coordinate X0 goes to X0', then an absolute coordinate X1 of, e.g., an exciting coil 4 placed at the coordinate X1 goes to X1'(=X1.X0/X0') which is converted by an arithmetic control circuit because of the position deviation of a sense line attended with the elongation of the sense line board 1. Then the elongation of the sense line board 1 is detected from the relation of relative position between the detection coil 7 and the sense line of the absolute position having a position deviation due to elongation and the arithmetic control circuit makes correction operation to cancel the value X0/X0' by feeding back the said elongation, then the coordinate converted actually attains to the absolute coordinate corresponding to the position indicated by the exciting coil 4.</p> |
