| 摘要 |
<p>PURPOSE:To improve readout precision at the end part of a plane plate by linearly varying the phase of a magnetic field, perpendicular to the plane plate, in accordance with a position on the plane plate, by providing a means of varying the current amplitude of each coil arranged on the plane plate. CONSTITUTION:In the direction of the width A of the plane plate 2 of a coordinate reader, coils 3-1, 3-2...3-N having the same characteristics are arrayed in a line and then energized by power voltages e'1...e'N from AC power sources 4-1...4-N. In this case, when the amplitude of an optional voltage e'n is A'n and a phase angle is phin, the amplitude A'n decreases gradually more the coil 3-1 and 3-N at both the end parts than coils at the center part. Then, the phase of a magnetic field perpendicular (Y direction) to the plane plate 2 is varied with regard to the position on the plane plate 2 to improve readout precision at the end part of the plane plate 2.</p> |
