| 摘要 |
<p>PURPOSE:To enhance the resolution to two folds by allowing a constant-current to flow to a midpoint of a resistor, driving th resistor, that it, an electrode group in the form divided into two and allowing each of them to provide an output, and using one of outputs thereof. CONSTITUTION:Since a constant-current is supplied from the center of resistors 10, 20, a potential is generated in the direction in which a contact point is positioned on the left and the right from a midpoint of the resistors 10, 20. Subsequently, when the potential across the resistors 20(10) is brought to differential by a pair of differential amplifiers 5a, 5b(6a, 6b) whose input polarities are reversed, respectively, each voltage output of the left and the right based on the midpoint as a reference is obtained. Accordingly, from an A/C converter 7, two coordinate values of the left and the right on the Y side and two coordinate values of the left and the right on the X side are obtained. In such a way, by the left and the right half each of the resistors 20(10), the A/D converter 7 is utilized fully, and the resolution can be enhanced to just two folds.</p> |
