| 摘要 |
<p>PURPOSE:To perform the input of coordinate with a few number of sensors by calculating the coordinate of an input point based on a geometric condition formed by the transmission paths of a direct wave and a reflected wave from the transmission time of the direct wave and the reflected wave. CONSTITUTION:An oscillation pen 3 generates the direct wave arriving from the input point directly to an oscillation sensor 6 and the reflected wave arriving via reflection on an oscillation transmission plate 8. A detection signal from the sensor 6 is inputted to a direct wave detection circuit 10 and a reflected wave detection circuit 11. The circuits 10 and 11 detect the arrival timing of wave components, respectively, and the clock information of a clock counter 14 is latched at latch circuits 12 and 13 by the above detecting output. The arrival time information of latched direct wave and reflected wave are inputted to a controller 1, and the controller 1 calculates the coordinate of the input point from the time information based on the geometric condition formed by the transmission paths of the direct wave and the reflected wave. In such a way, it is possible to reduce the number of the oscillation sensors to one.</p> |
