| 摘要 |
PURPOSE:To stabilize inputting operation without being influenced by pen pressure by energizing piezo-electric ceramics on two sides of a board intersecting at right angles alternately, detecting a mechanical vibration by a pen having a built-in electromagnetic detecting coil, and calculating its time of propagation. CONSTITUTION:A sound wave originated by piezo-electric ceramics 2 propagates along a board 1 at a speed near to a longitudinal wave. The sound wave is detected by lowering a core 3 for electromagnetic pickup at a point 3a on the board 1. A signal from a coil 4 is amplified by an amplifier 6 and sent to a signal processing circuit 7 after waveform shaping. A pulse signal that energizes the piezo-electric ceramics 2 is sent from a pulse generator 5 to the signal processing circuit 7, and the time of propagation is measured by the signal processing circuit 7. The measured time is converted to the value of distance to obtain a coordinate value. By executing this alternately for X and Y axes, the coordinate of X, Y can be calculated and inputted.
|
