| 摘要 |
<p>PROBLEM TO BE SOLVED: To make a coordinate input device high in portability and low in cost by applying a voltage to a vibration transmission plate and detecting its vibrations at an electrode position outside a coordinate input area. SOLUTION: Vibrations are generated by the vibration transmission plate 8 by bringing an input pen 3 into contact with the vibration transmission plate 8 and applying a voltage along the thickness of the vibration transmission plate 8. Coordinates is inputted by specifying the point in the area A (coordinate input surface) with the input pen 3. Electrodes 6a-6d for vibration detection which convert mechanical vibrations into electric signals are constituted at the four corners on the top surface (coordinate input surface) of the vibration transmission plate 8. The mechanical vibrations detected by those electrodes 6a-6d are converted into the electric signals, which are amplified and then inputted to a signal waveform detecting circuit 9. This electric signal becomes a signal which indicates vibration timing to the electrodes 6a-6d through waveform signal processing and is outputted to an arithmetic control circuit 1. Then the arithmetic control circuit 1 detects the time of vibration arrival at the electrodes 6a-6d and calculates the distances between the input pen 3 and electrodes 6a-6d to calculate the coordinates.</p> |
