| 摘要 |
<p>PURPOSE:To provide a coordinate input device having a wireless vibration pen. CONSTITUTION:The input pen 1 for inputting ultrasonic vibration is set to be wireless, and the ultrasonic signal of a prescribed frequency is outputted at a prescribed period in asynchronizing with the control part of a main body. On the other hand, plural vibration sensors 2 provided in the prescribed positions of a vibration transmission board 3 detect the vibration. The control part measures transmission time till signals arrive at the respective sensors 2 from reference time which is appropriately decided, calculates (X, Y)-coordinates by the plural combinations of the sensors based on the transmission time, calculates backward the timing difference between reference time and the timing difference of ultrasonic signal output in the actual pen 1 and calculates the accurate coordinate value obtained by correcting the difference. Thus, the coordinate can be calculated without deteriorating precision with respect to the ultrasonic signal which is asynchronously inputted from the input pen 1, and the cordless type ultrasonic coordinate input device can be realized.</p> |
