| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an ultrasonic coordinate input device capable of accurately measuring the distance between a moving body and receivers without making a user conscious of the calibration of sound speed. SOLUTION: This coordinate input device comprises a moving body 10 having an ultrasonic transmitter, and a fixed unit 1 having at least two ultrasonic receivers 7, 8 and a synchronizing means for synchronizing transmission from the moving body 10, and inputs the coordinates of the moving body 10 from the arrival time of ultrasonic wave transmitted from the ultrasonic transmitter, up to the receivers. In this constitution, an ultrasonic transmitter 9 arranged at a prescribed distance from two ultrasonic receivers 7, 8 is arranged in the fixed unit 1.</p> |
