ULTRASONIC COORDINATE INPUT DEVICE

摘要

PROBLEM TO BE SOLVED: To eliminate directivity when the axial line of an ultrasonic input pen is inclined and to improve the precision of coordinate input by setting an ultrasonic wave transmission body to which plural ultrasonic wave reception elements are fitted. SOLUTION: The ultrasonic vibration transmission body 6 whose board thickness is set to 3-6mm is provided by using the material such as acrylic and glass. The plural ultrasonic wave reception elements 1-4 are fitted to the ultrasonic vibration transmission body 6. The coordinate of an input point is displayed on a display device 13 through a reception circuit 1 and an arithmetic circuit 12 based on signals detected in the ultrasonic wave reception elements 1-4. An ultrasonic wave is inputted to the ultrasonic wave transmission body 6 with the ultrasonic wave input pen 5. The coordinate of the point which is ultrasonic wave-inputted is calculated by using board waves which the ultrasonic wave reception elements 1-4 detect at first. Thus, directivity when the axial line of the ultrasonic wave input pen 5 is inclined can be eliminated and coordinate calculation precision can be improved.