ULTRASONIC COORDINATES INPUT DEVICE

摘要

PROBLEM TO BE SOLVED: To prevent coordinates input accuracy from being lowered by the attenuation of propagated ultrasonic waves. ;SOLUTION: Ultrasonic waves are inputted to an ultrasonic propagating object 4 provided with plural receiving elements 5 with an ultrasonic input pen 1 and the ultrasonic waves propagated through the ultrasonic propagating object 4 are received by the respective receiving elements 5. The peak value information and phase information of respective received waves are found by a detection circuit 6, at least two receiving elements 5 are selected by an operation circuit 7 based on these both kinds of information so that the level of received waves can be high and further the phase can be equal to each other, and the coordinates of an ultrasonic wave input position is calculated from the received waves of the selected receiving element 5.;COPYRIGHT: (C)1997,JPO