PURPOSE: To provide the high-accuracy coordinate input device.
CONSTITUTION: When vibrations are applied to a vibration transmitting board 8 by a vibrating pen 3, they are transmitted through the transmitting board 8 and detected by vibration sensors 6a-6d. Only the prescribed frequency is extracted from the detected signal by a band pass filter 9, this signal is logarithmically amplified by a logarithmical amplifier 10 and afterwards, it is judged whether the signal reaches a prescribed level or not. When the signal reaches it, with that time point as transmission delay time, a distance from a coordinate indicator to the vibration sensors 6a-6d is calculated. Then, the input coordinate value of the vibrating pen 3 is calculated from the measured distance.
KANEKO KIYOSHI
TANAKA ATSUSHI
KOBAYASHI KATSUYUKI
YOSHIMURA YUICHIRO
