| 摘要 |
<p>PURPOSE:To accurately specify a position indicated with an ultrasonic input pen by using the transparent cover body on the display surface of a display device as an ultrasonic wave propagation panel, and specifying the indicated position on the ultrasonic wave propagation panel by an ultrasonic wave transmitting means with an ultrasonic wave received signal received by an ultrasonic wave receiver. CONSTITUTION:A display device 1 is formed by arranging a front glass panel and a rear glass panel on the top and reverse surfaces of a pattern circuit connected to an arithmetic part through a PDP driving circuit. When a proper position on the ultrasonic wave propagation panel 2 is indicated with the ultrasonic pen, a coordinate calculation part specifies the indicated position and sends out an arithmetic document input signal. The ultrasonic wave receiver 4 is a piezoelectric vibrator 4 which has electrodes 4a formed on its top and reverse surfaces, and the piezoelectric vibrator 4 and a signal line 5 are put hermetically in a conductive shield structure 6 and shielded from electromagnetic noises from the PDP driving circuit and a discharging pattern circuit. Then a conductive pipe 9 is grounded.</p> |
