| 摘要 |
PURPOSE:To perform accurate positional detection, by calculating the position of the leading end of a display pen by receiving the signals of plural ultrasonic oscillators provided to the display pen by plural ultrasonic receivers provided on a drawing picture. CONSTITUTION:First and second ultrasonic oscillators 3, 4 are provided to a display pen 1 in the axial direction thereof and ultrasonic receivers 6-8 are provided to the corner parts on a drawing picture 5 to receive ultrasonic waves emitted from the oscillators 3, 4. From the oscillators 3, 4, the period ultrasonic waves shown by a wave form (a) are emitted and the receivers 6-8 receive the ultrasonic waves emitted with time delay to obtain the output with a wave form (b). The section of the wave form (d) from the rising of the wave form (a) to that of the wave form (b) comes to the distance data of the receivers 6-8 and the oscillators 3, 4. The position of the leading end of the display pen 1 on the drawing picture 5 is operated and calculated from the distance data (d) and the mount position data of the oscillators 3, 4 in the display pen 1. |
