Patent attributes
When a display panel is in contact with the pen tip of an input pen, an infrared receiver and at least two ultrasonic receivers, provided on the display panel, receive respectively an infrared signal and an ultrasonic signal simultaneously transmitted from an infrared transmitter and an ultrasonic transmitter, and computes the contact position of the pen tip on the display panel from a result, containing a time delay, of the ultrasonic receiver receiving the ultrasonic signal with reference to a time when infrared signal is received. The input pen includes a piezoelectric element sensing pen pressure when the pen tip is in contact with the display panel and a microcomputer controlling a infrared transmitter to transmit an infrared signal which changes in accordance with the pen pressure. Thus, in ultrasonic pen input operation, information on the sensed pen pressure is wirelessly transmitted to the device main body, so as to provide a pen input/display device realizing multifunctional, high performance pen input operation based on the pen pressure information in a simple manner.
