Patent ID: 7570252

Claim:
A pen input/display device, comprising: an input pen enabling a pen input on a display panel; infrared transmission means and ultrasonic transmission means provided on the input pen; infrared receive means and at least two ultrasonic reception means, provided on the display panel, receiving an infrared signal and an ultrasonic signal simultaneously transmitted respectively from the infrared transmission means and the ultrasonic transmission means provided on the input pen, when a pen tip of the input pen is in contact with the display panel; and display control means computing a contact position of the pen tip on the display panel from a result, containing a time delay, of receiving the ultrasonic signal by the at least two ultrasonic reception means with reference to a time when the infrared receive means receives the infrared signal, said input pen including pen pressure sensor means sensing pen pressure when the pen tip is in contact with the display panel; and pen pressure information infrared transmission control means controls the infrared transmission means to transmit an infrared signal which changes in accordance with the pen pressure, wherein the input pen further includes sequence input means enabling inputs of a series of pen pressure levels in an order of frequency of use; and the pen pressure information infrared transmission control means controls the infrared transmission means to change the infrared signal in accordance with frequency of use of individual pen pressure levels as sorted through the sequence input means.