PURPOSE: To make a display screen large, to increase its productivity and reduce the cost, and to improve the precision of coordinate detection.
CONSTITUTION: A switching circuit 8 selects the side of a display control circuit 4 in a display period and the side of a detection control circuit 5 in a coordinate detection period. A row electrode driving circuit 2 outputs row electrode scanning pulses in the display period to scan row electrodes G1-G6 in order. A column electrode driving circuit 3 outputs column electrode scanning pulses in an (x)-coordinate detection period to scan column electrodes S1-S6 in order. A coordinate detecting circuit 7 detects the tip coordinates of a detection pen 6 on the basis of a voltage induced at the tip electrode of the detection pen with the scanning pulses. Thus, the (y) coordinate of the tip of the electronic pen 6 is detected in the display period and the (x) coordinate is detected in the (x)-coordinate detection period to make the display screen large-sized, increase the productivity, and reduce the cost, and also to improve the precision of the coordinate detection.
TOMIYOSHI EI
TAKEDA MAKOTO
