| 摘要 |
PURPOSE:To reduce the number of times of required scanning of electrode lines, to attain high speed, simplicity in structure and more cost reduction by specifying a coordinate to be commanded depending on the quantity of a charging current of the group electrode line. CONSTITUTION:A CPU applies an address signal AD to a driver DX1 via a multiplexer MPX1. The driver DX1 applies a sequential scanning pulse to the group electrode line according to the address AD. A charging current flows to each group electrode line, a signal SS according to the quantity is generated across a resistor RS and stored in a prescribed number of a RAM via an amplifier AMP, an AD converter and an IO. The CPU activates sequentially drivers DS2, DY1, DY2 to store the signal to a prescribed address of a RAM. The CPU discriminates the contact positionof an input pen 12 based on a digital value of the detection signal SS.
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