SIGNAL TRANSMISSION SYSTEM OF COORDINATE INPUT DEVICE

摘要

PURPOSE:To transmit coordinate information that a coordinate detection pen detects and additional information other than coordinate information that the pen has on a time-division basis through the same signal line or by radio of the same channel. CONSTITUTION:A tablet is a grating in nXm units consisting of Y-directionally arranged common electrodes 4 and X-directionally arranged segment electrodes 5. The electrodes 4 and 5 are driven by driving circuits 2 and 3 to turn ON and OFF. A control circuit 1 performs driving timing control over the driving circuits 2 and 3, a wired type detection pen 6, and a cordless type detection pen 7. The main body of a system which uses the cordless type pen 7 is provided with a transmission and reception unit 8 for having a communication with the pen 7. Signals sent from the pens 6 and 7 directly or through the transmission and reception unit 8 are separated and converted by a detecting circuit 9 into coordinate data and various additional information.