INPUT DEVICE FOR MULTI-ITEM INFORMATION

PURPOSE:To keep a detection signal level constant at all times independently of the number of sheets, by increasing the power supply voltage supplys to a decoder to keep constant the level of a detected signal of a detection pen which is automatically decreased as the number of character sheets located on a tablet increases. CONSTITUTION:A multi-item information input device of electrostatic coupling system tablet consists of X axis group of scanning lines 2-1 and 2-2 provided with many numbers almost in parallel, Y axis group scanning lines 3-1, 3-2... crossing to them almost in parallel by many numbers, X axis decoder 10 applying a scanning signal to them, Y axis decoder 11, and detection pen which detects the scanning signal applied on the scanning lines with electrostatic coupling. The character sheets are located on the tablet, and the number of character sheets is counted with a character sheet counter 13, and the supply voltage to the decoders 10, 11 is controlled with a voltage control circuit 14 with this counter output.