PURPOSE: To contrive to simplify the circuit constitution by connecting a base of plural transistors(TRs) to each column signal line of a diode matrix via a diode and connecting each column signal line of the diode matrix to a prescribed power supply via a resistor.

CONSTITUTION: An output from the diode matrix is given to resistors 23, 25, 27, 29 whose one terminal is connected to a power terminal 9 and connected to each anode of diodes 35∼38, each cathode of the diodes 35∼38 is connected to each base of the output TRs 31∼34 of the logic circuit and to other terminal of the resistors 24, 26, 28, 30 whose one terminal is connected to ground. Emitters of the TRs 31∼34 are connected in common and connected to the anode of the diode 43 and the cathode is connected to ground. Then the input signal is processed by the diode matrix and the output TR of the logic circuit is subject to on/off control by the Lo or Hi condition of the input signal. Thus, the circuit is simplified.