OPTICAL REGISTER DEVICE

PURPOSE:To easily obtain an optical integrated circuit executing a logical operation by providing the circuit with an optical register device using an optical RS-FF circuit to switch the light emitting state of two light emitting areas by turning on/off two input optical pulse signals. CONSTITUTION:When reading-out signal light W is made incident, output light rays Y1-Y5 are simultaneously read out from FF circuits FF1-FF5. At the incidence of sift signal light Z, outputs of the respective FF circuits are shifted to the right FF circuits respectively. In these FFs, current values from constant current sources J1, J2 are set up in a specified range to a threshold value. When a photodetecting area D1 is not conducted, a light emitting area S2 is in a light emitting state. At that time, the area D2 is conducted by the incidence of light from the area S2 and the area D1 is in the non-emitting state. If liht is made incident to the area D1 from the external, the area D1 is conducted and current flowing into the area S2 is reduced lower than the threshold value. Consequently, the area S2 is turned to the non-light-emitting state and the area D2 is also not conducted so that current more than the threshold value flows into an area S1 and the are S1 is turned to the emitting state.