| 摘要 |
PURPOSE:To eliminate the need for large scale circuit constitution by converting plural parallel digital signals into an optical signal with one light emitting element and radiating the converted signal as an optical output signal. CONSTITUTION:Three transistors(TRs) Q1, Q2, Q3 are connected in parallel in a driving voltage circuit 12 and only one of them is turned on with respect to a set of input digital signals. Then a driving voltage 12a being an output of the TRs is varied by making the load resistors R1, R2, R3 of the TRs Q1, Q2, Q3 different from each other. Then a forward current of a light emitting element with respect to an optical output is decided by assigning the optical output of the light emitting element with respect to all sets 2<n> of digital signals inputted in parallel with (n) input terminals to output the forward current by (n) input signals. |
