| 摘要 |
PURPOSE:To convert plural independent signals into an optical signal with a single light emitting diode by supplying a synthesized drive current corresponding to plural input signals to the light emitting diode. CONSTITUTION:When an input signal (a) is fed to a base of a transistor(TR) 2 through an input terminal 1, a current (b) in response to the signal(a) flows to a collector of a TR 3 in a differential pair comprising TRs 2,3 and an LED 4 inserted in a collector circuit of the TR 3 sends an optical signal (c). When an input signal (d) is fed to a base of a TR 12 through an input terminal 13, the TRs 12,3 act like differential operation, a current (e) in response to the signal (d) flows and the LED 4 sends an optical signal (f). When input signals(a), (b) are given to input terminals 1,13 simultaneously, the currents (4b), (e) flow to the collector of the TR 3 independently and a synthesis drive current (j) of the both flows to the LED 4, in which a synthesis optical signal (h) in response to the current (j) is generated. |
