| 摘要 |
PURPOSE:To attain highly accurate data transmission with a simple device by sending a differential optical signal from plural light sources through plural optical transmission media corresponding to the plural light sources respectively. CONSTITUTION:A differential drive circuit 1 converting a digital signal inputted from an input terminal 7 into complementary signals D, inverse of D and applying them to 1st light emitting element 11 and a 2nd light emitting element 12 is provided in an optical transmitter 10. The optical signals sent from the light emitting elements 11, 12 are transmitted through optical transmission lines 15, 16. A signal of repetitive 1, 0 from the optical transmitter 10 to a photodetector 20 is sent as an optical signal. A midpoint of output levels 0, 1 of the digital signal is always constant in the case of reception because the signal receives attenuation or the like through the transmission line under the same condition. Thus, it is possible to fix a reference voltage in the discrimination circuit and communication with high accuracy is attained. |
