| 摘要 |
PURPOSE:To improve the S/N of this system by adding a branched part of signals inputted to a transmitter to signals received by a receiver as a neutralization signal after adjustment. CONSTITUTION:Transmitted signal DATA-IN is supplied to an LED drive circuit 2 through an input buffer l and transmitted to a transmission circuit after the electric signal is converted into signal light by means of a light source 3. The signal light made incident to a photoreceptor element 4, on the other hand, is converted into electric signals. The converted electric signal is led to a differential amplifier 6 after the signal is amplified by means of an amplifier 5. Thereafter, received signal DATA-OUT is obtained from a waveform reproduction circuit 7 through an output buffer 8. In addition, part of the output of the input buffer l is supplied to the differential amplifier 6 as a neutralization signal after its damping quantity and delay time are adjusted by means of an attenuation circuit 9 and delay circuit 10. The damping quantity and delay time by means of the circuits 9 and 10 are made adjustable and adjusted in advance so that the neutralization signal can become the same as a reflected signal component reflected in a transmission line. |
