| 摘要 |
PURPOSE:To make it possible to transmit normally the light output of a light- emitting element from the first bit of a data string by a method wherein the respective L levels of an input signal to an optical transmission device and the output signal, which is set at the same level as that of this input signal, of a photodetector are clamped and the peak values of the clamped respective signals are added to a differential DC amplifier. CONSTITUTION:A bias current is changed by a bias current drive circuit 5 and the respective L levels of an input signal to an optical transmission device, which makes the light output of a light-emitting element 1 constant, and a signal, which is turned the output signal of a photodetector 3 to the same level as that of the input signal by an amplifier 20, are respectively clamped by clamping circuits 6 and 7. The peak values of the clamped respective signals are respectively detected by detection circuits 8 and 9 and the detected respective peak values are added to a differential DC amplifier 4. Thereby, the light output of the element 1 is turned to a normal level from a first bit of a data string and can normally be transmitted from the first bit of the data string. |
