Electro=optical modulation system - has bias and differential amplifiers associated with mean value and inversion circuits of comparator

摘要

The electro optical modulation system utilizes electro optical effect of a crystal. The electro optical modulation system comprises a voltage comparator for comparing a modulated light intensity signal with a reference voltage. A bias controlling device feeds a differential signal between mean value signal of the output of the voltage comparator and mean value signal of the inverted output of the voltage comparator, to an optical modulator as a bias voltage. The modulator may be used for video discs or pulse code modulation audio discs.