NOISE REMOVING CIRCUIT FOR CHARGE COUPLING DEVICE

• Main Author: DAIHO MASAHIRO
• Format: Patent
• Language: English
• Published: 26.11.1992
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

PURPOSE:To display a stable noise suppressing effect by utilizing the reflection of a delay line, finding out a difference between a field through level and a signal level by an effective signal voltage and removing components other than an effective signal voltage. CONSTITUTION:An output signal a1 from a preamplifier 11 is supplied to the delay line 13 and a buffer circuit 14 through a resistor 12. A signal b1 delayed only by a delay time tau through the line 13, inverted at its phase on an output terminal, reflected, and then delayed by the delay time tau is reached to an input terminal. In the input terminal, a difference between the signals a1, b1 is found out and outputted through the circuit 14 as an output signal c1. The effective signal voltage for picture elements is modulated at its amplitude by the signal c1, the modulated voltage appears as a negative voltage to a reference voltage and waveform components more than a fixed voltage out of the signal c1 are removed by a clipping circuit 15. A DC voltage is removed through a notch filter 16 and only an effective signal appears. Noise components other than the effective component are removed and only the effective component can be accurately extracted.