| 摘要 |
PURPOSE:To attain stable clamp operation by executing feedback clamp after blanking processing not including a reference black level portion is applied to obtain a signal to be clamped having a long period. CONSTITUTION:DC regeneration is attained by clamping a reference black level portion 101 with a clamp pulse CPOB1 at a clamp circuit 4 by taking noise invaded from a clock generator 3 into account in portions excluding the reference block level portion 101 in a horizontal blanking signal portion 102 of a PAM signal S1. The signal is amplified by an amplifier 5 at the next stage, a blanking pulse BL1 is applied by the 1st blanking circuit 6 thereby performing blanking processing and black clip processing to obtain a signal S2. The optical reference black level signal 101 is reserved in this signal S2. Thus, excellent clamping is attained by clamping the stable signal to be clamped newly formed by a clamp pulse CP1 having sufficient wider pulse width than that of the clamp pulse CPOB1 in a feedback clamp circuit 8 at the post-stage. |
