SECAM COLOR DECIDING DEVICE

摘要

PURPOSE:To prevent a color signal having a deteriorated S/N as well as an erroneous decision when noises are produced, by providing a clip amplifier at the preceding stage of an fH/2 sine wave generator. CONSTITUTION:A burst signal contained in a color signal extracted by a burst gate 1 is turned into burst signals with every fH/2 by a filter 2. This burst signal is extracted only when the output of the filter 2 is higher than a prescribed level to impress it to a clip amplifier 6. An fH/2 sine wave generator 3 is driven by the output of the amplilier 6, and the output of the generator 3 receives half-wave rectification 4 and is supplied to a level detector 5. Owing to such an amplifier 6, the generator 3 is not driven when the output of the filter 2 is lower then the prescribed level. This can prevent a color signal having a deteriorated S/N as well as the erroneous decision when noises is effected.