| 摘要 |
PURPOSE:To dispense with sub hue adjustment by constituting the characteristic of a lug/lead filter in an APC (color synchronizing processing) loop of a complete integration type and an incomplete integration type, and switching the characteristic when the APC loop is locked and unlocked. CONSTITUTION:Only a burst signal in a digital chroma signal outputted from a multiplier 1 is written on memory 2. A control part 7 performs feedback control so that burst data with specific address in the memory 2 can go to specific phase data in the locked state of the APC loop, and phase leading degree data is calculated from the phase data in the memory 2, and it is stored in an APC register 10. Lug/lead processing is also included in such processing, and the characteristic is switched to the complete integration type one in which a gain for DC displays infinite frequency characteristic when the APC loop is locked, and to the incomplete integration type one in which the gain displays finite frequency characteristic when the APC loop is unlocked. In this way, the APC loop always returns to the locked state even when it is unlocked, which requires no sub fue adjustment. |
