| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the need for adjustment of respective receivers and to prevent a secular change in this blanking period control circuit that makes loopback and distorted image at both ends of a screen invisible in the normal mode of a wide television receiver. SOLUTION: Blanking is applied to a loopback/distorted image occurred on a screen with a blanking pulse E generated by an output of an OR circuit 16 receiving pulses C, D outputted from two counters 12, 13 counting a horizontal source oscillation pulse F of a horizontal source oscillation circuit 1 synchronously with a flyback pulse A so as to eliminate the need for adjustment of respective television receivers and to prevent a secular change. Furthermore, fine adjustment counters respectively in cascade connection to both the counters 12, 13 are used to count a color demodulation oscillating pulse for a color demodulation oscillation circuit to generate a fine-adjustment pulse thereby making a time width of the blanking pulse E accurate. |
