Scan times (倍 走 査) television receivers

摘要

PURPOSE:To prevent such deterioration in picture quality that a slanting line is stepwise, by attenuating an area where an interpolated signal has high frequency components vertically and horizontally at the same time. CONSTITUTION:A video signal SNI of double horizontal frequency which contains two successive signals of each scanning line of a video signal at every period 1H/2 is obtained from a changeover switch 5 and supplied to a spatial filter 28. The attenuator 28b of the filter 28 subtracts a signal passed through a delay line 38a from the signal SNI to obtain an area where the signal SNI has a high frequency component vertically and this is supplied to an LPF 28g through a level regulator 28e to obtain an area where the signal has a high frequency component vertically and a low frequency component horizontally, thereby supplying it to an adder 28i. Further, an adder 28c obtains an area where the signal SNI has a low frequency component vertically and it is supplied to the adder 28i after a time adjustment by a delay line 28h. Therefore, the adder 28i outputs the signal SNI attenuated where the vertical high frequency component and horizontal high frequency component are present.