| 摘要 |
PURPOSE:To obtain the compatibility between a TV received signal of standard system and that of TV system which employs a horizontal scanning frequency about (n)-fold as high as that of the standard system, by controlling the gain of the signal of the standard system so as to have the same luminance on a display screen, as for both received signals. CONSTITUTION:A signal converting circuit 3 receives the TV signal of a standard system and increases its horizontal scanning frequency (n) times. Then, the circuit 3 stores the TV signal of the standard signal for a one-horizontal-line period, reads the stored signal only once at a speed (n)-fold as fast as that in the storage, and performs signal conversion. On the other hand, the received signal of another TV system which has a horizontal scanning frequency about (n)-fold as high as that of the standard system is inputted from an input terminal 10 to a demodulating circuit 11, and while its demodulation output is sent to a video amplifying circuit 5 through a switch 15, a signal processed by frequency separation 12 is sent to a vertical deflection circuit 7 and a horizontal deflection circuit 9 through switches 13 and 14' respectively. Then, the gain of the signal of the standard system is brought under control 4 so as to have equal luminance on a display screen as for both the system. |
