| 摘要 |
<p>The television signal transcoder is fitted between the high frequency video stage and the convergence matrix of a receiver so that a SECAM television receiver can accept NTSC signals. It comprises an emitter-follower circuit (5) connected to the high frequency video stage of the television receiver or, as shown in figure 1, to a magnetic tape video recorder with four magnetic heads (A, B, C, D) giving three video signals and one sound signal. The emitter-follower circuit (5) can separate the brightness component (6) of the video signals (4) from the colour component (7). The brightness component (6) is applied, after passing through a filter (8), to the cathode (11) and to the convergence matrix (M) of the picture tube (12). A pass-band filter (16) modifies the colour component (7) which is then applied, after passing through a stabilizing amplifier (18) and two demodulators (24, 25) to the convergence matrix (M). The demodulators (24, 25) are also supplied with the video signals (4) after various modifications.</p> |
