| 摘要 |
<p>PURPOSE:To attain accurate discrimination without being affected by noise by deciding a signal as a high-definition TV signal only when the detection pulse of a frame synchronizing signal is detected consecutively for a prescribed time. CONSTITUTION:One UP-count pulse (b) is given to the gate 11 of two AND gates 11, 12 for one frame in the reception of an HDTV signal and two DOWN- count pulses (e) are inputted to the other gate 12. Since the AND gate 12 is set by a decoder output Q0 only when the count of the counter 13 is logic '1', the counter 13 repeats the state of counts '0', '1'. Thus, a discrimination output terminal 15 is kept to the state of '0' and it is discriminated to be the reception state of the HDTV signal.</p> |
