| 摘要 |
PURPOSE:To expand the discrimination available range and to improve the stability by constituting the titled circuit by the 1st monostable multivibrator, the 2nd monostable multivibrator and a latch circuit triggered by the 1st multivi brator to latch an output of the 2nd multivibrator. CONSTITUTION:A vertical synchronizing signal V and a horizontal synchronizing signal H are separated by a synchronizing separator circuit 2. The horizontal synchronizing signal H triggers the monostable multivibrator 4 and the vertical synchronizing signal V triggers the monostable multivibrator 5. A latch circuit 6 is triggered by the leading of an output signal of the monostable multivibrator 5 to latch an output D or F of the monostable multivibrator 4. When a video signal to the input terminal 1 is an odd number order of field, an L level output is obtained from the latch circuit 6 and when an even order number of field, an H level output is obtained from the latch circuit 6. Thus, whether the odd order or the even order number of field is discriminated depending whether the output of the latch circuit 6 i at L or H level.
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