| 摘要 |
PURPOSE:To improve focusing performance, to reduce cost and to attain miniaturization by altering the frequency characteristic of a band pass filter for plural times within one field period. CONSTITUTION:This device is provided with a variable band pass filter(BPF) 1 which can change the frequency characteristic, a change over switch 2 distributing the output, multiple detectors 31-36 and a control circuit 4. Then, variable BPF 1 is switched by the horizontal synchronous period of a video signal and it is used. Namely, multiple frequency characteristics are obtained in one field period of the outputs from the detectors by time-divisionally using one BPF 1. Thus, the outputs of the detectors having various BPF characteristics can simultaneously be generated in the vertical synchronous period and a detection output characteristic similar to that of the detector having private BPF can be obtained by switching and using BPF 31-36 by the time division of the horizontal synchronous period. |
