| 摘要 |
PURPOSE:To simplify the configuration of a signal processing circuit by setting different detecting conditions of the focus signals between the odd and even fields of the continuous video screens. CONSTITUTION:The memory parts 22-A and 22-B are provided at an arithmetic control part 22 to store the focus signals of both even and off field series respectively. Then both memory parts extract the focus signals under the different conditions and compare these focus signals with each other for evaluation. Then the automatic focusing control is carried out with selection of the optimum conditions. For instance, the types of filters are changed between the even and odd fields for selection of a BPF which extracts a focus signal out of a video signal. At the same time, plural areas are prepared for extraction of the focus signal out of the video signal. Then the types of areas can be selected for selection of the focus signal extracting areas with mutual switch of areas between the even and odd fields. As a result, a smooth and inexpensive automatic focusing device is obtained. |
