| 摘要 |
PURPOSE:To reduce a malfunction due to an influence of an end section of a sampling area by using an added value of focusing values in plural sampling areas overlapped in a central section of screen as evaluation value. CONSTITUTION:A synchronous pulse generating circuit 26 conducts out a vertical blanking pulse V and a horizontal blanking pulse H and a color subcarrier C to drive an image pickup element. Only a luminance signal in a sampling area set by a sampling area setting circuit 28 among the luminance signals obtained by the image pickup element is sampled. A sampling output is integrated every one field in an integration circuit 5. The output from the circuit 5 is outputted as a focusing value and latched by hold circuits 6, 7. A comparison circuit 10 compares evaluation values of a present field and a preceding field to drive a focusing motor 12.
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