| 摘要 |
PURPOSE:To obtain the automatic focus device in which focusing is attained even when an object is in existence on both sides of the screen by performing focus control by means of a mount-climbing method where a focus lens is moved up to a position at which a focus evaluation is maximized. CONSTITUTION:A window pulse generating circuit 7 generates a window pulse used to limit focus areas A-C in integration circuits 8-10. The integration circuit 8 integrates a digital video signal in the focus area A, the integration circuit 9 integrates a digital video signal in the focus area B, and the integration circuit 10 integrates a digital video signal in the focus area C, and a focusing evaluation value of each of the focus areas A-C is outputted to a microcomputer 11 at every field. The microcomputer 11 moves a focus lens 1 at the focusing evaluation value in the focus areas A-C to drive the focus lens 1 so as to be in compliance with a peak value of the focus evaluation value to at first detect. |
