| 摘要 |
PURPOSE:To attain focusing of multifarious objects by monitoring a level of an output signal of a horizontal and a vertical absolute value peak detection circuit and controlling 1st and 2nd switches in response to the level. CONSTITUTION:A signal inputted to a horizontal absolute value peak detection circuit 22 and a vertical absolute value peak detection circuit 23 is subjected to absolute value processing respectively, the peak value is detected over one field and the maximum value of a horizontal differentiating value for one field is inputted to a control section 25 and the maximum value of a vertical differentiating value for one field detected similarly is inputted to the control section 25. When the maximum value of the horizontal differentiating value in the control section 25 is larger (smaller) than a prescribed level, the 1st switch 16 is closed (opened) to activate (inactivate) a horizontal band pass filter 15. Moreover, when the maximum value of the vertical differentiating value in the control section 25 is larger (smaller) than a prescribed level, the 2nd switch 28 is closed (opened) to activate (inactivate) a vertical band pass filter 27. Thus, multifarious objects are focused independently of longitudinal and lateral line components. |
