| 摘要 |
PURPOSE:To attain rapid and accurate focusing by approaching a focusing lens to a just focusing position while oscillating the lens so as to converge the lens on the just focusing position. CONSTITUTION:A prescribed high frequency component of a video signal S1 obtained from an image pickup means 7 is extracted as a focus voltage E and the focusing lens 1 is moved by a moving means 2 in the optical direction on the basis of the differential voltage DELTAE of the focus voltage between two points Tn, Tn+1 (n>=1) to execute focusing. The auto-focusing device is provided with a control means 3 for outputting a control signal S2 for moving the lens 1 in the optical axis direction while oscillating the lens 1 in a prescribed amplitude (h) on the basis of the differential voltage DELTAE and the control signal S2 is supplied to the moving means 2 to converge the lens 1 to the just focusing position. Consequently, rapid and accurate focusing can be attained. |
