| 摘要 |
PURPOSE:To keep a focusing state even while zooming is performed by controlling the driving speed of a focusing lens including an image-formation compensation function. CONSTITUTION:The autofocusing device is so constituted that the driving speed of the focusing lens 3 including the image-formation compensation function is controlled based on the information on the focal distance of a photographic lens, the information on focus detection and the information on the elapsed time related to a focus detection cycle while driving a variator lens 2 for variable magnification. Therefore, the control of a speed approximate to an ideal driving speed can be accomplished even in the case of not depending on the information on focus detection so much. Thus, the focusing state can be always kept even while zooming is performed without using a linking member such as a cam ring. |
