| 摘要 |
PURPOSE:To attain smooth lens driving corresponding to the image moving speed of a subject by computing a lens driving speed up to a focusing position as specified at the end of next predictive storage and arithmetic, then driving a photographic lens. CONSTITUTION:This automatic focus adjusting device computes a defocusing quantity by a microcomputer 13 by using a CCD sensor (distance sensor) 6 to detect a focus, then drives the photographic lens 1. At the end of next predictive storage and arithmetic, the computer 13 computes the lens driving speed at which the lens 1 is driven to the focusing position from an equation VL =(VH.t+DF)/t and drives the lens 1. Here, VH is the image plane moving speed or predicted image plane moving speed of a subject, (t) is a predictive storage and arithmetic time, and DF is the defocusing quantity at the end of current arithmetic. The time (t) is calculated based upon the latest storage and arithmetic time of plural storage and arithmetic time data which are obtained so far. Consequently, the lens is not stopped while a subject is followed up and the smooth lens driving is enabled. |
