VARI-FOCAL LENS CONTROLLER

摘要

PURPOSE:To enable sure and rapid variable driving operation by providing a focusing correction control means to prevent generation of an overload of a focusing driving means in a very close distance which is liable to arise when updating is executed from a long focal length side to short focal length side. CONSTITUTION:The focusing correction control means 11 calculates the amt. of correction with respect to the deviation in an imaging position upon receipt of the output from a means for detecting the position of a variable power lens group and means for detecting the position of a focusing lens group after driving of the variable lens group by a variable power driving means 16 and executes the focusing correction control to control the focusing driving means so as to drive the focusing lens group to the focusing position at said focal length. Said means first drives the focusing lens group by as much as the prescribed length to the infinite position side and executed the focusing correction control thereafter, if the focal length of the entire system is updated from the longest focal length side to the shortest focal length side. The deviation in the imaging position arising from the updating of the focal length of the entire system of the variable power optical system is thereby automatically corrected.