VARIFOCAL LENS HAVING AUTOMATED FOCUS CORRECTION MECHANISM, AUTOMATED FOCUS CORRECTION METHOD, AND PROJECTOR

摘要

PROBLEM TO BE SOLVED: To provide a varifocal lens capable of automatically adjusting a focus in correspondence with a zoom ratio with a simple configuration, and a projector equipped with the varifocal lens for its projection lens.;SOLUTION: An angle of the zoom lens of a varifocal lens type projection lens 10 of the projector that is operated with a zoom lever 21 is calculated by an angle sensor 22 for the zoom, and the present angle of the focus lens is calculated by an angle sensor 24 for the focus. Based on the calculation result of a quadratic expression read from the zoom/focus correlation control part 28 at the focus lens adjustment angle calculation part 27, the focus lens correspondence angle corresponding to the present zoom angle is calculated, an adjustment value from the present angle of the focus lens is calculated, and the angle is corrected by rotating a focus lens driving motor 30 in the focus lens driving circuit 29.;COPYRIGHT: (C)2008,JPO&INPIT