Patent ID: 6501505
Filing Date: 2002-12-31
Classification: G02B,H04N

Abstract:
A TV lens attached to a TV camera, the TV lens comprising:a focus lens group; a zoom lens group; a master lens group; focus lens drive means for moving the focus lens group with a first motor; zoom lens drive means for moving the zoom lens group with a second motor; master lens drive means for moving the master lens group with a third motor; first focusing means for focusing the TV lens by controlling the focus lens drive means according to a focus evaluation value representing a sharpness of an image, the image being projected on an imaging plane of the TV camera by the TV lens, the focus evaluation value being produced from a video signal converted from the image; second focusing means for focusing the TV lens by controlling the master lens drive means according to the focus evaluation value; and control means for adjusting a flange back length of the TV lens by controlling the zoom lens drive means and the first and the second focusing means such that focusing of the TV lens by the first focusing means while the zoom lens group is placed at a telephoto side and focusing of the TV lens by the second focusing means while the zoom lens group is placed at a wide side are repeated alternately at least once.