Optical: systems and elements – Lens – With variable magnification
Patent
1994-07-05
1997-06-10
Epps, Georgia Y.
Optical: systems and elements
Lens
With variable magnification
359700, G02B 1514
Patent
active
056382170
ABSTRACT:
A lens control device for an inner focus lens system has a first lens group for zooming; a second lens group for focusing; a first zooming unit for controlling the second lens group for correcting the displacement of the focal plane resulting from the movement of the first lens group; a memory for memorizing the relative position of the second lens group to the first lens group in a zooming operation by the first zooming unit; a calculation unit for calculating the moving speed of the second lens group based on the memorized data, in order to maintain the focused in the course of movement of the first lens group; and a second zooming unit for controlling the second lens group according to the result of calculation. In this configuration, the positions of the focusing lens is memorized in a zooming operation from the telephoto side to the wide angle side, and, in the zooming operation from the wide angle side to the telephoto side, which is apt to generate a defocus, the focusing lens is controlled by the memorized data, in order to avoid generation of such defocus.
REFERENCES:
patent: 4697891 (1987-10-01), Kawai
patent: 4975724 (1990-12-01), Hirawawa et al.
patent: 5005956 (1991-04-01), Kaneda et al.
patent: 5027147 (1991-06-01), Kaneda
patent: 5038163 (1991-08-01), Hirasawa
patent: 5060001 (1991-10-01), Kaneda
patent: 5067802 (1991-11-01), Orino
patent: 5144491 (1992-09-01), Ushiro et al.
patent: 5164756 (1992-11-01), Hirawawa
patent: 5200860 (1993-04-01), Hirasawa et al.
patent: 5223981 (1993-06-01), Kaneda
patent: 5287223 (1994-02-01), Hirasawa
patent: 5323200 (1994-06-01), Hirasawa
patent: 5369461 (1994-11-01), Hirasawa et al.
patent: 5406345 (1995-04-01), Hirasawa
patent: 5455649 (1995-10-01), Yamada et al.
Hirasawa Masahide
Ouchi Toshimichi
Canon Kabushiki Kaisha
Epps Georgia Y.
Robbins Thomas
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