The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 24, 1998
Filed:
May. 17, 1996
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An image magnification control device for a camera having a photographic lens. A distance 'X0' between a rear focal point of said photographic lens and an image taking plane of the camera is detected. Additionally, a defocusing amount 'dx' corresponding to a distance between the image taking plane and a surface on which an image is formed by the photographic lens is detected. A magnification ratio .gamma. of a control focal length 'f1' required to maintain an image magnification to a present focal length 'f0', that is based on the distance 'X0' and the defocus amount 'dx' is then calculated in accordance with a predetermined equation. Thereafter, an amount to drive the photographic lens to maintain the image magnification, based on the magnification ratio .gamma. is calculated, and the photographic lens is driven to change a focal length of the photographic lens.