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:
May. 26, 1992
Filed:
May. 31, 1991
Fumio Haibara, Akishima, JP;
Konica Corporation, Tokyo, JP;
Abstract
In a method for compensating a variable image magnification in an optical zoom system, a magnified image is formed on a focal surface by projecting a document image through a projection lens and onto mirrors provided to an optical path length adjusting device. The position of the projection lens and the optical path length adjusting device are compensated so that an actual image magnification is the same as a selected nominal image magnification. An optional nominal magnification within a predetermined variable magnification range is selected. At least one of the projection lens and the variable optical path length adjusting device is moved so as to be in focus and then an actual image magnification at a position where the projection lens is in focus is measured. An actual focal length of the projection lens is calculated from the measured magnification according to equations with respect to magnification, focal length, principal points and so on. Each compensating position of the projection lens and the optical path length adjusting device in accordance with the selected magnification is determined, based on the calculated focal length and the optional nominal magnification.