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:
Oct. 06, 1992
Filed:
Apr. 09, 1991
Alan D Kathman, Madison, AL (US);
Daniel M Brown, Madison, AL (US);
Toledyne Industries, Inc., Los Angeles, CA (US);
Abstract
In accordance with the present invention, a BOE-corrected, off-axis image forming apparatus is disclosed. The apparatus has a first stage with a primary reflective element disposed to reflect light incident from an entrance pupil of the apparatus and form a real image at an intermediate image plane, and a second stage located off-axis with respect to the first stage. The second stage is defined by a secondary reflective and/or refractive assembly which re-images light from the intermediate image plane to a final image plane. A binary optical element (BOE), which has higher-order optical characteristics for providing aspheric correction but extremely low optical power, is provided in one of the stages for correcting aberrations introduced by the other optical elements in the apparatus. The BOE contributes no more than about 3% of the optical power provided by the stage which contains the BOE.