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:
Dec. 23, 1980
Filed:
Dec. 07, 1978
William B Wetherell, Stoneham, MA (US);
David A Womble, Lunenberg, MA (US);
Itek Corporation, Lexington, MA (US);
Abstract
A compact, all-reflecting optical system for viewing distant objects. The system comprises a negative convex secondary mirror placed between a positive concave primary mirror and a positive concave tertiary mirror. The system has an eccentric field of view in that the field of view lies entirely on one side of the optical axis, and because of this, the light travelling from the object to the image will pass entirely outside the secondary mirror, both when entering the system and when travelling from the tertiary mirror to the image. Accordingly, with the present invention, there is no central obstruction and no consequent restriction on field of view and power distribution between mirrors as is found in prior art all-reflecting systems.