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:
Aug. 09, 1983
Filed:
Feb. 25, 1981
Iain A Neil, Glasgow, GB;
Barr & Stroud Limited, Glasgow, GB;
Abstract
An afocal refractor telescope (10) is formed by a fixed focus achromatic objective system (11) and a fixed focus eyepiece system (12) aligned on a common optical axis (13), the objective system (11) being formed by two lens elements (C, D) and the eyepiece system (12) being formed by two lens elements (A, B), each of the four lens elements (A, B, C, D) being made of a material which has a useful spectral bandpass in the infrared wavelength region, and having refractive surfaces (1,2,3,4,5,6,7,8) intercepting the optical axis (13) which are substantially spherical, lens element (c), which is proximal the eyepiece system (12) being color corrective, with a V-value not less than 120, negatively powered and having a lower refractive index than lens element (D) which is positively powered. Conveniently lens element (C) is made of Chalcogenide glass and each of lens elements (A, B and D) is made of germanium.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile