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:
Jan. 22, 1985
Filed:
Dec. 29, 1983
Michael O Lidwell, Glasgow, GB;
Barr & Stroud Limited, Glasgow, GB;
Abstract
A telescope objective system (10) is formed by a primary lens having a single lens element (A) aligned on a common optical axis (11) with a secondary lens having two lens elements (B,C) the shape and power distribution of lens elements (A,B,C) being such as to compensate for monochromatic aberration of the system, each lens element (A,B,C) being made of a material which has a useful spectral bandpass in the infrared wavelength region and lens elements (B,C) having refractive surfaces (16, 15, 14, 13) intercepting the optical axis (11) which are substantially spherical, the system having a planar image surface (11) and an effective focal length greater than the axial distance between the image surface (11) and the distal refractive surface (18) formed by the primary lens element (A). Primary lens element (A) is positively powered and made of germanium and at least one of the secondary lens elements (B,C) is made of a Chalcogenidae glass such that the system (10) is achromatic in the infrared wavelength region. Conveniently lens element (B) is made of Chalcogenide glass and is negatively powered. Lens element (C) may be negatively powered and made of germanium, or positively powered and made of a Chalcogenide glass.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile