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:
Sep. 22, 1987
Filed:
Jan. 13, 1983
Iain A Neil, Bearsden, GB;
Barr & Stroud Limited, Glasgow, GB;
Abstract
A forward looking infrared optical system comprises a refractor telescope 20 in combination with a powered window and fold mirror arrangement 30. Arrangement 30 comprises a powered window element J with concentric spherical refractive surfaces having their common center of curvature on the common optical axis 19 where the latter is folded by the reflective surface 27 of the mirror element I. Because the window element J is powered it introduces significant spherical aberration and some color aberration to the system however telescope 20 provides compensation for such aberrations by being non-afocal and non-diffraction limited. This is achieved by the objective system 21 of the telescope 20 being telephoto and formed of two elements H,G of which H is positively powered and G is negatively powered and color corrective. The refractive surfaces of element G are each spherical whereas at least one refractive surface (15) of element H is aspheric. Element G is made of a material having a lower refractive index than that of element H.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile