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. 22, 1987
Filed:
Jul. 10, 1986
John M Palmer, Clwyd, GB;
Pilkington P.E. Limited, , GB;
Abstract
An apochromatic catadioptric lens is provided which can operate in the 3 to 5 and the 8 to 12 micron wavebands. The lens comprises a primary mirror having an opening and a Mangin secondary mirror for directing light of the required wavebands through the opening. In the light paths between the primary mirror and Mangin secondary mirror are a pair of refracting lens elements of optically transmissive materials different from each other and from that of the Mangin secondary mirror. Preferably, the Mangin secondary mirror is of germanium, the refracting lens element of the pair nearer the Mangin secondary mirror is of zinc sulphide and the refracting lens element of the pair further from the Mangin secondary mirror is of zinc selenide. The invention also extends to an afocal telescope of non-Galilean form incorporating such a lens.