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:
Oct. 19, 1999
Filed:
May. 13, 1998
Ian Duguid Mearns, St Asaph, GB;
Pilkington PE Limited, St Asaph, GB;
Abstract
A dual field optical system [20] comprises an objective [A, B,] which forms an intermediate image [10] and a relay [E, F,] which transfers radiation to a focal plane [12]. The objective [A, B] comprises a primary mirror [A] and a secondary mirror [B] arranged in the form of a Cassegrain system and is rendered dual-field by the provision of an alternative primary mirror [A.sup.1 ] which is axially movable between in-use and out-of-use positions. The primary mirror [A] forms part of a housing [J] for a linear actuator [15] which is connected by co-axial rods [14] to the alternative primary mirror [A.sup.1 ] so that the system is both compact and of low mass due to symmetry.