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:
Jun. 06, 2006
Filed:
Nov. 24, 2004
Hildegard Ebbesmeier, Schweppenhausen, DE;
Hildegard Ebbesmeier, Schweppenhausen, DE;
Jos. Schneider Optische Werke GmbH, Bad Kreuznach, DE;
Abstract
A projection lens with a short focal length and high initial aperture is proposed. Such projection lenses are used, for example, in cinema projection. The projection lens is configured such that the sum of the overall length and the back focus () is between 2.8 times and 4.5 times the total focal length f'. The entrance pupil is at a distance of between 100 mm and 300 mm from the last lens surface (), which faces the illuminating mirror. The minimum stop number k of the projection lens is 1.7, and the projection lens is therefore also suitable for illuminating mirrors with a high aperture angle (of up to 17°).