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:
May. 19, 2009
Filed:
Nov. 01, 2005
Yasufumi Ogawa, Chiba, JP;
Takaaki Iwaki, Tokyo, JP;
Hiroaki Uchino, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
A rear projection type display apparatus is disclosed wherein image light reflected upon entrance thereof into a Fresnel lens sheet of the reflection type provided on a transmission type screen is suppressed from making stray light. A Fresnel lens sheet for converting incident light incoming at an incident angle within a predetermined angular range into parallel light includes a plurality of prisms arrayed on the light entrance face of a substrate. Each prism has a refracting face for refracting the incident light and a reflecting face for reflecting the refracted light from the refracting face toward the emergence face of the substrate. At least some of the prisms are configured such that the angle of a perpendicular to the refracting face with respect to a perpendicular to the emergence face is smaller than the incident angle at the position of the prism.