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:
Mar. 29, 2011
Filed:
Sep. 28, 2006
Yasuhiro Daiku, Iruma, JP;
Yasuhiro Daiku, Iruma, JP;
Casio Computer Co., Ltd., Tokyo, JP;
Abstract
A surface light source includes a light guide unit which allows two linear polarized lights having polarized planes perpendicular to each other to alternately exit from an exit surface in a direction substantially parallel with a normal line of the exit surface. A retardation element is arranged to face the exit surface. The retardation element has λ/2 retardation portions which give a phase difference of a ½ wavelength between ordinary light and abnormal light, and a plurality of non-retardation portions having substantially no phase difference alternately formed in a direction along the exit surface. A lens array is provided to face the light guide unit. The lens array allows light which has been transmitted through a λ/2 retardation portion to exit in a first inclined exiting direction, and allows light which has been transmitted through a non-retardation portion to exit in a second inclined exiting direction.