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:
Jan. 17, 2006
Filed:
Nov. 10, 2004
Tomoyoshi Yamashita, Kanagawa, JP;
Issei Chiba, Kanagawa, JP;
Tomoyoshi Yamashita, Kanagawa, JP;
Issei Chiba, Kanagawa, JP;
Mitsubishi Rayon Co., Ltd., Tokyo, JP;
Abstract
A light-source device having a light guide () for guiding light emitted from a primary light source and emitting light obliquely from a light emission face () thereof, and a light deflecting device () disposed so as to be adjacent to the light emission face. Plural elongated prisms are arranged in parallel to one another at a light incident surface () of the light deflecting device. Virtual elongated prisms (I) each having a vertical angle θ of 50 to 70° arranged in the same arrangement pitch as the elongated prisms are assumed so that the peak emission light in the light emission distribution of light emitted from the light emission face is incident on one virtual prism face of the virtual elongated prism, internally totally reflected by another virtual prism face and then emitted in a desired direction from a light emission surface () of the light deflecting device. A prism face of each elongated prism at the far side from the primary light source is designed to have a convex surface shape with respect to the shape of the virtual elongated prism. The value (r/P) of the radius of curvature r normalized by the arrangement pitch P is equal to 7 to 30, and the ratio (d/P) of the maximum distance between the convex-surface-shaped prism face of the elongated prism and the virtual prism face to the arrangement pitch P is equal to 0.05 to 5%.