Spread illuminating apparatus

• Main Author: AKAOKA HIROKI
• Format: Patent
• Language: English
• Published: 08.10.2002
• Edition: 7
• Subjects: BLASTING; FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMSTHEREOF; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21Sand F21V, RELATING TO THEFORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THELIGHT EMITTED; LIGHTING; MECHANICAL ENGINEERING; NON-PORTABLE LIGHTING DEVICES; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHERARTICLES, NOT OTHERWISE PROVIDED FOR; SYSTEMS THEREOF; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLEEXTERIORS; WEAPONS

In a spread illuminating apparatus including a transparent substrate which has a light reflection pattern with grooves formed to be inclined with respect to an optical axis of a light source, an optical path conversion means comprising grooves and flat portions is formed on a side surface of a light conductive member, where the depth of the grooves increases in proportion to the increase in distance from either of spot-like light sources toward a deepest groove formed at a predetermined position. The deepest groove is formed at a position off the center of the light conductive member by a predetermined distance toward either of the spot-like light sources, whereby the distribution of the amount of light emitted from the light conductive member toward the transparent substrate can be appropriately modified so as to level off the unevenness in brightness on the screen.