LIGHT GUIDE PLATE

• Main Authors: YAMAMOTO NAOYUKI, NIIDA HIDENORI, BETSUSHIBA NORIYUKI, FURUNOMA TAKAAKI, TOEDA MINORU
• Format: Patent
• Language: English
• Published: 22.12.2005
• Edition: 7
• Subjects: BLASTING; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMSTHEREOF; 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-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHERARTICLES, NOT OTHERWISE PROVIDED FOR; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; WEAPONS

PROBLEM TO BE SOLVED: To provide a light guide plate enhancing brightness at the center of a screen while securing evenness of brightness, in a side light type plane light source device. SOLUTION: The light guide plate 15, formed in a flat plate shape, converts the light incident from an incident face 15a into a place light and irradiates it from a light-irradiating face 19. The light-irradiating face 19 is provided with prism-shaped projecting strips 21 with an apical angle of 80° to 150° and a plurality of grooves 20 extended in a direction crossing an extending direction of the projecting strips on a face opposite to the light-irradiating face 19 formed in a cross section of a right triangle with its slope to be a light-incident face 15a side. Each groove 20 is formed to satisfy: Di=Do+(De-Do)×(Li/Le)N, provided that a depth of the groove nearest to the light-incident face 15a is Do, that of the one farthest is De, a depth of the i-th groove from the light-incident face is Di, a distance to the i-th groove is Li, and a length of the light guide plate is Le, an order N satisfies 1.4 to 1.8. COPYRIGHT: (C)2006,JPO&NCIPI