FLAT LIGHT SOURCE DEVICE

• Main Authors: YAMAMOTO NAOYUKI, NIIDA HIDENORI, BETSUSHIBA NORIYUKI, FURUNOMA TAKAAKI, TOEDA MINORU
• Format: Patent
• Language: English
• Published: 15.12.2005
• 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 flat light source device having a light guide plate on which, the light emitted from a plurality of point-like light sources is incident, restraining generation of emission line, enhancing the utilization rate of the light emitted from the point-like light sources incident on the light guide plate. SOLUTION: The light guide plate has a guiding part 18 diffusing an incident light, and a plate-shaped light collection part 21 formed continuous to the guiding part 18 having a reflection part 20 formed on opposite side of an emission face 19. A plurality of prism-shaped protrusion 27 extending in a direction perpendicular to a virtual end face 21a of the light collection part 21 having a vertex angle of 135°to 150° are formed on the emission face 19. The guiding part 18 is formed into a symmetrical shape widening from light incident side toward the light collection part 21, and the angle between both side faces of the guiding part and a face orthogonal to the virtual end face 21a is 15°to 45°. A plurality of V-shaped grooves 22b extending in thickness direction of the light guide plate 14 are formed in the guiding part 18. The vertex angle α of the V-shaped groove is 60°to 90°, and the ratio of the width of an open end M to the pitch P of adjacent V-shaped groove 22b M/P is 0.3 to 0.7. COPYRIGHT: (C)2006,JPO&NCIPI