SURFACE LIGHT SOURCE UNIT

• Main Author: SHIMURA TAKASHI
• Format: Patent
• Language: English
• Published: 16.02.2001
• Edition: 7
• Subjects: BLASTING; 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; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHERARTICLES, NOT OTHERWISE PROVIDED FOR; WEAPONS

PROBLEM TO BE SOLVED: To obtain a surface light source of an edge light system which is uniform in luminance. SOLUTION: A light guide plate 11, which is a planar member made of a translucent member and densely forms irregular reflection parts at positions farther from a light source on a lower surface, is constituted of a light emitting part 12 in which an upper surface 12a is provided as a light emitting surface, and a plane shape is a substantially right-angled quadrilateral and a light source part 13 which is continuous to a virtual side surface (m) on an LED 20 side and extends from the light emitting surface part 12 to the LED 20 side. Within the light source part 13, a reflection refracting part 16 constituted of through-holes or non-through-holes having a reflection refracting surface 16b, in which thickness direction cross section of the light guide plate 11 is vertical and plane direction cross section is inclined with respect to the LED 20 is provided so as to be opposed to the LED 20. On both side surfaces 13d on the LED 20 side of the light source part 13, irregular reflection parts 15, constituted of a plurality of grooves of substantially circular, arc cross-sectional in shapes substantially parallel in the thickness direction of the light guide plate 11 are provided. The irregular reflection parts 15 are provided so that the area ratio is larger, the farther away the irregular reflection parts are from the light source.