EDGE LIGHT-TYPE LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an edge light-type lighting device allowing a person inside a room to feel excellent brightness.

SOLUTION: The edge light-type lighting device 7 includes: a substantially quadrangular light guide plate 1; a light source 2A arranged and installed on at least one side end face side of the light guide plate 1; a substantially quadrangular reflective film 3 arranged and installed on a reflecting face side opposite to a light exiting face of the light guide plate 1 by which light emitted from the light source 2A and incident on the side end face of the light guide plate 1 is emitted; and a substantially quadrangular light diffusion plate 6 arranged and installed on the light exiting face of the light guide plate 1. In the edge light-type lighting device, an irregular reflecting part which causes the light to be reflected irregularly is formed on the surface of the reflecting face of the light guide plate 1. On the outer surface of the light diffusion plate 6, a brightness A1in the vicinity of a certain side of the light diffusion plate 6, a brightness A2in the vicinity of a side opposite to the certain side, and a brightness B in the vicinity of a line drawn with a distance equal to two sides thereof opposite to each other satisfy formulas (1) and (2): formula (1) 1.2×A1≤B≤3.0×A1, and formula (2) 1.2×A2≤B≤3.0×A2.

COPYRIGHT: (C)2011,JPO&INPIT