Title:
PANEL LIGHT SOURCE DEVICE
Document Type and Number:
Japanese Patent JPH03245123
Kind Code:
A
Abstract:
PURPOSE:To obtain uniform panel luminance at the direction remote from the tube axis of a light source by providing a luminous flux dispersing member having the shape to increase the reflection of the part corresponding to the tube axis of the light source and to increase transmitted light the further form the tube axis between the light source and a light receiving and diffusing plate along the tube axis of the light source. CONSTITUTION:The light receiving and diffusing plate 3 is disposed atop a reflecting box 2 which internally houses the light source 1. The luminous flux dispersing member 4 consisting of a transparent material, such as acryl or polycarbonte, is disposed between the light source 1 and the light receiving and diffusing plate 3 along the tube axis of the light source 1. The luminous flux dispersing member 4 is formed to the shape with which the part corresponding to the tube axis of the light source 1 has nearly 90 deg. angle with the surface of the light receiving and diffusing plate 3 to take the angle larger than the critical angle determined by the material of the luminous flux dispersing member 4 and to cause nearly the total reflection. This member is thus formed in the curved surface shape approximated in parallel to the plane of the light receiving and diffusing plate 3 the furtherer from the tube axis of the light source 1. The panel light source uniform over the entire surface of the diffusing plate is obtd. in this way.
Inventors:
KOBAYASHI AKIRA
SANO TORU
SANO TORU
Application Number:
JP4100390A
Publication Date:
October 31, 1991
Filing Date:
February 23, 1990
Export Citation:
Assignee:
HITACHI LTD
International Classes:
G02F1/1335; F21S2/00; F21V5/02; G02F1/13357; G09F9/00; (IPC1-7): F21S1/00; F21V5/02; G02F1/1335; G09F9/00
Attorney, Agent or Firm:
Katsuo Ogawa (1 person outside)