| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting system suitable for an image display device having a wide angle high reflectivity. SOLUTION: The image display device (10) is a particle flying type and powder transferring type display device sealing a particle group or a powdery fluid (13) between first and second substrates (11, 12), and displaying an image by applying an electric field for moving particles or a powdery fluid, which has the wide angle high reflectivity. A light guide plate (30) is made of a material with a refractive index of 1.4-1.6. The angleβof a second slope (35) of a prism (32) is 27 to 35 degrees. An emitting surface emits light having a peak angle where the luminous intensity becomes the maximum at an angle of 25 to 60 degrees to a normal line of the emitting surface to strongly irradiate the image display device diagonally. As a result, a user can see the image well from a normal line direction of a display screen, which can be seen better with higher contrast when diagonally seen from the light source side. COPYRIGHT: (C)2005,JPO&NCIPI |
