Title:
SURFACE LIGHT SOURCE DEVICE AND ILLUMINANCE DISTRIBUTION ADJUSTMENT PLATE
Document Type and Number:
Japanese Patent JP2019061738
Kind Code:
A
Abstract:
To suppress illuminance unevenness in a light emission surface of a direct type surface light source device.SOLUTION: An illuminance distribution adjustment plate 40 of a surface light source device 20 includes a base material 41 where a plurality of light transmission holes 45 are formed. The base material has one or more compartment areas Aa. In the respective compartment areas, the compartment areas are further divided into a plurality of element areas Ab arranged regularly. A plurality of element areas include a plurality of first element areas Ab1 regularly arranged and a plurality of second element areas Ab2 regularly arranged. The respective first element areas have square shapes in a planar view. The respective second element areas have octagonal shapes in a planar view. In each of the first element areas, one first light transmission hole 47 is formed; in each of the second element areas, one second light transmission hole 49 is formed. Aperture ratio by the second light transmission hole in one second element area arbitrarily selected is equal to aperture ratio or below by the second light transmission hole in another arbitrary second element area away from a center Oof the compartment areas rather than the second element area.SELECTED DRAWING: Figure 1
Inventors:
NISHIKAWA MARIE
TANIGUCHI YUKIO
TANIGUCHI YUKIO
Application Number:
JP2017182909A
Publication Date:
April 18, 2019
Filing Date:
September 22, 2017
Export Citation:
Assignee:
DAINIPPON PRINTING CO LTD
International Classes:
F21S2/00; F21V11/14; G02F1/13357
Attorney, Agent or Firm:
Hiroyuki Nagai
Yukitaka Nakamura
Yasukazu Sato
Satoru Asakura
Yukihiro Hotta
Yasumoto Yasumoto
Yukitaka Nakamura
Yasukazu Sato
Satoru Asakura
Yukihiro Hotta
Yasumoto Yasumoto