Title:
導光板、導光板ユニットおよび面状照明装置
Document Type and Number:
Japanese Patent JP4762217
Kind Code:
B2
Abstract:
The light guide plate includes a light exit plane, two light entrance planes, two symmetrical inclined rear planes increasingly distanced from the light exit plane from the two light entrance planes toward a center of the light exit plane, a curved portion joining the two inclined rear planes and scattering particles for scattering light travelling inside the light guide plate. The light guide plate satisfies given ranges set for a length between the two light entrance planes, a thickness of each of the two light entrance planes, a thickness at the center of the curved portion, a radius of curvature thereof, tapers of the inclined rear planes, and a particle diameter and a density of the scattering particles, and conditions that a light use efficiency be 55 % or greater and that a middle-high ratio represented by the brightness distribution at the light exit plane be greater than 0% and not greater than 25 %.
Inventors:
Takamitsu Okumura
Application Number:
JP2007256628A
Publication Date:
August 31, 2011
Filing Date:
September 28, 2007
Export Citation:
Assignee:
FUJIFILM Corporation
International Classes:
F21S2/00; F21V8/00; F21Y101/02
Domestic Patent References:
| JP8094851A | ||||
| JP10332941A | ||||
| JP7110408A |
Foreign References:
| WO2007020966A1 |
Attorney, Agent or Firm:
Nozomi Watanabe
Haruko Sanwa
Haruko Sanwa