Title:
PLANAR LIGHT SOURCE DEVICE AND DISPLAY DEVICE
Document Type and Number:
WIPO Patent Application WO/2018/109978
Kind Code:
A1
Abstract:
A planar light source device has: a plurality of light emitting elements; a luminous flux control member including a first luminous flux control member which is a diffusing lens, a second luminous flux control member having a Fresnel structure, and a third luminous flux control member having a plurality of lens surfaces; and a diffusion member. When the focal distance of the first luminous flux control member is f, and the distance between a first central axis and an optical axis in the light emitting element separated farthest from the first central axis is d, the planar light source device satisfies –0.6 < d/f < 0. Also, when the width in the cross section including the central axis of the lens surface is w, the radius of curvature of the lens surface is R, and the distance between the diffusion member and the intersection point of the center line of the lens surface and the surface at the diffusion member side in the third luminous flux control member is t, the planar light source device satisfies 0 < w2/t < 0.85 and 0.4 < w/R < 1.4.
Inventors:
NAKAMURA MASATO
Application Number:
PCT/JP2017/029372
Publication Date:
June 21, 2018
Filing Date:
August 15, 2017
Export Citation:
Assignee:
ENPLAS CORP (JP)
International Classes:
F21S2/00; F21V3/00; F21V5/00; F21V5/02; F21V5/04; G02B3/00; G02B3/04; G02B3/06; G02B3/08; G02B5/02; F21Y115/10; G02B27/01
Foreign References:
| JPS64209U | 1989-01-05 | |||
| JP2007157686A | 2007-06-21 |
Attorney, Agent or Firm:
WASHIDA, Kimihito (JP)
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