To provide a surface light source device capable of improving simply uniformity of luminance by devising positional relationship of a point light source and a light diffusion member.
The surface light source device does not include any other emission center point on any of the four sides of a quadrangle having emission center points of prescribed four light sources 2 as an apex or in the region surrounded by the four sides, and has a first surface 5 facing the light sources 2 and a second surface 6 on the opposite side; and a light diffusion member 3, which emits light for every light source 2 emitted from each light source 2 in a diffused condition from the second surface 6, is arranged. Prescribed projections of pyramid shape are formed arranged in a row on the second surface 6 and the virtual bottom faces of the projections located on the second surface are constructed of a plurality of straight line bottom sides, and all these bottom sides have a torsional position relationship to the four sides and the diagonal lines of the quadrangle.
| JP2023133214 | DISPLAY DEVICE |
| JP2017004978 | ILLUMINATION PANEL |
| JP5210452 | LED unit and lighting equipment using it |
NAKIYAMA SHIGERU
| JP2009211990A | 2009-09-17 | |||
| JP2008305923A | 2008-12-18 | |||
| JP2009048995A | 2009-03-05 | |||
| JP2003045212A | 2003-02-14 |
| WO2007114158A1 | 2007-10-11 | |||
| WO2010010840A1 | 2010-01-28 |
伊藤 高英
大倉 奈緒子
玉利 房枝
畑中 芳実
鈴木 健之
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