发明授权
- 专利标题: Surface illuminant device emitting light in multiple directions in concentrative manner
- 专利标题(中): 表面照明装置以多个方向集中发光
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申请号: US09401806申请日: 1999-09-22
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公开(公告)号: US06357888B1公开(公告)日: 2002-03-19
- 发明人: Manabu Takata , Takayoshi Tanabe
- 申请人: Manabu Takata , Takayoshi Tanabe
- 优先权: JP10-269257 19980924; JP11-172473 19990618
- 主分类号: F21V704
- IPC分类号: F21V704
摘要:
A surface illuminant device includes a surface illuminant having a light distribution characteristic with no directivity relative to specific directions, and a prism sheet having a plurality of prisms each having a predetermined apical angle. The prism sheet is placed on the light emission side of the surface illuminant. One side of the prism sheet on which a plurality of prisms are placed is opposite to the light emission side of the surface illuminant. Accordingly, light can be emitted in a plurality of specific directions in concentrative manner to enhance luminance in that plurality of directions. Further, the surface illuminant device includes an optical sheet which condenses the incident light. In the luminance distribution (light distribution characteristic) thus obtained, the luminance gently decreases in the vicinity of the directions in which light is emitted in concentrative manner.