Light reflector and planar light source device
AssigneeYupo Corporation
InventorsTakahiko Ueda, Hiroshi Koyama
Life of this patent
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Abstract
A light reflector including a laminate film having a light-diffusive layer on one surface of a substrate layer, wherein the surface roughness index of the light-reflective surface is at least 1, the reflectance thereof is at least 95%, and the regular reflectance thereof is at most 3%. The light reflector has higher brightness and higher reflectivity.
Claims14
A light reflector which comprises a laminate film having a light-diffusive layer (B) on one surface of a substrate layer (A), wherein the surface roughness index Z, as represented by the following formula (1), of the light-reflective surface of the light reflector is at least 1, the reflectance R1 thereof at a wavelength of 550 nm is at least 95%, and the regular reflectance R2 thereof, as represented by the following formula (2), at a wavelength of 550 nm is at most 3%:
- Surface roughness index Z=(surface area, Sf, of light-reflective surface)/(volume, V, of the projections of light-reflective surface) (1)
- Regular Reflectance R2 =(reflectance R1)−(diffuse reflectance R3) (2)
- wherein R3 is a diffuse reflectance at a wavelength of 550 nm.
Dependencies are inferred from the claim text.