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US 8,542,443 B2Granted
Light reflector and planar light source device
AssigneeYupo Corporation
InventorsTakahiko Ueda, Hiroshi Koyama
Life of this patent
Estimating the term…
Abstract
A light reflector of which the bidirectional reflectance R1 is from 90 to 120% when the light entrance angle is 15° and the light acceptance angle is 0°, and the bidirectional reflectance R2 is from 85 to 110% when the light entrance angle is 75° and the light acceptance angle is 0°. The light reflector has high reflectivity, and attains brightness improvement even in underlight-type backlights.
Claims13
A light reflector, comprising:
- a substrate layer comprising a polyolefinic resin and a filler and stretched in at least one direction;
- and
- a light-diffusive layer including a filler in a concentration of from 45 to 70% by weight,
- wherein the substrate layer has a bidirectional reflectance R1 which is from 90 to 120% with respect to a bidirectional reflectance of a ceramic standard white plate, when a light entrance angle is 15° and a light acceptance angle is 0°, the substrate layer has a bidirectional reflectance R2 which is from 85 to 110% with respect to a bidirectional reflectance of a ceramic standard white plate, when the light entrance angle is 75° and the light acceptance angle is 0°, the light entrance angle and the light acceptance angle are angles with respect to a normal line direction of a surface to which light is applied, and the filler in the light-diffusive layer comprises at least one material selected from the group consisting of an inorganic filler having a mean particle size of from 0.2 to 0.7 μm and an organic filler having a mean dispersed particle size of from 0.2 to 0.7 μm.
1 more element
Dependencies are inferred from the claim text.