| 摘要 |
A light diffusion sheet usable, for example, in backlight units, includes a transparent substrate layer, and a light diffusion layer overlaid on a front face of the substrate layer. The light diffusion layer includes resin beads and a resin binder, the resin beads being provided as monodisperse beads having a mean particle size of 1.5 μm or greater and 5 μm or less. A weight ratio of the monodisperse beads to the binder is 2.5 or greater and 3 or less, and an amount of the overlaid light diffusion layer is 3 g/m2 or greater and 10 g/m2 or less. An acrylic resin may be used as the substrate polymer of the monodisperse beads and binder. A coefficient of variation of particle size distribution of the monodisperse beads is preferably equal to or less than 0.2. Advantageously, a gravure coating method is employed for forming the light diffusion layer. |
| 主权项 |
1. A light diffusion sheet, comprising:
a transparent substrate layer, and a light diffusion layer overlaid on the front race side of said substrate layer, wherein said light diffusion layer excludes any pigment and includes beads uniformly distributed within a resin binder, said beads being monodisperse resin beads; wherein a front surface face side of the light diffusion layer away from the substrate layer has an uneven texture formed by protrusions of the monodisperse resin beads in the resin binder, the protrusions being distributed substantially evenly across said outer surface and achieving a substantially common height relative to spaces along the outer surface between the protruding monodisperse resin beads; wherein said substantially even distribution and substantially common height of the protrusions is achieved by using (i) only monodisperse resin beads having a mean particle size of 1.5 μm or greater and less than 5 μm (ii) a coefficient of variation of particle size distribution among said monodisperse resin beads that is equal to or less than 0.1, (iii) a weight ratio of the monodisperse resin beads to the binder that is 2.5 or rater and 3 or less, and (iv) an amount of the overlaid light diffusion layer that is 3 g/m2 or greater and 4.8 g/m2 or less; and by avoiding overlapping of the monodisperse resin beads with each other; wherein a material used for forming the monodisperse resin beads is from among the group of materials including acrylic resins, acrylonitrile resins, urethane based resins, vinyl chloride based resins, and polyamide, and a material used for forming the binder is from among the group of materials including acrylic resins, urethane based resin, polyester based resins, polyamide imide, and ultraviolet-curable resins; and wherein the light diffusion sheet has a haze value of 90.7% or greater. |
