OPTICAL SHEET, SURFACE LIGHT SOURCE DEVICE AND TRANSMISSION TYPE DISPLAY DEVICE

摘要

There is provided an optical sheet which can prevent problems when it is superimposed on another member. The optical sheet includes: a sheet-like base layer; a light control layer having unit shaped elements arranged in a direction parallel to a sheet surface of the base layer; and a light diffusing layer disposed between the base layer and the light control layer. The light diffusing layer includes a binder resin portion and particles dispersed in the binder resin portion. The particles in the binder resin portion include a single particle and an aggregate formed of aggregated single particles.

主权项

1. An optical sheet comprising:
a sheet-like base layer; a light control layer having unit shaped elements arranged in a direction parallel to a sheet plane of the base layer; and a light diffusing layer disposed between the base layer and the light control layer, wherein the light diffusing layer has a binder resin portion and particles dispersed in the binder resin portion, wherein the particles contained in the binder resin portion include an aggregate of aggregated single particles, wherein a surface, on a side of the light control layer, of the light diffusing layer is a rough surface having raised portions, wherein a refractive index of the binder resin portion of the light diffusing layer differs from a refractive index of a layer adjacent, from a side of the light control layer, to the light diffusing layer, and wherein the average value of radii of curvature at tops of the raised portions is lower than the average value of radii of granulated substances, the granulated substances being formed of the aggregate or the single particles and existing in the light diffusing layer.