Patent ID: 7697206

Claim:
A prism-integrated light-diffusing plate, comprising a prismatic portion formed of a plurality of prism-shaped protrusions provided on at least one surface of a light-diffusing sheet, said light diffusing sheet comprising a transparent resin material and a light-diffusing agent and having a thickness of 0.5 to 3 mm and a total light transmittance of 60 to 95%, wherein the light-diffusing agent is present in the form of particles having a mean particle size of 1 to 200 μm and/or present in the form of fibers having a length to diameter ratio (L/D) of 2 or more, the amount of the light-diffusing agent in the light diffusing sheet is 0.1 to 20 parts by mass on the basis of 100 parts by mass of the transparent resin material, and the light-diffusing agent is selected from the group consisting of a thermoplastic acrylic resin, a polystyrene resin, a cross-linked acrylic resin, a cross-linked polystyrene resin, a silicone resin, a fluorocarbon resin, silica, quartz, and combinations thereof, further provided that when light enters a surface opposite the surface having the prismatic portion in a direction perpendicular to the opposite surface, the ratio of intensity of transmitted light as measured in a direction 20° from the perpendicular direction to intensity of transmitted light as measured in the perpendicular direction i.e., a light-intensity distribution indicator, is 0.02 to 0.7.