公开(公告)号：US07156547B2

公开(公告)日：2007-01-02

申请号：US10376293

申请日：2003-03-03

申请人： Yasumaro Toshima ,  Masashi Takai ,  Hideharu Nagami

发明人： Yasumaro Toshima ,  Masashi Takai ,  Hideharu Nagami

IPC分类号： F21V8/00

CPC分类号： G02B6/0051 ,  F21V3/04 ,  F21V5/00 ,  G02B6/0053 ,  G02B6/0065

摘要： A light diffusive sheet of the present invention comprises a transparent polymer sheet provided with a light diffusion layer 3 on one side and an uneven surface 4a having arithmetical mean deviation of 0.5 μm or less and mean spacing of 80 μm or narrower on the opposite side. Such an uneven surface can be made by forming a backcoat layer 4 including a mixture of particles having particular mean diameters in a particular proportion to a binder resin on the transparent polymer sheet. An area light source element 7 of the present invention is produced by laminating a prism sheet 6 on a light guide plate 5 so that the prism surface 61 of the prism sheet 6 is opposed to the light-emitting surface 51 of the light guide plate 5 and laminating the light diffusive sheet on the prism sheet 6 so that the uneven surface (backcoat layer) of the light diffusive sheet is opposed to the surface opposite of the prism surface. The light diffusive sheet of the present invention can prevent occurrence of a rainbow-like annular pattern without deteriorating the front luminance and view angle of the area light source even when combined with a downward-facing prism sheet.

摘要翻译： 本发明的光漫射片包括在一侧设置有光漫射层3的透明聚合物片和具有0.5μm或更小的算术平均偏差和80μm的平均间距或相对侧较窄的不平坦表面4a 。 这种不平坦的表面可以通过在透明聚合物片上形成包含特定平均直径的颗粒与粘合剂树脂的特定比例的混合物的背涂层4来制备。 本发明的区域光源元件7是通过在导光板5上层叠棱镜片6，使得棱镜片6的棱镜面61与导光板5的发光面51相对而形成的 并且将光漫射片层压在棱镜片6上，使得光漫射片的不平坦表面（背涂层）与棱镜表面相对的表面相对。 本发明的光漫射片即使在与向下的棱镜片组合时，也可以防止彩虹状环状图案的发生而不会使面光源的正面亮度和视角变差。