| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical sheet which can intercept electromagnetic waves and to provide a back light unit which can reduce the thickness, the weight and the loss of rays of a liquid crystal display device. SOLUTION: The optical sheet 1 has a transparent base layer 2 and an optical layer 3 layered on the surface of the base layer 2 and further has a conductive printed later 4 having a mesh pattern. The conductive printed layer 4 preferably contains carbon black, silver powder or gold powder. The line width L of the mesh pattern is preferably >=10 μm and <=100 μm. The pitch P of the mesh pattern is preferably >=50 μm and <=5 mm. The possession rate of the print in the conductive printed layer 4 is preferably >=5% and <=50%. |
