OPTICAL SHEET FOR LIQUID CRYSTAL DISPLAY DEVICE, BACKLIGHT UNIT FOR LIQUID CRYSTAL DISPLAY DEVICE AND PRODUCTION METHOD OF OPTICAL SHEET FOR LIQUID CRYSTAL DISPLAY DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an optical sheet capable of preventing sticking as well as preventing scratching on another optical member disposed on a back face side of the sheet.SOLUTION: An optical sheet 1 for a liquid crystal display device includes a plurality of protruding portions 13a, 18a scattered on a back face of the sheet, in which the protruding portions 13a, 18a each have a flattened semi-spherical shape or a flattened conical shape with a rounded apex. Preferably, the protruding portions 13a, 18a are half-split spheroids. An occupancy area ratio of the plurality of protruding portions 13a, 18a is preferably 2% or more and 80% or less. An average diameter of the protruding portions 13a, 18a is preferably 5 μm or more and 60 μm or less, and an average height is preferably 0.5 μm or more. A diffraction grating pattern with multiple rows oriented in one direction is preferably disposed on the back face in a region where the plurality of protruding portions 13a, 18a are absent. The diffraction grating pattern is preferably a pattern resembling scratch marks or hairlines in the one direction. The optical sheet preferably has a diffraction grating pattern also on a back face side of the plurality of protruding portions 13a, 18b, continuing to the above diffraction grating pattern.SELECTED DRAWING: Figure 1