| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical sheet having excellent restoring property and scratch resistance even when the sheet has a convex optical unit, and requiring no protective sheet in a production process and during transportation, and to provide a surface light source device and an image display device having the optical sheet.SOLUTION: The optical sheet includes an optical function developing part comprising a plurality of convex optical units having ridgelines arrayed on one surface side of a transparent substrate. The optical function developing part is made of a cured product of an active energy ray-curable resin composition containing an acrylic resin and/or a methacrylic resin. A dent depth in an apex of each optical unit measured by a specified denting load is a specified value or more. When an acute angle formed by the ridgeline of the optical unit and an edge of the optical sheet is defined as a bias angle, an angle &thetas; of the smallest angle in the bias angles on the respective edges satisfies 2°≤&thetas;≤45°. |
