Optical sheet, surface light source device, and transmission display device

An optical member incorporated in a surface light source device including a light source, the optical member comprising:

• a first optical sheet including a light exiting side lens part having unit lenses juxtaposed to one another and each unit lens projecting toward a light exiting side;
• and
• a second optical sheet including a prism part having unit prisms juxtaposed to one another,
• wherein a light scattering layer configured to scatter light is provided to each unit lens,
• wherein the light scattering layer extends along an light exiting side surface of each projected unit lens and constitutes the light exiting side surface of the unit lens,
• wherein a thickness of the light scattering layer around an apex portion of each unit lens is greater than the thickness of the light scattering layer around each end portion of the unit lens, and
• wherein each unit prism includes an apex point, in a section taken along an arrangement direction of the unit prisms.