| 摘要 |
PROBLEM TO BE SOLVED: To provide a daylighting sheet capable of suppressing direct projection of sunlight (direct solar beam), effectively taking in light and making an outdoor side visible from an indoor side.SOLUTION: A daylighting sheet 20 is configured to be installed in an opening of a building with a sheet surface thereof vertically disposed. The daylighting sheet 20 includes: a base material layer 22 having light transmissivity; and a light scattering layer 23 arranged on one side of the base material layer and configured to scatter light. The light scattering layer includes: light transmission parts 24 aligned in plurality along the one side of the base material layer, having a refractive index of Nand configured to transmit light; and light scattering parts 25 arranged between the plurality of light transmission parts and configured to scatter light. Under a position that the daylighting sheet is installed in the opening of the building, with regard to opposing two sides in a vertical section in a thickness direction of neighboring two light scattering parts, a predetermined relation is satisfied if an angle formed with a horizontal plane by a prospective line connecting an indoor side end part of the side of the lower light scattering part and an outdoor side end part of the side of the neighboring upper light scattering part is regarded as a prospective angle &thetas;, an elevation angle when the meridian transit height of the sun is highest in a year is regarded as &thetas;, and a refractive index of the air is regarded as N. |
