US Patent 7070314 Light channelling window panel for shading and illuminating rooms

A method for producing a light channelling panel by making an array of angled cuts in a first transparent plastic sheet, making a similarly spaced array of angled cuts in a second plastic sheet, transposing or flipping the second sheet and fixing it in contact with the first sheet to form a panel with an array of internal light channels. Alternatively, by making an array of angled cuts in the surface of a transparent plastic sheet and an array of similarly spaced angled cuts in the opposite surface of the transparent plastic sheet to form a panel with an array of internal light channels. Said light channelling panel when positioned in a window of a building channels substantially all sunlight incident on the panel through the panel and over the ceiling in the building thereby illuminating the building with daylight and shading work areas near the window.