US Patent 7285903 Display with bright backlight

Methods and apparatus are provided for projecting light carrying a data image. The apparatus comprises a first layer having regions of electrically alterable variable light transmittance adapted to form the data image, and a hollow cavity backlight having a light exiting surface coupled to the first layer and adapted to provide light to the first layer through the light exiting surface from one or more light emitters some of which point in a principal direction other than at right angles to the light exiting surface. In a preferred embodiment, LEDs are used as the light emitters and are preferably mounted on one or more printed circuit boards or other support tilted at non-zero angles with respect to the light exiting surface.