The invention of the bright-white light-emitting diode (LED) in the 1990s marked the beginning of a revolution in lighting. Cheap, long-lasting, and needing little power, bright LEDs are increasingly the light source of choice for flashlights, traffic signs, even the brilliant marquees in places like New York City’s Times Square. They are also used to illuminate the picture in some large-screen TVs. But LEDs still have not made much headway in our homes and offices, where the general lighting provided by incandescents and fluorescents is still superior.
PhlatLight's large light emitting surface lies under the window embedded in its packaging. | Image courtesy of Luminus
Part of the reason is that individual LEDs are typically quite small; the surface area of the semiconductor material that emits light is only about one square millimeter. As a consequence, a bright LED, of the kind found in a flashlight, might produce 80 lumens ...
