Man's new light

Lynn Poole displays the incandescent point source of light from 1909, the 1938 fluorescent line source of light, and the new electro-luminescence flat panel of light. Carl Jensen, a lighting engineer and marketing manager, and Dr. John McNall, the director of research at Westinghouse Electric Corp., discuss how this light is generated by exciting phosphors in alternating electric fields and demonstrate the concept using a tilting board with traps and marbles. Electro-luminescence was first discovered in 1936 by Georges Destriau, shown in a film clip. The guests also make the analogy of keys on a piano to the full electromagnetic spectrum, from radio waves to gamma waves. They explain that lumens are units of light and watts are units of power, and they compare the brightness of electro-luminescence to incandescent and fluorescent bulbs. The new product can become brighter by increasing the voltage or frequency or both, but it has limits. Dr. McNall shows the electrical conductors and other layers making up this artificial source of light and notes that it can be made into many shapes or designs and installed in ceilings, walls, stairs, furniture, and even drapery. However, square panels are the most common shape, as shown in the top of a coffee table and on the walls of a model room. Scientific use of electro-luminescence includes astronautical instrumentation, and electro-enhancement will lead to less x-ray exposure by intensification of fluoroscopy screens. Mr. Jensen predicts that in the future this product could be used for a thin, flat, wall-mounted television screen with controls available remotely for the viewer's convenience.