ELF-A New Electroluminescent Display

The ELF screen is a new, flat electroluminescent display which combines very desirable brightness and halftone characteristics with flexible storage capabilities and high scanning speeds. There is no theoretical limitation on the area of the screen. Ferroelectric ceramics are associated with the electroluminescent layer to proved built-in storage and control. The output image is formed in accordance with a charge pattern deposited on the ferroelectric control array. This pattern is established by a signal distribution system, part of which may be incorporated in the screen struc ture. Highlight luminances in excess of 25-foot lamberts have been obtained with contrast ratios of over 50/1 in multielement models. Images may be stored for several minutes or, alternatively, the images can be modified many times per second. Model screens have been built with resolutions of from 4 to 10 elements per inch. Higher resolutions may be obtained by new techniques. A scanning system has been constructed which can distribute the picture information at microsecond switching rates.