摘要 |
This light emitting element (24) constitutes a pixel a plurality of which when arranged in rows and columns may form a matrix display board. The element comprises one or more discharge tubes (10, 11, 12). For a board displaying images (textual or video) in color the internal wall of each tube is coated with a fluorescent substance which responds respectively to the red, green and blue portions of the spectrum. By independently varying the intensity of the light emitted by each tube light is obtained at the element output the resultant wavelength of which may extend over the entire visible spectrum. The invention finds use in a display board employed to convey information to crowds of people as for example in a sports stadium.
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