| 摘要 |
A remote keyboard has keys which are illuminated for identification under a dim motherboard. For a first embodiment of the invention, the identifying symbol or symbols on each key cap of the keyboard is formed from luminescent material. Alternatively, the symbol or symbols on each key cap are formed from a translucent material in which tritium is embedded. Tritium, which has a half-life of about 12.5 years, emits low-energy beta particle radiation. The radiation, which is of sufficiently low energy that it may be blocked by a piece of paper, may be rendered innocuous by placing clear plastic radiation shields over each key cap. For a second embodiment of the invention, the key caps themselves are molded from luminescent material, while the symbols are formed from contrasting black or dark-colored non-luminescent material. A third embodiment of the invention utilizes fiber optics to convey light from at least one low-power source, such as a light-emitting diode, to each of the various key caps, each of which is molded from a translucent material. The symbols on the key caps are of a color which contrasts with that of the key caps. Black letters on light colored translucent key caps are the preferred combination. Another embodiment of the present invention for backlighting a keyboard is to use a transparent projector pane positioned beneath translucent or transparent key caps on which identifying symbols are printed. Light from a light source at the edge of the projector pane is transmitted throughout the pane. An aperture beneath each key top projects light up through the key caps, illuminating the symbols.
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