Method and apparatus for illuminating a keypad
OwnerRick D. Prindleinventor
Life of this patent
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Abstract
Apparatus for back-lit illumination of key designation characters in a keypad has a plurality of individual translucent key cores arranged in a planar pattern, with a base membrane disposed between key cores and fitting around each key at least the outer ends of the key cores except for the key designation characters. An elastomeric, electroluminescent lamp (EEL) is held in assembly against the inner ends of the key cores so as to illuminate the designation characters when activated and deform locally when a key is depressed.
Claims13
Apparatus for back-lit illumination of key designation characters in a keypad, comprising:
- a plurality of translucent key cores having outer, operating ends and inner, actuating ends, the inner ends being arranged in a specific planar pattern;
- a base membrane disposed around and between the key cores, so as to maintain the specific planar pattern;
- an opaque film covering at least the outer end surface of the key cores except for the key designation characters;
- an elastomeric, electroluminescent lamp held proximate the lower, actuating ends;
- and
- a power supply for activating the electroluminescent lamp upon demand, so as to illuminate the key designation characters.
A method for back lighting the key designation characters in a keypad, comprising the steps of:
- providing a plurality of translucent key cores, wherein each core has an outer, operating end and a inner, actuating end;
- arranging the key cores with the inner ends in a specific, planar pattern;
- maintaining the pattern with a base membrane around and between the inner ends;
- covering at least the outer ends, except for the key designation characters, with an opaque film;
- holding an elastomeric, electroluminescent lamp against the inner ends;
- activating the electroluminescent lamp, so as to illuminate the key designation characters;
- and
- stretching the electroluminescent lamp locally, as the inner ends are displaced from the planar pattern.
A method for back lighting the key designation characters in a keypad, comprising the steps of:
- providing a plurality of translucent key cores, wherein each core has an outer, operating end and a inner, actuating end;
- arranging the key cores with the inner ends in a specific, planar pattern;
- providing an elastomeric, membrane-like, electroluminescent lamp and adhesively attaching the inner ends thereto so as to maintain the pattern;
- covering the surface of at least the outer ends, except for the key designation characters, with an opaque film;
- activating the electroluminescent lamp, so as to illuminate the key designation characters;
- and
- stretching the electroluminescent lamp locally, as the inner ends are displaced from the planar pattern.
Dependencies are inferred from the claim text.