A keypad device includes a keypad with a plurality of keys in a defined order, and a light guide plate disposed under the keypad. The light guide plate includes a plurality of patterns formed by a method of printing on a surface thereof, and each pattern includes adhesive material and reflective material. The keypad device further includes at least one LED lamp disposed beside the light guide plate.
1. A keypad device comprising:
a keypad with a plurality of keys in a defined order;
a light guide plate disposed under the keypad, the light guide plate comprising a plurality of patterns formed by a method of printing on a surface thereof, and each pattern comprising adhesive material and reflective material; and
at least one LED lamp disposed beside the light guide plate.
2. The keypad device of claim 1 wherein the light guide plate comprises a board or a film.
3. The keypad device of claim 2 wherein the board is made of polymethylmethacrylate (PMMA) material.
4. The keypad device of claim 2 wherein the film is made of polycarbonate (PC) material or polyethylene terephthalate (PET) material.
5. The keypad device of claim 1 wherein the adhesive material is glue.
6. The keypad device of claim 1 wherein the reflective material is made of SiO 2 or TiO 2 .
7. The keypad device of claim 1 wherein the plurality of patterns are located corresponding to the defined order of the plurality of keys.
8. The keypad device of claim 1 further comprising a plurality of metal domes disposed on a side of the light guide plate opposite to the keypad and located in positions corresponding to the plurality of keys.
9. The keypad device of claim 8 further comprising a protective layer disposed between the light guide and the plurality of metal domes for preventing the plurality of metal domes from damaging the light guide plate.
10. The keypad device of claim 9 further comprising a printed circuit board wherein the keypad, the light guide plate, the protective layer, the plurality of metal domes, and the printed circuit board are packed as a whole from top to bottom.
11. The keypad device of claim 8 further comprising a printed circuit board wherein the keypad, the light guide plate, the plurality of metal domes, and the printed circuit board are packed as a whole from top to bottom.