Light guide structure and keypad having the same

• US 7,455,416 B2
• Filed: 11/17/2006
• Issued: 11/25/2008
• Est. Priority Date: 11/17/2006
• Status: Expired due to Fees

• Current Assignee: Ichia Technologies Incorporated
• Original Assignee: Ichia Technologies Incorporated
• Inventors: Chen, Ko-Ju
• Primary Examiner(s): Sawhney; Hargobind S
• Application Number:
  US11/560,957
• Publication Number:
  US 20080117618A1
• Time in Patent Office: 739 Days
• Field of Search: 362/85, 362/24, 362/29, 362/30, 362/86, 362/227, 362/236, 362/240, 362/244, 362/326, 362/327, 362/330, 362/337, 362/612, 362/616, 362/620, 200/5.A, 200/512, 200/513, 200/310, 200/313, 200/314
• US Class Current: 362/85
• CPC Class Codes: H01H 13/83 characterised by legends, e.g. Braille, liquid crystal displays, light emitting or optical elements
• CPC Class Codes: H01H 2219/03 in transparent keyboard
• CPC Class Codes: H01H 2219/058 Optical grid, collimator or microlouver
• CPC Class Codes: H01H 2219/062 Light conductor
• CPC Class Codes: H01H 2221/07 transparent
• CPC Class Codes: H04M 1/22 Illumination; Arrangements for improving the visibility of characters on dials

Abstract

A light guide structure installed in a keypad includes a light guide plate and a plurality of light emitting components. The light guide plate has a plurality of light guiding areas, each having a center light guiding circle with a plurality of light guide rings extended outward. The light guiding area and the adjacent light guiding area form light guide rings connected with an intersection, and the center light guiding circle and the light guide rings have a plurality of arc light guiding particles. The light emitting component is installed under the light guide plate and at the corresponding center position of the center light guiding circle. If the light emitting component is lit, light is projected onto the light guide plate and refracted by the light guiding particles to produce a light transmission effect for showing a number or a figure on the surface of the push button.

Claims

1. A light guide structure, installed inside a keypad, comprising:

a light guide plate, having a plurality of light guiding areas, and each light guiding areas has a center light guiding circle, and the external periphery of the center light guiding circle has at least one light guide ring, and each light guiding area and its adjacent light guiding area form at least one light guide ring connected with an intersection, and the center light guiding circle and the light guide ring have a plurality of light guiding particles; and

a plurality of light emitting components, installed at a center position corresponding to the center light guiding circle,

wherein the light guiding particles are in an arc shape, and the diameter of the light guiding particles falls within a range of 0.01 mm˜

0.1 mm.

2. The light guide structure of claim 1, wherein the distribution density of the light guiding particles of the center light guiding circle is scatterly distributed, and the distribution density is equal to 1 dot/mm².

3. The light guide structure of claim 1, wherein the distribution densities of the light guiding particles are evenly and then densely distributed in sequence, and the evenly distributed density is 10 dots/mm², and the densely distributed density is 20 dots/mm².

4. The light guide structure of claim 1, wherein the light emitting component is a light emitting diode.

5. The light guide structure of claim 1, wherein the light emitting component is packaged in a thin film circuit board that is comprised of two soft plastic thin films, and an electric circuit is printed on one of the plastic thin films, and the light emitting component is electrically connected with the electric circuit.

6. A keypad having a light guide structure, comprising:

a thin film circuit board, having an electric circuit and a light emitting component disposed thereon, and the light emitting component is electrically connected with the electric circuit;

a first elastic layer, disposed on the thin film circuit board, and having a plurality of metal plates;

a light guide plate, disposed on the first elastic layer, and having a plurality of light guiding areas, and the light guiding area has a center light guiding circle, and the external periphery of the center light guiding circle has at least one light guide ring, and each light guiding area and its adjacent light guiding area form at least one light guide ring connected with an intersection; and

the center light guiding circle and the light guide ring have a plurality of light guiding particles;

a second elastic layer, disposed on the light guide plate, and comprised of a rubber body and a hard plastic thin film disposed on the surface of the rubber body, and the bottom of the rubber body has a protruding body corresponding to the metal plate; and

a push button module, installed on the second elastic layer, and comprising a plurality of push buttons, and each push button corresponds to each protruding body.

7. The keypad having a light guide structure of claim 6, wherein the thin film circuit board is comprised of two soft plastic thin films.

8. The keypad having a light guide structure of claim 6, wherein the light emitting component is a light emitting diode.

9. The keypad having a light guide structure of claim 6, wherein the first elastic layer is made of a transparent plastic material.

10. The keypad having a light guide structure of claim 6, wherein the light guiding particles are in an arc shape, and the diameter of the light guiding particles falls within a range of 0.01 mm˜

0.1 mm.

11. The keypad having a light guide structure of claim 6, wherein the distribution density of the light guiding particles of the center light guiding circle is scatterly distributed, and the distribution density is equal to 1 dot/mm².

12. The keypad having a light guide structure of claim 6, wherein the distribution densities of the light guiding particles of the light guide ring are evenly distributed and then densely distributed in sequence, and the evenly distributed density is equal to 10 dots/mm², and the densely distributed is equal to 20 dots/mm².

13. The keypad having a light guide structure of claim 6, further comprising an adhesive layer disposed between first and second elastic layers and the push button module.

14. A keypad having a light guide structure, comprising:

a thin film circuit board, having an electric circuit and a light emitting component disposed thereon, and the light emitting component is electrically connected with the electric circuit;

a first elastic layer, disposed on the thin film circuit board, and having a plurality of apertures, and a metal plate is installed on another side of the apertures;

a light guide plate, disposed on the first elastic layer, and having a plurality of light guiding areas, and the light guiding area has a center light guiding circle, and the external periphery of the center light guiding circle has at least one light guide ring, and each light guiding area and its adjacent light guiding area form at least one light guide ring connected with an intersection, and the center light guiding circle and the light guide ring have a plurality of light guiding particles, and the light guide plate has a plurality of through holes;

a push button module, disposed on the light guide plate, and comprised of a plurality of push buttons, and each push button installs a second elastic layer therein, and the bottom of the second elastic layer has a protruding body, and the protruding body passes through the through hole of the light guide plate.

15. The keypad having a light guide structure of claim 14, wherein the thin film circuit board is comprised of two soft plastic thin films.

16. The keypad having a light guide structure of claim 14, wherein the light emitting component is a light emitting diode.

17. The keypad having a light guide structure of claim 14, wherein the first elastic layer is made of a transparent plastic material.

18. The keypad having a light guide structure of claim 14, wherein the light guiding particles are in an arc shape, and the diameter of the light guiding particles falls within a range of 0.01 mm˜

0.1 mm.

19. The keypad having a light guide structure of claim 14, wherein the distribution density of the light guiding particles of the center light guiding circle is scatterly distributed, and the distribution density is equal to 1 dot/mm².

20. The keypad having a light guide structure of claim 14, wherein the distribution densities of the light guiding particles of the light guide ring are evenly distributed and then densely distributed in sequence, and the evenly distributed density is equal to 10 dots/mm², and the densely distributed density is equal to 20 dots/mm².

21. The keypad having a light guide structure of claim 14, wherein the second elastic layer is made of a transparent rubber material.

22. A light guide structure, installed inside a keypad, comprising:

a light guide plate, having a plurality of light guiding blocks corresponding to the push buttons of the keypad, and the light guiding block has a plurality of light guiding particles; and

a plurality of light emitting components, disposed under the light guide plate and perpendicular to the light guide plate,

wherein the distribution density of the light guiding particles is more scatterly distributed if the distance from a light source is closer, and the distribution density of the light guiding particles is more densely distributed if the distance from the light source is farther, and the light guiding particles are in an arc shape, and the diameter of the light guiding particles falls within a range of 0.01 mm˜

0.1 mm and the distribution density falls within a range from 1 dot/mm² to 20 dots/mm².