TWI407473B - Keypad module - Google Patents

Abstract

The invention discloses a keypad module which includes a light guide plate, a keymat and a light source. The keymat is assembled in a side of light guide plate, and the light source is mounted on the light guide plate. The light guide includes at least one focusing light area, the focusing light area forms a coarse surface. The keymat forms a plurality of bars corresponding to the focussing light area. The light can be reflected and refracted by the coarse surface and be reflected by the bars so as to be focused in the focusing light area.

Description

Keyboard module

The present invention relates to a keyboard module, and more particularly to a keyboard module applied to a portable electronic device.

In the design of a portable electronic device such as a mobile phone, a plurality of light-emitting diodes (LEDs) are often used as a light source and disposed on one side of a light guide plate. When the light emitted by the LED illuminates the surface of the light guide plate, it can be refracted or reflected on the surface of the light guide plate to be directed to the keyboard to be illuminated. However, due to the limitation of the structure of the light guide plate, the brightness of the keyboard away from the LED light source is still insufficient, and more LED light sources are needed to meet certain brightness requirements and increase the design cost.

In view of the above, it is necessary to provide a keyboard module that can enhance the brightness of a button away from a light source and reduce the amount of light used.

A keyboard module includes a light guide plate, a keyboard and a light source, the keyboard is disposed on one side of the light guide plate, the light source is disposed at one end of the light guide plate, and the light guide plate includes at least one light collecting area, The concentrating area is provided with a roughening surface, and the keyboard is provided with a plurality of ridges corresponding to the concentrating area, and the light emitted by the light source is concentrated in the concentrating area through the reflection and refraction of the roughened surface and the reflection of the ridge.

Compared with the prior art, the keyboard module is provided with a roughening surface in the concentrating area of the light guide plate, and a ridge is disposed in a corresponding area of the keyboard to collectively converge the light in the concentrating area, thereby improving the The brightness of the area. The keyboard module of the invention uses only one LED light source, which saves the cost while enhancing the brightness of the keyboard.

The keyboard module of the preferred embodiment of the present invention is applied to a portable electronic device such as a mobile phone or a personal digital assistant (PDA). Referring to FIG. 1 , the keyboard module 100 includes a light guide plate 10 , a keyboard 30 , and an LED light source (not shown). The keyboard 30 is disposed on one side of the light guide plate 10 , and the LED light source is disposed at one end of the light guide plate 10 . .

Referring to FIG. 2 and FIG. 3, the light guide plate 10 can be made of polycarbonate (Polycarbonate, PC) or polymethyl-Methacrylate (PMMA). The light guide plate 10 includes a top end 12 and a bottom end 14 disposed opposite each other. An assembly hole 120, a plurality of numeric keyholes 122, a plurality of navigation keyholes 124, and a plurality of openings 126 are defined in the light guide plate 10.

The mounting hole 120 is disposed adjacent to the top end 12 for mounting an LED light source. The position of the digital keyhole 122 corresponds to the digital key to be illuminated, and when the light from the LED light source propagates to the digital keyhole 122, the corresponding digital key can be illuminated. The light guide plate 10 is provided with a protrusion 128 between the navigation key holes 124. The protrusion 128 includes four sides (not labeled), wherein the protrusion 128 is relatively blasted and adhered to the outer periphery of the surface of the three sides of the mounting hole 120 and the outer circumference thereof and the two-digit keyhole 122 near the bottom end 14 The roughening process forms a roughened surface 1282. The small particles are made of a material having a higher absorbance or a lower light transmittance, so that the light of the LED light source propagates to the roughened surface 1282 and accumulates in the region by mutual refraction and reflection, thereby improving the navigation keyhole 124. And the brightness of the area where the numeric keypad 122 is located at the bottom end 14.

The opening 126 can be triangular, quadrangular or other polygonal. The sidewalls of each opening 126 can not only refract some of the light rays to the adjacent digital keyholes 122 and navigation keyholes 124 to illuminate the corresponding keys, but also reflect other light rays for propagation to other openings 126. . The sidewall of the opening 126 that is closer to the mounting aperture 120 is designed to have a larger angle of incidence, i.e., greater than the total reflection critical angle of incident light from the LED source to enable incident light to propagate through total reflection to the next opening 126. . Since the light travels through a plurality of total reflections, the travel angle will become narrower. At this time, the incident angle design of the side wall of the opening 126 away from the mounting hole 120 is correspondingly smaller, so that the incident light energy can be uniformly transmitted to the bottom end 14 . Opening 126.

Referring to FIGS. 2 to 4 , the keyboard 30 includes a housing 32 , a plurality of numeric keys 34 , a navigation key 36 , and a plurality of contacts 38 . The housing 32 includes an opposite outer surface 322 and an inner surface 324. The numeric keys 34 and navigation keys 36 project from the outer surface 322. The contacts 38 extend from the inner surface 324 for passing through the light guide plate. The digital keyhole 122 and the navigation keyhole 124 of the 10 are in contact with a circuit board (not shown) in the portable electronic device. The inner surface 324 of the housing 32 is located at a region of the navigation key 36 and a region away from the two numeric keys 34 of the navigation key 36. The plurality of ribs 326 are protruded from the inner surface 324 of the housing 32. The rib 326 is integrally injected with the housing 32 through a transparent material such as silicone. forming. Each of the ribs 326 is an arc segment centered on the LED light source, that is, the distance between the light emitted by the LED light source and each of the ribs 326 is equal. The ribs 326 are curved to maximize the light emitted by the LED light source, and the light is concentrated by the reflection in the navigation key 36 and the area of the two numeric keys 34 away from the navigation key 36, thereby further enhancing the brightness of the area. .

When the light from the LED light source enters the nearest opening 126, the sidewall of the opening 126 is totally reflected to the next opening 126, thereby sequentially transmitting light to the opening 126 near the bottom end 14 to illuminate the light guide plate 10. At the same time, the light emitted by the LED light source is refracted and reflected by the roughened surface 1282 in the area of the navigation key 36 and the digital key 34 away from the LED light source, and the reflection of the ridge 326 causes the light to converge as much as possible in the area to enhance navigation. The brightness of the key 36 and the number key 34 away from the LED light source.

It will be appreciated that the roughened surface 1282 of the present invention is not limited to being formed by protruding small particles, but may also be formed by providing depressions on the projections 128.

It will be appreciated that the present invention is not limited to increasing the brightness of the numeric keypad 122 and the area of the navigation keyhole 124 remote from the LED source, but can be used for any other concentrating area that requires high brightness display.

The present invention provides a roughening surface in the condensing area of the light guide plate 10, and a rib is disposed at a position corresponding to the condensing area of the keyboard 30, thereby effectively concentrating light in the concentrating area, thereby enhancing the concentrating area. brightness. The keyboard module 100 of the present invention uses only one LED light source, and is easy to design and low in cost.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and equivalent modifications or variations made by those skilled in the art in light of the spirit of the present invention are It should be covered by the following patent application.

100‧‧‧ keyboard module

10‧‧‧Light guide plate

12‧‧‧Top

120‧‧‧Assembly holes

122‧‧‧Digital keyhole

124‧‧‧Navigation keyhole

126‧‧‧ openings

128‧‧‧ bumps

1282‧‧‧ roughened surface

14‧‧‧ bottom

30‧‧‧ keyboard

32‧‧‧ housing

322‧‧‧ outer surface

324‧‧‧ inner surface

326‧‧ ‧ ribs

34‧‧‧number keys

36‧‧‧ navigation keys

38‧‧‧Contacts

1 is a perspective view of a keyboard module in accordance with a preferred embodiment of the present invention;

2 is an exploded perspective view of the keyboard module shown in FIG. 1;

3 is an exploded perspective view of the keyboard module shown in FIG. 1 in another direction;

4 is a plan view of the keyboard of the keyboard module shown in FIG. 1.

30‧‧‧ keyboard

32‧‧‧ housing

326‧‧ ‧ ribs

Claims (10)

A keyboard module includes a light guide plate, a keyboard and a light source. The keyboard is disposed on one side of the light guide plate, and the light source is disposed at one end of the light guide plate. The improvement is that the light guide plate includes at least one light collecting layer. a region, the concentrating region is provided with a roughening surface, and the keyboard is provided with a plurality of ridges corresponding to the concentrating region, and the light emitted by the light source is concentrated and reflected by the roughening surface and the reflection of the ridges Concentration area. The keyboard module of claim 1, wherein each of the ribs is an arc segment centered on the light source. The keyboard module of claim 1, wherein the roughened surface is formed by sandblasting or adhering small particles on the light guide plate. The keyboard module of claim 3, wherein the small particles are made of a material having a high absorbance or a low light transmittance. The keyboard module of claim 1, wherein the light guide plate is provided with a plurality of openings, an incident angle of a sidewall of the opening close to the light source is greater than a total reflection critical angle of the incident light, and an entrance of the sidewall away from the opening of the light source. The angle of incidence is less than the angle of incidence of the sidewall of the opening near the light source. The keyboard module of claim 1, wherein the light guide plate is provided with a protrusion, and the roughened surface is formed on the convex surface and the outer circumference. The keyboard module of claim 1, wherein the keyboard comprises a casing, and the rib is integrally injection molded with the casing and disposed on a surface of the casing. The keyboard module of claim 1, wherein the rib is made of a transparent material. The keyboard module of claim 1, wherein the light guide plate is made of polycarbonate or polymethyl methacrylate. The keyboard module of claim 1, wherein the light guide plate defines a mounting hole, and the light source is installed in the mounting hole.