The present invention relates to a keyboard and particularly to a keyboard equipped with light emitting structure.
Among numerous types of keyboards now available on the market, illuminated keyboards integrated with light emitting modules have been provided by some producers to meet different consumers' requirements and make them more appealing to the consumers with this additional feature. The conventional illuminated keyboards mostly adopt a light guide plate for the keyboard light emitting module. References can be found in U.S. Pat. Nos. 6,217,183, 6,467,924, 6,918,677, 7,172,303, 7,193,535, 7,172,303, 7,283,066 and 6,860,612.
However, with the prevailing trend of electronic products that heavily focuses on slim and light, now many producers, in additional to developing the illuminated keyboard, also devote a great deal of research and development on reducing total thickness of the keyboard module.
To improve the drawback of increasing the total keyboard thickness caused by using the light guide plate as the light emitting module, Taiwan publication No. 201320135 and Taiwan patent Nos. 1345719 and 1399776 propose a light emitting module that directly uses a circuit board made of light guide material. However, in order to generate uniform overall illumination an extra light guide structure usually is needed, such as reflective bulged spots. Such additional feature eventually makes reducing keyboard thickness unattainable. Moreover, the illuminated keyboards now commonly adopted in the industry, in addition to the aforesaid light guide structure, also include a plurality of coupling elements and a baseboard to hold the coupling elements to ensure that each key can be depressible and restore effectively. The baseboard and coupling elements are formed at a certain height. Hence, with the constraints of the light guide structure, baseboard and coupling elements, slimness of the illuminated keyboard becomes very difficult.
The primary object of the present invention is to overcome the thickness problem occurring to the conventional illuminated keyboards.
To achieve the foregoing object, the invention provides a keyboard equipped with light emitting structure that comprises a plurality of keycap portions, a plurality of driven mechanisms each corresponding to one keycap portion, a light guide command circuit board and a light emitting unit. The command circuit board includes an upper light guide plate, a lower light guide plate and a middle plate located between the upper and lower light guide plates. The upper light guide plate and lower light guide plate have respectively an upper trigger portion and a lower trigger portion at one side facing the middle plate that can be triggered to generate a command signal. The middle plate has a hollow zone corresponding to the upper and lower trigger portions, a plurality of coupling portions corresponding to the keycap portion to couple with the driven mechanism, and a plurality of apertures corresponding to the coupling portions. The upper light guide plate also has an upper mask layer at one side facing the keycap portion. The upper mask layer has a transparent zone corresponding to the keycap portion. The light emitting unit provides light to the command circuit board. The command circuit board receives the light and transmits the light evenly to illuminate the keycap portion through the transparent zone.
In one embodiment the lower light guide plate has a lower reflective layer at one side opposing the lower trigger portion.
In another embodiment the lower light guide plate has a lower reflective layer at same side of the lower trigger portion.
In yet another embodiment the upper light guide plate has an upper reflective layer below the upper mask layer.
In yet another embodiment the upper light guide plate has an upper reflective layer at same side of the upper trigger portion.
In yet another embodiment the lower light guide plate has a lower mask layer below the lower reflective layer.
In yet another embodiment the middle plate has an upper insulation layer and a lower insulation layer respectively at one side facing the upper trigger portion and lower trigger portion, and the upper insulation layer and lower insulation layer have respectively an upper uncovered zone and a lower uncovered zone corresponding to the hollow zone.
In yet another embodiment the upper light guide plate includes a top portion and a lateral portion connected to the top portion. The top portion and lateral portion form a housing space to hold the lower light guide plate.
In yet another embodiment the upper light guide plate has a plurality of installation apertures corresponding to the coupling portions and run through by the driven mechanisms for latching on the middle plate.
The keyboard of the invention thus formed, compared with the conventional keyboards, provides many advantages, notably:
1. The keyboard can be made thinner. With the driven mechanisms directly mounted onto the command circuit board, the baseboard used in the conventional keyboards can be omitted. Hence total thickness of the keyboard can be reduced.
2. Improved illumination effect. With the upper and lower light guide plates to transmit light, and the upper mask layer on the upper light guide plate to confine light transmission path, light projects merely towards the keycap portions.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
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In addition, the light emitting unit 4 can be held at two sides of the command circuit board 3 or in a housing space (not shown in the drawings) formed on the command circuit board 3. Furthermore, the upper light guide plate 31 has an upper mask layer 312 at one side facing the keycap portion 1. The upper mask layer 312 has a transparent zone 313 corresponding to each keycap portion 1. The upper mask layer 312 can be formed on the upper light guide plate 31 by physical or chemical coating in ink, or can be an opaque plate. Thus, the command circuit board 3 can receive light from the light emitting unit 4 and evenly transmit the light to illuminate the keycap portion 1 through the transparent zone 313. The ink used on the mask layer can be black ink or other ink with equivalent opaque effect.
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As a conclusion, the keyboard equipped with light emitting structure according to the invention includes a plurality of keycap portions, a plurality of driven mechanisms and a light guide command circuit board. The command circuit board includes an upper light guide plate, a lower light guide plate and a middle plate between the upper and lower light guide plates. The upper and lower light guide plates have respectively an upper trigger portion and a lower trigger portion at one side facing the middle plate that can be triggered to generate a command signal. The middle plate has a hollow zone corresponding to the upper and lower trigger portions, a plurality of coupling portions corresponding to the keycap portion to couple with the driven mechanism and a plurality of apertures corresponding to the coupling portions. The upper light guide plate also has an upper mask layer at one side facing the keycap portion that contains a transparent zone. Thereby the command circuit board can receive light from a light emitting unit and transmit the light to illuminate the keycap portion through the transparent zone. As a result, the keyboard can be made thinner.