Patent Application
20140151205
The present invention relates to a keycap and particularly to a keycap containing an opaque press surface and a transparent light emitting surface below the press surface to emit light locally.
Illuminated keyboard aims to solve the problem of users of unable to clearly distinguish notations and characters on the keycaps in a dark environment. To improve illumination characteristic of the illuminated keyboard, light transmission architecture and keycap structure are two main issues that have to be seriously focused. Compared with the more complex light transmission architecture, keycap is simpler in structure. The keycap mainly includes a press surface and a plurality of inclined surfaces extended from the press surface. Hence through a simple improvement a great effect can be accomplished.
Many prior techniques concerning improvement of the keycap focused on light emission structure of the press surface. For instance, Taiwan publication No. 200745915 proposes an opaque keycap with a transparent character notation formed thereon to highlight the character notation. U.S. Pat. No. 7,847,204 discloses a keycap with four different transparent colored layers respectively at four corners of the press surface. Taiwan utility model No. M419150 discloses a keycap having a press surface with a transparent portion to allow light to transmit. They all have the disadvantage of occupying too much area on the keyboard by the press surface of the keycap. With the light concentrating on the press surface for emission the entire keyboard is illuminated that makes distinguishing individual keycaps difficult.
There are other types of keycap structures that do not emit light through the press surface, such as Taiwan patent No. I283421. It discloses a backlit key assembly which includes an opaque key and a light guide element surrounding the key. It transfers the lighting element from the traditional press surface to the light guide element such that a ring of bright backlight is presented around the key. But it requires adding an extra light guide element around the key and results in the disadvantages of a higher cost and more complex fabrication and assembly processes.
Another Taiwan patent No. I340402 discloses a keycap capable of emitting light laterally. The keycap has a light incident surface at the bottom and a light emitting surface at one lateral side. The light emitting surface has a refractive surface corresponding to the keycap. When light projects to the light incident surface and is guided by the refractive surface to the light emitting surface, it emits laterally via the light emitting surface and projects to an identification zone corresponding to the keycap. Although it can emit light laterally, the conventional keyboard has the notations and characters located on the keycaps rather than on the identification zone. The transverse light cannot travel longitudinally to illuminate the notations and characters on the keycaps, hence it is not suitable for the conventional illuminated keyboards.
The primary object of the present invention is to overcome the disadvantage of the conventional illuminated keyboards of emitting light through the press surface that causes total illumination and resulting in not distinguishable of the locations of individual keycaps.
To achieve the foregoing object, the present invention provides a locally illuminated keycap located in a keyboard. The keyboard includes a command circuit board that is located beneath the keycap and triggered by a vertical movement of the keycap to issue a keyboard command signal. The keyboard also has a lighting unit to provide light and project the light to the keycap. The keycap includes at least one top edge to form an opaque press surface, at least one bottom edge located below the press surface to form a light incident surface to receive light, and at least one transparent light emitting surface connecting to the top edge and bottom edge to emit light. The light emitting surface is located between the press surface and light incident surface. The press surface and light emitting surface form an inclined angle between them greater than 90 degrees. The press surface, light incident surface and light emitting surface jointly form a light retaining zone. Light from the lighting unit enters the light retaining zone and is masked by the opaque press surface to emit locally through the transparent light emitting surface.
In one embodiment the keyboard further includes a light mask unit located between the lighting unit and keycap.
In another embodiment the light mask unit includes a transparent zone located beneath the light incident surface and formed at an area smaller than that of the light incident surface so that the light from the lighting unit projects to the light incident surface through the transparent zone and enter the light retaining zone.
In yet another embodiment the command circuit board has a reflective portion corresponding to the transparent zone.
In yet another embodiment the light mask unit is a light mask plate.
In yet another embodiment the light mask unit is a light mask layer coated on the command circuit board.
In yet another embodiment the press surface is coated with an opaque layer or made of an opaque material.
In yet another embodiment the light emitting surface is made of a transparent material.
In yet another embodiment the keycap has a transparent character or a transparent notation to allow the light to transmit through the press surface.
In yet another embodiment the keyboard includes a baseboard to hold the keycap.
In yet another embodiment the keyboard includes a driven mechanism to bridge the baseboard and keycap, and an elastic element located in the driven mechanism to allow the keycap to move up and down against the baseboard to trigger the command circuit board.
Through the aforesaid structure, compared with the conventional techniques, the invention can provide at least the following advantages:
1. The location of each keycap is distinguishable clearly. With the press surface of the keycap being opaque and the light emitting surface below the press surface being transparent, after the light projects to the light incident surface, it is masked by the press surface but emits locally through the light emitting surface, hence a light halo is formed around the keycap to facilitate identification thereof. Compared with the conventional illuminated keyboard that emits light on the entire press surface, the locations of individual keycaps of the invention can be clearly identified.
2. Each keycap has a higher luminosity locally. The invention, with the light mask unit located between the lighting unit and keycap and including a transparent zone which is located beneath the light incident surface and formed at an area smaller than that of the light incident surface, a greater portion of the light can directly project through the transparent zone to the light incident surface and enter the light retaining zone, thus only a small portion of the light does not project to the light incident surface but scatters outside.
3. Fabrication process is simpler and the cost is lower. Compared with the conventional keycap with illumination occurred to the surrounding thereof, the invention does not need an extra light guide element to surround the keycap. Hence fabrication process is simplified and the cost can be reduced.
4. The light emitted from the keycap is not masked by user's fingers. Since the keycap of the invention does not emit light from the press surface, during user's keystroke operation illumination of the keycap is not affected by masking of the press surface. Hence the keyboard of the invention provides improved illumination characteristics.
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 one embodiment, the press surface 10 is coated with an opaque layer or made of an opaque material. The transparent light emitting surface 12 is preferably made of a transparent material. It is to be noted that the invention does not limit fabrication processes of the keycap 1. While the invention emphasizes that the press surface 10 is opaque, to make the character or notation on the press surface 10, such as character A, emit light in the dark, the keycap 1 also can include a transparent character or a transparent notation to allow the light to transmit through the press surface 10.
More specifically, the press surface 10 is surrounded by at least one top edge 13 connecting to each other. The light incident surface 11 is surrounded by at least one bottom edge 14 connecting to each other. The light emitting surface 12 is connected to the top edge 13 and bottom edge 14. In another embodiment the top edge 13 and bottom edge 14 include respectively four sets, hence the press surface 10 and light incident surface 11 are respectively quadrilateral. The light incident surface 11 is formed at an area greater than that of the press surface 10, hence the light emitting surface 12 is connected to the press surface 10 via the top edge 13 to form a hollow frustro-conical structure, but this is not the limitation of the invention.
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As a conclusion, the keycap of the invention includes an opaque press surface, a light incident surface below the press surface to receive light, and at least one transparent light emitting surface located between the press surface and light incident surface to emit light. The press surface and light emitting surface form an inclined angle between them greater than 90 degrees. Compared with the conventional keycaps that project light outwards through the press surface, the press surface of the keycap of the invention masks the light projected from the light incident surface but allows the light to emit locally through the light emitting surface, hence a light halo is formed around the press surface, and the individual keycap of the illuminated keyboard is more distinguishable.
In addition, the invention also provides a light mask unit located beneath the light incident surface and formed at a smaller size than that of the light incident surface so that light generated by the lighting unit can project to the light incident surface through the transparent zone and enter the light retaining zone. Thereby only a small portion of the light cannot project to the light incident surface but scatters outside, and the light emitting surface of the keycap has a greater luminosity.
Furthermore, because the keycap of the invention does not emit light through the press surface, when users perform keystroke operation illumination of the keycap is not affected by masking of the press surface. Thus the keyboard of the invention also can improve illumination characteristics. In short, the present invention provides significant improvements over the conventional techniques.
While the preferred embodiments of the invention have been set forth for the purpose of disclosure, they are not the limitations of the invention, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.
