Patent Application
20090263093
1. Field of the Invention
The present invention relates to light guiding mechanisms and, particularly to a light guiding mechanism used in portable electronic devices.
2. Description of Related Art
Portable electronic devices usually include keypads for inputting information. When operating such portable electronic devices in a dark room, keys of the keypads need to be illuminated for the user to operate. Each key can be illuminated by a respective light source corresponding to the key. However, this type of keypad is expensive since many light sources are required.
A typical way to reduce the number of light sources is to use a light guiding member in the form of a transparent plate. A typical light guiding member includes an array of apertures. As each key is arranged to align with the corresponding aperture, and the keys are illuminated by the light guided by the light guiding member. However, bright areas of the light guiding member may appear where the light sources are disposed adjacent to the light guiding member. Thus, there is decreased illumination uniformity of the light guide plate, which increases the difficulty of producing a desirable uniform illumination for the keypad.
Therefore, there is room for improvement within the art.
Many aspects of a light guiding mechanism can be better understood with reference to the following drawings. These drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present light guiding mechanism. Moreover, in the drawings like reference numerals designate corresponding parts throughout the several views. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment.
Embodiments will now be described in detail below and with reference to the drawings. The light guiding mechanism can be applied to an electronic device, for example, a mobile phone. Therefore, the light guiding mechanism is shown in the abstract, rather than associated with any particular electronic device.
The light guiding mechanism 20 includes a light guiding plate 22 and a shielding plate 24. The light guiding plate 22 defines a plurality of first holes 222 and a plurality of second holes 224. The first holes 222 correspond to and accommodate the light sources 14 therein. The second holes 224 correspond to and accommodate the keys of the keypad assembly (neither shown). The light guiding plate 22 can be made of one or more materials selected from a group consisting of polyvinyl chloride (PVC), polycarbonate, polystyrene, and any other thermoplastic resins.
The shielding plate 24 includes a rectangular frame 242 defining a central hole 244. The chamber 244 has substantially the same shape as the light guiding plate 22, and has a size just slightly larger than the light guiding plate 22. The chamber 244 is configured (e.g., structured/arranged) for receiving the light guiding plate 22 therein, and the frame 242 surrounds a peripheral wall 226 of the light guiding plate 22. The shielding plate 24 can be made of an opaque material with a black color, e.g., the mixture of resin and carbon.
The frame 242 and the peripheral wall 226 can be integrally attached together by various means, such as adhesives or hot melt.
Because the frame 242 surrounds the peripheral wall 226 of the light guiding plate 22, unexpected light leaks, such as light emitted from the light sources 14 leaking through the peripheral wall 226, can be reduced. Thus, the brightness of the light guided by the light guiding plate 22 and the light guiding effect of the light guiding plate 22 are improved.
It is to be understood, however, that even through numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200810301155.3 | Apr 2008 | CN | national |
This application is related to co-pending U.S. patent applications (Attorney Docket No. US20127), entitled “LIGHT GUIDING MECHANISM”, by Jin-Ti Cao et al. The application has the same assignee as the present application and has been concurrently filed herewith. The above-identified applications are incorporated herein by reference.
