1. Technical Field
The present disclosure relates to a light guide apparatus, especially to a light guide apparatus with uniform illumination and a electronic device employing the light guide apparatus.
2. Description of Related Art
To facilitate the use of electronic devices in the dark or in low light conditions, some electronic devices such as mobile phones are provided with LED backlit icons. Because the LED light sources have a directional characteristic, when needing to illuminate many icons, a light guide is usually used to guide the light beams from the LED light sources such that the icons can be evenly illuminated.
Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
The disclosure, including the accompanying drawings, is illustrated by way of example and not by way of limitation. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
Referring to
Referring to
The light intermediate portion 205 includes a first surface 201 and a second surface 202 opposite to the first surface 201. The light beams enter the light guide member 20 from the opposite ends of the light guide member 20 and refract out of the light guide member 20 through the first surface 201. The light beams refracting out of the light guide member 20 pass through the transparent pattern of each button 12, thus allowing a user to recognize the icons 12 according to their respective glowing pattern in the dark or in low light conditions. The first surface 201 includes an intermediate exposed portion 2011 and two outer portions 2012 located on opposite sides of the exposed portion 2011, the second surface 202 includes an intermediate portion 2021 and two outer portions 2022 located on opposite sides of the intermediate portion 2021.
The shielding member 24 is located behind the light guide member 20 and covers the second surface 202 and the other lateral surfaces of the light guide member 20. The shielding member 24 in the embodiment is made of rubber.
If there is no scatter layer 21 and reflective layer 23, because the two LEDs 22 are respectively arranged at the two ends of the light guide member 20, the regions near the two ends of light guide member 20 are brighter than the middle region of the light guide member 20.
In the embodiment, the light beams reaching the scatter layer 21 are scattered. That is, some of the light beams travel out from the scatter layer 21, and some of the light beams are reflected and continue to travel in the light guide member 20. As a result, the light beams refracting out from the regions of first surface 201 adjacent to the LED 22 is reduced as compared to when there is no scatter layer 21 arranged on the first surface 201. The reflective layer 23 reflects the light beams reaching the second surface 202 to the middle region of the first surface 201, such that more light beams refract out from the middle region of the first surface 201 as compared to when there is no reflective layer 23 arranged on the second surface 202. The light guide member 20 can then give out substantially homogeneous light beams. The brightness of the icons 12 is substantially the same.
In another embodiment, the light guide apparatus 200 may only include one LED 22 arranged at one end of the light guide member 20. The scatter layer 21 may be a diffuser membrane covering the half of the first surface 201 adjacent to the LED 22, and the reflective layer 23 may be a reflective membrane covering the half of the second surface 202 away from the LED 22. In other embodiments, the LED 22 can be located at any position beside the light guide member 20, the position and the area of the scatter layer 21 and the reflective layer 23 can be arranged accordingly.
It is to be understood, however, that even though numerous characteristics and advantages of the present disclosure have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the present disclosure is illustrative only, and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the present disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Number | Date | Country | Kind |
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201110351697.3 | Nov 2011 | CN | national |