Patent Publication Number: US-2009219733-A1

Title: Electronic device having light guide

Description:
BACKGROUND 
     1. Technical Field 
     The disclosure relates to an electronic device and, particularly, to an electronic device which has a light guide for providing uniform illumination. 
     2. General Background 
     Electronic devices usually adopt light sources for generating light. For example,  FIG. 4  shows an electronic device. The electronic device is a keypad. The keypad includes a transparent main body  1 , an optically clear coating layer  2  painted on the main body  1 , a light tight coating layer  3  painted on the optically clear layer  2 , and a light source beneath the main body  1 . The light tight coating layer  3  defines areas in the shape of characters or icons without light tight coating. The light source backlights the characters or icons so that the keypad can be used even in low ambient light conditions. 
     However, the light source has a directional characteristic. That is, light emitted by the light source is transmitted directionally. If the light source needs to illuminate a large area, light may not evenly illuminate the entire area. 
     Thus, what is needed is an electronic device exhibiting even light effect. 
    
    
     
       BRIEF DESCRIPTION OF THE 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. 
         FIG. 1  is an schematic, front view of an electronic device according to an exemplary embodiment. 
         FIG. 2  is an enlarged, partial section view taken along A-A direction of  FIG. 1 , showing a panel, a base plate, a light guide, and light sources. 
         FIG. 3  is an enlarged, front view of the electronic device of  FIG. 2 , with the panel removed. 
         FIG. 4  is a schematic, isometric view of a related-art electronic device. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Referring to  FIG. 1 , an electronic device is disclosed. The electronic device  10  is, as an example, a digital photo frame. The photo frame  10  includes a panel  20  and a display  30  mounted on the panel  20 . The panel  20  defines a light area  40 . The light area  40  is strip-shaped and normally unlit. 
     Referring to  FIGS. 2 and 3 , the panel  20  includes a transparent main body  21 , an optical clear coating layer  22 , and a light tight coating layer  23 . The optical clear coating layer  22  is painted on the main body  21 . The light tight coating layer  23  is painted on the optical clear coating layer  22  without covering the light area  40 . 
     The electronic device  10  further includes a light guide  70  beneath the panel  20  configured for filling up the whole light area  40 , and light sources  60  for illuminating the light guide  70 . In this embodiment, the electronic device  10  further includes a base plate  50  disposed between the panel  20  and the light guide  70 . 
     The base plate  50  defines an opening  52  corresponding to the light area  40 . The light guide  70  is made of transparent material or semi-transparent material. The light guide  70  covers the opening  52 . Light sources  60 ,  61  are mounted on the base plate  50 . The number and types of the light sources  60 ,  61  can be changed if necessary. In this embodiment, the light sources  60  are two light emitting diodes (LED) which are capable of emitting unidirectional light. The light sources  60  are mounted adjacent to two ends of the light guide  70 . The light source  61  is an LED capable of emitting light over a large angle. The light source  61  is mounted adjacent to a middle part of the light guide  70 . 
     When having been turned on, the light sources  60 ,  61  emit light towards the light guide  70 . The emitted light is mixed in the light guide  70  and the light guide  70  is evenly lighted. Based on the light area  40  and the opening  52 , the evenly lighted light guide  70  can be seen out of the electronic device  10 . In this way, the light area  40  of the electronic device  10  is evenly lit. 
     Moreover, it is to be understood that the invention may be embodied in other forms without departing from the spirit thereof. Thus, the present examples and embodiments are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.