Patent Publication Number: US-2015062865-A1

Title: Indicating light for transportation

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an indicating light, and more particularly to an indicating light for transportation. 
     2. Description of the Prior Art 
     With the advantage of low power consumption, LEDs have been popularly applied on different objects in people&#39;s lives, for example, LED indicating lights for bicycles. The LEDs have characters of small beam angle and high directionality to enhance efficiency of light concentrating and get high luminance However, in another aspect, the LEDs will easily cause irritating glare to human eyes and are difficult to generate a wide-angle (&gt;120 degrees) and uniform illumination area. Therefore, the LED light often utilizes multiple LEDs arranged in a circular shape to increase the uniform illumination of a wide angle. 
     In addition to changing the arrangement of the LEDs, as the LED light usually has a transparent lid covering and protecting the LEDs, the illumination performance of the LED light can be improved by modifying the structure of the transparent lid. For example, on an inner surface of the transparent lid, multiple small protrusions can be formed to provide a refraction effect for a wide angle illumination. 
     For the design of traditional LED light, it is still difficult to get a uniform illumination of a wide angle without irritating glare by arrangement of LED or optical design of lid covering. 
     SUMMARY OF THE INVENTION 
     An objective of the present invention is to provide an indicating light for transportation, wherein the indicating light provides a curved or a flat surface light effect for overcoming the glare problem, achieving a wide angle illumination and increasing illumination area. 
     The indicating light for transportation comprises a circuit board, a reflective layer and a light guide plate. 
     The light guide plate has at least one edge, an inner surface attached to the reflective layer and facing toward the circuit board, an outer surface opposite to the inner surface, and an indicating portion formed on the inner surface of the light guide plate. 
     The circuit board has a surface and multiple LEDs mounted on the surface of the circuit board, wherein each LED has a light emitting surface facing the at least one edge of the light guide plate, and light generated by the LEDs is reflected or refracted to the outer surface by the indicating portion. 
     The reflective layer is sandwiched between the circuit board and the light guide plate for reflecting the light of the LEDs. 
     After the circuit board, the reflective layer and the light guide plate are sequentially mounted together, and the LEDs emit light toward the edge of the light guide plate. The light of the LEDs is guided into the light guide plate and the directivity of the light is changed by the indication portion to produce a surface light effect. Therefore, the illuminating angle and illuminating area will be increased, and the glare problem will also be mitigated. 
     Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of an indicating light of the present invention; 
         FIG. 2  is a perspective view of the indicating light of the present invention; 
         FIG. 3  is an exploded perspective view of the indicating light of  FIG. 2 ; 
         FIG. 4  is a cross sectional view showing a part of the indicating light of the present invention, wherein the light emitted from the LEDs is reflected by the indicating portion of the light guide plate; 
         FIG. 5  is an operational view of the indicating light of the present invention being mounted on a bicycle frame; 
         FIG. 6  is another operational view of the indicating light of the present invention; 
         FIG. 7  is still another operational view of the indicating light of the present invention, wherein the indicating light has an indicating portion of an animal pattern; and 
         FIG. 8  is another exploded perspective view of the indicating light of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1 to 3 , a first embodiment of an indicating light  10  of the present invention comprises a circuit board  20 , a reflective layer  30  and a light guide plate  40 . The reflective layer  30  and the light guide plate  40  are sequentially attached to the circuit board  20  and are sheet-shaped. As shown in  FIG. 1 , the circuit board  20 , the reflective layer  30  and the light guide plate  40  are flat sheets. As shown in  FIGS. 2 and 3 , the circuit board  20 , the reflective layer  30  and the light guide plate  40  may have flexibility and are in forms of curved sheets. For example, the circuit board  20 , the reflective layer  30  and the light guide plate  40  can be bent to have an S-shaped cross section, a V-shaped cross section, a U-shaped cross section or a circular cross section. 
     The circuit board  20  is rectangular and has a surface, two long edges and two short edges. Multiple LEDs  21  are mounted on the surface of the circuit board  20  and controlled by the circuit board  20  to generate different lighting effects such as changing colors and flickering. The LEDs  21  are separated from one another and may be distributed along the two long edges, along the two short edges, or along one long edge and one short edge of the circuit board  20 . When the LEDs  21  are mounted along the two long edges or the two short edges, the LEDs  21  located at one edge may align or misalign with the LEDs  21  located at the opposite edge. 
     As shown in  FIG. 2 , the LEDs  21  are distributed in two rows respectively along the two long edges of the circuit board  20 , wherein light emitting surfaces  211  of the LEDs  21  at one edge face toward light emitting surfaces  211  of the LEDs  21  at the opposite edge. 
     In another embodiment, when the circuit board  20  has a circular shape, the LEDs  21  can be arranged along the edge of the circuit board  20 . If the circuit board  20  has a polygonal shape, the LEDs  21  may be arranged along any two or more than two edges of the circuit board  20 . The circuit board  20  is not limited to a specific shape, and can be modified by demand. An external power module may be connected to the circuit board  20  for supplying operating voltages to the circuit board  20  and the LEDs  21 . 
     The reflective layer  30  is a thin and rectangular layer with two long edges in this embodiment. A distance D 1  between the two long edges of the reflective layer  30  is smaller than a distance D 2  between the two rows of the LEDs  21 . The reflective layer  30  is provided on the surface of the circuit board  20  and between the two rows of the LEDs  20 . The reflective layer  30  may be a separate element mounted on the circuit board  20 , a film formed by a film-coating process on the surface of the circuit board  20 , or a film formed by the film-coating process on a surface of the light guide plate  40  facing the circuit board  20 . 
     At least one edge of the light guide plate  40  faces the light emitting surfaces  211  of the LEDs  21 . The light guide plate  40  has an inner surface and an outer surface, wherein the inner surface faces toward the reflective layer  30  and the outer surface is opposite to the inner surface. On the inner surface of the light guide plate  40 , an indicating portion  41  is formed by a plurality of concave dents or protruding bumps 
     With reference to  FIG. 4 , the indicating portion  41  in this embodiment is formed by a plurality of concave dents as light guide structures for reflecting or refracting light generated by the LEDs  21  to the outer surface of the light guide plate  40 . Furthermore, the light of the LEDs  41  is also reflected to the outer surface of the light guide plate  40  by the reflective layer  30 . The indicating portion  41  may be formed as a character, letters, or a pattern. For example, the indicating portion  41  in  FIG. 3  is formed into five letters F, H, T, H and E. 
     In the embodiment that the indicating portion  41  is formed by a plurality of bumps, the bumps protrude from the inner surface of the light guide plate  40  and toward the reflective layer  30  and the plurality of the bumps are comprised of multiple pairs of adjacent bumps. 
     When the reflective layer  30  is formed by the film-coating process, the indicating portion  41  will be formed on the inner surface of the light guide plate  40  in advance, and then the reflective layer  30  will be coated on the inner surface of the light guide plate  40 . 
     In brief, the light generated by the LEDs  21  of the circuit board  20  emits toward the edge of the light guide plate  40 , and is guided by the indicating portion  41  for being transmitted outwardly. The reflective layer  30  is utilized to further reflect the light of the LEDs  21  to the light guide plate  40  and reduce light losing from the inner surface of the light guide plate  40 . By providing the indicating portion  41  as the light guide structure and arranging the LEDs  21  beside the light guide plate  41 , the outer surface of the light guide plate  40  will generate a surface light effect for reducing the glare and having an enlarged illuminating area. 
     With reference to  FIGS. 5 and 6 , the indicating light  10  of the present invention is to be mounted on a tube  50  of a bicycle frame. A fastening assembly  60  is applied to securely mount the indicating light  10  to the tube  50 . The fastening assembly  60  comprises a front shell  61  and two rear covers  62 . The front shell  61  is U-shaped in cross section and forms an opening  612  and multiple threaded holes  611 . The opening  612  is formed through a central portion of the front shell  61  and is large enough to expose the character or pattern formed by the indicating portion  41 . Each rear cover  62  is also U-shaped and has two through holes  621 . The rear covers  62  are fastened to the front shell  61  by screws  622  through the through holes  621  and then are fixed in the threaded holes  611 . Thus, the tube  50  together with the indicating light  10  are held between the front shell  61  and the rear covers  62 . 
     With reference to  FIG. 7 , the indicating portion  41  is formed as a pattern of an animal, and the light guide plate  40  is replaceable for changing the pattern of the indicating portion  41 . 
     With reference to  FIG. 8 , the indicating light  10  further comprises two reflective strips  70 . The two reflective strips  70  are mounted on the outer surface of the light guide plate  40  and are respectively aligned with the opposite edges of the light guide plate  40  and adjacent to the two rows of the LEDs  41 . When the light emitted by the LEDs  41  passes through the light guide plate  40 , the reflective strips  70  can further reflect the light to increase brightness of the light guide plate  40 . 
     Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, 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.