Patent Publication Number: US-2005122742-A1

Title: Led lamp tube

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a LED lamp tube and, more particularly, to a power-saving, durable LED lamp tube, which comprises a specially designed tubular transparent light-guide shade and a LED module mounted inside the light-guide shade and controlled by a programmable controller to produce a lighting effect.  
      2. Description of the Related Art  
      Advertising signboards are commonly seen in streets, outside walls of buildings. These advertising signboards may be internally or externally mounted with lighting fixtures to produce a lighting effect that attracts people&#39;s eyes.  
      However, regular lighting fixtures such as neon lamps, incandescent lamps and bulbs, and recently developed high intensity discharge bulbs commonly consume much electric energy when turned on. Further, these lighting fixtures also product much heat energy during illumination, which heat energy may cause the materials of the signboards to change the quality. Lighting fixtures may fail due to excessively high temperature.  
     SUMMARY OF THE INVENTION  
      The present invention has been accomplished to provide a LED lamp tube that eliminates the aforesaid drawbacks. It is therefore the main object of the present invention to provide a LED lamp tube, which is power-saving, easy to install, durable in use, and controllable by a programmable controller to produce different lighting patterns.  
      To achieve this and other objects of the present invention, the LED lamp tube comprises a light-guide shade, and a light source mounted inside the light-guide shade. The light-guide shade comprises a light guide layer, two mounting portions extended from two opposite sides of the light guide layer for mounting, and a plurality of protruding portions arranged inside the light guide layer and defining each a respective light guiding groove for producing a respective luminous arc when radiated with light. The light source comprises a circuit board mounted inside the light-guide shade, and a plurality of light emitting diodes mounted in the circuit board and adapted to emit light onto the light guiding grooves of the protruding portions to further produce luminous arcs. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1-1  is an exploded view of a LED lamp tube according to the present invention.  
       FIG. 1-2  is an enlarged view of part A of  FIG. 1-1 .  
       FIG. 2  is a schematic side view of the LED lamp tube according to the present invention.  
       FIG. 3  is a schematic drawing showing the lamination of the LEDs in the light-guide shade according to the present invention.  
       FIG. 4  is a schematic drawing showing luminous arcs produced at the light-guide shade according to the present invention.  
       FIG. 5-1  is similar to  FIG. 2  but showing the light source adjusted to a relatively higher position.  
       FIG. 5-2  is similar to  FIG. 5-1  but showing the light source adjusted to a top position.  
       FIG. 6  illustrates a semitransparent photo mask coated on the outside wall of the light-guide shade according to the present invention.  
       FIG. 7  is a schematic drawing showing the LED lamp tube used with a reflector according to the present invention.  
       FIG. 8  is a schematic drawing showing a number of LED lamp tubes mounted with reflectors in a lamp box according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring to  FIGS. 1-1  and  1 - 2 , a LED lamp tube is shown comprised of a light-guide shade  1 , and a light source  2  mounted inside the light-guide shade  1 .  
      The 1 light-guide shade  1  can be molded from transparent or opaque plastics, having a light guide layer  11 , two mounting portions  12  extended from two opposite sides of the light guide layer  11  for enabling the light-guide shade  1  to be fastened to a lamp box (not shown) or floor panel, protruding portions  13  arranged on the inside wall of the light guide layer  11  (the protruding portions  13  can be made to form a serrated, arched, corrugated, or spiral structure on the inside the light guide layer  11 ) and defining each a respective light guiding groove  14  for producing luminous arcs, and at least one, for example, two linear coupling grooves  15  and  15 ′ bilaterally provided on the inside wall of the light-guide shade  1  for receiving the light source  2 .  
      The light source  2  comprises a circuit board  21 , and a plurality of LEDs (light emitting diodes)  22  mounted in the circuit board  21  and controlled by a control circuit (not shown) at the circuit board  21  to produce a lighting effect. The LEDs  22  may have one single color, or different colors.  
      Referring to  FIGS. 2-4 , the circuit board  21  of the light source  2  is mounted in the coupling grooves  15  and  15 ′, and then connected to power source. When electrically connected, the control circuit of the circuit board  21  controls the LEDs  22  to emit light  3  onto the light guiding grooves  14  at the protruding portions  13 , thereby causing luminous arcs  4  to be produced at the light-guide shade  1  for illumination as well as for causing a sense of beauty.  
      Referring to  FIGS. 5-1  and  5 - 2 , pairs of coupling grooves  15  and  15 ′ may be provided inside the light-guide shade  1  at different elevations for selectively receiving the light source  2 . Therefore, the light source  2  can be mounted inside the light-guide shade  1  in one of a series of positions selectively.  
      Referring to  FIG. 6 , a colored, or colorless, or frosted semitransparent photo mask  5  may be coated on the outside wall of the light-guide shade  1  to soften light from the LEDs  22 .  
      Referring to  FIG. 7 , a reflector  6  may be provided outside the light-guide shade  1  to reflect light passing through the light-guide shade  1  toward a specific direction.  
       FIG. 8  shows an application example of the present invention. According to this application example, multiple LED lamp tubes are mounted with reflectors  6  inside a lamp box  7 .  
      Further, the circuit board  21  of the light source  2  can be connected to an external control device, for example, DMX controller or personal computer that controls the lighting pattern of the LEDs  22 . Electric connectors may be used to electrically connect the circuit board  21  of the light source  2  to external devices or circuit boards for easy installation and maintenance.  
      Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.