Patent Publication Number: US-2007121081-A1

Title: Projection lighting device

Description:
FIELD OF THE INVENTION  
      The present invention relates to a projection lighting device, and more particularly, to a compact vehicle lighting device using light emitting diodes.  
     BACKGROUND OF THE INVENTION  
      A conventional projection lighting device  1  for vehicles is shown in  FIGS. 1 and 2 , and generally includes a light source unit  11  having a bulb  111  and a reflection member  112  wherein the bulb  111  is located at a first focus  2  of the reflection member  112  and the light beams from the bulb  111  are reflected by the reflection member  112  and focused at a second focus  3  and then go through the lens  12 .  
      Thanks to the modern industry of semi-conductive chips, light emitting diodes are developed to a new level and able to provide high illumination with less energy consuming. The light emitting diodes are small and light in weight, have short response time and bear vibration. The light emitting diodes are used to be lighting device recently. As shown in  FIG. 3 , the projection lighting device  4  includes a light source unit  41  and a lens  42 , wherein the light source unit  41  includes a board  411  and the light emitting diode  412  is connected to board  411 , and a reflection member  41  is put on the designed position with respect to the board  411 . However, multiple sets of the light source units  41  have to be used to provide a required quality light output for the vehicle lighting device. The multiple sets of the light source units  41  occupy too much space.  
      The present invention intends to provide a compact sized lighting device using light emitting diodes.  
     SUMMARY OF THE INVENTION  
      The present invention relates to a projection lighting device that comprises a light source unit having a board having at least two light emitting diodes connected thereto. A reflection member is put on designed position with respect to the board and includes at least two curve inner peripheries and the light emitting diodes are located within the at least two curve inner peripheries correspondingly. Two first flat surfaces are defined in two ends of the reflection member. A lens is connected to the light source unit and has at least two continuous curve surfaces. The lens has at least two continuous curve top edges and at least two continuous curve bottom edges. Two second flat surfaces are defined in two ends of the lens.  
      The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is an exploded view to show a lens and a conventional head light device;  
       FIG. 2  shows the light beams are reflected by the reflection member of the conventional lighting device;  
       FIG. 3  shows a conventional head light device including multiple sets of light emitting diodes;  
       FIG. 4  is an exploded view to show the head light device of the present invention;  
       FIG. 5  is another exploded view to show the head light device of the present invention;  
       FIG. 6  shows the relationship between the illumination of a light emitting diode and angles that the light beams orientate;  
       FIG. 7  shows a vertical cross sectional view of the reflection member and the paths that the light beams are reflected;  
       FIG. 8  shows a horizontal cross sectional view of the reflection member and the paths that the light beams are reflected;  
       FIG. 9  shows a plate is located between the light source unit and the lens, and  
       FIG. 10  shows that a part of the light beam is blocked by the plate. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring to FIGS.  3  to  5 , the projection head light device of the present invention comprises a light source unit  51  and a lens  52 , wherein the light source unit  51  includes a board  511  and two light emitting diodes  512  connected thereto. A reflection member  513  is put on designed position with respect to the board  511  and includes two curve inner peripheries, the light emitting diodes  512  are located within the two curve inner peripheries correspondingly so that the light beams from the light emitting diodes  512  are reflected by the curve inner peripheries which will be defined specifically later. Two first flat surfaces  5132  are defined in two ends of the reflection member  5113 .  
      The lens  52  is connected to the light source unit  51  and has two continuous curve surfaces  521 . The lens  52  has continuous curve top edges  522  and at least two continuous curve bottom edges  523 . Two second flat surfaces  524  are defined in two ends of the lens  52 . The lens  52  can be an aspherical lens or a Fresnel lens.  
      As shown in  FIG. 6  which shows the relationship between the illumination of the light emitting diode  512  and angles that the light beams orientate. It is clear that the illumination of the light beams are high at the center of light output direction, for example, range from −40 degrees to +40 degrees, and the wider the angle is, the less illumination the beams is. In other words, the illumination on wider angles can be omitted when using the light emitting diodes  512  to a vehicle lighting device. In order to obtain a beam that meets regulations for vehicle lighting devices, the reflection member  513  includes different horizontal cross section and vertical cross section. The reflection surface  5131  comprises multiple focuses and this multiple-focus surface  5131  is polyellipsoid reflection surface.  
       FIG. 7  shows the vertical cross section of the reflection member  513 , the light beams from the light emitting diodes  512  are reflected by the polyellipsoid reflection surface and focused at the focus  6  of the lens  52 . The light beams then go through the lens  52  or even through the top edges  522  and the bottom edges  523  of the lens  52 .  
       FIG. 8  shows the horizontal cross section of the reflection member  513 , the light beams from the light emitting diodes  512  are reflected by the polyellipsoid reflection surface and focused at a remote distance via the lens  52 . The light beams reflected by the vertical cross section and the horizontal cross section are combined to form a wide and flat range of light beam which is perfect for the head light device of vehicles.  
       FIGS. 9 and 10  show another embodiment of the present invention wherein there is a plate  7  located between the light source unit  51  and the lens  52 , wherein the plate  7  can block a part of the light beams so as to form the high beam and short beam when using for a vehicle head light device.  
      The lens  52  and the reflection member  513  each have two flat surfaces  5132 ,  524  so that the area that the lighting device occupies is reduced and more lenses  52  can be arranged in a limited area and which means more light emitting diodes  512  are installed in the head light device. Because the illumination at wider angles are weak so that the narrower lenses  52  and reflection members  513  do not affect the illumination of the lighting device.  
      While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.