Abstract:
At least one dimmer device is provided at the spacing between abutted light sources to allow lights diffused from both sides of the light sources to be properly refracted and reflect to further evenly diffuse toward a diffuser plate thus to eliminate the dark band between abutted light sources for effectively solving the significantly present bright band and dark band of the LCD module observed with the prior art.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention is related to an improved structure of a backlight module dimmer device, and more particularly to one that effectively distribute lights from light sources without developing bright band and dark band.  
         [0003]     2. Description of the Prior Art  
         [0004]     As illustrated in  FIG. 1  (A) of the accompanying drawings for an improved structure of a LCD backlight module of the prior art, the backlight module is essentially comprised of a reflector mask  10 , multiple light sources  20 , a diffuser plate  30 , a lower diffuser sheet  40 , a prism  50 , a reflective polarizing sheet or an upper diffuser sheet  60  and a LCD  70  arranged in sequence from inside out. Wherein, those light sources  20  may be each a light tube in a stripe, U-shape or other continuously curve and arranged at a proper spacing between the reflector mask  10  and the diffuser plate  30  and the lights emitted by each of those light sources  20  provide the display effects by the LCD module. As generally found available in the market, multiple optical films disposed between the diffuser  30  and the LCD module may be comprised of 1˜3 diffuser sheets, 0˜2 brightness enhancement films and one reflective polarizing sheet with the purpose of creating diffusion for the lights passing through those optical films so to correct the phenomena of bright band and dark band formed on the LCD module due to the absence of light emitted to where between any abutted light sources.  
         [0005]     Where as the diffuser plate  30  functions only to help achieve the even diffusion for lights passing through it, it has a limited efficiency in correcting the phenomenon of the bright band and the dark band observed on the LCD module. To this, an improvement is made for certain backlight modules by having extended on purpose the distance between those light source  20  and the diffuser plate  30  in the hope of widening the scope of each of those light sources  20  entering into the diffuser plate  30  to achieve the purpose of reducing the dark band. However, the structural design for such an improvement not only provides limited effects but also results in that the backlight module must be made thicker to fail the compact requirements of the LCD module.  
         [0006]     Furthermore, some other backlight modules seeks to provide extinction (dispersion) on the surface of the diffuser plate by printing on the diffuser plate with ink containing SiO 2  or TiO 2  to achieve the purpose of reducing the dark band. Again, the extinction process not only increases the production cost of the diffuser and the complexity of the manufacturing process, but also relates to a passive solution to reduce the dark band on LCD since the extinction is created only after the light lands on the surface of the diffuser.  
         [0007]     Further improvement as illustrated in FIG. (B), multiple dimmer devices  12  are provided on the reflector mask  10  of the backlight module. The highly reflective surface of the dimmer device  12  reflects the light emitted from the light source to eliminate the dark band between any abutted light sources. However, the dimmer  12  integrated with the reflector mask  10  functions only the purpose of reflective dimming and fails to provide refractive or diffusive dimming function.  
       SUMMARY OF THE INVENTION  
       [0008]     The primary purpose of the present invention is to provide an improved structure of a dimmer device to actively and effectively solve the problems of the significant bright band and dark band observed with the LCD module of the prior art to more effectively distribute the lights emitted form the light sources. To achieve the purpose, one or more than one dimmer device is disposed between the spacing between light sources to evenly diffuse the lights diffused from both sides of the light sources towards the diffuser plate after having been properly refracted and reflected, thus to eliminate the dark band between any abutted light sources. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1 (A) is a sectional view of the structure of a backlight module of the prior art.  
         [0010]      FIG. 1 (B) is a sectional view of the structure of another backlight module of the prior art.  
         [0011]      FIG. 2  is a sectional view of a backlight module of a first preferred embodiment of the present invention.  
         [0012]      FIG. 3  is a sectional view of a backlight module of a second preferred embodiment of the present invention.  
         [0013]      FIG. 4  is a sectional view of a backlight module of a third preferred embodiment of the present invention.  
         [0014]      FIG. 5  is a sectional view of a backlight module of a fourth preferred embodiment of the present invention.  
         [0015]      FIG. 6  is a sectional view of a backlight module of a fifth preferred embodiment of the present invention.  
         [0016]      FIG. 7  is a sectional view of a backlight module of a sixth preferred embodiment of the present invention.  
         [0017]      FIG. 8 (A) is a sectional view of a backlight module of a seventh preferred embodiment of the present invention.  
         [0018]      FIG. 8 (B) is a sectional view of a backlight module of an eighth preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]     Referring to  FIG. 2 , a first preferred embodiment of the present invention is essentially comprised of the backlight module is essentially comprised of a reflector mask  10 , multiple light sources  20 ,a diffuser plate  30 , a lower diffuser sheet  40 , a prism  50 , a reflective polarizing sheet or an upper diffuser  60  and a LCD  70  arranged in sequence from inside out. Wherein, those light sources  20  may be each a light tube in a stripe, U-shape or other continuously curve and arranged at a proper spacing between the reflector mask  10  and the lower diffuser sheet and the lights emitted by each of those light sources  20  provide the display effects by the LCD.  
         [0020]     One or more than one solid or hollow dimmer device  80  is provided at where between any abutted light sources  20 . In a first preferred embodiment of the present invention as illustrated in  FIG. 2 , the dimmer device  80  is made in a structure of stick bounded to the reflector mask  10 , or in a second preferred embodiment as illustrated in  FIG. 3 , an insertion mechanism  100  is provided on the dimmer device  80  to be incorporated to the reflector mask  10  or the mechanism below the reflector mask  10  for the dimmer device to be firmly secured to a proper position on the reflector mask  10 . The insertion mechanism  100  is provided with a locking pin  91  at where between the dimmer device  80  is bounded to the reflector mask  10  while a locking hole  11  is provided to the reflector mask  10  in relation to the respectively locking pin  81  for the dimmer device  80  and the reflector mask  10  to lock to each other. Alternatively, an insertion member may be separately provided to lock the dimmer device  80  and the reflector mask  10  by means of adhesion, insertion or a screw. As illustrated in  FIG. 4  for a third preferred embodiment, the insertion mechanism  100  is disposed with a threaded hole  92  between where the dimmer device  80  is bounded to the reflector mask  19  while the locking hole  11  is provided on the reflective mask  10  to permit the insertion of a screw  90  to fasten the dimmer device  80  to the reflector mask  10  or the mechanism below the reflector mask  10 .  
         [0021]     Whereas the dimmer device  80  of the present invention is provide between any abutted light sources  20 , the lights diffused from both sides of the light source passing through is properly refracted and reflected by the dimmer device  80  before being evenly diffused towards the diffuser plate  30  to provide an active means in eliminating the dark band created between abutted sources for more effectively distributing lights emitted from the light source.  
         [0022]     The dimmer device  80  may be made of plastic materials including but not limited to Polycarbonate (PC), or Polymethyl methacrylate (PMMA), or Polyethylene Terephthalate (PET) in to a white or transparent stick structure, or made of transparent plastic materials, e.g. PC or PMMA added with diffusion agent (such as SiO2 or TiO2) in a white mat stick structure so to produce the dimmer device  80  with various refraction effects for the selection of the proper dimmer device  80  depending on the spacing between the backlight module and the light source  20 .  
         [0023]     Now referring to  FIG. 5  for a fourth preferred embodiment of the present invention, wherein, at least one surface of the dimmer light device  80  is locally or entirely distributed with embossment  83  in a form of V-, U-, or C-shaped cut, or multiple straight lines or curves or combination of both on the surface facing the lower diffuser plate  30  and the light source  20  in the fourth preferred embodiment of the present invention; or as illustrated in  FIG. 6  for a fifth preferred embodiment of the present invention, wherein, multiple convex surfaces in various curvatures  84  are disposed. The dimmer device  80  is formed by a different convexor flat surface for the embossment  83  or the convex surface to create light converging effect. Alternatively, as illustrated in  FIG. 7  for a sixth preferred embodiment of the present invention, various changes in the shape and the distance of the arrangement are feasible depending on the size of the light source  20  or the length of the spacing between a butted light sources  20 . The shape of the dimmer device  80  varies depending on the angle of the disposition of the light source  20  as illustrated in FIGS.  8 (A) and  8 (B) respectively of a seventh and an eighth preferred embodiments of the present invention; wherein, either the appearance, size or shape of those dimmer devices  80  are continuously changed so that the lights emitted form the light source  20  can be diffused from the embossment  83  or the convex surface  84  on the diffuser plate  30  to more effectively solve the problem of the significant bright band and dark band of the LCD module of the prior art. Alternatively, the same effects can be achieved by having at least one surface of the dimmer device  80  locally or entirely matted, or printed with ink, or distributed with concave and convex points in either round, rectangular, diamond or polygonal form.  
         [0024]     The present invention provides an improved structure of a dimmer device for a LCD module and this application is duly filed for a utility pattern. It should be noted that the specification and drawings are provided as one of the preferred embodiments of the present invention and do not in any way limit the present invention. Therefore, any structure, device, and/or characteristics similar or equivalent to that of the present invention shall be deemed as falling within the scope of the purpose and claims made by the present invention.