Abstract:
A flat display, a flat panel display and a backlight module are disclosed. The flat display module comprises the flat panel display and the backlight module. The flat panel display comprises an upper polarizer and a lower polarizer. The lower polarizer includes a first diffusion layer. The backlight module comprises a light emitting device, a prism sheet and a light guide plate. A light beam is provided by the light emitting device. The prism sheet is one-dimensional prism array structure. The light guide plate includes a second diffusion layer for diffusing the light beam. The first diffusion layer has an optical haze greater than the optical haze of the surface of the upper polarizer. Accordingly, thin thickness and high brightness are achieved for the flat display.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention generally relates to a flat display, and more particularly to a flat display, a flat panel display and a backlight module, which includes a polarizer and a light guide plate.  
       BACKGROUND OF THE INVENTION  
       [0002]     Recently, thin display panels are applied for home appliances, communication apparatuses and computer apparatuses. A panel for use in a notebook computer could satisfy thin thickness and high brightness. In the prior arts, a prism sheet is usually assembled in a backlight module to concentrate light beam energy on an elevation angle by using a refraction way. Diffusion sheets are added at an upper portion or a lower portion of the prism sheet to uniform the light beam, thereby improving high brightness.  
         [0003]     Referring to  FIG. 1 , a schematic diagram illustrates a conventional flat display module. The flat display module  10  includes a flat panel display  11  and a backlight module  12 . The flat panel display  11  includes an upper polarizer  111 , a lower polarizer  112 , an upper substrate  113  and a lower substrate  114 . The backlight module  12  includes a lamp  121 , a first prism sheet  122 , a second prism sheet  123 , a light guide plate  124 , a lamp reflection cap  125 , a reflection sheet  126 , a first diffusion sheet  127  and a second diffusion sheet  128 . The lamp  121  is for providing a light beam. The first prism sheet  122  and the second prism sheet  123  are for reflecting or refracting the light beam in order to concentrate light beam energy on an elevation angle. The light beam is guided by the light guide plate  124  into the second diffusion sheet  128 . The first diffusion sheet  127  and the second diffusion sheet  128  are for diffusing the light beam. The lamp reflection cap  125  surrounds the lamp tube  121  and is placed at a side of the light guide plate  124  for reflecting the light beam to the light guide plate  124 . The reflection sheet  126  is arranged under the light guide plate  124  for reflecting the light beam to the light guide plate  124 .  
         [0004]     However, more optical sheets added into the backlight module would increase assembly time and are difficult in fastening. The weight and the thickness of a panel are further increased because the number of the optical sheets is also increased. In addition, the diffusion sheet may produce creases due to heat generated by the lamp. Therefore, a technique is then disclosed by removing the upper diffusion sheet and the lower diffusion sheet to reduce the weight and the thickness. However, uniformity of the backlight module may be decreased when diffusion sheets are removed. Shortcomings include surface deterioration, dirt and luminescent spots.  
         [0005]     The inventor of the present invention based on years of experience on related research and development of the flat panel display invents flat display, a flat panel display and a backlight module to overcome the foregoing shortcomings.  
       SUMMARY OF THE INVENTION  
       [0006]     Accordingly, an object of the present invention is to provide a flat display with thin thickness and high brightness.  
         [0007]     In accordance with the present invention a flat display includes a flat panel display and a backlight module. The flat panel display includes an upper polarizer and a lower polarizer. The lower polarizer has a first diffusion layer. The first diffusion layer has an optical haze greater than the optical haze of a surface of the upper polarizer. The backlight module includes a light emitting device, a first prism sheet and a light guide plate. The light emitting device provides a light beam. The first prism sheet has a one-dimensional prism array structure formed on a surface thereof. The light guide plate has a second diffusion layer for diffusing the light beam. The first diffusion layer has an optical haze greater than the optical haze of a surface of the upper polarizer  
         [0008]     Other features and advantages of the present invention and variations thereof will become apparent from the following description, drawings, and claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a schematic diagram illustrating a conventional flat display module;  
         [0010]      FIG. 2  is a schematic diagram illustrating a flat display according to an embodiment of the present invention;  
         [0011]      FIG. 3  is a schematic diagram illustrating a flat display according to a preferred embodiment of the present invention;  
         [0012]      FIG. 4  is a schematic diagram illustrating a flat display according to another preferred embodiment of the present invention;  
         [0013]      FIG. 5  is a schematic diagram illustrating a flat display according to a further preferred embodiment of the present invention;  
         [0014]      FIG. 6   a  is a perspective drawing illustrating a prism sheet according to an embodiment of the present invention; and  
         [0015]      FIG. 6   b  is another perspective drawing illustrating the orthogonal arrangement for the first prism sheet and that of the second prism sheet according to an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]     To make it easier for our examiner to understand the objective of the invention, its innovative features and performance, a detailed description and technical characteristics of the present invention are described together with the drawings as follows.  
         [0017]     Referring to  FIG. 2 , a schematic diagram illustrates a flat display according to an embodiment of the present invention. The flat display  20  includes a flat panel display  21  and a backlight module  22 . The flat panel display  21  includes an upper polarizer  111 , a lower polarizer  212 , an upper substrate  113  and a lower substrate  114 . The lower polarizer  212  has a first diffusion layer  213 . The first diffusion layer  213  has an optical haze greater than the optical haze of a surface of the upper polarizer  111 . The first diffusion layer  213  has the optical haze between 20% and 60%. The upper polarizer  111  has a rough surface. A surface of the upper polarizer  111  is a lens.  
         [0018]     The backlight module  22  includes a light emitting device  221 , a prism component  222 , a light guide plate  223 , a reflection cap  224  and a reflection sheet  126 . The light emitting device  221  is for providing a light beam. The prism component  222  is for reflecting or refracting the light beam. The light beam is guided by the light guide plate  223  into the prism component  222 . The light guide plate  223  has a second diffusion layer  226  for diffusing the light beam. The reflection cap  224  surrounds the light emitting device  221  and is placed at a side of the light guide plate  223 . The reflection cap  224  is for reflecting the light beam to the light guide plate  223 . The reflection sheet  126  is arranged under the light guide plate  223  for reflecting the light beam to the light guide plate  223 . The light emitting device  221  is a lamp. The prism component  222  is a prism sheet. The prism sheet has a one-dimensional prism array structure formed on a surface thereof for reflecting or refracting the light beam. Prism direction of the one-dimensional array structure is upward or downward. It should be noted the prism direction of the one-dimensional array structure as shown in  FIG. 2  is upward. The second diffusion layer  226  has an optical haze between 50% and 95%. The second diffusion layer  226  has a rough surface or diffusion particles or dot patterns on a surface of the second diffusion layer  226 .  
         [0019]     Referring to  FIG. 3 , a schematic diagram illustrates a flat display according to a preferred embodiment of the present invention. The flat display  30  includes a flat panel display  31  and a backlight module  32 . The flat panel display  31  includes an upper polarizer  111 , a lower polarizer  212 , an upper substrate  113  and a lower substrate  114 . The lower polarizer  212  has a first diffusion layer  311 . The first diffusion layer  311  has an optical haze greater than the optical haze of a surface of the upper polarizer  211 . The first diffusion layer  311  has the optical haze between 20% and 60%. The upper polarizer  111  has a rough surface.  
         [0020]     The backlight module  32  includes a lamp  321 , a first prism sheet  324 , a light guide plate  325 , a lamp reflection cap  322  and a reflection sheet  126 . The lamp  321  is for providing a light beam. The first prism sheet  324  has a one-dimensional prism array structure formed on a surface thereof for reflecting or refracting the light beam. Prism direction of the one-dimensional prism array structure is upward. The light beam is guided by the light guide plate  325  into the first prism sheet  324 . The light guide plate  325  has a second diffusion layer  323  for diffusing the light beam. The second diffusion layer  323  has an optical haze between 50% and 95%. The lamp reflection cap  322  surrounds the lamp  321  and is placed at a side of the light guide plate  325 . The lamp reflection cap  322  is for reflecting the light beam to the light guide plate  325 . The reflection sheet  126  is arranged under the light guide plate  325  for reflecting the light beam to the light guide plate  325 .  
         [0021]     Referring to  FIG. 4 , a schematic diagram illustrates a flat display according to another preferred embodiment of the present invention. The flat display  40  includes a flat panel display  31  and a backlight module  41 . The flat panel display  31  includes an upper polarizer  111 , a lower polarizer  212 , an upper substrate  113  and a lower substrate  114 . The lower polarizer  212  has a first diffusion layer  311 . The first diffusion layer  311  has an optical haze greater than the optical haze of a surface of the upper polarizer  111 . The first diffusion layer  311  has the optical haze between 20% and 60%.  
         [0022]     The backlight module  41  includes at least a lamp  321 , a first prism sheet  324 , a second prism sheet  411 , a light guide plate  325 , a lamp reflection cap  322  and a reflection sheet  126 . The lamp  321  is for providing a light beam. The first prism sheet  324  has a one-dimensional prism array structure formed on a surface thereof for reflecting or refracting the light beam. The second prism sheet  411  has a one-dimensional prism array structure formed on a surface thereof. Prism directions of the one-dimensional prism array structure of the first prism sheet  324  and that of the second prism sheet  411  are upward. The one-dimensional prism array structure of the first prism sheet  324  and that of the second prism sheet  411  are orthogonal. The light beam is guided by the light guide plate  325  into the second prism sheet  411 . The light guide plate  325  has a second diffusion layer  323  for diffusing the light beam. The second diffusion layer  323  has an optical haze between 50% and 95%. The lamp reflection cap  322  surrounds the lamp  321  and is placed at a side of the light guide plate  325  for reflecting the light beam to the light guide plate  325 . The reflection sheet  126  is arranged under the light guide plate  325  for reflecting the light beam to the light guide plate  325 .  
         [0023]     Referring  FIG. 5 , a schematic diagram illustrates a flat display according to a further preferred embodiment of the present invention. The flat display  50  includes a flat panel display  31  and a backlight module  51 . The flat panel display  31  includes an upper polarizer  111 , a lower polarizer  212 , an upper substrate  113  and a lower substrate  114 . The lower polarizer  212  has a first diffusion layer  311 . The first diffusion layer  311  has an optical haze grater than the optical haze of a surface of the upper polarizer  111 . The first diffusion layer  311  has the optical haze between 20% and 60%.  
         [0024]     The backlight module  51  includes at least one lamp  321 , a third prism sheet  511 , a light guide plate  325 , a lamp reflection cap  322  and a reflection sheet  126 . The lamp  321  is for providing a light beam. The third prism sheet  511  has a one-dimensional prism array structure formed on a surface thereof for reflecting or refracting the light beam. Prism direction of the one-dimensional prism array structure of the third prism sheet  511  is downward. The light beam is guided by the light guide plate  325  into the third prism sheet  511 . The light guide plate  325  has a second diffusion layer  323  for diffusing the light beam. The second diffusion layer  323  has an optical haze between 50% and 95%. The lamp reflection cap  322  surrounds the lamp tube  321  and is placed at a side of the light guide plate  325  for reflecting the light beam to the light guide plate  325 . The reflection sheet  126  is arranged under the light guide plate  325  for reflecting the light beam to the light guide plate  325 .  
         [0025]     In  FIG. 4 , the arrangement for the first prism sheet  324  and the second prism sheet  411  is orthogonal. The orthogonal relation can be shown in  FIG. 6   a  and  FIG. 6   b .  FIG. 6   a  is a perspective drawing illustrating a prism sheet according to an embodiment of the present invention.  FIG. 6   b  is another perspective drawing illustrating the orthogonal relation for the first prism sheet and the second prism sheet according to an embodiment of the present invention. The first prism sheet  324  is placed above the second prism sheet  411 . The first prism sheet  324  has a plurality of triangle posts  3241  and a substrate  3242 . The plurality of triangle posts  3241  is a wedge structure and is set on the substrate  3242 . The arrangement of the plurality of triangle posts  3241  is mutual parallel arrangement. The second prism sheet  411  can also have a plurality of triangle posts  4111  the same as the first prism sheet. The plurality of triangle posts is a wedge structure. The arrangement for the plurality of triangles posts  4111  is a mutual parallel arrangement. However, the aforesaid arrangements for the first and the second prism sheets  324 ,  411  are formed ninety degree with orthogonal arrangement as illustration in  FIG. 4 . In another word, although the prism directions of the one-dimensional prism array structure are upward, the plurality of triangle posts  3241  of the first prism sheet  324  is vertical the plurality of triangle posts  4111  of the second prism sheet  411 . Furthermore, the bottom of the substrate  3242  of the first prism sheet  324  corresponds to an apex  4112  of each triangle post of the second prism sheet  411 . (Each triangle post has two inclination surfaces, which are extended from two hemlines of the bottom of each triangle post.)  
         [0026]     Moreover, another flat display comprises a flat panel display and a backlight module. The flat panel display has an upper polarizer, a lower polarizer and a first diffusion layer. The first diffusion layer is disposed on the lower polarizer. The first diffusion layer has an optical haze greater than the optical haze of a surface of the upper polarizer. The backlight module has a light emitting device, a first prism sheet and a light guide plate. The light emitting device provides a light beam. The first prism sheet has a one-dimensional prism array structure formed on a surface thereof for reflecting or refracting the light beam. The light guide plate has a second diffusion layer for diffusing the light beam  
         [0027]     In addition, a further flat display comprises a flat panel display and a backlight module. The flat panel display has an upper polarizer and a lower polarizer. The lower polarizer has a first diffusion layer. The first diffusion layer has an optical haze greater than the optical haze of a surface of the upper polarizer. The backlight module has a light emitting device, a first prism sheet, a light guide plate and a second diffusion layer. The second diffusion layer is disposed on the light guide plate. The light emitting device provides a light beam. The first prism sheet has a one-dimensional prism array structure formed on a surface thereof for reflecting or refracting the light beam. The second diffusion layer is for diffusing the light beam. Both the first diffusion layer and the second diffusion layer can be disposed or formed on the lower polarizer and the light guide plate.  
         [0028]     The embodiment further considers the match of the transmittance axis direction of the lower polarizer  212  and the alignment axis of the third prism sheet  511 . The transmission axis direction of the lower polarizer  212  usually includes 45 degree or 135 degree. To obtain better luminance and to reduce luminance variation for the flat display  50 , the third prism sheet  511  between 45 degree and 90 degree of the alignment axis then is selected to match with the lower polarizer at 45 degree of the transmittance axis direction, and the third prism sheet  511  between 90 degree and 135 degree of the alignment axis is selected to match with the lower polarizer at 135 degree of the transmittance axis direction. The luminance is therefore enhanced and the luminance variation is reduced.  
         [0029]     While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.  
         [0030]     In summation of the description above, the present invention is novel and useful and definite enhances the performance over the conventional structure and further complies with the patent application requirements and is submitted to the Patent and Trademark Office for review and granting of the commensurate patent rights.