Abstract:
A liquid crystal display includes a display panel, a first data circuit board, a second data circuit board, and a clip. The first data circuit board has a portion of a plurality of conductors that are coupled to the display panel. The second data circuit board has a second plurality of conductors that are coupled to the display panel. A clip couples the first and the second circuit boards together. A method of assembling the liquid crystal display includes positioning a light source; coupling a clip to the first circuit board and the second circuit board that form a display panel; positioning the clip, the first circuit board, and the second circuit board below the light source; and coupling the clip to a ground plane.

Description:
PRIORITY CLAIM  
       [0001]     This application claims the benefit of Korean Patent Application No. P2003-82949 filed in Korea on Nov. 21, 2003. The disclosure of the application is incorporated herein by reference.  
       BACKGROUND  
       [0002]     1. Technical Field  
         [0003]     This invention relates to displays, and more particularly to, a simplified assembly of a liquid crystal display that has an improved ground plane.  
         [0004]     2. Related Art  
         [0005]     In general, liquid crystal display modules include a liquid crystal display panel having liquid crystal cells positioned between two substrates. An illuminating unit may be placed behind the liquid crystal display panel to improve clarity and brighten the display panel. Optical sheets may be placed between the illuminating unit and the liquid crystal display to collect and concentrate light against the display to achieve an even greater brightness. To minimize light losses, the optical sheets may form an integral part of the liquid crystal display.  
         [0006]      FIG. 1  and  FIG. 2  illustrate a liquid crystal display module that includes a liquid crystal display panel  6 , an inner support  24 , and a case  2 . The case  2  encloses a portion of the inner support  24  and the liquid crystal display panel  6 . An illuminating unit (not shown) having a plurality of lamps is positioned behind the liquid crystal display panel  6 . A cover  14  disposed below a plurality of optical sheets receives the light that is spread across its surface.  
         [0007]     In  FIG. 1 , the liquid crystal display  6  is comprised of an upper substrate  5  and a lower substrate  3  separated by a liquid crystal layer An array of liquid crystals (not shown) injected between the upper and the lower substrates  3  and  5  polarize the light passing through it.  
         [0008]     In a matrix display, data lines, gate lines, and other components that are not shown may be formed on the lower substrate  3 . A thin film transistor (TFT) in electrical contact with a data and a gate line form one of the many liquid crystal cells that make up the display. The TFT passes data signal to the liquid crystal cell when biased by a scanning pulse (e.g., a gate pulse).  
         [0009]     In some matrix displays, a side surface of the lower substrate  3  has data and gate pads. Data circuits  8  mounted to a data drive integrated circuit  10  are electrically linked to the data lines through the data pads. Gate circuits  4  mounted to a gate drive integrated circuit  12  are electrically linked to the gate lines through the gate pads.  
         [0010]     As shown in  FIG. 2 , the first and second circuit boards  20  and  22 , and the gate circuit board  26  are positioned proximate to the support  24 . In this display, the gate circuit board is secured to the bottom cover with tape and the first and second data circuit boards  20  and  22  are secured to the bottom cover  14  by threaded screws  30  and  32  (See  FIG. 3 ). The screws  30  and  32  pass through first and second holes  34  and  36  of the first and second circuit boards  20  and  22 , respectively, before passing through fastening holes formed in the bottom cover  14 . The threaded screws  30  and  32  and bottom cover act as a ground plane for the first, second, and gate circuit boards  20 ,  22 , and  26 .  
         [0011]     Since the ground plane act as a reference for the voltages in circuit, a weak or intermittent ground may affect the display&#39;s performance. If one or more screws  30  and  32  fall out of engagement with the bottom cover  14 , the conducting path to ground decreases which may lead to display failure and a loose inner assembly. Moreover in some displays, the multiple screws must first be properly aligned before being evenly and progressively tightened to minimize circuit and board stress in the assembly process. This practice may complicate the assembly process and increases assembly time. The present inventions are directed to an improved display that overcomes some of these potential drawbacks of the related art.  
       SUMMARY  
       [0012]     A liquid crystal display comprises a display panel, a first data circuit board, a second data circuit board, and a clip. The first data circuit board supports a portion of a plurality of conductors that are coupled to the display panel. The second data circuit board has a second plurality of conductors that are coupled to the display panel. A clip couples the first and the second circuit boards together.  
         [0013]     A method of assembling the liquid crystal display includes positioning a light source; coupling a clip to the first circuit board and the second circuit board that comprise a display panel; positioning the clip, the first circuit board and the second circuit board below the light source; and coupling the clip to a ground plane.  
         [0014]     Other systems, methods, features, and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the invention, and be protected by the following claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the inventions. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views.  
         [0016]      FIG. 1  is a partial plan view of a liquid crystal display in the related art.  
         [0017]      FIG. 2  is a partial rear view of the liquid crystal display of  FIG. 1 .  
         [0018]      FIG. 3  is a partial cross-sectional view of the liquid crystal display of  FIG. 2 .  
         [0019]      FIG. 4  is an exploded perspective view of a liquid crystal display embodiment.  
         [0020]      FIG. 5  is a partial plan view of the liquid crystal display embodiment of  FIG. 4 .  
         [0021]      FIG. 6  is a rear view of the liquid crystal display embodiment of  FIG. 4 .  
         [0022]      FIG. 7  is a perspective view of a clip shown in  FIG. 4 .  
         [0023]      FIG. 8  is a perspective view of the clip shown in  FIG. 4 .  
         [0024]      FIG. 9  is a flow diagram of an assembly of a liquid crystal display embodiment. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]     A fastening device may improve the assembly and operation of a display. The fastening device may comprise any device that grips and holds boards or circuits together without threads. The fastening device may engage top surfaces of two or more circuit boards while engaging bottom surfaces of those same circuit boards. The fastening device may improve a display&#39;s mechanical durability by increasing the surface area that joins or links the boards or circuits together. The fastening device may improve the displays&#39; electrical durability by increasing the area used to dissipate electrical interference or electrical charge.  
         [0026]      FIG. 4  is an exploded view of a liquid crystal display embodiment. The liquid crystal display (LCD) includes a support main  124 , a backlight unit  160 ,  162 , 164 ,  166 , and  168 , a liquid crystal display panel  106 , and a case top  102 . The case top  102  partially encloses side portions of the support main  124  and the liquid crystal display panel  106 . In  FIG. 4 , the support main  124  is a molded product that may include side cutout portions and/or side projections. A step like ledge or shelf portion of the support main  124  supports the liquid crystal display panel  106  and the backlight unit  160 , 162 ,  164 , 166 , and  168 .  
         [0027]     The backlight unit  160 , 162 , 164 , 166 , and  168  maybe, for example, an electroluminescent device, light source, or other devices that convert electrical energy into light such as a plurality of lamps  160 . The plurality of lamps  160  maybe, for example, cold cathode florescent light sources held in place by a plurality of lamp holders  162 . A medium spreads or scatters light onto the liquid crystal display panel  106 . In  FIG. 4 , the medium comprises a diffuser  166  that is proximate to a plurality of optical sheets  168 . The optical sheets  168  are disposed between the diffuser  166  and the liquid crystal display panel  106  to collect and direct light to the liquid crystal display panel  106 .  
         [0028]     Each of the plurality of lamps  160  may be comprised of inactive gases or vapors. The inactive gasses or vapors may fill the interior of the light sources and may have an inner wall coated with a material that fluoresces (e.g., a phosphorous material) when an electrical current passes through or near it. In the embodiment shown in  FIG. 4 , the plurality of lamps have a substantially cylindrical shape that couple a plurality of lamp holders  162  at side edges. In all uses, herein, the term substantially, includes an exact shape or dimension as well as shapes and dimensions near that which is described that do not appreciably affect the element or its function. The term couple or coupled, in all uses, herein, is intended to encompass both direct and indirect coupling. Thus, a lamp and a lamp holder are said to be coupled together when they are in direct contact, as well as when the lamp couples an intermediate part which couples the lamp holder directly or via one or more additional parts.  
         [0029]     A bottom cover  114  is positioned behind the plurality of lamps  160  arranged behind the plurality of lamps  162  and lamp holders  160  on a lowermost layer of the support main  124 . In this embodiment, side edges of the bottom cover  114  have an inclined face configured to reflect light from edge areas of the bottom cover  114  to the upper surfaces of the liquid crystal display panel  106 . A reflecting sheet  164  reflects light from the plurality of lamps  160  back toward the upper surfaces of the liquid crystal display panel  106 . The reflecting sheet  164  increases the amount of light that is incident to the liquid crystal display panel  106  while minimizing the light lost through the bottom cover  114 .  
         [0030]     A diffuser  166  that collects and spreads light across the optical sheets  168  is positioned above the plurality of lamps  160 . The diffuser  106  may comprise, for example, a light-diffusing material coated onto one or more sides of a film, which may be a transparent resin or an acrylic. A plurality of optical sheets  168  disposed between the diffuser  166  and the liquid crystal display panel  106  collects light exiting the diffuser  166  and adjusts the direction of the light such that light exits from the optical sheets  168  in a substantially perpendicular direction to a surface of the liquid crystal display panel  106 . The optical sheets improve the efficiency of the light impinging on the liquid crystal display panel  106 .  
         [0031]     In  FIG. 4 , the liquid crystal display panel  106  is comprised of an upper substrate  105  and a lower substrate  103  separated by a spacer (not shown). A liquid compound (not shown) or liquid crystal layer (not shown) having a polar molecular structure is positioned between the upper and the lower substrates  103  and  105  that polarize the light passing through it when an electric field is applied. A multi-color filter (not shown) may be disposed on the upper substrate  105  of the liquid crystal display panel  106  to generate color. The multi-color filter may include a black matrix, films containing three primary colors, dyes or pigments, and other components.  
         [0032]     In the embodiment shown in  FIG. 4 , data lines, gate lines, and other components (not shown) may be disposed on the lower substrate  103 . A thin film switch, such as a thin film transistor (TFT) in electrical contact with a data line and a gate line may form one of many liquid crystal cells that comprise the liquid crystal display panel  106 . The switches or TFTs pass data signals to the liquid crystal cell when biased by a scanning pulse (e.g., a gate pulse). A pixel electrode may be formed at a pixel area between a data line a gate line.  
         [0033]     In some embodiments, a side surface of the lower substrate  103  supports data and gate pads. A plurality of data tape carrier packages (TCP&#39;s)  108  electrically couple a data drive integrated circuit  110  through the data lines and data pads. A plurality of gate TCP&#39;s  104  electrically couple a gate drive integrated circuit  112  through gate lines and gate pads. In these embodiments, the data tape carrier packages (TCP&#39;s)  108  may be distributed across two or more circuit boards as shown in  FIG. 5 .  
         [0034]     As  FIG. 5  illustrates, two insulated boards or printed circuit boards (PCB) such as a first and a second circuit board  120  and  122  interconnect the plurality of data TCPs  108 . Although the embodiment encompasses any circuit layout and/or distribution,  FIG. 3  illustrates half of the data TCPs  108  interconnected on the first circuit board  120  and half of the data TCPs  108  interconnected on a second circuit board  122 . An adhesive secures the gate circuit board  126  to the bottom cover  114 . The adhesive may comprise a single or double-face tape, a resin, or other materials that tend to adhere to a surface.  
         [0035]     In  FIG. 5 , the first and second circuit boards  120  and  122  are isometric and are formed generally like a rectangle. A step-like cut out portion forms a protruding edge or first extending part  135  that is proximate to an almost equally dimensioned second protruding edge or second extending part  137 . A pair of openings or first and second apertures  134  and  136  are spaced apart from the respective first and second extending parts  135  and  137  away from the data TCPs  108 .  
         [0036]     As shown in  FIG. 5 , a side edge of the first extending part  135  lies near a side edge of the second extending part  137 . During assembly, the first and second data circuit boards  120  and  122  and the gate circuit boards  126  are folded toward a lower surface of the support main  124  as shown in  FIG. 6 . In this embodiment, a shield is disposed between the bottom cover  114  and the first, second, and gate circuit boards  120 ,  122 , and  126 . The shield, which may comprise any material that is a poor conductor of electricity, may be fastened to the bottom cover  114  by a fastener such as a screw.  
         [0037]     As shown in  FIG. 7 , a clip  130  includes a bottom plate  148  and a side wall  140 . The bottom plate  148  lies in a plane that is substantially perpendicular to the plane of the side wall  140 . A top plate  146  that is formed in a plane which is substantially parallel with and across from the plane of the bottom plane  148  is substantially perpendicular to the plane of the side wall  140 . In embodiment of  FIG. 7 , the side wall  140  is equal to or greater in length than widths of the first and/or second circuit boards  120  and  122 , but may be shorter in length than the lengths of top and/or bottom plates  146  and  148  of the clip  130 . Moreover, the length of the top plate  146  may be substantially equal to or shorter in length than the length of the bottom plate  148 .  
         [0038]     The bottom plate may further include protrusions that extend away from the plane of the bottom plate  146 . The protrusions may take any shape such the first and second spherical protrusions  152  and  154  shown in  FIG. 7  and may project away from the bottom plate  148  toward the top plate  146 . Moreover, although a plane of symmetry (not shown) may divide the spherical protrusions  152  and  154  shown in  FIG. 7 , the protrusions may be spaced apart in many other configurations. The clip  130  may be formed from any conducting material such as a metal or a combination of conducting and non-conducting materials and may take any shape like the substantially “U” shape shown in  FIG. 7 .  
         [0039]     As further shown in  FIG. 7 , the clip  130  also includes a first and a second flange or bending part  142  and  144 . The slope of the first bending part  142  descends from the ascending slope of the of the bottom plate  148 . The slope of the second bending part  144  ascends from the descending slope of the top plate  146 . These slopes of the bending parts  142  and  144  are configured to receive a width of the first and second circuit boards  120  and  122 . When a liquid crystal display embodiment is assembled, the first bending part  142  is in contact with an upper side surface of the first and second printed circuit boards  120  and  122 , while the second bending part  144  is in contact. with the rear side surface of the bottom cover  114 . The first spherical protrusion  152  may then be received into the first aperture  134  while the second spherical protrusion  154  may be received into the second aperture  136  as shown in  FIG. 8 . The engagement of the spherical protrusions  152  and  154  and apertures  134  and  136  may be dimensioned to resist some relative motion while allowing for the expansion and contraction of the first and second circuit boards  152  and  154  that may occur during use.  
         [0040]     When fully assembled, the clip  130  grips and holds the first and second extending parts  135  and  137  of the respective first and second printed circuit boards  120  and  122  which are grounded to the bottom cover  114  by contact. In one embodiment, the first and second printed circuit boards  120  and  122  are inserted between the top and bottom plates  146  and  148  of the clip  130 , respectively, until the first and second spherical protrusions  152  and  154  formed on the bottom plate  148  are received by the first and second openings or apertures  134  and  136  shown in  FIG. 5 . The clip  130  may act like a friction grip that may resist some relative motions caused by an external force while allowing for board expansion or contraction that may occur during the display&#39;s use. The clip  130  also maintains a common ground or ground potential between the first and second circuit boards  120  and  122  and the ground plane which may include the bottom cover  114 .  
         [0041]     To assemble an embodiment of a liquid crystal display, the bottom cover  114  is positioned between the reflecting sheet  164  and the support main  124  at act  902  of  FIG. 9 . The reflecting sheet  164  reflects light from an electroluminescent display or a plurality of lamps  160  that is disposed between a diffuser  166  and the reflecting sheet  164  at act  904 . The reflecting sheet  164  may increase the amount of light that is incident to the liquid crystal display panel  106  while minimizing the light lost through the bottom cover  114 . A diffuser  166  is positioned between one or more optical sheets  168  and the electroluminescent display or a plurality of lamps  160  at act  906 . The optical, sheets  168  collect and/or direct light toward the liquid crystal display panel  106 .  
         [0042]     During assembly, portions of the first and second printed circuit boards  120  and  122  that form part of the liquid crystal display panel  106  are inserted between the top and bottom plates  146  and  148  of the clip  130 , respectively at act  908 . A coupling force biases the clip  106  until the first and second spherical protrusions  152  and  154  formed on the bottom plate  148  of the clip  106  are received by the first and second openings or apertures  134  and  136  formed in the first and second circuit boards  120  and  122 . The clip  130  may act like a friction grip that may resist some relative motions caused by external forces while allowing for board expansion or contraction that may occur during the display&#39;s use. The first and second data circuit boards  120  and  122  and the gate circuit boards  126  are then folded toward a lower surface of the support main  124  allowing the clip  130  to couple a common ground plane that may be linked to the bottom cover  114  by a direct contact at act  910 . At act  910 , a shield may also be positioned between the bottom cover  114  and the first, second, and gate circuit boards  120 , 122 , and  126 . At act  912 , the case top  102  is positioned to partially enclose the support main  124  and the liquid crystal display panel  106 .  
         [0043]     The invention is not limited to the particular circuit board shapes or clip mechanisms described above. Any elastic or inelastic shape and suitable thread-less fastening device may be used to fasten and/or ground the circuit boards together. For example, the protrusions formed on the clip  130  may be integrally formed with or separately formed and attached or functionally attached to the circuit boards. In these embodiments, the circuit boards may not have the apertures such as those that may be formed in a first and a second extending part. Furthermore, some clips may not use protruding elements to grip and hold the boards together. In some of these alternative embodiments, a friction fit may be sufficient to hold or couple the boards together and link the boards to ground with or without the apertures. In some other alternative embodiments a clip may engage or couple at least top and bottom surfaces of at least a first and a second circuit board. In another alternative embodiment, one or more thin films may supply data and/or gate pulses to the liquid crystal display. In these embodiments, a clip would grip the films and provide a conducting path to ground.  
         [0044]     In the liquid crystal display embodiments described above, a thread-less fastening member may improve the assembly and operation of the display. In some of these embodiments, an elastic clip secures a first and second data circuit boards, which may comprise printed data circuit boards, to a grounded surface. In these embodiments, the liquid crystal display may be easily assembled by simply aligning the edges of multiple circuit boards and then sliding a clip across the extending parts of those boards. By this simple sliding of a clip across a portion of the multiple circuit boards, the assembly process is simplified, which lowers assembly time and increases assembly efficiency. The fastening device may also improve the operation of the display by increasing the conducting path to ground while also improving the display&#39;s mechanical durability by increasing the surface area that joins and holds the circuit boards or circuits together.  
         [0045]     While various embodiments of the invention have been described above, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible and within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the claims and their equivalents.