Abstract:
A liquid crystal display module, includes: a light guide plate having a side surface, a rear surface and a top surface opposite to the rear surface; a reflective sheet having a front side on the rear surface of the light guide plate for reflecting light into the light guide plate and also having a rear side opposite to the front side; a lead connected to a light emitting diode lamp adjacent to the light guide plate; and a bottom frame surrounding the side surface of the light guide plate and covering edges of a rear surface of the light guide plate such that a center of the rear side of the reflective sheet is exposed in an opening of the bottom frame, wherein the lead passes through the opening in the bottom frame such that an end of the lead is disposed outside of the bottom frame.

Description:
The present invention claims the benefit of Korean Patent Application No. 10-2008-0066400 filed in Korea on Jul. 9, 2008, which is hereby incorporated by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a liquid crystal display (LCD) device, and more particularly, to a liquid crystal display module (LCDM) having a simple structure. 
     2. Discussion of the Related Art 
     The liquid crystal display module (LCDM) is widely used as a display device for a notebook personal computer (NTPC). The LCDM includes a liquid crystal panel and a driving circuit unit for driving the liquid crystal panel. The liquid crystal panel includes a first substrate and a second substrate and a layer liquid crystal material interposed therebetween. The liquid crystal material is divided into cells arranged in a matrix. Switching elements for controlling signals applied to the liquid crystal cells are formed on one of the first and second substrates. 
     The liquid crystal panel does not have a light source therein. Thus, the LCDM requires a light source that projects light into the liquid crystal panel. The light source for the LCDM can be a backlight unit that includes a lamp. 
       FIG. 1  is a cross-sectional view of the related art LCDM. As shown in  FIG. 1 , the LCDM includes a liquid crystal panel  1 , a main frame  5 , a top frame  12 , and a bottom frame  14 . The liquid crystal panel  1  includes first and second substrates (not shown) facing each other with a layer of liquid crystal material (not shown) therebetween. First and second polarization plates  42  and  44  are attached onto outer surfaces of the first and second substrates, respectively. A switching element, such as a thin film transistor (TFT), is formed on the first substrate. The top frame  12  covers edges of the liquid crystal panel  1  and sides of the main frame  5  such that the top frame  12  can support and protect the edges of the liquid crystal panel  1  and the sides of the main frame  5 . The main frame  5  is combined with the top frame  12  by an affixing element, such as a screw. 
     Generally, the main frame  5  is fabricated using a mold. However, to provide television or monitor with high brightness, the main frame  5  is formed of a metallic material, such as aluminum (Al), having an excellent heat resistant property. The liquid crystal panel  1  is disposed on the main frame  5 . The bottom frame  14  covers back edges of the main frame  5 , so that the bottom frame  14  is combined with the main frame  5 , the top frame  12  and a backlight unit to form a module. 
     A backlight unit of the LCDM includes a light emitting diode (LED) lamp  32  as a light source, a light guide plate  34  that disperses the dot light source of the LED lamp  32  into planar light, a reflective sheet  36  disposed under the light guide plate  34  and an optical sheet, including a prism sheet  24  and a diffusion sheet  22 , stacked on the light guide plate  34 . The LED lamp  32  is disposed at a side of the light guide plate  34 . The light from the LED lamp  32  is projected into the side of the light guide plate  34  and reflected by the reflective sheet  36  to be changed into planar light. Then, the planar light is projected into the liquid crystal panel  1 . The backlight unit may further include a lamp housing (not shown) surrounding the LED lamp  32  to increase a light efficiency. The lamp housing is formed of a material having a high optical reflectance. 
     The light guide plate  34  having a predetermined thickness includes an inclined rear surface and a flat front surface. The reflective sheet  36  reflects the light provided thereon from the rear surface of the light guide plate  34  back into the light guide plate  34  such that light projects from the front surface. As a result, light loss is reduced due to the reflective sheet  36 . 
       FIG. 2  is a perspective view of the related art LED lamp array.  FIG. 3  is a perspective view showing a rear side of the related art LCDM. Referring to  FIGS. 2 and 3  with  FIG. 1 , a plurality of LED lamps  32  are arranged on a flexible printed circuit board (FPCB)  31 . The FPCB  31  with the LED lamps can be referred to as the LED lamp array  30 . The FPCB  31  is located on an inner side surface of the bottom frame  14  and extends onto an outer side by passing through a hole H in the side surface of the bottom frame  14 . An exterior circuit connection part  33  is formed at an end of the FPCB  31 . More specifically, the exterior circuit connection part  33  passes through the hole H and is connected to an exterior circuit connection part  33 , such as a backlight unit controlling circuit (not shown), for applying control signal or operating power to the LEDs  32 . 
     Unfortunately, when a position of the exterior circuit connection part  33  in the LED lamp array  30  is changed, a position of the hole H also has to be changed. However, since changes to the mold for fabricating the bottom frame  14  is required for changes in the position of the exterior circuit connection part  33 , production costs increase. Moreover, production time increases when such changes are implemented. 
     SUMMARY OF THE INVENTION 
     Accordingly, embodiments of the invention are directed to an LCDM that substantially obviates one or more of the problems due to limitations and disadvantages of the related art. 
     Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and-broadly described, a liquid crystal display module, includes: a light guide plate having a side surface, a rear surface and a top surface opposite to the rear surface; a reflective sheet having a front side on the rear surface of the light guide plate for reflecting light into the light guide plate and also having a rear side opposite to the front side; a lead connected to a light emitting diode lamp adjacent to the light guide plate; and a bottom frame surrounding the side surface of the light guide plate and covering edges of a rear surface of the light guide plate such that a center of the rear side of the reflective sheet is exposed in an opening of the bottom frame, wherein the lead passes through the opening in the bottom frame such that an end of the lead is disposed outside of the bottom frame. 
     In another aspect, a liquid crystal display module includes: a liquid crystal panel; a main frame surrounding the liquid crystal panel; a top frame covering the liquid crystal panel and the main frame; a light guide plate having a side surface, a rear surface and a top surface opposite to the rear surface; a bottom frame covering the main frame; and a lead connected to a light emitting diode lamp that is adjacent to the bottom frame, wherein the lead passes between the light guide plate and the bottom frame such that the lead is disposed outside of the bottom frame. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
         FIG. 1  is a cross-sectional view of the related art LCDM. 
         FIG. 2  is a perspective view of the related art LED lamp array. 
         FIG. 3  is a perspective view showing a rear side of the related art LCDM. 
         FIG. 4   a  is a cross-sectional view of an LCDM according to an embodiment of the invention having a flexible lead integrated with the flexible printed circuit board on which a top emitting diode is mounted. 
         FIG. 4   b  is a cross-sectional view of an LCDM according to an embodiment of the invention having a lead contacting the flexible printed circuit board on which a top emitting diode is mounted. 
         FIG. 5  is a perspective view showing a rear side of the LCDM shown in  FIG. 4   a.    
         FIG. 6   a  is a cross-sectional view of an LCDM according to an embodiment of the invention having a flexible lead integrated with the flexible printed circuit board on which a side emitting diode is mounted. 
         FIG. 6   b  is a cross-sectional view of an LCDM according to an embodiment of the invention having a lead contacting the flexible printed circuit board on which a side emitting diode is mounted. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Reference will now be made in detail to exemplary embodiments of the invention, which are illustrated in the accompanying drawings. Like element numbers in the figures denote similar elements amongst the embodiments. 
       FIG. 4   a  is a cross-sectional view of an LCDM according to an embodiment of the invention having a flexible lead integrated with the flexible printed circuit board on which a top emitting diode is mounted.  FIG. 4   b  is a cross-sectional view of an LCDM according to an embodiment of the invention having a lead contacting the flexible printed circuit board on which a top emitting diode is mounted. As shown in  FIG. 4   a , an LCDM includes a liquid crystal panel  101 , a main frame  105 , a top frame  112 , and a bottom frame  114 . The liquid crystal panel  101  includes first and second substrates (not shown) facing each other with a liquid crystal material (not shown) therebetween. First and second polarization plates  142  and  144  are attached onto outer surfaces of the first and second substrates, respectively. A switching element, such as a thin film transistor (TFT), is formed on the first substrate. 
     The main frame  105  surrounds sides of the liquid crystal panel  101 . The top frame  112  covers edges of the liquid crystal panel  101  and sides of the main frame  105  such that the top frame  112  can support and protect the edges of the liquid crystal panel  101  and sides of the main frame  105 . The main frame  105  is combined with the top frame  112  by an affixing element, such as a screw. 
     The main frame  105  is fabricated using a mold. To meet requirements for high brightness, the main frame  105  is formed of a metallic material, such as aluminum (Al), having an excellent heat resistant property. The liquid crystal panel  101  is disposed on the main frame  105 . The bottom frame  114  covers back edges of the main frame  105  so that the bottom frame  114  can be combined with the main frame  105 , the top frame  112  and a backlight unit into a module. 
     A backlight unit of the LCDM is disposed under the liquid crystal panel  101  and includes a light emitting diode (LED) lamp  132  as a light source, a light guide plate  134  that disperses the dot light source of the LED lamp  132  into a planar light source, a reflective sheet  136  disposed under the light guide plate  134  and an optical sheet, including a prism sheet  124  and a diffusion sheet  122 , stacked on the light guide plate  134 . The LED lamp  132  is disposed at a side of the light guide plate  134 . The light from the LED lamp  132  is projected into the side of the light guide plate  134  and reflected by the reflective sheet  136  to be changed into planar light. Then, the planar light is projected into the liquid crystal panel  10 . The backlight unit may further include a lamp housing (not shown) surrounding the LED lamp  132  to increase a light efficiency. The lamp housing is formed of a material having a high optical reflectance. 
     The light guide plate  134  having a predetermined thickness includes an inclined rear surface and a flat front surface. The reflective sheet  136  reflects the light provided thereon from the rear surface of the light guide plate  134  back into the light guide plate  134  such that light projects from the front surface. As a result, light loss is reduced due to the reflective sheet  136 . 
     The LED lamp  132  is disposed at the one end of the FPCB  131  such that the light emitted from the LED lamp  132  is provided directly into the light guide plate  134 . The LED lamp  132  includes first and second surfaces  132   a  and  132   b . The first surface  132   a  is substantially parallel to a side surface of the bottom frame  114  and has a first width, and the second surface  132   b  is substantially perpendicular to the side surface of the bottom frame  14  and the first surface  132   a  and has a second width smaller than the first width. Thus, the LED lamp  132  is mounted on a surface of the bottom frame  114  that is parallel to the side surface  134   a  of the light guide plate  134 . The light is emitted through the first surface  132   b  of the LED lamp  132 . Such an LED lamp  132  can also be referred to as a top emitting type LED. 
     An exterior circuit connection lead  133  is connected to the FPCB  131 . More particularly, the exterior circuit connection lead  133  FPCB  131  passes through the space between the light guide plate  134  and the bottom frame. Accordingly, the exterior circuit connection lead  133  can be connected to an external circuit, such as a backlight unit controlling circuit (not shown), for applying a control signal and operating power. 
       FIG. 4   a  shows the exterior circuit connection lead  133  and the FPCB  131  as one integrated body, the exterior circuit connection lead  133  can be a separate element from the FPCB  131 . As shown in  FIG. 4   b , the FPCB  151  contacts the exterior circuit connection lead  153 , which only provides wiring between the FPCB  131  and the external circuit. 
       FIG. 5  is a perspective view showing a rear side of the LCDM shown in  FIG. 4   a . Referring to  FIG. 5 , a flexible printed circuit board (FPCB)  131 , on which a plurality of LED lamps  132  are arranged, extends from an inner side of the bottom frame  114  outside of the bottom frame  114  by passing through a space between the light guide plate  134  and the bottom frame  114 . The FPCB  131 , where the LED  132  lamps are arranged, may be referred to as an LED lamp array. The bottom frame  114  surrounds a side surface of the light guide plate  134  and covers edges of a rear side of the light guide plate  134  such that a center of the rear side of the reflective sheet  136  is exposed. There is space between the light guide plate  134  and the bottom frame  114  at boundaries of the light guide plate  134  and the bottom frame  114 . One end of the FPCB  131  is located on an inner side surface of the bottom frame  114 , and the other end of the FPCB  131  passes through the space between the light guide plate  134  and the bottom frame  114 . More particularly, the FPCB  131  passes through the space between the light guide plate  134  and the bottom frame  114 . 
     When the reflective sheet  136  is disposed between the bottom frame  114  and the light guide plate  134 , the space, where the other end of the FPCB  131  passes, is disposed between the bottom frame  114  and the reflective sheet  136 . Since the FPCB  131  has a relatively small thickness, there is no increase in a total thickness of the LCDM due to the above structure. 
       FIG. 6   a  is a cross-sectional view of an LCDM according to an embodiment of the invention having a flexible lead integrated with the flexible printed circuit board on which a side emitting diode is mounted.  FIG. 6   b  is a cross-sectional view of an LCDM according to an embodiment of the invention having a lead contacting the flexible printed circuit board on which a side emitting diode is mounted. As shown in  FIG. 6   a , an LCDM includes a liquid crystal panel  201 , a main frame  205 , a top frame  212 , and a bottom frame  214 . The liquid crystal panel  201  includes first and second substrates (not shown) facing each other and a layer of liquid crystal material (not shown) therebetween. First and second polarization plates  242  and  244  are attached onto outer surfaces of the first and second substrates, respectively. A switching element, such as a thin film transistor (TFT), is formed on the first substrate. 
     The main frame  205  surrounds sides of the liquid crystal panel  201 . The top frame  212  covers edges of the liquid crystal panel  201  and sides of the main frame  205  such that the top frame  212  can support and protect of the edges of the liquid crystal panel  201  and sides of the main frame  205 . The main frame  205  is combined with the top frame  212  by an affixing element, such as a screw. 
     The main frame  205  is fabricated using a mold. To meet the requirement for a high brightness, the main frame  205  is formed of a metallic material, such as aluminum (Al), having an excellent heat resistance property. The liquid crystal panel  201  is disposed on the main frame  205 . The bottom frame  214  covers back edges of the main frame  205 , so the bottom frame  214  is combined with the main frame  205 , the top frame  212  and a backlight unit into a module. 
     A backlight unit of the LCDM is disposed under the liquid crystal panel  201  and includes a light emitting diode (LED) lamp  232  as a light source, a light guide plate  234  that disperses the dot light source from the LED lamp  232  into a planar light source, a reflective sheet  236  disposed under the light guide plate  234  and an optical sheet, including a prism sheet  224  and a diffusion sheet  222 , stacked on the light guide plate  234 . The LED lamp  232  is disposed at a side of the light guide plate  234 . The backlight unit may further include a lamp housing (not shown) surrounding the LED lamp  232  to increase a light efficiency. The lamp housing is formed of a material having a high optical reflectance. 
     The light from the LED lamp  232  is projected into the side of the light guide plate  234  and reflected by the reflective sheet  236  to be changed into planar light. Then, the planar light is projected into the liquid crystal panel  201 . The light guide plate  234  having a predetermined thickness includes an inclined rear surface and a flat front surface. The reflective sheet  236  reflects the light provided thereon from the rear surface of the light guide plate  234  back into the light guide plate  234  such that light projects from the front surface. As a result, light loss is reduced due to the reflective sheet  236 . 
     A flexible printed circuit board (FPCB)  231 , on which a plurality of LED lamps  232  are arranged, extends from an inner side of the bottom frame  214  outside of the bottom frame  214  by passing through a space between the light guide plate  234  and the bottom frame  214 . The FPCB  231 , where the LED lamps  232  are arranged, may be referred to as an LED lamp array. The bottom frame  214  surrounds a side surface of the light guide plate  234  and covers edges of a rear side of the light guide plate  234  such that a center of the rear side of the reflective sheet  236  is exposed. There is a space between the light guide plate  234  and the bottom frame  214  at boundaries of the light guide plate  234  and the bottom frame  214 . One end of the FPCB  231  is located on an inner bottom surface of the bottom frame  214 , and the other end of the FPCB  231  passes through the space between the light guide plate  234  and the bottom frame  214 . More particularly, the FPCB  231  passes through the space between the light guide plate  234  and the bottom frame  214 . 
     The LED lamp  232  is disposed at one end of the FPCB  231  such that the light emitted from the LED lamp  232  is provided directly into the light guide plate  234 . The LED lamp  232  includes first and second surfaces  232   a  and  232   b . The first surface  232   a  is substantially parallel to the bottom surface of the bottom frame  214  and has a first width, and the second surface  232   b  is substantially perpendicular to the bottom surface of the bottom frame  214  and the first surface  232   a  and has a second width smaller than the first width. Thus, the LED lamp  232  is mounted on a surface of the bottom frame  214  that is perpendicular to the side surface  234   a  of the light guide plate  234 . The light is emitted through the second surface  232   b  of the LED lamp  232 . Such an LED lamp  232  can be referred to as a side emitting type. 
     An exterior circuit connection lead  233  is formed at the other end of the FPCB  231 . The FPCB  231  is connected to an exterior circuit connection lead  233 , such as a backlight unit controlling circuit (not shown), for applying a control signal and an operating power. 
       FIG. 6   a  shows the exterior circuit connection lead  233  and the FPCB  231  as one integrated body, the exterior circuit connection lead  233  can be a separate element from the FPCB  231 . As shown in  FIG. 6   b , the FPCB  251  contacts the exterior circuit connection lead  153 , which only provides wiring between the FPCB  231  and the external circuit. 
     When the reflective sheet  236  is disposed between the bottom frame  214  and the light guide plate  234 , the space, where the other end of the FPCB  231  (or the exterior circuit connection lead  233 ) passes, is disposed between the bottom frame  214  and the reflective sheet  236 . Since the FPCB  231  has a relatively small thickness, there is no increase in an overall total thickness of the LCDM due to the above structure. 
     Since the FPCB (or the exterior circuit connection part) passes inside of the bottom frame through a space between the bottom frame and the reflective sheet (or the light guide plate) out of the bottom frame, the LCDM according to embodiments of invention do not require a hole in the bottom frame through which the FPCB passes, as shown in  FIG. 2 . Accordingly, the fabricating process for the bottom frame is simplified and there is no limitation on the position with respect to the bottom frame of where the FPCB comes out of the bottom frame. Moreover, since there is no hole in the bottom frame of the LCDM according to embodiments of the invention, problems resulting from particles entering through such a hole and light loss by such a hole are prevented. In addition, since a process of inserting an end of the FPCB into a hole at the bottom frame is no longer necessary, the assembling process of the LCDM in embodiments of the invention is simplified. It will be apparent to those skilled in the art that various modifications and variations can be made in the exemplary embodiments of the invention without departing from the spirit or scope of the invention. Thus, it is intended that the invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.