Abstract:
A backlight unit with socket connecter includes: a bottom frame having a topside and a backside; at least one lamp on the topside of the bottom frame; a socket connector disposed on a backside of the bottom frame, the socket connector being connected to the lamp; and a backlight circuit board having a plug connector connected to the socket connector.

Description:
This patent document claims the benefit of Korean Patent Application No. 10-2006-0060766, filed in Korea on Jun. 30, 2006, which is hereby incorporated by reference in its entirety. 
     BACKGROUND 
     1. Field 
     The present invention relates to a backlight unit and a backlight driving circuit board, and a liquid crystal display (LCD) module using the backlight unit. 
     2. Related Art 
     Flat panel display (FPD) devices have a relatively light weight, thin profile, and low power consumption. FPD devices are commonly used as a substitute for cathode ray tube (CRT) devices. Generally, display devices may be classified according to self-emission. For example, display devices may be classified as emissive display devices or non-emissive display devices. Emissive display devices display images by self-emitting light. Non-emissive display devices require a light source since they do not emit light by themselves. For example, plasma display panel (PDP) devices, field emission display (FED) devices, and electroluminescent display (ELD) devices are commonly used emissive display devices. Liquid crystal display (LCD) devices may be categorized as non-emissive display devices. However, some applications of LCD devices do not require a light source. LCD devices are commonly used in notebook and desktop computers because of their high resolution, color display capability, and high quality image. 
     LCD devices include an LCD module. The LCD module includes an LCD panel that displays images to an exterior and a backlight unit that supplies light to the LCD panel. The LCD panel includes two substrates that face each other and are spaced apart from each other. A liquid crystal material is interposed therebetween. Liquid crystal molecules of the liquid crystal material have a dielectric constant and refractive index anisotropic characteristics due to their long thin shape. Two electric field generating electrodes are formed on the two substrates, respectively. An orientation alignment of the liquid crystal molecules may be controlled by supplying a voltage to the two electrodes such that transmittance of the LCD panel is changed according to polarization properties of the liquid crystal material. 
     Generally, an additional light source is required because the LCD panel is a non-emissive-type display device. Accordingly, a backlight unit is disposed under the LCD panel. The LCD device displays images using light produced by the backlight unit and supplied to the LCD panel. Backlight units may be classified into a side-type backlight unit and a direct-type backlight unit in accordance with a disposition of the light source. The direct-type backlight unit has one lamp or a couple of lamps disposed at a side portion of a light guide plate. Alternatively, at least one lamp is disposed at each side portion of the light guide plate, respectively. 
     The side-type backlight unit has a plurality of lamps disposed under the light guide plate. In a large sized LCD module, the direct-type backlight unit may provide the LCD module with a uniform light source although the side-type backlight unit is more easily manufactured than the direct-type. 
       FIG. 1  is a schematic perspective view showing a direct-type backlight unit according to the related art. As shown in  FIG. 1 , a direct-type backlight unit includes a bottom frame  50 , a reflective sheet  22  on the bottom frame  50 , and a plurality of fluorescent lamps  24  on the reflective sheet  22 . Both sides of the bottom frame  50  are bent toward an inner portion thereof. Although not shown, the reflective sheet  22  has a plurality of holes corresponding to the plurality of fluorescent lamps  24 , so the light from the fluorescent lamp  24  is substantially exposed through the hole. For example, the reflective sheet  22  covers an inner surface of the bottom frame  50  except for the area where the fluorescent lamps  24  are disposed. Although not shown, a diffusion plate and an optical sheet group may be disposed on the fluorescent lamp. 
     As shown in  FIG. 1 , the fluorescent lamps are arranged parallel to each other and are driven by a high-low type that has a ground portion formed at respective end portions of the fluorescent lamps  24 . Light from the fluorescent lamp  24  is emitted by applying an alternating current voltage waveform through a wire  36  that extends from an electrode (not show) in the fluorescent lamp  24 . 
     As shown in  FIG. 1 , the fluorescent lamp  24  includes at least two fluorescent lamps. The couple of fluorescent lamps are fixed on the bottom frame  50  with a lamp holder  32  connected with the wire  35  that is connected to an external power supply. The wire  36  extends from a backside of the bottom frame  50  and is connected to a socket connector  38   a  at an end portion of the wire  36 . 
     An inverter  40  that converts a direct current voltage into an alternating current voltage is necessary because the alternating current voltage is required to drive the fluorescent lamp  24 . A backlight driving circuit board  34 , which includes a driving circuit (not shown) of the fluorescent lamp  24  and the inverter  40 , is mounted on the backside of the bottom frame  50 . The backlight driving circuit  34  further includes a plug connector  38   b  that connects the socket connector  38   a  and the backlight driving circuit  34 . A power supply is applied to the fluorescent lamp  24  through connecting the socket connector  38   a  and the plug connector  38   b.    
     The wire  36  is exposed at the backside of the bottom frame  50 , as shown in  FIG. 2 , for example, when the backlight driving circuit board  34  is mounted on the backside of the bottom frame  50  and when the socket connector  38   a , which is connected to the end portion of the wire  36  that extends from the fluorescent lamp  24 , is connected to the plug connector  38   b  on the backlight driving circuit board  34 . 
     Accordingly, the exposed wires  36  may contact each other, which would create a short or interference between the wires  36  and leakage of the voltage may occur by the alternating current voltage applied to the respective wires  36 . Consequently, there is a problem that the emission of the fluorescent lamp  24  is not uniform. 
     SUMMARY 
     The present embodiments may obviate one or more of the limitations or disadvantages of the related art. For example, in one embodiment, a backlight unit prevents interference between wires and leakage of the voltage. In another exemplary embodiment, a backlight unit includes fluorescent lamps capable of uniformly emitting light. 
     In one embodiment, a backlight unit includes a bottom frame that has a topside and a backside. At least one fluorescent lamp is disposed on a topside of the bottom frame. A socket connector is disposed on the backside of the bottom frame. The socket connector is connected to the fluorescent lamp. A backlight circuit board that has a plug connector is connected to the socket connector. 
     In one embodiment, a liquid crystal display module includes a backlight unit that has a topside and a backside and a bottom frame. At least one fluorescent lamp is disposed on a topside of the bottom frame. A socket connector is disposed on a backside of the bottom frame. The socket connector is connected to the fluorescent lamp. A backlight circuit board that has a plug connector is connected to the socket connector. A liquid crystal panel is disposed over the backlight unit. A main frame surrounds the liquid crystal panel and the backlight unit. A top frame surrounds a front edge of the liquid crystal panel. 
     In one embodiment, a method of connecting a backlight to a circuit board includes providing a through hole through a bottom frame, inserting a socket connector into the through hole, providing a plug connector on a backlight driving circuit board, and inserting the socket connector into the plug connector. 
     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 claimed subject matter, but is not intended to limit it. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a direct-type backlight unit according to the related art. 
         FIG. 2  is a schematic plan view showing a backside of a backlight unit of  FIG. 1 . 
         FIG. 3  is a perspective view showing one embodiment of an LCD module. 
         FIG. 4A  is a perspective view of one embodiment of a backlight unit for an LCD module, 
         FIG. 4B  is a cross-sectional view of one embodiment of a backlight unit for an LCD module. 
         FIG. 5  is a schematic plan view of one embodiment of a backside structure of a backlight unit. 
     
    
    
     DETAILED DESCRIPTION 
     In one embodiment, as shown in  FIGS. 3 ,  4 A and  4 B, an LCD module includes a LCD panel  110 , a backlight unit  120 , a main frame  130 , a bottom frame  150  and a top frame  140 . The backlight unit includes a reflective sheet  122 . A plurality of fluorescent lamps  124  are disposed on the reflective sheet  122  and arranged to be parallel to each other. An optical sheet group  126  is disposed on the fluorescent lamps  124 . Each of the fluorescent lamps  124  is fixed by a plurality of side supports  128  on the bottom frame  150 . However, the present embodiments are not limited to a plurality of side supports  128 . For example, one side support may be used to fix one fluorescent lamp or a plurality of fluorescent lamps. 
     In one embodiment, an LCD panel  110  is disposed over the backlight unit  120 . The backlight unit  120  and the LCD panel  110  are fixed as a set by the bottom frame  150  that surrounds the backlight unit  120  and the top frame  140  combined with the bottom frame  150 . In this embodiment, the backlight unit  120  includes a backlight driving circuit board  134  that includes a driving circuit. 
     In one embodiment, a gate printed circuit board  118  and a source printed circuit board  119  are disposed along edges of the LCD panel  110  using a flexible circuit board  116 . The gate printed circuit board  118  and the source printed circuit board  119  are bent and adhered toward or to a side or a backside of the bottom frame  150  during a modulation process of the backlight unit  120 . The gate printed circuit board  118  applies an ON/OFF signal of a thin film transistor (not shown) through a plurality of gate lines (not shown), and the source printed circuit board  119  applies an image signal by one frame through a plurality of data lines (not shown). For example, the gate printed circuit board  118  and the source printed circuit board  119  are disposed adjacent to each other. 
     In one embodiment, the backlight unit  120  includes the backlight driving circuit board  134  on which the driving circuit that controls the plurality of fluorescent lamps  124  is mounted. As shown in  FIG. 4A , the socket connector  138   a  is inserted into a through hole (not shown) of the bottom frame  150  to connect the fluorescent lamp  124  and the wire  136 . The wire  136  is connected to the socket connector  138   a  and connected to an external power supply of the fluorescent lamp  124 . The plug connector  138   b  on the backlight driving circuit board  134  that is mounted on the backside of the bottom frame  150  is connected to the socket connector  138   a.    
     As shown in  FIG. 4A , the reflective sheet  122  is disposed on the bottom frame  150 , and the plurality of fluorescent lamp  124  are disposed on the reflective sheet  122  and are arranged to be parallel to each other. For example, both edge portions of the bottom frame  150  are bent along a top direction toward the LCD panel (not shown), and the fluorescent lamps  124  are disposed on the reflective sheet  122 . The reflective sheet  122  has a plurality of holes (not shown) corresponding to the fluorescent lamps  124 , so the fluorescent lamps  124  are exposed through the holes. The reflective sheet  122  is disposed on the inner surface of the bottom frame  150  except the fluorescent lamps  124 . 
     In one embodiment, the fluorescent lamp  124  includes a glass tube (not shown), a discharge gas in the glass tube, and a fluorescent substance (not shown) on an inner surface of the glass tube. Electrodes (not shown) may be formed at both end portions of the glass tube. In one embodiment, the fluorescent lamp  124  includes at least a couple of fluorescent lamps  124  and is fixed on the bottom frame  150  through the lamp holder  132  connected to the wire  136  that is connected to the external power supply. The fluorescent lamp  124  is connected to the wire  136  at the end portion thereof. A through hole (not shown) is formed in the bottom frame  150  so that the socket connector  138   a  is inserted into the through hole of the bottom frame  150 . The socket connector  138   a , which is connected to the end portion of the wire  136 , is exposed in the backside of the bottom frame  150  and is fixed from the bottom frame  150 . 
     In one embodiment, the fluorescent lamp  124  is a high-low type that has a ground portion formed at the end portion of the fluorescent lamp  124 . An inverter that changes the direct current voltage into an alternating current voltage because the alternating current voltage is necessary for driving the highlow type fluorescent lamp  124 . For example, the alternating current voltage is a high voltage. The backlight driving circuit board  134  on which the driving circuit and the inverter are mounted is disposed on the backside of the bottom frame  150 . 
     A plurality of plug connectors  138   b  are projected toward the socket connector  138   a  and disposed on the backlight driving circuit board  134 . 
     In one embodiment, as shown in  FIG. 4B , the socket connector  138   a  is inserted into the through hole of the bottom frame  150  and is fixed to the bottom frame  150 . The socket connector  138   a  is exposed from the backside of the bottom frame  150 , and the plug connector  138   b  is disposed on the backlight driving circuit board  134  toward the socket connector  138   a . The socket connector  138   a  is inserted into the plug connector  138   b , so the fluorescent lamp  124  and the backlight driving circuit board  134  are electrically connected to each other. The power supply of the alternating current voltage applies to the electrodes and the fluorescent lamp  124  is emitted by connecting the socket connector  138   a  and the plug connector  138   b . For example, the alternating current voltage is a high voltage. 
       FIG. 5  is a schematic plan view of a backside structure of a backlight unit of  FIG. 4 . In  FIG. 5 , the fluorescent lamp  124  and the backlight driving circuit board  134  are electrically connected to each other by connecting the socket connector  138   a  and the plug connector  138   b  in order to prevent exposure of the wire  136  ( FIG. 4A ). 
     For example, the wires  136  according to the related art extend from the backside of the bottom frame with an exposed state and create interference of the wires and leakage of the voltage. 
     In one embodiment, the socket connector, which is inserted into the bottom frame and exposed from the backside of the bottom frame, is combined with the plug connector on the backlight driving circuit board in order to connect the fluorescent lamp and the backlight driving circuit board. As explained above, since the fluorescent lamp and the backlight driving circuit board are electrically connected using the socket connector and the plug connector, interference between wires or the leakage of the voltage can be prevented. Consequently, the fluorescent lamp can be uniformly emitted. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in a liquid crystal display device of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.