Abstract:
A lamp assembly includes a lamp housing for housing one or more predefined tubular lamps and at least a first lamp socket for coupling to and removably retaining respective first electrodes of the one or more lamps and for further coupling an integral conduction path of the lamp housing to at least one of the first electrodes.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application relies for priority upon Korean Patent Application No. 2006-76288 filed on Aug. 11, 2006, the disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     1. Field of Invention 
     The present disclosure of invention relates to a lamp assembly for use in a backlighted liquid crystal panel and more particularly to a lamp assembly having a structure that allows for manufacture with fewer parts, better alignability and reduced manufacturing cost. 
     2. Description of Related Art 
     A typical liquid crystal display (LCD) panel includes means for projecting an artificial light from behind the LCD array so as to better display a computer-generated or other pixel-based image using electrical characteristics and optical characteristics of a liquid crystal material included in the LCD array. 
     The typical LCD device includes a liquid crystal control unit that controls electrical signals applied to the liquid crystal material and it further includes a light-providing unit that provides light for illuminating the liquid crystal array even when used in darkness. For example, the typical LCD device includes an LCD panel assembly having the liquid crystal control unit, and a backlighting assembly serving as the light-providing unit of the LCD panel. 
     The backlighting assembly typically has a light source such as one or more fluorescent lamps inserted therein for generating light. Backlighting assemblies may be classified as being either of a direct illumination type of backlighting or as of an edge-illuminated type of backlighting depending on the position of the main light source. A typical edge-illumination type backlighting assembly includes a light guiding plate for disposition behind the LCD panel and a lighting source such as one or more fluorescent lamps or an array of light emitting diodes (LEDs) disposed at a side edge of the light guiding plate for directing light into the guiding plate. The guiding plate then guides the light through a back portion of the LCD array for projection of a resulting image towards the eyes of a user. 
     A typical edge-illumination type backlighting assembly includes a lamp assembly having at least one high voltage lamp of a thin and long cylindrical shape. The lamp is electrically connected to a high voltage generator (i.e., an inverter) through a set of power supply wires so as to receive electrical power from the generator/inverter and thereby generate light energy. 
     A conventional lamp assembly includes a lamp reflector, a lamp holder for receiving two or more cylindrical lamps, a set of power supply wires, a series-tapping return wire for returning a control signal to the power supply from a tap point provided along a series connection of lamps, a fixing tape for adhesively fixing the return wire to the assembly, a wire harness for harnessing the power supply and return wires, etc. The conventional lamp assembly is manually assembled as follows. The lamp holder is physically connected at solderable portions thereof to the power supply wires of the harness, and the power supply wires are then soldered to the lamp holder with the use of a hot soldering iron, solder flux and a spool of solder. Then, the so soldered lamp holder is closed so as to protectively house the soldered portion, and the lamp holder is thereafter mechanically coupled to the lamp reflector. Thereafter, the tap-point return wire is manually positioned into a groove formed on a rear surface of the lamp reflector, and the return wire is affixed to the assembly by using the fixing tape. 
     As described above, the conventional manufacture of the conventionally-structured lamp assembly includes the use of many parts, and many separate manual steps, each requiring good dexterity and each subject to something possibly going wrong during the manufacturing process. Additionally the tap-return wire of the conventional lamp assembly is routed to extend from a backside to another side of the lamp assembly and this presents an opportunity for the wire to be hooked and pulled off or something else to go wrong. Thus, the conventional lamp assembly has a structure that calls for a complex and manual assembly process in which a number of things can go wrong, thereby increasing manufacturing cost of the lamp assembly and making its manufacture less than fully reliable. 
     SUMMARY 
     The present disclosure of invention provides a lamp assembly having a structure that is easy and reliable to assemble and thus capable of enjoying reduced manufacturing costs. 
     In one embodiment, a lamp assembly includes an optically reflective and electrically conductive lamp housing and first and second lamp sockets that are structured for easy self-aligning fastening to the lamp housing, for automatic electrical coupling of at least the first socket to the housing and for simplified connection of a tap return wire to the first socket by way of a connection made through the body of the lamp housing. In one embodiment, each of a series connected plurality of fluorescent lighting lamps has a first external connection electrode and a second external connection electrode. The first and second external connection electrodes are used to supply electrical power to their respective lamps and to thus enable the lamps to generate light. The lamp housing receives and houses the lamp bodies. The first lamp socket is fastened to the lamp housing so as to be able to receive at least a first end portion of each of the lamps and to secure the lamps to the housing. The first lamp socket electrically connects the first electrodes of at least two lamps one to the other. The first socket also electrically connects the tap point defined by the lamp-to-lamp electrodes connection to an electrically-conductive first portion of the lamp housing. A tap return wire is connected to another part of the electrically-conductive portion of the lamp housing to thereby provide a coupling of the tap point to a control terminal of an associated power supply. 
     In one embodiment, the first lamp socket includes a socket body having a receiving space sized to receive end portions of two or more lamps and a set of electrode-receiving terminals disposed in the receiving space of the first socket body for receiving, retainably clamping to and electrically connecting to the first electrodes of the two or more lamps and for electrically interconnecting the first electrodes to one another and further to an electrically conductive portion of the lamp housing. 
     The first lamp socket may have an opening through which the at least two lamps extend outwardly, and the first lamp socket may further include a first cover for covering the lamps receiving space so as to impede the entry of dust, debris or other undesirable materials into the receiving space. The first cover may be hingedly-coupled to the first socket body or deformably bent into position to thereby enclose the lamps receiving space. 
     In one embodiment, the set of electrode-receiving terminals that are disposed in the receiving space of the first socket define first electrode fixing portions for mechanically fastening to (i.e., removably retaining) the first electrodes and electrically connecting to the first electrodes of the lamps inserted into the first socket. The set of electrode-receiving terminals further define a housing interconnect portion for mechanically attaching to and electrically connecting to the lamp housing, and a connection extension portion for electrically interconnecting the first electrode fixing portions with the housing interconnect portion. The first electrode fixing portions fix the positions of the corresponding lamps and support those lamps by way of their first electrodes. 
     In an exemplary embodiment, an interconnect throughhole is formed through a base portion of the first lamp socket, and the lamp housing includes a protruding contact terminal protruding from a base surface of the lamp housing for extending inwardly into the first lamp socket through the interconnect throughhole. The connection extension portion in the first socket may have a clip or clamp shape into which the protruding contact terminal of the lamp housing is inserted to thereby establish an electrical connection between the electrically conductive portion of the lamp housing and the connection extension portion in the first socket. In another exemplary embodiment, a throughhole is formed at the bottom of the first lamp socket, and the housing connecting portion outwardly extends from the first lamp socket through the throughhole to electrically connect to an inner surface of the lamp housing. In still another exemplary embodiment, a throughhole is formed at the first lamp socket, and the housing connecting portion is formed on both inner and outer surfaces of the first lamp socket that are adjacent to the throughhole and a portion of the first lamp socket that connects the inner and outer surfaces through the throughhole defines the electrical connection of the extension portion to the inner surface of the lamp housing. 
     In one embodiment, at least two lamps may be received side-by-side in the lamp housing, and the first lamp socket may further include an insulating rib protruding from an inner surface of the first lamp socket and extending to be disposed between the first electrodes of the lamps to thereby dielectrically separate the two lamps. 
     The lamp assembly may optionally further include a second lamp socket that is disposed at another end of the lamp housing to receive opposed end portions of the two or more lamps and further secure the lamps to the lamp housing. The second lamp socket electrically connects respective second electrodes of the two or more lamps to corresponding power supply wires provided for applying ignition and plasma sustaining voltages the respective lamps. 
     The second lamp socket may include a socket body having a receiving space for receiving corresponding end portions of the lamps and second electrode-receiving terminals disposed in the receiving space of the second socket body for electrically connecting to the second electrodes of the lamps and coupling those second electrodes to the power supply wires. The second lamp socket may have an opening through which the corresponding end portions of the lamps are received into the second lamp socket, and the second lamp socket may further include a second cover for covering the opening to block dirt and debris from entering the lamp receiving space. In one embodiment, the second cover is hingedly-coupled to the second socket body. The second electrode-receiving terminals include, for example, respective second electrode fixing portions for mechanically fastening to and electrically connecting to the second electrodes of the lamps and wire connecting portions for electrically connected to respective power supply wires. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features relating to the present disclosure of invention will become clearer when studied in view of the detailed exemplary embodiments disclosed below with reference to the accompanying drawings, in which: 
         FIG. 1  is an exploded perspective view illustrating a lamp assembly according to a first exemplary embodiment; 
         FIG. 2  is an enlarged perspective view of the first lamp socket of the lamp assembly illustrated in  FIG. 1 ; 
         FIG. 3  is a plan view of the first lamp socket of the lamp assembly illustrated in  FIG. 2 ; 
         FIG. 4  is a partial cross-sectional view taken along a line I-I′ in  FIG. 2 ; 
         FIG. 5  is an enlarged perspective view of the second lamp socket of the lamp assembly illustrated in  FIG. 1 ; 
         FIG. 6  is a plan view of the second lamp socket of the lamp assembly illustrated in  FIG. 5 ; 
         FIG. 7  is a partial cross-sectional view taken along a line II-II′ in  FIG. 5 ; 
         FIGS. 8A and 8B  are partial perspective views illustrating an exemplary embodiment of the connection between a tap terminal and a tap connection portion of the lamp assembly illustrated in  FIG. 1 ; 
         FIGS. 9A and 9B  are partial perspective views illustrating another exemplary embodiment of the connection between a tap terminal and a tap connection portion of the lamp assembly illustrated in  FIG. 1 ; 
         FIGS. 10A and 10B  are cross-sectional views illustrating a first lamp socket of a lamp assembly according to another exemplary embodiment; 
         FIGS. 11A and 11B  are cross-sectional views illustrating a first lamp socket of a lamp assembly according to still another exemplary embodiment; 
         FIG. 12  is an exploded perspective view illustrating a backlighting assembly according to an exemplary embodiment; and 
         FIG. 13  is an exploded perspective view illustrating a liquid crystal display device according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The below detailed descriptions, including the accompanying drawings, provide examples of embodiments in accordance with the present disclosure of invention. The inventive subject matter may, however, be embodied in many different forms and variations and should not be construed as being limited to the exemplary embodiments set forth herein. A variety of different materials may be used to provide the described functions including electrically conductive metals, optically reflective materials, and/or electrically insulating plastics or ceramics. It will be understood that when an element is referred to herein as being “on” or “onto” or “coupled” to another element, it may be directly disposed on or attached to the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” or “directly coupled to” another element, then no intervening elements may be present. Like reference numerals generally refer to similar or identical elements throughout. 
       FIG. 1  is an exploded perspective view illustrating a lamp assembly  100  in accordance with the present disclosure. 
     Referring to  FIG. 1 , the lamp assembly  100  optionally includes a supplied set  110  of fluorescent lamps, and the assembly  100  includes an electrically-conductive lamp housing  120  (i.e., one having an optically reflective and electrically conductive inner surface made of polished aluminum for example). The lamp assembly  100  further includes, a first lamp socket  130  structured for fastening and electrical connection to a left end portion of the lamp housing, and a second lamp socket  140  structured for fastening to a right end portion of the lamp housing. 
     The lamps set  110  may include, for example, a pair of cold cathode fluorescent lamps (CCFLs) that are to be operated in a series connected circuit. Each lamp of set  110  includes a cylindrical lamp body  112 , a first electrode  114  at its left end and a second electrode  116  at its right end. 
     The lamp body  112  includes a glass lamp tube having, for example, a rod shape. The first electrode  114  and the second electrode  116  are formed at both end portions of the lamp body  112 . The lamp set  110  externally receives a relatively high voltage through its second electrodes  116  and responsively generates light. 
     The first electrode  114  and the second electrode  116  may respectively serve as a cold electrode and a hot electrode. The hot electrodes  116  are electrically connected to a power supply unit (not shown) such as, for example, to a DC to high voltage AC or DC converter or inverter. The first electrodes  114  interconnect to define an intermediate tap point in the series circuit and this tap point is desirably electrically connected back to the power supply unit to provide a tap-point feedback signal to the power supply unit. The power supply unit may use a voltage detected at the tap-point for determining how to stably drive the lamp set  110 . In the case where high voltages of opposite polarity are applied to the hot electrodes  116 , the tap point defined by interconnection of the first electrodes  114  will be at a voltage equal to or near the ground voltage or neutral output voltage of the power supply. 
     Although the embodiment of  FIG. 1  has two lamps in set  110 , alternatively, the lamp assembly  100  may operate with just one lamp  112 , or three lamps connected in series or in a series parallel combination. 
     The lamp housing  120  is preferably composed of an electrically conductive, optically reflective and easily workable metal such as aluminum or an alloy thereof and it may include a relatively rigid base plate  122  at its back, a somewhat flexible first sidewall  124  at its top and a larger second sidewall  126  at its bottom. The first socket  130  is used to electrically and mechanically connect the left end of the lamp housing  120  to the first electrodes  114  of the lamp set  110 . The second socket  140  is used to mechanically connect the right end of the lamp housing  120  to the second electrodes  116  while keeping the housing  120  electrically insulated from the second electrodes  116  of the lamp set  110 . In one embodiment, the light reflecting inner surfaces of the lamp housing  120  are coated with an electrically insulative and corrosion-preventing material (i.e., aluminum oxide) and thus it is not possible to make direct electrical contact to the lamp housing via this corrosion-preventing coating. 
     The inner surfaces of the base plate  122 , the first sidewall  124  and the second sidewall  126  define a receiving space for the lamp set  110 . An opening is defined over the region facing the inner portion of the base plate  122 . The lamp set  110  is received through this opening, and the light generated from the received lamp set  110  is output externally through this opening. The lamp housing  120  may reflect some of the light generated from the lamp set  110  towards the front. Thus, the inner surfaces of the lamp housing  120  may include a material having a great optical reflectivity such as a silvery or a white paint. Preservation of the optical reflectivity of this inner surface material is desirable and thus a transparent and/or corrosion-preventing coating will typically be applied over it. Additionally, the lamp housing  120  may include anti-corrosive electrical contact claddings placed elsewhere thereon (i.e., at portions  122   a ,  126   c ) where the electrical contact a claddings are made of nickel and where electrical connections are to be made to such clad portions (i.e., at portions  122   a ,  126   c ) as shall be described momentarily. 
     The base plate  122  includes a protruding terminal contact portion  122   a  to be mechanically and electrically connected to the first lamp socket  130 . 
     The first sidewall  124  and the second sidewall  126  protrude from the base plate  122 , and enclose a portion of a periphery of the lamp set  110 . First throughholes  124   a  and  124   b , and second throughholes  126   a  and  126   b  are formed through the first sidewall  124  and the second sidewall  126 , respectively, to mechanically and/or electrically couple the first and second lamp sockets  130  and  140  to the lamp housing  120  as shall be detailed herein. A lower sidewall extending portion  126   c  is formed as part of the second sidewall  126 . The sidewall extending portion  126   c  is more protrusive than the first sidewall  124  by a predetermined length. 
     The first lamp socket  130  is disposed in the receiving space of the lamp housing  120 . The first lamp socket  130  receives and fixes a first end portion of the lamps set  110 , and electrically connects the first electrodes  114  of the lamps set  110  to each other and to an electrically conductive portion (i.e.,  122   a ) of the lamp housing  120 . The lamp housing  120  includes a conductive material such as an aluminum containing back base surface for providing integral electrical coupling from the left end ( 112   a ) of the housing to the right end of the housing  120 . Thus, the first lamp socket  130  may receive a tap-point feedback signal from the first electrodes  114  of the lamps set  110  and it may couple that tap-point feedback signal to an external circuit (i.e., a power supply having wires  147 , not fully shown) provided at the right end of the housing by passing the return signal through the lamp housing  120 . 
     Hereinafter, the first lamp socket  130  will be described in detail with reference to the accompanying drawings. 
       FIG. 2  is an enlarged perspective view of the first lamp socket of the lamp assembly illustrated in  FIG. 1 .  FIG. 3  is a plan view of the first lamp socket of the lamp assembly illustrated in  FIG. 2 .  FIG. 4  is a partial cross-sectional view taken along a line l-l′ in  FIG. 2 . In  FIGS. 2 to 4 , the lamps set  110  and the lamp housing  120  are shown in a dotted line. 
     Referring to  FIGS. 2 to 4 , the first lamp socket  130  includes a first socket body  131  and a first terminal  132 . The socket body  131  may be made of an insulative material such as a plastic or ceramic while the first terminal  132  is made of an electrically conductive material such as a nickel clad spring metal. 
     The first socket body  131  has a receiving space to receive an end portion of the lamps set  110 . 
     The first terminal  132  is disposed in the receiving space of the first socket body  131  to electrically connect the first electrodes  114  of the lamps set  110  to each other and to the lamp housing  120 . The first terminal  132  includes a first electrodes fixing portion  132   a , a housing connecting portion  132   b  and an interconnect portion  132   c.    
     The first electrodes fixing portion  132   a  is electrically connected to the first electrodes  114  of the lamps set  110 , and fixes and supports the first electrodes  114 . In an exemplary embodiment, the first electrodes fixing portion  132   a  has a shape for clamp-wise gripping the first electrodes  114 . 
     The housing connecting portion  132   b  is electrically connected to the lamp housing  120 . The lamp housing  120  includes a terminal contact portion  122   a  protruding from a surface of the lamp housing  120  to be electrically connected to the housing connecting portion  132   b . As shown in  FIGS. 2 to 4 , the housing connecting portion  132   b  may have a spring-clip shape so that the terminal contact portion  122   a  may be resiliently inserted into electrical contact with the housing connecting portion  132   b.    
     The first electrodes fixing portion  132   a  and the housing connecting portion  132   b  are electrically connected to each other through the extension portion  132   c.    
     The first lamp socket  130  has an opening through which the lamps set  110  is received in the first lamp socket  130 . The first lamp socket  130  may further include a first cover  133  for covering the opening and thus protecting the interior of the first lamp socket  130  from entry of debris or other undesirable materials. 
     In  FIG. 2 , the first cover  133  is hingedly-coupled to the first socket body  131 . Thus, the first cover  133  may be rotated with respect to the first socket body  131 . After the lamps set  110  is positioned in the receiving space of the first socket body  131 , the first cover  133  is rotated to cover the lamps-receiving space of the first socket body  131 . Alternatively, the first cover  133  may be coupled to the first socket body  131  by using a flexible and plastically deformable material, or by various other methods. 
     A throughhole may be formed at the first lamp socket  130 . In an exemplary embodiment, the first lamp socket  130  has a throughhole  134  formed through a bottom surface of the first socket body  131 . The lamp housing  120  includes a terminal contact portion  122   a  protruding from a surface of the base plate  122  and inwardly extending into the first lamp socket  130  through the throughhole  134 . For example, the housing connecting portion  132   b  has a spring-clip shape into which the terminal contact portion  122   b  is inserted. 
     The first lamp socket  130  may further include a set of first coupling protrusions  135  formed on both outer sides of the first socket body  131 . The first coupling protrusions  135  are disposed in corresponding opposition to the first throughhole  124   a  of the first sidewall  124  and the second throughhole  126   a  of the second sidewall  126 . Thus, the first lamp socket  130  may be snap-fit fastened to the lamp housing  120  through the mating of the first coupling protrusions  135  and the first and second throughholes  124   a  and  126   a . In one embodiment, the first coupling protrusions  135  are made of a resilient and electrically insulative plastic or an alike material. In an alternative embodiment (not shown), the first coupling protrusions  135  are made of a resilient and electrically conductive metal or an alike material and may be used for providing electrical connection between the lamp housing and the first electrodes fixing portion  132   a.    
     The first lamp socket  130  may further include a dielectric separation rib  136  that protrudes from an inner surface of the first socket body  131  and extends between the first electrodes  114  of the lamps set  110 . The rib  136  may prevent an undesirable corona effect from developing due to the electric field that is generated between the first electrodes  114  of the lamps set during ignition. In  FIGS. 2 to 4 , the rib  136  is formed on the first socket body  131 . Alternatively, the rib  136  may be formed on the first cover  133  and brought between the lamps when the cover is closed, or it may be partially formed both on the first socket body  131  and the first cover  133 . In this case, the rib formed on the first socket body  131  and the rib formed on the second cover  133  may be arranged to mate with one another. 
     Referring again to  FIG. 1 , the second lamp socket  140  is disposed in the receiving space of the lamp housing  120 . The second lamp socket  140  receives and fixes the right end portions of the lamps set  110 , and electrically connects the second electrodes  116  respectively of the lamps set  110  to respective power supply a wires  147  externally provided from a lamps-driving power supply (not shown). Thus, the second lamp socket  140  applies a power voltage externally provided to the second electrodes  116  of the lamps set  110 . 
     Hereinafter, the second lamp socket  140  will be described in detail with reference to the accompanying drawings. 
       FIG. 5  is an enlarged perspective view of the second lamp socket of the lamp assembly illustrated in  FIG. 1 .  FIG. 6  is a plan view of the second lamp socket of the lamp assembly illustrated in  FIG. 5 .  FIG. 7  is a partial cross-sectional view taken along a line II-II′ in  FIG. 5 . 
     Referring to  FIGS. 5 to 7 , the second lamp socket  140  includes a second socket body  141  and a second terminal  142 . The socket body  141  may be made of an insulative material such as a plastic or ceramic while the second terminal  142  is made of an electrically conductive material such as a nickel clad spring metal. 
     The second socket body  141  has a receiving space for receiving an end portion of the lamps set  110 . 
     The second terminal  142  is disposed in the receiving space of the second socket body  141  to electrically connect the second electrodes  116  of the lamps set  110  to the respective power supply wires  147 . The second terminal  142  includes a second electrodes fixing portion  142   a , a wires connecting portion  142   b  and an interconnect portion  132   c.    
     The second electrodes fixing portion  142   a  is electrically connected to the second electrode  116  of the lamps set  110 , and fixes and supports the second electrodes  116 . In an exemplary embodiment, the second electrodes fixing portion  142   a  has a pair of clamp shaped clips for respectively gripping the second electrodes  116 . 
     The wires connecting portion  142   b  is electrically connected to the power supply wires  147 . The power supply wires  147  are electrically connected to a power supply unit (not shown). As shown in  FIGS. 5 to 7 , the wires connecting portion  142   b  may have a pair of cylindrically shaped, wire receiving clips so that the power supply wires  147  may be resiliently inserted into the wire connecting portion  142   b  for electrical contact therewith. Alternatively, the wire connecting portion  142   b  may have various other shapes so that the power supply wires  147  may be fixed and electrically connected to the second electrode fixing portion  142   a.    
     The second electrode fixing portion  142   a  and the wires connecting portion  142   b  are electrically connected to each other through the extension or interconnect portion  142   c.    
     The second lamp socket  140  has an opening through which the lamps set  110  is received in the second lamp socket  140 . The second lamp socket  140  may further include a second cover  143  for covering the opening. 
     In  FIG. 5 , the second cover  143  is hinge-coupled to the second socket body  141 . Thus, the second cover  143  may be rotated with respect to the second socket body  141 . After the lamps set  110  is positioned in the receiving space of the second socket body  141 , the second cover  143  is rotated to cover the second socket body  141  and protect its interior from entry of debris or other undesirable materials. Alternatively, the second cover  143  may be coupled to the second socket body  141  by using a flexible material, or by various other methods. 
     The second lamp socket  140  may further include second coupling protrusions  145  formed on both sides of the second socket body  141 . The second coupling protrusions  145  are disposed in corresponding opposition to the first throughhole  124   b  of the first sidewall  124  and the second throughhole  126   b  of the second sidewall  126 . Thus, the second lamp socket  140  may be snap-fit fastened to the lamp housing  120  through mating of the second coupling protrusions  145  with the first and second throughholes  124   b  and  126   b.    
     The second lamp socket  140  may further include a dielectric rib  146  that protrudes from an inner surface of the second socket body  141  and extends between the second electrodes  116  of the lamps  110 . The rib  146  may prevent an undesirable arcing or other effect due to a high voltage electric field that may be generated between the second electrodes  116 . In  FIGS. 5 to 7 , the rib  146  is formed on the second socket body  141 . Alternatively, the rib  146  may be formed on the second cover  143 , or may be formed on both the second socket body  141  and the second cover  143 . In this case, the rib formed on the first socket body  141  and the rib formed on the second cover  143  may be arranged to mate with one another. 
       FIGS. 8A and 8B  are partial perspective views illustrating an exemplary embodiment of the connection between a tap-return terminal and a tap connection portion of the lamp assembly illustrated in  FIG. 1 . 
     Referring to  FIGS. 8A and 8B , the lamp housing  120  may further include a tap connection portion  126   d.    
     The tap connection portion  126   d  protrudes from an electrically-conductive portion of the sidewall protruding portion  126   c  of the second sidewall  126  in a longitudinal direction of the lamp housing  120 . 
     The tap connection portion  126   d  is electrically connected to a tap-return wire  150  externally provided, and the tap-return wire  150  is electrically connected to a power supply unit (not shown). The power supply unit may thus receive a tap-point feedback signal from the first electrodes  114  that are positioned at the other end of the lamp housing  120 . 
     In one embodiment, high voltage power signals of opposite polarity are respectively applied to the second electrodes  116  to thereby ignite and drive the lamps set  110 . A feedback signal such as a voltage level reduced to a predetermined value is feedbacked from the juncture of the first electrodes  114 , and the low-voltage feedback signal is provided to the power supply unit through the lamp housing  120  and the tap-return wire  150 . The feedback signal can be used as a reference signal to control balanced luminance of the lamps in set  110 , and stability of the power supply unit may be secured by such balanced operation of the lamps set. As a result, the power supply unit may stably drive the lamps set  110 . 
     A tap-return terminal  152  is formed at an end portion of the tap wire  150  such that the tap connection portion  126   d  may be electrically connected to the tap wire  150 . 
     In  FIGS. 8A and 8B , the tap terminal  152  has a socket shape such that the tap connection portion  126   d  having a protrusion shape may be inserted into the tap terminal  152 . Alternatively, the tap terminal  152  may have various other shapes to be coupled to the tap connection portion  126   d . p In  FIGS. 8A and 8B , the tap connection portion  126   d  is formed on the sidewall protruding portion  126   c  of the second sidewall  126 . Alternatively, since the main body of lamp housing  120  is electrically conductive in one embodiment, the tap connection portion  126   d  may be formed at various other positions of the lamp housing  120  for allowing convenient coupling of the tap return wire  150  to the tap-point formed at the electrical juncture of first electrodes  114 . 
     In  FIGS. 8A and 8B , the tap-return wire  150  is just one wire. Alternatively, a number of integral but separate conduction paths may be formed through the lamp housing and the tap return wire set ( 150 ) may include two or more wires corresponding to the number of tap points defined by the lamps set ( 110 ). 
       FIGS. 9A and 9B  are partial perspective views illustrating another exemplary embodiment of the connection between a ground or tap terminal and a ground or tap connection portion of the lamp assembly illustrated in  FIG. 1 . 
     Referring to  FIGS. 9A and 9B , the lamp housing  120  has a ground connection portion  126   e  with a wire receiving groove (not shown) or other wire receiving and contacting means defined therein or thereon. 
     The ground connection portion  126   e  corresponds to a portion of a lower surface of the sidewall protruding portion  126   c  of the second sidewall  126 . 
     The ground connection portion  126   e  is electrically connected to the ground wire  150  externally provided, and the ground wire  150  is electrically connected to a power supply unit (not shown). The power supply unit may receive a feedback signal from the first electrodes  114 . 
     Particularly, a power voltage is applied to the second electrodes  116  to drive the lamps set  110 . A feedback signal such as a voltage level reduced to a predetermined value is feedbacked from the first electrodes  114 , and the feedback signal is provided to the power supply unit through the lamp housing  120  and the ground wire  150 . Thus, the feedback signal is used as a reference signal to control luminance of the lamps set  110 , and stability of the power supply unit may be secured. As a result, the power supply unit may stably drive the lamps set  110 . 
     An exposed grounding terminal  154  is formed at an end portion of the ground wire  150  such that the ground connection portion  126   e  may be electrically connected to the ground wire  150 . 
     In  FIGS. 9A and 9B , the grounding terminal  154  has a flat shape to be crimp-wise or otherwise connected to the ground connection portion  126   e  having a groove with a corresponding flat surface. Alternatively, the ground terminal  154  may have various other shapes to be coupled to the ground connection portion  126   e  via soldering, welding, taping or other ways. 
     The ground terminal  154  may be electrically connected to the ground connection portion  126   e  through a conductive adhesive, a conductive adhesive tape, a solder, etc. 
     In  FIGS. 9A and 9B , the ground connection portion  126   e  corresponds to a portion of the lower surface of the sidewall protruding portion  126   c  of the second sidewall  126 . Alternatively, since the lamp housing  120  is electrically conductive, the ground connection portion  126   e  may be formed at various other positions of the lamp housing  120 . 
     In  FIGS. 9A and 9B , the ground wire  150  includes one wire. Alternatively, the ground wire  150  may include two wires or more corresponding to the number of tap points in the lamps set  110 . 
       FIGS. 10A and 10B  are cross-sectional views illustrating a first lamp socket of a lamp assembly according to another exemplary embodiment. 
     Referring to  FIGS. 10A and 10B , a first lamp socket  170  includes a first socket body  171  made of an insulative material (i.e., plastic), a first terminal  172 , a first cover  173 , a throughhole  174 , a first coupling protrusion (not shown) and a rib  176 . 
     The first terminal  172  includes a first electrodes fixing portion  172   a , a housing connecting portion  172   b  and an extension portion  172   c.    
     In one embodiment, the first lamp socket  170  is substantially the same as the first lamp socket  130  illustrated in  FIGS. 2 to 4  except for the housing connecting portion  172   b . Thus, any further description will be omitted. 
     The housing connecting portion  172   b  outwardly extends from the insulative first lamp socket  171  through the throughhole  174 . The extending housing connecting portion  172   b  is electrically conductive makes electrical contact with a conductive contact portion of the inner surface of the base plate  122  of the lamp housing  120 . Thus, the first electrodes  114  of the lamps set  110  may be electrically connected to the lamp housing  120  through the first terminal  172 . 
     As shown in  FIGS. 10A and 10B , the housing connecting portion  172   b  has a resilient or spring structure for applying an elastic contact force to the base plate  122  of the lamp housing  120 , when the first lamp socket  170  and the lamp housing  120  is coupled to each other. Thus, the housing connecting portion  172   b  may make reliable and strong contact with the base plate  122  of the lamp housing  120 . 
     The base plate  122  of the lamp housing  120  of  FIGS. 10A-10B  does not include the terminal contact portion  122   a  shown in  FIGS. 2 to 4 . Thus, the lamp assembly may have a more simplified structure. 
       FIGS. 11A and 11B  are cross-sectional views illustrating a first lamp socket of a lamp assembly according to still another exemplary embodiment. 
     Referring to  FIGS. 11A and 11B , the first lamp socket  180  includes a first socket body  181 , a first terminal  182 , a first cover  183 , a throughhole  184 , a first coupling protrusion (not shown) and a rib  186 . 
     The first terminal  182  includes a first electrodes fixing portion  182   a , a housing connecting portion  182   b  and an extension portion  182   c.    
     The first lamp socket  180  is substantially the same as the first lamp socket  130  illustrated in  FIGS. 2 to 4  except for the housing connecting portion  182   b . Thus, any further description will be omitted. 
     The housing connecting portion  182   b  is electrically conductive and is formed on the insulative first socket body  181  to pass through the throughhole  184 . Particularly, the housing connecting portion  182   b  is formed on inner and outer surfaces of the first lamp socket body  181  that are adjacent to the throughhole  184  and a portion of the first lamp socket  181  that connects the inner and outer surfaces and defines the throughhole  184 . The housing connecting portion  182   b  makes contact with the extension portion  182   c  and an inner conductive surface portion of the base plate  122  of the lamp housing  120 . Thus, the first electrodes  114  of the lamps set  110  are electrically connected to the lamp housing  120  through the first terminal  182 . 
     The base plate  122  of the lamp housing  120  of  FIGS. 11A-11B  does not include the terminal contact portion  122   a  shown in  FIGS. 2 to 4 . Thus, the lamp assembly may have a more simplified structure. 
       FIG. 12  is an exploded perspective view illustrating a backlighting assembly  700  according to an exemplary embodiment. 
     Referring to  FIG. 12 , the backlighting assembly  700  includes a lamp assembly  100 , a light guiding member  200 , a light reflecting member  300  and a receiving container or tray  400 . 
     The lamp assembly  100  is substantially the same as the lamp assembly  100  illustrated in  FIG. 1 . Thus, any further description concerning substantially the same parts will be omitted. 
     The light guiding member  200  receives the light generated from the lamp assembly  100  at a side edge of the light guiding member and guides the light for projection upwardly to the overlying optical coupling member  500  and thereafter to the LCD panel  810 - 820  ( FIG. 13 ). 
     The light reflecting member  300  has, for example, a sheet shape, and reflects light leaked downwardly from the light guiding member  200  back upwardly to the light guiding member  200 . 
     The receiving container  400  includes a bottom plate  410  and a sidewall  420  protruding from the bottom plate  410 . The bottom plate  410  and the sidewall  420  define a receiving space, and the lamp assembly  100 , the light guiding member  200 , and the light reflecting member  300  are received in the receiving space. 
     The backlight assembly  700  may further include an optical coupling member  500 . The optical member  500  is disposed over the light guiding member  200 , and includes, for example, a light-diffusing plate  510  and at least one optical sheet  520 . The light-diffusing plate  510  receives the light that exits the light guiding member  200 , and diffuses the light. The optical sheet  520  receives the diffused light from the light-diffusing plate  510 , and improves optical characteristics of the diffused light such as polarization of the light. 
     The backlight assembly  700  illustrated in  FIG. 12  employs the lamp assembly  100  illustrated in  FIG. 1 . Here, the lamp assembly  100  has a ground structure using the ground terminal  152  and the ground connection portion  126   d  shown in  FIGS. 8A and 8B . Alternatively, the lamp assembly  100  may have a ground structure using the ground terminal  154  and the ground connection portion  126   e  shown in  FIGS. 9A and 9B . 
     Since the backlight assembly  700  illustrated in  FIG. 12  employs the lamp assembly  100  illustrated in  FIG. 1 , the backlight assembly  700  includes the first lamp socket  130  illustrated in  FIGS. 2 to 4 . Alternatively, the backlight assembly  700  may include the first lamp socket  170  illustrated in  FIGS. 10A to 10B . Alternatively, the backlight assembly  700  may include the first lamp socket  180  illustrated in  FIGS. 11A to 11B . 
       FIG. 13  is an exploded perspective view illustrating a liquid crystal display device  1000  according to an exemplary embodiment. 
     Referring to  FIG. 13 , the display device  1000  includes a backlighting assembly  700 , a display panel  800  and a chassis  900 . 
     The backlighting assembly  700  is substantially the same as the backlighting assembly  700  illustrated in  FIG. 12 . Thus, any further description concerning substantially the same parts will be omitted. 
     The display panel  800  includes a first substantially transparent substrate  810 , a second substantially transparent substrate  820  facing the first substrate  810  and a liquid crystal material layer (not shown) interposed between the first and second substrates  810  and  820 . 
     The first substrate  810  includes pixel electrodes (not shown) that are arranged in a matrix shape and made of a transparent conductive material. The first substrate  810  includes thin film transistors (TFTs) (not shown) each of which switches a driving signal of an associated pixel electrode. 
     The second substrate  820  includes one or more color filters (not shown) that selectively transmit lights having predetermined wavelengths (i.e., red, green and blue). The second substrate  820  includes a common electrode (not shown) that capacitively opposes the pixel electrodes of the first substrate  810  and is made of a transparent conductive material. 
     The display panel  800  may further include a printed circuit board (PCB)  830  and a printed circuit film  840 . The PCB  830  generates a driving signal driving the display panel  800 . The PCB  830  is electrically connected to an edge portion of the first substrate  810  through the printed circuit film  840 . 
     The driving signal from the PCB  830  generates an electric field between the first substrate  810  and the second substrate  820  to rearrange liquid crystal molecules of the liquid crystal layer interposed between the first substrate  810  and the second substrate  820 . Thus, optical transmissivity of the light provided from the optical member  500  is changed to display an image having a desired gray scale or colored intensities of the display device  1000 . 
     According to the present disclosure, a lamp assembly may include a first lamp socket structured so that a lamp is fastened to and coupled to a lamp housing, and cold electrodes of first and second lamps are electrically connected to the lamp housing having electrical conductivity. 
     Accordingly, since the cold electrodes may be electrically connected to a power supply unit through the lamp housing and thus grounded at a series tap point of the lamps, a conventional return wire may be omitted, thereby simplifying a structure of the lamp assembly. 
     Also, since the lamp socket electrically connects the lamp and a power supply wire to each other, a conventional soldering process may be omitted, thereby simplifying the manufacturing process of the lamp assembly. 
     Therefore, the number of parts of the lamp assembly may be reduced, and manufacturing process may be simplified, thereby reducing manufacturing cost of the lamp assembly. 
     Although exemplary embodiments have been described, it is understood that the scope of the inventive subject matter described herein should not be limited to specific aspects of these exemplary embodiments and that various changes and modifications can be made by one of ordinary skill in the art after having read this disclosure where the changes and modifications are within the spirit and scope of the present disclosure.