Abstract:
Various structures are disclosed to provide flat fluorescent lamps adapted to provide improved optical characteristics by reducing sodium elution from one or more glass plates. Related methods of manufacture are also provided. In one example, a flat fluorescent lamp includes a first plate and a second plate adapted to form a plurality of discharge chambers in combination with the first plate. A first elution preventive layer is provided on an inner surface of the second plate. A first fluorescent layer is provided above an inner surface of the first plate. A second fluorescent layer is provided above the first elution preventive layer. In another example, the first and second plates comprise sodalime glass. In another example, the elution preventive layer is adapted to prevent sodium eluted from the second plate from exceeding a predetermined sodium elution amount.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to Korean Patent Application No. 2006-0003268, filed in the Korean Intellectual Property Office, Republic of Korea, on Jan. 11, 2006, the disclosure of which is incorporated herein by reference in its entirety. 
       BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to flat fluorescent lamps and methods of manufacturing the same. More particularly, the present invention relates to improving the lifetime of flat fluorescent lamps and their associated light emissive characteristics by reducing sodium (Na) elution from glass plates. 
         [0004]    2. Description of Related Art 
         [0005]    Liquid crystal displays (LCDs) are one of the more widely used types of flat panel display devices. An LCD includes two transparent substrates provided with field-generating electrodes (i.e., a pixel electrode and a common electrode) and a liquid crystal (LC) layer interposed therebetween. The LCD displays images by applying voltages to the field-generating electrodes to generate an electric field in the LC layer, which controls the orientation of the LC molecules in the LC layer to affect the polarization of light passing therethrough. 
         [0006]    Light for the LCD is supplied by an internal source, such as a lamp contained in the LCD. For large LCD displays, flat fluorescent lamps have been developed which are disposed opposite to, and emit light toward, the display area of LCDs. Such flat fluorescent lamps can include an upper glass plate, a lower glass plate, and a plurality of discharge chambers. The upper plate can be processed to form the discharge chambers which are provided by coupling the upper plate with the lower plate. The upper and the lower plates can be formed of sodalime glass due to its manufacturing convenience and low cost. 
         [0007]    Sodalime glass includes sodium (Na) which exhibits high mobility. The sodium is eluted from the glass plates into the discharge chambers during high temperature manufacturing processes and in response to electric fields applied to the lamp during use. The eluted sodium reacts with mercury (Hg) in the discharge chambers to form amalgam, thereby reducing the amount of mercury in the discharge chambers and reducing light transmittance. As a result, the lifetime and light emissive characteristics of the flat fluorescent lamps are degraded. 
         [0008]    Therefore, there is a need for an improved flat fluorescent lamp that reduces sodium elution. In addition, there is a need for an improved method of manufacturing the same. 
       BRIEF SUMMARY 
       [0009]    In accordance with embodiments of the present invention further described herein, flat fluorescent lamps can be provided with improved optical characteristics by reducing sodium elution from one or more glass plates. Methods of manufacturing the lamps are also provided. 
         [0010]    In one embodiment, a flat fluorescent lamp includes a first plate, a second plate adapted to form a plurality of discharge chambers in combination with the first plate, a first elution preventive layer on an inner surface of the second plate, a first fluorescent layer above an inner surface of the first plate, and a second fluorescent layer above the first elution preventive layer. 
         [0011]    In another embodiment, the first elution preventive layer comprises at least one selected from the group consisting of silicon oxide, silicon nitride, and aluminum oxide. In another embodiment, the first and second plates comprise sodalime glass. 
         [0012]    In another embodiment, the second plate comprises chamber portions separated apart from the first plate to form the discharge chambers, partition portions adapted to separate the discharge chambers, and sealing portions at edges of the second plate. 
         [0013]    In another embodiment, a reflective layer is provided between the first plate and the first fluorescent layer. In another embodiment, a second elution preventive layer is provided between the first plate and the reflective layer. In another embodiment, a first protective layer is provided between the reflective layer and the first fluorescent layer, and a second protective layer is provided between the first elution preventive layer and the second fluorescent layer. 
         [0014]    In another embodiment, a flat fluorescent lamp includes a first plate, a second plate adapted to form a plurality of discharge chambers in combination with the first plate, and a first elution preventive layer on an inner surface of the second plate and adapted to prevent sodium eluted from the second plate from exceeding a predetermined sodium elution amount. 
         [0015]    In another embodiment, the sodium elution amount is in a range of about 0% wt to about 10 wt %. In another embodiment, the first elution preventive layer comprises at least one selected from the group consisting of: silicon oxide, silicon nitride, and aluminum oxide. In another embodiment, the flat fluorescent lamp further includes a first fluorescent layer above an inner surface of the first plate, and a second fluorescent layer above the first elution preventive layer. 
         [0016]    In another embodiment, a liquid crystal display (LCD) device includes a LCD panel adapted to display images, a driving circuit adapted to provide a plurality of data signals and gate signals to the LCD panel, a flat fluorescent lamp configured to provide light to the LCD panel, and an inverter adapted to provide a discharge voltage to the flat fluorescent lamp. In such an embodiment, the flat fluorescent lamp includes a first plate, a second plate adapted to form a plurality of discharge chambers in combination with the first plate, a first elution preventive layer on an inner surface of the second plate and adapted to prevent sodium eluted from the second plate from exceeding a predetermined sodium elution amount, a first fluorescent layer above an inner surface of the first plate, and a second fluorescent layer above the first elution preventive layer. 
         [0017]    In another embodiment, a method for manufacturing a flat fluorescent lamp includes forming a first fluorescent layer above an inner surface of a first plate, molding a second plate to have a desired shape, forming a first elution preventive layer on an inner surface of the second plate, forming a second fluorescent layer above the first elution preventive layer, and combining the first and second plates to form a plurality of discharge chambers, wherein the inner surfaces of the first and second plates face each other. 
         [0018]    In another embodiment, the first elution preventive layer comprises at least one selected from the group consisting of: silicon oxide, silicon nitride, and aluminum oxide. In another embodiment, the first and second plates comprise sodalime glass. In another embodiment, the first elution preventive layer is formed by a chemical vapor deposition (CVD) process. 
         [0019]    In another embodiment, the method further includes forming a reflective layer between the first plate and the first fluorescent layer. In another embodiment, the method further includes forming a second elution preventive layer between the first plate and the reflective layer. In another embodiment, the method further includes forming a first protective layer between the reflective layer and the first fluorescent layer, and forming a second protective layer between the first elution preventive layer and the second fluorescent layer. In another embodiment, the method further includes preventing sodium eluted from the second plate from exceeding a predetermined sodium elution amount. 
         [0020]    A better understanding of the above and many other features and advantages of the present invention may be obtained from a consideration of the detailed description of the exemplary embodiments thereof below, particularly if such consideration is made in conjunction with the several views of the appended drawings, wherein like reference numerals are used to identify like elements illustrated in one or more of the figures thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a perspective view of a flat fluorescent lamp in accordance with an embodiment of the present invention; 
           [0022]      FIG. 2  is a cross-sectional view taken along the line I-I′ of the flat fluorescent lamp of  FIG. 1  in accordance with an embodiment of the present invention; 
           [0023]      FIG. 3  is a cross-sectional view taken along the line II-II′ of the flat fluorescent lamp of  FIG. 1  in accordance with an embodiment of the present invention; 
           [0024]      FIG. 4  is a cross-sectional view of another flat fluorescent lamp in accordance with an embodiment of the present invention; 
           [0025]      FIGS. 5 and 6  are cross-sectional views showing process steps for forming a flat fluorescent lamp in accordance with an embodiment of the present invention; and, 
           [0026]      FIG. 7  is an exploded perspective view of a LCD in accordance with an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]      FIG. 1  is a perspective view of an embodiment of a flat fluorescent lamp  100  in accordance with an embodiment of the present invention.  FIG. 2  is a cross-sectional view taken along the line I-I′ of the flat fluorescent lamp  100  of  FIG. 1  in accordance with an embodiment of the present invention.  FIG. 3  is a cross-sectional view taken along the line II-II′ of the flat fluorescent lamp  100  of  FIG. 1  in accordance with an embodiment of the present invention. 
         [0028]    Referring to  FIGS. 1 to 3 , flat fluorescent lamp  100  includes a first plate  110  and a second plate  120 . Second plate  120  is coupled with first plate  110  to provide a plurality of discharge chambers  130 . Discharge chambers  130  emit light, are separated apart from one another, and exhibit a substantially rectangular shape. 
         [0029]    In response to electric power provided from an external inverter (not shown in  FIGS. 1 to 3 ), flat fluorescent lamp  100  generates plasma discharge in discharge chambers  130 . The plasma discharge emits ultraviolet rays which are converted to visible rays emitted from flat fluorescent lamp  100 . Flat fluorescent lamp  100  has a relatively large light-emitting area which increases its light-emitting efficiency. The internal structure of flat fluorescent lamp  100  is divided into discharge chambers  130  to provide substantially uniform luminance. 
         [0030]    First plate  110  has a substantially rectangular shape and is formed of sodalime glass. Second plate  120  is also formed of sodalime glass. First plate  100  and second plate  200  can further include ultraviolet blocking layers to prevent ultraviolet light from leaking through the first and second plates  110  and  120 . 
         [0031]    In one embodiment, second plate  120  is processed to have a desired shape by heating sodalime glass to a temperature equal to or greater than its softening point (i.e., to a temperature at which the sodalime glass becomes flexible enough to change shape). In one embodiment, second plate  120  has a softening point of about 727° C. The sodalime glass is then molded using blow molding techniques employing compressed air. In another embodiment, second plate  120  is processed to have a desired shape by heating the sodalime glass to a determined temperature and then molding the sodalime glass using a cast. 
         [0032]    The softening point of sodalime glass depends on its impurity contents. For example, the softening point can decrease as the impurity contents of the sodalime glass increases. Examples of such impurities include sodium (Na), potassium (K), calcium (Ca), and magnesium (Mg). 
         [0033]    Because of its high mobility, sodium can be eluted into discharge chambers  130  by high temperature manufacturing processes and electric fields applied to flat fluorescent lamp  100 . The eluted sodium reacts with mercury (Hg) in discharge chambers  130  to form amalgam, thereby reducing mercury and light transmittance to degrade the lifetime and emissive characteristics of flat fluorescent lamp  100 . 
         [0034]    Flat fluorescent lamp  100  includes a first elution preventive layer  140  to reduce sodium elution from second plate  120 . First elution preventive layer  140  is formed on an inner surface of second plate  120  facing first plate  110 . First elution preventive layer  140  can be formed of silicon oxide (SiO 2 ), silicon nitride (SiN x ), aluminum oxide (Al 2 O 3 ), or other materials. In one embodiment, first elution preventive layer  140  is formed by a chemical vapor deposition (CVD) process. 
         [0035]    Second plate  120  includes chamber portions  122 , partition portions  124 , and sealing portions  126 . Chamber portions  122  are separated apart from first plate  110  to form discharge chambers  130 . Partition portions  124  contact first plate  110  to separate discharge chambers  130 . Sealing portions  126  are disposed at edges of second plate  120  and contact first plate  110 . 
         [0036]    As shown in the cross-sectional view of flat fluorescent lamp  100  in  FIG. 2 , each of discharge chambers  130  are substantially arch-shaped, are connected to neighboring discharge chambers  130 , and are separated by a substantially uniform distance therebetween. In other embodiments, discharge chambers  130  can exhibit substantially semi-circular, quadrangular, or trapezoidal shapes, or other shapes. 
         [0037]    Second plate  120  can include one or more connection paths  128  between adjacent discharge chambers  130 . Connection paths  128  can be used to exhaust air from discharge chambers  130 , provide pathways where air or discharge gas can move between discharge chambers  130 , and uniformly distribute discharge gas in discharge chambers  130 . Connection paths  128  can be formed at the same time that second plate  120  is processed to have a desired shape. Connection paths  128  can have various shapes. For example, in one embodiment, connection paths  128  can be bent to have an “S” shape which can increase the path length between adjacent discharge chambers  130  to facilitate uniform discharge current flow and reduced channeling in discharge chambers  130 . 
         [0038]    First plate  110  and second plate  120  are coupled with an adhesive member  150 , such as frit (i.e. a mixture of glass and metal) having a lower melting point than glass. Adhesive member  150  is interposed between first plate  110  and sealing portion  126  of second plate  120 , heated and melted, and then solidified to combine first plate  110  and second plate  120 . In one embodiment, adhesive member  150  can be heated to a temperature in a range of about 400° C. to about 600° C. 
         [0039]    After first and second plates  110  and  120  are combined, air in discharge chambers  130  is exhausted to form a vacuum. Discharge gases, such as mercury, neon (Ne), argon (Ar), or other gasses are then injected into discharge chambers  130 . 
         [0040]    A pressure difference between inner and outer spaces of flat fluorescent lamp  100  causes partition portions  124  to adhere closely to first plate  110 . For example, in one embodiment, the pressure of discharge gases in discharge chambers  130  is in a range of about 50 torr to about 70 torr, and atmospheric pressure external to flat fluorescent lamp  100  is about 760 torr. The external force on flat fluorescent lamp  100  caused by this pressure difference forces partition portions  124  against first plate  110 . 
         [0041]    Flat fluorescent lamp  100  includes a first fluorescent layer  160  and a second fluorescent layer  165  above first plate  110  and second plate  120 , respectively. In  FIGS. 1 to 3 , second fluorescent layer  165  is formed on first elution preventive layer  140 . That is, first elution preventive layer  140  is disposed between second plate  120  and second fluorescent layer  165 . First and second fluorescent layers  160  and  165  can be excited by ultraviolet rays generated by plasma discharge inside discharge chambers  130 , thereby causing first and second flat fluorescent layers  160  and  165  to emit visible light. 
         [0042]    Flat fluorescent lamp  100  includes a reflective layer  170  between first plate  110  and first fluorescent layer  160 . Reflective layer  170  can reflect visible light emitted by first and second fluorescent layers  160  and  165  toward second plate  120 , thereby reducing light leakage through first plate  110 . In one embodiment, reflective layer  170  is about 80 μm thick, first fluorescent layer  160  is about 40 μm thick, and second fluorescent layer  165  is about 15 μm thick. First elution preventive layer  140  is formed on second plate  120  to prevent sodium from eluting from second plate  120 . Reflective layer  170  and first fluorescent layer  160  are relatively thick (e.g., second fluorescent layer can have a smaller thickness than first fluorescent layer  165 ) to prevent sodium from eluting from first plate  110 . 
         [0043]    Flat fluorescent lamp  100  includes external electrodes  180  formed on at least one outer surface of first plate  110  and second plate  120 . For example, external electrodes  180  can be formed across and at opposite ends of discharge chambers  130  and used to apply an electric field to discharge chambers  130 . External electrodes  180  formed on first plate  110  and second plate  120  can be connected by conductive clips (not shown). 
         [0044]    External electrodes  180  can be formed of conductive material, such as a silver paste including silver (Ag) and silicon oxide, a metal, a metal alloy, or other conductive material. In one embodiment, external electrodes  180  can be deposited by a spray, a spin coating, a dipping, or other deposition techniques. In another embodiment, external electrodes  180  are provided by a metal socket. 
         [0045]      FIG. 4  is a cross-sectional view of another embodiment of a flat fluorescent lamp  200  which is substantially identical to flat fluorescent lamp  100  of  FIG. 2 , except for the addition of first and second protective layers, and a second elution preventive layer. Accordingly, further explanation of previously described aspects of  FIG. 4  will be omitted in the following discussion. 
         [0046]    Flat fluorescent lamp  200  includes first plate  1   10  and second plate  120  which are coupled to provide discharge chambers  130 . First fluorescent layer  160  is formed above first plate  110 . Second fluorescent layer  165  is formed above second plate  120 . Reflective layer  170  is disposed between first plate  110  and first fluorescent layer  160 . First elution preventive layer  140  is disposed between second plate  120  and second fluorescent layer  165 . 
         [0047]    Flat fluorescent lamp  200  includes a second elution preventive layer  210  between first plate  110  and reflective layer  170 . Second elution preventive layer  210  reduces sodium elution from first plate  110 . In one embodiment, second elution preventive layer  210  is formed of silicon oxide, silicon nitride, aluminum oxide, or other material. In another embodiment, second preventive layer  210  is formed by a CVD process and is about 300 Å thick. 
         [0048]    Flat fluorescent lamp  200  includes first protective layer  220  between reflective layer  170  and first fluorescent layer  160 . First protective layer  220  prevents mercury in discharge chambers  130  from entering and reacting with first plate  110 , thereby reducing mercury loss from discharge chambers  130  and further reducing the formation of dark spots on first plate  110 . In one embodiment, first protective layer  220  is formed of yttrium oxide (Y 2 O 3 ) and is about 2 μm thick. 
         [0049]    Flat fluorescent lamp  200  includes a second protective layer  230  between first elution preventive layer  140  and second fluorescent layer  165 . Second protective layer  230  prevents mercury in discharge chambers  130  from entering and reacting with second plate  120 , thereby reducing mercury loss from discharge chambers  130  and further reducing the formation of dark spots on second plate  120 . In one embodiment, second protective layer  230  is formed of yttrium oxide and is about 1 μm thick. 
         [0050]    Hereinafter, a method for manufacturing a flat fluorescent lamp in accordance with an embodiment of the present invention will be described in detail with reference to  FIGS.5 and 6 . Referring to  FIG. 5 , reflective layer  170  and first fluorescent layer  160  are sequentially formed. In one embodiment, reflective layer  170  is about 80 μm thick and first fluorescent layer  160  is about 40 μm thick. 
         [0051]    Referring to  FIG. 6 , second plate  120  is processed to have a desired shape by heating second plate  120  to a temperature (e.g., about 750° C.) equal or greater than the softening point of the sodalime glass, and then compressing second plate  120  with air using blow molding techniques. In another embodiment, second plate  120  is processed to have a desired shape by heating and pressing sodalime glass with a cast. 
         [0052]    First elution preventive layer  140  is then formed on second plate  120  through, for example, a CVD process. In one embodiment, first elution preventive layer  140  is about 300 Å thick and can be formed of silicon oxide, silicon nitride, aluminum oxide, or other material. 
         [0053]    Table 1 shows the amount of sodium eluted from three embodiments of second plate  120  at a temperature of about 700° C. In example 1, second plate  120  is provided without first elution preventive layer  140 . In examples 2 and 3, first elution preventive layer  140  is provided on second plate  120  but is formed in different ways. Specifically, in Example 2, first elution preventive layer  140  is formed on second plate  120  before second plate  120  is formed into its desired shape. In example 3, first elution preventive layer  140  is formed on second plate  120  after second plate  120  is formed into its desired shape. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Example 1 
                 Example 2 
                 Example 3 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Sodium (wt %) 
                 21.0 
                 18.1 
                 0 
               
               
                   
                   
               
             
          
         
       
     
         [0054]    Referring to Table 1, although examples 2 and 3 both include first elution preventive layer  140 , approximately 18 wt % sodium is detected for example 2, whereas, approximately 0 wt % sodium is detected in example 3. Accordingly, it will be appreciated that first elution preventive layer  140  can reduce sodium elution from second plate  120 . In particular, where first elution preventive layer  140  is formed after second plate  120  is formed into its desired shape, the amount of eluted sodium can be prevented from rising above approximately 10 wt %, thereby increasing the lifetime of flat fluorescent lamp  100 . 
         [0055]    In another embodiment as shown in  FIG. 4 , a second elution preventive layer  210  can be formed between first plate  110  and reflective layer  170 . Second elution preventive layer  210  reduces the elution of sodium from first plate  110 . In one embodiment, second elution preventive layer  210  is about 300 Å and is formed by a CVD process. Second elution preventive layer  210  can be formed of silicon oxide, silicon nitride, aluminum oxide, or other material. 
         [0056]    A first protective layer  220  can be formed on reflective layer  170  before first fluorescent layer  160  is formed. First protective layer  220  prevents mercury in discharge chambers  130  from entering and reacting with first plate  110 , thereby reducing mercury loss and formation of black spots on first plate  110 . In one embodiment, first protective layer is formed of yttrium oxide and is about 2 μm thick. 
         [0057]    A second protective layer  230  can be formed on first elution preventive layer  140  before second fluorescent layer  165  is formed. Second protective layer  230  prevents mercury in discharge chambers  130  from entering and reacting with second plate  120 , thereby reducing mercury loss and formation of black spots on second plate  120 . In one embodiment, second protective layer is formed of yttrium oxide and is about 1 μm thick. 
         [0058]      FIG. 7  is an exploded perspective view of an LCD  500  in accordance with an embodiment of the present invention. LCD  500  includes a receiving container  510 , a flat fluorescent lamp  520 , and a display unit  600 . Receiving container  510  includes a bottom plate  512  and sidewalls  514  extending from bottom plate  512 . Sidewalls  514  have a double-bent structure to form an inverted U-shape to securely combine sidewalls  514  with other components such as a top chassis. In one embodiment, receiving container  510  is formed of a durable metal which is resistant to deformation. 
         [0059]    Flat fluorescent lamp  520  is disposed on receiving container  510  and emits light in response to a discharge voltage provided by an inverter  530 . Flat fluorescent lamp  520  can be implemented by flat fluorescent lamp  100  or  200  illustrated in  FIGS. 1 to 4 . Accordingly, further explanation of previously described aspects of  FIGS. 1 to 4  will be omitted in the following discussion. 
         [0060]    Display unit  600  includes a LCD panel  610  to display images using light provided by flat fluorescent lamp  520 . Display unit  600  also includes driving circuit  620  to drive LCD panel  610 . LCD panel  610  includes a first substrate  612 , a second substrate  614  facing first substrate  612 , and a liquid crystal  616  disposed therebetween. First substrate  612  includes thin film transistors (TFTs) arranged in a matrix type. Each TFT has a source electrode connected to a data line, a gate electrode connected to a gate line, and a drain electrode connected to a pixel electrode formed of transparent conductive material. Second substrate  615  includes color filters to represent primary colors red, green, and blue, and a common electrode formed of transparent conductive material. LCD panel  610  displays images by applying voltages to the pixel electrodes and the common electrodes to generate electric fields in the LC layer, which control the orientation of the LC molecules in the LC layer to affect the polarization of light provided from flat fluorescent lamp  520  passing through the LC layer. 
         [0061]    Driving circuit  620  includes a data printed circuit board (PCB)  622  to provide data signals to LCD panel  610 , a gate PCB  624  to provide gate signals to LCD panel  610 , data flexible printed circuit (FPC) films  626  to connect data PCB  622  to LCD panel  610 , and gate FPC films  628  to connect gate PCB  624  to LCD panel  610 . Data FPC film  626  and gate FPC film can each be implemented as a tape carrier package (TCP) or a chip on film (COF). Alternatively, gate PCB  624  can be replaced by signal lines formed on LCD panel  610  and gate FPC films. 
         [0062]    LCD  500  includes an inverter  530  to provide a discharge voltage. Inverter  530  is disposed at a backside of receiving container  510 . Inverter  530  converts a low voltage of alternating current to a high voltage of alternating current which is provided to external electrodes  180  of flat fluorescent lamp  520  through lamp wires (not shown). 
         [0063]    LCD  500  includes a diffusing plate  540  disposed on flat fluorescent lamp  520  and at least one optical sheet  550  on diffusing plate  540 . Diffusing plate  540  uniformly distributes light emitted from flat fluorescent lamp  520  and is disposed apart from flat fluorescent lamp  520 . Diffusing plate  540  can be formed of a transparent material that includes diffusing agents. In one embodiment, diffusing plate  540  is formed of polymethyl methacrylate (PMMA). 
         [0064]    Optical sheet  550  guides light diffused by diffusing plate  540  to increase luminance of LCD  500 . For example, optical sheet  550  can include a prism sheet to guide the diffused light toward a front of LCD  500 . Also, optical sheet  550  can include a diffusing film to further diffuse the light, and a reflective polarizing film to transmit portions of the light and reflect other portions. In various embodiments, one or more optical sheets  550  can be provided. 
         [0065]    LCD  500  includes buffering members  560  between flat fluorescent lamp  520  and receiving container  510  to support edges of flat fluorescent lamp  520 . Buffering members  560  are disposed at edges of flat fluorescent lamp  520  to separate and electrically insulate flat fluorescent lamp  520  from receiving container  510  which can be formed of metal. Buffering members  560  can be formed of elastic and insulating material such as silicon to protect flat fluorescent lamp  100  from impacts. 
         [0066]    LCD  500  includes a first mold  570  between flat fluorescent lamp  520  and diffusing plate  540 . First mold  570  fixes the edges of flat fluorescent lamp  520  with respect to receiving container  510  and supports the edges of diffusing plate  540 . First mold  570  also blocks external electrodes  180  of flat fluorescent lamp  520  to decrease shadows. First mold  570  can be implemented as one frame, two pieces (e.g., two U-shaped or L-shaped pieces), or four pieces (e.g., corresponding to its four sides). 
         [0067]    LCD  500  includes a second mold  580  disposed over first mold  570  to fix diffusing plate  540  and optical sheet  550  with respect to first mold  570 . Second mold  580  can be implemented as one frame, two pieces, or four pieces. 
         [0068]    LCD  500  includes a top chassis  590  which can be joined with receiving container  510  and can fix display unit  600  with second mold  580 . In one embodiment, top chassis  590  is formed of a durable metal. Data PCB  622  can be backwardly bent and disposed on a sidewall or a bottom side of receiving container  510 . 
         [0069]    In accordance with the embodiments of the present invention described and illustrated herein, a flat fluorescent lamp can include an elution preventive layer to reduce sodium elution from first or second plates formed of sodalime glass. As a result, the lifetime and light characteristics of the flat fluorescent lamp can be enhanced. By forming the elution preventive layer after the second plate is processed to have a desired shape, sodium elution can be more efficiently prevented. 
         [0070]    As those of skill in this art will appreciate, many modifications, substitutions, and variations can be made in the materials, apparatus, configurations, and methods of the present invention without departing from its spirit and scope. In light of this, the scope of the present invention should not be limited to that of the particular embodiments illustrated and described herein, as they are only exemplary in nature, but instead, should be fully commensurate with that of the claims appended hereafter and their functional equivalents.