Patent Publication Number: US-8125135-B2

Title: Field emission display device

Description:
BACKGROUND 
     The present disclosure herein relates to field emission display devices and, more particularly, to a field emission display device including a substrate with an anode electrode. 
     A field emission display (FED) is a type of a flat panel display (FPD) which is thin and operates with a low voltage. An FED is a display device in which images are implemented by light emission of phosphor. 
     In the FED, electrons emitted from a cathode electrode collide with phosphor to emit light. The emitted light is implemented as an image by passing an anode electrode and a glass substrate. A transparent electrode containing indium tin oxide is well known as the anode electrode. However, because light transmittance of the transparent electrode is lower than 100 percent, luminance of light passing the transparent electrode decreases. 
     SUMMARY 
     The present disclosure provides a field emission display capable of improving luminance. 
     Embodiments of the inventive concept provide a field emission display device (FED) which includes a first substrate, a phosphor layer on the first substrate, and an anode electrode on the phosphor layer. 
     According to some embodiments of the inventive concept, the FED may further include an auxiliary electrode frame which is disposed on the edge of the anode electrode and extends toward the first substrate. 
     According to other embodiments of the inventive concept, the FED may further include first auxiliary electrode patterns which are interposed between the first substrate and the phosphor layer and extend in a first direction. 
     According to other embodiments of the inventive concept, the FED may further include second auxiliary electrode patterns which extends in a second direction crossing the first direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the inventive concept, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the inventive concept and, together with the description, serve to explain principles of the inventive concept. In the drawings: 
         FIGS. 1 to 10B  are views illustrating field emission display devices according to embodiments of the inventive concept. 
         FIGS. 11 to 17B  are views illustrating methods for fabricating a field emission display device according to embodiments of the inventive concept. 
         FIGS. 18 and 19  are views illustrating effects of field emission display devices according to embodiments of the inventive concept. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the inventive concept are shown. However, the inventive concept may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. In this specification, it will also be understood that when a element is referred to as being “on” another element or substrate, it can be directly on the another element or substrate, or intervening elements may also be present. Like numbers refer to like elements throughout. 
     As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it may be directly connected or coupled to the other element or intervening elements may be present. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Referring to  FIG. 1 , a field emission display device (FED) according to an embodiment of the inventive concept will now be described in detail. A phosphor layer  110  is provided on a first substrate  100 . The first substrate  100  may be a transparent substrate including a glass substrate. The phosphor layer  110  may include phosphor. An anode electrode  120  is disposed on the phosphor layer  110 . The anode electrode  120  may include a conductive material having sheet resistance of 1000 ohms/square or less. Preferably, the anode electrode  120  may include a conductive material having sheet resistance of 100 ohms/square or less. The anode electrode  120  may include aluminum (Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt), tungsten (W) or combinations thereof. When the sheet resistance of the anode electrode  120  is 1000 ohms/square or greater, arcing may arise from charging. The anode electrode  120  may provide electrodes to the phosphor layer  110 . 
     A second substrate  200  is provided to face the first substrate  100 . Cathode electrodes  210  are provided on the second substrate  200 . Gate electrodes  220  may be provided on the cathode electrodes  210 . Insulating layers  215  may be further interposed between the cathode electrodes  210  and the gate electrodes  220 . Emitters  230  may be provided in regions adjacent to laminate structures of the cathode electrodes  210  and the gate electrode  220  on the second substrate  200 . For example, the emitters  230  may be disposed between the laminate structures of the cathode electrodes  210  and the gate electrodes  220 . 
     When a voltage is applied to the cathode electrodes  210  and the gate electrodes  220 , electrons are emitted from the emitters  230  due to a difference in voltage between both the electrodes  210  and  220 . The emitted electrons may collide with phosphor of the phosphor layer  110  after passing the anode electrode  120 . The phosphor transitions to an excited state due to the collision with the electrons and emits lights while retuning to a ground state. The light may implement an image by passing the first substrate  100 . The anode electrode  120  may induce the electrons in a direction of the phosphor layer  110 . The anode electrode  120  may reflect the electrons colliding with the phosphor in the direction of the phosphor layer  110 . The anode electrode  120  may prevent accumulation of the electrons at the phosphor layer  110  to maintain characteristics of the phosphor layer  110 . 
     Referring to  FIGS. 2A and 2B , a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail.  FIG. 2B  is a three-dimensional diagram of an anode area shown in  FIG. 2A . A phosphor layer  110  is provided on a first substrate  100 . An anode electrode  120  is provided on the phosphor layer  110 . The anode electrode  120  may include a conductive material having sheet resistance of 1000 ohms/square or less. Preferably, the anode electrode may include a conductive material of 100 ohms/square or less. The anode electrode  120  may include, for example, aluminum (Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt), tungsten (W) or combinations thereof. 
     An auxiliary electrode frame  125  may be interposed between the edge of the anode electrode  120  and the first substrate  100 . The auxiliary electrode frame  125  may include at least one selected from the group consisting of silver (Ag), copper (Cu), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), platinum (Pt), tungsten (W), indium tin oxide, indium zinc oxide, and tin oxide. The auxiliary electrode frame  125  may be electrically connected to the anode electrode  120 . The auxiliary electrode frame  125  may provide an electrical path to discharge electrons which reaches the phosphor layer  110  after transmitting the anode electrode  120 . The auxiliary electrode frame  125  may prevent accumulation of electrons in the phosphor layer  110  so as to suppress deterioration in characteristics of the phosphor layer  110 . The auxiliary electrode frame  125  may promote adherence between the anode electrode  120  and the phosphor layer  110 . 
     A second substrate  200  is provided to face the first substrate  100 . Cathode electrodes  210  are provided on the second substrate  200 . Gate electrodes  220  may be provided on the cathode electrodes  210 . Insulating layers  215  may be further interposed between the cathode electrodes  210  and the gate electrodes  220 . Emitters  230  may be provided in regions adjacent to laminate structures of the cathode electrodes  210  and the gate electrode  220 . For example, the emitters  230  may be disposed between the laminate structures of the cathode electrodes  210  and the gate electrodes  220 . 
     Referring to  FIGS. 3A and 3B , a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail.  FIG. 3B  is a three-dimensional diagram of an anode area shown in  FIG. 3A . A phosphor layer  110  is provided on a first substrate  100 . An anode electrode  120  is provided on the phosphor layer  110 . Auxiliary electrode frames  125   a  and  125   b  may be interposed between the edge of the anode electrode  120  and the first substrate  100 . The phosphor layer  110  may be surrounded by the first substrate  100 , the anode electrode  120 , and the auxiliary electrode frames  125   a  and  125   b . The auxiliary electrode frames  125   a  and  125   b  may include a first auxiliary electrode frame  125   a  that is adjacent to the first substrate  100  and a second auxiliary electrode frame  125   b  that is in contact with the first auxiliary electrode frame  125   a  and is adjacent to the anode electrode  120 . 
     The first auxiliary electrode frame  125   a  may include at least one selected from the group consisting of silver (Ag), copper (Cu), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), platinum (Pt), tungsten (W), indium tin oxide, indium zinc oxide, and tin oxide. The second auxiliary electrode frame  125   b  may include at least one selected from the group consisting of silver (Ag), copper (Cu), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), platinum (Pt), tungsten (W), indium tin oxide, indium zinc oxide, and tin oxide. 
     First auxiliary electrode patterns  127   a  may be provided between the first substrate  100  and the phosphor layer  110 . The first auxiliary electrode patterns  127   a  may be surrounded by the phosphor layer  110 . The first auxiliary electrode patterns  127   a  may have the same height as the first auxiliary electrode frame  125   a . The first auxiliary electrode pattern  127   a  may include a conductive material. The first auxiliary electrode patterns  127   a  may include at least one selected from the group consisting of silver (Ag), copper (Cu), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), platinum (Pt), tungsten (W), indium tin oxide, indium zinc oxide, and tin oxide. The first auxiliary electrode patterns  127   a  may be disposed on a region defined by the first auxiliary electrode frame  125   a  and may divide the region into a plurality of regions. For example, a stripe patterned frame may be defined by the first auxiliary electrode frame  125   a  and the first auxiliary electrode patterns  127   a.    
     A second substrate  200  is provided to face the first substrate  100 . Cathode electrodes  210  are provided on the second substrate  200 . Gate electrodes  220  may be provided on the cathode electrodes  210 . Insulating layers  215  may be further interposed between the cathode electrodes  210  and the gate electrodes  220 . Emitters  230  may be provided on regions adjacent to laminate structures of the cathode electrodes  210  and the gate electrode  220 . For example, the emitters  230  may be disposed between the laminate structures of the cathode electrodes  210  and the gate electrodes  220 . 
     Referring to  FIGS. 4A and 4B , a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail.  FIG. 4B  is a three-dimensional diagram of an anode area shown in  FIG. 4A . Referring to  FIG. 4B , second auxiliary electrode patterns  127   b  may be further provided between the first substrate  100  and the phosphor layer  110  shown in  FIG. 3   b . The second auxiliary electrode patterns  127   b  may be electrically connected to the first auxiliary electrode frame  125   a  and the first auxiliary electrode patterns  127   a . The second auxiliary electrode patterns  127   b  may be disposed on a region defined by the first auxiliary electrode frame  125   a  and the first auxiliary electrode patterns  127   a  and may divide the region into a plurality of regions. For example, a lattice patterned frame may be defined by the first auxiliary electrode frame  125   a , the first auxiliary electrode patterns  127   a , and the second auxiliary electrode patterns  127   b.    
     The second auxiliary electrode patterns  127   b  may be a conductive material. The second auxiliary electrode patterns  127   b  may include at least one selected from the group consisting of silver (Ag), copper (Cu), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), platinum (Pt), tungsten (W), indium tin oxide, indium zinc oxide, and tin oxide. Driving stability of the FED may be ensured by the first auxiliary electrode patterns  127   a  and the second auxiliary electrode patterns  127   b.    
     A second substrate  200  is provided to face the first substrate  100 . Cathode electrodes  210  are provided on the second substrate  200 . Gate electrodes  220  may be provided on the cathode electrodes  210 . Insulating layers  215  may be further interposed between the cathode electrodes  210  and the gate electrodes  220 . Emitters  230  may be provided on regions adjacent to laminate structures of the cathode electrodes  210  and the gate electrode  220 . For example, the emitters  230  may be disposed between the laminate structures of the cathode electrodes  210  and the gate electrodes  220 . 
     Referring to  FIGS. 5A and 5B , a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail.  FIG. 5B  is a three-dimensional diagram of an anode area shown in  FIG. 5A . On a first substrate  100 , an anode electrode  120  may be provided with a projection protruded in a direction of the first substrate  100 . The projection may be in contact with the edge of the first substrate  100 . A phosphor layer  110  may be provided in a region defined by the anode electrode  120  and the first substrate  100 . The phosphor layer  110  may be surrounded by the anode electrode  120  and the first substrate  100 . 
     A second substrate  200  is provided to face the first substrate  100 . Cathode electrodes  210  are provided on the second substrate  200 . Gate electrodes  220  may be provided on the cathode electrodes  210 . Insulating layers  215  may be further interposed between the cathode electrodes  210  and the gate electrodes  220 . Emitters  230  may be provided on regions adjacent to laminate structures of the cathode electrodes  210  and the gate electrode  220 . For example, the emitters  230  may be disposed between the laminate structures of the cathode electrodes  210  and the gate electrodes  220 . 
     Referring to  FIGS. 6A and 6B , a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail.  FIG. 6B  is a three-dimensional diagram of an anode area shown in  FIG. 6A . On a first substrate  100 , an anode electrode  120  may be provided with a projection extending in a direction of the first substrate  100 . The projection may be disposed at the edge of the anode electrode  120 . 
     An auxiliary electrode frame  125  may be interposed between the projection of the anode electrode  120  and the first substrate  100 . The auxiliary electrode frame  125  may include at least one selected from the group consisting of silver (Ag), copper (Cu), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), platinum (Pt), tungsten (W), indium tin oxide, indium zinc oxide, and tin oxide. 
     A phosphor layer  110  may be provided in a region defined by the anode electrode  120 , the first substrate  100 , and the auxiliary electrode frame  125 . The phosphor layer  110  may be surrounded by the anode electrode  120 , the first substrate  100 , and the auxiliary electrode frame  125 . 
     A second substrate  200  may be provided to face the first substrate  100 . Cathode electrodes  210  are provided on the second substrate  200 . Gate electrodes  220  may be provided on the cathode electrodes  210 . Insulating layers  215  may be further interposed between the cathode electrodes  210  and the gate electrodes  220 . Emitters  230  may be provided at regions adjacent to laminate structures of the cathode electrodes  210  and the gate electrode  220 . For example, the emitters  230  may be disposed between the laminate structures of the cathode electrodes  210  and the gate electrodes  220 . 
     Referring to  FIGS. 7A and 7B , a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail.  FIG. 7B  is a three-dimensional diagram of an anode area shown in  FIG. 7A . On a first substrate  100 , an anode electrode  120  is provided with a projection protruded in a direction of the first substrate  100 . The projection may be disposed on the edge of the anode electrode  120 . An auxiliary electrode frame  125  may be provided between the projection of the anode electrode  120  and the edge of the first substrate  100 . A phosphor layer  110  may be provided in a region defined by the first substrate  100 , the anode electrode  120 , and the auxiliary electrode frame  125 . The phosphor layer  110  may be surrounded by the first substrate  100 , the anode electrode  120 , and the auxiliary electrode frame  125 . 
     First auxiliary electrode patterns  127   a  may be provided in a region defined by the auxiliary electrode frame  125 . The first auxiliary electrode patterns  127   a  may be interposed between the first substrate  100  and the phosphor layer  110 . The height of the auxiliary electrode frame  125  may be substantially equal to that of the first auxiliary electrode patterns  127   a . The auxiliary electrode frame  125  and the first auxiliary electrode patterns  127   a  may be electrically connected to each other. 
     Referring to  FIGS. 8A and 8B , a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail.  FIG. 8B  is a three-dimensional diagram of an anode area shown in  FIG. 8A . Second auxiliary electrode patterns  127   b  may be further provided on the structure shown in  FIG. 7B  in a direction crossing an extending direction of the first auxiliary electrode patterns  127   a . The second auxiliary electrode patterns  127   b  may be disposed in a region defined by the auxiliary electrode frame  125  and the first auxiliary electrode patterns  127   a  and may divide the region into a plurality of regions. The second auxiliary electrode patterns  127   b  may have the same height as the auxiliary electrode frame  125  and the first auxiliary electrode patterns  127   a . The second auxiliary electrode patterns  127   b  may be spaced apart from the anode electrode  120 . A phosphor layer  110  may be interposed between the second auxiliary electrode patterns  127   b  and the anode electrode  120 . 
     A second substrate  200  is provided to face the first substrate  100 . Cathode electrodes  210  are provided on the second substrate  200 . Gate electrodes  220  may be provided on the cathode electrodes  210 . Insulating layers  215  may be further interposed between the cathode electrodes  210  and the gate electrodes  220 . Emitters  230  may be provided on regions adjacent to laminate structures of the cathode electrodes  210  and the gate electrode  220 . For example, the emitters  230  may be disposed between the laminate structures of the cathode electrodes  210  and the gate electrodes  220 . 
     Referring to  FIGS. 9A and 9B , a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail.  FIG. 9B  is a three-dimensional diagram of an anode area shown in  FIG. 9A . A phosphor layer  110  is provided on a first substrate  100 . On the phosphor layer  110 , an anode electrode  120  is provided with a projection facing toward the first substrate  100 . The projection may be disposed on the edge of the anode electrode  120 . Auxiliary electrode frames  125   a  and  125   b  may be provided between the projection and the edge of the first substrate  100 . The phosphor layer  110  may be disposed in a region defined by the fist substrate  100 , the auxiliary electrode frames  125   a  and  125   b , and the anode electrode  120 . The auxiliary electrode frames  125   a  and  125   b  may include at least two layers. The auxiliary electrode frames  125   a  and  125   b  may include first auxiliary electrode frame  125   a  adjacent to the first substrate  100  and second auxiliary electrode frame  125   b  adjacent to the anode electrode  120 . 
     First auxiliary electrode patterns  127   a  may be provided between the first substrate  100  and the phosphor layer  110 . The first auxiliary electrode patterns  127   a  may be disposed in a region defined by the first auxiliary electrode frame  125   a  and may be electrically connected to the first auxiliary electrode frame  125   a.    
     A second substrate  200  is provided to face the first substrate  100 . Cathode electrodes  210  are provided on the second substrate  200 . Gate electrodes  220  may be provided on the cathode electrodes  210 . Insulating layers  215  may be further interposed between the cathode electrodes  210  and the gate electrodes  220 . Emitters  230  may be provided on regions adjacent to laminate structures of the cathode electrodes  210  and the gate electrode  220 . For example, the emitters  230  may be disposed between the laminate structures of the cathode electrodes  210  and the gate electrodes  220 . 
     Referring to  FIGS. 10A and 10B , a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail.  FIG. 10B  is a three-dimensional diagram of an anode area shown in  FIG. 10A . Second auxiliary electrode patterns  127   b  may be provided in a direction crossing the first auxiliary electrode patterns  127   a  shown in  FIG. 9B . The second auxiliary electrode patterns  127   b  may be electrically connected to the first auxiliary electrode frame  125   a  and the first auxiliary electrode patterns  127   a.    
     A second substrate  200  is provided to face the first substrate  100 . Cathode electrodes  210  are provided on the second substrate  200 . Gate electrodes  220  may be provided on the cathode electrodes  210 . Insulating layers  215  may be further interposed between the cathode electrodes  210  and the gate electrodes  220 . Emitters  230  may be provided on regions adjacent to laminate structures of the cathode electrodes  210  and the gate electrode  220 . For example, the emitters  230  may be disposed between the laminate structures of the cathode electrodes  210  and the gate electrodes  220 . 
     Referring to  FIG. 11 , a method for fabricating a field emission display device (FED) according to an embodiment of the inventive concept will now be described in detail. A phosphor layer  110  is formed on a first substrate  100 . The phosphor layer  110  may be formed by conventional film forming methods including a printing method, a slurry method, a lithography method, and an electrophoresis method. An anode electrode  120  is formed on the phosphor layer  110 . The anode electrode  120  may include a conductive material having sheet resistance of 1000 ohms/square or less. Preferably, the anode electrode  120  may include a conductive material having sheet resistance of 100 ohms/square or less. For example, the anode electrode  120  may include aluminum (Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt), tungsten (W) or combinations thereof. The anode electrode  120  may be formed by transferring a film coated with a conductive material onto the phosphor layer  110  and baking the transferred film. Meanwhile, the anode electrode  120  may be formed by conventional conductive thin-film forming methods including a sputtering method, a vacuum evaporation method, and a printing method. As a result, an anode area shown in  FIG. 1  may be formed. 
     Referring to  FIGS. 12A to 12C , a method for fabricating a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail. Referring to  FIG. 12A , an auxiliary electrode layer  123  may be formed on a first substrate  100 . The first substrate  100  may be a transparent substrate such as, for example, a glass substrate. The auxiliary electrode layer  123 , for example, may include at least one selected from the group consisting of silver (Ag), copper (Cu), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), platinum (Pt), tungsten (W), indium tin oxide, indium zinc oxide, and tin oxide. The auxiliary electrode layer  123  may be formed by conventional thin-film forming methods including a printing method, a metal powder sintering method, a sputtering method, a vacuum evaporation method, a chemical vapor deposition (CVD) method. 
     Referring to  FIG. 12B , an auxiliary electrode frame  125  is formed by patterning the auxiliary electrode layer  123 . Alternatively, the auxiliary electrode frame  125  may be formed according to the step of forming the auxiliary electrode layer  123  without performing the patterning. 
     A phosphor layer  110  is formed on a region defined by the auxiliary electrode frame  125  on the first substrate  100 . The phosphor layer  110  may be formed by conventional film forming methods including a printing method, a slurry method, a lithography method, and an electrophoresis method. An intermediate layer  115  may be further formed on the phosphor layer  110 . The intermediate layer  115  may be formed by spin-coating a resin emulsion such as, for example, acryl. 
     Referring to  FIG. 12C , an anode electrode  120  is formed on the phosphor layer  110 . The anode electrode  120  may be formed by transferring a film coated with a conductive material onto the phosphor layer  110  and baking the transferred film. While the transferred film is baked, the intermediate layer  115  may be removed. Alternatively, the anode electrode  120  may be formed by a conventional conductive thin film forming method including a lacquer method and an emulsion method. As a result, an anode area shown in  FIG. 2A  may be formed. 
     Referring to  FIGS. 13A to 13C , a method for fabricating a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail. Referring to  FIG. 13A , a first auxiliary electrode frame  125   a  may be formed on a first substrate  100 . First auxiliary electrode patterns  127   a  may be formed on the first substrate  100  within the first auxiliary electrode frame  125   a . The first auxiliary electrode frame  125   a  and the first auxiliary electrode patterns  127   a  may be formed by forming a first auxiliary electrode layer (not shown) and patterning the same. When the first auxiliary electrode frame  125   a  and the first auxiliary electrode patterns  127   a  are formed, the second auxiliary electrode patterns  127   b  of  FIG. 4B  may be further formed. The first auxiliary electrode frame  125   a  and the auxiliary electrode patterns  127   a  and  127   b  may be formed by the same patterning process. 
     Referring to  FIG. 13B , a second auxiliary electrode frame  125   b  may be formed on the first substrate  100 . The second auxiliary electrode frame  125   b  may be formed by, for example, forming printing masks  122  on the substrate  100  to expose the first auxiliary electrode frame  125   a , coating a second auxiliary electrode layer (not shown) on the exposed first auxiliary electrode frame  125   a  and then baking the second auxiliary electrode layer. The printing masks  122  may be removed before and/or after baking the second auxiliary electrode layer. Alternatively, unlike illustrated, the second auxiliary electrode frame  125   b  may be formed by conventional thin-film forming methods including a sputtering method, a vacuum evaporation method, and a chemical vapor deposition (CVD) method 
     Referring to  FIG. 13C , a phosphor layer  110  may be formed in a region defined by the first auxiliary electrode frame  125   a  and the second auxiliary electrode frame  125   b  on the first substrate  100 . The phosphor layer  110  may be formed by conventional film forming methods including a printing method, a slurry method, a lithography method, and an electrophoresis method. 
     An anode electrode  120  may be formed on the phosphor layer  110 . The anode electrode  120  may be formed such that its edge is in contact with the second auxiliary electrode frame  125   b . The anode electrode  120  may be formed by a conventional conductive thin film forming method including a lacquer method and an emulsion method. As a result, an anode area shown in  FIGS. 3A and 4A  may be formed. 
     Referring to  FIGS. 14A and 14B , a method for fabricating a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail. Referring to  FIG. 14A , a phosphor layer  110  is formed on a first substrate  100 . The phosphor layer  110  may be formed by forming phosphor printing masks  109  on the first substrate  100  to expose a portion of the first substrate  100 , coating phosphor on the exposed portion of the substrate  100 , and drying the coated phosphor. The phosphor printing mask  109  may be removed before and/or after drying the coated phosphor. Prior to formation of the anode electrode  120 , an intermediate layer (not shown) may be further formed to cover the phosphor layer  110 . 
     Referring to  FIG. 14B , an anode electrode  120  may be formed on the first substrate  100  to cover the phosphor layer  110 . For example, the anode electrode  120  may be formed by transferring a film coated with a conductive material onto the phosphor layer  110  and baking the transferred film. While the transferred film is baked, the intermediate layer (not shown) may be removed. Alternatively, the anode electrode  120  may be formed by a conventional conductive thin film forming method including a lacquer method and an emulsion method. As a result, an anode area shown in  FIG. 5A  may be formed. 
     Referring to  FIGS. 15A and 15B , a method for fabricating a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail. Referring to  FIG. 15A , an auxiliary electrode frame  125  may be prepared on a first substrate  100 . A phosphor layer  110  is formed on the first substrate  100 . The phosphor layer  110  may fill a region defined by the auxiliary electrode frame  125  on the first substrate  100 . The phosphor layer  110  may be formed to expose its top surface and a portion of its side surface. An intermediate layer  115  may be formed on the exposed top surface of the phosphor layer  110  and on the exposed the portion of the side surface of the phosphor layer  110 . 
     Referring to  FIG. 15B , an anode electrode  120  is formed to cover the phosphor layer  110 . The anode electrode  120  may be formed to include a projection that is in contact with the auxiliary electrode frame  125 . For example, the anode electrode  120  may be formed by transferring a film coated with a conductive material onto the phosphor layer  110  and baking the transferred film. The intermediate layer  115  may be removed while baking the transferred film. Alternatively, the anode electrode  120  may be formed by a conventional conductive thin film forming method including a lacquer method and an emulsion method. As a result, an anode area shown in  FIG. 6A  may be formed. 
     Referring to  FIGS. 16A and 16B , a method for fabricating a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail. Referring to  FIG. 16A , an auxiliary electrode frame  125  and first auxiliary electrode patterns  127   a  may be formed on a first substrate  100 . The Second auxiliary electrode patterns  127   b  of  FIG. 8B  may be further formed during formation of the auxiliary electrode frame  125  and the first auxiliary electrode patterns  127   a . A phosphor layer  110  may be formed on the first substrate  100 . The phosphor layer  110  may fill a region defined by the auxiliary electrode frame  125  and the first auxiliary electrode patterns  127   a . The phosphor layer  110  may be formed to expose its top surface and a portion of its side surface that is not contact with the auxiliary electrode frame  125 . 
     Referring to  FIG. 16B , an anode electrode  120  may be formed on the auxiliary electrode frame  125  to cover the phosphor layer  110 . The anode electrode  120  may be formed to cover the exposed portion of the phosphor layer  110 . As a result, an anode area shown in  FIGS. 7A and 8A  may be formed. 
     Referring to  FIGS. 17A and 17B , a method for fabricating a field emission display device (FED) according to another embodiment of the inventive concept will now be described in detail. Referring to  FIG. 17A , a first auxiliary electrode  125   a  and first auxiliary electrode patterns  127   a  may be formed on a first substrate  100 . Second auxiliary electrode patterns  127   b  of  FIG. 10B  may be further formed on the first substrate  100  to cross the first auxiliary electrode patterns  127   a . A second auxiliary electrode frame  125   b  may be formed on the first auxiliary electrode frame  125   a . For example, the second auxiliary electrode frame  125   b  may be formed by forming mask patterns (not shown) on the first substrate  100  to expose the first auxiliary electrode frame  125   a , coating a conductive material on the exposed first auxiliary electrode frame  125   a , and baking the coated conductive material. The mask patterns may be removed before and/or after baking the coated conductive material. Alternatively, the second auxiliary electrode frame  125   b  may be formed by forming a conductive thin film on the phosphor layer  110  and the first auxiliary electrode frame  125   a  and patterning the conductive thin film. A phosphor layer  110  is formed on the first substrate  100 . 
     Referring to  FIG. 17B , An anode electrode  120  is formed on the first substrate  100 . The anode electrode  120  may be formed to include a projection that is in contact with the second auxiliary electrode frame  125   b . As a result, an anode area shown in  FIGS. 9A and 10A  may be formed. 
     Referring to tables in  FIGS. 18 and 19  and the following tables, effects of a field emission display device (FED) according to embodiments of the inventive concept will now be described in detail below. Values given in the tables are luminance measuring values which are obtained by applying a voltage of 10 kilovolts to an anode electrode of an FED according to each of embodiments and comparative embodiments and applying a pulse voltage of 200 volts to a gate electrode of the FED. 
     
       
         
           
               
               
               
               
               
               
             
               
                   
                   
               
               
                   
                 COM_1 
                 COM_2 
                 EMB_1 
                 EMB_2 
                 EMB_3 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Luminance 
                 5000 
                 — 
                 5650 
                 5500 
                 5650 
               
               
                 (cd/m 2 ) 
               
               
                 Luminance 
                 — 
                 — 
                 13 
                 10 
                 13 
               
               
                 Improving 
               
               
                 Rate 
               
               
                 compared to 
               
               
                 COM_1 
               
               
                 Sheet Resis- 
                 5 
                 1000 
                 5 
                 5 
                 5 
               
               
                 tance of 
               
               
                 Anode 
               
               
                 Electrode 
               
               
                 (Ω/sq) 
               
               
                   
               
               
                 (COM = Comparative Embodiment, EMB = Embodiment) 
               
            
           
         
       
     
     Referring to  FIG. 18 , a first comparative embodiment includes a first substrate  100 , an anode electrode  121  on the first substrate  100 , and a phosphor layer  110  and an anti-reflective layer  130  on the anode electrode  121 . The anode electrode  121  is a transparent electrode including indium tin oxide (ITO), and the anti-reflective layer  130  includes aluminum (Al). A second substrate  200  facing the first substrate  100  and a cathode electrode  210 , a gate electrode  220 , an insulating layer  215 , and an emitter  230  on the second substrate  200  are provided. According to the first comparative embodiment, electrons collide with phosphor of the phosphor layer  110  to emit light and the emitted light is implemented as an image by passing the anode electrode  121  and the first substrate  100 . Thus, a field emission display device (FED) according to the first comparative embodiment has lower luminance than that according to other embodiments. 
     Referring to  FIG. 19 , the second comparative embodiment includes a first substrate  100 , a phosphor layer  110  on the first substrate  100 , and an anode electrode  121  disposed on the phosphor layer  110  and including a projection protruded to the first substrate  100 . A second substrate  200  facing the first substrate  100  and a cathode electrode  210 , a gate electrode  220 , an insulating layer  215 , and an emitter  230  on the second substrate are provided. The anode electrode  121  is a metal having sheet resistance of 1000 ohms/square. According to the second comparative embodiment, arcing arises from charging because the conductivity of the anode electrode  121  is poor due to its high sheet resistance. Therefore, it was impossible to measure luminance of the second comparative embodiment. 
     The first embodiment is the luminance of a field emission display device (FED), which is measured according to the embodiments described with reference  FIGS. 3A to 4B . A first auxiliary electrode frame  125   a  and first and second electrode patterns  127   a  and  127   b  are indium tin oxide (ITO), and a second auxiliary electrode frame  125   b  is a metal containing silver (Ag) and copper (Cu) and a combination thereof. A field emission display device (FED) according to the first embodiment had improved luminance of 13 percent as compared to the first comparative embodiment and exhibited superior driving stability. 
     The second embodiment is the luminance of a field emission display device (FED), which is measured according to the embodiments described with reference to  FIGS. 6A to 8B . An auxiliary electrode frame  125  and first and second auxiliary electrode patterns  127   a  and  127   b  are a metal containing silver (Ag) and copper (Cu) and a combination thereof, and an anode electrode  120  is a metal having sheet resistance of 5 ohms/square. A field emission display device (FED) according to the second embodiment had improved luminance of 10 percent as compared to the first comparative embodiment and exhibited superior driving stability. 
     The third embodiment is the luminance of a field emission display device (FED), which is measured according to the embodiments described with reference to  FIGS. 6A to 8B . An auxiliary electrode frame  125  and first and second auxiliary electrode patterns  127   a  and  127   b  are indium tin oxide (ITO), and an anode electrode  120  is a metal having sheet resistance of 5 ohms/square. A field emission display device (FED) according to the third embodiment had improved luminance of 13 percent as compared to the first comparative embodiment and exhibited superior driving stability. 
     As explained so far, in a field emission display device (FED) according to embodiments of the inventive concept, emitted light is implemented as an image without passing an anode electrode. Thus, luminance of the FED is improved. In addition, a field emission display device (FED) according to embodiments of the inventive concept has improved adherence between an anode electrode and a phosphor layer. Thus, luminance of the FED is improved. 
     While the inventive concept has been described with reference to exemplary embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the inventive concept. Therefore, it should be understood that the above embodiments are not limiting, but illustrative.