Abstract:
The present invention relates to a transparent electronic display board that is capable of uniform optical output and, more particularly, to a transparent electronic display board that is capable of uniform optical output wherein the pattern width and length are adjusted according to the sheet resistance of a transparent electrode of the transparent electronic display board, wherein a driving voltage applied to a light-emitting device can be uniformly supplied within a constant range, and wherein multiple light sources disposed in the transparent electronic display board can emit light at uniform intensity.

Description:
BACKGROUND 
       [0001]    1. Field 
         [0002]    The present invention generally relates to a transparent electronic display board capable of producing a uniform optical output. More particularly, the present invention relates to a transparent electronic display board capable of producing a uniform optical output, in which a driving voltage applied to a light-emitting element can be uniformly supplied within a constant range by adjusting the width and length of patterns according to the sheet resistance of a transparent electrode, so that multiple light sources installed in the transparent electronic display board can emit light at uniform intensity, thus producing a uniform optical output. 
         [0003]    2. Description of the Related Art 
         [0004]    Generally, an electronic display board using neon, a cold cathode lamp (CCL), or a light emitting diode (LED) is widely used as an outdoor light-emitting device. Also, an external electrode fluorescent lamp (EEFL), a cold cathode fluorescent lamp (CCFL), a light-emitting diode electronic display board, or the like is used as an indoor light-emitting device. 
         [0005]    In this case, neon or a cold cathode lamp is disadvantageous because it consumes excessive power due to the use of high-voltage power, has the risks of electric shock and fire, and has a short lifespan. Also, an EEEL or a CCFL is disadvantageous because outdoor use is difficult due to the high frequency use, and because it has low illuminance and a short lifespan. 
         [0006]    Also, an electronic display board using an LED is characterized in that it emits light only in one direction because the back of the light emitting surface is blocked by a cover plate due to the processing of an electric wire or a black membrane. 
         [0007]    On the other hand, contemporary light-emitting devices are being used as advertising boards rather than merely just for lighting, or are widely used for interior decoration design wherein an aesthetic sense is added. 
         [0008]    However, the aforementioned light emitting devices have a limitation in assigning an aesthetic sense due to constraints such as the size of the lamp and the size of the stand or the like supporting such a light-emitting device. 
         [0009]    Consequently, in the past, to assign the above-described aesthetic sense to a light-emitting device, a transparent electronic display board was released, in which multiple light-emitting elements were attached to a transparent electrode and were configured to emit light using a controller, thus displaying characters or figures on the transparent electrode, and also representing videos. In the transparent electronic display board, multiple light-emitting elements form connectivity patterns on a transparent electrode. Typically, as the light-emitting elements, light-emitting elements having a two-electrode structure, a three-electrode structure, and a four-electrode structure were used. A view of connectivity patterns of a transparent electronic display board to which four-electrode light-emitting elements are applied, among conventional transparent electronic display boards, is illustrated in  FIG. 1 . 
         [0010]    Illustrated in  FIG. 1  is an exemplary view of the connectivity patterns for conventional transparent electronic display boards using four-electrode light-emitting elements. 
         [0011]    Referring to  FIG. 1 , the conventional transparent electronic display board includes multiple light-emitting elements  1  fixedly bonded by transparent resin between two transparent electrodes  2  disposed opposite each other; connectivity patterns  2   a  to  2   d  of the transparent electrodes, connected to any one electrode of each light-emitting element  1  via a coating on the transparent electrode  2 ; and conductive tape  2   a′  to  2   d′  configured to guide power to the connectivity patterns  2   a  to  2   d  of the transparent electrodes. 
         [0012]    The multiple light-emitting elements  1  are four-electrode light-emitting elements  1 , in which one cathode electrode and three anode electrodes are formed, and the electrodes are respectively connected to connectivity patterns  2   a  to  2   d  extending from different transparent electrode conductive tapes. Here, the multiple light-emitting elements  1  are vertically arranged in a line, and multiple lines in which the light-emitting elements  1  are vertically aligned are formed. 
         [0013]    The connectivity patterns  2   a  to  2   d  are extended from the transparent electrode conductive tape, and are respectively connected to the anode electrodes and cathode electrode of the corresponding four-electrode light-emitting element  1 . Here, the connectivity patterns  2   a  to  2   d  have separate shapes insulated from each other so that they are not in contact with each other. 
         [0014]    Further, the connectivity patterns  2   a  to  2   d  have shapes extending from both ends to the light-emitting elements  1  sequentially aligned in a center portion. That is, to function as a ground terminal, the first connectivity pattern  2   a  connected to the cathode electrode and the second to fourth connectivity patterns  2   b  to  2   d  connected to the anode electrodes are sequentially connected. Behind the fourth connectivity pattern  2   d , fifth to seventh connectivity patterns  2   e  to  2   g  connected to anode electrodes are extended again. Here, the first connectivity pattern  2   a  connected to the cathode electrode is formed again subsequently to the seventh connectivity pattern  2   g  connected to an anode electrode. 
         [0015]    Therefore, the conventional transparent electronic display board is problematic because a connectivity pattern connected to the cathode electrode of the light-emitting element and used as a ground terminal, is set according to the number of light-emitting elements aligned in a vertical or horizontal direction, meaning, man-hours are added in the manufacturing process, thus increasing manufacturing costs and deteriorating productivity. 
         [0016]    Further, since the conventional transparent electronic display board has different light-emitting element locations, extended lengths of the connectivity patterns connected to the electrodes of the respective light-emitting elements are different from each other, but the widths thereof are identical to each other. 
         [0017]    Since the conventional transparent electronic display board has the sheet resistance of the transparent electrode itself and resistance per unit area of each connectivity pattern, the range of voltage loss differs depending on the widths and lengths of the connectivity patterns, so that a drive voltage applied to a light-emitting element connected at the location where the length of a connectivity pattern is extended as the longest length is different from a drive voltage applied to a light-emitting element connected at the location where the length of the connectivity pattern is the shortest. 
         [0018]    Accordingly, the conventional transparent electronic display board is problematic in that, as drive voltages falling within different ranges are applied to respective light-emitting elements fixed at different locations, and are used to drive the light-emitting elements, non-uniform light is output at different intensities, thus making it difficult to implement clear image quality upon displaying images or videos. 
         [0019]    The present invention has been made keeping in mind the above problems, and one aspect of the present invention is to provide a transparent electronic display board, in which the widths of connectivity patterns required to supply power to light-emitting elements in the transparent electronic display board are selectively formed in consideration of the sheet resistance and length of each transparent electrode, thus enabling all light-emitting elements to exhibit a uniform optical output. 
       SUMMARY 
       [0020]    In one embodiment, the present invention provides a transparent electronic display board capable of producing a uniform optical output, which compensates for the loss of voltages depending on resistances by increasing the widths of connectivity patterns as the lengths thereof become larger, wherein the connectivity patterns are connected to transparent electrodes for applying power of one or more light-emitting elements, which are fixed on at least one surface of a pair of transparent plates spaced apart from each other and bonded by transparent resin loaded therebetween, and which emit light using applied power. 
         [0021]    The present invention is advantageous because the widths of connectivity patterns connected to light-emitting elements are selectively formed so that the loss of power caused by the sheet resistance and length of transparent electrodes can be compensated for, so that all light-emitting elements installed in a transparent electronic display board have a uniform optical output, thus realizing precise images and videos, and providing a screen having a clear image quality. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a plan view showing a conventional transparent electronic display board. 
           [0023]      FIGS. 2 and 3  are diagrams showing a transparent electronic display board capable of producing a uniform optical output according to one embodiment of the present invention. 
           [0024]      FIG. 4  is an enlarged view showing a light-emitting element in the transparent electronic display board capable of producing a uniform optical output according to one embodiment of the present invention. 
           [0025]      FIG. 5  is a diagram showing a first comparative example of the transparent electronic display board capable of producing a uniform optical output according to one embodiment of the present invention. 
           [0026]      FIG. 6  is a diagram showing a first experimental example of the transparent electronic display board capable of producing a uniform optical output according to one embodiment of the present invention. 
           [0027]      FIG. 7  is a diagram showing a second comparative example of the transparent electronic display board capable of producing a uniform optical output according to one embodiment of the present invention. 
           [0028]      FIG. 8  is diagram showing a second experimental example of the transparent electronic display board capable of producing a uniform optical output according to one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    The present invention includes the following embodiments. 
         [0030]    In one embodiment, a transparent electronic display board capable of producing a uniform optical output according to the present invention includes one or more light-emitting elements fixed on at least one surface of a pair of transparent plates bonded to each other so that the transparent plates are spaced apart from each other by transparent resin; transparent electrodes formed by applying a conductive material to a corresponding transparent plate and configured to apply power of the one or more light-emitting elements; and connectivity patterns etched from each transparent electrode and connected to respective electrodes of the light-emitting elements at different lengths so that electrical signals are transferred to the light-emitting elements, wherein widths of the connectivity patterns are increased as the lengths of the connectivity patterns connected to the light-emitting elements are increased. 
         [0031]    In another embodiment of the present invention, the widths of the connectivity patterns may be calculated using the following Equations 1 and 2: 
         [0000]        L  (mm)/ W  (mm)×sheet resistance of transparent electrode (Ω)=resistance of etched area (Ω)   Equation 1
 
         [0000]      rated voltage ( V )/resistance of etched area (kΩ)= I  (mA)   Equation 2
 
         [0000]    where L denotes a length of a connectivity pattern; W denotes a width of the connectivity pattern; ‘sheet resistance of transparent electrode’ denotes self-sheet resistance of the transparent electrode; ‘rated voltage’ denotes a voltage applied to the transparent electronic display board; I denotes a current value applied from the connectivity pattern to the corresponding light-emitting element (hereinafter referred to as a ‘drive current for the light-emitting element’); and ‘resistance of etched area’ denotes a resistance value per unit area of the connectivity pattern formed by etching the transparent electrode. 
         [0032]    In a further embodiment of the present invention, each light-emitting element may include one or more anode electrodes to which the connectivity patterns are connected, and one cathode electrode, and the connectivity patterns may include one or more anode connectivity patterns etched from the transparent electrode and connected to the anode electrodes; and a single cathode connectivity pattern connected in common to cathode electrodes respectively formed in the multiple light-emitting elements. 
         [0033]    In yet another embodiment of the present invention, connection terminals at which the cathode connectivity pattern and the anode connectivity patterns are sequentially extended from at least one of upper/lower and left/right ends of the transparent plate and are connected to transparent conductive tape may be aligned, a connection terminal of the cathode connectivity pattern may be formed in an uppermost portion of the connection terminals, and connection terminals of the one or more anode connectivity patterns may be sequentially extended below the connection terminal of the cathode connectivity pattern. 
         [0034]    In still another embodiment of the present invention, the anode connectivity patterns may be respectively connected to the one or more anode electrodes of the light-emitting element, and one or more of the anode connectivity patterns may be spaced apart from each other with the cathode connectivity pattern interposed therebetween and are connected to the anode electrodes. 
         [0035]    In still another embodiment of the present invention, one or more light-emitting elements may be aligned in a horizontal or vertical direction, and a number of anode connectivity patterns identical to a number of anode electrodes of each light-emitting element may be extended for each light-emitting element. 
         [0036]    Hereinafter, other embodiments of the present invention will be described in detail with the attached drawings. 
         [0037]      FIGS. 2 and 3  are diagrams showing a transparent electronic display board capable of producing a uniform optical output according to one embodiment of the present invention, and  FIG. 4  is an enlarged view showing a light-emitting element in the transparent electronic display board capable of producing a uniform optical output according to one embodiment of the present invention. 
         [0038]    Referring to  FIGS. 2 to 4 , the transparent electronic display board according to one embodiment of the present invention includes a pair of transparent plates  10  that are spaced apart from each other and are bonded to each other by transparent resin; transparent electrodes  21  to  24  formed on one surface of any one of the paired transparent plates  10  and are made of a conductive material to guide power; multiple light-emitting elements  20 ,  20 ′,  20 ″, and  20 ″′ fixed on any one of the paired transparent plates  10  and configured to emit light using power applied through the transparent electrodes  21  to  24 ; a controller  30  configured to control ON/OFF operations of the light-emitting elements  20 ,  20 ′,  20 ″, and  20 ′″; and transparent electrode conductive tape  25  configured to supply power to the transparent electrodes  21  to  24 . 
         [0039]    The transparent plates  10  are configured such that two transparent plates  10  are mutually opposite each other and are bonded to each other with transparent resin loaded between the plates. The transparent plates  10  may be manufactured using any one of a glass plate, an acrylic plate, and a polycarbonate plate, all of which are made of a transparent material. Since the coupling between the transparent plates  10  and the light-emitting elements  20  is a well-known technology, a separate illustration and a detailed description thereof will be omitted. 
         [0040]    The light-emitting elements  20  are luminous bodies turned on or off depending on the supply of power, and are configured such that multiple light-emitting elements are fixed by conductive resin (not shown) in the transparent electrodes  21 ,  22 , and  23  formed on one surface of any one of the paired transparent plates  10 . Here, the lower portions of the light-emitting elements  20  are fixed at the transparent electrodes  21 ,  22 , and  23 , and the upper portions of the light-emitting elements are protected by transparent resin and are bonded to other transparent electrodes. Here, in each light-emitting element  20 , anodes  20   a  to  20   c  and a cathode electrode  20   d  are formed, and the anode electrodes  20   a ,  20   b , and  20   c  cause positive power to be input or output, and the cathode electrode  20   d  causes negative power to be input or output. 
         [0041]    Further, the light-emitting element 20 may be implemented using any one of a two-electrode light-emitting element in which one anode electrode  20   a  to  20   c  and one cathode electrode  20   d  are formed, a three-electrode light-emitting element in which two anode electrodes and one cathode electrode are formed, and a fourth-electrode light-emitting element  20  in which three anode electrodes and one cathode electrode are formed. As an example of the present invention, a description will be made using the four-electrode light-emitting element. 
         [0042]    Each of the transparent electrodes  21  to  24  is formed such that any one of an indium tim oxide (ITO), an indium zinc oxide (IZO), and liquid polymer, which are conductive materials, is applied to one surface opposite the other of the paired transparent plates. Each of the transparent electrodes  21  to  24  is partitioned and divided into multiple sections to be insulated from each other so that the multiple sections are respectively connected to the anode electrodes  20   a ,  20   b , and  20   c  and the cathode electrode  20   d  of the light-emitting element  20 , and then one or more connectivity patterns  21  to  24  are formed to be extended to electrically communicate signals to the light-emitting element. 
         [0043]    Here, each of the transparent electrodes  21  to  24  is partitioned into sections such that the sections are respectively connected to the anode electrodes  20   a ,  20   b , and  20   c  and the cathode electrode  20   d  of the light-emitting element  20 , and are configured to transfer a control signal applied from the controller  30  to the light-emitting element  20 . A description will be made on the assumption that areas which are partitioned from each transparent electrode  21  to  24  to be connected to the anode electrodes  20   a ,  20   b , and  20   c  and the cathode electrode  20   d  of the light-emitting element are designated as anode connectivity patterns  21  to  23  and the cathode connectivity pattern  24 , respectively. 
         [0044]    More specifically, the connectivity patterns of the transparent electrodes  21 ,  22 ,  23 , and  24  include multiple groups, each including one or more anode connectivity patterns  21  to  23  respectively connected to the anode electrodes  20   a ,  20   b , and  20   c  formed in a single light-emitting element  20  and one cathode connectivity pattern  24  connected to the cathode electrode  20   d.    
         [0045]    The number of anode connectivity patterns  21  to  23  that are formed is identical to the number of anode electrodes  20   a ,  20   b , and  20   c  of each light-emitting element  20 , but there is a single cathode connectivity pattern  24  that is connected in common to the cathode electrodes  20   d  of the multiple light-emitting elements  20 . 
         [0046]    In the transparent electrodes  21  to  24 , multiple groups  21  to  23 , each having first to third anode connectivity patterns  211  to  213  respectively connected to the first to third anode electrodes  20   a ,  20   b , and  20   c  in, for example, the four-electrode light-emitting element  20 , are formed. 
         [0047]    For example, the first group  21  of the anode connectivity patterns includes a first anode connectivity pattern  211  connected to the first anode electrode  20   a  of the first light-emitting element  20 , a second anode connectivity pattern  212  connected to the second anode electrode  20   b , and a third anode connectivity pattern  213  connected to the third anode electrode  20   c.    
         [0048]    Similarly, the second group  22  and the third group  23  of anode connectivity patterns include first to third anode connectivity patterns  221 ,  222 , and  223  and first to third anode connectivity patterns  231 ,  232 , and  233  connected to the anodes of the second light-emitting element  20 ′ and the third light-emitting element  20 ″, respectively. 
         [0049]    However, the cathode connectivity pattern  24  is a common pattern, which is connected in common to the cathode electrodes  20   d  respectively formed on the multiple light-emitting elements  20 . 
         [0050]    That is, one embodiment of the present invention is configured such that one cathode connectivity pattern  24  is connected in common to the cathode electrodes  20   d  of the multiple light-emitting elements  20  installed on the transparent electronic display board, and such that the anode connectivity patterns  21  to  23  are respectively formed on the anode electrodes  20   a ,  20   b , and  20   c  of the multiple light-emitting elements  20 . 
         [0051]    In this regard, the groups  21  to  23  of the anode connectivity patterns are connected to respective light-emitting elements that extend from the end of one side of the transparent plate  10  to the other side thereof and that are aligned in a transverse direction. In this case, the individual groups  21  to  23  of anode connectivity patterns are extended at different lengths depending on the locations of the respective light-emitting elements  20 ,  20 ′, and  20 ″, and the widths of the anode connectivity patterns  21  to  23  are differently set in consideration of the lengths of anode connectivity patterns and the resistances per unit area of the anode connectivity patterns. 
         [0052]    One reason for this is to maintain uniform intensities of light emitted from all light-emitting elements, installed on the entire transparent electronic display board. A detailed description thereof will be made later. 
         [0053]    Further, the transparent electrode conductive tape  25  are respectively attached to the connection terminals of the anode connectivity patterns  21  to  23 . Yet further, the transparent electrode conductive tape  25  are bonded to the start points of the anode connectivity patterns  21  to  23 . 
         [0054]    That is, in the transparent electronic display board, connection terminals  26  are aligned wherein the cathode connectivity pattern  24  and the individual groups  21  to  23  of the anode connectivity patterns are sequentially extended from at least one of upper/lower and left/right ends of the transparent plate  10  and are connected to the transparent conductive tape  25 . 
         [0055]    The connection terminals  26  are configured such that a connection terminal to be connected to the cathode connectivity pattern  24  is formed in an uppermost portion, and connection terminals  26  of the anode connectivity patterns  211  to  233 , corresponding to the groups  21  to  23  respectively connected to the one or more anodes, are sequentially extended and formed below the connection terminal of the cathode connection pattern  24 . 
         [0056]    In addition, respective anode connectivity patterns  211  to  233  included in the groups  21  to  23  are connected to one or more anode electrodes in the light-emitting elements  20 ,  20 ′, and  20 ″, and one or more of the anode connectivity patterns are spaced apart from each other with the cathode connectivity pattern  24  interposed therebetween, and are connected to the anode electrodes  20   a  to  20   c  (e.g., see the second anode connectivity pattern  212  and the third anode connectivity pattern  213  of  FIG. 4 ). 
         [0057]    Further, the respective anode connectivity patterns  211  to  233  of the groups  21  to  23  are extended from the transparent electrode conductive tapes  25  and are connected to the anode electrodes  20   a ,  20   b , and  20   c  of different light-emitting elements  20 . Here, the cathode connectivity pattern  24  corresponds to the remaining area other than an area in which the anode connectivity patterns  211  to  233  are formed. 
         [0058]    Furthermore, in order to solve conventional problems (supra) wherein the intensities of optical outputs of the respective light-emitting element  20 ,  20 ′, and  20 ″ are not uniform due to the differences in the lengths of the anode connectivity patterns  211  to  233  and in the self-resistances thereof per unit area, the present invention sequentially increases the widths of the anode connectivity patterns  211  to  233  connected to the anode electrodes of the light-emitting elements  20 ,  20 ′, and  20 ″ depending on the sheet resistances and lengths of the connectivity patterns. This will be described in detail later. 
         [0059]      FIG. 5  is a diagram showing a first comparative example of the transparent electronic display board capable of producing a uniform optical output according to one embodiment of the present invention, and  FIG. 6  is a diagram showing a first experimental example of the transparent electronic display board capable of producing a uniform optical output according to one embodiment of the present invention. 
         [0060]    The first comparative example and the first experimental example include anode connectivity patterns  211  to  233  and  211 ′ to  233 ′ of the first to third groups  210  to  230  and  210 ′ to  230 ′ so that the connectivity patterns are connected to the first to third light-emitting elements  20 ,  20 ′, and  20 ″, respectively. The first to third groups  210  to  230  denote the groups  21  to  23  of anode connectivity patterns connected to the above-described light-emitting elements, and are each shown as being formed as, for example, a single pattern, in  FIGS. 5 and 6 . 
         [0061]    Also, in the attached  FIGS. 5 and 6 , first to third light-emitting elements connected to the ends of the first to third anode connectivity patterns are not illustrated. 
         [0062]    Each of the first experimental example and the first comparative example includes a first group  210 ′ or  210  connected to the first light-emitting element  20 , a second group  220 ′ or  220  connected to the second light-emitting element  20 ′, and a third group  230  or  230 ′ connected to the third light-emitting element  20 ″, and extended lengths L 1 , L 2 , and L 3  for respective groups are different from each other. 
         [0063]    Further, the first experimental example was set such that the widths of the anode connectivity patterns  211  to  233  of the respective groups  210  to  230  were sequentially increased depending on the extended lengths, and the first comparative example was set such that the widths of the anode connectivity patterns  211 ′ to  233 ′ were identical to each other regardless of the extended lengths. 
         [0064]    Here, the light-emitting element  20  is configured such that coupling terminals  210   a ,  210   a′ ,  210   b ,  210   b ′,  210   c , and  210   c ′, which are formed to be horizontally bent at the ends of the respective anode connectivity patterns  211  to  233  and  211 ′ to  233 ′ corresponding to the first to third groups  210 ,  210 ′  220 ,  220 ′,  230 , and  230 ′, are bonded to the one or more electrodes  20   a  to  20   c  respectively formed in the light-emitting elements  20 ,  20 ′, and  20 ″. 
         [0065]    From the first experimental example and the first comparative example, current values applied to the light-emitting elements  20 ,  20 ′, and  20 ″ were measured at the coupling terminals  210   a ,  210   a ′,  210   b ,  210   b ′,  210   c , and  210   c ′, and variations in the current values with an increase in the widths of the patterns along the lengths of the patterns were measured and compared. The current values are calculated using the following Equations 1 and 2: 
         [0000]        L  (mm)/ W  (mm)×sheet resistance of transparent electrode (Ω)=resistance of etched area (Ω)   Equation 1
 
         [0000]        V /resistance of etched area (kΩ)= I  (mA)   Equation 2
 
         [0000]    where L denotes the length of each anode connectivity pattern; W denotes the width of the anode connectivity pattern; ‘sheet resistance of transparent electrode’ denotes self-sheet resistance of the transparent electrode; V denotes a rated voltage; I denotes a current value applied from the anode connectivity pattern to the corresponding light-emitting element (hereinafter referred to as a ‘drive current for the light-emitting element’); and ‘resistance of etched area’ denotes a resistance value per unit area of the anode connectivity pattern formed by etching the transparent electrode. 
         [0066]    The sheet resistance value of the transparent electrode may have deviations depending on, for example, different manufacturing companies and product specifications, and products most widely used typically use a resistance of 14Ω. 
         [0067]    Therefore, the present invention may maintain drive currents applied to the first to third light-emitting elements  20 ,  20 ′ and  20 ″ by adjusting the widths or lengths of the anode connectivity patterns at uniform levels falling within a predetermined range, thus enabling the first to third light-emitting elements  20 ,  20 ′, and  20 ″ to output a uniform quantity of light. 
         [0068]    As described above, the present invention may adjust drive current values applied to the light-emitting elements  20 ,  20 ′, and  20 ″ by adjusting the widths of the anode connectivity patterns  211  to  233 , or may also adjust the drive currents of the light-emitting elements by adjusting the lengths of the anode connectivity patterns other than the widths thereof, depending on the application/needs of a designer or a user. The setting of uniform drive current values by adjusting the widths or lengths of the anode connectivity patterns corresponds to any one of various modifications falling within the scope of the technical spirit of the present invention. 
         [0069]    Below, the operations and effects implemented by the technical spirit of the above-described present invention will be described by comparing experimental data required to prove uniform output of drive current values depending on the widths of the anode connectivity patterns with conventional drive current values. 
         [0070]    Table 1 shows data obtained by measuring drive currents in the first comparative example. Here, a rated voltage was 12 V, and products of the same specification having a reference current of 5 mA were used as the first to third light-emitting elements  20 ,  20 ′, and  20 ″. 
         [0071]    As the drive currents, applied currents were measured at coupling terminals connected to the electrodes of the light-emitting elements  20 ,  20 ′, and  20 ″, a sheet resistance of the transparent electrode was set to 14Ω, the rated voltage was set to 12 V, and then the same voltage was applied to all of the anode connectivity patterns. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                 First etched 
                 First 
                 Second etched 
                   
               
               
                 Connectivity 
                 area resistance 
                 drive 
                 area resistance 
                 Second drive 
               
               
                 pattern 
                 (theoretical 
                 current 
                 (measured value, 
                 current 
               
               
                 No. 
                 value, kΩ) 
                 (mA) 
                 kΩ) 
                 (mA) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 0.76 
                 15.79 
                 0.71 
                 13.31 
               
               
                 2 
                 3.57 
                 3.36 
                 3.77 
                 2.77 
               
               
                 3 
                 6.39 
                 1.88 
                 6.85 
                 1.56 
               
               
                   
               
             
          
         
       
     
         [0072]    The first drive currents denote current values that are calculated using the resistances of a first etched area checked via the specifications of products and that are measured at the coupling terminals  210   a ′ to  230   a ′ of respective anode connectivity patterns of first to third groups  210 ′ to  230 ′, and the second drive currents denote values that are actually measured at the coupling terminals  210   a ′ to  230   a ′ of the connectivity patterns of the first to third groups  210 ′ to  230 ′. 
         [0073]    In this case, for the anode connectivity patterns  211 ′ to  233 ′ of the first to third groups  210 ′ to  230 ′, the lengths of the anode connectivity patterns  211 ′ to  213 ′ of the first group  210 ′ are extended to the shortest length, and the anode connectivity patterns  231 ′ to  233 ′ of the third group  230 ′ are extended to the longest length, but the widths of the patterns are equal to each other. 
         [0074]    Under such a condition, it can be seen that a variation of a maximum of 12 mA occurs in currents measured at the coupling terminals  210   a ′ to  230   a ′ depending on the lengths of the anode connectivity patterns. 
         [0075]    Table 2 shows data obtained by respectively measuring drive currents in the first experimental example. Here, the lengths L 1 , L 2 , and L 3  of the anode connectivity patterns in the first experimental example are identical to the lengths L 1 , L 2 , and L 3  in the first comparative example, but the widths of the patterns are widened as the lengths are increased. The experimental condition was set such that a rated voltage was 12 V, and the reference current value of each light-emitting element was 5 mA, and thus a product having the same specification as that of the first comparative example was used. 
         [0076]    Further, the width of each anode connectivity pattern  211  to  213  of the first group  210  was 0.5 mm, the width of each anode connectivity pattern  221  to  223  of the second group  220  was 2.5 mm, and the width of each anode connectivity pattern  231  to  233  of the third group  230  was 4 mm. The widths of the anode connectivity patterns were increased as the lengths L 1 , L 2 , and L 3  of the anode connectivity patterns were extended. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                   
                 First etched 
                   
                 Second etched 
                   
               
               
                   
                 area 
                   
                 area 
               
               
                 Connectivity 
                 resistance 
                 First drive 
                 resistance 
                 Second drive 
               
               
                 pattern 
                 (theoretical 
                 current 
                 (measured 
                 current 
               
               
                 No. 
                 value, kΩ) 
                 (mA) 
                 value, kΩ) 
                 (mA) 
               
               
                   
               
             
             
               
                 1 
                 1.42 
                 8.45 
                 1.28 
                 6.80 
               
               
                 2 
                 1.44 
                 8.33 
                 1.28 
                 6.83 
               
               
                 3 
                 1.64 
                 7.32 
                 1.46 
                 6.00 
               
               
                   
               
             
          
         
       
     
         [0077]    When the drive current values shown in Table 2 were checked, deviations between values of a first drive current and a second drive current measured at the coupling terminal  210   a  of the anode connectivity patterns  211  to  213  of the first group  210  and at the coupling terminal  230   a  of the anode connectivity patterns  231  to  233  of the third group  230  did not exceed a maximum of 1.2 mA. 
         [0078]    That is, drive currents, which are measured at the coupling terminals  210   a  to  230   a  of the anode connectivity patterns for respective groups  210  to  230  and are applied to the light-emitting elements  20 ,  20 ′, and  20 ″, are increased as the widths of the anode connectivity patterns are increased, so that it can be seen that, unlike the data of Table 1, the loss of current depending on the lengths of the anode connectivity patterns  211  to  233  is compensated for. 
         [0079]    Further, the present applicant compared a second comparative example in which the widths of anode connectivity patterns are uniform with a second experimental example in which the widths of anode connectivity patterns are sequentially increased, via a transparent electronic display board to which four-electrode light-emitting elements designed to configure a total of four anode connectivity patterns in each group are applied. 
         [0080]      FIG. 7  is a diagram showing a second comparative example of the transparent electronic display board capable of producing a uniform optical output according to one embodiment of the present invention, and  FIG. 8  is a second experimental example of the transparent electronic display board capable of producing a uniform optical output according to one embodiment of the present invention. 
         [0081]    Referring to  FIG. 7 , the second comparative example includes one or more groups  21  to  23  having one or more anode connectivity patterns  211  to  233  that are formed as patterns by etching transparent electrodes  21  to  24 , which are formed by applying a conductive material to one surface of the transparent plate  10 ; and one or more light-emitting elements  20 ,  20 ′, and  20 ″ for emitting light using power applied from the anode connectivity patterns  211  to  233 . 
         [0082]    Here, the light-emitting elements  20 ,  20 ′, and  20 ″ are described using four-electrode light-emitting elements by way of example, and as described above, the cathode electrodes of the respective light-emitting elements are connected to each other via a cathode connectivity pattern  24 . 
         [0083]    The respective groups  210 ′ to  230 ′, in which one or more anode connectivity patterns  211 ′ to  233 ′ are included, have lengths that are sequentially increased for the respective groups, and the first to third anode connectivity patterns  211 ′ to  233 ′ of the respective groups  210 ′ to  230 ′ are connected to the anode electrodes of the light-emitting elements  20 ,  20 ′, and  20 ″. 
         [0084]    The respective anode connectivity patterns  211 ′ to  233 ′ of the first to third groups  210 ′ to  230 ′ have the same width of 1 mm, and the lengths thereof are gradually increased in the sequence of the first to third groups  210 ′ to  230 ′. In the first group  210 ′, first to third anode connectivity patterns  211 ′ to  213 ′ connected to the respective electrodes of the first light-emitting element  20  are formed. In the second group  220 ′, forth to sixth anode connectivity patterns  221 ′ to  223 ′ connected to the respective electrodes of the second light-emitting element  20 ′ are formed. In the third group  230 ′, seventh to ninth anode connectivity patterns  231 ′ to  233 ′ connected to the respective electrodes of the third light-emitting element  20 ″ are formed. Here, the widths of the first to ninth anode connectivity patterns  211 ′ to  233 ′ are identical, and the lengths thereof differ for the respective groups. Measured data for the second comparative example is given in Table 3. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                   
                 First etched 
                   
                 Second etched 
                   
               
               
                   
                 area 
                   
                 area 
               
               
                   
                 resistance 
                 First drive 
                 resistance 
                 Second drive 
               
               
                 Connectivity 
                 (theoretical 
                 current 
                 (measured 
                 current 
               
               
                 pattern No. 
                 value, kΩ) 
                 (mA) 
                 value, kΩ) 
                 (mA) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 0.77 
                 15.58 
                 0.72 
                 13.43 
               
               
                 2 
                 0.78 
                 15.38 
                 0.74 
                 12.03 
               
               
                 3 
                 0.83 
                 14.36 
                 0.80 
                 11.46 
               
               
                 4 
                 3.66 
                 3.28 
                 3.83 
                 2.73 
               
               
                 5 
                 3.66 
                 3.28 
                 3.86 
                 2.51 
               
               
                 6 
                 3.71 
                 3.23 
                 3.92 
                 2.43 
               
               
                 7 
                 6.54 
                 1.83 
                 7.02 
                 1.48 
               
               
                 8 
                 6.55 
                 1.83 
                 7.01 
                 1.36 
               
               
                 9 
                 6.60 
                 1.82 
                 7.06 
                 1.37 
               
               
                   
               
             
          
         
       
     
         [0085]    A rated voltage was 12 V, a reference current was 5 mA, and the sheet resistance of each transparent electrode was 14Ω. The drive currents were measured for respective anode connectivity patterns. 
         [0086]    Referring to Table 3, as the length of the pattern is extended, the resistance value of the etched area is increased up to a maximum of 5.9 kΩ, and a deviation of a maximum of 13.75 mA occurs in the drive current. That is, in the second comparative example, the quantity of light output from the light-emitting elements  20 ,  20 ′, and  20 ″ differs depending on whether the pattern is long or short, so that the optical output of the entire transparent electronic display board is not uniform, thus leading to the conclusion that it is difficult to implement a precise video. 
         [0087]    To be compared with the experimental results of the second comparative example, experiments on the second experimental example of the present invention shown in  FIG. 8  were conducted under the same experimental conditions, and the drive currents such as those in the following Table 4 were measured. 
         [0088]    Here, the second experimental example of the present invention was configured such that the lengths of anode connectivity patterns and the rated voltage of the second comparative example, and the light-emitting elements and transparent electrodes having the same specification as those of the second comparative example were used, except that the widths of the anode connectivity patterns of the first to third groups  210  to  230  were sequentially increased. 
         [0089]    The respective widths of the first to third anode connectivity patterns  211  to  213  of the first group  210  were set to 0.5 mm, the respective widths of the anode connectivity patterns  221  to  223  of the second group  220  were set to 2.5 mm, and the respective widths of the anode connectivity patterns  231  to  233  of the third group  230  were set to 4 mm. The lengths L 1 , L 2 , and L 3  of the connectivity patterns were identical to those of the above-described second comparative example, the sheet resistance of the transparent electrode was set to 14Ω, and the rated voltage was 12 V. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                   
                 First etched 
                   
                 Second etched 
                   
               
               
                   
                 area 
                   
                 area 
               
               
                   
                 resistance 
                 First drive 
                 resistance 
                 Second drive 
               
               
                 Pattern 
                 (theoretical 
                 current 
                 (measured 
                 current 
               
               
                 No. 
                 value, kΩ) 
                 (mA) 
                 value, kΩ) 
                 (mA) 
               
               
                   
               
             
             
               
                 1 
                 1.39 
                 8.63 
                 1.22 
                 6.92 
               
               
                 2 
                 1.44 
                 8.33 
                 1.31 
                 5.86 
               
               
                 3 
                 1.52 
                 7.89 
                 1.37 
                 5.52 
               
               
                 4 
                 1.56 
                 7.70 
                 1.36 
                 6.41 
               
               
                 5 
                 1.55 
                 7.74 
                 1.37 
                 5.76 
               
               
                 6 
                 1.61 
                 7.45 
                 1.42 
                 5.49 
               
               
                 7 
                 1.87 
                 6.42 
                 1.76 
                 5.16 
               
               
                 8 
                 1.90 
                 6.31 
                 1.69 
                 4.56 
               
               
                 9 
                 1.98 
                 6.06 
                 1.58 
                 4.49 
               
               
                   
               
             
          
         
       
     
         [0090]    In Table 4, the first drive current, which is a theoretical current value checked via the specification of products, was calculated using the above-described Equations 1 and 2, and the second drive current is actually measured data. Further, the widths of the anode connectivity patterns  211  to  233  of the first to third groups  210  to  230  were calculated by utilizing Equations 1 and 2. 
         [0091]    The first drive current value and the second drive current value have a maximum deviation of 2.53 mA, which is measured as a value much smaller than a deviation of 13.76 mA of the second comparative example. Therefore, in the present invention, the deviation between the optical outputs of all light-emitting elements  20 ,  20 ′, and  20 ″ is small regardless of the lengths of the anode connectivity patterns  211  to  233 , and thus the entire transparent electronic display board may output uniform light. 
         [0092]    In this way, multiple light-emitting elements installed on the transparent electronic display board emit light at uniform optical output, thus enabling an image and a video to be implemented with more precise and clearer image quality. 
         [0093]    Although detailed embodiments of the present invention have been disclosed, those skilled in the art will appreciate that various modifications and changes are possible without departing from the technical spirit of the invention, and those modifications and changes belong to the scope of the accompanying claims. 
         [0094]    The present invention may correct optical outputs of multiple light-emitting elements installed on a transparent electronic display board to be uniform, so that videos having clearer image quality may be provided using the transparent electronic display board, thus enabling the transparent electronic display board to be potentially utilized for any number of applications including, without limitation, an information provision terminal for advertising, indoor/outdoor interior designs, and wired/wireless communication devices.