Patent Publication Number: US-2011069091-A1

Title: Method of driving light source and display apparatus for performing the method

Description:
This application claims priority to Korean Patent Application No. 2009-89865, filed on Sep. 23 20, 2009, and all the benefits accruing therefrom under 35 U.S.C. §119, the content of which in its entirety is herein incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention relates to a method of driving a light source, and a display apparatus for performing the method. More particularly, the present invention relates to a method of driving a light source that provides substantially enhanced display quality, and a display apparatus for performing the method. 
     (2) Description of the Related Art 
     Generally, a liquid crystal display (“LCD”) apparatus includes an LCD panel, which displays an image by controlling an optical transmittance of liquid crystal molecules, and a light source module disposed below the LCD panel to provide the LCD panel with light. The LCD panel typically includes a first substrate, on which a pixel electrode and a thin-film transistor which drives the pixel electrode are disposed, and a second substrate, disposed opposite to the first substrate. A liquid crystal layer is disposed between the first substrate and the second substrate. 
     Recently, efforts have been made in attempts to develop a method of local dimming of a light source in the LCD apparatus. Specifically, in the local dimming method, amounts of light are individually controlled, according to a position thereof, to drive a light source. More specifically, in the method of local dimming of the light source, the light source is divided into a plurality of light-emitting blocks to control the amount of light of each light-emitting block of the plurality of light-emitting blocks, correspondence with dark and light areas of a display area of the LCD panel, which corresponding to the light-emitting blocks. For example, a light-emitting block corresponding to a display area that displays a black image is driven at a low luminance (e.g., is turned off), while a light-emitting block corresponding to a display area that displays a white image is driven at a relatively high luminance (e.g., is not turned off). Thus, in the method of local dimming of the light source, light transmittance of a given pixel is adjusted in accordance with a brightness of the light-emitting blocks, and power consumption may be reduced, while a contrast ratio of a displayed image may be enhanced. 
     However, in the method of local dimming of the light source, luminance levels of each of the light-emitting blocks are individually controlled, and significant display defects, such as flicker, are generated, due to a luminance level difference between adjacent light-emitting blocks, for example. Thus, there is a need to develop a display apparatus, and method of driving the same, which overcomes at least the above-mentioned deficiencies. 
     BRIEF SUMMARY OF THE INVENTION 
     Exemplary embodiments of the present invention include a method of driving a light source, in which a flickering phenomenon is substantially reduced and/or is effectively eliminated. 
     Exemplary embodiments of the present invention also provide a display apparatus for performing the method. 
     According to an exemplary embodiment of the present invention, a method of driving a light source including first through k-th light-emitting blocks (wherein ‘k’ is a natural number) is provided. The first through k-th light-emitting blocks provide a display panel with light. The method includes providing identical driving signals to a plurality of light-emitting blocks of the first through k-th light-emitting blocks on which a high gradation image, which has a gradation greater than a predetermined gradation, is displayed. 
     According to another exemplary embodiment of the present invention, there is provided a method of driving a light source including first through k-th light-emitting blocks, which provide first through k-th display blocks, respectively, of the display panel with light. The method includes driving a light-emitting block of the first through k-th light-emitting blocks on which a white image is displayed so that a luminance level of a corresponding display block on which the white image is displayed is a minimum white level. When a white image is displayed on one of the first through k-th display blocks and a black image is displayed on remaining display blocks of the first through k-th display blocks, the minimum white level is a luminance level of the corresponding display block on which the white image is displayed. 
     According to still another exemplary embodiment of the present invention, a display apparatus includes a display panel, a light source module and a light source driving part. The display panel displays an image. The light source module includes first through k-th light-emitting blocks, which provide first through k-th display blocks, respectively, of the display panel with light. The light source driving part provides identical driving signals to a plurality of light-emitting blocks of the first through k-th light-emitting blocks on which a high gradation image, which has a gradation greater than a predetermined gradation, is displayed. 
     Thus, according to exemplary embodiments of the present invention, a real luminance level of a display block that displays a white image is uniform with respect to a minimum white level, and a flickering phenomenon is thereby effectively prevented. Moreover, a luminance level is decreased during a full white driving period, and power consumption required for driving the light source is therefore substantially reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects and/or features of the present invention will become more readily apparent by describing in further detail exemplary embodiments thereof with reference to the accompanying drawings, in which: 
         FIG. 1  is an exploded perspective view of an exemplary embodiment of a display apparatus according to the present invention; 
         FIG. 2  is a block diagram of the display apparatus of  FIG. 1 ; 
         FIGS. 3A and 3B  are graphs of dimming level versus light-emitting block numbers showing luminance levels of a pattern image displayed on the display apparatus of  FIG. 1 ; 
         FIGS. 4A ,  4 B and  4 C are graphs of dimming level versus light-emitting block numbers, and duty ratios for corresponding driving signals, illustrating an exemplary embodiment of a method of driving a light source module according to the present invention; 
         FIGS. 5A ,  5 B and  5 C are graphs of dimming level versus light-emitting block numbers, and duty ratios for corresponding driving signals, illustrating another exemplary embodiment of a method of driving a light source module according to the present invention; 
         FIGS. 6A ,  6 B and  6 C are graphs of dimming level versus light-emitting block numbers, and duty ratios for corresponding driving signals, illustrating another exemplary embodiment of a method of driving a light source module according to the present invention; 
         FIGS. 7A ,  7 B and  7 C are graphs of dimming level versus light-emitting block numbers, and duty ratios for corresponding driving signals, illustrating yet another exemplary embodiment of a method of driving a light source module according to the present invention; 
         FIG. 8  is a block diagram of another exemplary embodiment of a dimming driving part according to the present invention; 
         FIG. 9  is an exploded perspective view of another exemplary embodiment of a display apparatus according to the present invention; 
         FIG. 10  is a block diagram of the display apparatus of  FIG. 9 ; 
         FIG. 11  is an exploded perspective view of still another exemplary embodiment of a display apparatus according to the present invention; and 
         FIG. 12  is a block diagram of the display apparatus of  FIG. 11 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments are shown. This invention may, however, 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 invention to those skilled in the art. Like reference numerals refer to like elements throughout. 
     It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. 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, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof. 
     Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element&#39;s relationship to another element as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in one of the figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements. The exemplary term “lower,” can therefore, encompasses both an orientation of “lower” and “upper,” depending on the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Exemplary embodiments are described herein with reference to cross section illustrations that are schematic illustrations of idealized embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present claims. 
     Hereinafter, exemplary embodiments of the present invention will be described in further detail with reference to the accompanying drawings. 
       FIG. 1  is an exploded perspective view of an exemplary embodiment of a display apparatus according to the present invention. 
     Referring to  FIG. 1 , the display apparatus includes a panel module  100  and a light source module  300 . 
     The panel module  100  includes a display panel  110 , a panel driving part  200  and a mold frame  150 . The panel driving part  200  may include a data driving part  210  and a gate driving part  230 . The data driving part  210  may include a data tape carrier package (“TCP”)  211 , on which a data driving chip is mounted, and a source circuit substrate  212  which delivers an external electric signal to the data TCP  211 . 
     The gate driving part  230  may include a gate TCP, on which a gate driving chip is mounted. Alternatively, the gate driving part  230  may be mounted on the display panel  110  in a chip type, or may be integrated into the display panel  110  during a manufacturing process thereof. 
     The mold frame  150  has a frame shape, e.g., a rectilinear shape, as shown in  FIG. 1 . A supporting surface, which supports an edge portion of the display panel  110 , is formed on the mold frame  150 . Thus, the mold frame  150  supports the display panel  110  to fix the display panel  110  therein. In additional exemplary embodiments, the mold frame  150  may be omitted. In yet another exemplary embodiment, the mold frame  150  may be replaced with a pair of side molds (not shown) that are disposed corresponding to corners of the display panel  110 . Moreover, the side molds may correspond to opposite corners of the display panel  110 , but additional exemplary embodiments are not limited thereto. 
     Still referring to  FIG. 1 , the light source module  300  includes a first light-emitting module  310 , a second light-emitting module  320 , a light guide plate  330  and a reflection plate  370 . The first light-emitting module  310  is disposed adjacent to a first edge  330   a  of the light guide plate  330 . The first light-emitting module  310  includes at least one light-emitting diode  311  and a printed circuit board  312  on which the light-emitting diode  311  (or a plurality thereof) is mounted. The second light-emitting module  320  is disposed adjacent to a second edge  330   b , opposite to the first edge  330   a , of the light guide plate  330 . A third edge  330   c  and a fourth edge  330   d , disposed opposite the third edge  330   c , connect the first edge  330   a  and the second edge  330   b  to form a periphery of the light guide plate  330 , as shown in  FIG. 1 . The second light-emitting module  320  includes at least one light-emitting diode  321  and a printed circuit board  322  on which the light-emitting diode  321  (or a plurality thereof) is mounted. 
     The light guide plate  330  guides light generated from the first light-emitting module  310  and the second light-emitting module  320  toward the display panel  110 . The reflection plate  370  is disposed between the light guide plate  330  and the receiving container  380  to reflect light that leaks from the light guide plate  330 . 
     In one or more exemplary embodiments, the light source module  300  may further include optical sheets  305  and the receiving container  380 . 
     The optical sheets  305  may include a diffusion plate  301 , a prism sheet  302  and/or a light condensing sheet  303 , as shown in  FIG. 1 , but additional exemplary embodiments are not limited thereto. The receiving container  380  receives the first light-emitting module  310  and the second light-emitting module  320 , the light guide plate  330  and the reflection plate  370 , for example. The receiving container  380  may be a bottom chassis  380 . 
     The display apparatus may further include a driving circuit substrate  700 , on which a light source driving part  600  ( FIG. 2 ) is mounted. The light source driving part  600  drives the first light-emitting module  310  and the second light-emitting module  320 . The driving circuit substrate  700  may be disposed on or near a rear surface of the receiving container  380 . 
       FIG. 2  is a block diagram of the display apparatus of  FIG. 1 . 
     Referring to  FIGS. 1 and 2 , the display apparatus includes the display panel  110 , the panel driving part  200 , the first light-emitting module  310 , the second light-emitting module  320  and the light source driving part  600 . 
     The display panel  110  includes a plurality of pixels that display images. In an exemplary embodiment, for example, a number of pixels is M×N (wherein ‘M’ and ‘N’ are natural numbers). Each of the pixels includes a switching element (not shown) connected to a corresponding gate line (not shown) and a corresponding data line (not shown), a liquid crystal capacitor (not shown) connected to the switching element, and a storage capacitor (not shown) connected to the switching element. 
     The panel driving part  200  drives the display panel  110 . Specifically, for example, the panel driving part  200  according to an exemplary embodiment includes a timing control part (not shown) that controls a driving timing of the display panel  110 , the data driving part  210 , which outputs a data voltage to the display panel  110 , and a gate driving part  230  that outputs a gate signal to the display panel  110  in synchronization with an output timing of the data driving part  210 . 
     The first light-emitting module  310  includes first through k-th light-emitting blocks B 1 , B 2 , B 3 , . . . , Bk, which provide first through k-th display blocks D 1 , D 2 , D 3 , . . . , Dk, respectively, of the display panel  110  with light. In an exemplary embodiment, ‘k’ is a natural number. Similarly, the second light-emitting module  320  includes first through k-th light-emitting blocks B 1 , B 2 , B 3 , . . . , Bk that provide the first through k-th display blocks D 1 , D 2 , D 3 , . . . , Dk, respectively, of the display panel  110  with light. 
     As shown in  FIG. 2 , the light source driving part  600  includes a dimming driving part  400  and a signal generating part  500 . The dimming driving part  400  includes a dimming level determining part  410  and a dimming correction part  420 . 
     The dimming level determining part  410  divides a frame image, received from an external source (not shown), into first through k-th image blocks corresponding to the first through k-th light-emitting blocks B 1 , B 2 , B 3 , . . . , Bk of both the first light-emitting module  310  and the second light-emitting module  320 , and obtains first through k-th representative values of the first through k-th image blocks based on gradations of each of the first through k-th image blocks. The dimming level determining part  410  determines first through k-th dimming levels based on the first through k-th representative values. The dimming level may be a duty ratio level or a luminance level. 
     The dimming correction part  420  corrects a dimming level of at least one of the first through k-th dimming levels, which is/are greater than a threshold level L_Th ( FIG. 4A ). More specifically, for example, the dimming correction part  420  corrects a dimming level of a given light-emitting block B, which provides light to a display block D in which a high gradation image, e.g., an image that has a gradation higher than a set gradation, is displayed, so that a luminance level of the display block D in which the high gradation image is displayed is set to be a minimum white level MIN_WHITE (not shown). In an exemplary embodiment, for example, the set gradation may be a gradation of no more than 240 (for an 8-bit signal). The set gradation may be set in accordance with an algorithm, for example, but additional exemplary embodiments are not limited thereto. 
     The dimming correction part  420  substantially reduces and/or effectively prevents flicker from being generated due to a luminance level difference of the display block that displays the high gradation image. Moreover, a dimming level that is greater than the threshold level L_Th is decreased to a dimming level corresponding to the minimum white level MIN_WHITE, and power consumption required for driving the light source module  300  is significantly reduced. Hereinafter, for purposes of explanation, displaying a white image will be described in further detail, but it will be noted that additional exemplary embodiments are not limited thereto. 
     In an exemplary embodiment, the dimming correction part  420  compares each of the first through k-th dimming levels with the threshold level L_Th ( FIG. 4A ), and detects a light-emitting block B having a high dimming level that is greater than the threshold level L_Th, e.g., a first light-emitting block B 1 , as shown in  FIG. 4A  (which will be described in greater detail below). The dimming correction part  420  obtains a set level in accordance with a number of the detected light-emitting blocks B and a position or positions thereof The dimming correction part  420  subtracts the set level from a maximum dimming level L_MAX to calculate a correction dimming level, and corrects a dimming level of the detected light-emitting block as the correction dimming level. A real luminance level of a light-emitting block, in which the correction dimming level is adapted, has a minimum white level MIN_WHITE, as will be described in further detail below with reference to  FIGS. 3A and 3B . 
     The signal generating part  500  generates first through k-th driving signals for driving the first through k-th light-emitting blocks B 1 , B 2 , B 3 , . . . , Bk, respectively, by using first through k-th dimming levels provided from the dimming driving part  400 . Each of the first through k-th driving signals is provided to the first light-emitting module  310  and the second light-emitting module  320 . 
     In an exemplary embodiment, the first through k-th light-emitting blocks B 1 , B 2 , B 3 , . . . , Bk are arranged in a one-dimensional structure, e.g., linearly in a single column or row (as shown in  FIG. 2 ), and the first through k-th light-emitting blocks B 1 , B 2 , B 3 , . . . , Bk are thereby driven in a one-dimensional dimming method, e.g., are driven in one column and/or in one row direction, rather than in a two-dimensional method (such as in a matrix of columns and/or rows, described below), in accordance with the first through k-th image blocks displayed on the first through k-th display blocks D 1 , D 2 , D 3 , . . . , Dk. 
       FIGS. 3A and 3B  are graphs of dimming level versus light-emitting block numbers showing luminance levels of a pattern image displayed on the display apparatus of  FIG. 1 . 
     Referring to  FIG. 3A , a pattern image PI is displayed on the display panel  110 . The pattern image PI displays a white image (indicated by the unshaded portion) on the first display block D 1 , and displays a black image (indicated by the shaded portions) on a second display block D 2 , a third display block D 3 , a fourth display block D 4 , a fifth display block D 5 , a sixth display block D 6 , a seventh display block D 7  and an eighth display block D 8 . 
     The first through eighth light-emitting blocks B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B 7  and B 8 , corresponding to the first through eighth display blocks D 1 , D 2 , D 3 , D 4 , D 5 , D 6 , D 7  and D 8 , respectively, have corresponding dimming levels shown in  FIG. 3B , in accordance with the pattern image PI of  FIG. 3A . Specifically, the first light-emitting block B 1 , corresponding to the first display block D 1 , emits light based on a first dimming level L 1  having the maximum dimming level L_MAX, and the second through eighth light-emitting blocks B 2 , B 3 , B 4 , B 5 , B 6 , B 7  and B 8  corresponding to the remaining second through eighth display blocks D 2 , D 3 , D 4 , D 5 , D 6 , D 7  and D 8  emit light based on second through eighth dimming levels L 2 , L 3 , L 4 , L 5 , L 6 , L 7  and L 8 , respectively, which gradually decrease with respect to the maximum dimming level L_MAX. Thus, a real luminance level of a white image displayed on the first display block D 1  is determined by luminance levels of the first light-emitting block B 1  and the second through eighth light-emitting blocks B 2 , B 3 , B 4 , B 5 , B 6 , B 7  and B 8  adjacent to the first light-emitting block B 1 . 
     Thus, when a white image is displayed on one display block B, a real luminance level of the white image displayed on the display block B may be defined as the minimum white level MIN_WHITE. The minimum white level MIN_WHITE may be set in accordance with an algorithm, but additional exemplary embodiments are not limited thereto. 
     The dimming correction part  420  may be implemented using a logic circuit or, alternatively, a look-up table, but additional exemplary embodiments are not limited thereto. For example, in an additional exemplary embodiment, the dimming correction part  420  may be implemented using the logic circuit together with the look-up table. A plurality of set levels may be stored in the look-up table, described in greater below with reference to Table 1, in accordance with the number of light-emitting blocks B having a dimming level higher than the threshold level L_Th, and a position of the light-emitting blocks B in the display panel  110 . For example, when a number of the light-emitting blocks is k, a number of the set levels may be 2 k . 
     Table 1 illustrates an exemplary embodiment of a lookup table having 256 (=2 8 ) addresses when the number of light-emitting blocks is eight, e.g., k is equal to eight (8). 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Address 
                 Set Level 
                 Address 
                 Set Level 
               
               
                   
                   
               
             
            
               
                   
                 00000000 
                 None 
                 . . . 
                 . . . 
               
               
                   
                 00000001 
                 None 
                 00010000 
                 None 
               
               
                   
                 00000010 
                 None 
                 . . . 
                 . . . 
               
               
                   
                 00000011 
                 B 
                 00111100 
                 J 
               
               
                   
                 . . . 
                 . . . 
                 . . . 
                 . . . 
               
               
                   
                 00000111 
                 G 
                 11111111 
                 P 
               
               
                   
                   
               
            
           
         
       
     
     Referring to Table 1, each of the first through eighth light-emitting blocks B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B 7  and B 8  corresponds to first through eighth dimming levels. A bit value of the address may be obtained by comparing the first through eighth dimming levels with the threshold level L_Th. More particularly, the bit value of the address is “1” when the first through eighth dimming levels are greater than the threshold level L_Th, and the bit value of the address is “0” when the first through eighth dimming levels are less than the threshold level L_Th. Specifically, for example, when the address is “00000011,” the first and second dimming levels of the first and second light-emitting blocks B 1  and B 2  are greater than the threshold level L_Th, and the set level is “B.” Thus, a value, in which the set level “B” is subtracted from the maximum dimming level L_MAX, may be determined as a correction dimming level of the first and second light-emitting blocks B 1  and B 2 , as will be described in greater detail below. In an exemplary embodiment, “B,” “G,” “J” and “P” are natural numbers. 
     According to Table 1, when the address is “00000000,” the set level does not exist. Specifically, when the first through eighth dimming levels are less than the threshold level L_Th, a white image is not displayed on the display panel  110 , and it is not necessary to correct the first through eighth dimming levels. Moreover, when one of the first through eighth dimming levels is greater than the threshold level L_Th, e.g., when one of the bits of the address is “1” (e.g., “00000001,” “00000010,” “00010000,” etc.), a real luminance level of the white image displayed on the display panel  110  is the minimum white level MN_WHITE and it is not necessary to correct the first through eighth dimming levels. 
       FIGS. 4A ,  4 B and  4 C are graphs of dimming level versus light-emitting block numbers, and duty ratios for corresponding driving signals, illustrating an exemplary embodiment of a method of driving a light source module according to the present invention. 
     Referring to  FIGS. 2 and 4A , the dimming level determining part  410  determines first through eighth dimming levels L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7  and L 8  of the first through eighth light-emitting blocks B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B 7  and B 8  of the dimming level determining part  410 . As shown in  FIG. 4A , a first dimming level L 1  has the maximum dimming level L_MAX, and the remaining second through eighth dimming levels L 2 , L 3 , L 4 , L 5 , L 6 , L 7  and L 8  gradually decrease with respect to the maximum dimming level L_MAX. Put another way, in  FIG. 4A , only the first dimming level L 1  is only greater than the threshold level L_Th. 
     When one of the first through eighth dimming levels L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7  and L 8  is greater than the threshold level L_Th, a real luminance level of the white image displayed on the display panel  110  may have the minimum white level MIN_WHITE. 
     Referring to  FIG. 4B , only the first dimming level L 1  is greater than the threshold level L_Th, and the dimming correction part  420  thereby determines that a real luminance level of the image displayed on the display panel  110  is the minimum white level MIN_WHITE. The dimming correction part  420  determines that the first dimming level L 1  is a correction dimming level L 1  of the first light-emitting block B 1 . Thus, the dimming correction part  420  provides the signal generating part  500  with first through eighth correction dimming levels L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7  and L 8 . 
     Referring to  FIG. 4C , the signal generating part  500  generates first through eighth driving signals S 1 , S 2 , S 3 , . . . , S 8  based on the first through eighth correction dimming levels L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7  and L 8 . A first duty ratio DR 1  of the first driving signal S 1  has a maximum duty ratio DR_MAX based on the maximum dimming level L_MAX. The second through eighth driving signals S 2 , S 3 , S 4 , S 5 , S 6 , S 7  and S 8  have second through eighth duty ratios DR 2 , DR 3 , DR 4 , DR 5 , DR 6 , DR 7  and DR 8 , respectively. 
       FIGS. 5A ,  5 B and  5 C are graphs of dimming level versus light-emitting block numbers, and duty ratios for corresponding driving signals, illustrating another exemplary embodiment of a method of driving a light source module according to the present invention. 
     Referring to  FIGS. 2 and 5A , the dimming level determining part  410  determines first through eighth dimming levels L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7  and L 8  of the first through eighth light-emitting blocks B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B 7  and B 8 . As shown in  FIG. 5A , the first and second dimming levels L 1  and L 2  are greater than the threshold level L_Th, and the remaining third through eighth dimming levels L 3 , L 4 , L 5 , L 6 , L 7  and L 8  are less than the threshold level L_Th. 
     Referring to  FIG. 5B , the dimming correction part  420  corrects the first and second dimming levels L 1  and L 2  so that a real luminance level of an image displayed on the first and second display blocks D 1  and D 2 , corresponding to the first and second dimming levels L 1  and L 2  that are greater than the threshold levels L_Th, is the minimum white level MN_WHITE. For example, referring to the look-up table shown in Table 1, a set level for correcting the first and second dimming levels L 1  and L 2  may be “B.” 
     The dimming correction part  420  obtains the set level “B” by using the look-up table, and then subtracts the set level “B” from the maximum dimming level L_MAX to determine a correction dimming level L_B of the first and second dimming levels L 1  and L 2 . The dimming correction part  420  does not correct the third through eighth dimming levels L 3 , L 4 , L 5 , L 6 , L 7  and L 8  that are less than the threshold level L_Th. 
     The dimming correction part  420  provides the signal generating part  500  with the correction dimming level L_B and the third through eighth dimming levels L 3 , L 4 , L 5 , L 6 , L 7  and L 8 . 
     Referring to  FIG. 5C , the signal generating part  500  generates first and second driving signals S 1  and S 2  based on the correction dimming level L_B. Each of the first and second driving signals S 1  and S 2  has a duty ratio DRB corresponding to the correction dimming level L_B. The signal generating part  500  generates third through eighth driving signals S 3 , S 4 , S 5 , S 6 , S 7  and S 8  based on the third through eighth dimming level L 3 , L 4 , L 5 , L 6 , L 7  and L 8 . The third through eighth driving signals S 3 , S 4 , S 5 , S 6 , S 7  and S 8  have duty ratio DR 3 , DR 4 , DR 5 , DR 6 , DR 7  and DR 8 , respectively as shown in  FIG. 5C . 
     Consequently, the first and second light-emitting blocks B 1  and B 2  are operated by, e.g., are driven by, an identical driving signal, and thus a real luminance level of the first and second display blocks D 1  and D 2  that receive light from the first and second light-emitting blocks B 1  and B 2 , respectively, is the minimum white level MIN_WHITE. 
       FIGS. 6A ,  6 B and  6 C are graphs of dimming level versus light-emitting block numbers, and duty ratios for corresponding driving signals, illustrating another exemplary embodiment of a method of driving a light source module according to the present invention. 
     Referring to  FIGS. 2 and 6A , the dimming level determining part  410  determines first through eighth dimming levels L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7  and L 8  of the first through eighth light-emitting blocks B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B 7  and B 8 . As shown in  FIG. 6A , the first, second and third dimming levels L 1 , L 2  and L 3  are greater than the threshold level L_Th, and the remaining fourth through eighth dimming levels L 4 , L 5 , L 6 , L 7  and L 8  are less than the threshold level L_Th. 
     Referring to  FIG. 6B , the dimming correction part  420  corrects the first, second and third dimming levels L 1 , L 2  and L 3  so that a real luminance level of an image displayed on the first, second and third display blocks D 1 , D 2  and D 3 , corresponding to the first, second and third dimming levels L 1 , L 2  and L 3 , respectively, that are greater than the threshold levels L_Th, is the minimum white level MIN_WHITE. For example, referring to the look-up table of Table 1, a set level for correcting the first, second and third dimming levels L 1 , L 2  and L 3  may be “G.” 
     The dimming correction part  420  obtains the set level “G” by using the look-up table, and then subtracts the set level “G” from the maximum dimming level L_MAX to determine a correction dimming level L_G of the first, second and third dimming levels L 1 , L 2  and L 3 . The dimming correction part  420  does not correct the fourth through eighth dimming levels L 4 , L 5 , L 6 , L 7  and L 8  that are less than the threshold level L_Th. 
     The dimming correction part  420  provides the signal generating part  500  with the correction dimming level L_G and the fourth through eighth dimming levels L 4 , L 5 , L 6 , L 7  and L 8 . 
     Referring to  FIG. 6C , the signal generating part  500  generates first, second and third driving signals S 1 , S 2  and S 3  based on the correction dimming level L_G. The first, second and third driving signals S 1 , S 2  and S 3  each have a duty ratio DR_G corresponding to the correction dimming level L_G The signal generating part  500  generates fourth through eighth driving signals S 4 , S 5 , S 6 , S 7  and S 8  based on the fourth through eighth dimming level L 4 , L 5 , L 6 , L 7  and L 8 , respectively. The fourth through eighth driving signals S 4 , S 5 , S 6 , S 7  and S 8  have fourth through eighth duty ratios DR 4 , DR 5 , DR 6 , DR 7  and DR 8 , respectively. 
     Consequently, the first, second and third light-emitting blocks B 1 , B 2  and B 3  are operated by, e.g., are driven by, an identical driving signal, and thus a real luminance level of the first, second and third display blocks D 1 , D 2  and D 3  that receive light from the first, second and third light-emitting blocks B 1 , B 2  and B 3  may be the minimum white level MN_WHITE. 
       FIGS. 7A ,  7 B and  7 C are graphs of dimming level versus light-emitting block numbers, and duty ratios for corresponding driving signals, illustrating yet another exemplary embodiment of a method of driving a light source module according to the present invention. 
     Referring to  FIGS. 2 and 7A , the dimming level determining part  410  determines first through eighth dimming levels L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7  and L 8  of first through eighth light-emitting blocks B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B 7  and B 8 . All of the first through eighth dimming levels L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7  and L 8  are greater than the threshold level L_Th. When the display panel  110  is driven in a full white mode, all of the first through eighth dimming levels L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7  and L 8  have the maximum dimming level L_MAX. 
     When the first through eighth light-emitting blocks B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B 7  and B 8  are driven using the maximum dimming level L_MAX, a real luminance level of the display panel  110  has the maximum luminance level MAX_WHITE that is greater than the minimum white level MN_WHITE. Each of the first through eighth light-emitting blocks B 1 , B 2 , B 3 , . . . , B 8  may be influenced by a luminance level of adjacent light-emitting blocks B, and thus luminance levels of the adjacent light-emitting blocks B may be accumulated so that the display panel  110  may have the maximum white level MAX_WHITE that is greater than the minimum white level MIN_WHITE. 
     Referring to  FIG. 7B , the dimming correction part  420  corrects a real dimming luminance level of the display panel  110  driving in the full white mode into the minimum white level MN_WHITE by correcting the first through eighth dimming levels L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7  and L 8  having the maximum dimming level L_MAX. Specifically, referring to Table 1, for example, the dimming correction part  420  obtains a set level “P” corresponding to the address “11111111.” 
     The dimming correction part  420  subtracts the set level “P” from the maximum dimming level L_MAX to determine a correction dimming level L_P of the first through eighth light-emitting blocks B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B 7  and B 8 . 
     The dimming correction part  420  provides the signal generating part  500  with the correction dimming level L_P. 
     Referring to  FIG. 7C , the signal generating part  500  generates first through eighth driving signals S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , S 7  and S 8  based on the correction dimming level L_P. Each of the first through eighth driving signals S 1 , S 2 , S 3 , B 4 , B 5 , B 6 , B 7  and S 8  has a duty ratio DR_P corresponding to the correction dimming level L_P. 
     Consequently, the first through eighth light-emitting blocks B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B 7  and B 8  are operated by, e.g., are driven by, an identical driving signal, and thus a real luminance level of the display panel  110  receiving lights from the first through eighth light-emitting blocks B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B 7  and B 8  may be the minimum white level MN_WHITE. 
     Therefore, the real luminance level of the white image displayed on the display panel  110  is uniformed to the minimum white level MN_WHITE, and flicker due to a luminance level difference of the white image is substantially reduced and/or is effectively prevented. Moreover, when the display panel  110  is driven in the full white mode, power consumption required for driving the light source module  300  is significantly reduced. 
       FIG. 8  is a block diagram of another exemplary embodiment of a dimming driving part according to the present invention. The display apparatus according to the exemplary embodiment shown in  FIG. 8  is substantially the same as the display apparatus described in greater above with reference to  FIGS. 1 through 7C , except for a dimming driving part  400 A. Thus, the same reference characters are used in  FIG. 8  to refer to same or like components as those shown in  FIGS. 1 through 7C , and any repetitive detailed description thereof will hereinafter be omitted. 
     Referring to  FIGS. 2 and 8 , the dimming driving part  400 A includes a dimming level determining part  410 , a dimming correction part  420  and a gradation correction part  430 . 
     The dimming level determining part  410  obtains first through k-th representative values of the first through k-th image blocks D 1 , D 2 , D 3 , . . . , Dk corresponding to the first through k-th light-emitting blocks B 1 , B 2 , B 3 , . . . , Bk by using a frame image received from an external source (not shown). In an exemplary embodiment, ‘k’ is a natural number. The dimming level determining part  410  determines first through k-th dimming levels based on the first through k-th representative values. The dimming level may be a duty ratio level or a luminance level, but additional exemplary embodiments are not limited thereto. 
     The dimming correction part  420  corrects a dimming level or levels of the first through k-th dimming levels, which is/are greater than a threshold level L_Th, so that a real luminance level of a light-emitting block B corresponding to the dimming level or levels greater than the threshold level L_Th is the minimum white level MIN_WHITE. Thus, the dimming correction part  420  effectively prevents flicker from being generated due to a luminance level difference of the white image displayed on the display panel  110 . Moreover, a dimming level that is greater than the threshold level L_Th is decreased, and power consumption required for driving the light source module  300  is substantially reduced. 
     The gradation correction part  430  corrects a gradation of a frame image based on the dimming levels that are corrected by the dimming correction part  420 . The gradation correction part  430  corrects gradations of the first image block displayed on the first display block D 1  by using a first dimming level, and corrects gradations of the second image block displayed on the second display block D 2  by using a second dimming level. Similarly as to described in greater detail above, the gradation correction part  430  corrects gradations of the third through k-th image blocks by using third through k-th dimming levels. For example, when the first light-emitting block B 1  emits light having a high luminance, the gradation correction part  430  corrects a gradation of the first image block corresponding to the first light-emitting block B 1 . Likewise, the gradation correction part  430  controls a gradation voltage level of the display panel  110  in accordance with a luminance level of the light source module  300 , and power consumption required for driving the display panel  110  is significantly reduced. 
     In an exemplary embodiment, a method of driving a light source shown in  FIG. 8  is substantially the same as described in greater detail above with reference to  FIGS. 4A through 7C , and thus any repetitive detailed description thereof will hereinafter be omitted. 
       FIG. 9  is an exploded perspective view of another exemplary embodiment of a display apparatus according to the present invention.  FIG. 10  is a block diagram of the display apparatus of  FIG. 9 . Hereinafter, the same reference characters in  FIGS. 9 and 12  will be used to refer to the same or like components described in greater detail above, and thus any repetitive detailed explanation will simplified or omitted. 
     Referring to  FIGS. 9 and 10 , the display apparatus according to an exemplary embodiment includes a panel module  100  and a light source module  300 A. 
     The panel module  100  includes a display panel  110 , a panel driving part  200  and a mold frame  150 . The panel driving part  200  may include a data driving part  210  and a gate driving part  230  ( FIG. 1 ). 
     The panel driving part  200  drives the display panel  110 . Specifically, for example, the panel driving part  200  includes a timing control part (not shown) that controls a driving timing of the display panel  110 , the data driving part  210  that outputs a data voltage to the display panel  110  and the gate driving part  230  that outputs a gate signal to the display panel  110  in synchronization with an output timing of the data driving part  210 . 
     The light source module  300 A includes a plurality of lamps  340 , a reflection plate  370  and a receiving container  380 . Lamps  340  of the plurality of lamps  340  are arranged on, e.g., are disposed on, the reflection plate  370  and generate light. The reflection plate  370  is disposed on a lower surface, e.g., a bottom surface, of the receiving container  380  to reflect the light generated from the lamps  340 . In one or more exemplary embodiments, the light source module  300  may further include a plurality of optical sheets  305 . 
     The light source module  300 A is divided into first through k-th light-emitting blocks B 1 , B 2 , B 3 , . . . , Bk corresponding to the lamps  340 . Each of the light-emitting blocks includes at least one lamp  340 . The first through k-th light emitting blocks B 1 , B 2 , B 3 , . . . , Bk provide the first through k-th display blocks D 1 , D 2 , D 3 , . . . , Dk with light. 
     The light source driving part  600  includes a dimming driving part  400  and a signal generating part  500 . The dimming driving part  400  includes a dimming level determining part  410  and a dimming correction part  420 . 
     The dimming level determining part  410  obtains first through k-th representative values of the first through k-th image blocks corresponding to first through k-th light-emitting blocks B 1 , B 2 , B 3 , . . . , Bk (wherein ‘k’ is a natural number). The dimming level determining part  410  determines first through k-th dimming levels based on the first through k-th representative values. The dimming level may be a duty ratio level or a luminance level, but additional exemplary embodiments are not limited thereto. 
     The dimming correction part  420  corrects a dimming level that is greater than a threshold level L_Th of the first through k-th dimming levels. For example, the dimming correction part  420  may correct a dimming level of a light-emitting block B, which provides light to a display block D in which a white image that has a greater gradation than a set gradation is displayed, so that a luminance level of the display block B on which the white image is displayed is to a minimum white level MIN_WHITE. Accordingly, the dimming correction part  420  effectively prevents flicker from being generated due to a luminance level difference of the white image displayed on the display panel  110 . Moreover, a dimming level that is greater than the threshold level L_Th is decreased, so that power consumption required for driving the light source module  300  is substantially reduced. 
     The signal generating part  500  generates first through k-th driving signals for driving the first through k-th light-emitting blocks B 1 , B 2 , B 3 , . . . , Bk by using first through k-th dimming levels provided from the dimming driving part  400 . 
     Consequently, the first through k-th light-emitting blocks B 1 , B 2 , B 3 , . . . , Bk are driven in a one-dimensional dimming method, e.g., are driven in one column and/or in one row, rather than in a two-dimensional method (such as in a matrix of columns and/or rows), in accordance with the first through k-th image blocks displayed on the first through k-th display blocks D 1 , D 2 , D 3 , . . . , Dk. 
     Moreover, the light source driving part  600  may include a dimming driving part  400 A including a gradation correction part  430 , as shown in  FIG. 8 . 
     A method of driving the light source shown in  FIGS. 9 and 10  is substantially the same as described in greater detail above with reference to  FIGS. 4A through 7C , and thus any repetitive detailed explanation will hereinafter be omitted. 
       FIG. 11  is an exploded perspective view of yet another exemplary embodiment of a display apparatus according to the present invention.  FIG. 12  is a block diagram of the display apparatus of  FIG. 11 . Hereinafter, the same reference characters in  FIGS. 11  and  12  refer to the same or like components described in greater detail above, and thus any repetitive detailed explanation will be simplified or omitted. 
     Referring to  FIGS. 11 and 12 , the display apparatus according to an exemplary embodiment includes a panel module  100  and a light source module  300 B. 
     The panel module  100  includes a display panel  110 , a panel driving part  200  and a mold frame  150 . The panel driving part  200  may include a data driving part  210  and a gate driving part  230  ( FIG. 1 ). 
     The panel driving part  200  drives the display panel  110 . Specifically, for example, the panel driving part  200  includes a timing control part (not shown) that controls a driving timing of the display panel  110 , the data driving part  210  that outputs a data voltage to the display panel  110  and the gate driving part  230  that outputs a gate signal to the display panel  110  in synchronization with an output timing of the data driving part  210 . 
     The light source module  300 B includes a light-emitting module  350  and a receiving container  380 . The light-emitting module  350  includes a printed circuit board (“PCB”)  351  and a plurality of light-emitting diodes  353  mounted on, e.g., disposed on, the printed circuit board  351 . The printed circuit board  351  is disposed on a lower, e.g., bottom, surface of the receiving container  380 . The printed circuit board  351  may include a plurality of printed circuit boards. In an exemplary embodiment, the light source module  300  may further include a plurality of optical sheets  305 . 
     The light source module  300 B divides light-emitting diodes  353  into first through (i×j)-th light-emitting blocks B 1 , B 2 , B 3 , . . . , B(i×j). Each of the light-emitting blocks includes at least one light-emitting diode  353 . The first through (i×j)-th light-emitting blocks B 1 , B 2 , B 3 , . . . , B(i×j) individually provide first through (i×j)-th display blocks D 1 , D 2 , D 3 , . . . , D(i×j) of the display panel  110  with light. In an exemplary embodiment, ‘i’ and ‘j’ are natural numbers. 
     The light source driving part  600  includes a dimming driving part  400  and a signal generating part  500 . The dimming driving part  400  includes a dimming level determining part  410  and a dimming correction part  420 . 
     The dimming level determining part  410  obtains first through (i×j)-th representative values of the first through (i×j)-th image blocks corresponding to the first through (i×j)-th light-emitting blocks B 1 , B 2 , B 3 , . . . , B(i×j). The dimming level determining part  410  determines first through (i×j)-th dimming levels based on the first through (i×j)-th representative values. The dimming level may be a duty ratio level or a luminance level, but is not particularly limited thereto. 
     The dimming correction part  420  corrects a dimming level that is greater than a threshold level L_Th of the first through (i×j)-th dimming levels. Thus, the dimming correction part  420  corrects a dimming level of a light-emitting block B that provides light to a display block D in which a white image that has a higher gradation than a predetermined gradation is displayed, so that a luminance level of the display block D that displays the white image is a minimum white level MIN_WHITE. When a white image is displayed on one display block D of first through (i×j)-th display blocks D 1 , D 2 , D 3 , . . . , D(i×j) and a black image is displayed on the remaining display blocks D, the minimum white level may be a real luminance level of the white image displayed on the display panel  110 . Moreover, the minimum white level MIN_WHITE may be set in accordance with an algorithm, but additional exemplary embodiments are not limited thereto. 
     The dimming correction part  420  may be implemented using a logic circuit or in a look-up table. Alternatively, the dimming correction part  420  may be implemented using the logic circuit together with the look-up table. A plurality of set levels may be stored in the look-up table in accordance with the number of light-emitting blocks B having a dimming level higher than the threshold level L_Th and a position of the light-emitting blocks B in the display panel  110 . For example, when a number of the light-emitting blocks B is (i×j), a number of the set levels may be 2 (i×j) . 
     In an exemplary embodiment, the dimming correction part  420  effectively prevents flicker from being generated due to a luminance level difference of the white image display on the display panel  110 . In addition, a dimming level that is greater than the threshold level L_Th is decreased, so that power consumption required for driving the light source module  300 B is substantially reduced. 
     The signal generating part  500  generates first through (i×j)-th driving signals for driving the first through (i×j)-th light-emitting blocks B 1 , B 2 , B 3 , . . . , B(i×j) by using the first through (i×j)-th dimming levels provided from the dimming driving part  400 . 
     Consequently, the first through (i×j)-th light-emitting blocks B 1 , B 2 , B 3 , . . . , B(i×j) may be driven in a two-dimensional dimming method, e.g., may be driven in a matrix method, in accordance with first through (i×j)-th image blocks displayed on the first through (i×j)-th display blocks D 1 , D 2 , D 3 , . . . , D(i×j). 
     A method of driving the light source shown in  FIGS. 11 and 12  is substantially the same as described above with reference to  FIGS. 4A to 7C , and thus any repetitive detailed description will hereinafter be omitted. 
     In an exemplary embodiment, the light source driving part  600  may include a dimming driving part  400 A including the gradation correction part  430 , as shown in  FIG. 8 . For example, the gradation correction part  430  may correct a gradation of the first through (i×j)-th image blocks by using the first through (i×j)-th dimming levels that are corrected by the dimming correction part  420 . 
     The present invention should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the present invention to those skilled in the art. 
     While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit or scope of the present invention as defined by the following claims.