Abstract:
A method of driving liquid crystal display panel includes generating a plurality of eye data frames from a received frame of image data. A high data frame having a first liquid crystal rotating attribute and a low data frame having a lesser second liquid crystal rotating attribute are respectively generated from a respective two of the generated plurality of eye data frames. The high data frame and the low data frame are alternatingly used to drive the liquid crystal display panel according to a time division rate such that liquid crystal molecules are subjected to low and higher crystal rotating forces. In one embodiment, each pixel is space-divided into first and second sub areas having different distances between the first and second pixel electrodes, and the high data and the low data are time-divided and displayed on the pixel, enhancing visibility of the resulting image for different viewing angles.

Description:
PRIORITY STATEMENT 
     This application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 2010-87415, filed on Sep. 7, 2010 in the Korean Intellectual Property Office (KIPO), the contents of which are herein incorporated by reference in their entireties. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     Embodiments of the present invention relate generally to flat panel displays. More specifically, embodiments of the present invention relate to methods for driving a liquid crystal display panel, and liquid crystal display apparatuses for performing the methods. 
     2. Description of the Related Art 
     A liquid crystal display (LCD) is a display apparatus typically having two glass substrates and a liquid crystal disposed between the glass substrates. The liquid crystal is an intermediate matter between a solid and a liquid. The LCD changes an arrangement of the liquid crystal molecules according to a voltage difference, so as to generate images. However, the LCD commonly has relatively slow response speed, low resolution and narrow viewing-angle, which are disadvantages. 
     Recently, demand for displays capable of producing three-dimensional (3-D) images has increased. Accordingly, demand has risen for 3-D capable LCDs. A 3-D image is commonly displayed using a binocular parallax principle through both eyes. For example, in a liquid crystal shutter stereoscopic type display apparatus, a viewer wears a pair of glasses which sequentially open and close a left eye liquid crystal shutter and a right eye liquid crystal shutter in synchronization with the display of left and right eye frame images. This LCD is typically driven based on a progressive scan method, which produces crosstalk due to a difference between grayscales of two images while changing from a left eye image (or a right eye image) to the right eye image (or the left eye image). This crosstalk decreases the display quality. Thus, a black image is inserted between the left eye image and the right eye image, typically with a driving frequency of 240 Hz, so as to prevent crosstalk and enhance display quality. 
     SUMMARY OF THE INVENTION 
     Example embodiments of the present invention provide methods for driving a liquid crystal display (LCD) panel with improved visibility. 
     Example embodiments of the present invention also provide an LCD apparatus performing the methods. 
     According to one aspect of the present invention, there is provided a method of driving an LCD panel. In the method, a plurality of data frames is generated from a data frame. A high data frame having a high luminance and a low data frame having a low luminance are generated two of the data frames. The high data frame and the low data frame are displayed on the LCD panel according to a time division rate. 
     According to one aspect of the present invention, an LCD apparatus includes an LCD panel, a frame rate controller, a data generator and a panel driver. The LCD panel includes a plurality of pixels. The frame rate controller generates a plurality of data frames from a data frame. The data generator generates a high data frame having a high luminance and a low data frame having a low luminance from two of the data frames. The panel driver displays the high data frame and the low data frame on the LCD panel according to a time division rate. 
     According to the present invention, the high data and the low data are time-divided and are displayed on the pixel, and thus a visibility may be enhanced. In addition, the high data and the low data are time-divided and are displayed on the pixel space-divided into first and second subareas in which distances between first and second pixel electrodes are different from each other, and thus the visibility may be further enhanced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features and advantages of the present invention will become more apparent by describing in detail the preferred embodiments thereof with reference to the accompanying drawings, in which: 
         FIG. 1  is a plan view illustrating a liquid crystal display apparatus according to an example embodiment of the present invention; 
         FIG. 2A  is a block diagram illustrating a data generator in  FIG. 1 ; 
         FIG. 2B  is a gamma curve adjusted to the data generator in  FIG. 2A ; 
         FIG. 3  is a plan view illustrating a liquid crystal display panel in  FIG. 11 ; 
         FIG. 4  is an equivalent circuit diagram of the liquid crystal display panel in  FIG. 3 ; 
         FIG. 5A  is a graph showing visibility according to a distance between first and second pixel electrodes in  FIG. 3 ; 
         FIG. 5B  is a graph showing a V-T curve according to the distance between the first and second electrodes in  FIG. 3 ; 
         FIG. 5C  is a graph showing a rising time and a falling according to the distance between the first and second electrodes in  FIG. 3 ; 
         FIG. 6  is a conceptual diagram explaining a method of displaying a tree-dimensional (3-D) image using the liquid crystal display apparatus in  FIG. 1 ; 
         FIG. 7  is a conceptual diagram explaining a method of displaying a two-dimensional (2-D) image using the liquid crystal display apparatus in  FIG. 1 ; 
         FIG. 8A  is a graph showing a visibility of the image of a liquid crystal display apparatus according to a comparative example embodiment; 
         FIG. 8B  is a graph showing visibility of the 2-D image time-divided by the liquid crystal display apparatus in  FIG. 1 ; and 
         FIG. 8C  is a graph showing visibility of the 3-D image time-divided by the liquid crystal display apparatus in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, the present invention will be explained in detail with reference to the accompanying drawings. Measured numerical quantities, ranges, ratios and the like are approximate, and the invention includes other quantities, ranges, ratios, etc. besides only those listed. 
       FIG. 1  is a plan view illustrating a liquid crystal display (LCD) apparatus according to an example embodiment of the present invention.  FIG. 2A  is a block diagram illustrating a data generator in  FIG. 1 .  FIG. 2B  is a gamma curve adjusted to the data generator in  FIG. 2A . 
     Referring to  FIG. 1 , the LCD apparatus includes a mode decider  210 , a frame rate controller  230 , a timing controller  250 , a data generator  270 , a panel driver  300  and an LCD panel  400 . 
     The mode decider  210  decides an image mode of received data. The mode decider  210  decides the image mode of the received data according to a received synchronizing signal, a mode information signal, or the like, or decides the image mode of the received data according to a mode signal selected by a user. For example, the mode decider  210  decides whether the received data are two-dimensional (2-D) image modes or three-dimensional (3-D) image modes. The frame rate controller  230 , the timing controller  250  and the data generator  270  are driven according to the image mode decided by the mode decider  210 . 
     The frame rate controller (FRC)  230  generates a plurality of “eye” data frames from the received data (e.g., frames specific to one or the other of the user&#39;s eyes). An eye data frame is defined as image data within a frame unit. A frame unit includes an application of alternating polarities as shall be made clearer when  FIG. 4  is described. 
     When the received data are in 3-D image mode, the frame rate controller  230  divides the received data into left eye data and right eye data, and scales the left eye data and the right eye data to the data frames corresponding to a resolution of the LCD panel  400 , repeating the scaled left and right eye data L and R, and generates N, (N is M/2 and a natural number, and M is not less than 8 and a natural number) left eye data frames and N right eye data frames so that, in total, M data frames are generated. When the received data are in 2-D image mode, the frame rate controller  230  generates (N−1) data frames using the present data frame and a following frame, and doubles the present data frame and (N−1) data frames to generate a total of M data frames. 
     The timing controller  250  provides the data frames generated by the frame rate controller  230  to the data generator  270 . When the received data are 3-D image mode data, the timing controller  250  inserts a black data frame between the left eye data frame and the right eye data frame. For example, the timing controller  250  sequentially outputs (N−1) left eye data frames, a left eye black data frame, (N−1) right eye data frames and a right eye black data frame. When the received data are in 2-D image mode, the timing controller  250  provides the M data frames to the data generator  270  without alternation. 
     Referring to  FIGS. 2A and 2B , the data generator  270  generates a high data frame or a low data frame from each of the M data frames according to image mode and a preset time-division rate based on the image mode, and outputs the high data frame or the low data frame. 
     The data generator  270  includes first and second data tables  271  and  272  that correspond to different levels of DL voltages applied in the circuit of  FIG. 4  for subjecting the liquid crystals to correspondingly opposed polarities and different drive voltages. High data corresponding to input data are stored in the first data table  271 . A high gamma curve HG, which for a given desired luminance value (T 1 —can be any horizontal line) calls for a high data line drive voltage (V 1 H) disposed on one side of a reference voltage (V 1 R) for realizing that same luminance (T 1 ) when using a predetermined reference gamma curve RG, is applied for the high data. Low data corresponding to the input data are stored in the second data table  272 . The low gamma curve LG, which for a given desired luminance value (T 1 ) calls for a lower data line drive voltage (V 1 L) disposed on an opposed side of the reference voltage (V 1 R) for that same luminance (T 1 ) when using the predetermined reference gamma curve RG, is applied for the low data. The data generator  270  converts each of the M data frames to be high data or low data using the first and second data tables  271  and  272  with a time-division rate which is preset as I:J (each of I and J is no less than 1 and is also a natural number) on the high data frame and the low data frame according to the image mode. In other words, the data generator  270  receives image frames, and applies either a high gamma curve or a low gamma curve to the image, so as to either boost or lower the inducement of rotation of liquid crystals so as to achieve a desired image luminance (e.g., T 1 ), the combination of boosted and lowered inducements being relative to a static reference luminance-achieving value (V 1 R) and thus respectively adjust for a desired combination of high and low liquid crystal rotation rates (for viscous liquid crystals) as shall be made clearer when  FIG. 5C  is described below. Here, the terms “high” and “low” are relative terms referring to an applied gamma curve higher or lower, respectively, than a reference gamma curve RG (which can be any suitable predetermined gamma curve for the corresponding LCD panel). The present disclosure of invention contemplates any numerical values of the high and low gamma curves HG, LG. Similarly, the present disclosure of invention contemplates any luminance values (T) resulting from the utilized combinations of high and low data frames. 
     For example, when an LCD apparatus has a frame frequency of 480 Hz and the received data are in 3-D image mode, the data generator  270  generates one left eye high data frame and two left eye low data frames from three left data frames of the four left eye data frames except for the black frame data according to a time-division rate that is preset as 1:2, and generates one right eye high data frame and two right eye low data frames from the three right eye data frames of the four right eye data frames except for the black frame data according to the time-division rate that is preset as 1:2. When the received data are in 2-D image mode, the data generator  270  alternately and repeatedly generates the high data frame and the low data frame from the data frames according to a time-division rate that is preset as 1:1. 
     The panel driver  300  displays the frame image on the LCD panel  400 , based on the data provided from the data generator  270  and the control signal provided from the timing controller  250 . The panel driver  300  includes a data driver  310  providing a signal to a data line of the LCD panel, and a gate driver  330  providing the signal to the gate line of the LCD panel  400 . 
     For example, when the received data are in 3-D image mode, the panel driver  300  displays (N−1) left eye frame images, a black frame image, (N−1) right eye frame images and the black frame image, corresponding to the received data frame. When the received data are in 2-D image mode, the panel driver  300  displays the M frame images corresponding to the received data frame. 
       FIG. 3  is a plan view illustrating further details of the LCD panel of  FIG. 1 .  FIG. 4  is an equivalent circuit diagram illustrating the LCD panel in  FIG. 3 . 
     Referring to  FIGS. 3 and 4 , the LCD panel  400  includes: a first substrate, a second substrate facing the first substrate, and a liquid crystal layer disposed between the first and second substrates. The first substrate includes a data line DL, a gate line GL, a voltage line VL, first and second switching elements TR 1  and TR 2 , first and second shield portions SH 1  and SH 2 , and first and second pixel electrodes PE 1  and PE 2 . The second substrate includes a color filter and a light blocking pattern. 
     The LCD panel  400  includes a plurality of pixels. Each of the pixels P includes first and second switching elements TR 1  and TR 2 , first and second shield portions SH 1  and SH 2 , and first and second pixel electrodes PE 1  and PE 2 . The first switching element TR 1  includes a control electrode, an input electrode and an output electrode. The control electrode is connected to the gate line GL, the input electrode is connected to the data line DL, and the output electrode is connected to the first pixel electrode PE 1  through a first contact hole C 1 . The second switching element TR 2  includes the control electrode, the input electrode and the output electrode. The control electrode is connected to the gate line GL, the input electrode is connected to the voltage line VL, and the output electrode is connected to the second pixel electrode PE 2  through a third contact hole C 3 . 
     First and second voltages are alternately applied to the voltage line VL during one frame unit. Here, the first voltage is cathodic with respect to a reference voltage, and the second voltage is anodic with respect to the reference voltage. A voltage between the first and second voltages is applied to the data line DL according to a grayscale level. For example, when the first voltage (being cathodic) is applied to the voltage line VL, a voltage higher than the first voltage (being anodic) is applied to the data line DL according to the grayscale level. Alternatively, when the second voltage (being anodic) is applied to the voltage line VL, a voltage lower than the second voltage (being cathodic) is applied to the data line DL according to the grayscale level. 
     The first shield portion SH 1  is disposed adjacent to the data line DL that applies a data voltage to the pixel P. The first shield portion SH 1  prevents an electric field of the data line DL from leaking out, and blocks light as well. The first shield portion SH 1  includes a first upper shield SU 1  and a first lower shield SD 1  spaced apart from each other. The first upper shield SU 1  is disposed in an upper portion of a pixel area in which the pixel P is defined; and is disposed adjacent to the data line DL. The first lower shield SD 1  is disposed in a lower portion of the pixel are in which the pixel P is defined, and is disposed adjacent to the data line DL. 
     The second shield portion SH 2  is disposed adjacent to the voltage line VL. The second shield portion SH 2  prevents the electric field from leaking out, and blocks light as well. The second shield portion SH 2  includes a second upper shield SU 2 , a second lower shield SD 1  and a connecting shield SC. The second upper shield SU 2  and the second lower shield SD 2  are spaced apart from each other, and the connecting shield SC connects the first lower shield SD 1  with the second upper shield SU 2 . In addition, the second shield portion SH 2  may be disposed adjacent to a neighboring data line that provides data voltages to a neighboring pixel. An end portion of the first upper shield SU 1  may extend generally along the data line to be disposed adjacent to the second upper shield SU 2 , and an end portion of the first lower shield SD 1  may extend generally along the data line to be disposed adjacent to the second lower shield SD 2 . 
     The first upper shield SU 1  is electrically connected to the second pixel electrode PE 2  through a seventh contact hole C 7 , and overlaps with the second pixel electrode PE 2 . The second lower shield SD 2  is electrically connected to the second pixel electrode PE 2  through a fifth contact hole C 5 , and overlaps with the second pixel electrode PE 2 . The first upper shield SU 1  prevents light-leakage between the data line DL and the second pixel electrode PE 2 , and the second lower shield SD 2  prevents light-leakage between the voltage line VL and the second pixel electrode PE 2 . 
     The first lower shield SD 1  is electrically connected to the first pixel electrode PE 1  through a second contact hole C 2 , and partially overlaps with the data line DL. The second upper shield SU 2  is electrically connected to the first pixel electrode PE 1  through a sixth contact hole C 6  and overlaps with the first pixel electrode PE 1 . The first lower shield SD 1  prevents light-leakage between the data line DL and the first pixel electrode PE 1 , and the second upper shield. SU 2  prevents light-leakage between the voltage line VL and the first pixel electrode PE 1 . 
     The first and second shield portions SH 1  and SH 2  may be formed from a metal layer substantially the same as that of the gate line GL. 
     The first pixel electrode PE 1  includes a first column E 11  and a first branch E 12 . The first column E 11  overlaps with the data line DL and the voltage line VL. The first branch E 12  extends to the pixel portion (i.e. the interior pixel area of pixel P) from the first column E 11 , and is inclined at an angle of about 45 degrees (or about 45 degrees). The second pixel electrode PE 2  includes a second column E 21  and a second branch E 22 . The second column E 21  overlaps with the data line DL and the voltage line VL. The second branch E 22  extends to the pixel portion, or interior pixel area of pixel P, from the second column E 21 , and is inclined by an angle of about 45 degrees (or about −45 degrees). The first branch E 12  and the second branch E 22  are alternately disposed. The pixel area in which the pixel P is defined is divided into first and second sub areas A 1  and A 2  according to a gap between the first and second branches E 12  and E 22 . The gap between the first and second branches E 12  and E 22  in the first sub area A 1  has a relatively narrow distance d 1 , and the gap between the first and second branches E 12  and E 22  in the second sub area A 2  has a relatively wide distance d 2 . The first sub area A 1  may be substantially the same as, or smaller than, the second sub area A 2 . 
     The first and second pixel electrodes PE 1  and PE 2  receive voltages different from each other through the data line DL and the voltage line VL. The first and second pixel electrodes PE 1  and PE 2  have horizontal electric fields different from each other in the first and second sub areas A 1  and A 2  according to the gap between first and second branches E 12  and E 22 , and thus liquid crystal molecules may be arranged different from each other in the first and second sub areas A 1  and A 2 . For example, the first and second branches E 12  and E 22 , having the narrow distance d 1  in the first sub area A 1 , form a first liquid crystal capacitor CLCH, and the first and second branches E 12  and E 22 , having the wide distance d 2  in the second sub area A 2 , form a second liquid crystal capacitor CLCL. Thus, the pixel P has a plurality of domains, so that visibility may be enhanced. 
     The first and second pixel electrodes PE 1  and PE 2  may be formed as a transparent conductive layer. 
       FIG. 5A  is a graph showing visibility according to a distance between the first and second pixel electrodes of  FIG. 3 .  FIG. 5B  is a graph showing a V-L curve according to the distance between the first and second electrodes of  FIG. 3 .  FIG. 5C  shows rise time and falling time according to the distance between the first and second electrodes of  FIG. 3 . 
     Referring to  FIGS. 3 and 5A , a simulation result of GDI (Gamma Distortion Index) (right direction) as a function of the magnitude of the wide distance d 2  in the second sub area A 2  is shown when the narrow distance d 1  is 3 μm, 6 μm and 9 μm. The right visibility is a difference between a luminance measured at front (90 degrees) and a luminance measured at side (30 degrees). Thus, difference of the luminances is smaller, the visibility is more enhanced. According to the simulation result, when the narrow distance d 1  is 3 μm, 6 μm and 9 μm and the wide distance d 2  is not less than 9 μm, the GDI (right direction) is not more than about 0.24. Thus, as the wide distance d 2  increases, a GDI (right direction) is further enhanced. 
     The graph showing the V-L curve according to the distance between the first and second electrodes in  FIG. 5B , may explain the reason on the above result. Referring to  FIG. 5B , a difference between a luminance at a high voltage and a luminance at a low voltage is more noticeable when the distance between the first and second pixel electrodes is wide than when the distance between the first and second pixel electrodes is narrow. For example, when the distance between the first and second pixel electrodes is 3 μm, the difference corresponding to a penetration ratio at a voltage of 6V is about 200 nit, and the difference corresponding to the penetration ratio at a voltage of 18V is about 400 nit. However, when the distance between the first and second pixel electrodes is 21 μm, the difference corresponding to the penetration ratio at a voltage of 6V approaches 0 nit, and the difference corresponding to the penetration ratio at a voltage of 18V is about 540 nit. Accordingly, the difference between the luminance at the high voltage and the luminance at the low voltage is more noticeable as the distance between the first and second pixel electrodes increases. Thus, as the distance between the first and second pixel electrodes increases, visibility is more enhanced. 
     The distance between the first and second electrodes affects a rising time and a falling time of a liquid crystal. Referring to  FIG. 5C , the rising times and falling of various liquid crystals according to the distances between the first and second pixel electrodes are measured. 
     When the distance between the first and second pixel electrodes is not more than 11 μm, the rising time is not more than about 6 ms. For example, a fast response speed of the liquid crystal is desirable for the LCD panel having a frame frequency of 480 Hz. In this case, the rising time is preferably about 4 ms, and a falling time is preferably about 2 ms. Under these conditions then, the wide distance d 2  between the first and second pixel electrodes PE 1  and PE 2  should not exceed about 11 μm. The narrow distance d 1  between the first and second pixel electrodes should not be less than about 5 μm considering manufacturing conditions. 
     Referring to  FIGS. 5A ,  5 B and  5 C, a narrow distance d 1  of not more than about 11 μm and a wide distance of not less than about 5 μm may be effective given the above conditions. 
       FIG. 6  is a conceptual diagram explaining a method of displaying a 3-D image using the LCD apparatus of  FIG. 1 . Hereinafter, the method is explained for an LCD apparatus having a frame frequency of 480 Hz. 
     Referring to  FIGS. 1 ,  2 , and  6 , the mode decider  210  decides the image mode of the received data as the 3-D image mode, using the received synchronizing signal, the mode information signal, etc, or according to a mode signal selected by a user. The frame rate controller  230 , the timing controller  250  and the data generator  270  are driven based on a mode deciding signal of the mode decider  210 . 
     The frame rate controller  230  divides the received data frame into left eye data and right eye data for the 3-D image mode, scales each of the left eye data and the right eye data to the resolution of the LCD panel  400 , and generates the left eye data frame and the right eye data frame. Then, the frame rate controller  230  repeats the left data frame to generate four left eye data frames L 1 , L 2 , L 3  and L 4 , and repeats the right data frame to generate four right eye data frames R 1 , R 2 , R 3  and R 4 . 
     The timing controller  250  generates the black data frame and inserts the black data frame between the left data frame and the right data frame for 3-D image mode. Accordingly, the timing controller  250  sequentially outputs a first left eye data frame L 1 , a second left eye data frame L 2 , a third left eye data frame L 3 , a left eye black data frame B 1 , a first right eye data frame R 1 , a second right eye data frame R 2 , a third right eye data frame R 3  and a right eye black data frame B 2 . 
     The data generator  270  generates the high data frame or the low data frame from each of the eight data frames provided from the timing controller  250  according to a time-division rate preset as 1:2 for the 3-D image mode, and outputs either the high data frame or the low data frame. For example, the data generator  270  generates a first left eye low data frame L 1  (Low) from the left eye data frame L 1  using the second data table  272 , generates a second left high data frame L 2  (High) from the second left eye data frame L 2  using the first data table  271 , generates a third left eye low data frame L 3  (Low) from a third left eye data frame L 3  using the second data table  272 , and outputs the left eye black data frame B 1  as is, without alteration. 
     In addition, the data generator  270  generates a right eye low data frame R 1  (Low) from the first right eye data frame R 1  using the second data table  272 , generates a second right eye high data frame R 2  (High) from the second right eye data frame R 2  using the first data table  271 , generates a third right eye low data frame R 3  (Low) from the third right eye data frame R 3  using the second data table  272 , and outputs the right eye black data frame B 2  as is, without alternation. 
     The panel driver  300  sequentially displays the first left eye low data frame L 1  (Low), the second left eye high data frame L 2  (High), the third left eye low data frame L 3  (Low), the left eye black data frame B 1 , the first right eye low data frame R 1  (Low), the second right eye high data frame R 2  (High), the third right eye low data frame R 3  (Low) and the black data frame B 2  on the LCD panel  400 . 
     According to the present example embodiment, the pixel of the LCD panel  400  is space-divided into a plurality of sub areas, and the high data frame and the low data frame are time-divided to be displayed on the LCD panel  400 , so as to enhance visibility of the 3-D image. 
       FIG. 7  is a conceptual diagram explaining a method of displaying a 2-D image using the LCD apparatus in  FIG. 1 . Hereinafter, the method is explained for the case in which the LCD apparatus has a frame frequency of 480 Hz. 
     Referring to  FIGS. 1 ,  2  and  7 , the mode-decider  210  decides the image mode of the received data as the 2-D image mode, using the received synchronizing signal, the mode information signal, etc., or according to the mode signal selected by the user. The frame rate controller  230 , the timing controller  250  and the data generator  270  are driven based on the mode deciding signal of the mode decider  210 . 
     The frame rate controller  230  generates three interpolated data frames Ka, Kb and Kc between a K-th data frame K and a (K+1)-th data frame (K+1), using the K-th data frame K and the (K+1)-th data frame (K+1). This is accomplished by preferably using any motion estimation ME and interpolation method MC for the 2-D image mode. Each of the K-th data frame K and three interpolated data frames. Ka, Kb and Kc are doubled to generate, in order, eight data frames K, K, Ka, Ka, Kb, Kb, Kc and Kc. 
     The timing controller  250  outputs the eight data frames K, K, Ka, Ka, Kb, Kb, Kc and Kc received from the frame rate controller  230  to the data generator  270  according to the 2-D image mode as they are, without modification. 
     The data generator  270  generates the high data frame or the low data frame from each of the eight data frames K, K, Ka, Ka, Kb, Kb, Kc and Kc, and outputs the high data frame or the low data frame, according to a time-division rate preset as 1:1 for the 2-D image mode. For example, the data generator  270  generates and outputs a K-th high data frame K (High), a K-th low data frame K (Low), a first interpolated high data frame Ka (High), a first interpolated low data frame Ka (Low), a second interpolated high data frame Kb (High), a second interpolated low data frame Kb (Low), a third interpolated high data frame Kc (High) and a third interpolated low data frame Kc (Low). 
     The panel driver  300  sequentially displays the K-th high data frame K (High), the K-th low data frame K (Low), the first interpolated high data frame Ka (High), the first interpolated low data frame Ka (Low), the second interpolated high data frame Kb (High), the second interpolated low data frame Kb (Low), the third interpolated high data frame Kc (High) and the third interpolated low data frame Kc (Low) that are provided from the data generator  270 , on the LCD panel  400 . 
     According to the present example embodiment, the pixel of the LCD panel  400  is space-divided into a plurality of sub areas, and the high data frame and the low data frame are time-divided to be displayed on the LCD panel  400 , thus enhancing visibility of the 2-D image. 
     Measurement of Visibility Using Space-Division Method 
     Table 1 shows data of a GDI (right direction) according to an area ratio between the first and second sub areas A 1  and A 2  in the LCD panel of  FIG. 3 . 
     The first and second pixel electrodes of the LCD panel  400  have a narrow distance d 1  of 5 μm in the first sub area, and a wide distance d 2  of 11 μm in the second sub area A 2  for satisfying a specific response. In this case, a GDI (right direction) according to the area ratio between the first and second sub areas A 1  and A 2  was measured. 
     
       
         
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Distance between 
                 Narrow distance(d1): 5 μm/ 
               
               
                 electrodes 
                 Wide distance(d2): 11 μm 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Area ratio 
                 1:1 
                 1:2 
                 1:3 
                 1:4 
                 1:5 
                 1:6 
               
               
                 (A1:A2) 
               
               
                 GDI (right 
                 0.321 
                 0.307 
                 0.300 
                 0.296 
                 0.295 
                 0.294 
               
               
                 direction) 
               
               
                   
               
             
          
         
       
     
     Referring to Table 1, when the ratio between the first and second areas A 1  and A 2  was 1:1, a GDI (right direction) was 0.321. When a ratio between the first and second sub areas A 1  and A 2  was 1:2, a GDI (right direction) was 0.307. When a ratio between the first and second sub areas A 1  and A 2  was 1:3, a GDI (right direction) was 0.300. When the ratio between the first and second sub areas A 1  and A 2  was 1:4, a GDI (right direction) was 0.296. When the ratio between the first and second sub areas A 1  and A 2  was 1:5, a GDI (right direction) was 0.295. When a ratio between the first and second sub areas A 1  and A 2  was 1:6, a GDI (right direction) was 0.294. Thus, as the second sub area A 2  was made larger than the first sub area A 1 , visibility was increasingly enhanced. 
     Measurement of Visibility Using Time-Division Method 
       FIG. 8A  is a graph showing a visibility of the image of an LCD apparatus according to a comparative example embodiment.  FIG. 8B  is a graph showing a visibility of a 2-D image time-divided by the LCD apparatus of  FIG. 1 .  FIG. 8C  is a graph showing a visibility of a 3-D image time-divided by the LCD apparatus of  FIG. 1 . 
     Referring to  FIGS. 8A ,  8 B and  8 C, the first and second pixel electrodes have a narrow distance d 1  of 5 μm in the first sub area and a wide distance d 2  of 11 μm in the second sub area A 2 . 
     Referring to  FIG. 8A , a right visibility of the LCD apparatus according to the comparative example embodiment is shown when the first and second areas A 1  and A 2  are space-divided by a ratio of 1:6 in a 2-D image, without the time-division. As above, a GDI (right direction) was about 0.294 in the LCD apparatus according to the comparative example embodiment. 
     Referring to  FIG. 83 , a right visibility of the LCD apparatus according to the present example embodiment is shown, when the first and second areas A 1  and A 2  are space-divided by a ratio of 1:6, the high and low data frames are time-divided by a ratio of 1:1 and the 2-D image is displayed. In this case, the GDI (right direction) is about 0.255. 
     Referring to  FIG. 8C , the right visibility of the LCD apparatus according to the present example embodiment is shown when the first and second areas A 1  and A 2  are space-divided by the ratio of 1:6, the high and low data frames are time-divided by the ratio of 1:2 and a 3-D image is displayed. In this case, the GDI (right direction) is about 0.194. 
     Referring to  FIGS. 8A ,  8 B and  8 C, a GDI (right direction) is more enhanced when both of the space-division and time division methods are applied, compared to the GDI (right direction) when the space-division method is only applied. For example, the GDI (right direction) is dramatically enhanced when the 3-D image is driven in a condition that the high and low data frames are time-divided by the ratio of 1:2, compared to the GDI (right direction) when the space-division method is only applied. 
     Table 2 shows a response speed of grayscales when a narrow distance between the first and second pixel electrodes is 4 μm, a wide distance between the first and second pixel electrodes is 12 μm, and a rotational viscosity of a liquid crystal is 82. 
     
       
         
               
             
           
               
                 TABLE 2 
               
               
                   
               
             
             
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
             
          
         
       
     
     Referring to Table 2, a falling time, which refers to a time to drop from a high grayscale to a low grayscale, is more satisfactory when the high grayscale moves to the black grayscale, compared to when the low grayscale moves to the black grayscale. For example, the falling time is 1.52 ms when moving from 31 grayscale START to 0 grayscale END, the falling time is lowest, i.e. about 1.21 ms when moving from 63 grayscale START to 0 grayscale END, the falling time is 1.23 ms when moving from 95 grayscale START to 0 grayscale END, and the falling time is 1.31 ms when moving from 127 grayscale START to 0 grayscale END. In contrast, the falling time is 2.37 ms when moving from the high grayscale which is 255 grayscale START to 0 grayscale END. 
     A rising time which refers to a time to rise up from a low grayscale to a high grayscale, is fastest when the black grayscale moves to the low grayscale, compared to when the black grayscale moves to the high grayscale. For example, the rising time is 3.80 ms when moving from 0 grayscale START to 31 grayscale END, the rising time is 2.81 ms when moving from 0 grayscale START to 63 grayscale END, the rising time is 2.03 ms when moving from 0 grayscale START to 95 grayscale END, and the rising time is 2.19 ms when moving from 0 grayscale START to 127 grayscale END. In contrast, the rising time is 4.58 ms when moving from 0 grayscale START to 255 grayscale END. 
     According to the present example embodiment, the black data frame is inserted between the left eye data frame and the right eye data frame at the 3-D image mode. Referring to Table 2, when the time-division method at the 3-D image mode is used, a response speed is faster when a low data frame is positioned before and after the black data frame. As mentioned referring to  FIG. 6 , a response speed may be more enhanced when the third left eye low data frame L 3  (Low) is displayed before the left black data frame B 1  is displayed, and the first right eye low data frame R 1  (Low) is displayed after the left eye black data frame B 1  is displayed, so that the response speed may be more enhanced. 
     According to the present example embodiments, the 3-D image is displayed as a high frequency frame to prevent crosstalk between the left and right eye images. In addition, the pixel is space-divided into first and second sub areas A 1  and A 2  in which the distances between the first and second pixel electrodes are different from each other, and the high data and the low data are time-divided for display on the pixel. This arrangement results in enhanced visibility. 
     While the present disclosure of invention has been particularly provided with reference to example embodiments thereof, it will be understood by those of ordinary skill in the art in view of the foregoing that various changes in form and details may be made therein without departing from the spirit and scope of the present teachings.