Patent Publication Number: US-8976083-B2

Title: Three-dimensional image display device and method for driving the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from and the benefit of Korean Patent Application No. 10-2012-0031865, filed on Mar. 28, 2012, which is hereby incorporated by reference for all purposes as if fully set forth herein. 
     BACKGROUND 
     1. Field 
     Exemplary embodiments of the present invention relate to a three-dimensional (3D) image display device. 
     2. Discussion of the Background 
     The demands for a 3D image display device are increasing. In general, a 3D is image display device may be classified into a glass type 3D image display device that realizes a 3D image with glasses worn by a user and a glassless type 3D image display device that realizes the 3D image without the use of glasses. 
     The glass type 3D image display device may be classified into a shutter glass type 3D image display device and a polarizing film type 3D image display device. The glassless type 3D image display device may be classified into a parallax barrier type 3D image display device and a lenticular type 3D image display device. 
     The polarizing film type 3D image display device may include a patterned retarder disposed on a display panel. The polarizing film type 3D image display device realizes a 3D image using a polarization characteristic of the patterned retarder and a polarization characteristic of a polarization glasses worn by a user. In a polarizing film 3D device, a crosstalk between left image and right image may be smaller and image quality may be increased compared with other types of the 3D image display device. 
     Generally, a 3D image display device is configured to display not only a 3D image but also a two-dimensional (2D) image. However, since the 3D image display device is designed for the display of a 3D image, deterioration in display quality of the 2D image may occur. Therefore, research and development of a 3D image display device capable of both the display of a 2D image and the 3D image are required. In addition, a design change to further reduce power consumption in the 3D image display device as the 3D image display device, e.g., a television set, is increased in size is desired. 
     The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form any part of the prior art. 
     SUMMARY 
     Exemplary embodiments of the present invention provide a 3D image display device to display a 2D image and 3D image and to reduce power consumption by a 3D display device. 
     Exemplary embodiments of the present invention also provide a method of driving the 3D image display device. 
     Additional features of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. 
     An exemplary embodiment of the present invention discloses a three-dimensional (3D) image display device, including: a plurality of data lines; a plurality of gate lines crossing the data lines; a plurality of sub-pixels arranged between the data lines and the gate lines; a data driver configured to drive the data lines; a first gate driver configured to drive first gate lines of the gate lines; a second gate driver configured to drive second gate lines of the gate lines; and a timing controller configured to control the data driver, the first gate driver, and the second gate driver according to an image signal and a control signal, wherein the second gate driver is not driven during a 3D display mode. 
     An exemplary embodiment of the present invention discloses a method of driving a three-dimensional (3D) image display device that includes a plurality of sub-pixels arranged between a plurality data lines and a plurality of gate lines crossing the data lines, the method including: receiving an image signal, a control signal, and a mode signal; controlling a first gate driver according to the image signal and the control signal if the mode signal indicates a 3D is display mode to drive first gate lines of the plurality of gate lines to be sequentially driven; and controlling a second gate driver if the mode signal indicates the 3D display mode to not drive second gate lines of the plurality of gate lines. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention. 
         FIG. 1  is a block diagram of a 3D image display device according to an exemplary embodiment of the present invention. 
         FIG. 2  is an exploded perspective view of the 3D image display device of  FIG. 1 . 
         FIG. 3  is a diagram illustrating a display panel of  FIG. 2 . 
         FIG. 4  is a diagram illustrating a 2D display mode of the display panel of  FIG. 3 . 
         FIG. 5  is a diagram illustrating a 3D display mode of the display panel of  FIG. 3 . 
         FIG. 6  is a flowchart of a method for switching modes in a 3D image display device according to an exemplary embodiment of the present invention. 
         FIG. 7  is a timing diagram of a 3D image display device in a 2D display mode according to an exemplary embodiment of the present invention. 
         FIG. 8  is a timing diagram of a 3D image display device in a 3D display mode is according to an exemplary embodiment of the present invention. 
         FIG. 9  is a timing diagram illustrating an operation of a 3D image display device in a 3D display mode according to an exemplary embodiment of the present invention. 
         FIG. 10  is a timing diagram illustrating an operation of a 3D image display device in a 3D display mode according to an exemplary embodiment of the present invention. 
         FIG. 11  is a flowchart of an operation of a 3D image display device according to an exemplary embodiment of the present invention. 
         FIG. 12  is a timing diagram illustrating an operation of a 3D image display device. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
     The invention is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention 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 is thorough, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of elements, components, and/or sections may be exaggerated for clarity. Like reference numerals in the drawings denote like elements. 
     It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, layer, and/or sections, these elements, components, layer, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, layer, or section from another element, component, layer, or section. Thus, a first element, component, layer, or section discussed below could be is termed a second element, component, layer, or section without departing from the teachings of the present invention. 
     It will be understood that when an element or layer is referred to as being “on” or “connected to” another element components, layer, and/or sections, it can be directly on or directly connected to the other element components, layer, and/or sections, or intervening elements components, layer, and/or sections may be present. In contrast, when an element components, layer, and/or sections is referred to as being “directly on” or “directly connected to” another element components, layer, and/or sections, there are no intervening elements present. It will be understood that for the purposes of this disclosure, “at least one of X, Y, and Z” can be construed as X only, Y only, Z only, or any combination of two or more items X, Y, and Z (e.g., XYZ, XYY, YZ, ZZ). 
       FIG. 1  is a block diagram of a 3D image display device according to an exemplary embodiment of the present invention. Hereinafter, a 3D image display device will be described as if it is a liquid crystal display, but the 3D image display device is not to be limited to the liquid crystal display. Various display devices, such as a field emission display (FED), a plasma display panel (PDP), an inorganic light emitting diode display, an organic light emitting diode display, an electrophoresis display (EPD), etc., may be used as a 3D image display device. 
     Referring to  FIG. 1 , the 3D image display device  100  includes a display panel  110 , a timing controller  120 , a data driver  130 , a first gate driver  140 , and a second gate driver  150 . The 3D image display device  100  may further includes a backlight unit (not shown) disposed under the display panel  110 . 
     The display panel  110  includes a plurality of gate lines G 1  to Gn extending in a first direction X 1 , a plurality of data lines D 1  to Dm extending in a second direction X 2  to cross is the gate lines G 1  to Gn, and a plurality of sub-pixels PX arranged in a matrix form. 
     Although not shown in  FIG. 1 , each sub-pixel may include a thin film transistor connected to a corresponding gate line of the plurality of gate lines and a corresponding data line of the plurality of data lines, a liquid crystal capacitor connected to the thin film transistor, and a storage capacitor connected to the thin film transistor. 
     The timing controller  120  may be configured to receive a first image signal RGB, control signal CTRL, and a mode signal MODE from an external device (not shown). The timing controller  120  may convert the first image signal RGB to a second image signal DATA according to the operational conditions of the display panel  110  on the basis of the control signal CTRL and may apply the second image signal DATA and a control signal CONT to the data driver  130 . The control signal CONT may include a plurality of signals, such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a main clock signal MCLK, a data enable signal, a horizontal synchronization start signal STH, a clock signal HCLK, and a line latch signal TP. The timing controller  120  may apply a first vertical synchronization signal STV 1  and a first vertical clock signal CPV 1  to the first gate driver  140  and may apply a second vertical synchronization signal STV 2  and a second vertical clock signal CPV 2  to the second gate driver  150 . 
     The 3D image display device  100  may operate in a 2D display mode to display a 2D image and in a 3D display mode to display a 3D image. The timing controller  120  is configured to control the display panel  110  to display a 2D image if the mode signal MODE indicates a 2D display mode is selected and to control the display panel  110  to display a 3D image if the mode signal MODE indicates a 3D display mode is selected. 
     The data driver  130  may be configured to output gray-scale voltages to drive the is data lines D 1  to Dm according to the second image signal DATA and the control signal CONT from the timing controller  120 . 
     The first gate driver  140  may be configured to drive first gate lines G 1 , G 3 , . . . , Gn−1 of the gate lines G 1  to Gn according to the first vertical synchronization start signal STV 1  and the first vertical clock signal CPV 1 . 
     The second gate driver  150  may be configured to drive second gate lines G 2 , G 4 , . . . , Gn of the gate lines G 1  to Gn according to the second vertical synchronization start signal STV 2  and the second vertical clock signal CPV 2 . 
     The first gate driver  140  and the second gate driver  150  may be configured to include a gate driving integrated circuit, but it is not to be limited thereto or thereby. The first gate driver  140  and the second gate driver  150  may be configured to include an amorphous silicon gate circuit using an amorphous silicon thin film transistor (a-Si TFT). The first gate driver  140  and the second gate driver  150  may be disposed to the left side and right side, respectively, of the display panel  110 , with the display panel  110  interposed there between. 
     Switching transistors arranged in the same one row may be turned on if one gate line is applied with a gate-on voltage VON by the first gate driver  140  or the second gate driver  150 , to which the switching transistors are connected, and the data driver  130  applies the gray-scale voltages corresponding to the data signal DATA to the data lines D 1  to Dm. The gray-scale voltages provided to the data lines D 1  to Dm may be applied to corresponding sub-pixels, respectively, through the turned-on switching transistors. 
     If the mode signal MODE indicates a 2D display mode, the timing controller  120  may apply the first vertical synchronization start signal STV 1  and the first vertical clock signal CPV 1  to the first gate driver  140  according to the control signal CTRL and may apply the second is synchronization start signal STV 2  and the second vertical clock signal CPV 2  to the second gate driver  150  according to the control signal CTRL. If the mode signal MODE indicates a 3D display mode, the timing controller  120  may apply the first vertical synchronization start signal STV 1  and the first vertical clock signal CPV 1  to the first gate driver  140  according to the control signal CTRL and does not apply the second synchronization start signal STV 2  and the second vertical clock signal CPV 2  to the second gate driver  150  according to the control signal CTRL. The second gate lines G 2 , G 4 , . . . , Gn are not driven during the 3D display mode. The operation of the 3D image display device  100  in the 2D display mode and the 3D display mode will be described in detail below. 
       FIG. 2  is an exploded perspective view of the 3D image display device of  FIG. 1 . 
     Referring to  FIG. 2 , the 3D image display device  100  includes the display panel  110  and a polarizing assembly  200 . 
     The display panel  110  may have a rectangular shape and may display an image through a display area thereof. The display panel  110  may include a lower polarizing plate  112 , a lower substrate  114 , an upper substrate  118 , and a liquid crystal layer  116  interposed between the lower substrate  114  and the upper substrate  118 . 
     The lower substrate  114  may include a thin film transistor array disposed thereon. The thin film transistor array may include the data lines D 1  to Dm to which red, green, and blue data voltages may be applied, the gate lines G 1  to Gn to which a gate pulse may be applied, a plurality of thin film transistors each of which may be electrically connected to the corresponding gate line of the gate lines G 1  to Gn and the corresponding data line of the data lines D 1  to Dm, pixel electrodes to charge a liquid crystal cells with the data voltages, and storage capacitors to maintain the voltage charge in the liquid crystal cells. 
     Although not shown in  FIG. 2 , a color filter or a black matrix may be disposed on at least one of the lower substrate  114  and the upper substrate  118 . A common electrode, which is used to form an electric field in cooperation with the pixel electrodes, may be disposed on the upper substrate  118  in a vertical electric field driving manner, such as a twisted nematic (TN) mode and a vertical alignment (VA) mode, and may be disposed on the lower substrate  114  in a horizontal electric field driving manner, such as an in-plane switching (IPS) mode and a fringe field switching (FFS) mode. The lower substrate  114  and the upper substrate  118  may include an alignment layer disposed on an inner surface thereof to set a pretilt angle of liquid crystal molecules. 
     The first gate driver  140  and the second gate driver  150  illustrated in  FIG. 1  are disposed at both sides of the lower substrate  114  on which the thin film transistor array may be disposed. 
     The lower polarizing plate  112  may be configured to polarize the light provided from a backlight unit (not shown). The liquid crystal molecules of the liquid crystal layer  116  may be aligned in a reference direction according to voltages applied to the pixel electrode and the common electrode to control a transmittance of the light passing there through. Accordingly, the display panel  110  displays selected images. 
     The sub-pixels PX may be arranged on the display panel  110  to allow a left-eye image L and a right-eye image R to be alternately displayed in a line-by-line manner. The sub-pixels PX will be described in detail below. 
     The polarizing assembly  200  includes a polarizing plate  210 , a glass substrate  220 , and a patterned retarder  230 . 
     The polarizing plate  210  may be disposed on the upper substrate  118  and may be is configured to serve as an analyzer to transmit a linearly-polarized light from the light incident thereto after passing through the liquid crystal layer  116  of the display panel  110 . 
     The glass substrate  220  may be coupled with the polarizing plate  210  to support the polarizing plate  210 . The patterned retarder  230  may include first retarder patterns and second retarder patterns alternately arranged with the first retarder patterns. The first retarder pattern and the second retarder pattern may be arranged in a line-by-line manner. The first retarder pattern and the second retarder pattern may be alternately arranged with each other. Every line in the first retarder pattern and the second retarder pattern may be inclined at an angle of about +45 degrees or about −45 degrees with respect to a transmission axis of the polarizing plate  210 . The first retarder pattern and the second retarder pattern are configured to delay a phase of the light by λ/4 using a birefringence medium. The first retarder pattern may have an optical axis substantially perpendicular to an optical axis of the second retarder patterns. Accordingly, the first retarder pattern may be disposed corresponding to lines, in which the left-eye image may be displayed, to convert the light for the left-eye image to a first polarized state (for example, a circularly polarized state or a linearly polarized state). The second retarder pattern may be disposed corresponding to lines, in which the right-eye image may be displayed, to convert the light for the right-eye image to a second polarized state (a circularly polarized state or a linearly polarized state). For instance, the first retarder pattern may include a polarizing filter that transmits a left circularly polarized light and the second retarder pattern may include a polarizing filter that transmits a right circularly polarized light. 
     Polarizing glasses  300  may include a polarizing film disposed on a left-eye glass thereof so as to transmit the first polarized component and a polarizing film disposed on a right-eye glass thereof so as to transmit the second polarized component. Thus, a viewer wearing the is polarizing glasses  300  may recognize the left-eye image through the left eye and the right-eye image through the right eye, so that the viewer perceives the image displayed on the display panel  110  as a 3D image. 
       FIG. 3  is a diagram illustrating a display panel of  FIG. 2 . 
     Referring to  FIG. 3 , the display panel  110  includes the pixel electrodes PX 11  to PXnm and the thin film transistors T 11  to Tnm, which are arranged in areas defined by the data lines D 1  to Dm and the gate lines G 1  to Gn. Each sub-pixel PX may include one pixel electrode and one thin film transistor. One pixel electrode and one thin film transistor may form one sub-pixel PX. One pixel may include three sub-pixels successively arranged in the first direction X 1  in which the gate lines G 1  to Gn extend. A first pixel P 11  may include pixel electrodes PX 11 , PX 12 , and PX 13  and thin film transistors T 11 , T 12 , and T 13 , and a second pixel P 21  includes pixel electrode PX 21 , PX 22 , and PX 23  and thin film transistors T 21 , T 22 , and T 23 . The pixel electrodes PX 11  to PXnm may sequentially display red, green, and blue colors in the first direction X 1  beginning with the pixel electrode PX 11  adjacent to the first gate driver  140 . For example, the three pixel electrodes PX 11 , PX 12 , and PX 13  may display the red color, the green color, and the blue color, respectively. Although not shown in the figures, each sub-pixel may include a storage capacitor. 
     The first gate driver  140  may be disposed at a left side of the display panel  110  and the second gate driver  150  may be disposed at a right side of the display panel  110 . The first gate driver  140  may include k amorphous silicon gate (ASG) circuits LASG 1  to LASGk (where k is a natural number and k=n/2) and the second gate driver  150  may include k ASG circuits RASG 1  to RASGk. The ASG circuits LASG 1  to LASGk drive the first gate lines G 1 , G 3 , . . . , Gn−1, respectively, and the ASG circuits RASG 1  to RASGk drive the second gate lines G 2 , G 4 , . . . , Gn, respectively. 
     If first gate driver  140  and second gate driver  150  are separated from each other and disposed on both sides of the display panel  110 , a circuit width of the first gate driver  140  and second gate driver  150  may be reduced in the first direction X 1 . Thus, a narrow bezel of the display panel  110  may be easily realized. 
     Gate terminals of odd-numbered thin film transistors in the second direction X 2  are connected to the first gate lines G 1 , G 3 , . . . , Gn−1, e.g., odd-numbered gate lines, extended from the first gate driver  140 . Gate terminals of even-numbered thin film transistors in the second direction X 2  are connected to the second gate lines G 2 , G 4 , . . . , Gn, e.g., even-numbered gate lines, extended from the second gate driver  150 . First pixels P 11 , P 31 , . . . P(n−1)1 may be connected to the first gate lines G 1 , G 3 , . . . , Gn−1, respectively, and second pixels P 21 , P 41 , . . . , Pn 1  may be connected to the second gate lines G 2 , G 4 , . . . , Gn, respectively. 
     During operation in a 2D display mode, the first gate driver  140  may drive the first gate lines G 1 , G 3 , . . . , Gn−1 and the second gate driver  150  may drive the second gate lines G 2 , G 4 , . . . , Gn. In contrast, during a 3D display mode, the first gate driver  140  may drive the first gate lines G 1 , G 3 , . . . , Gn−1 but the second gate driver  150  does not drive the second gate lines G 2 , G 4 , . . . , Gn. Thus, the second pixels P 21 , P 41 , . . . , Pn 1  may be connected to the second gate lines G 2 , G 4 , . . . , Gn, respectively, to display a black image. Since the second pixels P 21  to Pn 1  display the black image while the first pixels P 11  to P(n−1)1 display the 3D image, the second pixels P 21 , P 41 , . . . , Pn 1  may serve as black stripes. The black stripes may widen a vertical viewing angle of the 3D display device if a 3D image is displayed and a crosstalk between the first pixels P 11  to P(n−1)1 may be reduced. 
       FIG. 4  is a diagram illustrating a 2D display mode of the display panel of  FIG. 3 .  FIG. 5  is a diagram illustrating a 3D display mode of the display panel of  FIG. 3 .  FIG. 4  and  FIG. 5  will be described with reference to the sub-pixels of  FIG. 3 , but are not limited thereto. 
     Referring to  FIG. 4  and  FIG. 5 , a length in the second direction X 2  of each of the first pixels P 11 , P 31 , P 51 , and P 71 , that is, a vertical pitch PC 1  of each of the first pixels P 11 , P 31 , P 51 , and P 71 , is longer than a vertical pitch PC 2  of each of the second pixels P 21 , P 41 , P 61 , and P 81 . The vertical pitch PC 2  of the second sub-pixels may a vertical viewing angle and the brightness of the 3D image if a 3D image is displayed. Therefore, the vertical pitch PC 1  of the first sub-pixels P 11 , P 31 , P 51 , and P 71  and the vertical pitch PC 2  of the second sub-pixels P 21 , P 41 , P 61 , and P 81  may be selected according to the vertical viewing angle and the brightness of the 3D image. 
     In the 2D display mode, the first image signal RGB may be displayed in the first pixels P 11 , P 31 , P 51 , and P 71  connected to the first gate lines G 1 , G 3 , . . . , Gn−1 and the second pixels P 21 , P 41 , P 61 , and P 81  connected to the second gate lines G 2 , G 4 , . . . , Gn as shown in  FIG. 3  and  FIG. 4 . 
     In the 3D display mode, the first image signal RGB may be displayed in the first pixels P 11 , P 31 , P 51 , and P 71  connected to the first gate lines G 1 , G 3 , . . . , Gn−1, and the second pixels P 21 , P 41 , P 61 , and P 81  connected to the second gate lines G 2 , G 4 , . . . , Gn may display the black image as shown in  FIG. 3  and  FIG. 5 . Thus, the second pixels P 21 , P 41 , P 61 , and P 81  may serve as the black stripes during the 3D display mode. 
     Two first pixels P 11  and P 51  of the first pixels P 11 , P 31 , P 51 , and P 71  may display the left-eye image and two first pixels P 31  and P 71  of the first pixels P 11 , P 31 , P 51 , and P 71  may display the right-eye image. The 3D image display device  100  may alternately displays the left-eye image and the right-eye image on the display panel  110 , and the 3D image may be is realized by the polarization characteristic of the patterned retarder and the polarization characteristic of the polarizing glasses  300  worn by the user. The left-eye image and the right-eye image may be spatially separated from each other to realize the 3D image. A visibility of a 3D image may be deteriorated by the crosstalk generated in the vertical viewing angle. For example, if the viewer watches the display panel  110  at an upper position or a lower position of the display panel  110 , a crosstalk, in which the left-eye image and the right-eye image overlap with each other while passing through the patterned retarder  230 , may be generated in the vertical viewing angle larger than a reference angle in comparison with a front viewing angle. The second pixels P 21 , P 41 , P 61 , and P 81  may serve as active black stripes during the 3D display mode. The first pixels P 11  and P 51  may display the left-eye image and may be separated from the first pixels P 31  and P 71  in which the right-eye image may be displayed. The 3D image display device  100  may reduce crosstalk. 
       FIG. 6  is a flowchart of a method for switching modes in a 3D image display device according to an exemplary embodiment of the present invention.  FIG. 7  is a timing diagram of a 3D image display device in a 2D display mode according to an exemplary embodiment of the present invention.  FIG. 8  is a timing diagram of a 3D image display device in a 3D display mode according to an exemplary embodiment of the present invention.  FIG. 6 ,  FIG. 7 ,  FIG. 8  will be described with reference to the 3D image display device  100  of  FIG. 1 , but are not limited thereto. 
     Referring to  FIG. 1 ,  FIG. 6 ,  FIG. 7  and  FIG. 8 , in operation S 110 , the 3D image display device  100  determines a display mode for an image. The timing controller  120  may check the mode signal MODE from the external device (not shown) to determine the selected display mode. In operation S 120 , if the display mode is determined to be a 2D display mode (i.e., the mode signal MODE indicates a 2D display mode), the 3D image display device drives the first gate lines and the second gate lines. The timing controller  120  may apply the first vertical synchronization start signal STV 1  and the first vertical clock signal CPV 1  to the first gate driver  140  and may apply the second vertical synchronization start signal STV 2  and the second vertical clock signal CPV 2  to the second gate driver  150 . Accordingly, the first gate lines G 1 , G 3 , . . . , Gn−1 and the second gate lines G 2 , G 4 , . . . , Gn may be sequentially driven to display a 2D image. 
     In operation S 130 , the 3D image display device  100  If the display mode is determined to be a 2D display mode (i.e., the mode signal MODE indicates the 3D display mode), the 3D image display device drives the first gate lines. The timing controller  120  may apply the first vertical synchronization start signal STV 1  and the first vertical clock signal CPV 1  to the first gate driver  140  but does not apply the second vertical synchronization start signal STV 2  and the second vertical clock signal CPV 2  to the second gate driver  150 . Accordingly, the first gate lines G 1 , G 3 , . . . , Gn may be sequentially driven to display the 3D image. Since the second gate lines G 2 , G 4 , . . . , Gn are not driven during the 3D display mode, the second pixels P 11  to Pn 1  connected to the second gate lines G 2 , G 4 , . . . , Gn display a black image. 
     Referring to  FIG. 7 , the signal used to drive the data line Di (1≦i≦m) in the 2D display mode may have a frequency of about 240 Hz. If the same signal is used to drive the data line Di in a 3D display mode shown, as illustrated in  FIG. 8 , the frequency of the data line Di may be about 120 Hz. The timing controller  120  may control the frequency of the second image signal DATA to be from about 240 Hz to about 120 Hz when the mode signal MODE indicates the 3D display mode. 
     Since the second gate driver  150  is not driven during the 3D display mode, the is power consumption in the 3D image display device  100  may be reduced compared to the power consumed in the 2D display mode. The signal used to drive the data line Di (1≦i≦m) in the 3D display mode may have a relatively low frequency, and thus the power consumption in the 3D image display device  100  may be reduced. 
       FIG. 9  is a timing diagram illustrating an operation of a 3D image display device in a 3D display mode according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 9 , the signal used to drive the data line Di (1≦i≦m) in the 3D display mode may have a frequency of about 240 Hz. The data line Di may be driven by the gray-scale voltage corresponding to the second image signal DATA and then driven by the common voltage VCOM if the first gate lines G 1 , G 3 , . . . , Gn−1 are driven. 
       FIG. 10  is a timing diagram illustrating an operation of a 3D image display device in a 3D display mode according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 10 , a time interval during which the gate lines G 1 , G 3 , . . . , Gn−1 are driven according to the gate-on voltage in the 3D display mode may be substantially the same as a time interval during which two adjacent first gate lines are driven in the 2D display mode. 
       FIG. 11  is a flowchart of an operation of a 3D image display device according to an exemplary embodiment of the present invention.  FIG. 12  is a timing diagram illustrating an operation of a 3D image display device. Although  FIG. 11  and  FIG. 12  are described as if performed by the 3D image display device of  FIG. 1 , they are not limited thereto. 
     Referring to  FIG. 11  and  FIG. 12 , in operation S 210 , the 3D image display device  100  operating in a 2D display mode determines if a switch to a 3D display mode is detected. The 3D image display device  100  determines if the mode signal MODE indicates the 2D display mode is to be changed to the 3D display mode. In operation S 220 , the 3D image display device  100  displays a black image if a signal to change from the 2D display mode to the 3D display mode is received. The timing controller  120  display the black image on the display panel  110  during a reference frame which may be a refresh mode. The refresh mode may be maintained for at least one frame. 
     During the refresh mode, the timing controller  120  may control the display panel  110  to allow the first pixel P 11  to P(n−1)1 and second pixel P 21  to Pnm to display a black image or to control the second pixels P 21  to Pnm connected to the second gate lines G 2 , G 4 , . . . , Gn to display the black image. The timing controller  120  may control the first pixels P 11  to P(n−1)1 connected to the first gate lines G 1 , G 3 , . . . , Gn−1 to display the 2D image of the previous frame while the second pixels P 21  to Pnm connected to the second gate lines G 2 , G 4 , . . . , Gn display the black image. 
     In operation S 230 , the 3D image display device  100  operates in a 3D display mode. After the black image is displayed on the display panel for the reference frame, the timing controller  120  controls the 3D image display device  100  to operate in the 3D display mode. 
     Although the second gate lines G 2 , G 4 , . . . , Gn are not driven during the 3D display mode, the second pixels connected to the second gate lines G 2 , G 4 , . . . , Gn may continuously display a black image since the second pixels connected to the second gate lines G 2 , G 4 , . . . , Gn display the black image during the refresh mode. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.