KR101991897B1 - Display device and driving method thereof - Google Patents

Abstract

The present invention relates to a display device and a driving method thereof, and a driving method of a display device according to an embodiment of the present invention includes a plurality of pixels A method of driving a display device including pixels, the method comprising: storing gamma data for two or more gamma curves in a memory; generating a gradation voltage based on the gamma data; Wherein each of the first and second pixels receives the data voltage and generates one input video signal during a first set of frames including two or more consecutive frames, Wherein each of the first pixel and the second pixel includes a first frame and a second frame, Wherein a gamma curve of an image displayed by the first pixel is different from a gamma curve of an image displayed by the second pixel during one frame, The images displayed by two pixels adjacent to each other and representing the same color among a plurality of pixels follow different gamma curves.

Description

DISPLAY DEVICE AND DRIVING METHOD THEREOF [0002]

The present invention relates to a display apparatus and a driving method thereof, and more particularly to a display apparatus and a driving method thereof that can improve visibility.

A display device such as a liquid crystal display (LCD) or an organic light emitting diode (OLED) display generally includes a display panel having a plurality of pixels including a switching element and a plurality of signal lines, And a data driver for generating a plurality of gradation voltages using the gradation reference voltage and applying a gradation voltage corresponding to the input image signal among the generated gradation voltages as data signals to the data lines.

The liquid crystal display device includes a liquid crystal layer having a dielectric anisotropy and two display panels provided with a pixel electrode and a counter electrode. The pixel electrodes are arranged in the form of a matrix and connected to a switching element such as a thin film transistor (TFT), and are supplied with a data voltage one row at a time. The counter electrode is formed over the entire surface of the display panel and receives the common voltage Vcom. A desired image can be obtained by applying a voltage to the pixel electrode and the counter electrode to generate an electric field in the liquid crystal layer and adjusting the intensity of the electric field to adjust the transmittance of light passing through the liquid crystal layer.

In order to solve this problem, a method of dividing one pixel into two sub-pixels and varying the voltages of two sub-pixels has been proposed. If one pixel is divided into two sub-pixels as described above, the opening through which light can pass through is reduced, and the transmittance may be lowered.

A problem to be solved by the present invention is to provide a display device and a method of driving the same that can improve transmittance and side viewability and display quality.

A method of driving a display device according to an exemplary embodiment of the present invention includes a plurality of pixels that display an image in units of frames and include neighboring first and second pixels, Generating gamma data based on the gamma data, inputting an input video signal from the outside, and converting the input video signal into a data voltage using the gradation voltage, Wherein each of the first pixel and the second pixel includes a step of displaying an image corresponding to one input image signal during a first set of frames including two or more consecutive frames by receiving the data voltage, Wherein the image displayed by the first pixel and the second pixel during the first frame set is a gamma curve corresponding to a different gamma curve, Wherein a gamma curve followed by an image displayed by the first pixel and a gamma curve followed by an image displayed by the second pixel during one frame are different from each other and two adjacent pixels of the plurality of pixels, The images displayed by the pixels follow different gamma curves.

Wherein the image displayed by the first pixel during the first set of frames includes a first image along the first gamma curve and a second image along the second gamma curve, The luminance of the image is not lower than that of the image, and the second image with respect to the first pixel can be displayed in two consecutive frames.

The first image and the second image displayed by the first pixel in the first frame set and the first image and the first image displayed by the first pixel in a second frame set continuing to the first frame set, The order of the second images may be opposite to each other.

The polarities of the data voltages applied to two neighboring data lines among the plurality of data lines may be opposite to each other.

Pixels arranged in a pixel column direction among the plurality of pixels may be alternately connected to two different data lines among the plurality of data lines.

The polarity of the data voltage applied to the plurality of pixels may be reversed every frame.

The polarity of the data voltage applied to the plurality of pixels may be inverted every two or more frames.

Pixels arranged in the pixel column direction among the plurality of pixels may be connected to the same data line among the plurality of data lines.

The polarity of the data voltage applied to the plurality of pixels may be reversed every frame.

The polarity of the data voltage applied to the plurality of pixels may be inverted every two or more frames.

Wherein the image displayed by the first pixel during the first set of frames includes a first image along the first gamma curve and a second image along the second gamma curve, The first image and the second image with respect to the first pixel may be alternately displayed for each frame.

Pixels arranged in a pixel column direction among the plurality of pixels may be alternately connected to two different data lines among the plurality of data lines.

Wherein the polarity arrangement order of the data voltages applied to the first pixel in the first frame set is opposite to the polarity arrangement order of the data voltages applied to the first pixel in a second frame set subsequent to the first frame set Lt; / RTI >

Each of the first pixel and the second pixel may include a first sub-pixel and a second sub-pixel.

A display device according to an embodiment of the present invention includes a memory for storing gamma data for two or more gamma curves, a gradation voltage generator for generating a gradation voltage based on the gamma data, a signal for receiving an input video signal from the outside A data driver for receiving the input video signal from the signal controller and converting the input video signal to a data voltage using the gradation voltage, a plurality of data lines for transmitting the data voltage, And a display panel including a plurality of pixels each displaying an image in units of frames, wherein the plurality of pixels include a first pixel and a second pixel neighboring each other and displaying an image corresponding to each input image signal , Each of the first pixel and the second pixel includes two or more consecutive frames Wherein the image displayed by the first pixel and the second pixel during the first set of frames includes an image according to a different gamma curve, , A gamma curve along an image displayed by the first pixel and a gamma curve along an image displayed by the second pixel during one frame are different from each other and two pixels neighboring to each other and representing the same color are displayed The images follow different gamma curves.

According to the embodiment of the present invention, it is possible to improve the transmittance and lateral visibility of the display device and to improve the display quality of the display device.

1 is a block diagram of a display device according to an embodiment of the present invention,
2 is a simplified circuit diagram of one pixel of a display device according to an embodiment of the present invention,
FIG. 3 is a view showing two sub-pixels included in one pixel of a display device according to an embodiment of the present invention,
4 is an equivalent circuit diagram of one pixel of a display device according to an embodiment of the present invention,
5 is a plan view of one pixel of a display device according to an embodiment of the present invention,
6 is a cross-sectional view taken along the line VI-VI of the display device of FIG. 5,
7 is an equivalent circuit diagram of one pixel of a display device according to an embodiment of the present invention,
8A and 8B are plan views of one pixel of a display device according to an embodiment of the present invention,
9 is a cross-sectional view cut along the line IX-IX of the display device of Fig. 8A,
10, 11 and 12 are equivalent circuit diagrams of one pixel of a display device according to an embodiment of the present invention,
13 and 14 are simplified circuit diagrams of a plurality of pixels of a display device according to an embodiment of the present invention,
15 and 16 are graphs respectively showing gamma curves of a display device according to an embodiment of the present invention,
17 is a diagram showing the polarities of the luminance and data voltages of a plurality of pixels of the display device according to an embodiment of the present invention in frame order,
FIGS. 18A, 18B, 18C, 18D, 18E and 18F are diagrams illustrating the brightness of one pixel of a display device according to an embodiment of the present invention in frame order,
FIGS. 19 to 33 are diagrams showing, in frame order, the brightness and the polarity of the data voltages of the plurality of pixels of the display device according to the embodiment of the present invention, respectively.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Now, a display device and a driving method thereof according to an embodiment of the present invention will be described in detail with reference to the drawings.

First, a display device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 12. FIG.

FIG. 2 is a simplified circuit diagram of one pixel of a display device according to an embodiment of the present invention, and FIG. 3 is a schematic circuit diagram of a display device according to an embodiment of the present invention. Fig. 8 is a diagram showing two sub-pixels included in one pixel of the display device. Fig.

1, a display device according to an exemplary embodiment of the present invention includes a display panel 300, a gate driver 400 and a data driver 500 connected to a display panel 300, a data driver 500, An associated gray scale voltage generator 800, a signal controller 600 for controlling the gray scale voltage generator 800, and a memory 650 connected to the signal controller 600.

The display panel 300 includes a plurality of signal lines connected to an equivalent circuit and a plurality of pixels PX arranged in the form of a matrix. When the display device according to an embodiment of the present invention is a liquid crystal display device, the display panel 300 may include a lower and an upper panel (not shown) facing each other and a liquid crystal layer ).

The signal line includes a plurality of gate lines G1-Gn for transferring gate signals (also referred to as "scan signals") and a plurality of data lines D1-Dm for transferring data voltages.

2, a pixel PX included in a display device according to an exemplary embodiment of the present invention includes at least one switching element connected to at least one data line Dj and at least one gate line Gi Q and at least one pixel electrode 191 connected thereto. The switching element Q may include at least one thin film transistor and is controlled in accordance with a gate signal Vg transmitted by the gate line Gi so that the data voltage Vd, (191).

Referring to FIG. 3, one pixel PX of the display device according to another embodiment of the present invention may include a first sub-pixel PXa and a second sub-pixel PXb. The first subpixel PXa and the second subpixel PXb may display an image according to a different gamma curve for one input image signal IDAT or an image according to the same gamma curve. The areas of the first sub-pixel PXa and the second sub-pixel PXb may be the same or different.

Various structures of the pixel PX including the first sub-pixel PXa and the second sub-pixel PXb will be described with reference to FIGS. 4 to 12. FIG.

First, a display device according to an embodiment of the present invention will be described with reference to FIGS. 4, 5, and 6. FIG.

5 is a plan view of a pixel of a display device according to an embodiment of the present invention, FIG. 6 is a cross-sectional view of the display device of FIG. 5, Sectional view taken along line VI-VI.

4, a display device according to an exemplary embodiment of the present invention includes a signal line including a gate line 121, a depression gate line 123, and a data line 171 and a pixel connected thereto PX).

Each pixel PX includes first and second sub-pixels PXa and PXb. The first subpixel PXa includes a first switching device Qa, a first liquid crystal capacitor Clca and a first holding capacitor Csta. The second subpixel PXb includes a first switching device Qa, a first liquid crystal capacitor Clca, The second storage capacitors Csta and Cstb, and the reduced-pressure storage capacitor Cstd, in addition to the elements Qa, Qb, and Qc, the second liquid crystal capacitors Clca and Clcb,

The first and second switching elements Qa and Qb are connected to the gate line 121 and the data line 171 respectively and the third switching element Qc is connected to the voltage-

The first and second switching elements Qa and Qb are three terminal elements such as a thin film transistor and the control terminal thereof is connected to the gate line 121. The input terminal is connected to the data line 171, Terminals are connected to the first and second liquid crystal capacitors Clca and Clcb and the first and second storage capacitors Csta and Cstb, respectively.

The third switching element Qc is also a three terminal element such as a thin film transistor. The control terminal is connected to the depressurizing gate line 123, the input terminal is connected to the second liquid crystal capacitor Clcb, And is connected to the capacitor Cstd.

The decompression capacitor Cstd is connected to an output terminal of the third switching device Qc and a common voltage.

When the gate-on voltage Von is applied to the gate line 121, the first and second thin film transistors Qa and Qb connected thereto are turned on. The data voltage of the data line 171 is applied to the first and second liquid crystal capacitors Clca and Clcb through the turned on first and second switching devices Qa and Qb to be supplied to the first and second liquid crystal capacitors Clca and Clcb are charged with the difference between the data voltage Vd and the common voltage Vcom. At this time, the gate-off voltage Voff is applied to the decompression gate line 123.

Next, when the gate-off voltage Voff is applied to the gate line 121 and the gate-on voltage Von is applied to the decompression gate line 123, the first and second switching elements Qa , Qb are turned off, and the third switching element Qc is turned on. As a result, the charging voltage of the second liquid crystal capacitor Clcb connected to the output terminal of the second switching device Qb drops.

A case where the liquid crystal display according to the present embodiment is driven by a frame inversion and a data voltage Vd having a positive polarity is applied to the data line 171 in the current frame based on the common voltage Vcom is exemplified In other words, negative charge is accumulated in the decompression capacitor Cstd after the previous frame ends. When the third switching element Qc is turned on in the current frame, the positive charge of the second liquid crystal capacitor Clcb flows into the reduced-pressure accumulator Cstd via the third switching element Qc, The positive charge is collected and the charge voltage of the second liquid crystal capacitor Clcb is decreased. In the next frame, conversely, when the third switching element Qc is turned on in a state in which the negative charge is charged in the second liquid crystal capacitor Clcb, the negative charge of the second liquid crystal capacitor Clcb is The negative charge flows into the decompression capacitor Cstd and the voltage of the second liquid crystal capacitor Clcb falls.

As described above, according to the present embodiment, the charging voltage of the second liquid crystal capacitor Clcb can be made lower than the charging voltage of the first liquid crystal capacitor Clca irrespective of the polarity of the data voltage Vd. Therefore, the charging voltage of the first and second liquid crystal capacitors Clca and Clcb can be made different from each other, thereby improving lateral visibility of the liquid crystal display device.

A specific structure of the liquid crystal display device shown in FIG. 4 will now be described with reference to FIGS. 5 and 6. FIG.

5 and 6, the liquid crystal display according to the present embodiment includes a lower panel 100 and an upper panel 200 facing each other, a liquid crystal layer 3 interposed between the two panels 100 and 200, . A polarizer (not shown) may be provided on the outer surface of the display panels 100 and 200.

First, the upper panel 200 will be described. An opposing electrode 270 is formed on the insulating substrate 210. The counter electrode 270 may be made of a transparent conductor such as ITO or IZO or a metal. An alignment film (not shown) may be formed on the counter electrode 270.

The liquid crystal layer 3 interposed between the lower panel 100 and the upper panel 200 includes liquid crystal molecules having dielectric anisotropy and the liquid crystal molecules are arranged such that their long axes are parallel to the surface of the two panels 100 and 200 As shown in Fig. The liquid crystal molecules of the liquid crystal layer 3 may be pretilted such that the long axis thereof is substantially parallel to the longitudinal direction of the fine branch portions 199a and 199b of the first and second sub-pixel electrodes 191a and 191b. To this end, the liquid crystal layer 3 may further comprise an alignment aid comprising a reactive mesogen.

Next, the lower display panel 100 will be described.

A plurality of gate conductors including a plurality of gate lines 121, a plurality of depressed gate lines 123 and a plurality of sustain electrode lines 125 are formed on an insulating substrate 110. [

The gate line 121 and the decompression gate line 123 extend mainly in the lateral direction and transfer gate signals. The gate line 121 may include a first gate electrode 124a and a second gate electrode 124b protruding upward and downward and the decompression gate line 123 may include a third gate electrode 124c protruding upwardly. have. The first gate electrode 124a and the second gate electrode 124b may be connected to each other to form one protrusion.

The sustain electrode line 125 can also extend mainly in the lateral direction and can be positioned directly above the gate line 121 and transmit a predetermined voltage such as the common voltage Vcom. The sustain electrode line 125 includes a sustain extension portion 126, a pair of vertical portions 128 that extend substantially vertically to the gate line 121, and a pair of vertical portions 128 But the structure of the sustain electrode line 125 is not limited thereto.

A gate insulating layer 140 is formed on the gate conductors 121, 123, and 125.

On the gate insulating film 140, a plurality of linear semiconductors 151, which can be made of amorphous or crystalline silicon, are formed. The linear semiconductor 151 mainly includes first and second semiconductors 154a and 154b that extend in the longitudinal direction and extend toward the first and second gate electrodes 124a and 124b and are connected to each other, And a third semiconductor 154c connected to the second semiconductor layer 154b.

A plurality of linear resistive ohmic contacts 161 are formed on the linear semiconductor 151. Resistive contact members 163a and 165a are formed on the first semiconductor 154a, And the third semiconductor 154c may also be formed with resistive contact members, respectively. The resistive contact member 165a may protrude from the linear resistive contact member 161. However, depending on the type of the semiconductor 151, the resistive contact members 161 and 165a may be omitted.

A plurality of data lines 171, a plurality of first drain electrodes 175a, a plurality of second drain electrodes 175b and a plurality of third drain electrodes 175c are formed on the resistive contact members 161 and 165a A data conductor is formed.

The data line 171 carries a data signal and extends mainly in the vertical direction and intersects the gate line 121 and the decompression gate line 123. Each data line 171 may include a first source electrode 173a and a second source electrode 173b extending toward the first gate electrode 124a and the second gate electrode 124b.

The first drain electrode 175a, the second drain electrode 175b, and the third drain electrode 175c may include a wide one end and a rod-shaped other end. The rod-shaped end portions of the first drain electrode 175a and the second drain electrode 175b are partially surrounded by the first source electrode 173a and the second source electrode 173b. The wide one end of the second drain electrode 175b may extend again to form a third source electrode 173c bent in a U-shape. The wide end portion 177c of the third drain electrode 175c overlaps with the sustaining extension portion 126 to form a reduced-pressure storage capacitor Cstd and the rod-end portion is partially surrounded by the third source electrode 173c.

Second and third source electrodes 173a / 173b / 173c and first / second / third drain electrodes 175a / 175b (corresponding to the first / second / third gate electrodes 124a / 124b / 124c, 175c together with the first / second / third semiconductors 154a / 154b / 154c form one first / second / third thin film transistor (TFT) Qa / Qb / Qc Channel of the thin film transistor is formed in each semiconductor 154a / 154b / 154c between each source electrode 173a / 173b / 173c and each drain electrode 175a / 175b / 175c.

A lower protective film 180p that can be made of an inorganic insulating material such as silicon nitride or silicon oxide is formed on portions of the data conductors 171, 175a, 175b, and 175c and exposed semiconductors 154a, 154b, and 154c.

The color filter 230 and the light shielding member 220 may be disposed on the lower protective film 180. The light shielding member 220 includes a portion covering the region where the first thin film transistor Qa, the second thin film transistor Qb and the third thin film transistor Qc are located and a portion extending along the data line 171 . The light shielding member 220 includes an opening 227 located on the first thin film transistor Qa and the second thin film transistor Qb, an opening 226a located on the wide end of the first drain electrode 175a, An opening 226b located above the wide end of the drain electrode 175b and an opening 228 located above the third thin film transistor Qc. Alternatively, at least one of the color filter 230 and the light shielding member 220 may be located on the upper panel 200.

The upper protective film 180q may be formed on the color filter 230 and the light shielding member 220. [

A plurality of contact holes 185a and 185b are formed in the lower protective film 180p and the upper protective film 180q to expose the first drain electrode 175a and the second drain electrode 175b, respectively. The contact holes 185a and 185b may be located in the openings 226a and 226b of the light shielding member 220. [

A pixel electrode including a first sub-pixel electrode 191a and a second sub-pixel electrode 191b is formed on the upper protective layer 180q.

The first and second sub-pixel electrodes 191a and 191b may be adjacent to each other in the column direction and the height of the second sub-pixel electrode 191b may be higher than the height of the first sub-pixel electrode 191a.

The overall shape of the first sub-pixel electrode 191a is a rectangle. The first sub-pixel electrode 191a has a rectangular shape, and includes an outer frame portion defining an outer frame, a ten-trunk portion 195a including a horizontal trunk portion and a vertical trunk portion therein, And a plurality of fine branch portions 199a extending obliquely outwardly from the projecting portions 195a. A fine slit 91a is located between neighboring fine branch portions 199a.

The overall shape of the second sub-pixel electrode 191b is also a quadrangle. The second sub-pixel electrode 191b has a rectangular shape, and includes an outer frame portion defining an outer frame, a ten-trunk portion 195b including a horizontal trunk portion and a vertical trunk portion therein, And a plurality of fine branch portions 199b extending obliquely outwardly from the projecting portions 195b. A fine slit 91b is located between neighboring fine branch portions 199b.

Each of the first sub-pixel electrode 191a and the second sub-pixel electrode 191b is divided into four sub-regions by the respective criss-crossing bases 195a and 195b. Referring to FIG. 5, each sub-region of the second sub-pixel electrode 191b may include a region where the interval between the fine branches 199b is different depending on the position. Alternatively, the interval between the fine branches 199b Can be constant. The specific structure of the first and second sub-pixel electrodes 191a and 191b is not limited to the example shown in FIG. 5, and may be variously modified. The sizes of the respective portions are also determined by the cell gap, And so on.

The first sub-pixel electrode 191a receives a data voltage from the first drain electrode 175a through the contact hole 185a and the second sub-pixel electrode 191b receives a data voltage from the second drain electrode 175a through the contact hole 185b. The data voltage can be supplied from the data line 175b.

An alignment layer (not shown) may be formed on the first and second sub-pixel electrodes 191a and 191b and the upper passivation layer 180q.

The first and second sub-pixel electrodes 191a and 191b generate an electric field together with the opposing electrode 270 of the upper panel 200 so that the direction of the liquid crystal molecules in the liquid crystal layer 3 between the two electrodes 191 and 270 . The degree of change of the polarization of the light incident on the liquid crystal layer 3 varies depending on the degree of tilting of the liquid crystal molecules. The change of the polarization is caused by the change of the transmittance by the polarizer, and the liquid crystal display displays the image.

On the other hand, the sides of the fine branches 199a and 199b or the fine slits 91a and 91b included in the first and second sub-pixel electrodes 191a and 191b may distort the electric field and cause the fine branches 199a and 199b or fine A horizontal component perpendicular to the sides of the slits 91a and 91b is produced, and the oblique direction of the liquid crystal molecules is determined in a direction determined by the horizontal component. The liquid crystal molecules are initially tilted in the direction perpendicular to the sides of the fine branch portions 199a and 199b or the fine slits 91a and 91b but the neighboring fine branch portions 199a and 199b or the fine slits 91a and 91b, The liquid crystal molecules to be tilted in opposite directions to each other due to the direction of the horizontal component of the electric field due to the sides of the fine branches 199a and 199b or the fine slits 91a and 91b are narrow, , 199b) or in the direction parallel to the length direction of the fine slits (91a, 91b).

Since the first and second sub-pixel electrodes 191a and 191b include four sub-regions having different lengths of the micro branches 199a and 199a in the embodiment of the present invention, the liquid crystal molecules of the liquid crystal layer 3 The inclination direction becomes all four directions and the reference viewing angle of the liquid crystal display device can be increased.

The first sub pixel electrode 191a and the counter electrode 270 form a first liquid crystal capacitor Clca together with the liquid crystal layer 3 therebetween and the second sub pixel electrode 191b and the counter electrode 270 form a first liquid crystal capacitor The applied voltage is maintained even after the first and second thin film transistors Qa and Qb are turned off by forming the second liquid crystal capacitor Clcb together with the liquid crystal layer 3 therebetween.

The first and second sub-pixel electrodes 191a and 191b may overlap the sustain electrode line 125 to form the first and second storage capacitors Csta and Cstb.

The specific operation and the visibility improvement method of the liquid crystal display device according to the present embodiment follow the description with reference to FIG.

Next, a display device according to an embodiment of the present invention will be described with reference to FIGS. 7 to 9. FIG. The same reference numerals are given to the same constituent elements as those of the above-described embodiment, and the same explanations are omitted.

8A and 8B are plan views of one pixel of a display device according to an embodiment of the present invention, FIG. 9 is a cross-sectional view of a pixel of FIG. 8A Sectional view taken along the line IX-IX of the display device of Fig.

7, a display device according to an exemplary embodiment of the present invention includes a gate line 121 for transmitting a gate signal, a data line 171 for transmitting a data signal, a reference line for transmitting a reference voltage, The voltage line 178 includes a signal line and a pixel PX connected thereto.

Each pixel PX includes first and second sub-pixels PXa and PXb. The first sub-pixel PXa includes a first switching device Qa and a first liquid crystal capacitor Clca and the second sub-pixel PXb includes a second and a third switching devices Qa, Qb, Qc, And a second liquid crystal capacitor (Clca, Clcb).

The first switching device Qa and the second switching device Qb are connected to the gate line 121 and the data line 171 respectively and the third switching device Qc is connected to the output of the second switching device Qb Terminal and the reference voltage line 178, respectively.

The first switching element Qa and the second switching element Qb are three terminal elements such as a thin film transistor and the control terminal thereof is connected to the gate line 121 and the input terminal thereof is connected to the data line 171 The output terminal of the first switching device Qa is connected to the first liquid crystal capacitor Clca and the output terminal of the second switching device Qb is connected to the second liquid crystal capacitor Clcb and the third switching device Qc As shown in Fig.

The third switching element Qc is also a three terminal element such as a thin film transistor. The control terminal is connected to the gate line 121, the input terminal is connected to the second liquid crystal capacitor Clcb, (Not shown).

7, when a gate-on voltage Von is applied to the gate line 121, the first switching device Qa, the second switching device Qb, Then, the third switching element Qc is turned on. The data voltage applied to the data line 171 is applied to the first liquid crystal capacitor Clca and the second liquid crystal capacitor Clcb through the first switching device Qa and the second switching device Qb, The first liquid crystal capacitor Clca and the second liquid crystal capacitor Clcb are charged by the difference between the data voltage Vd and the common voltage Vcom. At this time, the same data voltage (Vd) is transferred to the first liquid crystal capacitor (Clcb) and the second liquid crystal capacitor (Clcb) through the first and second switching devices (Qa, Qb) The charging voltage becomes a partial pressure through the third switching element Qc. Accordingly, since the charging voltage of the second liquid crystal capacitor Clcb becomes smaller than the charging voltage of the first liquid crystal capacitor Clca, the luminance of the two sub-pixels PXa and Pxb can be changed. Therefore, by appropriately adjusting the voltage charged in the first liquid crystal capacitor Clca and the voltage charged in the second liquid crystal capacitor Clcb, the image viewed from the side can be made as close as possible to the image viewed from the front, Side visibility can be improved.

A specific structure of the liquid crystal display device according to the embodiment shown in FIG. 7 will now be described with reference to FIGS. 8A and 8B. FIG.

8A and 8B, the liquid crystal display according to the present embodiment includes a lower display panel 100 and an upper display panel 200 facing each other, a liquid crystal layer 3 interposed between the two display panels 100 and 200 And a pair of polarizers (not shown) attached to the outer surfaces of the display panels 100 and 200.

First, the lower display panel 100 will be described. A gate line 121 is positioned on the insulating substrate 110. The gate line 121 includes a first gate electrode 124a, a second gate electrode 124b, and a third gate electrode 124c.

The gate insulating film 140 is positioned on the gate line 121 and the first semiconductor 154a, the second semiconductor 154b and the third semiconductor 154c are positioned thereon.

A plurality of resistive contact members 163a, 165a, 163b, 165b, 163c, and 165c may be disposed on the first semiconductor 154a, the second semiconductor 154b, and the third semiconductor 154c.

A plurality of data lines 171 including a first source electrode 173a and a second source electrode 173b are formed on the resistive contact members 163a, 165a, 163b, 165b, 163c, and 165c and the gate insulating film 140, The data conductors 171, 173c, 175a, and 175c including the first drain electrode 175a, the second drain electrode 175b, the third source electrode 173a, and the third drain electrode 175c, and the reference voltage line 178, 175b, 175c, 178 are located.

The reference voltage line 178 may include two line bases 178a substantially parallel to the data line 171 and a connecting portion 178b connecting the two line bases 178a to each other. The delay of the signal flowing through the reference voltage line 178 can be prevented by connecting the two line portions 178a of the reference voltage line 178 to the connecting portion 178b. However, the shape of the reference voltage line 178 is not limited to this, and can be variously modified.

The first gate electrode 124a, the first source electrode 173a and the first drain electrode 175a together with the first semiconductor 154a form the first thin film transistor Qa and the second gate electrode 124b The second source electrode 173b and the second drain electrode 175b together with the second semiconductor 154b form the second thin film transistor Qb and the third gate electrode 124c, The second drain electrode 173c and the third drain electrode 175c may form the third thin film transistor Qc together with the third semiconductor 154c.

The passivation layer 180 may be located on portions of the data conductors 171, 173c, 175a, 175b, 175c, and 177 and exposed semiconductors 154a, 154b, and 154c. The passivation layer 180 may include a plurality of contact holes 185a and 185b that expose the first drain electrode 175a and the second drain electrode 175b.

The pixel electrode 191 including the first sub-pixel electrode 191a and the second sub-pixel electrodes 191a and 191b is located on the passivation layer 180. [

The pixel electrode 191 may include a first side parallel to the gate line 121 and a second side parallel to the data line 171. The first side parallel to the gate line 121 may be longer than the second side parallel to the data line 171. In this case, since the number of data lines 171 located on the display panel 300 can be reduced, the number of data driving circuit chips included in the data driver 500 can be reduced.

The first sub-pixel electrode 191a and the second sub-pixel electrode 191b may be adjacent to each other in the horizontal direction. Each of the first and second sub-pixel electrodes 191a and 191b may include a cross stripe portion 195 and a plurality of fine branches 199.

The first sub-pixel electrode 191a and the second sub-pixel electrode 191b are physically and electrically connected to the first drain electrode 175a and the second drain electrode 175b through contact holes 185a and 185b, respectively And a data voltage can be applied from the first drain electrode 175a and the second drain electrode 175b. At this time, a part of the data voltage applied to the second drain electrode 175b is divided through the third source electrode 173c so that the magnitude of the voltage applied to the second sub-pixel electrode 191b is smaller than that of the first sub-pixel electrode 191a May be less than the magnitude of the voltage applied to the gate.

The area of the second sub-pixel electrode 191b may be equal to or larger than the area of the first sub-pixel electrode 191a.

On the other hand, the voltage applied to the reference voltage line 178 may be greater than the common voltage Vcom, and the absolute value of the difference may be about 1V to about 4V.

The shielding member 220 and the color filter 230 may be disposed on the insulating substrate 210. [ At least one of the light shielding member 220 and the color filter 230 may be located on the lower panel 100.

The overcoat 250 may be disposed on the color filter 230 and the light shielding member 220, but the cover film 250 may be omitted.

A counter electrode 270 is formed on the cover film 250.

On both sides of the display panels 100 and 200, alignment films are formed and they may be vertical alignment films.

The image display method of the liquid crystal layer 3 including the liquid crystal molecules 31 and the pixel PX is similar to the above-described embodiment, and a detailed description thereof will be omitted.

8B, the display device according to an embodiment of the present invention is substantially the same as the embodiment shown in FIG. 8A described above, except that the gate lines 121 extend in the horizontal direction and the data lines 171 extend in the vertical direction And cross the gate line 121.

The side of the pixel electrode 191 which is substantially parallel to the side gate line 121 may be shorter than the side substantially parallel to the data line 171. The first sub-pixel electrode 191a and the second sub-pixel electrode 191b may be adjacent to each other in the vertical direction.

Next, a display device according to various embodiments of the present invention will be described with reference to FIGS. 10 to 12. FIG.

10, 11, and 12 are equivalent circuit diagrams of one pixel of a display device according to an embodiment of the present invention.

Referring to FIG. 10, a display device according to an embodiment of the present invention includes a signal line including first and second data lines 171a and 171b and a gate line 121, and a pixel PX connected thereto.

Each pixel PX includes first and second sub-pixels PXa and PXb. The first sub-pixel PXa includes a first switching device Qa, a first liquid crystal capacitor Clca and a first holding capacitor Csta. The second sub-pixel PXb includes a second switching device Qb, A second liquid crystal capacitor Clcb, and a second storage capacitor Cstb.

The first switching element Qa includes a control terminal connected to the gate line 121 and an input terminal connected to the first data line 171a. The output terminal of the first switching device Qa is connected to the first liquid crystal capacitor Clca and the first holding capacitor Csta.

The second switching element Qb includes a control terminal connected to the gate line 121 and an input terminal connected to the second data line 171b. The output terminal of the second switching device Qb is connected to the second liquid crystal capacitor Clcb and the second holding capacitor Cstb.

The first liquid crystal capacitor Clca and the second liquid crystal capacitor Clcb are connected to the data lines 171a and 171b through the first and second switching elements Qa and Qb connected to the data lines 171a and 171b, And receive different data voltages Vd.

Referring to FIG. 11, a display device according to the present embodiment includes a data line 171, a signal line including the first and second gate lines 121a and 121b, and a pixel PX connected thereto. Each pixel PX includes first and second sub-pixels PXa and PXb.

The first switching element Qa included in the first subpixel PXa includes a control terminal connected to the first gate line 121a and an input terminal connected to the data line 171. [ The output terminal of the first switching device Qa is connected to the first liquid crystal capacitor Clca and the first holding capacitor Csta.

The second switching element Qb includes a control terminal connected to the second gate line 121b and an input terminal connected to the data line 171. [ The output terminal of the second switching device Qb is connected to the second liquid crystal capacitor Clcb and the second holding capacitor Cstb.

The first liquid crystal capacitor Clca and the second liquid crystal capacitor Clcb are connected to the data lines 171 through the first and second switching devices Qa and Qb connected to the different gate lines 121a and 121b The different data voltages Vd for the input video signal IDAT can be supplied at different times.

12, a display device according to the present embodiment includes a signal line including a data line 171 and a gate line 121 and a pixel PX connected thereto. Each pixel PX may include a coupled capacitor Ccp connected between the first and second sub-pixels PXa and PXb and the two sub-pixels PXa and PXb.

The first subpixel PXa includes a switching element Q connected to the gate line 121 and the data line 171 and a first liquid crystal capacitor Clca and a first holding capacitor Csta connected to the switching element Q, The second sub-pixel PXb includes a second liquid crystal capacitor Clcb connected to the coupled capacitor Ccp.

The control terminal of the switching element Q is connected to the gate line 121. The input terminal of the switching element Q is connected to the data line 171. The output terminal of the switching element Q is connected to the first liquid crystal capacitor Clca, And the combined capacitor Ccp. The switching element Q transfers the data voltage Vd of the data line 171 to the first liquid crystal capacitor Clca and the coupled capacitor Ccp in accordance with the gate signal from the gate line 121, Can change the magnitude of this voltage and transmit it to the second liquid crystal capacitor Clcb. The voltage Va charged in the first liquid crystal capacitor Clca and the voltage Vb charged in the second liquid crystal capacitor Clcb may have the following relationship.

Vb = Va 占 [Ccp / (Ccp + Clcb)]

Where Ccp is the capacitance of the combined capacitor (Ccp), and Clcb is the capacitance of the second liquid crystal capacitor (Clcb). Therefore, the voltage Vb charged in the second liquid crystal capacitor Clcb can always be smaller than the voltage Va charged in the first liquid crystal capacitor Clca. The first liquid crystal capacitor Clca can improve the lateral visibility by adjusting the ratio of the charging voltage Va and the charging voltage Vb of the second liquid crystal capacitor Clcb by properly adjusting the electrostatic capacity of the coupled capacitor Ccp .

As described above, the first subpixel PXa and the second subpixel PXb of one pixel PX of the display device according to an embodiment of the present invention can display images according to different gamma curves by various methods And may display an image having the same brightness.

A display device according to an embodiment of the present invention will now be described with reference to FIGS.

FIGS. 13 and 14 are simplified circuit diagrams of a plurality of pixels of a display device according to an embodiment of the present invention, and FIGS. 15 and 16 are graphs respectively showing gamma curves of a display device according to an embodiment of the present invention .

13, the pixel PX located in one pixel column among the plurality of pixels PX is connected to the same data line Dj, D (j + 1), D (j + 2) through the switching element Q, , D (j + 3). 14, a pixel PX located in one pixel column among the plurality of pixels PX is connected to two different data lines Dj, D (j + 1), D (j + 1) through the switching element Q, j + 2), D (j + 3). According to an embodiment of the present invention, the pixel PX located on one pixel row may be connected to the same gate line Gi, G (i + 1), G (i + 2).

Each pixel PX displays one of the primary colors to realize color display (space division), or each pixel PX alternately displays a basic color (time division) The desired color can be recognized by the spatial and temporal sum. A plurality of adjacent pixels PX that display different basic colors can form one set (also referred to as a dot) together. One dot can display a white image.

The gate driver 400 is connected to the gate lines G1 to Gn and applies a gate signal Vg formed by a combination of the gate-on voltage Von and the gate-off voltage Voff to the gate lines G1 to Gn.

The memory 650 is connected to the signal controller 600 to store the gamma data for the gamma curve, and then outputs the gamma data to the signal controller 600. The gamma curve is a curve showing the luminance or transmittance with respect to the gradation of the input image signal IDAT, and can determine the gradation voltage or the reference gradation voltage based on the curve. The gamma data stored in the memory 650 may include gamma data for two or more different gamma curves.

For example, referring to FIG. 15, gamma data of a display device according to an exemplary embodiment of the present invention may include gamma data for a first gamma curve GH and a second gamma curve GL. Here, the brightness of the image according to the first gamma curve GH may be higher than or equal to the brightness of the image according to the second gamma curve GL. The first and second gamma curves GH and GL are designed so that the composite gamma curve at the front of the first and second gamma curves GH and GL best fits the display device, Gamma curve (for example, a gamma curve with a gamma value of 2.2) (Gf), and the synthetic gamma curve at the side can be adjusted to be as close as possible to the front gamma curve Gf.

Referring to FIG. 16, gamma data according to another embodiment of the present invention may include gamma data for at least three gamma curves different from each other. In particular, the gamma data according to an embodiment of the present invention may include gamma data for the first gamma curve GH, the second gamma curve GL, and the third gamma curve GM. Here, the luminance of the image according to the first gamma curve GH may be higher or equal to the luminance of the image according to the third gamma curve GM, and the luminance of the image according to the third gamma curve GM may be equal to or lower than the luminance of the second gamma curve GM. May be higher than or equal to the luminance of the image according to the luminance level (GL). The first to third gamma curves GH, GL and GM are set such that the composite gamma curve of the image displayed during one frame set matches the front gamma curve Gf determined to be best suited for the display device in order to improve lateral visibility The composite gamma curve at the side can be adjusted to be as close as possible to the front gamma curve Gf. At this time, the first to third gamma curves GH, GL, and GM may be selected so that the synthetic gamma curve does not have the inflexion point as close as possible to the front gamma curve Gf, thereby improving the display quality.

The memory 650 may be included in the signal controller 600 or the gray voltage generator 800 and may be included in the data driver 500 according to another embodiment of the present invention.

The gradation voltage generator 800 generates the total gradation voltage related to the transmittance of the pixel PX or a limited number of gradation voltages (referred to as a reference gradation voltage). (Reference) gradation voltage may have a positive value and a negative value with respect to the common voltage Vcom. The gradation voltage generator 800 receives the gamma data from the signal controller 600 and generates the (reference) gradation voltage based on the gamma data.

According to another embodiment of the present invention, the gradation voltage generator 800 may be included in the data driver 500.

The data driver 500 is connected to the data lines D1 to Dm and selects the gradation voltage from the gradation voltage generator 800 and applies the gradation voltage to the data lines D1 to Dm as the data voltage Vd. However, when the gradation voltage generator 800 does not provide all of the gradation voltages but only provides a limited number of reference gradation voltages, the data driver 500 divides the reference gradation voltages to generate gradation voltages for all gradations And the data voltage Vd may be selected from these.

The signal controller 600 controls operations of the gate driver 400 and the data driver 500 and the like. The signal controller 600 may further include a frame memory 660 that can store the input image signal IDAT in units of frames.

The display device according to another embodiment of the present invention may further include a backlight (not shown) for providing light to the display panel 300.

A display driving method of such a display apparatus will be described below.

The signal control unit 600 receives an input video signal IDAT and an input control signal ICON for controlling the display thereof. The input image signal IDAT contains the luminance information of each pixel PX and the luminance has a predetermined number of gray levels. Examples of the input control signal ICON include a vertical synchronization signal, a horizontal synchronization signal, a main clock signal, and a data enable signal.

The signal controller 600 processes the input video signal IDAT based on the input video signal IDAT and the input control signal ICON and converts the input video signal IDAT into an output video signal DAT and outputs the gate control signal CONT1, The control signal CONT2 and the gamma control signal CONT3. The signal controller 600 outputs the gate control signal CONT1 to the gate driver 400 and outputs the data control signal CONT2 and the output video signal DAT to the data driver 500. The gamma control signal CONT3, And outputs it to the voltage generator 800. The data control signal CONT2 may further include an inversion signal for inverting the polarity of the data voltage Vd (referred to as the polarity of the data voltage) with respect to the common voltage Vcom. The gamma control signal CONT3 includes gamma data stored in the memory 650. [

The gradation voltage generator 800 generates a gradation voltage or a limited number of reference gradation voltages according to the gamma control signal CONT3 and outputs the gradation voltage to the data driver 500. [ The gradation voltages may be provided for different gamma curves, and a gradation voltage may be generated for the selected gamma curve through a separate selection process.

The data driver 500 receives the digital video signal DAT for the pixel PX of one row in accordance with the data control signal CONT2 from the signal controller 600 and outputs the digital video signal DAT corresponding to each digital video signal DAT Converts the digital video signal DAT to the analog data voltage Vd by selecting the gradation voltage, and applies it to the corresponding data line D1-Dm.

A frame frequency (also referred to as an input frequency or a gamma frequency) at which the data driver 500 outputs a data voltage Vd to the data lines D1 to Dm and displays one image in each pixel PX is an input video signal (Also referred to as an output frequency) in units of two or more consecutive frames (referred to as a frame set) for displaying an image of the IDAT. Specifically, the image frequency may be 1 / n (n is a natural number of 2 or more) of the frame frequency. For example, when the frame frequency is 120 Hz, the image frequency may be 60 Hz, and when the frame frequency is 240 Hz, the image frequency may be 60 Hz, 80 Hz, 120 Hz, and the like.

The gate driver 400 applies a gate-on voltage Von to the gate lines G1-Gn in accordance with the gate control signal CONT1 from the signal controller 600 and applies the gate-on voltage Von to the gate lines G1- . Then, the data voltage Vd applied to the data lines D1-Dm is applied to the corresponding pixel PX through the turned-on switching element. When the data voltage Vd is applied to the pixel PX, the pixel PX can display the luminance corresponding to the data voltage Vd through the various optical conversion elements. For example, in the case of a liquid crystal display device, the degree of tilt of liquid crystal molecules in the liquid crystal layer can be controlled to adjust the polarization of light to display the luminance corresponding to the gradation of the input image signal IDAT.

This process is repeated in units of one horizontal period (also referred to as "1H ", which is the same as one cycle of the horizontal synchronizing signal Hsync and the data enable signal DE), so that all the gate lines G1 to Gn On voltage Von is sequentially applied to all the pixels PX and the data voltage Vd is applied to all the pixels PX to display an image of one frame.

According to one embodiment of the present invention, a pixel PX can display an image by receiving a data voltage (Vd) according to different gamma curves during a plurality of frames included in one frame set, which is referred to as time division driving . If the gamma data includes two or more gamma curves as shown in FIGS. 15 and 16, the image displayed during one frame set is the first gamma having the largest luminance for the intermediate gray level, which is not the lowest gray level and the highest gray level, The image corresponding to the curve GH and the second gamma curve GL having the lowest luminance with respect to one gradation may be included.

When one pixel PX includes two sub-pixels PXa and PXb, the spatial division driving and the time division driving are applied together to generate a signal for one input image signal IDAT through the two sub-pixels PXa and PXb during one frame, It is possible to display an image according to different gamma curves and display an image according to a gamma curve in which each of the subpixels PXa and PXb is continuous in a continuous frame. Thus, for the two sub-pixels PXa and PXb, the composite gamma curve at the side during one frame set can be made as close to the front gamma curve Gf as possible, thereby improving the side viewability.

When one frame ends, the next frame starts and the state of the inverted signal included in the data control signal CONT2 is controlled so that the polarity of the data voltage Vd applied to each pixel PX is opposite to the polarity of the previous frame (Referred to as frame inversion). It is possible to invert the polarity of the data voltage Vd applied to all the pixels PX for every one or more frames when the frame is inverted. The polarity of the data voltage Vd flowing through one data line D1-Dm periodically changes or the data voltage Vd applied to the data lines D1-Dm of one pixel line Vd may have different polarities.

D (j + 1), D (j + 2), and D (j + 1) when the polarities of the data voltages Vd applied to the data lines D1- 3) have different polarities of the data voltage Vd. In this case, according to the structure shown in Fig. 13, the polarity of the data voltage Vd of the pixel PX located in one pixel row is the same and the polarity of the data voltage Vd of the pixel PX located on one pixel row is positive (+) And negative (-) can be alternately arranged. On the other hand, according to the structure shown in FIG. 14, the polarity of the data voltage Vd of the pixel PX located in one pixel column can be alternately arranged in the column direction in the positive and negative directions.

Various embodiments of the driving method of the display device according to the above-described various embodiments will be described with reference to Figs. 17 to 29. Fig.

Fig. 17 is a diagram showing the polarities of the luminance and data voltages of a plurality of pixels of the display device according to one embodiment of the present invention in frame order, and Figs. 18A, 18B, 18C, 18D, 18f are diagrams showing the luminance of one pixel of the display device according to one embodiment of the present invention in frame order, and Figs. 19 to 29 are diagrams showing the luminance of one pixel of the display device according to one embodiment of the present invention, And the polarity of the luminance and the data voltage in accordance with the frame order.

The display device according to an embodiment of the present invention can improve lateral visibility by using the first and second gamma curves GH and GL described above. However, it is not limited thereto, and three or more different gamma curves may be used.

17, a display device according to an embodiment of the present invention includes a plurality of dots (Dot1, Dot2, Dot3, Dot4) arranged in a matrix form, and each dot (Dot1, Dot2, Dot3, Dot4) Includes a plurality of pixels PX1, PX2, and PX3 that respectively display different basic colors such as red, green, and blue. The first pixel PX1, the second pixel PX2, and the third pixel PX3 included in one dot Dot1-Dot4 may represent different three primary colors, for example, red, green, and blue, respectively. The plurality of pixels PX1, PX2, and PX3 included in each dot (Dot1 to Dot4) can be arranged in the row direction or the column direction and can display images corresponding to different input video signals IDAT .

Each dot (Dot1-Dot4) can be driven by setting two or more consecutive frames as one frame set. FIG. 17 shows an example of driving two frames as one frame set. The first input image signal IDAT1 is displayed with different luminance levels by applying different gamma curves during the first frame set including the two consecutive frames 1F and 2F, For the next second input video signal IDAT2, an image of different luminance is applied using different gamma curves in the second frame set, which is located after the first frame set and includes consecutive two frames 3F and 4F can do.

Referring to one pixel PX1, PX2 and PX3, one of two frames included in one frame set displays an image (referred to as a first image H) according to the first gamma curve GH, (Referred to as a second image L) according to the second gamma curve GL. According to such a time-divisional drive, since images corresponding to different gamma curves are displayed in consecutive frames, the composite gamma curve at these sides can be made as close as possible to the front gamma curve Gf, thereby improving the lateral visibility. In addition, since it is not necessary to divide one pixel PX, the transmittance can also be improved.

Figs. 18A to 18F show various examples of images in which one pixel PX1, PX2, PX3 displays according to time-division driving during two frame sets.

18A, each of the pixels PX1, PX2, and PX3 receives the first image H in the first frame 1F, which is the first frame of the frame set for the first input video signal IDAT1, (L) is displayed in the second frame (2F), which is the second frame, in the third frame (3F), which is the first frame in the frame set for the next second input video signal (IDAT2) 2 image L and displays the first image H in the fourth frame 4F, which is the second frame. Then, during the next two frame sets, the pixels PX1, PX2, and PX3 may be displayed in the same manner as the first through fourth frames 1F through 4F, One image H, and the second image L in that order.

If the order of displaying the first image (H) and the second image (L) in the continuous frame set is reversed, the second image (L) having a low luminance is displayed in successive frames. Can be compensated for. Also, if the order of displaying the first image H and the second image L in the successive frame set is reversed, the first image H having a high luminance can be displayed in successive frames as well. Therefore, when displaying a low-luminance image and then displaying a high-luminance image, a sufficient high gradation can be displayed by compensating the response speed of the liquid crystal molecules.

18B, each of the pixels PX1, PX2, and PX3 receives the first image H in the first frame 1F, which is the first frame of the frame set for the first input video signal IDAT1, (L) is displayed in the second frame (2F), which is the second frame, in the third frame (3F) which is the first frame in the frame set for the next second input video signal (IDAT2) 1 image H and the second image L in the second frame, that is, the fourth frame 4F. Thereafter, the image can be displayed in the same manner as the first to fourth frames 1F to 4F even during the frame set.

18C, 18D and 18E, the pixel PX according to the present embodiment can display an image for one input video signal IDAT with three consecutive frames as one frame set. For example, an image for the first input video signal IDAT1 is displayed in three consecutive frames 1F, 2F and 3F and a second input video signal IDAT2 is displayed for the next three consecutive frames 4F, 5F and 6F. Can be displayed.

More specifically, according to the embodiment shown in FIG. 18C, the first and fourth frames 1F and 4F, which are the first frames among the three frames included in one frame set, of the pixels PX1, PX2, and PX3, It is possible to display the image H and display the second image L during the remaining two frames 2F, 3F, 5F and 6F. At this time, since two consecutive frames display the second image L having low brightness, the slow response speed of the liquid crystal molecules of the liquid crystal display device can be compensated for, thereby further improving the lateral visibility, as described above.

According to the embodiment shown in FIG. 18D, the order of displaying the first image H and the second image L in two successive frame sets of the pixels PX1, PX2, and PX3 may be opposite to each other. Accordingly, the second image L having a low luminance can be displayed continuously as much as possible, and the first image H having a high luminance can be displayed in two consecutive frames.

According to the embodiment shown in FIG. 18E, the first image H and the second image L may be displayed in the same order in two successive frame sets. For example, the first frame 1F, 4F and the last frame 3F, 6F of the three frames included in one frame set represent the second image L and the second frame 2F, The image H can be displayed. At this time, the two consecutive frames positioned between two neighboring frame sets continuously display the second image L having low brightness, so that the slow response speed of the liquid crystal molecules of the liquid crystal display device can be compensated to improve the lateral visibility . Also, since the first image H having a high luminance can be continuously displayed in two consecutive frames, a slow response speed of the liquid crystal molecules can be compensated for when displaying an image with a low luminance and a high luminance.

According to the embodiment shown in FIG. 18F, each pixel PX1, PX2, and PX3 can display an image for one input video signal IDAT with four consecutive frames as one frame set. For example, in the four consecutive frames 1F, 2F, 3F and 4F, an image for the first input video signal IDAT1 is displayed, and in the subsequent four frames 5F, 6F, 7F and 8F, An image for the video signal IDAT2 can be displayed. 18F, the first frame 1F, 5F of the four frames included in each frame set displays the first image H and the remaining three frames 2F, 3F, 4F, 6F, 7F, 8F. Can display the second image (L). At this time, since three consecutive frames display the second image L having a low luminance, the slow response speed of the liquid crystal molecules of the liquid crystal display device can be compensated to further improve the lateral visibility.

18F, the sequence of displaying the first image H and the second image L in the successive frame set is reversed to display the second image L in six consecutive frames, The first image H may be displayed in two frames.

In addition, an image for one input video signal IDAT may be displayed with five or more consecutive frames as one frame set. At this time, frames of the second image L having a low luminance are consecutively maximized in one frame set, thereby sufficiently expressing the low gradation and further improving the side visibility.

According to one embodiment of the present invention, in order to maximize the visibility, it is necessary that the falling response speed of the liquid crystal molecules is fast. For example, when the image is changed from high luminance to low luminance, the falling response speed of the liquid crystal molecules when the luminance of the image changes from 99% to 1% of the luminance difference is less than 4.17 ms when the frame frequency is 240 Hz, It can be less than 8.3ms when the frame frequency is 120Hz.

Referring again to FIG. 17, FIG. 17 shows an example in which each pixel PX1, PX2, PX3 displays an image in the same order as the embodiment shown in FIG. 18A.

According to the embodiment of the present invention, the gamma curves of the images displayed by the neighboring pixels PX1, PX2 and PX3 in the frames 1F, 2F, 3F and 4F are different from each other. That is, the image along the first gamma curve GH and the image along the second gamma curve GL can be simultaneously displayed during one frame 1F, 2F, 3F, and 4F. Therefore, according to the embodiment of the present invention, display defects such as flicker due to the difference in luminance according to different gamma curves can be eliminated, compared with a case where each frame displays an image according to one gamma curve.

According to another embodiment of the present invention, the gamma curves of the images displayed by the pixels PX1, PX2 and PX3 in the respective frames 1F, 2F, 3F and 4F correspond to the two or more pixels PX1, PX2 and PX3 Can be changed.

For example, referring to FIG. 19, the driving method according to the present embodiment is substantially the same as the embodiment shown in FIG. 17, but three neighboring pixels PX1, PX2 and PX3 display an image following the same gamma curve , Different gamma curves may be followed for each of the three pixels PX1, PX2, and PX3. That is, one dot (Dot1-Dot4) displays an image along the first gamma curve (GH) and the neighboring dots (Dot1-Dot4) displays an image along the second gamma curve (GL). The gamma curve applied to each of the two pixels PX1, PX2, and PX3 may be changed, as shown in FIG.

17, 19 to 23, the display device according to an embodiment of the present invention can follow the polarity inversion driving method as in the embodiment shown in FIG. 14 described above. According to this, the polarities of the data voltages Vd (hereinafter referred to as the polarities of the pixels PX1, PX2 and PX3) applied to the pixels PX1, PX2 and PX3 neighboring in the row direction and the column direction in the same frame are opposite to each other Lt; / RTI >

In addition, the polarity of the data voltage Vd applied to all the pixels PX1, PX2 and PX3 can be inverted every frame. 17, if the polarities of the pixels PX1, PX2 and PX3 displaying the first image H in the first frame set 1F and 2F are positive (+), the second frame set The polarity of the pixels PX1, PX2, and PX3 that display the first image H in the first, second, third, and fourth frames may be negative. Likewise, if the polarities of the pixels PX1, PX2 and PX3 displaying the second image L in the first frame set 1F and 2F are negative, The polarity of the pixels PX1, PX2, and PX3 that indicate the pixels L, L may be positive.

20 is almost the same as the embodiment shown in FIG. 17, but each pixel PX1, PX2, and PX3 can follow a video display procedure like the embodiment shown in FIG. 18B described above. That is, the pixels PX1, PX2, and PX3 can alternately display the first image H and the second image L on a frame-by-frame basis.

The embodiment shown in FIG. 21 is almost the same as the embodiment shown in FIG. 19, but each pixel PX1, PX2, and PX3 can follow the same video display procedure as the embodiment shown in FIG. 18B described above. That is, the pixels PX1, PX2, and PX3 can alternately display the first image H and the second image L on a frame-by-frame basis.

Referring to FIG. 22, the present embodiment is almost the same as the embodiment shown in FIG. 17, but the polarity of the data voltage Vd applied to all the pixels PX1, PX2, and PX3 can be reversed for each two frames. 22, the polarities of the pixels PX1, PX2 and PX3 displaying the first image H are changed every frame and the pixels PX1, PX2 and PX3 displaying the second image L are changed. PX3) is changed every frame. Therefore, as compared with the embodiment shown in FIG. 17, since the polarities of the first image H or the second image L according to each gamma curve are changed for each frame, the polarity of the image according to each gamma curve It is possible to minimize the flicker due to the luminance change and to eliminate the afterimage.

23, this embodiment is almost the same as the embodiment shown in FIG. 22, but each pixel PX1, PX2, and PX3 can display an image in the same order as the embodiment shown in FIG. 18B described above . The polarity of the data voltage Vd applied to all the pixels PX1, PX2, and PX3 may be inverted every frame or inverted every four frames. When the polarity of the data voltage Vd applied to all the pixels PX1, PX2 and PX3 is inverted every four frames, the polarities of the first image H or the second image L according to the respective gamma curves are changed for each frame It is possible to minimize the flicker due to the luminance change caused by the polarity change of the image according to each gamma curve.

Referring to FIGS. 24 and 25, the present embodiment is mostly the same as the embodiment shown in FIG. 17, but the polarities of the neighboring pixels PX1, PX2 and PX3 are different from each other. The display device according to an embodiment of the present invention can follow the polarity inversion driving method as in the embodiment shown in FIG. 13 described above. According to this, the polarities of the pixels PX1, PX2 and PX3 neighboring in the row direction in the same frame are opposite to each other, but the polarities of the neighboring pixels PX1, PX2 and PX3 in the column direction may be the same. Therefore, according to the embodiment shown in Figs. 24 and 25, among the pixels PX1, PX2 and PX3 displaying the first image H in each of the frames 1F, 2F, 3F and 4F, The number of pixels having a negative polarity is substantially equal to the number of pixels having a negative polarity and a pixel having a positive polarity among the pixels PX1, PX2, and PX3 displaying the second image L has a negative polarity. May be substantially the same. A pixel having a positive polarity and a pixel having a negative polarity are adjacent to each other in the column direction among the pixels representing the first image H and a polarity is positive + ) And a pixel whose polarity is negative (-) are adjacent to each other in the column direction, so that there is a polarity cancellation effect.

According to the embodiment shown in FIGS. 24 and 25, the luminance of the pixel in which the first image H is positive, the luminance of the pixel in which the first image H is negative, the luminance of the second image L 2F, 3F, and 4F are different from each other even if the luminance of the pixel having the positive (+) and the luminance of the pixel having the positive (-) is different from the luminance of the pixel having the positive The luminance differences of the pixels PX1, PX2 and PX3 to be displayed can be offset from each other and the luminance differences of the pixels PX1, PX2 and PX3 that display the second image L can also cancel each other. Therefore, the flicker due to the difference in luminance according to the different gamma curves can be eliminated without substantially changing the luminance according to the frame for the entire pixel PX.

Referring to FIG. 25, when a certain pattern moves on the screen according to time, the pattern may be displayed by dots (Dot1-Dot4) at different positions in each frame set. Fig. 25 shows an example in which a moving pattern moves by one dot when one frame set elapses.

Specifically, one moving pattern is represented by the first dot Dot1 and the third dot Dot3 in the first frame set 1F and 2F and the one dot is moved in the second frame set 3F and 4F The second dot (Dot2) and the fourth dot (Dot4). For example, the moving pattern is represented by the first pattern image A1 in the first frame 1F, the second pattern image A1 'in the second frame 2F, and the moving pattern is displayed in the third frame 3F May be displayed as the third pattern image A2 and as the fourth pattern image A2 'in the fourth frame 4F. Here, the first and second pattern images A1 and A1 'correspond to the same first input image signal IDAT1 and follow different gamma curves, and the third and fourth pattern images A2 and A2' 2 input video signal IDAT2 and can follow different gamma curves.

The polarity of the first image H of the pixels PX1, PX2 and PX3 displaying the first pattern image A1 in the first frame 1F is the same as the polarity of the third pattern image A2 in the third frame 3F And the polarity of the first image H of the pixels PX1, PX2, and PX3 representing the second image L is the same. The polarity of the first image H of the pixels PX1, PX2 and PX3 displaying the second pattern image A1 'in the second frame 2F is changed from the fourth pattern 4F to the fourth pattern image A2 And the polarity of the first image H of the pixels PX1, PX2, and PX3 that display the second image L '. Therefore, the polarities of the pixels PX1, PX2, and PX3 representing the pattern moving by one dot for each frame set are offset from each other, so that the vertical line of the moving pattern is not recognized. 25, even when the moving pattern is shifted by two dots (Dot1-Dot4) for each frame set, display defects such as vertical stripes can be eliminated by the polarity cancellation effect as described above.

Referring to FIG. 26, this embodiment is mostly the same as the embodiment shown in FIG. 23, but the polarity arrangement of the neighboring pixels PX1, PX2, and PX3 is different. The display device according to an embodiment of the present invention can follow the polarity inversion driving method as in the embodiment shown in FIG. 13 described above. According to this, the polarities of the pixels PX1, PX2 and PX3 neighboring in the row direction in the same frame are opposite to each other, but the polarities of the neighboring pixels PX1, PX2 and PX3 in the column direction may be the same. Therefore, according to the embodiment shown in FIG. 26, among the pixels PX1, PX2 and PX3 displaying the first image H in each of the frames 1F, 2F, 3F and 4F, The pixels PX1, PX2 and PX3 displaying the second image L are substantially equal in number to the pixels whose polarities are positive and polarities of the pixels PX1, The number may be substantially the same. A pixel having a positive polarity and a pixel having a negative polarity are adjacent to each other in the column direction among the pixels representing the first image H and a polarity is positive + ) And a pixel whose polarity is negative (-) are adjacent to each other in the column direction, so that there is a polarity cancellation effect.

26, the luminance of the pixel in which the first image H is positive, the luminance of the pixel in which the first image H is negative, and the luminance of the pixel in which the second image L is positive (1F, 2F, 3F, 4F) for displaying the first image (H) in each frame (1F, 2F, 3F, 4F) even if the luminance of the pixel in which the first image The brightness of the pixels PX1, PX2, and PX3 that display the second image L can be offset from each other. Therefore, the flicker due to the difference in luminance according to the different gamma curves can be eliminated without substantially changing the luminance according to the frame for the entire pixel PX.

Referring to FIG. 27, this embodiment is almost the same as the embodiment shown in FIG. 26, but the polarity inversion form of all the pixels PX1, PX2 and PX3 according to the frame may be different.

According to the embodiment shown in FIG. 27, the polarities of the pixels PX1, PX2 and PX3 are inverted for each frame in each frame set, but the order of polarity inversion may be reversed between two adjacent frame sets. For example, the polarity of the first pixel PX1 of the first dot Dot1 is positive in the first frame 1F of the first frame set, negative in the second frame 2F, (-) in the third frame 3F of the second frame set, and positive (+) in the fourth frame 4F. The polarity of the second pixel PX2 of the first dot Dot1 is negative in the first frame 1F of the first frame set, positive in the second frame 2F, (+) In the third frame 3F of the set, and negative (-) in the fourth frame 4F.

In the embodiment shown in FIG. 27, a pattern moving by one dot at each elapse of a set of frames as in the embodiment shown in FIG. 25 described above is referred to as displaying the first pattern image A1 of the first frame 1F The polarity of the first image H of the pixels PX1, PX2 and PX3 is the same as the polarity of the first image H of the pixels PX1, PX2 and PX3 representing the fourth pattern image A2 'of the fourth frame 4F ), And the same is true for the second image L. The polarity of the first image H of the pixels PX1, PX2 and PX3 displaying the second pattern image A1 'of the second frame 2F is the polarity of the third pattern image A2 of the third frame 3F And the polarity of the first image H of the pixels PX1, PX2, and PX3 representing the second image L is the same. Therefore, the polarities of the pixels PX1, PX2, and PX3 representing the pattern moving by one dot for each frame set are offset from each other, so that the vertical line of the moving pattern is not recognized. 27, even when the moving pattern moves by two dots (Dot1-Dot4) for each frame set, the vertical stripes may not be visible due to the polarity cancellation effect as described above.

28 to 33, the method of driving the display device according to the present embodiment is the same as the method of driving the display device according to the above-described various embodiments, but when a pixel PX is driven by two or more Pixel. 28 to 33 show an example in which each pixel PX1, PX2, PX3 includes a first sub-pixel PXa and a second sub-pixel PXb.

The subpixels PXa and PXb included in one pixel PX may display images of different gamma curves or may display images of the same luminance.

Referring to Fig. 28, the display device according to the present embodiment can be driven in the same manner as the embodiment shown in Fig. 17 described above. Specifically, the driving method of each of the pixels PX1, PX2 and PX3 may be the same as that of the embodiment shown in Figs. 17 and 19 to 27, and the driving method of each pixel PX1, PX2 and PX3, The pixel PXa and the second sub-pixel PXb can receive the data voltage Vd of the same polarity. 28 shows an example in which the first subpixel PXa and the second subpixel PXb display different images on the same gamma curve.

28, according to another embodiment of the present invention, the first and second subpixels PXa and PXb of one pixel PX1, PX2, and PX3 can display images according to different gamma curves .

For example, referring to FIG. 29, when the first subpixel PXa of the pixel PX displaying the first image H in FIG. 28 displays the first image H, the second subpixel PXb Can display the third image M or the second image L according to the third gamma curve GM shown in Fig. The first subpixel PXa of the pixel PX that has displayed the first image H in FIG. 28 displays the third image M and the second subpixel PXb The first image H may be displayed.

31, a pixel PX in which the first and second subpixels PXa and PXb display the first image H and a first subpixel PXa display the second image L And the pixels PX for displaying the third image M may be alternately arranged in the row direction or the column direction in the second sub-pixel PXb.

32 is a diagram showing the relationship between the first and second subpixels (PXa and PXb) in the pixel PX including the first and second subpixels PXa and PXb, which represent the second image L and the third image M, PXa, and PXb are switched with each other.

33, a first subpixel PXa displays a first image H and a second subpixel PXb includes a pixel PX displaying a third image M and a second subpixel PXb, PXa may display the second image L and the second subpixel PXb may display the third image M by alternately arranging the pixels PX in the row direction or the column direction. According to another embodiment of the present invention, the display device can display images according to four or more gamma curves. In this case, in FIG. 33, the subpixels PXa and PXb of two pixels PX neighboring in the row direction or column direction May follow different gamma curves.

In the embodiments shown in FIGS. 28 to 33, the gamma curves of the images of the first and second sub-pixels PXa and PXb included in the respective pixels PX may be interchanged. For example, in FIG. 33, when the first subpixel PXa of one pixel PX displays the first image H and the second subpixel PXb displays the third image M, The first subpixel PXa of another pixel PX adjacent to the pixel PX in the row or column direction displays the third image M and the second subpixel PXb displays the second image L Can be displayed. Also in this case, the third image M displayed by the sub-pixels PXa and PXb of the two pixels PX may follow different gamma curves.

In addition, the first subpixel PXa and the second subpixel PXb can display an image composed of various combinations of images according to three or more gamma curves in order to improve lateral visibility. 28 to 33, the two subpixels PXa and PXb of one pixel PX1, PX2 and PX3 are shown to display images of the same polarity. However, the present invention is not limited to this, The subpixels PXa and PXb of one pixel PX1, PX2, and PX3 may display images having different polarities as in the example.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

300: display panel 191: pixel electrode
400: Gate driver 500: Data driver
600: signal controller 650: memory
660: frame memory 800: gradation voltage generator

Claims (40)

A display device including a plurality of pixels that display an image in units of frames and include neighboring first and second pixels,
Storing gamma data for two or more gamma curves in a memory,
Generating a gradation voltage based on the gamma data,
Receiving an input video signal from the outside and converting the input video signal to a data voltage using the gradation voltage, and
Wherein each of the first pixel and the second pixel receives the data voltage and displays an image corresponding to one input image signal during a first set of frames including two or more consecutive frames
Lt; / RTI >
Wherein the images displayed by the first pixel and the second pixel during the first set of frames include images along different gamma curves,
A gamma curve of an image displayed by the first pixel is different from a gamma curve of an image displayed by the second pixel during one frame,
Wherein an image displayed by two pixels neighboring to each other and representing the same color among the plurality of pixels has a gamma curve
A method of driving a display device. The method of claim 1,
Wherein the image displayed by the first pixel during the first set of frames comprises a first image along a first gamma curve and a second image along a second gamma curve,
The luminance of the first image is not lower than the luminance of the second image,
Wherein the second image for the first pixel is displayed in two consecutive frames
A method of driving a display device. 3. The method of claim 2,
The first image and the second image displayed by the first pixel in the first frame set and the first image and the first image displayed by the first pixel in a second frame set continuing to the first frame set, And the order of the second images are opposite to each other. 4. The method of claim 3,
Wherein polarities of the data voltages applied to two neighboring data lines of the plurality of data lines are opposite to each other. 5. The method of claim 4,
And pixels arranged in a pixel column direction among the plurality of pixels are alternately connected to two different data lines among the plurality of data lines. The method of claim 5,
And the polarity of the data voltage applied to the plurality of pixels is inverted every frame. The method of claim 5,
Wherein a polarity of the data voltage applied to the plurality of pixels is inverted for each of two or more frames. 5. The method of claim 4,
And pixels arranged in the pixel column direction among the plurality of pixels are connected to the same data line among the plurality of data lines. 9. The method of claim 8,
And the polarity of the data voltage applied to the plurality of pixels is inverted every frame. 9. The method of claim 8,
Wherein a polarity of the data voltage applied to the plurality of pixels is inverted for each of two or more frames. The method of claim 1,
Wherein the image displayed by the first pixel during the first set of frames comprises a first image along a first gamma curve and a second image along a second gamma curve,
The luminance of the first image is not lower than the luminance of the second image,
Wherein the first image and the second image with respect to the first pixel are alternately displayed for each frame
A method of driving a display device. 12. The method of claim 11,
Wherein polarities of the data voltages applied to two neighboring data lines of the plurality of data lines are opposite to each other. The method of claim 12,
And pixels arranged in a pixel column direction among the plurality of pixels are alternately connected to two different data lines among the plurality of data lines. The method of claim 13,
And the polarity of the data voltage applied to the plurality of pixels is inverted every frame. The method of claim 13,
Wherein a polarity of the data voltage applied to the plurality of pixels is inverted for each of two or more frames. The method of claim 12,
And pixels arranged in the pixel column direction among the plurality of pixels are connected to the same data line among the plurality of data lines. 17. The method of claim 16,
And the polarity of the data voltage applied to the plurality of pixels is inverted every frame. 17. The method of claim 16,
Wherein a polarity of the data voltage applied to the plurality of pixels is inverted for each of two or more frames. The method of claim 18,
Wherein the polarity arrangement order of the data voltages applied to the first pixel in the first frame set is opposite to the polarity arrangement order of the data voltages applied to the first pixel in a second frame set subsequent to the first frame set And a driving method of the display device. The method of claim 1,
Wherein each of the first pixel and the second pixel includes a first sub-pixel and a second sub-pixel. A memory for storing gamma data for two or more gamma curves,
A gradation voltage generator for generating a gradation voltage based on the gamma data,
A signal controller for receiving an input video signal from outside,
A data driver for receiving the input video signal from the signal controller and converting the input video signal to a data voltage using the gray scale voltage,
A display panel including a plurality of data lines for transmitting the data voltages, and a plurality of pixels for receiving the data voltages and displaying images on a frame basis,
/ RTI >
Wherein the plurality of pixels include a first pixel and a second pixel that are adjacent to each other and display an image corresponding to each input video signal,
Wherein each of the first pixel and the second pixel displays an image corresponding to one input image signal during a first set of frames including two or more consecutive frames,
Wherein the images displayed by the first pixel and the second pixel during the first set of frames include images along different gamma curves,
A gamma curve of an image displayed by the first pixel is different from a gamma curve of an image displayed by the second pixel during one frame,
Wherein an image displayed by two pixels neighboring to each other and representing the same color among the plurality of pixels has a gamma curve
Display device. 22. The method of claim 21,
Wherein the image displayed by the first pixel during the first set of frames comprises a first image along a first gamma curve and a second image along a second gamma curve,
The luminance of the first image is not lower than the luminance of the second image,
Wherein the second image for the first pixel is displayed in two consecutive frames
Display device. The method of claim 22,
The first image and the second image displayed by the first pixel in the first frame set and the first image and the first image displayed by the first pixel in a second frame set continuing to the first frame set, Wherein the order of the second images is opposite to each other. 24. The method of claim 23,
Wherein polarities of the data voltages applied to two neighboring data lines of the plurality of data lines are opposite to each other. 25. The method of claim 24,
And pixels arranged in a pixel column direction among the plurality of pixels are alternately connected to two different data lines among the plurality of data lines. 26. The method of claim 25,
Wherein polarities of the data voltages applied to the plurality of pixels are inverted every frame. 26. The method of claim 25,
Wherein a polarity of the data voltage applied to the plurality of pixels is inverted every two or more frames. 25. The method of claim 24,
And pixels arranged in the pixel column direction among the plurality of pixels are connected to the same data line among the plurality of data lines. 29. The method of claim 28,
Wherein polarities of the data voltages applied to the plurality of pixels are inverted every frame. 29. The method of claim 28,
Wherein a polarity of the data voltage applied to the plurality of pixels is inverted every two or more frames. 22. The method of claim 21,
Wherein the image displayed by the first pixel during the first set of frames comprises a first image along a first gamma curve and a second image along a second gamma curve,
The luminance of the first image is not lower than the luminance of the second image,
Wherein the first image and the second image with respect to the first pixel are alternately displayed for each frame
Display device. 32. The method of claim 31,
Wherein polarities of the data voltages applied to two neighboring data lines of the plurality of data lines are opposite to each other. 32. The method of claim 32,
And pixels arranged in a pixel column direction among the plurality of pixels are alternately connected to two different data lines among the plurality of data lines. 34. The method of claim 33,
Wherein polarities of the data voltages applied to the plurality of pixels are inverted every frame. 34. The method of claim 33,
Wherein a polarity of the data voltage applied to the plurality of pixels is inverted every two or more frames. 32. The method of claim 32,
And pixels arranged in the pixel column direction among the plurality of pixels are connected to the same data line among the plurality of data lines. 37. The method of claim 36,
Wherein polarities of the data voltages applied to the plurality of pixels are inverted every frame. 37. The method of claim 36,
Wherein a polarity of the data voltage applied to the plurality of pixels is inverted every two or more frames. 39. The method of claim 38,
Wherein the polarity arrangement order of the data voltages applied to the first pixel in the first frame set is opposite to the polarity arrangement order of the data voltages applied to the first pixel in a second frame set subsequent to the first frame set / RTI > 22. The method of claim 21,
Wherein each of the first pixel and the second pixel includes a first sub-pixel and a second sub-pixel.

Images