Display apparatus and method of driving the same

This application claims priority under 35 U.S.C. § 119 from and the benefit of Korean Patent Application No. 10-2015-0133849 filed on Sep. 22, 2015, which is hereby incorporated by reference for all purposes as if fully set forth herein.

Exemplary embodiments of the inventive concept relate to a display apparatus and a method of driving the display apparatus. More particularly, exemplary embodiments of the inventive concept relate to a display apparatus and a method of driving the display apparatus for high display quality.

A liquid crystal display (LCD) panel may include a thin film transistor (TFT) substrate, an opposing substrate and a liquid crystal (LC) layer disposed between the two substrates. The TFT substrate may include a plurality of gate lines, a plurality of data lines crossing the gate lines, a plurality of TFTs connected to the gate lines and the data lines, and a plurality of pixel electrodes connected to the TFTs. A TFT may include a gate electrode extended from a gate line, a source electrode extended to a data line, and a drain electrode spaced apart from the source electrode.

The LCD panel may not emit light by itself. In other words, it is not self-emissive. The LCD panel may receive light from the backside of the LCD panel or from the front of the LCD panel. The LCD panel may have limited side visibility.

Exemplary embodiments of the inventive concept provide a display apparatus with high side visibility and a method of driving the display apparatus. A multi-domain technique may be used.

According to an exemplary embodiment of the inventive concept, there is provided a display apparatus. The display apparatus includes a display panel comprising a data line, a gate line crossing the data line and a sub-pixel connected to the data line and the gate line, a gamma data generator comprising a spatial pattern having a high gamma and a low gamma corresponding to a plurality of sub-pixels arranged in an (n×m) matrix array in a space division method (where ‘n’ and ‘m’ are natural numbers), a temporal pattern having the high gamma and the low gamma corresponding to the plurality of sub-pixels in a time division method and a spatio-temporal pattern having the high gamma and the low gamma corresponding to the plurality of sub-pixels in both space division method and time division method, and to generate gamma data of a sub-pixel using the spatial pattern, the temporal pattern and the spatio-temporal pattern in a cascade method, and a data driver configured to convert the gamma data to a data voltage and to output the data voltage to the data line.

In an exemplary embodiment, at least one of the patterns further includes at least a third gamma corresponding to the plurality of sub-pixels.

In an exemplary embodiment, the gamma data generator may include a high gamma look-up table (LUT) configured to store high gamma data corresponding to grayscales based on the high gamma, a low gamma LUT configured to store low gamma data corresponding to the grayscales based on the low gamma, a first gamma controller configured to generate first gamma data of the sub-pixel being high gamma data or low gamma data corresponding to the image data of the sub-pixel based on a first preset pattern which is preset to one among the spatial, temporal and spatio-temporal patterns to the image data of the sub-pixel, and a second gamma controller configured to generate second gamma data of the sub-pixel being high gamma data or low gamma data corresponding to the first gamma data of the sub-pixel based on a second preset pattern which is preset to one among the spatial, temporal and spatio-temporal patterns.

In an exemplary embodiment, the gamma data generator may further include at least a third gamma controller configured to generate at least third gamma data for the sub-pixel corresponding to the first and second gamma data of the sub-pixel based on at least a third preset to one among a spatial, temporal or spatio-temporal pattern.

In an exemplary embodiment, the second gamma data of the sub-pixel may include first mixing gamma data, second mixing gamma data, third mixing gamma data and fourth mixing gamma data, the first mixing gamma data may be generated using the high gamma LUT of the first preset pattern and the high gamma LUT of the second preset pattern in the cascade method, the second mixing gamma data may be generated using the high gamma LUT of the first preset pattern and the low gamma LUT of the second preset pattern in the cascade method, the third mixing gamma data may be generated using the low gamma LUT of the first preset pattern and the high gamma LUT of the second preset pattern in the cascade method, and the fourth mixing gamma data may be generated using the low gamma LUT of the first preset pattern and the low gamma LUT of the second preset pattern in the cascade method.

In an exemplary embodiment, a number of mixing conditions of the first preset pattern and second preset pattern may be at least 9.

In an exemplary embodiment, the temporal pattern, the spatial pattern and the spatio-temporal pattern may respectively correspond to a plurality of sub-pixels arranged in a (2×2) matrix array.

In an exemplary embodiment, the display apparatus may further include a pattern detector configured to detect an image pattern of the image data, and to determine the first preset pattern and the second preset pattern corresponding to the image pattern.

In an exemplary embodiment, the sub-pixel may include a plurality of sub-areas and each of the plurality of sub-areas is individually driven.

According to an exemplary embodiment of the inventive concept, there is provided a method of driving a display apparatus which includes a data line, a gate line crossing the data line and a sub-pixel connected to the data line and the gate line. The method may include generating gamma data of a sub-pixel using a spatial pattern, a temporal pattern and a spatio-temporal pattern in a cascade method, the spatial pattern having a high gamma and a low gamma corresponding to a plurality of sub-pixels arranged in an (n×m) matrix array in a space division method (where ‘n’ and ‘m’ are natural numbers), the temporal pattern having the high gamma and the low gamma corresponding to the plurality of sub-pixels in a time division method and the spatio-temporal pattern having the high gamma and the low gamma corresponding to the plurality of sub-pixels in both space division method and time division method, and converting the gamma data to a data voltage to output the data voltage to the data line.

In an exemplary embodiment, at least one of the patterns may further include at least a third gamma corresponding to the plurality of sub-pixels.

In an exemplary embodiment, the method may further include generating first gamma data of the sub-pixel being high gamma data or low gamma data corresponding to the image data of the sub-pixel based on a first preset pattern which is preset to one among the spatial, temporal and spatio-temporal patterns, and generating second gamma data of the sub-pixel being high gamma data or low gamma data corresponding to the first gamma data of the sub-pixel based on a second preset pattern which is preset to one among the spatial, temporal and spatio-temporal patterns to the first gamma data of the sub-pixel.

In an exemplary embodiment, the method may further include generating third gamma data for the sub-pixel corresponding to the first and second gamma data of the sub-pixel based on a third preset pattern that is preset to one among spatial, temporal or spatio-temporal patterns.

In an exemplary embodiment, the method may further include generating gamma data of the sub-pixel using a high gamma look-up table (LUT) which is configured to store high gamma data corresponding to grayscales based on the high gamma and a low gamma LUT which is configured to store low gamma data corresponding to the grayscales based on the low gamma.

In an exemplary embodiment, the second gamma data of the sub-pixel may include first mixing gamma data, second mixing gamma data, third mixing gamma data and fourth mixing gamma data, the first mixing gamma data may be generated using the high gamma LUT of the first preset pattern and the high gamma LUT of the second preset pattern in the cascade method, the second mixing gamma data may be generated using the high gamma LUT of the first preset pattern and the low gamma LUT of the second preset pattern in the cascade method, the third mixing gamma data may be generated using the low gamma LUT of the first preset pattern and the high gamma LUT of the second preset pattern in the cascade method, and the fourth mixing gamma data may be generated using the low gamma LUT of the first preset pattern and the low gamma LUT of the second preset pattern in the cascade method.

In an exemplary embodiment, a number of mixing conditions of the first preset pattern and second preset pattern may be at least 9.

In an exemplary embodiment, the temporal pattern, the spatial pattern and the spatio-temporal pattern may respectively correspond to a plurality of sub-pixels arranged in a (2×2) matrix array.

In an exemplary embodiment, the method may further include detecting an image pattern of the image data, and determining the first preset pattern and the second preset pattern corresponding to the image pattern.

In an exemplary embodiment, the sub-pixel may include a plurality of sub-areas and each of the plurality of sub-areas is individually driven.

According to the inventive concept, multi gammas may be designed using both high and low gammas and thus, side visibility may be high.

The above and other features of the inventive concept will become more apparent by describing in detail exemplary embodiments thereof with reference to the accompanying drawings, in which:

FIG. 1 is a block diagram illustrating a display apparatus according to an exemplary embodiment;

FIG. 2 is a block diagram illustrating a gamma data generator of FIG. 1 ;

FIG. 3 is a graphical diagram illustrating high and low gammas of FIG. 2 ;

FIG. 4 is a hybrid diagram illustrating a pattern memory of FIG. 2 ;

FIG. 5 is a hybrid diagram illustrating first and second gamma controller according to an exemplary embodiment;

FIG. 6 is a flowchart diagram illustrating a method of driving a display apparatus according to an exemplary embodiment;

FIG. 7 is a tabular diagram illustrating high and low gamma look-up tables according to an exemplary embodiment;

FIG. 8 is a hybrid diagram illustrating first and second gamma controller according to an exemplary embodiment;

FIG. 9 is a hybrid diagram illustrating first and second gamma controller according to an exemplary embodiment;

FIG. 10 is a block diagram illustrating a gamma data generator according to an exemplary embodiment;

FIGS. 11A and 11B are hybrid diagrams illustrating a pattern detector of FIG. 10 ; and

FIG. 12 a flowchart diagram illustrating a method of driving a display apparatus according to an exemplary embodiment.

Hereinafter, the inventive concept will be explained in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating a display apparatus according to an exemplary embodiment.

Referring to FIG. 1 , the display apparatus may include a display panel 100 , a timing controller 200 , a gamma data generator 300 , a data driver 400 connected between the gamma data generator and the display panel and between the timing controller and the display panel, and a gate driver 500 connected between the timing controller and the display panel.

The display panel 100 may include a plurality of data lines DL connected to the data driver, a plurality of gate lines GL connected to the gate driver, and a plurality of pixel units PU each connected between one of the plurality of data lines and one of the plurality of gate lines. The data lines DL extend in a first direction D 1 and are arranged in a second direction D 2 crossing the first direction D 1 . The gate lines GL extend in the second direction D 2 and are arranged in the first direction D 1 . The pixel units PU are arranged as a matrix array which includes a plurality of pixel rows and a plurality of pixel columns. Each of the pixel units PU may include a plurality of sub-pixels SP. For example, the pixel unit PU includes a red sub-pixel r, a green sub-pixel g and a blue sub-pixel b.

The timing controller 200 generally controls an operation of the display apparatus. The timing controller 200 is configured to receive an original synch signal OS, and to generate a plurality of control signals for driving the display panel 100 based on the original synch signal OS. The control signals may include a data control signal DCS for controlling the data driver 400 and a gate control signal GCS for controlling the gate driver 500 .

The data control signal DCS may include a horizontal synch signal, a vertical synch signal, a data enable signal, a polarity control signal and the like. The gate control signal GCS may include a vertical start signal, a gate clock signal, an output enable signal and the like.

The gamma data generator 300 includes a spatial pattern, a temporal pattern and a spatio-temporal pattern corresponding to a plurality of sub-pixels arranged in an (n×m) matrix array and is configured to generate gamma data of a sub-pixel using the spatial pattern, the temporal pattern and the spatio-temporal pattern in a cascade method

The spatial pattern has a high gamma H and a low gamma L corresponding to the sub-pixels arranged as the (n×m) matrix array in a space division method. According to the spatial pattern, during a same frame, the high gamma H may be applied to a first sub-pixel among the sub-pixels arranged as the (n×m) matrix array and the low gamma L may be applied to a second sub-pixel among the sub-pixels arranged as the (n×m) matrix array

The temporal pattern has the high gamma H and the low gamma L corresponding to the sub-pixels arranged as the (n×m) matrix array in a time division method. According to the temporal pattern, when the high gamma H is applied to a sub-pixel among the sub-pixels arranged as the (n×m) matrix array during a first frame, the low gamma L may be applied to the sub-pixel during a second frame which is a next frame of the first frame.

The spatio-temporal pattern has the high gamma H and the low gamma L corresponding to the sub-pixels arranged as the (n×m) matrix array in both the space division method and the time division method. According to the spatio-temporal pattern, when the high gamma H is applied to a first sub-pixel among the sub-pixels arranged as the (n×m) matrix array and the low gamma L is applied to a second sub-pixel among the sub-pixels arranged as the (n×m) matrix array during a first frame, and the low gamma L may be applied to the first sub-pixel and the high gamma H is applied to the second sub-pixel during a second frame which is a next frame of the first frame.

The data driver 400 is configured to convert the gamma data DOUT received from the gamma data generator 300 into a data voltage for driving the sub-pixel of the display panel 100 and to output the data voltage to the data line DL.

The gate driver 500 is configured to generate a plurality of gate signals and to sequentially output the gate signals to the gate lines GL of the display panel 100 .

FIG. 2 is a block diagram illustrating a gamma data generator of FIG. 1 . FIG. 3 is a diagram illustrating high and low gammas of FIG. 2 .

Referring to FIGS. 1 and 2 , the gamma data generator 300 may include a high gamma look-up table (LUT) 311 , a low gamma LUT 312 , a first pattern memory 330 , a first gamma controller 350 connected to an image data input DIN and the first pattern memory and the LUTs, a second pattern memory 370 , and a second gamma controller 390 connected to the first gamma controller and the second pattern memory and the LUTs and providing image data output DOUT.

The high gamma LUT 311 is configured to store high gamma data corresponding to grayscales based on the high gamma H as shown in FIG. 3 .

The low gamma LUT is configured to store low gamma data corresponding to the grayscales based on the low gamma L as shown in FIG. 3 .

The first pattern memory 330 is configured to store a spatial pattern, a temporal pattern and a spatio-temporal pattern.

The first gamma controller 350 is configured to generate first gamma data of the sub-pixel being high gamma data or low gamma data corresponding to the image data of the sub-pixel based on a first preset pattern which is preset to one among the spatial, temporal and spatio-temporal patterns.

The second pattern memory 370 is configured to store a spatial pattern, a temporal pattern and a spatio-temporal pattern.

The second gamma controller 390 is configured to generate second gamma data of the sub-pixel being high gamma data or low gamma data corresponding to the first gamma data of the sub-pixel based on a second preset pattern which is preset to one among the spatial, temporal and spatio-temporal patterns to the first gamma data of the sub-pixel.

For example, if the first preset pattern has the high gamma H corresponding to a sub-pixel and the second preset pattern has the high gamma H corresponding to the sub-pixel, the first gamma controller 350 is configured to output high gamma data corresponding to image data of the sub-pixel as first gamma data of the sub-pixel using the high gamma LUT and then, the second gamma controller 390 is configured to output high gamma data corresponding to the first gamma data of the sub-pixel as second gamma data of the sub-pixel using the high gamma LUT. Thus, the gamma data generator 300 may output first mixing gamma data HH corresponding to the image data of the sub-pixel by a high/high mixing gamma which is mixed from the high gammas H and H of the first and second preset patterns in the cascade method.

If the first preset pattern has the high gamma H corresponding to a sub-pixel and the second preset pattern has the low gamma L corresponding to the sub-pixel, the first gamma controller 350 is configured to output high gamma data corresponding to image data of the sub-pixel as first gamma data of the sub-pixel using the high gamma LUT and then, the second gamma controller 390 is configured to output low gamma data corresponding to the first gamma data of the sub-pixel as second gamma data of the sub-pixel using the low gamma LUT. Thus, the gamma data generator 300 may output second mixing gamma data HL corresponding to the image data of the sub-pixel by a high/low mixing gamma which is mixed from the high gamma H of the first preset pattern and the low gamma L of the second preset pattern in the cascade method.

If the first preset pattern has the low gamma L corresponding to a sub-pixel and the second preset pattern has the high gamma H corresponding to the sub-pixel, the first gamma controller 350 is configured to output low gamma data corresponding to image data of the sub-pixel as first gamma data of the sub-pixel using the low gamma LUT and then, the second gamma controller 390 is configured to output high gamma data corresponding to the first gamma data of the sub-pixel as second gamma data of the sub-pixel using the high gamma LUT. Thus, the gamma data generator 300 may output third mixing gamma data LH corresponding to the image data of the sub-pixel by a low/high mixing gamma which is mixed from the low gamma L of the first preset pattern and the high gamma H of the second preset pattern in the cascade method.

If the first preset pattern has the low gamma L corresponding to a sub-pixel and the second preset pattern has the low gamma L corresponding to the sub-pixel, the first gamma controller 350 is configured to output low gamma data corresponding to image data of the sub-pixel as first gamma data of the sub-pixel using the low gamma LUT and then, the second gamma controller 390 is configured to output low gamma data corresponding to the first gamma data of the sub-pixel as second gamma data of the sub-pixel using the low gamma LUT. Thus, the gamma data generator 300 may output fourth mixing gamma data LL corresponding to the image data of the sub-pixel by a low/low mixing gamma which is mixed from the low gamma L of the first preset pattern and the low gamma L of the second preset pattern in the cascade method.

Therefore, the gamma data generator 300 is configured to output one of a plurality of mixing gamma data HH, HL, LH and LL corresponding to the image data of the sub-pixel.

FIG. 4 is a diagram illustrating a pattern memory of FIG. 2 .

Referring to FIGS. 2 and 4 , first or second pattern memory 330 or 370 may be configured to store a plurality of spatial patterns S_PAT, a plurality of temporal patterns T_PAT and a plurality of spatio-temporal patterns TS_PAT corresponding to a plurality of sub-pixels arranged in an (n×m) matrix array (where ‘n’ and ‘m’ are natural numbers).

For example, referring to sub-pixels SP 1 , SP 2 , SP 3 and SP 4 arranged in a (2×2) matrix array, a first sub-pixel SP 1 is adjacent to a second sub-pixel SP 2 in a horizontal direction, a third sub-pixel SP 3 is adjacent to the first sub-pixel SP 1 in a vertical direction, a the fourth sub-pixel SP 4 is adjacent to the third sub-pixel SP 2 in the horizontal direction.

For example, the spatial pattern S_PAT has the high gamma H corresponding to the first and fourth sub-pixels SP 1 and SP 4 and has the low gamma L corresponding to the second and third sub-pixels SP 2 and SP 3 . Thus, the high gamma H and the low gamma L of S_PAT are divided in a space corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 but are not divided in a time corresponding to sequential first to fourth frames 1 f , 2 f , 3 f and 4 f . Thus, during sequential first to fourth frames 1 f , 2 f , 3 f and 4 f , the high gamma H is applied to the first and fourth sub-pixels SP 1 and SP 4 and the low gamma L is applied to the second and third sub-pixels SP 2 and SP 3 .

For example, the temporal pattern T_PAT has the high gamma H corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 during a first frame if and has the low gamma L corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 during a second frame 2 f . Thus, the high gamma H and the low gamma L of T_PAT are not divided in the space corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 but are divided in the time corresponding to sequential first to fourth frames 1 f , 2 f , 3 f and 4 f . Therefore, during sequential first to fourth frames 1 f , 2 f , 3 f and 4 f , the high gamma H and the low gamma L are alternately applied to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 .

For example, the spatio-temporal pattern TS_PAT has the high gamma H corresponding to the first and fourth sub-pixels SP 1 and SP 4 , has the low gamma L corresponding to the second and third sub-pixels SP 2 and SP 3 . Thus, the high gamma H and the low gamma L of TS_PAT are divided in the space corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 . In addition, the spatio-temporal pattern TS_PAT has the high gamma H corresponding to the first and fourth sub-pixels SP 1 and SP 4 and the low gamma L corresponding to the second and third sub-pixels SP 2 and SP 3 during a first frame 1 f and has the low gamma L corresponding to the first and fourth sub-pixels SP 1 and SP 4 and the high gamma H corresponding to the second and third sub-pixels SP 2 and SP 3 during a second frame 2 f . Thus, the high gamma H and the low gamma L are divided in the time corresponding to sequential first to fourth frames 1 f , 2 f , 3 f and 4 f . Therefore, the high gamma H and the low gamma L are divided in the space corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 , and are divided in the time corresponding to sequential first to fourth frames 1 f , 2 f , 3 f and 4 f.

As described above, the spatial pattern S_PAT has the high gamma H and the low gamma L corresponding to a plurality of sub-pixels arranged in an (n×m) matrix array in a space division method (‘n’ and ‘m’ are natural numbers). The temporal pattern T_PAT has the high gamma H and the low gamma L corresponding to the plurality of sub-pixels in a time division method. The spatio-temporal pattern TS_PAT has the high gamma H and the low gamma L corresponding to the plurality of sub-pixels in both a space and time division method. The spatial pattern S_PAT, the temporal pattern T_PAT and the spatio-temporal pattern TS_PAT may be designed variously, without limitation.

According to the exemplary embodiment, the first or second pattern memory 330 or 350 may include at least one spatial pattern, at least one temporal pattern and at least one spatio-temporal pattern.

In addition, the first gamma controller 350 and the second gamma controller 390 may individually select according to various driving conditions, such as a pixel structure and an inversion driving mode, etc.

According to the various driving conditions, the first gamma controller 350 may select one among the spatial pattern, the temporal pattern and the spatio-temporal pattern and then the second gamma controller 390 may select one among the spatial pattern, the temporal pattern and the spatio-temporal pattern. Thus, at least 9 gamma mixing conditions may be designed by the first gamma controller 350 and the second gamma controller 390 .

FIG. 5 is a diagram illustrating first and second gamma controllers according to an exemplary embodiment.

Referring to FIG. 5 , a first preset pattern may be referred as to a first spatio-temporal pattern TS_PAT 1 , and a second preset pattern may be referred as to a second spatio-temporal pattern TS_PAT 2 . The first and second spatio-temporal patterns TS_PAT 1 and TS_PAT 2 may corresponding to sub-pixels SP 1 , SP 2 , SP 3 and SP 4 arranged in a (2×2) matrix array.

The first spatio-temporal pattern TS_PAT 1 has a high gamma H corresponding to the first and fourth sub-pixels SP 1 and SP 4 and a low gamma L corresponding to the second and third sub-pixels SP 2 and SP 3 during a first frame, and has the low gamma L corresponding to the first and fourth sub-pixels SP 1 and SP 4 and high gamma H corresponding to the second and third sub-pixels SP 2 and SP 3 during a second frame.

The second spatio-temporal pattern TS_PAT 2 has the high gamma H and the low gamma L opposite to those of the first spatio-temporal pattern TS_PAT 1 , corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 .

Referring to FIGS. 2 and 5 , during a first frame 1 f , the first gamma controller 350 is configured to output first gamma data of the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 based on the first spatio-temporal pattern TS_PAT 1 stored in the first pattern memory 330 . The first gamma controller 350 is configured to output high gamma data of a high gamma LUT 311 corresponding to image data of the first sub-pixel SP 1 as first gamma data of the first sub-pixel SP 1 , low gamma data of a low gamma LUT 312 corresponding to image data of the second sub-pixel SP 2 as first gamma data of the second sub-pixel SP 2 , low gamma data of the low gamma LUT 312 corresponding to image data of the third sub-pixel SP 3 as first gamma data of the third sub-pixel SP 3 and high gamma data of the high gamma LUT 311 corresponding to image data of the fourth sub-pixel SP 4 as first gamma data of the fourth sub-pixel SP 4 .

Then, the second gamma controller 390 is configured to output second gamma data of the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 based on the second spatio-temporal pattern TS_PAT 2 stored in the second pattern memory 370 . The second gamma controller 390 is configured to output low gamma data of the low gamma LUT 312 corresponding to the first gamma data of the first sub-pixel SP 1 as second gamma data of the first sub-pixel SP 1 , high gamma data of the high gamma LUT 311 corresponding to the first gamma data of the second sub-pixel SP 2 as second gamma data of the second sub-pixel SP 2 , high gamma data of the high gamma LUT 311 corresponding to the first gamma data of the third sub-pixel SP 3 , and low gamma data of the low gamma LUT 312 corresponding to the first gamma data of the fourth sub-pixel SP 4 as second gamma data of the fourth sub-pixel SP 4 .

Therefore, during the first frame 1 f , the gamma data generator 300 is configured to output second mixing gamma data HL corresponding to the image data DIN of the first sub-pixel SP 1 , third mixing gamma data LH corresponding to the image data DIN of the second sub-pixel SP 2 , third mixing gamma data LH corresponding to the image data DIN of the third sub-pixel SP 3 and second mixing gamma data HL corresponding to the image data DIN of the fourth sub-pixel SP 4 (DOUT).

During a second frame 2 f , the gamma data generator 300 is configured to output third mixing gamma data LH corresponding to the image data DIN of the first sub-pixel SP 1 , second mixing gamma data HL corresponding to the image data DIN of the second sub-pixel SP 2 , second mixing gamma data HL corresponding to the image data DIN of the third sub-pixel SP 3 and third mixing gamma data LH corresponding to the image data DIN of the fourth sub-pixel SP 4 (DOUT).

During a third frame 3 f , the gamma data generator 300 is configured to output second mixing gamma data HL corresponding to the image data DIN of the first sub-pixel SP 1 , third mixing gamma data LH corresponding to the image data DIN of the second sub-pixel SP 2 , third mixing gamma data LH corresponding to the image data DIN of the third sub-pixel SP 3 and second mixing gamma data HL corresponding to the image data DIN of the fourth sub-pixel SP 4 (DOUT).

During a fourth frame 4 f , the gamma data generator 300 is configured to output third mixing gamma data LH corresponding to the image data DIN of the first sub-pixel SP 1 , second mixing gamma data HL corresponding to the image data DIN of the second sub-pixel SP 2 , second mixing gamma data HL corresponding to the image data DIN of the third sub-pixel SP 3 and third mixing gamma data LH corresponding to the image data DIN of the fourth sub-pixel SP 4 (DOUT).

Therefore, the gamma data generator 300 is configured to output mixing gamma data HL, LH, HL and LH respectively corresponding to image data of the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 .

FIG. 6 is a flowchart illustrating a method of driving a display apparatus according to an exemplary embodiment. FIG. 7 is a diagram illustrating high and low gamma look-up tables according to an exemplary embodiment.

Referring to FIGS. 5, 6 and 7 , image data of the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 are referred to as a 170-grayscale 170 G.

The first gamma controller 250 is configured to receive the 170-grayscale 170 G of the image data DIN corresponding to the first, second, third and fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 (Step S 110 ).

The first gamma controller 350 is configured to output first gamma data of the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 based on the first spatio-temporal pattern TS_PAT 1 stored in the first pattern memory 330 as shown in FIG. 5 . The first gamma controller 350 is configured to output high gamma data of a high gamma LUT 311 corresponding to image data of the first sub-pixel SP 1 as first gamma data of the first sub-pixel SP 1 , low gamma data of a low gamma LUT 312 corresponding to image data of the second sub-pixel SP 2 as first gamma data of the second sub-pixel SP 2 , low gamma data of the low gamma LUT 312 corresponding to image data of the third sub-pixel SP 3 as first gamma data of the third sub-pixel SP 3 and high gamma data of the high gamma LUT 311 corresponding to image data of the fourth sub-pixel SP 4 as first gamma data of the fourth sub-pixel SP 4 (Step S 120 ).

For example, referring to FIGS. 5 and 7 , the first gamma controller 350 is configured to output a 230-grayscale 230 G being the high gamma data of the high gamma LUT 311 corresponding to the 170-grayscale 170 G of the first sub-pixel SP 1 as the first gamma data of the first sub-pixel SP 1 , a 10-grayscale 10 G being the low gamma data of the low gamma LUT 312 corresponding to the 170-grayscale 170 G of the second sub-pixel SP 2 as the first gamma data of the second sub-pixel SP 2 , the 10-grayscale 10 G being the low gamma data of the low gamma LUT 312 corresponding to the 170-grayscale 170 G of the third sub-pixel SP 3 as the first gamma data of the third sub-pixel SP 3 and the 230-grayscale 230 G being the high gamma data of the high gamma LUT 311 corresponding to the 170-grayscale 170 G of the fourth sub-pixel SP 4 as the first gamma data of the fourth sub-pixel SP 4 .

Then, the second gamma controller 390 is configured to output second gamma data of the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 based on the second spatio-temporal pattern TS_PAT 2 stored in the second pattern memory 370 as shown in FIG. 5 . The second gamma controller 390 is configured to output low gamma data of the low gamma LUT 312 corresponding to the first gamma data of the first sub-pixel SP 1 as second gamma data of the first sub-pixel SP 1 , high gamma data of the high gamma LUT 311 corresponding to the first gamma data of the second sub-pixel SP 2 as second gamma data of the second sub-pixel SP 2 , high gamma data of the high gamma LUT 311 corresponding to the first gamma data of the third sub-pixel SP 3 , and low gamma data of the low gamma LUT 312 corresponding to the first gamma data of the fourth sub-pixel SP 4 as second gamma data of the fourth sub-pixel SP 4 (Step S 130 ).

For example, referring to FIGS. 5 and 7 , the second gamma controller 390 is configured to output a 160-grayscale 160 G being low gamma data of the low gamma LUT 312 corresponding to the 230-grayscale 230 G being the first gamma data of the first and fourth sub-pixels SP 1 and SP 4 as second gamma data of the first and fourth sub-pixels SP 1 and SP 4 . Thus, the gamma data generator 300 is configured to output the 160-grayscale 160 G of second mixing gamma data HL corresponding to the 170-grayscale 170 G being the image data of the first and fourth sub-pixels SP 1 and SP 4 .

In addition, the second gamma controller 390 is configured to output a 80-grayscale 80 G being low gamma data of the low gamma LUT 312 corresponding to the 10-grayscale 10 G being the first gamma data of the second and third sub-pixels SP 2 and SP 3 as second gamma data of the second and third sub-pixels SP 2 and SP 3 . Thus, the gamma data generator 300 is configured to output the 80-grayscale 80 G of third mixing gamma data LH corresponding to the 170-grayscale 170 G being the image data of the second and third sub-pixels SP 2 and SP 3 .

Although not shown in the figures, when the high gamma H of the first spatio-temporal pattern and the high gamma H of the second spatio-temporal pattern are applied to a sub-pixel having the image data of the 170-grayscale 170 G, the gamma data generator 300 may be configured to output first mixing gamma data HH of a 255-grayscale 255 G corresponding to the 170-grayscale 170 G. When the low gamma L of the first spatio-temporal pattern and the low gamma L of the second spatio-temporal pattern are applied to a sub-pixel having the image data of the 170-grayscale 170 G, the gamma data generator 300 may be configured to output fourth mixing gamma data LL of a 0-grayscale OG corresponding to the 170-grayscale 170 G.

FIG. 8 is a diagram illustrating first and second gamma controllers according to an exemplary embodiment.

Referring to FIG. 8 , a first preset pattern may be referred to as a spatio-temporal pattern TS_PAT, and a second preset pattern may be referred to as a spatial pattern S_PAT. The first and second preset patterns may correspond to sub-pixels SP 1 , SP 2 , SP 3 and SP 4 arranged in a (2×2) matrix array.

The spatio-temporal pattern TS_PAT has a high gamma H corresponding to the first and fourth sub-pixels SP 1 and SP 4 and a low gamma L corresponding to the second and third sub-pixels SP 2 and SP 3 during a first frame, and has the low gamma L corresponding to the first and fourth sub-pixels SP 1 and SP 4 and high gamma H corresponding to the second and third sub-pixels SP 2 and SP 3 during a second frame.

The spatial pattern S_PAT has the high gamma H corresponding to the first and fourth sub-pixels SP 1 and SP 4 and the low gamma L corresponding to the second and third sub-pixels SP 2 and SP 3 .

Referring to FIGS. 2 and 8 , during a first frame 1 f , the first gamma controller 350 is configured to output high gamma data of a high gamma LUT 311 corresponding to image data of the first sub-pixel SP 1 as first gamma data of the first sub-pixel SP 1 , low gamma data of a low gamma LUT 312 corresponding to image data of the second sub-pixel SP 2 as first gamma data of the second sub-pixel SP 2 , low gamma data of the low gamma LUT 312 corresponding to image data of the third sub-pixel SP 3 as first gamma data of the third sub-pixel SP 3 and high gamma data of the high gamma LUT 311 corresponding to image data of the fourth sub-pixel SP 4 as first gamma data of the fourth sub-pixel SP 4 , based on the spatio-temporal pattern TS_PAT in the first pattern memory 330 .

Then, the second gamma controller 390 is configured to output high gamma data of the high gamma LUT 311 corresponding to the first gamma data of the first sub-pixel SP 1 as second gamma data of the first sub-pixel SP 1 , low gamma data of the low gamma LUT 312 corresponding to the first gamma data of the second sub-pixel SP 2 as second gamma data of the second sub-pixel SP 2 , low gamma data of the low gamma LUT 312 corresponding to the first gamma data of the third sub-pixel SP 3 , and high gamma data of the high gamma LUT 311 corresponding to the first gamma data of the fourth sub-pixel SP 4 as second gamma data of the fourth sub-pixel SP 4 , based on the spatial pattern S_PAT in the second pattern memory 370 .

Therefore, during the first frame 1 f , the gamma data generator 300 is configured to output first mixing gamma data HH corresponding to the image data DIN of the first sub-pixel SP 1 , fourth mixing gamma data LL corresponding to the image data DIN of the second sub-pixel SP 2 , fourth mixing gamma data LL corresponding to the image data DIN of the third sub-pixel SP 3 and first mixing gamma data HH corresponding to the image data DIN of the fourth sub-pixel SP 4 (DOUT).

During a second frame 2 f , the gamma data generator 300 is configured to output third mixing gamma data LH corresponding to the image data DIN of the first sub-pixel SP 1 , second mixing gamma data HL corresponding to the image data DIN of the second sub-pixel SP 2 , second mixing gamma data HL corresponding to the image data DIN of the third sub-pixel SP 3 and third mixing gamma data LH corresponding to the image data DIN of the fourth sub-pixel SP 4 (DOUT).

During a third frame 3 f , the gamma data generator 300 is configured to output first mixing gamma data HH corresponding to the image data DIN of the first sub-pixel SP 1 , fourth mixing gamma data LL corresponding to the image data DIN of the second sub-pixel SP 2 , fourth mixing gamma data LL corresponding to the image data DIN of the third sub-pixel SP 3 and first mixing gamma data HH corresponding to the image data DIN of the fourth sub-pixel SP 4 (DOUT).

During a fourth frame 4 f , the gamma data generator 300 is configured to output third mixing gamma data LH corresponding to the image data DIN of the first sub-pixel SP 1 , second mixing gamma data HL corresponding to the image data DIN of the second sub-pixel SP 2 , second mixing gamma data HL corresponding to the image data DIN of the third sub-pixel SP 3 and third mixing gamma data LH corresponding to the image data DIN of the fourth sub-pixel SP 4 (DOUT).

FIG. 9 is a diagram illustrating first and second gamma controllers according to an exemplary embodiment.

Referring to FIG. 9 , a first preset pattern may be referred as to a spatial pattern S_PAT, and a second preset pattern may be referred as to a temporal pattern T_PAT. The first and second preset patterns may correspond to sub-pixels SP 1 , SP 2 , SP 3 and SP 4 arranged in a (2×2) matrix array.

The spatial pattern S_PAT has a high gamma H corresponding to the first and fourth sub-pixels SP 1 and SP 4 and a low gamma L corresponding to the second and third sub-pixels SP 2 and SP 3 .

The temporal pattern T_PAT has the high gamma H corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 during a first frame 1 f , has the low gamma L corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 during a second frame 2 f , has the high gamma H corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 during a third frame 3 f and has the low gamma L to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 during a fourth frame 4 f.

Referring to FIGS. 2 and 9 , during the first frame 1 f , the first gamma controller 350 is configured to output high gamma data of a high gamma LUT 311 corresponding to image data of the first sub-pixel SP 1 as first gamma data of the first sub-pixel SP 1 , low gamma data of a low gamma LUT 312 corresponding to image data of the second sub-pixel SP 2 as first gamma data of the second sub-pixel SP 2 , low gamma data of the low gamma LUT 312 corresponding to image data of the third sub-pixel SP 3 as first gamma data of the third sub-pixel SP 3 and high gamma data of the high gamma LUT 311 corresponding to image data of the fourth sub-pixel SP 4 as first gamma data of the fourth sub-pixel SP 4 , based on the spatial pattern S_PAT in the first pattern memory 330 .

Then, the second gamma controller 390 is configured to output high gamma data of the high gamma LUT 311 corresponding to the first gamma data of the first sub-pixel SP 1 as second gamma data of the first sub-pixel SP 1 , high gamma data of the high gamma LUT 311 corresponding to the first gamma data of the second sub-pixel SP 2 as second gamma data of the second sub-pixel SP 2 , high gamma data of the high gamma LUT 311 corresponding to the first gamma data of the third sub-pixel SP 3 , and high gamma data of the high gamma LUT 311 corresponding to the first gamma data of the fourth sub-pixel SP 4 as second gamma data of the fourth sub-pixel SP 4 , based on the temporal pattern T_PAT in the second pattern memory 370 .

Therefore, during the first frame 1 f , the gamma data generator 300 is configured to output first mixing gamma data HH corresponding to the image data DIN of the first sub-pixel SP 1 , third mixing gamma data LH corresponding to the image data DIN of the second sub-pixel SP 2 , third mixing gamma data LH corresponding to the image data DIN of the third sub-pixel SP 3 and first mixing gamma data HH corresponding to the image data DIN of the fourth sub-pixel SP 4 (DOUT).

During a second frame 2 f , the gamma data generator 300 is configured to output second mixing gamma data HL corresponding to the image data DIN of the first sub-pixel SP 1 , fourth mixing gamma data LL corresponding to the image data DIN of the second sub-pixel SP 2 , fourth mixing gamma data LL corresponding to the image data DIN of the third sub-pixel SP 3 and second mixing gamma data HL corresponding to the image data DIN of the fourth sub-pixel SP 4 (DOUT).

During a third frame 3 f , the gamma data generator 300 is configured to output first mixing gamma data HH corresponding to the image data DIN of the first sub-pixel SP 1 , third mixing gamma data LH corresponding to the image data DIN of the second sub-pixel SP 2 , third mixing gamma data LH corresponding to the image data DIN of the third sub-pixel SP 3 and first mixing gamma data HH corresponding to the image data DIN of the fourth sub-pixel SP 4 (DOUT).

During a fourth frame 4 f , the gamma data generator 300 is configured to output second mixing gamma data HL corresponding to the image data DIN of the first sub-pixel SP 1 , fourth mixing gamma data LL corresponding to the image data DIN of the second sub-pixel SP 2 , fourth mixing gamma data LL corresponding to the image data DIN of the third sub-pixel SP 3 and second mixing gamma data HL corresponding to the image data DIN of the fourth sub-pixel SP 4 (DOUT).

FIG. 10 is a block diagram illustrating a gamma data generator according to an exemplary embodiment. FIGS. 11A and 11B are diagrams illustrating a pattern detector of FIG. 10 .

Referring to FIGS. 1 and 10 , the gamma data generator 300 A may include a high gamma LUT 311 , a low gamma LUT 312 , a pattern detector 320 connected to the data image data input, a first pattern memory 330 connected to the pattern detector, a first gamma controller 350 connected to an image data input DIN and the first pattern memory and the LUTs, a second pattern memory 370 connected to the pattern detector, and a second gamma controller 390 connected to the second pattern memory and the first gamma controller and the LUTs and providing image data output DOUT.

The high gamma LUT 311 is configured to store high gamma data corresponding to each of the grayscales based on the high gamma H as shown in FIG. 3 .

The low gamma LUT is configured to store low gamma data corresponding to each of the grayscales based on the low gamma L as shown in FIG. 3 .

The pattern detector 320 is configured to analyze the image data and to detect an image pattern of the image data. The pattern detector 320 is configured to determine an optimal first preset pattern and an optimal second preset pattern corresponding to the image pattern in order that display defects according to the image pattern may be substantially invisible to an observer.

The first pattern memory 330 is configured to store a spatial pattern, a temporal pattern and a spatio-temporal pattern.

The first gamma controller 350 is configured to select a first preset pattern which is one among the spatial, temporal and spatio-temporal patterns in the first pattern memory 330 based on a control of the pattern detector 320 , and to generate first gamma data of the sub-pixel being high gamma data or low gamma data corresponding to the image data of the sub-pixel using the first preset pattern.

The second pattern memory 370 is configured to store a spatial pattern, a temporal pattern and a spatio-temporal pattern.

The second gamma controller 390 is configured to select a second preset pattern which is one among the spatial, temporal and spatio-temporal patterns in the second pattern memory 370 based on a control of the pattern detector 320 , and to generate second gamma data of the sub-pixel being high gamma data or low gamma data corresponding to the first gamma data of the sub-pixel using the second preset pattern.

For example, as shown in FIG. 11A , when the image pattern is a dot pattern, red and green sub-pixels view brighter than a blue sub-pixel. Thus, when the image pattern is a dot pattern, a display defect in which the red and green sub-pixels view brighter than a blue sub-pixel may be invisible to an observer by a mixing condition which is mixed from the temporal pattern T_PAT and the spatial pattern S_PAT.

Therefore, when the image pattern is the dot pattern such as shown in FIG. 11A , the temporal pattern T_PAT may be selected as the optimal first preset pattern and the spatial pattern S_PAT may be selected as the optimal second preset pattern.

The first gamma controller 350 is configured to output the first gamma data corresponding to the image data using the temporal pattern T_PAT in the first pattern memory 330 based on the control of the pattern detector 320 . Then, the second gamma controller 390 is configured to output the second gamma data corresponding to the first gamma data using the spatial pattern S_PAT in the second pattern memory 370 based on the control of the pattern detector 320 .

As described above, according to the exemplary embodiment, an optimal mixing condition is determined according to the image pattern such that display quality as well as side visibility may be optimized.

FIG. 12 a flowchart illustrating a method of driving a display apparatus according to an exemplary embodiment.

Referring to FIGS. 10, 11A, 11B and 12 , the pattern detector 320 is configured to detect an image pattern of the image data (Step S 200 ). The pattern detector 320 is configured to determine optimal first and second preset patterns to avoid display defects corresponding to the image pattern (Step S 210 ).

For example, when the image pattern is the dot pattern as shown in FIG. 11A , the pattern detector 320 may determine the temporal pattern T_PAT as the first preset pattern the spatial pattern S_PAT as the second preset pattern.

Referring to FIG. 11B , the temporal pattern T_PAT and the spatial pattern S_PAT may correspond to sub-pixels SP 1 , SP 2 , SP 3 and SP 4 arranged in a (2×2) matrix array, without limitation. The temporal pattern T_PAT has a high gamma H corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 during a first frame 1 f , has a low gamma L corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 during a second frame 2 f , has the low gamma L corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 during a third frame 3 f and has the high gamma H corresponding to the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 during a fourth frame 4 f.

The spatial pattern S_PAT has the low gamma L corresponding to the first and fourth sub-pixels SP 1 and SP 4 and the high gamma H corresponding to the second and third sub-pixels SP 2 and SP 3 .

Referring to FIGS. 10 and 11B , during the first frame 1 f , the first gamma controller 350 is configured to output high gamma data of the high gamma LUT 311 corresponding to the image data of the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 as first gamma data of the first to fourth sub-pixels SP 1 , SP 2 , SP 3 and SP 4 , based on the temporal pattern T_PAT in the first pattern memory 330 (Step S 220 ).

Then, the second gamma controller 390 is configured to output low gamma data of the low gamma LUT 312 corresponding to the first gamma data of the first sub-pixel SP 1 as second gamma data of the first sub-pixel SP 1 , high gamma data of the high gamma LUT 311 corresponding to the first gamma data of the second sub-pixel SP 2 as second gamma data of the second sub-pixel SP 2 , high gamma data of the high gamma LUT 311 corresponding to the first gamma data of the third sub-pixel SP 3 , and low gamma data of the low gamma LUT 312 corresponding to the first gamma data of the fourth sub-pixel SP 4 as second gamma data of the fourth sub-pixel SP 4 , based on the spatial pattern S_PAT in the second pattern memory 370 (Step S 230 ).

Therefore, during the first frame 1 f , the gamma data generator 300 A is configured to output second mixing gamma data HL corresponding to the image data DIN of the first sub-pixel SP 1 , first mixing gamma data HH corresponding to the image data DIN of the second sub-pixel SP 2 , first mixing gamma data HH corresponding to the image data DIN of the third sub-pixel SP 3 and second mixing gamma data HL corresponding to the image data DIN of the fourth sub-pixel SP 4 .

During a second frame 2 f , the gamma data generator 300 is configured to output fourth mixing gamma data LL corresponding to the image data DIN of the first sub-pixel SP 1 , third mixing gamma data LH corresponding to the image data DIN of the second sub-pixel SP 2 , third mixing gamma data LH corresponding to the image data DIN of the third sub-pixel SP 3 and fourth mixing gamma data LL corresponding to the image data DIN of the fourth sub-pixel SP 4 .

During the third frame 3 f , the gamma data generator 300 is configured to output fourth mixing gamma data LL corresponding to the image data DIN of the first sub-pixel SP 1 , third mixing gamma data LH corresponding to the image data DIN of the second sub-pixel SP 2 , third mixing gamma data LH corresponding to the image data DIN of the third sub-pixel SP 3 and fourth mixing gamma data LL corresponding to the image data DIN of the fourth sub-pixel SP 4 .

During the fourth frame 4 f , the gamma data generator 300 A is configured to output second mixing gamma data HL corresponding to the image data DIN of the first sub-pixel SP 1 , first mixing gamma data HH corresponding to the image data DIN of the second sub-pixel SP 2 , first mixing gamma data HH corresponding to the image data DIN of the third sub-pixel SP 3 and second mixing gamma data HL corresponding to the image data DIN of the fourth sub-pixel SP 4 .

Although not shown in figures, each sub-pixel may be divided into a plurality of sub-areas, and each of the plurality of sub-areas may be individually driven. For example, the sub-pixel may be divided into a first sub-area and a second sub-area.

In this case, as the described exemplary embodiments above, each of the first and second sub-areas is driven using a mixing gamma which is mixed from the high gamma and the low gamma, such as a high/high mixing gamma, a high/low mixing gamma, a low/high mixing gamma and a low/low mixing gamma.

According to the exemplary embodiments, multi-gammas may be designed using both high and low gammas and thus, side visibility may be optimized. In alternate embodiments, the high gamma need not be universally as high as or higher than the low gamma. In alternate embodiments, more than two gamma look-up tables, curves or functions may be connected to the gamma controllers. In alternate embodiments, two or more of the same or different types among the spatial, temporal, or spatio-temporal methods may be used simultaneously. In alternate embodiments, more than two gamma controllers may be configured to generate additional gamma data for a plurality of sub-pixels.

The foregoing is illustrative of the inventive concept and is not to be construed as limiting thereof. Although a few exemplary embodiments of the inventive concept have been described, those of ordinary skill in the pertinent art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of the inventive concept. Accordingly, all such modifications are intended to be included within the scope of the inventive concept as defined in the claims. Therefore, it is to be understood that the foregoing is illustrative of the inventive concept and is not to be construed as limited to the specific exemplary embodiments disclosed, and that modifications to the disclosed exemplary embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims. The inventive concept is defined by the following claims, with equivalents of the claims to be included therein.