KR101419848B1 - Liquid crystal display and driving method of the same - Google Patents

Abstract

A liquid crystal display device capable of improving the display quality and a driving method of the liquid crystal display device are provided. A liquid crystal display device includes a graphic controller for providing a set of conversion data for correcting raw image data and raw image data, a timing controller for correcting the input original image data using the conversion data set and outputting the corrected image data, A data driver for receiving the corrected image data and selecting and providing the gradation voltage corresponding to the corrected image data, and a liquid crystal panel for displaying an image in accordance with the voltage level of the gradation voltage.

Liquid crystal display, dithering, noise

Description

[0001] The present invention relates to a liquid crystal display and a driving method thereof,

1 is a block diagram illustrating a liquid crystal display according to some embodiments of the present invention.

2 is a block diagram illustrating a graphics controller and a timing controller of a liquid crystal display according to an exemplary embodiment of the present invention.

3 is a signal diagram for explaining the transmission of the transform data set of Fig.

4 is a graph for explaining conversion data.

FIG. 5 is a diagram for explaining the dithering processing unit of FIG. 2. FIG.

6 is a block diagram illustrating a graphic controller and a timing controller of a liquid crystal display according to another embodiment of the present invention.

7 is a signal diagram for explaining the transmission of the transform data set.

8 is a block diagram illustrating a timing controller of a liquid crystal display according to another embodiment of the present invention.

9 is a graph for explaining the data conversion unit of FIG.

10 is a block diagram illustrating a liquid crystal display device according to another embodiment of the present invention.

11 is a signal diagram for explaining the transmission of the transform data set.

12 is a flowchart illustrating a method of driving a liquid crystal display according to an embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS (S)

10: liquid crystal display device 100: graphic controller

200: timing controller 210: gamma converter

220: dithering processing unit 230:

300: memory unit 304: frame memory

400: Data driver 500: Gate driver

600: liquid crystal panel 700: gradation voltage generator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a driving method thereof, and more particularly, to a liquid crystal display device and a driving method thereof that can improve display quality.

BACKGROUND ART [0002] Liquid crystal display devices have been developed in accordance with the demands for a large screen, a light weight, and a thin display in the field of a display device such as a television (hereinafter, referred to as 'TV') and have been put to practical use in TVs and PC monitors.

Particularly, in the case of a liquid crystal TV, in order to improve display quality, a graphics controller and a timing controller process image data inputted from the outside. This signal processing process includes a gamma correction process, in which a bit expansion is essential. The image data processed by the graphic controller is supplied to a timing controller, which is again subjected to signal processing in accordance with the characteristics of the liquid crystal panel in the timing controller. However, the bits of image data that can be processed by the timing controller and the data driver are limited. That is, when the graphics controller and the timing controller perform signal processing through bit expansion to improve the display quality, the graphics controller and the timing controller must respectively reduce the bits of the image data through the dithering process.

In this case, since the image data is dithered in the graphic controller and the timing controller is also required to perform the dithering process, noise is generated in this process and the display quality is degraded.

SUMMARY OF THE INVENTION The present invention provides a liquid crystal display device capable of improving display quality.

It is another object of the present invention to provide a method of driving a liquid crystal display device capable of improving display quality.

The technical objects of the present invention are not limited to the above-mentioned technical problems, and other technical subjects not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a liquid crystal display comprising: a graphics controller for providing raw image data and a set of transform data for correcting the raw image data; A data driver for receiving the corrected image data and selecting and providing a gradation voltage corresponding to the corrected image data, and a data driver for receiving the corrected image data, And a liquid crystal panel for displaying an image.

According to another aspect of the present invention, there is provided a liquid crystal display comprising a graphics controller for providing a first set of transformed data and a second set of transformed data for correcting raw image data and the raw image data, The original image data input using the first conversion data set is corrected and converted into first correction image data, and the first correction image data, the first correction image data of the previous frame, and the second conversion data set are used A data driver for receiving the second corrected image data and selecting and outputting a gradation voltage corresponding to the second corrected image data; and a data driver for receiving the first corrected image data and the second corrected image data, And a liquid crystal panel for displaying an image in accordance with the voltage level of the gradation voltage.

According to another aspect of the present invention, there is provided a method of driving a liquid crystal display device, the method comprising: providing a set of transformed data for correcting raw image data and raw image data; And outputting corrected image data; selecting and supplying a gradation voltage corresponding to the corrected image data; and displaying an image in accordance with the voltage level of the gradation voltage .

Other details of the present invention are included in the detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, the conversion data set provided in the graphic controller will be described as an example in which the original image data is provided in a frame blank period different from the period in which the original image data is provided, To distinguish the image data from that provided, the signal leader indicating the provision of the transform data set in the figures is indicated by the dotted line.

1 is a block diagram illustrating a liquid crystal display according to some embodiments of the present invention.

1, a liquid crystal display 10 includes a graphic controller 100, a timing controller 200, a memory unit 300, a data driver 400, a gate driver 500, a liquid crystal panel 600, And a gradation voltage generator 700. Such a liquid crystal display device 10 may be, for example, a liquid crystal TV.

The graphic controller 100 provides a conversion data set (LUT), raw image data (DAT), and various clock signals (DE, Hsync, Vsync, Mclk).

The conversion data set (LUT) includes a plurality of conversion data (DAT_ACC, DAT_DCC) corresponding one-to-one with a plurality of original image data (DAT). Here, the raw image data DAT may be m bits as the data for R, G and B, and the converted data DAT_ACC and DAT_DCC may be n bits (n? M). The conversion data DAT_ACC and DAT_DCC may be data for performing adaptive color correction (ACC) on the gamma characteristic of the raw image data DAT as an example of the gamma correction, or may be a dynamic capacitance compensation , DCC). The graphic controller 100 does not perform data conversion for improving the gamma characteristic and the response speed with respect to the raw image data DAT and outputs the converted data set LUT for changing the gamma characteristic or the response speed to the timing controller 200). The graphics controller 100 may provide such a transform data set (LUT) to the timing controller 200 during a section that does not provide a frame blank period, i.e., raw image data (DAT).

Meanwhile, the various clock signals DE, Hsync, Vsync, and Mclk are maintained at a high level during a period during which the raw image data DAT is output, for example, so that the signals provided from the graphic controller 100 to the timing controller 200 A data enable signal DE indicating that the data is the image data DAT, a vertical synchronizing signal Vsync notifying the start of one frame, a horizontal synchronizing signal Hsync discriminating the gate line, a main clock Mclk, and the like.

The timing controller 200 corrects the raw image data DAT by using the converted data set (LUT) and outputs the corrected image data DAT '.

More specifically, the timing controller 200 stores the conversion data set (LUT) provided in the frame blank interval in the memory unit 300. [ Next, when m-bit raw image data DAT is input, n-bit converted data DAT_ACC corresponding to the input raw image data DAT in the converted data set LUT stored in the memory unit 300, DAT_DCC) and corrects the raw image data DAT by using the converted data DAT_ACC and DAT_DCC. And then outputs the m-bit corrected image data DAT 'to the data driver 400. [ Particularly, when the timing controller 200 converts the gamma characteristic of the m-bit raw image data DAT, n-bit converted data DAT_ACC, DAT_DCC larger than m can be used. That is, gamma can be corrected through bit expansion, bit reduction can be performed again through dithering processing, and n-bit corrected image data DAT 'can be output.

The timing controller 200 also provides the gate control signal CONT1 and the data control signal CONT2 to the gate driver 500 and the data driver 400, respectively.

Here, the gate control signal CONT1 is a signal for controlling the operation of the gate driver 500, and includes a vertical start signal for starting the operation of the gate driver 500, a gate clock signal for determining the output timing of the gate- An output enable signal for determining the pulse width of the gate-on voltage, and the like.

The data control signal CONT2 is a signal for controlling the operation of the data driver 400 and includes a horizontal start signal for starting the operation of the data driver 400 and an output instruction signal for instructing the output of the data voltage.

The data driver 400 receives the data control signal CONT2 and the corrected image data DAT 'from the timing controller 200 and selects a gray scale voltage corresponding to the corrected image data DAT' .

The gate driver 500 is provided from the timing controller 200 in response to the gate control signal (CONT1) an input supplied from an external gate on / off voltage (Von, Voff), a plurality of gate lines (G ₁ -G _n) .

The liquid crystal panel 600 includes a plurality of gate lines G ₁ -G _n , a plurality of data lines D ₁ -D _m , gate lines G ₁ -G _n and data lines D ₁ -D _m , And a pixel PX formed in the intersecting region.

The gate lines G ₁ -G _n extend substantially in the row direction and are substantially parallel to each other, and the data lines D ₁ -D _m extend substantially in the column direction and are substantially parallel to each other. A plurality of gate lines (G ₁ -G _n), the gate on / off voltage (Von, Voff) outputted from the gate driver 500 is applied, the data driver (400 a plurality of data lines (D ₁ -D _m) Is applied to the data line. Therefore, when a data voltage is applied to each pixel, light corresponding to the difference between the data voltage and the common voltage Vcom is transmitted and a predetermined image is displayed.

The gradation voltage generator 700 includes a plurality of resistors connected in series between a node to which a driving voltage AVDD is applied and a ground to divide the voltage level of the driving voltage AVDD to generate a plurality of gradation voltages But did not show it. The internal circuit of the gradation voltage generating unit 700 is not limited to this, and may be variously implemented.

Such a liquid crystal display device 10 can improve display quality. For example, when the timing controller 200 performs gamma correction through bit expansion and performs dithering processing to provide the corrected image data DAT 'to the data driver 400, the corrected image data DAT' Since a single dithering process is performed, it is possible to prevent noise from being generated by a plurality of dithering processes.

Hereinafter, a liquid crystal display according to some embodiments of the present invention will be described with reference to FIGS. 2 to 9. FIG.

First, a liquid crystal display according to an embodiment of the present invention will be described with reference to FIGS. 2 to 5. FIG. FIG. 2 is a block diagram for explaining a graphic controller and a timing controller of a liquid crystal display according to an embodiment of the present invention, FIG. 3 is a signal diagram for explaining transmission of a transform data set of FIG. 2, FIG. 5 is a diagram for explaining the dithering processing unit of FIG. 2. FIG. 2, the DE signal, the horizontal synchronization signal Hsync, the vertical synchronization signal Vsync, and the main clock Mclk are omitted for convenience of explanation. 2, the original image data is m bits and the conversion data is n bits (n m). Hereinafter, the case where the raw image data is 8 bits and the conversion data is 10 bits is described as an example do. However, the present invention is not limited thereto.

2, the timing controller 201 receives a conversion data set (LUT_ACC) for converting the gamma characteristic of raw image data (DAT) from the graphic controller 101, stores the converted data set in the memory unit 301, Receives the raw image data DAT, and outputs the corrected image data DAT 'in which the gamma characteristic is converted.

Specifically, first, the timing controller 201 includes a gamma conversion unit 210 and a dithering processing unit 220.

The gamma conversion unit 210 stores the conversion data set LUT_ACC provided from the graphic controller 101 in the memory unit 301. [

3, the transfer of the conversion data set LUT_ACC from the graphic controller 101 will be described. The conversion data set LUT_ACC is output from the graphic controller 101 during the frame blank (FRAME BLANK) period.

More specifically, the graphic controller 101 transmits a masking bit (Masking) after the start of the frame blank (FRAME BLANK) period. For example, a plurality of bits are masked to zero to inform the timing controller 201 of the output of the conversion data set LUT_ACC. Next, the flag FLAG is transmitted. Here, the flag FLAG indicates the characteristic of the converted data set LUT_ACC. For example, the flag FLAG may indicate the type, length, and the like of the conversion data set LUT_ACC. Next, the conversion data set LUT_ACC is transmitted. The conversion data set LUT_ACC includes a plurality of conversion data DAT_ACC. One raw image data DAT and the converted data DAT_ACC correspond one-to-one and the original image data DAT has eight bits, so that the converted data set LUT_ACC may include 256 converted data DAT_ACC .

Here, since the timing controller 201 can receive 8-bit data per one main clock Mclk, one 10-bit converted data DAT_ACC can be input during the two main clocks Mclk. That is, the gamma conversion unit 210 can receive the converted data set LUT_ACC including 256 converted data DAT_ACC through 512 main clocks Mclk. The conversion data set LUT_ACC is stored in the memory unit 301 and can be stored in the memory unit 301 in units of 10-bit conversion data DAT_ACC. The converted data DAT_ACC, which is one-to-one correspondence with the raw image data DAT and which converts the gamma characteristics of the raw image data DAT, will be described later with reference to Fig.

Next, the graphic controller 101 provides the raw image data DAT to the timing controller 201 during a period in which the data enable signal DE is at a high level.

The gamma conversion unit 210 reads 10-bit converted data DAT_ACC corresponding to the supplied raw image data DAT from the memory unit 301 and supplies the converted data DAT_ACC to the dithering processing unit 220 to provide. Here, the raw image data DAT may be an address signal for reading 10-bit converted data DAT_ACC from the memory unit 301. [

The dithering processing unit 220 receives the 10-bit converted data DAT_ACC and provides 8-bit corrected image data DAT 'to the data driver 400 so that the data driver 400 can process the data. The operation of the dithering processing unit 220 will be described later with reference to FIG.

4 is a graph for explaining conversion data DAT_ACC that is one-to-one corresponded to the raw image data DAT and which converts the gamma characteristic of the raw image data DAT. Referring to Figs. 2 and 4, a target gamma curve TG and a raw gamma curve G1 are shown in a coordinate plane consisting of gray and transmittance. The original gamma curve G1 is a curve having a transmittance corresponding to the gray of the raw image data DAT and the target gamma curve TG corresponds to the gray of the raw image data DAT and the transmittance of the original gamma curve G1 And a different transmittance.

When the gray of the provided raw image data DAT is 128 and there is a specific transmittance T on the target gamma curve TG corresponding to 128 gray, the gray of the converted data DAT_ACC is the gray on the original gamma curve G1 And a gray value of 129.4 corresponding to the transmittance (T). That is, when the 128 gray original image data DAT is corrected by the conversion data DAT_ACC of 129.4 gray, the gamma characteristic is changed from the raw gamma curve G1 to the target gamma curve TG. That is, the conversion data DAT_ACC is data in which a plurality of original image data DAT are one-to-one correspondence with a plurality of conversion data DAT_ACC, and is data having a gamma characteristic different from that of the original image data DAT.

2 is supplied from the graphic controller 101 to the memory unit 301. When the conversion data set LUT_ACC including the plurality of conversion data DAT_ACC is supplied from the graphic controller 101, And when the raw image data DAT is inputted, the conversion data DAT_ACC corresponding thereto can be output to convert the gamma characteristic.

Here, in order to increase the precision of the gamma conversion, the gray of the decimal point is gray through the bit extension. For example, the raw image data DAT is 8 bits, 128 gray, and therefore 10,00000000, and the converted data DAT_ACC is 129.4 gray. If expressed in 10 bits, it can be 1000000101. In other words, two bits can be added to represent gray below the decimal point. Here, the case where the 8-bit raw image data DAT is expanded by 10-bit converted data DAT_ACC is described as an example, and the bits of the converted data DAT_ACC are the same as the bits of the raw image data DAT Or may be extended to 10 or more bits.

Referring to FIG. 5, a dithering processing unit 220 for converting 10-bit converted data DAT_ACC into 8-bit corrected image data DAT 'will be described.

The 10-bit converted data DAT_ACC can be divided into upper 8-bit data and lower 2-bit data, and the lower 2-bit data is '00', '01', '10', or '11'. In this case, in order to indicate that the data of the lower 2 bits is '00', all four adjacent pixels may be represented by data of the upper 8 bits. In order to indicate that the data of the lower 2 bits is '01', if a value obtained by adding 1 to the data of the upper 8 bits is displayed in one of the four neighboring pixels, the lower two bits Is " 01 ". At this time, the position of the pixel corresponding to the upper 8 bits + 1 may be shifted according to the frame as shown in FIG. 5 so that such flicker does not occur.

Similarly, when the lower two bits are '10', two pixels in the adjacent four pixels are represented by data of upper 8 bits + 1, and when the lower two bits are '11', three pixels are represented by upper 8 bits It is sufficient to display it as data of +1. Also in this case, the position of the pixel represented by 8-bit + 1 data may be changed in accordance with the frame so that flicker does not occur. For example, in FIG. 5, the positions of pixels are changed according to four frames of 4n, 4n + 1, 4n + 2 and 4n + 3.

A liquid crystal display according to another embodiment of the present invention will be described with reference to FIGS. 6 and 7. FIG. FIG. 6 is a block diagram for explaining a graphic controller and a timing controller of a liquid crystal display according to another embodiment of the present invention, and FIG. 7 is a signal diagram for explaining transmission of a transform data set. The same reference numerals are used for the components having the same functions as those shown in FIGS. 2 and 3, and a detailed description of the components will be omitted for the sake of convenience.

Referring to FIGS. 6 and 7, a graphic controller (not shown) converts an R conversion data set LUT_ACC_R, a G conversion data set LUT_ACC_G, and B (DAT_RC) And provides the transform data set LUT_ACC_B to the frame blank (FRAME BLANK) period, respectively. Here, the R conversion data set LUT_ACC_R, the G conversion data set LUT_ACC_G, and the B conversion data set LUT_ACC_B include a plurality of R-converted data DAT_ACC_R corresponding to a plurality of R, G, and B raw image data one- G conversion data DAT_ACC_G, and B conversion data DAT_ACC_B.

The timing controller 202 includes an R gamma conversion unit 211, a G gamma conversion unit 212 and a B gamma conversion unit 213. The R, G, and B gamma conversion units 211, 212, R conversion data set LUT_ACC_R, a G conversion data set LUT_ACC_G, and a B conversion data set LUT_ACC_B, and stores them in the memory unit 302. [ Since the flags FLAG_R, FLAG_G and FLAG_B indicate that the sequentially converted data sets LUT_ACC_R, LUT_ACC_G and LUT_ACC_B are the conversion data sets for R, G and B, the R-gamma conversion section 211, G gamma conversion section 212 and B gamma conversion section 213 convert the R conversion data set (LUT_ACC_R), G conversion data set (LUT_ACC_G) and B conversion data set (LUT_ACC_R) LUT_ACC_B) according to the flag FLAG_R, FLAG_G, FLAG_B.

Next, when the R, G, and B raw image data DAT_R, DAT_B, and DAT_B are input, the R gamma conversion unit 211, the G gamma conversion unit 212 and the B gamma conversion unit 213 respectively generate a raw image (DAT_ACC_R), G conversion data (DAT_ACC_G), and B conversion data DAT_ACC_B corresponding to the data, and provides it to the dithering processing unit (220).

The dithering processing unit 220 dithers the supplied 10-bit R-converted data DAT_ACC_R, G converted data DAT_ACC_G, and B-converted data DAT_ACC_B to generate 8-bit R-corrected image data DAT'_R, (DAT'G), and B corrected image data DAT'_B.

Such a liquid crystal display device performs gamma conversion for each of the R, G, and B image data DAT_R, DAT_B, and DAT_B, thereby improving display quality.

A liquid crystal display according to another embodiment of the present invention will be described with reference to FIGS. 8 and 9. FIG. FIG. 8 is a block diagram for explaining a timing controller of a liquid crystal display according to another embodiment of the present invention, and FIG. 9 is a graph for explaining the data converter of FIG. In FIG. 8, the raw image data is m bits and the converted data is shown as n bits (n? M). Hereinafter, the case where both the raw image data and the converted data are 8 bits will be described as an example. However, the present invention is not limited thereto.

8, the timing controller 203 receives the converted data set LUT_DCC and stores the converted data set LUT_DCC in the memory unit 303 and stores the raw image data DATn, the raw image data DATn-1 of the previous frame, A data conversion unit 230 for outputting the corrected image data DAT'n using the data DAT_DCC, and a frame memory 304. [

Specifically, the graphic controller first provides a conversion data set (LUT_DCC) for improving the response speed of the liquid crystal in the frame blank interval.

The data conversion unit 230 stores the converted data set LUT_DCC in the memory unit 303 and receives the raw image data DATn and the raw image data DATn-1 of the previous frame. The frame memory 304 stores the raw image data DATn-1 of the previous frame for one frame and provides the same to the data conversion unit 230. [

The data conversion unit 230 reads the conversion data DAT_DCC corresponding to the pair of the raw image data DATn-1 and the raw image data DATn of the previous frame from the memory unit 303, And corrects the data DATn to output corrected image data DAT'n.

The conversion data DAT_DCC is set such that when the difference between the gray of the raw image data DATn and the gray of the raw image data DATn-1 of the previous frame is equal to or larger than a predetermined reference value, May correspond to pairs of raw image data DATn-1.

8 and 9, the x-axis represents a frame, the y-axis represents gray, and the first graph G1 represents the gray level of the previous frame (n-1) input to the data conversion unit 230 And the second graph G2 represents the gray of the corrected image data DAT'n output from the data conversion unit 230. The gray scale of the original image data DATn-

 When the difference between the gray of the raw image data DATn-1 of the previous frame (n-1) and the gray of the raw image data DATn is equal to or larger than the predetermined reference value S, (Gray2-Gray1 > S) larger than the gray of the raw image data DATn-1 of the frame (n-1) than the reference value S, the data conversion section 230 corrects the raw image data DATn, And outputs the corrected image data DAT'n of the third gray (Gray3) larger than the gray of the raw image data DATn.

Here, the corrected image data DAT'n may be the same as the converted data DAT_DCC. That is, the data converter 230 corresponds to the pair of the raw image data DATn-1 of the previous frame n-1 of the first gray Gray1 and the raw image data DATn of the second gray Gray2 (DAT_DCC) of the third gray (Gray3) from the memory unit 303 and outputs it as the corrected image data DAT'n. Therefore, the conversion data set LUT_DCC is a pair of the conversion data set LUT_DCC when the difference between the gray of the original image data DATn-1 of the previous frame (n-1) and the gray of the original image data DATn is equal to or larger than the predetermined reference value S (DAT_DCC) corresponding only to the input data DAT_DCC. However, the correspondence relationship between the pair of the raw image data DATn-1 and the raw image data DATn of the previous frame (n-1) and the conversion data DAT_DCC is not limited thereto.

Through this process, when the corrected image data DAT'n of the third gray (Gray3) higher than the gray of the raw image data DATn is applied to the liquid crystal panel (see 600 in FIG. 1), a high voltage is applied to the liquid crystal And the liquid crystal is rapidly tilted. That is, it is possible to improve the display quality of the liquid crystal display device (see 10 in Fig. 1) by increasing the response speed of the liquid crystal. However, FIG. 9 is an example of data conversion for improving the response speed, and the present invention is not limited to this.

Hereinafter, a liquid crystal display device according to another embodiment of the present invention will be described with reference to FIGS. 10 and 11. FIG. FIG. 10 is a block diagram for explaining a liquid crystal display according to another embodiment of the present invention, and FIG. 11 is a signal diagram for explaining transmission of a transform data set. Components having the same functions as those shown in FIGS. 2, 3 and 8 are denoted by the same reference numerals, and a detailed description thereof will be omitted for the sake of convenience. In Fig. 10, the raw image data is m bits, the first conversion data is n bits (n > = m), and the second conversion data is k bits, which means that the bits of each data may be different Hereinafter, the case where the raw image data is 8 bits, the first conversion data is 10 bits, and the second conversion data is 8 bits will be described as an example. However, the present invention is not limited thereto.

10 and 11, a graphics controller (not shown) provides a first transform data set LUT_ACC and a second transform data set LUT_DCC in a frame blank period, Stores the first conversion data set LUT_ACC and the second conversion data set LUT_DCC in the first memory unit 301 and the second memory unit 303 respectively and receives the original image data DATn, And outputs data DAT'n-1.

Specifically, first, a graphic controller (not shown) provides a first conversion data set LUT_ACC for gamma correction and a second conversion data set LUT_DCC for improving the response speed of the liquid crystal.

More specifically, the transmission of the first conversion data set LUT_ACC and the second conversion data set LUT_DCC will be described in more detail with reference to FIG. 11. The graphic controller (not shown) first provides a masking bit 1 flag FLAG_A to inform first that a first transform data set LUT_ACC for gamma transform is provided. Then, after providing the first conversion data set LUT_ACC, the second flag FLAG_D is provided to inform that the first conversion data set LUT_ACC for improving the response speed is provided, and the second conversion data set LUT_DCC ).

The timing controller 204 includes a gamma conversion unit 210, a first memory unit 301, a dithering processing unit 220, a frame memory 304, a data conversion unit 230, and a second memory unit 303 .

The gamma conversion unit 210 and the data conversion unit 230 may output the first frame FLAG_A and the second frame FLAG_D among the signals provided by the graphics controller (not shown) in the frame blank interval (FRAME BLANK) , The first conversion data set (LUT_ACC), or the second conversion data set (LUT_DCC). The gamma conversion unit 210 and the data conversion unit 230 convert the first conversion data set LUT_ACC and the second conversion data set LUT_DCC into the first memory unit 301 and the second memory unit 302, .

When 8-bit raw image data DATn is applied, first, the gamma conversion unit 210 reads 10-bit first converted data DATn_ACC corresponding to the raw image data DATn from the first memory unit 301 And provides it to the dithering processing unit 220.

The dithering processing unit 220 converts the 10-bit first converted data DATn_ACC into 8-bit first corrected image data DAT'n_ACC and provides the 8-bit first corrected image data DAT'n_ACC to the frame memory 304 and the data converting unit 230.

The frame memory 304 delays the first corrected image data DAT'n_ACC by one frame and provides the data to the data conversion unit 230. [

The data converter 230 receives the first corrected image data DAT'n_ACC and the first corrected image data DAT'n_ 1_ACC of the previous frame and outputs the first corrected image data DAT'n_ACC and the previous corrected frame data DAT'n_ACC, From the second memory unit 303, second conversion data DAT_DCC corresponding to the pair of the first corrected image data DAT'n-1_ACC. And corrects the first corrected image data DAT'n_ACC using the read second converted data DAT_DCC to output the second corrected image data DAT'n.

Such a liquid crystal display device can correct the raw image data DATn in the timing controller 204 by using the conversion data set (LUT_ACC, LUT_DCC) provided from the graphic controller (not shown), so that the display quality can be improved. In other words, since the dithering process is performed once, the occurrence of noise due to dithering can be reduced. In addition, since the conversion data sets LUT_ACC and LUT_DCC are provided in the frame blank period, the conversion data sets LUT_ACC and LUT_DCC can be updated for each frame to realize the optimum image quality.

A driving method of a liquid crystal display according to an embodiment of the present invention will be described with reference to FIG. 12 is a flowchart illustrating a method of driving a liquid crystal display according to an embodiment of the present invention.

Referring to FIG. 12, first, raw image data and a transform data set are provided (S131).

Where the transform data set may be for transforming the gamma characteristic of the raw image data or may be for improving the response speed of the liquid crystal and may include a first transform data set and a second transform data set for both of them You may. The transform data set may be provided in a frame blank interval in which raw image data is not provided. More specifically, after the start of the frame blank interval, bit masking is performed to zero, a flag indicating the characteristics of the transform data set is provided, and conversion data can be provided.

Next, using the conversion data set, the provided original image data is corrected and corrected image data is output (S132).

The conversion data set may include n-bit (n? M) corrected image data corresponding to m-bit raw image data, and outputs m-bit corrected image data using the corrected image data.

Next, the gradation voltage corresponding to the corrected image data is selected and provided to the liquid crystal panel 600 (S133).

Then, an image is displayed in accordance with the voltage level of the provided gradation voltage (S134).

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

According to the liquid crystal display device and the driving method thereof of the present invention as described above, the following effects can be obtained.

First, it is possible to prevent the occurrence of noise due to a plurality of dithering processes and to improve display quality.

Second, it is possible to update the conversion data set for each frame to provide an optimal image.

Claims (22)

A graphics controller for providing raw image data and a set of transform data for correcting the raw image data; A timing controller that corrects the raw image data input using the conversion data set and outputs corrected image data; A data driver receiving the corrected image data and selecting and providing a gradation voltage corresponding to the corrected image data; And And a liquid crystal panel for displaying an image according to a voltage level of the gradation voltage, Wherein the graphics controller provides the transform data set in a frame blank period in which the raw image data is not provided. The method according to claim 1, Wherein the conversion data set includes a plurality of conversion data corresponding one-to-one with a plurality of the original image data, wherein the original image data is m bits and the conversion data is n bits (n? M). delete 3. The method of claim 2, The original gamma curve is a curve having a transmittance corresponding to the gray of the raw image data and the target gamma curve is a curve having a transmittance different from the transmittance of the original gamma curve corresponding to the gray of the raw image data, Wherein the gray of the transformed data is gray corresponding to the specific transmittance on the raw gamma curve when there is a specific transmittance on the target gamma curve corresponding to the gray of the original gamma curve, The timing controller includes: A gamma conversion unit that receives the raw image data and outputs the n-bit converted data corresponding to the raw image data from the converted data set; And a dithering processor receiving the n-bit converted data and outputting the m-bit corrected image data. delete The method according to claim 1, Wherein the transform data set includes an R transform data set, a G transform data set, and a B transform data set corresponding to each of the raw image data of R, G, and B, and the R, G, G and B conversion data corresponding one-to-one to the R, G, and B raw image data, wherein each of the R, G, and B raw image data is m bits and each of the R, G, The converted data is n bits (n? M) The timing controller includes: An R-gamma conversion unit that receives the R raw image data and outputs the n-bit R-converted data corresponding to the R raw image data from the R-converted data, A G gamma conversion unit that receives the G raw image data and outputs the n bits of G conversion data corresponding to the G raw image data in the G conversion data set; A B gamma conversion unit that receives the B raw image data and outputs the n bits of B conversion data corresponding to the B raw image data in the B conversion data set; And a dithering processing unit which receives the n bits of R change data, G conversion data, and B conversion data and outputs m bit R corrected image data, G corrected image data, and B corrected image data. delete The method according to claim 1, Wherein the conversion data set includes conversion data corresponding to a pair of the raw image data and the raw image data of a previous frame, Wherein the timing controller corrects the raw image data using the converted data and outputs the corrected image data when the difference between the gray of the raw image data and the gray of the raw image data of the previous frame is equal to or greater than a reference value, . delete The method according to claim 1, Wherein the graphics controller sequentially provides a masking bit, a flag indicating a characteristic of the transform data set, and the transform data set after the start of the frame blank interval. delete A graphics controller for providing a first set of transformed data and a second set of transformed data for correcting raw image data and the raw image data; The first correction image data, the first correction image data, and the second conversion data set of the previous frame are converted into first correction image data by correcting the original image data input using the first conversion data set A timing controller for converting the first corrected image data into second corrected image data using the first corrected image data; A data driver receiving the second corrected image data and selecting and outputting a gradation voltage corresponding to the second corrected image data; And And a liquid crystal panel for displaying an image according to a voltage level of the gradation voltage, Wherein the graphics controller provides the first transformed data set and the second transformed data set in a frame blank period in which the original image data is not provided. delete 13. The method of claim 12, Wherein the first set of transformed data comprises a plurality of first transformed data corresponding one-to-one to a plurality of the original image data, wherein the raw image data is m bits and the first transformed data is n bits (n & , And the second set of converted data includes a plurality of second converted data corresponding to a pair of the first corrected image data and the first corrected image data of the previous frame. 15. The method of claim 14, The original gamma curve is a curve having a transmittance corresponding to the gray of the raw image data and the target gamma curve is a curve having a transmittance different from the transmittance of the original gamma curve corresponding to the gray of the raw image data, When there is a specific transmittance on the target gamma curve corresponding to the gray of the target gamma curve, Wherein the gray of the first converted data is gray corresponding to the specific transmittance on the raw gamma curve. delete 15. The method of claim 14, The timing controller includes: A first memory unit for storing the first conversion data set, A second memory unit for storing the second conversion data set, A gamma conversion unit that receives the raw image data and outputs the n-bit converted data corresponding to the raw image data in the first converted data set; A dithering processor for receiving the n-bit converted data and outputting the first corrected image data of m bits, When the difference between the gray of the first corrected image data and the gray of the first corrected image data of the previous frame is equal to or greater than a reference value, the first corrected image data and the first corrected image data of the previous frame And a data conversion unit for converting the first corrected image data into the second corrected image data using the second converted data corresponding to the combination of the first corrected image data and the second corrected image data. delete delete delete delete delete

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