KR20160076275A - Apparatus for converting image data and display device including the same - Google Patents

Abstract

Provided are an apparatus for converting image data and a display device including the same. Data distortion due to overshoot can be prevented by outputting correction image data generated by a gradual change in overdriving size in the same direction as the moving direction of an object from image data according to the movement level of the object. And, the generation of afterimages or motion blur on the boundary surface of a moving object can be prevented by improving a response speed in a moving image. The apparatus includes a first correction part, a second correction part, and a motion deciding part.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a video data conversion apparatus and a display device including the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video data conversion apparatus, and more particularly, to a video data conversion apparatus and a display apparatus including the same, capable of improving display quality by improving moving picture response time (MPRT).

The liquid crystal display displays an image by adjusting the light transmittance of each liquid crystal cell according to an input signal. To this end, the liquid crystal display device includes a liquid crystal panel in which liquid crystal cells are arranged in a matrix form, a backlight unit for supplying light to the liquid crystal panel, and a driving circuit for driving the liquid crystal panel and the backlight unit.

In recent years, users' demands for high-quality and realistic images have been increasing. In order to realize a high-quality image, there are various matters to be considered.

The liquid crystal of the liquid crystal display has a disadvantage in that the response speed is slow due to inherent characteristics such as viscosity and elasticity. Due to the slow response speed characteristic of the liquid crystal, the behavior of the liquid crystal does not completely end during a predetermined time (for example, during one frame). In this case, the image data of the next frame period is supplied to the liquid crystal cell before the luminance of the image corresponding to the image data supplied to the liquid crystal cell reaches the desired luminance in the previous frame period. Accordingly, in the screen of the liquid crystal display device, the image of the previous frame overlaps with the image of the next frame, resulting in a motion blur phenomenon in which the image is blurred with the after-image, resulting in degraded display quality. Such afterimage and motion blur phenomenon becomes worse when a moving image is displayed on a liquid crystal display.

In order to solve the problem of lowering the image quality according to the response speed of the liquid crystal, in the conventional liquid crystal display device, an over driving method of modulating the image data supplied to the liquid crystal panel to increase the response speed of the liquid crystal has been proposed. The over-driving method increases the response speed of the liquid crystal by increasing the size of the image data supplied to the liquid crystal panel so as to have a higher gradation level.

1A and 1B are diagrams showing an over-driving method of a conventional liquid crystal display device.

1A, when a liquid crystal panel is driven by a general driving method and image data of a first voltage level V1 is supplied during one frame period, the pixels of the liquid crystal panel are driven for several frame periods Delayed and charged. As a result, in the liquid crystal panel, the afterimage and the motion blur phenomenon become serious.

1B, the conventional liquid crystal display device supplies image data of the second voltage level V2 so as to have a higher gradation level during one frame period of the liquid crystal panel to increase the response speed of the liquid crystal, And the motion blur phenomenon.

However, when the size of the image data is excessively increased, an overshoot (A) occurs in the data signal as shown in FIG. 1B. Actual image data is distorted due to such overshoot Thereby degrading reliability.

The present invention provides an image data conversion apparatus and a display device including the image data conversion apparatus capable of minimizing data distortion while improving a moving image response speed to prevent image quality deterioration.

According to an aspect of the present invention, there is provided an image data conversion apparatus including a first compensation unit, a motion determination unit, a second compensation unit, and a selection unit.

The first compensation unit compares the N-th frame image data with the (N-1) th frame image data, and applies over-driving to the N-th frame image data according to the comparison result to generate first compensation data of increased size.

The motion determining unit compares the degree of motion of the object in the Nth frame image data and the (N-1) th frame image data, and generates motion information and a selection signal according to the comparison result.

The second compensation unit generates second compensation data that is gradually scaled from the first compensation data in accordance with the motion information.

The selector selects one of the first compensation data and the second compensation data according to the selection signal, and outputs the selected compensation data.

According to an aspect of the present invention, there is provided a display device including a liquid crystal panel, a timing controller, a gate driver, and a data driver.

The image data conversion apparatus according to the present invention can output the generated compensated image data by gradually decreasing the overdriving size in the same direction as the moving direction of the object from the image data according to the degree of motion of the object in the image.

Accordingly, it is possible to prevent an overshoot in the data signal from occurring due to the overdrived image data and to prevent the original data from being distorted. Also, it is possible to prevent the afterimage or motion blur can do. As a result, the display quality of the display device can be improved.

1A and 1B are diagrams showing an over-driving method of a conventional liquid crystal display device.
2 is a diagram illustrating a configuration of a liquid crystal display device according to an embodiment of the present invention.
3 is a diagram showing a specific configuration of the data conversion unit shown in FIG.
4 is a diagram specifically showing the second compensation unit shown in FIG.
5A to 5D are exemplary diagrams showing operations of the data conversion unit.
6A and 6B are diagrams showing a conventional over-driving method and an over-driving method of the present invention.

Hereinafter, a video data conversion apparatus and a display device including the same according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a diagram illustrating a configuration of a liquid crystal display device according to an embodiment of the present invention.

Referring to FIG. 2, the liquid crystal display 100 of the present embodiment may include a liquid crystal panel 110, a gate driver 120, a data driver 130, and a timing controller 140.

The liquid crystal panel 110 includes a plurality of gate lines GL and a plurality of data lines DL and includes a pixel P formed for each region defined by the intersection of the gate line GL and the data line DL, . ≪ / RTI > The pixel P may include a thin film transistor T, a liquid crystal capacitor Clc, and a storage capacitor Cst, which are formed at intersections of the gate line GL and the data line DL.

The thin film transistor T may supply the pixel P with a data signal, which is supplied through the data line DL, in response to a gate signal provided through the gate line GL. The data signal charged in the pixel P can be updated every time the thin film transistor T is turned on.

The liquid crystal panel 110 may include an array substrate (not shown) and a color filter substrate (not shown) bonded together with a liquid crystal layer (not shown) sandwiched therebetween. The gate line GL, the data line DL And the pixel P may be formed on the array substrate of the liquid crystal panel 110. [ A color filter (not shown) corresponding to the pixel P of the array substrate and a black matrix (not shown) for partitioning between the color filters may be formed on the color filter substrate.

The gate driver 120 may generate a gate signal in response to the gate control signal GCS output from the timing controller 140. [ The gate signal may be sequentially output to the plurality of gate lines GL of the liquid crystal panel 110 to enable the plurality of gate lines GL by one horizontal period 1H.

The gate driver 120 may include a shift register and a level shifter. The gate driver 120 may be formed in the liquid crystal panel 110 by a gate in panel (GIP) method.

The data driver 130 may generate a data signal from the image data output from the timing controller 140, for example, the compensated image data Data, according to the data control signal DCS output from the timing controller 140. [ The data signal may be output to the liquid crystal panel 110 through the plurality of data lines DL whenever the plurality of gate lines GL of the liquid crystal panel 110 are sequentially enabled.

The timing controller 140 receives the gate control signal GCS, the data control signal DCS and the compensation video data Data (Data) according to the video signals R, G, and B and the control signals CNT provided from an external system Can be generated and output. The timing controller 140 may include a control signal generator 145 and a data converter 141.

The control signal generator 145 may generate the gate control signal GCS and the data control signal DCS according to the control signal CNT provided from the external system. The gate control signal GCS may be output to the gate driver 120 and the data control signal DCS may be output to the data driver 130.

Here, the externally supplied control signal CNT may be timing signals such as a data clock signal DCLK, a horizontal synchronizing signal Hsync, a vertical synchronizing signal Vsync, and a data enable signal DE. The gate control signal GCS may include a gate start pulse GSP, a gate output enable signal GOE, a gate shift clock GSC, and the like. The data control signal DCS may include a source start pulse SSP, a source shift clock SSC, a source output enable SOE, a polarity control signal POL, and the like.

The data conversion unit 141 may generate and output the compensated image data Data from the image signals R, G, and B provided from the external system. The data conversion unit 141 generates image data from the image signals R, G, and B and then applies over-driving or under-driving to the generated image data, It is possible to generate the compensated image data Data in which the voltage level is increased or decreased.

The data conversion unit 141 may generate the compensated image data Data according to the degree of object motion of the image signals R, G, and B. Hereinafter, the configuration of the data conversion unit 141 will be described in detail with reference to the drawings.

3 is a diagram showing a specific configuration of the data conversion unit shown in FIG.

2 and 3, the data conversion unit 141 includes an image data generation unit 151, a delay unit 152, an image data compensation module 155, a motion determination unit 156, and a selection unit 157, . ≪ / RTI >

The image data generation unit 151 may generate image data RGB by rearranging the externally input image signals R, G, and B to match the liquid crystal panel 110. [ The image data (EGB) may be output in frame units.

The delay unit 152 may output the delayed image data RGB 'by delaying the image data RGB output from the image data generation unit 151 for one frame period.

For convenience of description, the image data RGB output from the image data generation unit 151 is the first image data of the current frame, and the delayed image data RGB 'output from the delay unit 152 is the previous image data As shown in FIG. Where N > = 1.

The image data compensation module 155 compares the first image data RGB with the second image data RGB and generates and outputs the compensated image data Data according to the comparison result. The compensated image data Data may be data in which a specific portion of the first image data RGB is subjected to overdriving or underdriving so that the magnitude, for example, the voltage level is adjusted. The image data compensation module 155 may include a first compensation unit 153 and a second compensation unit 154.

The first compensation unit 153 may generate the first compensation data RGB1 by comparing the first image data RGB and the second image data RGB '. The first compensator 153 compares the size difference between the corresponding data of the first image data RGB and the second image data RGB and adjusts the size of the first image data RGB according to the comparison result. To generate the first compensation data RGB1.

The second compensating unit 154 may re-adjust the size of the first compensation data RGB1 to generate the second compensation data RGB2. The second compensator 154 may generate the second compensation data RGB2 according to the motion information MI output from the motion determiner 156. [

Here, the second compensator 154 may generate the second compensation data RGB2 by adjusting the magnitude of the first compensation data RGB1 to gradually decrease or increase according to the motion information MI.

The first compensation data RGB1 can be maintained at the same level for one frame period. Further, the second compensation data RGB2 can be maintained at different levels during one frame period.

For example, when the data signal to be output to three data lines DL among the current frame image data, that is, the first image data RGB, is generated from overdrived compensated image data Data having the same size, Unit 153 can generate three pieces of first compensation data RGB1 whose size is increased to the same level during one frame period. However, the second compensation unit 154 may generate three second compensation data RGB2 whose magnitudes gradually change over one frame period from the first compensation data RGB1.

4 is a diagram specifically showing the second compensation unit shown in FIG.

3 and 4, the second compensation unit 154 may include an adjustment ratio generating unit 161 and a data generating unit 165).

The adjustment ratio generator 161 may generate one or more adjustment factors [Delta] V according to the motion information MI. The adjustment ratio DELTA V is a value for adjusting the size of the first compensation data RGB1 and may be generated by gradually increasing or decreasing the magnitude of the ratio when a plurality of adjustment rates DELTA V are generated . Here, the plurality of adjustment ratios? V can be generated by increasing or decreasing the motion information MI in the same direction as the moving direction of the object. Also, the plurality of adjustment ratios? V can be generated in the same number as the moving distance of the object among the motion information MI. For example, if the object has been moved by three pixels, three adjustment ratios? V can be generated.

On the other hand, the adjustment ratio generator 161 may include a lookup table (not shown) therein, and may select and output a corresponding adjustment ratio? V from the lookup table according to the motion information MI.

The data generator 165 may generate the second compensation data RGB2 by re-adjusting the magnitude of the first compensation data RGB1 according to the adjustment ratio? V output from the adjustment ratio generator 161. [ Since the adjustment ratio DELTA V is generated in such a manner that the adjustment ratio DELTA V is gradually increased or decreased according to the moving direction and moving distance of the object of the motion information MI, The second compensation data RGB2 can be generated.

Referring again to FIG. 3, the motion determiner 156 may generate motion information (MI) by comparing motion levels of objects included in the first image data RGB and the second image data RGB ' . The motion information MI may include an object moving direction, a moving distance, a moving speed, and the like.

The motion determiner 156 may generate and output one of the first level select signal SC and the second level select signal SC by comparing the object moving distance of the motion information MI with a reference value. For example, the motion determination unit 156 outputs the first level selection signal SC when the object movement distance is greater than the reference value, and outputs the second level selection signal SC when the object movement distance is less than the reference value. The selection signal SC may be composed of 1-bit data.

The selection unit 157 may select one of the first compensation data RGB1 and the second compensation data RGB2 according to the selection signal output from the motion determiner 156 and output the selected compensation data as the compensation video data Data . For example, when the motion determination unit 156 outputs the first level selection signal SC, the selection unit 157 can select and output the second compensation data RGB2. When the motion determination unit 156 outputs the second level selection signal SC, the selection unit 157 can select and output the first compensation data RGB1.

5A to 5D are exemplary diagrams showing operations of the data conversion unit.

Hereinafter, the operation of generating the compensated image data Data in the data converter 141 of the present embodiment will be described in detail with reference to FIGS. 3 to 5D. For convenience of explanation, the data conversion unit 141 generates compensation data to which overdriving is applied, for example. However, the present invention can also be applied to generating compensation data to which under-driving is applied by the data conversion unit 141. [

First, when the video signals R, G, and B are input from the external system, the video data generation unit 151 of the data conversion unit 141 generates video data R, G, and B from the video signals R, It is possible to generate and output image data, that is, first image data (RGB). The delay unit 152 may output the image data of the previous frame ((N-1) Frame), that is, the second image data RGB '.

As shown in FIG. 5A, the first image data RGB and the second image data RGB 'may include objects Ob and Ob', respectively. At this time, the object Ob 'of the first image data RGB has a first distance d of 3 pixels in the first horizontal direction than the object Ob of the second image data RGB' (d). Here, each of the objects Ob and Ob 'may have a high gradation level, for example, a white component, and the background of each image data RGB, RGB' may have a low gradation level, .

The first compensation unit 153 may generate the first compensation data RGB1 by comparing the first image data RGB and the second image data RGB '. The first compensation data RGB1 is set such that the size of the data applied to the portion where the gradation level is changed by the moved object Ob 'in the first image data RGB, that is, the data line corresponding to 3 pixels in the horizontal direction is increased Can be regulated. The first compensation unit 153 can generate three pieces of first compensation data RGB1 whose sizes are larger than the original data, that is, the first image data RGB.

The motion determiner 156 may generate motion information MI according to the degree of motion of the object Ob 'by comparing the first image data RGB and the second image data RGB'. The motion determiner 156 may generate the selection signal SC by comparing the motion information MI with a reference value. Here, since the object Ob 'is shifted by 3 pixels in the first horizontal direction from the first image data RGB, the motion determining unit 156 may generate the first level selection signal SC.

The second compensator 154 may generate the second compensation data RGB2 from the first compensation data RGB1 according to the motion information MI.

The adjustment ratio generator 161 of the second compensation unit 154 may generate the adjustment ratio as many as the number of pixels corresponding to the object moving distance of the motion information MI, that is, three adjustment ratios? V. At this time, the adjustment ratio generator 161 may generate three adjustment rates? V whose magnitudes are gradually reduced in the same direction as the object moving direction of the motion information MI.

The data generating unit 165 of the second compensating unit 154 applies the decreasing rate of the first compensation data RGB1 according to the three adjustment rates? , It is possible to generate three pieces of second compensation data RGB2 that gradually increase in size.

That is, the magnitude of the adjustment ratio (? V) and the magnitude of the second compensation data (RGB2) can be respectively generated in an inversely proportional relationship, whereby the adjustment ratio generation unit (161) Once generated, the data generation unit 165 may generate second compensation data RGB2 reduced in size to a small width from the first compensation data RGB1.

Meanwhile, the second compensation data RGB2 shown in FIG. 5D is generated with the same size as the first compensation data RGB1. However, the second compensation data RGB2 shown in FIG. 5C is generated with a size (V4-V3) smaller than the first compensation data RGB1. In addition, the second compensation data RGB2 shown in Fig. 5B is also generated with a magnitude (V4-V2) smaller than the first compensation data RGB1. At this time, the second compensation data RGB2 shown in FIG. 5B is generated with a smaller size than the second compensation data RGB2 shown in FIG. 5C.

5B to 5D, the second compensating unit 154 may include three second compensating data RGB2 (see FIG. 5B) which are gradually increased in the same direction as the object moving direction according to the motion information MI, Can be generated.

The selection unit 157 selects the second compensation data RGB2 according to the first level selection signal SC output from the motion determination unit 156 and supplies the second compensation data RGB2 to the data driver 130 Can be output.

The data driver 130 may generate and output a data signal applied to the data line corresponding to three pixels in the horizontal direction according to the compensated image data Data. At this time, the data driver 130 may output the data signal generated from the second compensation data RGB2 shown in FIG. 5B to the data line corresponding to the first pixel among the 3 pixels in the horizontal direction. In addition, a data signal generated from the second compensation data RGB2 shown in FIG. 5C can be output to the data line corresponding to the second pixel among 3 pixels in the horizontal direction. In addition, a data signal generated from the second compensation data RGB2 shown in FIG. 5D can be output to a data line corresponding to a third pixel among 3 pixels in the horizontal direction.

As described above, the data conversion unit 141 of the present embodiment generates the compensation data, i.e., the second compensation data (RGB2) to which overdriving is applied in which the size gradually increases in accordance with the motion of the object in the image, It is possible to prevent the afterimage and the motion blur which are generated when the overdriving compensation data is outputted to the same level according to the motion of the driver. Therefore, the liquid crystal display device 100 according to the present invention can improve the moving image response speed, thereby improving the display quality. In addition, it is possible to prevent an overshoot from occurring in the data signal due to the overdrived compensation data, and to prevent the data from being distorted.

6A and 6B are diagrams showing a conventional over-driving method and an over-driving method of the present invention.

In the conventional overdriving method, the overdrived compensated image is increased so that the size of the first region (d) increases, for example, in a region where the gradation level is changed by movement of the object, And generates and outputs data.

Accordingly, in the conventional liquid crystal display device, the entire first region (d) rises from the existing G0 gradation level to the G1 gradation level as shown in Fig. 6A. Accordingly, a residual image and a motion blur phenomenon are generated in the first area (d) by the moving object in the area (d), and the display quality is degraded. In the conventional liquid crystal display device, overshoot (A) of the data signal is generated in the first region (d), and the displayed data may be distorted.

However, the over-driving method according to the present invention can generate and output the over-driven compensated image data Data so that the size gradually increases during one frame period according to the moving direction and the moving distance of the object.

Accordingly, in the liquid crystal display device of the present invention, as shown in Fig. 6B, the gradation level gradually rises from the existing G0 gradation level to the G1 gradation level in the first region (d). Accordingly, the afterimage and the motion blur phenomenon do not occur in the first region (d) due to the moving object in the region (d), thereby improving the display quality. In the liquid crystal display device of the present invention, overshoot of the data signal does not occur in the first region (d), and data distortion may not occur.

While a number of embodiments have been described in detail above, it should be construed as being illustrative of preferred embodiments rather than limiting the scope of the invention. Therefore, the invention should not be construed as limited to the embodiments described, but should be determined by equivalents to the appended claims and the claims.

100: liquid crystal display device 110: liquid crystal panel
120: Gate driver 130: Data driver
140: timing control section 141: data conversion section
143: Control signal generation unit 151:
152: delay unit 153: first compensation unit
154: second compensator 156: motion determiner
157: selection unit 161: adjustment ratio generation unit
165:

Claims (10)

(N-1) -th frame image data, and generates first compensation data having increased size by applying over-driving to the (N-1) -th frame image data according to a result of the comparison, ;
A motion determiner for comparing motion levels of the object in the N-th frame image data and the (N-1) -th frame image data, and generating motion information and a selection signal according to the comparison result;
A second compensation unit for generating second compensation data that is gradually changed in size from the first compensation data according to the motion information; And
And a selector for selecting one of the first compensation data and the second compensation data according to the selection signal and outputting the selected compensation data as compensated image data. The apparatus according to claim 1,
An adjustment ratio generator for generating at least one adjustment ratio according to the motion information; And
And a data generator for generating the second compensation data from the first compensation data according to the at least one adjustment ratio. 3. The method of claim 2,
Wherein the at least one adjustment ratio is generated by the number of pixels corresponding to the movement distance of the object. 3. The method of claim 2,
Wherein the at least one adjustment ratio is generated so as to gradually decrease in size in the same direction as the moving direction of the object. 5. The method of claim 4,
Wherein the second compensation data is generated so as to gradually increase in size from the first compensation data according to the at least one adjustment ratio. The method according to claim 1,
Wherein the motion determining unit compares the motion information with a reference value, outputs the selection signal having a first level or a second level according to a comparison result,
Wherein the selector selects the second compensation data according to the first level selection signal and selects the first compensation data according to the second level selection signal. The method according to claim 6,
Wherein the selection signal comprises 1-bit data. The method according to claim 1,
An image data generation unit for generating image data from the video signal and outputting the generated image data as the Nth frame image data; And
Further comprising a delay unit for delaying the video data by one frame period to output the (N-1) -th frame video data. The method according to claim 1,
Wherein the compensated image data is output during one frame period. A liquid crystal panel in which a plurality of pixels are arranged in a region defined by a plurality of gate lines and a plurality of data lines;
A timing control unit including a control signal generator for generating a gate control signal and a data control signal and a data converter for generating compensated image data from the video signal;
A gate driver for outputting a gate signal to the plurality of gate lines according to the gate control signal; And
And a data driver for generating a data signal from the compensated image data according to the data control signal and outputting the data signal to the plurality of data lines,
Wherein the data conversion unit comprises:
(N-1) -th frame image data, and generates first compensation data having increased size by applying over-driving to the (N-1) -th frame image data according to a result of the comparison, ;
A motion determiner for comparing motion levels of the object in the N-th frame image data and the (N-1) -th frame image data, and generating motion information and a selection signal according to the comparison result;
A second compensation unit for generating second compensation data that is gradually scaled from the first compensation data according to the motion information; And
And a selector for selecting one of the first compensation data and the second compensation data according to the selection signal and outputting the selected compensation data as the compensation video data.

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