KR20100000125A - Driving apparatus for liquid crystal display device and method for driving the same - Google Patents

Abstract

PURPOSE: A driving apparatus for liquid crystal display device and method for driving the same are provided to save the manufacturing cost of the liquid crystal display. CONSTITUTION: The liquid crystal panel(2) comprises a plurality of pixel regions. The position information of the small area and the area is outputted. According to the brightness information of the image information which the timing controller(8) is analyzed, the dimming control signal is created. The backlight unit(18) examines the light in response to the on timing control signal in the liquid crystal panel with the dimming control signal.

Description

DRIVING APPARATUS FOR LIQUID CRYSTAL DISPLAY DEVICE AND METHOD FOR DRIVING THE SAME

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a driving device and a driving method of the liquid crystal display device capable of reducing the manufacturing cost of the liquid crystal display device and improving image quality by preventing display defects.

Recently, flat panel display devices that are emerging include liquid crystal displays, field emission displays, plasma display panels, and light emitting displays.

Among the flat panel displays, liquid crystal displays are actively applied to notebooks, desktop monitors, and mobile terminals due to their excellent resolution, color display, and image quality.

The liquid crystal display displays a desired image by adjusting the transmittance of light emitted from the backlight unit according to the image signal. To this end, the liquid crystal display includes a liquid crystal panel having a plurality of liquid crystal cells for displaying an image, a driving circuit for driving the liquid crystal panel, a backlight unit for irradiating light to the liquid crystal panel, and the like.

 In the related art, a backlighting driving technique is used in which a backlight unit generates light of a constant brightness at a constant cycle regardless of an image signal. However, in the case of using the blinking driving technology, there is a problem that a motion blur or a ghost phenomenon occurs while the power consumption increases.

Accordingly, recently, a scanning driving technique that sequentially flashes the light sources of the backlight unit is applied. Here, the scanning driving technique is a technique for sequentially driving a plurality of lamps provided in the backlight unit along the scanning direction of the display line. However, when the scanning driving technique is applied, the time for generating light is reduced, the luminance is lowered, and the manufacturing cost increases because a plurality of inverters must be provided to correspond to the plurality of lamps sequentially generating light.

In other words, in the case of applying the blinking backlight unit in the related art, the image quality is lowered due to the ghost phenomenon while the power consumption is increased. Problems such as rising.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a driving apparatus and a driving method thereof for reducing the manufacturing cost of the liquid crystal display and improving image quality by preventing a display defect. Its purpose is to.

According to an aspect of the present invention, there is provided a driving apparatus of a liquid crystal display device including: a liquid crystal panel having a plurality of pixel regions; A graphic system for sequentially comparing image data input from the outside in units of frames and outputting location information of a large contrast area and a small region; A timing controller analyzing luminance information of the image data, generating a dimming control signal according to the analyzed luminance information, and receiving respective position information according to the contrast; and generating an on-timing control signal; And a backlight unit radiating light to the liquid crystal panel in response to the dimming control signal and the on-timing control signal.

The timing controller analyzes the luminance information of the image data, gamma-converts the image data according to the analyzed luminance information, generates conversion data, and generates a brightness control signal to correspond to the analyzed luminance information; The duty ratio is converted to correspond to the brightness control signal to generate the dimming control signal, and at least one of the synchronization signals input from the outside and the on / off position according to the position information of the region having a large contrast ratio and a small region. And a dimming control unit for generating a timing control signal and supplying the timing control signal to the backlight unit, respectively.

The image processor detects luminance information of the image data and sequentially outputs the luminance detector; a histogram generator configured to generate the histogram by storing the sequentially output luminance information in at least one frame unit, and every frame unit through the histogram. An image analyzer for reading a luminance value of one of a maximum luminance value, a minimum luminance value, an average luminance value, and a luminance value having a maximum frequency as histogram information and generating a gamma conversion signal and the brightness control signal according to the histogram information. And an image converter configured to generate grayscale values of the video data according to the gamma conversion signal to generate and output the converted data.

The dimming control unit counts the vertical synchronizing signal and the data enable signal among the synchronization signals to determine the location of the high contrast area and the low contrast area, and determines the position information or the small area of the high contrast area. The on-timing control signal is generated such that a backlight unit light generation timing is delayed according to the position information of.

The backlight unit includes a backlight having a plurality of light sources for generating light in the liquid crystal panel and an optical unit for improving the efficiency of light incident from the respective light sources, and generating a PWM signal according to the dimming control signal and generating the on-timing control. An inverter controller for controlling the output timing of the PWM signal according to the signal, and generating an AC driving signal for simultaneously driving the respective light sources in response to the output-controlled PWM signal and simultaneously supplying the same to the plurality of light sources. An inverter is provided.

In addition, the driving method of the liquid crystal display according to the embodiment of the present invention for achieving the above object is to output the position information of the region with a large contrast and a small region by sequentially comparing the image data input from the outside in units of frames Making; Analyzing the brightness information of the image data to generate a dimming control signal according to the analyzed brightness information and to generate an on-timing control signal using respective position information according to the contrast; And irradiating light to the liquid crystal panel in response to the dimming control signal and the on-timing control signal.

Generating the dimming control signal and the ON timing control signal by gamma-converting the image data according to the analyzed luminance information to generate converted data; generating a brightness control signal to correspond to the analyzed luminance information; The duty ratio is converted to correspond to the brightness control signal to generate the dimming control signal, and the ON according to the position information of at least one signal among the synchronization signals input from the outside and the region having a large contrast and a small region. Generating a timing control signal.

The generating of the converted data and the brightness control signal may include sequentially outputting the brightness information, generating the histogram by storing the sequentially output brightness information in at least one frame unit, and maximum each frame in the histogram. Reading a luminance value of one of a luminance value, a minimum luminance value, an average luminance value, and a luminance value having a maximum frequency as histogram information, and generating a gamma conversion signal and the brightness control signal to respectively correspond to the histogram information. And converting the grayscale value of the image data according to the gamma conversion signal to generate the converted data.

The generating of the on-timing control signal includes counting a vertical synchronization signal and a data enable signal among the synchronization signals to determine positions of the high contrast region and the low contrast region, and the high contrast ratio. And generating the on-timing control signal such that the backlight unit light generation timing is delayed according to the position information of the region or the position information of the small region.

The irradiating light to the liquid crystal panel may include generating a PWM signal according to the dimming control signal and controlling an output timing of the PWM signal according to the on-timing control signal, and responding to the PWM signal whose output timing is controlled. Generating an AC drive signal for simultaneously driving a plurality of light sources provided in the backlight; and simultaneously supplying the AC drive signal to the plurality of light sources.

As described above, the driving apparatus and the driving method of the liquid crystal display according to the present invention have the following effects.

That is, the driving device and the driving method of the liquid crystal display according to the embodiment of the present invention uses a blinking backlight unit having a minimum number of inverters to turn on / off a plurality of lamps simultaneously. The manufacturing cost can be reduced. In addition, by delaying or immediately outputting the PWM signal according to regions having a large or small image contrast between frames, it is possible to improve display quality by preventing display defects.

Hereinafter, a driving apparatus and a driving method thereof of a liquid crystal display according to an exemplary embodiment of the present invention having the above characteristics will be described in detail with reference to the accompanying drawings.

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

1 includes a liquid crystal panel 2 formed with a plurality of pixel regions; A data driver 4 for driving the plurality of data lines DL1 to DLm; A gate driver 6 driving a plurality of gate lines GL1 to GLn; A graphic system 10 for sequentially comparing image data RGB input from the outside in frame units and outputting position information Hh and Hs of a large contrast area and a small region; The luminance information of the image data RGB supplied through the graphic system 10 is analyzed to generate a dimming control signal Dim according to the analyzed luminance information, and position information Hh and Hs according to the contrast. ) A timing controller 8 for receiving the inputs and generating the on-timing control signal Ts; And a backlight unit 18 irradiating light to the liquid crystal panel 2 in response to the dimming control signal Dim and the on-timing control signal Ts.

Here, the timing controller 8 gamma-converts the grayscale value of the image data RGB according to the analyzed luminance information, and then supplies the data to the data driver 4 by aligning the grayscale value to be suitable for driving the liquid crystal panel 2. The gate and data control signals GCS and DCS are generated using the synchronization signals DCLK, Hsync, Vsync and DE input from the graphics system 10, and the generated gate and data control signals GCS and DCS are generated. Supply to gate and data driver 6,4, respectively.

The liquid crystal panel 2 includes a thin film transistor (TFT) formed in each pixel area defined by the plurality of gate lines GL1 through GLn and the plurality of data lines DL1 through DLm, and a liquid crystal capacitor connected to the TFT. (Clc). The liquid crystal capacitor Clc is composed of a pixel electrode connected to a TFT, and a common electrode facing each other with the pixel electrode and the liquid crystal interposed therebetween. The TFT supplies the image signals from the respective data lines DL1 to DLm to the pixel electrodes in response to the scan pulses from the respective gate lines GL1 to GLn. The liquid crystal capacitor Clc charges the difference voltage between the image signal supplied to the pixel electrode and the common voltage supplied to the common electrode, and adjusts the light transmittance by varying the arrangement of liquid crystal molecules according to the difference voltage. The storage capacitor Cst is connected to the liquid crystal capacitor Clc in parallel so that the voltage charged in the liquid crystal capacitor Clc is maintained until the next data signal is supplied. The storage capacitor Cst is formed by overlapping the pixel electrode with the previous gate line and the insulating layer interposed therebetween. In contrast, the storage capacitor Cst is formed by overlapping the pixel electrode with the storage line and the insulating layer interposed therebetween.

The data driver 4 includes a data control signal DCS from the timing controller 8, for example, a source start pulse (SSP), a source shift clock (SSC), and a source output enable (SCS). The conversion data MData input from the timing controller 8 is converted into an analog voltage, that is, an image signal, using a source output enable (SOE) signal or the like. Specifically, the data driver 4 performs gamma conversion through the timing controller 8 to latch the input conversion data MData according to the SSC, and then scan pulses to the gate lines GL1 to GLn in response to the SOE signal. For each horizontal period supplied with P, one horizontal line of video signals is supplied to each of the data lines DL1 through DLm. At this time, the data driver 4 selects a positive or negative gamma voltage having a predetermined level according to the gray value of the conversion data MData, and supplies the selected gamma voltage to each data line DL1 to DLm as an image signal. do.

The gate driver 6 includes a gate control signal GCS from the timing controller 8, for example, a gate start pulse (GSP), a gate shift clock (GSC), and a gate output enable (GSC). Scan pulses are sequentially generated in response to a GOE (Gate Output Enable) signal, and are sequentially supplied to the gate lines GL1 to GLn. In other words, the gate driver 6 shifts the GSP from the timing controller 8 according to GSC to sequentially supply scan pulses, for example, gate-on voltages, to the gate lines GL1 to GLn. The gate-off voltage is supplied to the gate lines GL1 to GLn during the period when the gate-on voltage is not supplied. Here, the gate driver 6 controls the pulse width of the scan pulse in accordance with the GOE signal.

The graphics system 10 sequentially compares image data RGB input from the outside in units of frames and outputs position information Hh and Hs of a large contrast area and a small region. Here, the position information Hh of the region having high contrast is sequentially compared with the image data of the previous frame and the image data of the current frame in units of at least one horizontal line, and the position information of the region where the brightness difference is greatest. The position information Hs of the region having a low contrast is sequentially compared with the image data of the previous frame and the image data of the current frame in units of at least one horizontal line, and the position information of the region where the brightness difference is smallest.

The timing controller 8 extracts luminance information of the image data RGB input through the graphic system 10, and generates converted data MData by gamma-converting the image data RGB to correspond to the extracted luminance information. do. Then, the conversion data MData is aligned so as to be suitable for driving the liquid crystal panel 2, and a data driver is supplied. In addition, the timing controller 8 generates a dimming control signal (Dim) for driving the backlight unit 18 to correspond to the extracted luminance information, and also has a large contrast from the graphic system 10. The position information Hh and Hs of the region and the small region are received, and the on-timing control signal Ts is generated and supplied to the backlight unit 18. As described above, the timing controller 8 includes a synchronization signal input through the graphic system 10, that is, a dot clock DCLK, a data enable signal DE, and horizontal and vertical synchronization signals Hsync and Vsync. The gate and data control signals GCS and DCS for controlling the gate and data drivers 6 and 4 are generated using at least one. The configuration and driving method of the timing controller 8 will be described later in more detail with reference to the accompanying drawings.

The backlight unit 18 includes a plurality of light sources for generating light to the liquid crystal panel 2 and a dimming control from the timing controller 8 and a backlight 12 having an optical unit for improving the efficiency of light incident from the respective light sources. An inverter controller 14 generating a pulse width modulation (PWM) signal according to the signal Dim and controlling an output timing of the PWM signal according to the on-timing control signal, and a PWM signal whose output timing is controlled In response, the inverter 16 generates an AC driving signal ADS for simultaneously driving the respective light sources and supplies the same to the plurality of light sources.

Here, as a light source of the backlight 12, cylindrical lamps such as Cold Cathode Fluorescent Lamp (CCFL), External Electrode Fluorescent Lamp (EEFL), etc. are mainly used. The lamps generate light by the AC drive signal ADS from the inverter 16. For example, in the case of the blinking backlight unit 18, light is generated by simultaneously turning on / off a plurality of cylinder-type lamps according to the AC driving signal ADS. In addition, the optical unit improves the light efficiency by diffusing and condensing the incident light from the light source.

The inverter controller 14 generates a PWM signal from the timing controller 8 to correspond to the dimming control signal Di with the duty ratio converted, and controls the output timing of the PWM signal to correspond to the on-timing control signal Ts. . Specifically, in the PWM signal according to the present invention, the on / off period of the lamp, for example, the high / low period is varied according to the duty ratio of the dimming control signal Dim. In addition, the PWM signal having a high / low period variable may be directly supplied to the inverter 16 or delayed according to the on-timing control signal Ts. The operation of the inverter controller 14 will be described in more detail with reference to the accompanying drawings.

The inverter 16 generates an AC drive signal ADS for driving the lamps, and at this time, the AC drive signal ADS is supplied or cut off according to the PWM signal from the inverter controller 14 to simultaneously turn on / off the lamps. Drive in Burst Mode to turn off.

FIG. 2 is a configuration diagram illustrating the timing controller shown in FIG. 1.

The timing controller 8 illustrated in FIG. 2 analyzes the luminance information YRGB of the image data RGB and gamma-converts the image data RGB according to the analyzed luminance information YRGB to generate converted data MData. In addition, by using the image processing unit 22 and the synchronization signals DCLK, Hsync, Vsync, and DE from the graphic system 10 to generate the brightness control signal BRI to correspond to the analyzed luminance information YRGB. The control signal generator 24 generating the gate and data control signals GCS and DCS and the duty ratio are converted to correspond to the brightness control signal BRI to generate a dimming control signal, and the synchronization signal DCLK, Generates an on-timing control signal Ts according to at least one signal of the Hsync, Vsync, and DE, and the position information Hh and Hs of the region having a large contrast and the region of the contrast and transmits the on-timing control signal Ts to the backlight unit 10. The dimming control part 26 which supplies each is provided.

The image processor 22 detects the luminance information YRGB of the image data RGB input from the graphic system 10 and sequentially outputs the luminance information 32 and the luminance information sequentially input from the luminance detector 32. The histogram generator 34 generating the histogram by storing (YRGB) in at least one frame unit, and the maximum luminance value, the minimum luminance value, and the average luminance value every frame unit through the histogram generated by the histogram generator 34. Or an image analyzer 36 for reading a luminance value having the maximum frequency as histogram information HI and generating a gamma conversion signal GS and a brightness control signal BRI according to the histogram information HI, and image analysis. The grayscale value of the image data RGB supplied through the graphic system 10 or the luminance detector 32 is converted according to the gamma conversion signal GS from the unit 36 to convert the converted data MData. And an image converter 38 for outputting.

The luminance detector 32 receives image data RGB sequentially input from the graphic system 10 and sequentially detects luminance values YRGB of red (R), green (G), and blue (B) pixels. do. Here, the luminance values YRGB of the red (R), green (G), and blue (B) pixels may be obtained by Equation 1 below.

YR = 0.299 × R

YG = 0.587 × G

YB = 0.114 × B

The histogram generator 34 generates the histogram as shown in FIG. 3 by sequentially storing the luminance value YRGB, which is sequentially input from the luminance detector 32, in at least one frame unit. In this case, the histogram generator 34 may include a plurality of counters sequentially arranged in place of the memory to sequentially store the luminance value YRGB.

The image analyzer 36 may generate the luminance value of one of the luminance value having the maximum luminance value, the minimum luminance value, the average luminance value, and the maximum frequency in every frame through the histogram generated by the histogram generator 34 as shown in FIG. 3. Read as histogram information (HI). The gamma conversion signal GS and the brightness control signal BRI are generated according to the histogram information HI. Here, the brightness control signal BRI indicates a brightness value set to correspond to the histogram information HI. In other words, the image analyzer 36 outputs a higher brightness control signal BRI as the image of the current frame is brighter and a lower brightness control signal BRI as the image of the current frame is darker. Done. In addition, the gamma conversion signal GS may refer to a gamma value preset according to the histogram information HI. In detail, the image analyzer 36 sets a gamma value to determine whether the image of the current frame is a bright image or a dark image according to the read histogram information HI. Accordingly, a high gamma value is output as the gamma conversion signal GS so that the darker the image is darker, and a low gamma value is output as the gamma conversion signal GS so that the brighter image is brighter.

As illustrated in FIG. 4, the image converting unit 38 is configured to determine the image data RGB input from the external or luminance detector 32 according to the gamma conversion signal GS input from the image analyzing unit 36. The gray value is gamma-converted and the converted data MData is supplied to the data driver 4. For example, when the gamma conversion signal GS from the image analyzer 36 is set to any one of 0.6, 1.0, 2.2, and 2.4 as the gamma value, the image converter 38 inputs the image data to correspond to the set gamma value. Gamma-converts the grayscale values of (RGB). The gamma-converted image data Ro, Go, and Bo may be aligned and aligned with the size of the liquid crystal panel 2 using at least one signal from the external synchronization signals DCLK, Hsync, Vsync, and DE. The obtained data is supplied to the data driver 4 as converted data (MData).

Meanwhile, a delay unit (not shown) may be further provided at the previous stage of the image converter 38. Here, the delay unit delays the image data RGB input through the external or luminance detector 32 to be synchronized with the period during which the histogram information HI is detected every frame. The delayed data may be supplied to the image converter 38.

The dimming controller 26 is a dimming control signal Di for converting a duty ratio to correspond to the brightness value of the image input from the image analyzer 36, that is, the brightness control signal BRI. Create Specifically, the dimming control unit 26 first calculates the duty ratio according to the brightness control signal BRI, and then sets the driving period of the lamps, that is, the lamp on period, to correspond to the calculated duty ratio. ) The generated dimming control signal Dim is supplied to the inverter controller 14. Accordingly, when the duty ratio of the dimming control signal Dim is set to 70%, the plurality of lamps may be turned on simultaneously for 70% of one frame period, and the plurality of lamps may be turned off simultaneously for the remaining 30% period of time. have.

In addition, the dimming control unit 26 may include at least one of the synchronization signals DCLK, Hsync, Vsync, and DE received from the graphics system 10, and position information Hh and Hs of a region having a large contrast and a small region. The on-timing control signal Ts is generated and supplied to the inverter controller 14 together with the dimming control signal Dim. In detail, the dimming control unit 26 counts the vertical synchronization signal Vsync and the data enable signal DE to determine the positions Hh and Hs of the region having high contrast and the region having low contrast. The on-timing control signal Ts is generated and output so that the on timing of the lamp is delayed according to at least one of the position information Hh of the region having a large contrast and the position information Hs of the small region.

In FIG. 2, the control signal generator 24 generates gate and data control signals GCS and DCS by using the synchronization signals DCLK, Hsync, Vsync, and DE received from the graphics system 10. The data control signals GCS and DCS are supplied to the gate driver 6 and the data driver 4, respectively.

5 is a waveform diagram illustrating a method of driving the backlight unit illustrated in FIG. 1.

As shown in FIG. 5, in the n frame period nFrame, the inverter controller 14 generates a PWM signal to have a duty ratio of 60% according to the dimming control signal Dim from the dimming controller 26. In response to the on-timing control signal Ts set to be delayed during the D1 period, the PWM signal is delayed for the D1 period and then the PWM signal is supplied to the inverter 16 (PWM output). At this time, the inverter 16 supplies the lamp driving voltage ADS to the plurality of lamps so as to be synchronized with the high period of the PWM signal, and the plurality of lamps generate light during the period in which the lamp driving voltage ADS of AC is supplied. Done. Here, the low period of the PWM signal is a period in which the lamps are off.

Next, in the n + 1 frame period n + 1Frame, the inverter controller 14 generates a PWM signal to have a duty ratio of 50% according to the dimming control signal Dim from the dimming control unit 26, The PWM signal is delayed during the D2 period in response to the on-timing control signal Ts set to be delayed during the D2 period, and then the PWM signal is supplied to the inverter 16 (PWM output). At this time, the inverter 16 supplies the lamp driving voltage ADS to the plurality of lamps so as to be synchronized with the high period of the PWM signal, and the plurality of lamps generate light during the period in which the lamp driving voltage ADS of AC is supplied. do. In this case, as shown in FIG. 6 (a), the timing at which the lamps are turned on after a delay for the period D2, that is, a ghost phenomenon such as overlapping of images in a region having a large image contrast between frames is reduced to improve image quality. Can be.

In the n + 2 frame period n + 2Frame, the inverter control unit 14 generates a PWM signal to have a duty ratio of 40% according to the dimming control signal Dim from the dimming control unit 26. The PWM signal is immediately supplied to the inverter 16 without delay in response to the on-timing control signal Ts set to output the PWM signal without delay. At this time, the inverter 16 supplies the lamp driving voltage ADS to the plurality of lamps so as to be synchronized with the high period of the PWM signal, and the plurality of lamps generate light during the period in which the lamp driving voltage ADS of AC is supplied. do. In this case, as shown in FIG. 6B, the timing at which the lamps are turned on, that is, the ghost phenomenon such as overlapping of images in a region having a large image contrast between frames may be deteriorated, thereby improving image quality.

As described above, the driving apparatus and driving method of the liquid crystal display according to the exemplary embodiment of the present invention provide a liquid crystal by using a blinking backlight unit having a minimum number of inverters to turn on / off a plurality of lamps simultaneously. The manufacturing cost of the display device can be reduced. In addition, by delaying or immediately outputting the PWM signal according to regions having a large or small image contrast between frames, it is possible to improve display quality by preventing display defects.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

1 is a configuration diagram showing a driving device of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating the timing controller shown in FIG. 1. FIG.

3 is a histogram of one frame calculated from the histogram generator of FIG.

4 is a graph illustrating an output gray level compared to an input gray level stored in the image converter of FIG. 2 according to a gamma value.

5 is a waveform diagram illustrating a method of driving the backlight unit illustrated in FIG. 1.

6 is a screen showing the effects of the present invention.

* Brief description of symbols for the main parts of the drawings.

2: liquid crystal panel 4: data driver

6: gate driver 8: timing controller

10: graphics system 12: back light

14: inverter control unit 16: inverter

18: backlight unit 22: image processing unit

24: control signal generator 26: dimming controller

32: luminance detector 34: histogram generator

36: image analysis unit 38: image conversion unit

Claims (10)

A liquid crystal panel formed with a plurality of pixel regions; A graphic system for sequentially comparing image data input from the outside in units of frames and outputting location information of a large contrast area and a small region; A timing controller analyzing luminance information of the image data, generating a dimming control signal according to the analyzed luminance information, and receiving respective position information according to the contrast; and generating an on-timing control signal; And And a backlight unit for irradiating light to the liquid crystal panel in response to the dimming control signal and the on-timing control signal. The method of claim 1, The timing controller is An image processor which analyzes the luminance information of the image data and gamma-converts the image data according to the analyzed luminance information to generate converted data, and generates a brightness control signal to correspond to the analyzed luminance information; The duty ratio is converted to correspond to the brightness control signal to generate the dimming control signal, and the ON according to the position information of at least one signal among the synchronization signals input from the outside and the region having a large contrast and a small region. And a dimming control unit for generating a timing control signal and supplying the timing control signal to the backlight unit, respectively. The method of claim 2, The image processor A luminance detector for detecting and sequentially outputting luminance information of the image data; A histogram generator for generating a histogram by storing the sequentially output luminance information in at least one frame unit; A luminance value of one of a maximum luminance value, a minimum luminance value, an average luminance value, and a luminance value having a maximum frequency is read as histogram information through the histogram, and a gamma conversion signal and the brightness control signal according to the histogram information. An image analyzer for generating each, and And an image converter configured to convert the grayscale value of the image data according to the gamma conversion signal to generate and output the converted data. The method of claim 3, wherein The dimming control unit Counting the vertical synchronization signal and the data enable signal of the synchronization signal to determine the location of the region having a high contrast and the region having a low contrast, the position information of the region having a high contrast or the position information of the small region And the on-timing control signal is generated such that a backlight unit light generation timing is delayed. The method of claim 4, wherein The backlight unit is A backlight having a plurality of light sources for generating light in the liquid crystal panel and an optical unit for improving the efficiency of light incident from the respective light sources; An inverter controller configured to generate a PWM signal according to the dimming control signal and to control an output timing of the PWM signal according to the on-timing control signal; And an inverter which generates an AC driving signal for simultaneously driving the respective light sources in response to the PWM signal whose output timing is controlled and simultaneously supplies the same to the plurality of light sources. Outputting position information of a region having a large contrast and a small region by sequentially comparing image data input from the outside in units of frames; Analyzing the brightness information of the image data to generate a dimming control signal according to the analyzed brightness information and to generate an on-timing control signal using respective position information according to the contrast; And And irradiating light to the liquid crystal panel in response to the dimming control signal and the on-timing control signal. The method of claim 6, Generating the dimming control signal and the on timing control signal, Generating converted data by gamma-converting the image data according to the analyzed luminance information; Generating a brightness control signal to correspond to the analyzed luminance information, and The duty ratio is converted to correspond to the brightness control signal to generate the dimming control signal, and the ON according to the position information of at least one signal among the synchronization signals input from the outside and the region having a large contrast and a small region. And-generating a timing control signal. The method of claim 7, wherein The conversion data and brightness control signal generation step Sequentially outputting the luminance information; Generating a histogram by storing the sequentially output luminance information in at least one frame unit; Reading luminance values of one of a maximum luminance value, a minimum luminance value, an average luminance value, and a luminance value having a maximum frequency as histogram information in each frame unit through the histogram; Generating a gamma conversion signal and the brightness control signal to respectively correspond to the histogram information, and And converting the grayscale value of the image data according to the gamma conversion signal to generate the converted data. The method of claim 8, The on-timing control signal generation step, Counting a vertical sync signal and a data enable signal among the sync signals to determine the positions of the regions having high contrast and the regions having low contrast; and And generating the on-timing control signal to delay the backlight unit light generation timing according to the positional information of the region having a large contrast or the positional information of the small region. The method of claim 9, Irradiating light to the liquid crystal panel Generating a PWM signal according to the dimming control signal and controlling an output timing of the PWM signal according to the on-timing control signal; Generating an AC driving signal for simultaneously driving a plurality of light sources included in the backlight in response to the PWM signal whose output timing is controlled; and And simultaneously supplying the AC drive signal to the plurality of light sources.

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