KR20090002730A - Back light unit and liquid crystal display device using the same and driving method thereof - Google Patents

Abstract

A backlight unit and a liquid crystal display device using the same are provided to compensate color differences of light which is generated from the backlight unit. An inverter control part(14) compensates for the luminance value and the colour inputted from outside to the dimming value control signal, which is input from outside that is, the dimming control signal(Dim) produces the PWM(Pulse Width Modulation) signal. An inverter(16) produces the AC driving signal(ADS) in response to the PWM signal from the inverter control part. The backlight(12) includes a plurality of light sources and is generated the light according to the AC driving signal. The light detector detects one or more value among the luminance value from the backlight, and sends the detected value to the inverter controller.

Description

BACK LIGHT UNIT AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME AND DRIVING METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit. In particular, a backlight unit, a liquid crystal display using the same, and a liquid crystal display device using the same to compensate for color difference of each region with respect to light generated from the backlight can be improved. It relates to a driving method.

As the information society develops, the demand for image display devices is increasing in various forms. Recently, liquid crystal displays, field emission displays, plasma display panels, Various flat panel displays, such as a light emitting display, are utilized.

Among them, the liquid crystal display device displays a desired image by controlling the transmission amount of light supplied from the back light unit by a liquid crystal panel having a plurality of liquid crystal cells arranged in a matrix form. Specifically, the liquid crystal display obtains a desired image by forming an electric field in the liquid crystal layer according to the data signal to adjust the transmittance of light passing through the liquid crystal layer.

The backlight unit includes a backlight having a plurality of light sources for generating light, an inverter for driving each light source provided in the backlight, and an inverter driving circuit. Such a backlight may be classified into an edge type and a direct type backlight according to positions of respective light sources.

However, in the conventional edge-type and direct-type backlight, a plurality of light sources are driven in a bottom case, and light is generated according to an arrangement direction of each light source and a distance difference between each light source and the bottom case. There is a problem in that luminance and chromaticity are different for each of the regions. In particular, when using a light emitting diode (LED) as a light source, since the red (R), green (G), and blue (B) LEDs are arranged in sequence, the chromaticity and luminance of the outer and center regions of the backlight are shown. Will make a difference.

The present invention is to solve the above problems, a backlight unit and a liquid crystal display using the same to improve the display quality of the image by compensating for the color difference for each region of the light generated from the backlight It is an object of the present invention to provide a device and a method of driving the same.

According to an aspect of the present invention, there is provided a backlight unit comprising: an inverter controller configured to generate a PWM signal by compensating at least one of chromaticity and luminance values from the outside with a dimming control signal from the outside; An inverter generating an AC driving signal in response to the PWM signal; And a backlight having a plurality of light sources to generate light according to the AC driving signal, and to detect at least one of chromaticity and luminance values of the generated light and supply the light to the inverter controller. .

In addition, the driving method of the backlight unit according to an embodiment of the present invention for achieving the above object is to generate a PWM signal by compensating at least one of the chromaticity and luminance value from the outside to the dimming control signal from the outside Making; Generating an AC driving signal in response to the PWM signal; And generating light according to the AC driving signal and detecting and outputting at least one of chromaticity and luminance values of the generated light.

In addition, the liquid crystal display according to an embodiment of the present invention for achieving the above object is a liquid crystal panel formed with a plurality of pixels; A gate and data driver driving the plurality of pixels; A timing controller for supplying image data input from the outside to the gate and data driver and controlling the gate and data driver; And a backlight unit having the above-mentioned characteristics for irradiating light to the liquid crystal panel.

In addition, the driving method of the liquid crystal display device according to an embodiment of the present invention for achieving the above object is a liquid crystal display device having a liquid crystal panel having a plurality of pixels and a backlight unit for irradiating light to the liquid crystal panel. A method of driving a light source, the method comprising: displaying an image by adjusting light transmittance; And a method of driving the backlight unit described above to irradiate light onto the liquid crystal panel.

The backlight unit according to the present invention may compensate for the color difference for each region with respect to the light generated from the backlight, such that at least one of the luminance and the chromaticity is generated from the backlight.

Accordingly, since the liquid crystal display using the backlight unit of the present invention displays an image by receiving at least one of the same luminance and chromaticity from the backlight, the display quality of the image can be improved.

A backlight unit, a liquid crystal display using the same, and a driving method thereof 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 block diagram illustrating a backlight unit and a liquid crystal display using the same according to an exemplary embodiment of the present invention. 2 is a block diagram illustrating a backlight unit according to a first embodiment of the present invention.

The backlight unit 10 illustrated in FIGS. 1 and 2 compensates for a dimming value control signal input from the outside, that is, a chroma width and a luminance value input from the outside to the dimming control signal Dim, thereby modulating a pulse width. An inverter controller 14 for generating a pulse width modulation (PWM) signal, an inverter 16 for generating an AC drive signal ADS in response to a PWM signal from the inverter controller 14, and a plurality of light sources; A backlight 12 for generating light in accordance with the AC drive signal ADS is provided.

In addition, the backlight unit 10 of the present invention includes a photosensor 24 and a detector 26 to detect at least one of chromaticity and luminance values of light generated from the backlight 12 for each of a plurality of regions. And a photo detector 22 for supplying at least one of the detected chromaticity and luminance values for each region to the inverter controller 14. Here, the photo detector 22 may be a general colorimeter and luminance meter, and the photo detector 22 is attached to the outside of the backlight unit 10 to be connected to the inverter control unit 14. The photo detector 22 may be detached from the inverter controller 12 when the detection of the chromaticity and luminance values of the light generated from the backlight 12 is completed.

In the backlight unit 10a illustrated in FIG. 2, the central area CD and both outer regions of the direct type LED backlight 12a without the liquid crystal panel 2 are provided on the direct type LED backlight 12a. Detecting at least one of chromaticity and luminance values of SD1, SD2). In this case, the inverter controller 14 may include a plurality of PWMs for driving the plurality of inverters 16 and corresponding LED drivers (not shown) according to at least one of chromaticity and luminance values input from the photodetector 26. Can be generated by varying the signal. The operation and the PWM signal generation method for the backlight unit 10 will be described in more detail later with reference to the accompanying drawings.

1 illustrates a liquid crystal panel 2 including a plurality of pixels, a data driver 4 driving a plurality of data lines DL1 to DLm, and a plurality of gate lines GL1 to GLn. A timing controller 8 for aligning and supplying the gate driver 6 to be driven, the image data RGB inputted from the outside to the data driver 4, and controlling the data driver 4 and the gate driver 6; The backlight unit 10 according to the embodiment of the present invention as described above is provided.

The liquid crystal panel 2 includes a thin film transistor (TFT) formed in each pixel region defined by a plurality of gate lines GL1 to GLn and a plurality of data lines DL1 to DLm, and a liquid crystal connected to a TFT. Capacitor Clc is provided. 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 data 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 data 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 may be formed by overlapping the pixel electrode with the storage line and the insulating layer interposed therebetween.

The data driver 4 converts the digital image data Data into an analog image signal according to the data control signal DCS from the timing controller 8, and scan pulses are supplied to the respective gate lines GL1 to GLn. An analog video signal corresponding to one horizontal line is supplied to each data line DL1 through DLm every horizontal period. That is, the data driver 4 selects a gamma voltage having a predetermined level according to the gray value of the analog video signal, and supplies the selected gamma voltage to each of the data lines DL1 to DLm.

The gate driver 6 sequentially generates scan pulses, for example, gate high pulses, in response to the gate control signal GCS from the timing controller 8, and sequentially supplies them to the gate lines GL1 to GLn.

The timing controller 8 arranges the image data RGB from the outside to be suitable for driving the liquid crystal panel 2 and supplies the image data RGB to the data driver 4. In addition, the gate control signal GCS and the data control signal DCS are generated using the synchronization signals DCLK, DE, Hsync, and Vsync from the outside to control the data driver 4 and the gate driver 6. . Here, the timing controller 8 generates a dimming control signal Dim using the synchronization signals DCLK, DE, Hsync, Vsync and image data RGB from the outside, and the backlight unit 10 generates the dimming control signal Dim. Also supplied to.

The backlight 12a includes a plurality of light sources for generating light. Here, the light source may include an external electrode fluorescent lamp (EEFL), a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), and a light emitting diode (LED). Lamps) may be used. These lamps may be driven by an AC voltage from the inverter 16, that is, an AC drive signal ADS, to generate light. Hereinafter, a direct type LED backlight 12a using a plurality of red (R), green (G), and blue (B) LEDs (hereinafter, R_LED, G_LED, B_LED) shown in FIG. 2 as a light source will be described. do.

The inverter controller 14 compensates the chromaticity and luminance values input from the photo detector 22 to the dimming control signal Dim supplied from an external system or the timing controller 8, thereby providing a plurality of inverters 16 and corresponding LEDs. Generate a plurality of PWM signals for driving the driver (not shown). To this end, the inverter controller 14 varies the duty ratio of the PWM signal, that is, the high signal ratio in one period, in accordance with at least one of the chromaticity and luminance values input from the photodetector 22. Inverter control IC 18 which generates a signal, and stores the duty ratio of the PWM signal varied from the inverter control IC 18 or supplies the duty ratio of the pre-stored PWM signal to the inverter control IC 18. The memory 20 is provided.

The inverter control IC 18 of FIG. 2 sequentially orders at least one of chromaticity and luminance values of the center region CD and the outer regions SD1 and SD2 of the direct type LED backlight 12a from the photo detector 22. It is supplied repeatedly. The duty ratio of the PWM signal is equal so that at least one of the chromaticity and luminance values of both outer regions SD1 and SD2 is equal to each other based on at least one of chromaticity and luminance values of the central region CD. Repeatedly adjust and set. Thereafter, the duty ratio of the set PWM signal is supplied to the memory 20 including a plurality of look-up tables. As the inverter control IC 18, an IC such as BD9766FV or BD9897FV may be used.

Specifically, in the direct type LED backlight 12a, since a plurality of R_LEDs, G_LEDs, and B_LEDs are sequentially arranged, the color of red (R) arranged in a line is large in the outer area SD1 of one side. In addition, in the outer area SD2 on the other side, the color of blue B arranged in a line is large. Therefore, the inverter control IC 18 performs each PWM so that at least one of the chromaticity and luminance values of the center region CD and the outer regions SD1 and SD2 sequentially sequentially input from the photodetector 22 are the same. Adjust the duty ratio of the signal repeatedly. The duty ratio at the time when at least one of the chromaticity and luminance values of the central region CD and the outer regions SD1 and SD2 are equal to each other is transmitted to the memory 20 and stored. After that, when the photo detector 22 is detached and the backlight unit 10a is configured and driven in the liquid crystal display device, the inverter control IC 18 receives a plurality of values according to the duty ratio stored in the memory 20. Generates a PWM signal and supplies it to each inverter 16 and the LED driver corresponding thereto.

Each inverter 16 and the corresponding LED driver generates an AC driving signal ADS in response to each PWM signal input from the inverter control IC 18, and drives the plurality of R_LEDs, G_LEDs, and B_LEDs. Supply to each LED module (not shown) for. In other words, each inverter 16 adjusts the supply time, amplitude, pulse width, and the like of the AC drive signal ADS supplied to each LED module so as to correspond to each PWM signal input thereto. At least one LED module may be connected to each inverter 16 and the corresponding LED driver, and the number of LED modules connected to each inverter 16 is determined in consideration of a voltage drop near the LED module. . Each LED module may be provided with an LED block, a switching circuit, and the like, each of which includes a plurality of R_LEDs, G_LEDs, and B_LEDs connected in series or in parallel. The inverter 16 may generate an AC driving signal ADS by compensating for the feedback voltage or the current FI from the backlight 12a.

3 is another configuration diagram illustrating a backlight unit according to a first embodiment of the present invention.

In the backlight unit 10b illustrated in FIG. 3, the center region CD and both outer regions of the edge-type LED backlight 12b are not provided with the liquid crystal panel 2 on the edge-type LED backlight 12b. Detecting at least one of chromaticity and luminance values of SD1, SD2). In this case, the inverter controller 14 may vary the plurality of PWM signals for driving the plurality of inverters 16 and LED drivers corresponding thereto according to at least one of chromaticity and luminance values input from the photo detector 22. Will be created.

Inverter control IC 18 of FIG. 3 includes at least one of chromaticity and luminance values of the center region CD and the outer regions SD1 and SD2 of the edge-type LED backlight 12b from the photo detector 22. Receive sequentially and repeatedly. The duty ratio of the PWM signal is equal so that at least one of the chromaticity and luminance values of both outer regions SD1 and SD2 is equal to each other based on at least one of chromaticity and luminance values of the central region CD. Repeatedly adjust and set. Thereafter, the duty ratio of the set PWM signal is supplied to the memory 20 including a plurality of look-up tables.

Specifically, the edge-type LED backlight 12b has a plurality of R_LEDs, G_LEDs, and B_LEDs sequentially arranged at the edge portion of the backlight 12b, so that the outer region SD1 of one side has R_LEDs formed on the outermost side. The color of red R becomes large. In addition, in the outer region SD2 on the other side, the color of blue B is large due to the B_LEDs formed at the outermost portion. Therefore, the inverter control IC 18 performs each PWM signal so that at least one of the chromaticity and luminance values of the center region CD and the outer regions SD1 and SD2 which are sequentially repeatedly input from the photo detector 22 are equal. Repeatedly adjust the duty ratio of. The duty ratio at the time when at least one of the chromaticity and luminance values of the central region CD and the outer regions SD1 and SD2 are equal to each other is transmitted to the memory 20 and stored. Subsequently, when the photo detector 22 is detached and the backlight unit 10b is formed and driven in the liquid crystal display device or the like, the inverter control IC 18 stores the plurality of inverters according to the duty ratio stored in the memory 20. Generates a PWM signal and supplies it to each inverter 16 and the LED driver corresponding thereto.

4 is a configuration diagram illustrating a backlight unit according to a second embodiment of the present invention.

The backlight unit 10c shown in FIG. 4 has a value of chromaticity UV and luminance Y input from the backlight 12c to the dimming control signal Dim input from the timing controller 8 or an external system. An inverter controller 14 for compensating at least one value to generate a PWM signal, an inverter 16 for generating an AC drive signal ADS in response to the PWM signal from the inverter controller 14, and a plurality of light sources The light 12 generates light according to the AC drive signal ADS, and detects at least one of chromaticity (UV) and luminance (Y) values of the generated light and supplies the backlight 12 to the inverter controller 14. Equipped.

The backlight unit 10c has chromaticity and luminance of the center region and both outer regions of the edge-type LED backlight 12c with or without the liquid crystal panel 2 on the edge-type LED backlight 12c. Detecting at least one of the values. In this case, the inverter controller 14 may include a plurality of inverters 16 and corresponding LED drivers (not shown) according to at least one of chromaticity (UV) and luminance (Y) values input from the edge type LED backlight 12c. ) To generate a plurality of PWM signals for driving.

The edge type LED backlight 12c further includes at least one sensor module PS_Dm so as to face at least one LED module LED_Dm. In detail, the edge type LED backlight 12c includes a sensor module PS_Dm provided with a plurality of photosensors PS1 to PSn at positions facing corresponding to the LED modules LED_Dm in which a plurality of R_LEDs, G_LEDs, and B_LEDs are arranged. ) Is formed. The sensor module PS_Dm supplies at least one of chromaticity UV and luminance Y values detected from the plurality of photosensors PS1 to PSn to the inverter controller 14.

The inverter control IC 18 of FIG. 4 is repeatedly supplied with at least one of chromaticity UV and luminance Y values detected from the plurality of photosensors PS1 to PSn. In addition, at least one of chromaticity or luminance values from the photosensors located in the center region, for example, the fourth to n-3 photosensors PS4 to PSn-3, may be the first to the first region located in the outer region. The duty ratio of the PWM signal is repeatedly set to be equal to at least one of chromaticity or luminance values from the third photoelectric sensors PS1 to PS3 and the nth to nth to nth photosensors PSn-2 to PSn. Adjust and set with. Thereafter, the duty ratio of the set PWM signal is supplied to the memory 20 including a plurality of look-up tables and the like, and the generated PWM signal is supplied to the inverter 16.

Specifically, since the edge type LED backlight 12c of FIG. 4 has a plurality of R_LEDs, G_LEDs, and B_LEDs sequentially arranged at the edge portion of the backlight 12c, the edge type LED backlight 12c of the edge type LED backlight 12c is red due to one outermost R_LED. The color of (R) becomes large. In addition, in the outer region of the other side, the color of blue (B) is large due to the B_LED of the outermost side of the other side. Accordingly, the inverter control IC 18 receives at least one value of chromaticity and luminance values repeatedly detected from the plurality of photosensors PS1 to PSn, and receives chromaticity and luminance values input from the plurality of photosensors PS1 to PSn. The duty ratio of each PWM signal is repeatedly adjusted so that at least one of the values is the same.

For example, the inverter control IC 18 may include a first average value of at least one of chromaticity and luminance values detected from the fourth to n-3th photosensors PS4 to PSn-3 in the outer region. Duty of the PWM signal to be equal to an average value of at least one of chromaticity and luminance values detected from the third to third photo sensors PS1 to PS3 and the n-2 to n th photo sensors PSn-2 to PSn. You can adjust and set the ratio repeatedly. In addition, the inverter control IC 18 may include the first photo sensor PS1 and the n th photo in which the average value of the luminance detected from the second through n-th photo sensors PS2 through PSn-2 is located in the outermost region, respectively. The duty ratio of the PWM signal may be repeatedly adjusted and set to be the same as the luminance value detected by the sensor PSn.

Each inverter 16 and its corresponding LED driver generate an AC drive signal ADS so as to correspond to each PWM signal input from the inverter control IC 18, and the AC drive signal generated in the LED module LED_Dm ( ADS) to drive each R_LED, G_LED, and B_LED. In other words, each inverter 16 and its corresponding LED driver determine the supply time, amplitude or pulse width of the AC driving signal ADS supplied to each LED module LED_Dm so as to correspond to each PWM signal input thereto. Adjust the output. In addition, the inverter 16 may generate the AC driving signal ADS by compensating the feedback voltage or the current FI from the backlight 12c.

FIG. 5 is a flowchart illustrating a method of driving the backlight unit shown in FIG. 4.

The driving method of the backlight unit 10c according to the second embodiment of the present invention will be described in more detail with reference to FIG. 5.

First, the inverter control IC 18 of the present invention generates a PWM signal in accordance with the dimming control signal Dim from the external system or the timing controller 8 and supplies it to the inverter 16. Then, each inverter 16 and the corresponding LED driver generates an AC drive signal ADS so as to correspond to the PWM signal and supplies it to the LED module LED_Dm of the backlight 12c so as to provide a plurality of R_LED, G_LED, and B_LED. Will be driven (ST1).

Thereafter, when each of the R, G, and B_LEDs is driven, the sensor module PS_Dm equipped with the plurality of photosensors PS1 to PSn is configured to detect the chromaticity UV and luminance (D) detected from the photosensors PS1 to PSn. Y) The value is repeatedly supplied to the inverter control IC 18. (ST2)

The inverter control IC 18 receives at least one of chromaticity (UV) and luminance (Y) values detected from each of the photoelectric sensors PS1 to PSn through the sensor module PS_Dm, thereby receiving each photoelectric sensor PS1 to PSn. It is determined whether at least one of the chromaticity (UV) and luminance (Y) values input from the same value is the same (ST3).

Specifically, the inverter control IC 18, when at least one of the chromaticity (UV) and the luminance (Y) value input from each of the photosensors PS1 to PSn is not the same, each photosensor (PS1 to PSn). The duty ratio of each PWM signal is repeatedly adjusted so that at least one of the chromaticity (UV) and luminance (Y) values input from the same value is the same.

Meanwhile, the inverter control IC 18 may include the first photosensor PS1 and the first photosensor having the average value of the luminance detected from the second to n-1 photosensors PS2 to PSn-2 respectively positioned in the outermost region. The duty ratio of the PWM signal may be repeatedly adjusted to be equal to the luminance value detected by the n photosensor PSn.

As described above, the inverter control IC 18 stores the PWM signal duty ratio at this time when at least one of the chromaticity UV and luminance Y values input from the photosensors PS1 to PSn are the same. Supply it to (20) and store it. (ST4)

Then, each inverter 16 and the corresponding LED driver generates an AC drive signal ADS to correspond to the PWM signal generated from the inverter control IC 18 according to the duty ratio stored in the memory 20. In addition, the AC driving signal ADS generated to the LED module LED_Dm is supplied to drive each of the R_LED, the G_LED, and the B_LED.

As described above, the backlight unit 10 according to the first and second exemplary embodiments of the present invention compensates for the color difference for each region of the light generated from the backlight 12 to compensate for the luminance of the light generated in each region. And chromaticity can be the same. Accordingly, since the liquid crystal display using the backlight unit 10 of the present invention displays the image by receiving at least one of the same luminance and chromaticity from the backlight 12, the display quality of the image may be improved. .

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and 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 block diagram showing a backlight unit and a liquid crystal display using the same according to an embodiment of the present invention.

2 is a block diagram showing a backlight unit according to a first embodiment of the present invention.

3 is another configuration diagram illustrating a backlight unit according to a first embodiment of the present invention;

4 is a block diagram showing a backlight unit according to a second embodiment of the present invention.

5 is a flowchart illustrating a method of driving the backlight unit shown in FIG. 4.

* 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: back light unit 12: back light

14: inverter control unit 16: inverter

18: inverter control IC 20: memory

22: photo detector 24: photo sensor

26: detection unit PWM signal: pulse width modulation signal

ADS: AC Drive Signal PS_Dm: Photo Sensor Module

PS1 to PSn: first to nth photosensors

R, G, B_LED: Red, Green, and Blue Light Emitting Devices

Claims (10)

An inverter controller configured to compensate for at least one of chromaticity and luminance values from the outside with a dimming control signal from the outside to generate a PWM signal; An inverter generating an AC driving signal in response to the PWM signal; And Back light is provided with a plurality of light sources to generate light according to the AC drive signal, and to detect at least one of the chromaticity and luminance value of the generated light to supply to the inverter control unit Light unit. The method of claim 1, The back light At least one LED module in which a plurality of R, G, B_LEDs are sequentially arranged; and At least one sensor module, wherein a plurality of photosensors are formed to face each of the R, G, and B_LEDs to supply at least one of the chromaticity and luminance values detected from each of the plurality of photosensors to the inverter controller. Back light unit comprising a. The method of claim 2, The inverter controller Based on at least one of chromaticity and luminance values detected by the photosensors formed in the central region of the backlight, at least one of chromaticity and luminance values detected by the photosensors formed in the outer region of the backlight is determined. An inverter control IC that repeatedly adjusts and sets the duty ratio of the PWM signal to be the same, and And a memory for storing the duty ratio of the set PWM signal and supplying the duty ratio of the set PWM signal to the inverter control IC. The method of claim 1, Detecting at least one of chromaticity and luminance values of the light generated from the backlight in the order of the center region and both outer regions of the backlight, and sequentially detecting at least one of the detected chromaticity and luminance values, respectively. And a photo detector for supplying the inverter control unit. The method of claim 4, wherein The inverter controller An inverter control IC which repeatedly adjusts and sets the duty ratio of the PWM signal such that at least one of each of the chromaticity and luminance values detected in the respective areas is the same, and And a memory for storing the duty ratio of the set PWM signal and supplying the duty ratio of the set PWM signal to the inverter control IC. A liquid crystal panel formed with a plurality of pixels; A gate and data driver driving the plurality of pixels; A timing controller for supplying image data input from the outside to the gate and data driver and controlling the gate and data driver; And A backlight unit according to any one of claims 1 to 5, for irradiating light to the liquid crystal panel. Generating a PWM signal by compensating at least one of chromaticity and luminance values from the outside with the dimming control signal from the outside; Generating an AC driving signal in response to the PWM signal; And Generating light according to the AC drive signal, and detecting and outputting at least one of chromaticity and luminance values of the generated light. The method of claim 7, wherein The PWM signal generation step Detecting at least one of chromaticity and luminance values of light generated from the backlight by a plurality of regions through a plurality of photosensors formed in the backlight; And The duty ratio of the PWM signal is repeatedly adjusted so that at least one of the chromaticity and luminance values detected in the outer region is the same based on at least one of the chromaticity and luminance values detected in the center region among the plurality of regions. And setting the backlight unit. The method of claim 7, wherein The PWM signal generation step Repeatedly detecting at least one of chromaticity and luminance values of light generated from the backlight using a photo detector in the order of the center region and the outer region of the backlight, respectively; And repeatedly adjusting and setting a duty ratio of the PWM signal so that at least one of each of chromaticity and luminance values detected in the respective areas is equal to each other. In the method of driving a liquid crystal display device having a liquid crystal panel having a plurality of pixels and a backlight unit for irradiating light to the liquid crystal panel, Adjusting the transmittance of light to display an image; And 10. A method of driving a liquid crystal display device comprising the driving method of any one of claims 7 to 9 for irradiating light to the liquid crystal panel.

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