KR20080074682A - Light generating device, display device having same and driving method thereof - Google Patents

Abstract

A light generating device, a display device having the same and a driving method thereof are provided to compensate uniformity of white light in real time, thereby providing more improved white light uniformity. A light generating device(100) comprises a luminance detector(110), a dimming signal controller(120), a light source driver(130), a light source unit(140) and a light source corrector(150). The luminance detector receives plural image data from the outside, and detects and outputs plural luminance data corresponding to the plural image data. The luminance detector compares plural gradations, corresponding to the plural image data, with a reference gradation and outputs an enable signal based on the comparison result. The light source corrector starts driving in response to the enable signal, receives white light emitted from a light source, and outputs a correction signal so as to correct light characteristics of the white light.

Description

LIGHT GENERATION DEVICE, DISPLAY DEVICE HAVING AND DRIVING METHOD THEREOF}

In order to more fully understand the drawings used in the detailed description of the invention, a brief description of each drawing is provided.

1 is a block diagram showing the configuration of a light generating device according to the present invention.

FIG. 2 is a diagram illustrating a configuration of the luminance detector shown in FIG. 1.

3 is a diagram illustrating a configuration of a light source correcting unit illustrated in FIG. 1.

4 is a diagram illustrating a configuration of the color temperature correction unit illustrated in FIG. 3.

5 is a block diagram of a display device employing the light generating device shown in FIG. 1.

6 is a flowchart illustrating a method of driving the light generator shown in FIGS. 1 and 5.

The present invention relates to a light generating device, a display device having the same, and a driving method thereof, and more particularly, to a light generating device for uniformly adjusting the light uniformity, a display device having the same, and a driving method thereof.

In general, as a backlight unit for providing light to a display panel, a cold cathode fluorescent lamp (CCFL) and a light emitting diode (LED) are widely used. It is becoming.

LEDs have many advantages over CCFLs. For example, in constructing a backlight unit, LEDs are less size constrained than CCFLs. In addition, the LEDs are easy to adjust individual brightness. In addition, CCFLs have a dimming range of 25% to 100%, while LEDs theoretically have a dimming range of 0% to 100%. Because of these many advantages, the use of LEDs as a backlight unit is increasing.

Meanwhile, in order to provide more improved display quality, a display device equipped with LEDs uses various types of LED driving methods. Currently used LED driving methods include scanning impulsive (Scanning-Impulsive), sequential scanning (Sequential Scanning), divided driving method (Localized Dimming). In particular, the local dimming method may overcome the constraint of contrast ratio (CR) generated by using a backlight unit that emits light having a constant brightness.

By the way, the LED has an optical characteristic, such as color coordinates (or color temperature) and luminance is emitted as the time and temperature changes. These device characteristics lower the white light uniformity (also called "white color balancing") emitted from the LED. Therefore, the backlight unit employing the LED should properly compensate for the uniformity of the white light. Here, the "uniformity of white light" refers to the degree of indicating how evenly white is displayed when the full white pattern is displayed on the entire display screen.

Recently, in order to compensate for uniformity of white light, a color feedback system (hereinafter referred to as 'CFS') using an optical sensor has been developed.

Briefly, this CFS senses the amount of light emitted from the entire LED through an optical sensor mounted inside the backlight unit, and converts the detected amount of light into a voltage signal. The CFS compares the converted voltage signal with the reference signal and outputs a control signal based on the comparison result. The LED driving circuit adjusts the driving current supplied to the LED in response to the control signal. The LED emits the target light in response to the regulated driving current.

By the way, this CFS is very difficult to apply to the LED backlight driven by the split drive method. Because, the LED backlight unit of the local dimming method for individually adjusting the brightness of the divided region should be provided with a sensor for each divided region. Therefore, a large cost is required. In addition, the LED driving unit of the split driving method should block the light interference from the adjacent area of the area to be detected by the sensor. Therefore, there is a technical difficulty in applying the CFS in the backlight unit of the split driving method.

Accordingly, an object of the present invention is to provide a light generating device capable of compensating light uniformity in real time.

Another object of the present invention is to provide a display device including the light generating device.

Still another object of the present invention is to provide a method of driving the light generating device.

According to an aspect of the present invention, there is provided a light generating apparatus including a luminance detector, a dimming signal controller, a light source driver, a light source unit, and a light source correction unit.

The luminance detection unit receives a plurality of image data from outside, detects and outputs a plurality of luminance data corresponding to the plurality of image data, compares the plurality of gray levels corresponding to the plurality of image data with a reference gray scale, An enable signal is output based on the comparison result.

The dimming signal controller receives a correction signal and the luminance data, and outputs a first dimming signal corresponding to the luminance data and a second dimming signal correcting the first dimming signal based on the correction signal.

The light source driver outputs a driving signal in response to any one of the first and second dimming signals from the dimming signal controller.

The light source unit includes a plurality of light source units generating white light in response to the driving signal.

The light source corrector starts driving in response to the enable signal, and receives the white light emitted from the light source unit and outputs the correction signal to correct an optical characteristic of the white light.

 In addition, the display device according to another aspect of the present invention for achieving the above technical problem includes a display unit and a light generating device. The display unit displays an image corresponding to image data provided from the outside using white light.

The light generating device is formed under the display unit to generate the white light. The light generating device included in the display device of the present invention has the same components and functions as the above-described light generating device. Therefore, detailed description thereof will be omitted.

According to another aspect of the present invention, there is provided a method of driving a light generating apparatus, which receives a plurality of image data. Luminance data is extracted from the image data, and the gray level of the video data is compared with a preset gray level. A dimming signal of any one of a first dimming signal corresponding to the luminance data and a second dimming signal corrected by the first dimming signal is output based on the comparison result. A driving signal corresponding to the output dimming signal is generated, and white light corresponding to the driving signal is emitted.

According to the light generating device, the display device having the same, and the driving method thereof according to the present invention, a correction operation for compensating for uniformity of white light is performed whenever image data having a predetermined reference gray level or more is input.

Accordingly, the light generating device of the present invention compensates the uniformity of white light in real time to provide more improved white light uniformity. Furthermore, the display device of the present invention employing the light generating device provides improved display quality.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

In understanding the drawings, it should be noted that like parts are intended to be represented by the same reference numerals as much as possible. In addition, in the following description, numerous specific details, such as specific process flows, are described to provide a more general understanding of the invention. And detailed description of known functions and configurations that are determined to unnecessarily obscure the subject matter of the present invention is omitted.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing the configuration of a light generating apparatus 100 according to the present invention.

Referring to FIG. 1, the light generating apparatus 100 according to the present invention outputs a luminance detector 110 that detects luminance data LS from image data DS, and a dimming signal corresponding to the luminance data LS. The dimming signal controller 120, a light source driver 130 for outputting a drive signal corresponding to the dimming signal, a light source unit 140 for emitting white light in response to the drive signal and correcting the optical characteristics of the emitted white light It includes a light source correction unit 150. In addition, the light generating apparatus 100 according to the present invention further includes a frame memory 105. The frame memory 105 stores input image data DS in units of frames. The stored image data DS is output to the luminance detector 110.

FIG. 2 is a diagram illustrating a configuration of the luminance detector 110 illustrated in FIG. 1.

2, the luminance detector 110 includes a luminance data extractor 112 and an image analyzer 114.

The luminance data extractor 112 receives a plurality of image data DSs corresponding to one frame through the frame memory 105, and receives a plurality of luminance data LS from each of the plurality of image data DSs. Is detected and output.

Each image data DS is digital data including image information, and includes red (R) data, green (G) data, and blue (B) data. Therefore, the luminance data LS detected from each image data DS includes red luminance data rLS, green luminance data gLS, and blue luminance data bLS.

In this embodiment, a light source consisting of three color (e.g., red, green and blue) LED light emitting diodes is used. Therefore, the red luminance data rLS is used to adjust the light amount of the red light emitting diode, and the green luminance data gLS is used to adjust the light amount of the green light emitting diode. The blue luminance data bLS is used to adjust the amount of light of the blue light emitting diode. The amount of light of the red, green, and blue light emitting diodes is mixed to form white light. Of course, a light source consisting of a monochromatic (white) LED light emitting diode may be used.

On the other hand, the image data DS does not include luminance data. Accordingly, the luminance data extracting unit 112 converts the image data DS to color space data through a widely known color space conversion algorithm, and converts the image data from the color space data. Luminance data LS corresponding to (DS) is extracted.

The image analyzer 114 extracts a plurality of gray levels from each image data DS, and compares the extracted plurality of gray levels with a predetermined reference gray level. The image analyzer 114 outputs an enable signal EN when all of the plurality of gray levels are equal to or greater than the predetermined reference gray level. The preset reference gradation may be variously set by the system designer, and preferably is set to 1/2 of the entire gradation interval. For example, if the total gradation is 256 gradations, the reference gradation is set to 127 gradations.

Referring back to FIG. 1, the dimming signal controller 120 receives the luminance data LS from the luminance detector 110 and the correction signal CS from the light source corrector 150. The dimming signal controller 120 outputs any one of the first dimming signal DIM1 corresponding to the luminance data LS and the second dimming signal DIM2 correcting the first dimming signal.

The first dimming signal DIM1 corresponds to a first red dimming signal corresponding to the red luminance data rLS, a first blue dimming signal corresponding to the blue luminance data bLS, and the green luminance data gLS. And a first green dimming signal. The second dimming signal may include a second red dimming signal correcting the first red dimming signal, a second green dimming signal correcting the first green dimming signal, and a second blue dimming signal correcting the first blue dimming signal. It includes a dimming signal.

For reference, the dimming signal is a pulse type signal generated to adjust the luminance of the white light emitted from the light source when trying to increase the contrast ratio (C / R) of the power saving mode or the display screen.

The dimming signal controller 120 adjusts the duty ratio of the dimming signals DIM1 and DIM2 to adjust the luminance of the white light of the light source. Here, the duty ratio refers to the ratio of the high section to one period of the pulse. This method is called pulse width modulation (PWM). The luminance of the white light increases as the ratio occupied by the high section increases.

The duty ratio is preset according to the gray level of the input image data. For example, if the total gradation is 256 gradations, the duty ratio is set in each gradation unit. Accordingly, the dimming signal controller 120 outputs a dimming signal having a minimum duty ratio when luminance data corresponding to zero gray scale is input, and outputs a dimming signal having a maximum duty ratio when luminance data corresponding to 256 gray scale is input. Output

In the embodiment of the present invention, the duty ratio is not set for each of the grayscales. That is, the duty ratio is set only for the previous gradation interval of the preset reference gradation among all the gradation intervals, and is set to have the maximum duty ratio in all remaining gradation intervals. Therefore, the white light emitted from the light source unit 140 is maintained at only the maximum luminance without adjusting the brightness in the entire gray scale interval above the preset reference gray scale.

Subsequently, the light source driver 130 generates and outputs a driving voltage Vd corresponding to any one of the first and second dimming signals DIM1 and DIM2 provided from the dimming signal controller 120. do. The driving voltage Vd includes a red driving voltage, a green driving voltage, and a blue driving voltage.

The light source unit 140 includes the plurality of light sources that generate white light in response to the driving voltage Vd. Each of the plurality of light sources includes red, blue, and green light emitting diodes (hereinafter, referred to as LEDs). The red, green, and blue LEDs receive the red driving voltage, the green driving voltage, and the blue driving voltage, respectively, and emit their respective color lights (red light, green light, and blue light). These emitted color lights are mixed according to their respective light amounts to emit white light. Here, the plurality of light sources are partitioned into a plurality of groups, and the light sources provided in the blocks drive independently of the light sources provided in the adjacent blocks.

The light source corrector 150 starts driving in response to the enable signal EN from the image analyzer 110. The light source correcting unit 150 receives the white light emitted from the light source unit 140 and outputs the correction signal CS to correct the optical characteristics of the white light.

3 is a block diagram illustrating a configuration of the light source correcting unit 150 shown in FIG. 1.

Referring to FIG. 3, the light source compensator 150 includes a light detector 152, a light detector 154, a first compensator 156, and a second compensator 158. The light detector 152 includes at least one optical sensor for detecting the amount of white light output from the plurality of light sources.

The light detector 152 converts the red light, the green light, and the blue light constituting the detected white light into current values Ri, Gi, and Bi, respectively, and outputs them.

The photodetector 154 converts the current values Ri, Gi, and Bi into voltage values of Rv, Gv, and Bv, respectively, and outputs them. This is because the voltage values Rv, Gv, and Bv are easier to adjust than the current values Ri, Gi, and Bi. Hereinafter, the voltage values Rv, Gv, and Bv are referred to as light detection signals.

The first correction unit 156 receives the light detection signals Rv, Gv, and Bv, compares and calculates the luminance values corresponding to the light detection signals Rv, Gv, and Bv with previously stored target brightness values. Based on the result of the comparison operation, first correction data Rv1, Gv1, and Bv1 are output.

The first corrector 156 includes a first memory 156a and a luminance corrector 156b. The first memory unit 156a stores the target luminance value in the form of a lookup table. The luminance corrector 156b compares and calculates a difference value between the stored target luminance value and a luminance value corresponding to the light detection signals Rv, Gv, and Bv, and based on the comparison operation, the first correction value is corrected. Data CS1: Rv2, Gv2, Bv2 is output. The output first correction data CS1 is applied to the dimming signal controller 120.

The second corrector 158 receives the light detection signals Rv, Gv, and Bv, and compares and computes the color temperature values corresponding to the light detection signals Rv, Gv, and Bv with previously stored target color temperature values. Based on the result of the comparison operation, second correction data CS2 (Rv2, Gv2, Bv2) is output.

In detail, the second correction unit 158 includes a second memory unit 158a and a color temperature correction unit 158b. The second memory unit 158a stores the target color temperature value in the form of a lookup table. In addition, the second memory unit 158a may store the target color temperature value in the form of a lookup table and a target X coordinate value and a target Y coordinate value corresponding to the CIE coordinate system.

The color temperature correction unit 158b reads the stored target color temperature value, compares and calculates a difference value between the read target color temperature value and the color temperature value corresponding to the light detection signals Rv, Gv, and Bv, The second correction data CS2 (Rv2, Gv2, Bv2) is output based on the difference value.

FIG. 4 is a block diagram showing the configuration of the color temperature correction unit 158b shown in FIG.

Referring to FIG. 4, the color temperature corrector 158b includes an XYZ converter 158b1, a chromaticity calculator 158b2, a coordinate corrector 158b3, and a color temperature converter 158b4.

The XYZ converter 158b1 receives the light detection signals Rv, Gv, and Bv, and converts the light detection signals Rv, Gv, and Bv into XYZ values of the CIE coordinate system.

The chromaticity calculator 158b2 calculates a raw X coordinate X according to a distribution of the converted XYZ value in a color temperature value corresponding to a white region of the CIE coordinate system, and based on the calculated raw X coordinate X. The raw Y coordinate (Y) is calculated.

The coordinate corrector 158b3 reads the target X coordinate X 'and the target Y coordinate Y' of the CIE coordinate system corresponding to the target color temperature value stored in the second memory unit 158a, thereby reading the target X coordinate ( X '), the target Y coordinate Y' and the raw X coordinate X and the raw Y coordinate Y inputted from the chromaticity calculator 158a-2 are compared and calculated. According to the comparison operation result, the coordinate correcting unit 158a-3 outputs a corrected X coordinate X ″ and a corrected Y coordinate Y ″.

Specifically, the coordinate correcting unit 158b3 includes an X coordinate difference value between the raw X coordinate X and the target X coordinate X 'and a Y coordinate difference between the raw Y coordinate Y and the target Y coordinate Y'. The values are respectively calculated, and the corrected X coordinate (X ") and corrected Y coordinate (Y") are output based on the X coordinate difference value and the Y coordinate difference value, respectively.

The color temperature converter 158b4 calculates a corrected color temperature value corresponding to the light detection signals Rv, Gv, and Bv based on the corrected X coordinate X ″ and the corrected Y coordinate Y ″. Second correction data CS2 (Rv2, Gv2, Bv2) corresponding to the calculated corrected color temperature value is output. The output second correction data CS2 is applied to the dimming signal controller 120.

The dimming signal controller 120 receives the luminance data LS from the luminance detector 110 based on the correction signal CS from the light source compensator 150 and the first dimming signal DIM1. A second dimming signal DIM2 is generated by correcting the first dimming signal DIM1 and output. The dimming signal controller 120 further includes a memory capable of storing the first and second correction data CS1 and CS2, and controls the first and second correction data CS1 and CS2 to control the dimming signal. It is stored in the memory as necessary reference data.

5 is a block diagram of a display device employing the light generating device 100 shown in FIG. 1. Here, among the components shown in FIG. 5, the same reference numerals are given to the elements illustrated in FIG. 1, and a detailed description thereof will be briefly described.

Referring to FIG. 5, the display device 1000 includes a display unit 200 and a light generating device 100.

The display unit 200 includes a liquid crystal display panel 210, a gray voltage generator 220, a data driver 230, a gate driver 240, and a signal controller 250.

The liquid crystal display panel 210 displays an image in response to the second data signals D1,..., And Dm corresponding to the first data signals R, G, and B provided from the signal controller 250.

The liquid crystal display panel 210 may include first to mth lines crossing first to nth gate lines GL1 to GLn and first to nth gate lines GL1 to GLn. Data lines DL1, ..., DLm. 2 adjacent to two adjacent gate lines of the first to nth gate lines GL1 to GLn and the first to mth data lines DL1 to DLm on the liquid crystal display panel. The pixel area PA is defined by two data lines.

The thin film transistor 216 and the liquid crystal capacitor connected to the first to n th gate lines GL1 to GLn and the first to m th data lines DL1 to DLm in the pixel area PA. 218 is formed.

The gray voltage generator 220 generates a plurality of gray voltages corresponding to an image signal input from the outside, and provides the gray voltages to the data driver 230.

The data driver 230 is a second data signal that is a gray voltage corresponding to the first data signals R, G, and B stored among the plurality of gray voltages input from the gray voltage generator 220, that is, an analog voltage value. Produces (D1, ..., Dm) Subsequently, the data driver 230 transmits the second data signals D1,..., And Dm to the first to m th data lines DL1,..., DLm in response to a first timing signal T1. )

The gate driver 240 sequentially applies the gate driving signals G1, ..., Gn to the first to nth gate lines GL1, ..., GLn in response to the second timing signal T2. Output Each pixel area PA of the liquid crystal display panel 210 includes a thin film transistor 216 that serves as a switching function. The thin film transistor 216 is turned on or off by the gate driving signals G1,..., Gn. By the switching operation of the thin film transistor 216, the second data signals D1,..., Dm are transmitted to the corresponding liquid crystal capacitor 218.

The signal controller 250 may include a first data signal R, G and B, a first timing signal T1 and a second timing signal T2 in response to the image signal DS in the form of a digital signal provided from the outside. ) The first data signals R, G and B are R, G and B signals in the form of digital signals. In addition, the signal controller 250 includes a frame memory, and stores the generated first data signals R, G, and B in the frame memory in one frame unit. The stored first data signals R, G, and B are input to the luminance detector 110.

The first timing signal T1 is an output instruction signal TP and a second data signal D1, which command to apply the second data signal D1,..., Dm to the liquid crystal display panel 210. ..., And a line inversion signal RVS for inverting the polarity of the data voltage corresponding to Dm).

The second timing signal T2 is a gate clock signal Gate for setting a period of the gate driving signals G1, ..., Gn applied to the first to nth gate lines GL1, ..., GLn. clock, a vertical synchronization start signal (STV) for instructing the start of the gate driving signals (G1, ..., Gn), and an output enable signal (OE) for enabling the output of the gate driver 240; Out Enable).

In FIG. 5, the luminance detector 110 receives the image data DS directly through the frame memory 105, but may receive the image data DS through the signal controller 250. have. In this case, the frame memory 105 illustrated in FIG. 5 may be replaced with a frame memory provided in the signal controller 250 itself.

In addition, in the present exemplary embodiment, although the luminance detector 110 is designed to be separated from the signal controller 250, the signal detector 250 may be provided inside the signal controller 250.

FIG. 6 is a flowchart illustrating a method of driving the light generator 100 shown in FIGS. 1 and 5.

Referring to FIG. 6, a plurality of image data are received from the outside (S610).

A plurality of luminance data is extracted from the plurality of received image data, and a plurality of gray levels corresponding to the plurality of image data are extracted to analyze image patterns of the plurality of received image data (S620).

Subsequently, an image pattern of the plurality of image data is analyzed by comparing the extracted plurality of gray levels with a preset reference gray level. In detail, when all of the extracted plurality of grayscales are larger than the reference grayscale, the image pattern is determined as a full white pattern (S630). On the other hand, if at least one of the extracted plurality of grayscales is smaller than the reference grayscale, the received image pattern is not a full white pattern.

 Subsequently, when the received image pattern is not a full white pattern, a first dimming signal DIM1 corresponding to the extracted luminance data is output (S640), and when the received image pattern is a full white pattern, the The first dimming signal corresponding to the extracted luminance data is corrected and output as the second dimming signal DIM2 (S650).

A driving voltage corresponding to any one of the output first and second dimming signals is generated (S660). White light corresponding to the generated driving voltage is generated (S670).

As described above, according to the light generating device, the display device having the same, and a control method thereof, the light generating device compensates for the uniformity of white light whenever image data of a reference gray level or more is input through the brightness detector. Perform the calibration operation.

As such, the light generating apparatus according to the present invention compensates the uniformity of the white light in real time to provide more improved white light uniformity.

In addition, the display device of the present invention employing the light generating device provides improved display quality.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (19)

Receives a plurality of video data from outside, detects and outputs a plurality of luminance data corresponding to the plurality of video data, compares the plurality of grayscales corresponding to the plurality of video data with a reference grayscale, A luminance detector for outputting an enable signal based on the result; A dimming signal controller configured to receive a correction signal and the plurality of luminance data, and output a first dimming signal corresponding to the luminance data and a second dimming signal correcting the first dimming signal based on the correction signal; A light source driver configured to output a driving signal in response to any one of the first and second dimming signals from the dimming signal controller; A light source unit including a plurality of light sources generating white light in response to the driving signal; And And a light source compensator which starts driving in response to the enable signal and outputs the correction signal to receive the white light emitted from the light source and to correct the optical characteristic of the white light. The method of claim 1, And a frame memory configured to store image data corresponding to the at least one frame and to provide the stored image data to the luminance detector. The method of claim 1, And a light characteristic of the white light is a luminance value. The method of claim 1, The optical characteristic of the white light is any one of color coordinates or color temperature. The method of claim 1, The reference gray scale is a light generating device, characterized in that the gray level corresponding to 1/2 of the entire gray scale interval. The method of claim 5, wherein And the dimming signal controller outputs a dimming signal having a preset maximum duty ratio if the plurality of image data are all equal to or greater than the reference gray level. The method of claim 1, The brightness detector, An image analyzer configured to receive the plurality of image data and to generate and output the enable signal when a plurality of gray levels corresponding to the plurality of image data are all higher than a reference gray level; And And a luminance data extraction unit for extracting a plurality of luminance data from each of the plurality of image data. The light generating apparatus of claim 1, wherein each of the plurality of light sources comprises red, green, and blue light emitting diodes. The method of claim 1, wherein the correction signal comprises first and second correction data, The light source correction unit, A light detector for detecting a light amount of the white light; A light detector for outputting a light detection signal corresponding to the detected amount of light; A first correction unit which receives the light detection signal and compares the brightness value of the light detection signal with a previously stored target brightness value and outputs the first correction data based on the result of the comparison operation; And And a second correction unit configured to receive the light detection signal and compare the color temperature value of the light detection signal with a predetermined target color temperature value, and output the second correction signal based on the result of the comparison operation. Light generating device. The method of claim 9, The first correction unit, A first memory unit storing the target luminance value; And Reading the stored target luminance value, calculating a difference value between the read target luminance value and the luminance value of the light detection signal, and correcting the luminance value of the light detection signal based on the difference value; It includes a luminance correction unit for outputting data, The second correction unit, A second memory unit storing the target color coordinate value; And Reading the stored target color coordinate value to calculate a difference value between the read target color coordinate value and a color coordinate value corresponding to the light detection signal, and correcting the color temperature value of the light detection signal based on the difference value; And a color temperature correction unit for outputting correction data. The method of claim 10, wherein the color temperature correction unit, An XYZ conversion unit receiving the light detection signal and converting the input light detection signal into an XYZ value of a CIE coordinate system; A chromaticity calculator which calculates a raw X coordinate of the light detection signal based on a distribution of color temperature values of the CIE coordinate system and calculates a raw Y coordinate based on the calculated raw X coordinate; The target color temperature value stored in the second memory unit is read to calculate a target X coordinate and a target Y coordinate corresponding to the read target color temperature value, and an X coordinate difference value between the target X coordinate and the original X coordinate and the target Compensating the Y coordinate difference value between the Y coordinate and the raw Y coordinate, and correcting the raw X coordinate and the raw Y coordinate based on the X coordinate difference and the Y coordinate difference value, respectively. A coordinate corrector that outputs the coordinates; And And a color temperature converter configured to correct a color temperature value of the light detection signal based on the corrected X coordinate and the corrected Y coordinate, and output the second correction data corresponding to the corrected color temperature value. . A display unit for displaying an image corresponding to an image signal provided from an external image signal source using white light; And A light generating device formed under the display unit to generate the white light; The light generating device, Receives a plurality of image data, detects and outputs a plurality of luminance data corresponding to the plurality of image data, compares the plurality of gray levels corresponding to the plurality of image data with a reference gray level, and based on the comparison result A luminance detector for outputting an enable signal; A dimming signal controller configured to receive a correction signal and the luminance data and output a first dimming signal corresponding to the luminance data and a second dimming signal correcting the first dimming signal based on the correction signal; A light source driver configured to output a driving signal in response to any one of the first and second dimming signals from the dimming signal controller; A light source unit including a plurality of light sources generating white light in response to the driving signal; And And a light source compensator which starts driving in response to the enable signal and outputs the correction signal to receive the white light emitted from the light source and correct the optical characteristic of the white light. The method of claim 12, And each of the plurality of light sources includes a red light emitting diode, a green light emitting diode, and a blue light emitting diode. The method of claim 12, wherein the brightness detector, An enable signal generation unit which receives the plurality of image data and generates and outputs the enable signal when a plurality of gray levels corresponding to the plurality of image data are larger than the reference gray level; And And a luminance data extractor for extracting luminance data from the image data. The method of claim 12, And the optical characteristic of the white light is a luminance value. The method of claim 12, And the optical characteristic of the white light is any one of color coordinates and color temperature. The method of claim 12, The reference gray level is a display device, characterized in that the gray level corresponding to 1/2 of the entire gray scale interval. The method of claim 17, And the dimming signal controller outputs a dimming signal having a preset maximum duty ratio when the plurality of image data are all equal to or greater than the reference gray level. In the driving method of a light generating device comprising a plurality of light source units for generating white light in response to a drive signal, Receiving image data from the outside; Extracting luminance data from the image data, and comparing the gray level of the image data with a reference gray level; Outputting a dimming signal of any one of a first dimming signal corresponding to the luminance data and a second dimming signal correcting the first dimming signal based on the comparison result; Generating the driving signal corresponding to the output dimming signal; And And emitting white light from the light source unit in response to the drive signal.

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