KR100599625B1 - A liquid crystal display and a driving method thereof - Google Patents

Abstract

The present invention relates to a liquid crystal display of a field sequential driving method for compensating for color reproducibility by changing the operation of the LED by the liquid crystal response speed slowed at a low temperature and a driving method thereof. The driving method of the liquid crystal display according to the present invention includes a liquid crystal formed between the first and second substrates, and sequentially emits light of red (R), green (G), and blue (B) to one pixel. A method of driving a liquid crystal display device, the method comprising: a) sensing a temperature or an ambient temperature of a liquid crystal panel; b) calculating a response speed of the liquid crystal corresponding to the sensed temperature; c) adjusting the length of the red (R), green (G) or blue (B) frame for each temperature in response to the response speed of the liquid crystal; And d) applying grayscale data corresponding to the adjusted frame. According to the present invention, the LED frame rate is changed without color conversion by applying white by modifying the sequential LED on / off method of red (R), green (G), and blue (B). It is possible to adjust, thereby compensating for the color reproducibility by changing the operation of the LED by the response rate of the liquid crystal slowed at low temperatures, thereby enabling the liquid crystal to be stably operated at low temperatures.

LCD, Low Temperature Drive, Frame Control, Temperature Sensor, Field Sequential Drive

Description

Liquid Crystal Display and Driving Method {A LIQUID CRYSTAL DISPLAY AND A DRIVING METHOD THEREOF}

1A is a diagram illustrating a pixel of a conventional liquid crystal display.

1B is a waveform diagram illustrating a driving method of a conventional analog liquid crystal display device.

1C is a waveform diagram illustrating a driving method of a conventional digital liquid crystal display device.

2 is a view showing a conventional liquid crystal display device.

3 is a view showing a method of driving a liquid crystal display according to the related art.

4 is a diagram illustrating a driving method of a liquid crystal display according to an exemplary embodiment of the present invention.

5 is a diagram illustrating adjusting a frame when driving a liquid crystal display according to an exemplary embodiment of the present invention.

6 is a diagram illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

The present invention relates to a liquid crystal display device and a driving method thereof, and more particularly, to a liquid crystal display device having a field sequential driving method for compensating for color reproducibility by changing the operation of the LED by a liquid crystal response speed slowed at a low temperature and a driving method thereof. will be.

Recently, display devices are also required to be lighter and thinner in accordance with the light weight and thickness of personal computers and televisions, and according to such demands, liquid crystal displays (hereinafter referred to as "LCDs") instead of cathode ray tubes (CRTs) are required. Flat panel displays are being developed.

The LCD applies an electric field to a liquid crystal material having an anisotropic dielectric constant injected between two substrates, and adjusts the strength of the electric field to control the light transmitted from the external light source (back-light) to the substrate. By adjusting the amount, a desired image is obtained.

Such LCDs are typical of portable flat panel displays, and among them, TFT-LCDs using thin film transistors (hereinafter referred to as TFTs) as switching elements are mainly used.

In the TFT-LCD, each pixel can be modeled as a liquid crystal capacitor because electrodes (pixel electrodes and common electrodes) are disposed to face each other with a liquid crystal interposed therebetween. In such LCDs, each pixel is represented by an equivalent circuit as shown in FIG. 1A. Can be.

As shown in Fig. 1A, each pixel of the liquid crystal display according to the prior art includes: a TFT 10 having a source electrode connected to a data line Dm and a gate electrode connected to a scan line Sn; A liquid crystal capacitor Cl connected between the drain electrode of the TFT 10 and the common electrode Vcom; And a storage capacitor Cst connected to the drain electrode of the TFT 10.

The TFT 10 provides the pixel electrode (not shown) with the data voltage Vd supplied from the data line Dm in response to the scan signal from the scan line Sn. An electric field corresponding to the difference between the data voltage provided to the pixel electrode (that is, the pixel voltage Vp and the common voltage Vcom applied to the common electrode (not shown) is equivalent to that of the liquid crystal capacitor (FIG. 1A). The liquid crystal adjusts the transmittance of light in response to the intensity of the applied electric field, and the storage capacitor Cst converts the pixel voltage provided to the liquid crystal capacitor Cl to the next data voltage Vd. The light is transmitted for a predetermined time by maintaining it until it is supplied.

In general, the LCD may be divided into two methods, a color filter method and a field sequential driving method, according to a method of displaying a color image.

A color filter type LCD forms a color filter layer consisting of three primary colors of red (R), green (G), and blue (B) on an upper substrate of a panel, and adjusts the amount of light transmitted through the color filter layer to achieve a desired image. Is displayed. However, the color filter type LCD requires unit pixels corresponding to the red (R), green (G), and blue (B) areas, and thus requires three times as many pixels as those for displaying black and white. Therefore, in order to obtain high resolution images, sophisticated manufacturing technology of LCD panels is required. In addition, in the color filter type LCD, red (R), green (G), and blue (B) color filters must be formed on the upper substrate, which is cumbersome in manufacturing, and the light transmittance of the color filter itself must be improved. There is a problem.

Field-sequential driving LCDs periodically turn on independent light sources of red (R), green (G), and blue (B) colors sequentially, and supply a pixel voltage (Vp) to each pixel at each lighting cycle. Is displayed. That is, the field-sequential driving LCD does not divide one pixel into unit pixels of red (R), green (G), and blue (B), and red (R), green (G), and blue in one pixel. (B) By time-divisionally displaying the light of three primary colors supplied from each backlight, a color image is displayed using the afterimage effect of an eye.

The field sequential driving method may be classified into an analog driving method and a digital driving method.

The analog driving method sets a plurality of gray voltages corresponding to the number of gray levels to be displayed, selects one gray voltage corresponding to gray data among the gray voltages, and drives the liquid crystal panel with the selected gray voltage, thereby applying the applied gray voltage. The gray level is expressed by the amount of transmitted light corresponding to.

FIG. 1B is a diagram illustrating a driving voltage and a transmitted light amount according to a conventional LCD driving apparatus.

In FIG. 1B, the driving voltage refers to a voltage applied to the liquid crystal and the optical transmittance refers to a transmission ratio with respect to the applied light when light is applied to the liquid crystal. That is, the light transmittance refers to the degree of twist that the liquid crystal can transmit light.

Referring to FIG. 1B, in the R field section Tr for displaying the R color, a driving voltage of the V11 level is applied to the liquid crystal so that light corresponding to the driving voltage of the V11 level passes through the liquid crystal. In the G field section Tg for displaying the G color, a driving voltage of the V12 level is applied so that light corresponding to the driving voltage of the V12 level passes through the liquid crystal. Then, in the B field section Tb for displaying the B color, a driving voltage of the V13 level is applied to obtain a light transmittance corresponding to the driving voltage of the V13 level. Therefore, the desired color image is displayed by the sum of the R, G, and B light transmitted in the Tr, Tg, and Tb field sections, respectively.

On the other hand, in the digital driving method, the driving voltage applied to the liquid crystal is made constant, and the gray scale is expressed by controlling the voltage application time. According to such a digital driving method, gray scales are represented by adjusting a cumulative amount of light transmitted through a liquid crystal by maintaining a constant driving voltage and controlling a voltage application state and a voltage non-application state in a timing manner.

FIG. 1C is a waveform diagram illustrating a conventional method for driving a liquid crystal display device of a digital driving method, and illustrates a waveform of a driving voltage according to driving data of a predetermined bit and a light transmittance of the liquid crystal accordingly.

Referring to FIG. 1C, grayscale waveform data corresponding to each grayscale is provided as a digital signal of a predetermined bit, for example, 7bit, and a grayscale waveform corresponding to the 7bit data is applied to the liquid crystal. The light transmittance of the liquid crystal is determined according to the applied gray waveform to perform gray scale display.

On the other hand, the speed of inversion of red (R), green (G), and blue (B) LEDs in field sequential driving is very important because the synthesis speed is synthesized by the human eye in time. . That is, the above-described field sequential driving LCD (FS-LCD) drives one frame into an R field, a G field, and a B field, so that the liquid crystal has a higher response speed than the color filter type LCD.

However, the liquid crystal needs to respond properly to such a high conversion speed so that the desired gray scale can be expressed. However, at low temperatures, liquid crystals are also typical of fluids, so the viscosity increases when the temperature of the fluid decreases. Therefore, the response speed is also slowed down, and because it does not correspond to the conversion of the red (R), green (G) and blue (B) of the LED, there is a problem that color distortion occurs and the color reproduction rate is lowered. That is, the lower the temperature, the lower the response speed of the liquid crystal. Therefore, when the LCD of the field sequential driving method is used for a portable device (for example, a mobile phone) that is frequently exposed to a low temperature environment, the response speed of the liquid crystal is significantly lowered. There was a problem that the color reproduction rate is lowered. Therefore, in order to compensate the response characteristics (transmission characteristics) that change with temperature in the conventional FS-LCD, the response characteristics of the liquid crystals were indirectly measured by measuring the temperature or the ambient temperature of the liquid crystal panel.

FIG. 2 is a diagram illustrating a conventional liquid crystal display device. The temperature of the FS-LCD panel 100 is measured using a temperature sensor 900, and thus response characteristics are measured. That is, in the conventional FS-LCD panel 100 to measure the temperature using the temperature sensor 900 to compensate for the change in the response speed of the panel according to the temperature, the FS-LCD panel 100 by using the temperature ) Was estimated indirectly. Each component of the liquid crystal display will be described in detail later in the present invention.

3 is a view illustrating a method of driving a liquid crystal display according to the related art, in which the R, G, and B fields for displaying light corresponding to R, G, and B are reset periods (Rreset, Greset, Breset, respectively). ) And data intervals (Rdata, Gdata, Bdata).

Referring to FIG. 3, the reset periods are sections in which reset voltages (or reset waveforms) are applied to make the liquid crystals of the gray level displayed immediately before the same state (black state). The data section (Rdata, Gdata, Bdata) is a section for applying the gray scale voltage (or gray waveform) corresponding to the gray scale to be currently displayed, and sequentially turns on the backlight for outputting light corresponding to R, G, and B in this data section. Turn on

However, in the conventional method for measuring the response speed using a temperature sensor, there is no clear relationship between the response speed of the panel and the temperature, and in particular, in the FS-LCD, since the change of the response characteristic with temperature is very nonlinear, the temperature is measured. There is a problem that it is difficult to measure the accurate response characteristics. In addition, since there is an error between the temperature measured by using the temperature sensor and the actual temperature of the liquid crystal panel, there is a problem that there is a limit in estimating the response speed of the liquid crystal panel and compensating for it when using the existing temperature sensor. .

An object of the present invention for solving the above problems is to change the operation of the LED by the liquid crystal response speed slowed at a low temperature to compensate for color reproduction, the liquid crystal display device of the field sequential driving method that can be operated stably at a low temperature It is to provide.

In addition, another object of the present invention is to modify the sequential LED on / off method of the existing red (R), green (G) and blue (B) by applying a white (white) LED without color conversion An object of the present invention is to provide a liquid crystal display device having a field sequential driving method capable of adjusting a frame rate and a driving method thereof.

As a means for achieving the above object, the liquid crystal display driving method according to the present invention,

In the driving method of the liquid crystal display device comprising a liquid crystal formed between the first and second substrate, and sequentially transmits the light of red (R), green (G), blue (B) to one pixel,

a) sensing the temperature or ambient temperature of the liquid crystal panel;

b) calculating a response speed of the liquid crystal corresponding to the sensed temperature;

c) adjusting the length of the red (R), green (G) or blue (B) frame for each temperature in response to the response speed of the liquid crystal; And

d) applying grayscale data corresponding to the adjusted frame

There is a feature that includes.

In addition, as another means for achieving the above object, the liquid crystal display device according to the present invention,

A liquid crystal panel having a liquid crystal and having an upper substrate and a lower substrate;

A temperature sensor for sensing a temperature or an ambient temperature of the liquid crystal panel;

At least three light sources sequentially outputting light of red (R), green (G), and blue (B) to each pixel disposed in the liquid crystal panel;

A light source controller which calculates a response speed of the liquid crystal when the temperature sensed by the temperature sensor is equal to or less than a predetermined temperature, and controls light emission of the red (R), green (G), and blue (B) light sources; And

Frame control unit for adjusting the size of the red (R), green (G) and blue (B) frame in response to the obtained response speed

There is a feature that includes.

In addition, as another means for achieving the above object, the liquid crystal display device according to the present invention,

A matrix form having a plurality of scan lines for transmitting a scan signal, a plurality of data lines insulated from and intersecting the scan lines, a switching element formed in an area surrounded by the scan lines and data lines, and connected to the scan lines and data lines, respectively. A liquid crystal display panel including a plurality of pixels arranged in a line;

A scan driver for sequentially supplying scan signals to the scan lines;

A gray voltage generator which generates a gray voltage corresponding to gray data;

A data driver supplying a gray voltage output from the gray voltage generator to a corresponding data line;

A light source sequentially outputting light of red (R), green (G), and blue (B) to one pixel;

A temperature sensor for sensing a temperature or an ambient temperature of the liquid crystal panel;

A light source controller which calculates a response speed of the liquid crystal when the temperature sensed by the temperature sensor is equal to or less than a predetermined temperature, and controls light emission of the red (R), green (G), and blue (B) light sources;

A frame adjusting unit which adjusts sizes of red (R), green (G) and blue (B) frames and inserts a white frame into each frame in response to the obtained response speed; And

When the temperature sensed by the temperature sensor is less than a predetermined temperature, the white (W) light source for outputting white light to each of the white frame formed in the adjusted frame

There is a feature that includes.

According to the present invention, the LED frame rate is changed without color conversion by applying white by modifying the sequential LED on / off method of red (R), green (G), and blue (B). It is possible to adjust, thereby compensating for the color reproducibility by changing the operation of the LED by the response rate of the liquid crystal slowed at low temperatures, thereby enabling the liquid crystal to be stably operated at low temperatures.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

The term "reset" described below means applying a voltage (or waveform) to make the liquid crystal material in the LCD black, which cannot transmit light. In addition, "light transmittance" refers to a ratio of transmitted light to applied light when a certain light is applied to the liquid crystal, and 'light transmittance' is the amount of light transmitted through the liquid crystal by the actual light is applied to the liquid crystal. Means.

4 is a view illustrating a method of driving a liquid crystal display according to an exemplary embodiment of the present invention. According to an exemplary embodiment of the present invention, the R field, the G field, and the B field for displaying light corresponding to R, G, and B are shown. Respective reset sections (Rreset, Greset, Breset), data sections (Rdata, Gdata, Bdata) and white sections (white).

The reset section is a section in which a reset voltage (or reset waveform) is applied to make the state of the liquid crystal by the gray scale displayed immediately before the same state (black state), respectively. In the reset periods (Rreset, Greset, Breset) of the embodiment of the present invention, reset voltages (or reset waveforms) corresponding to the immediately preceding grayscale data are sequentially applied to the scan lines S1, S2, ... Sn, respectively, to the previous grayscale. Regardless, the liquid crystals are in the same state.

The data section (Rdata, Gdata, Bdata) is a section for applying the gray scale voltage (or gray waveform) corresponding to the gray scale to be currently displayed, and sequentially turns on the backlight for outputting light corresponding to R, G, and B in this data section. Turn on In the exemplary embodiment of the present invention, the light emitting diode is described as an example of the backlight, but is not necessarily limited thereto.

In the white section, when the liquid crystal is driven at a low temperature, the response speed of the liquid crystal becomes slow. At this time, red (R), green (G), and blue (B) of the LEDs correspond to the response speed of the slow liquid crystal. In order to adjust the frame, the red (R), green (G) and blue (B) is inserted into the frame to adjust the frame length of the LED. Here, the white light source applied to the white period may be formed by simultaneously turning on the red, green, and blue LEDs. In this case, the number of LEDs may not be increased. There are advantages, but there are also disadvantages that can be mixed. Therefore, in the embodiment of the present invention, a separate white LED may be used to eliminate the possibility of mixed color.

On the other hand, as a method of including white in addition to red (R), green (G), and blue (B) in the FS driving method, although the conventional method has been used for the purpose of improving luminance, the present invention In the FS driving according to the embodiment of the present invention, at room temperature, the conventional red (R), green (G) and blue (B) LED driving is applied to use a fast liquid crystal response speed, in particular, at a low temperature of -10 ℃ or less white By matching the LED drive frame balance in each temperature step by application, the driving application environment is different.

5 is a diagram illustrating adjusting a frame when driving a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 5, when the liquid crystal is operated at a low temperature of −10 ° C. or less, each of red and green in order to increase the LED frame length of red, green, and blue colors, respectively. The (G) and blue (B) frames are increased by the response speed of the liquid crystal at the corresponding temperature. At this time, increasing the red (R), green (G) and blue (B) on time (flicker) occurs, so the conversion time of the red (R), green (G) and blue (B) remains the same. It must be maintained. Thus, for example, the frame may be increased by increasing the number of times the red R is maintained while maintaining the existing on time. In this case, when the red (R) LED is turned on, the color may be interrupted. As described above, by turning on the white (W), the color may be prevented. In addition, when the remaining green (G) or blue (B) can be driven in the same manner.

In order to adjust the frame length, the frame length may be adjusted by adjusting the number of small cycles in which the red and the white W are turned on and off once. In other words, to increase the frame length, the number of ON / OFF times of red (R) (or G, B) and white (W) is increased by an integer multiple, and conversely, it is reduced by an integer multiple.

6 is a diagram illustrating a liquid crystal display (LCD) according to an embodiment of the present invention.

Referring to FIG. 6, a liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal panel 100, a scan driver 300, a data driver 400, a gray voltage generator 500, a timing controller 600, and at least Three or more light sources 800R, 800G, and 800B, a light source controller 700, a temperature sensor 900, and a frame controller 1000. Here, the light sources 800R, 800G, and 800B may use a light emitting diode (LED) for backlighting of the liquid crystal panel 100, and may further include a white light source 800W as the light source.

The liquid crystal panel 100 includes a plurality of pixels 120 arranged in a matrix at the intersection of the scan line S and the data line D. FIG.

The timing controller 600 receives the gray level data signals R, G, and B data, the horizontal synchronization signal Hsync, and the vertical synchronization signal Vsync from an external or graphic controller (not shown), and scan scan unit 300. ), A scan control signal Sg for controlling the control panel, a data control signal Sd for controlling the data driver 400, and a light source control signal Sb for controlling the light source controller 700. The timing controller 600 supplies the gray data signals R, G, and B data to the gray voltage generator 500.

The scan driver 300 selects a horizontal line to which the data voltage Vd is supplied by sequentially supplying a scan signal to the scan line S in response to the scan control signal Sg supplied from the timing controller 600.

The gray voltage generator 500 generates a gray voltage (data voltage Vd) corresponding to the gray data signals R, G, and B DATA, and converts the generated data voltage Vd to the data driver 400. Supply. The data driver 400 supplies the data voltage Vd to the data line D while being controlled by the data control signal Sd.

The light source controller 700 may emit the light sources 800R, the green light sources 800R, the blue light sources 800G, and the blue light sources 800B in different periods of one frame in response to the light source control signal Sb. 800G, 800B). In this case, driving currents I _R , I _G , and I _B expressing color are supplied to the light sources 800R, 800G, and 800B. In addition, the light source controller 700 calculates a response speed of the liquid crystal when the temperature sensed by the temperature sensor is less than or equal to a predetermined temperature.

The frame adjusting unit 1000 adjusts the sizes of the red (R), green (G), and blue (B) frames in response to the obtained response speed. The frame adjusting unit 1000 maintains the same On time of each of the red (R), green (G), and blue (B) frames, and increases the number of on. ), A white frame is inserted into each of the green, green, and blue frames to adjust the size of the frame.

That is, the frame control unit 1000 increases or decreases the number of small cycles in which each of the red (R), green (G), or blue (B) frames and the white (W) frames are turned on and off once by an integer multiple. By adjusting the frame size.

Here, the light source applied to the white (W) frame is formed by simultaneously turning on the LEDs applied to the red (R), green (G) and blue (B) frames, or using a separate white LED (800W) Can be implemented.

As a result, the embodiment of the present invention modifies the sequential LED on / off method of red (R), green (G), and blue (B) by applying white to apply LED without color conversion. The frame rate can be adjusted, thereby compensating for the color gamut by changing the operation of the LED by the liquid crystal response speed slowed at a low temperature.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

For example, in the above-described embodiment of the present invention, the LCD of the field sequential driving method has been described as an example, but may be applied to various LCDs other than the field sequential driving LCD.

According to the present invention, the LED frame rate is changed without color conversion by applying white by modifying the sequential LED on / off method of red (R), green (G), and blue (B). It is possible to adjust, thereby compensating for the color reproducibility by changing the operation of the LED by the response rate of the liquid crystal slowed at low temperatures, thereby enabling the liquid crystal to be stably operated at low temperatures.

Claims (17)

In the driving method of the liquid crystal display device comprising a liquid crystal formed between the first and second substrate, and sequentially transmits the light of red (R), green (G), blue (B) to one pixel, a) sensing the temperature or ambient temperature of the liquid crystal panel; b) calculating a response speed of the liquid crystal corresponding to the sensed temperature; c) adjusting the length of the red (R), green (G) or blue (B) frame for each temperature in response to the response speed of the liquid crystal; And d) applying grayscale data corresponding to the adjusted frame Liquid crystal display driving method comprising a. The method of claim 1, In the step c), when the detected temperature is lower than or equal to a predetermined temperature, the size of the red (R), green (G), or blue (B) frame is adjusted according to the temperature step. The method of claim 2, And said predetermined temperature is -10 [deg.] C. The method of claim 1, In the step c), the on time of each of the red (R), green (G), and blue (B) frames is kept the same, and the number of on is increased. . The method of claim 1, In the step c), a white frame is inserted into the red, green, and blue frames, respectively, to adjust the size of the frame. The method of claim 5, The control of the frame size may increase or decrease the number of small cycles in which each of the red (R), green (G) or blue (B) frame and the white (W) frame are turned on / off once each by an integer multiple. A liquid crystal display drive method. The method of claim 5, And a light source applied to the white (W) frame is formed by simultaneously turning on LEDs applied to the red (R), green (G), and blue (B) frames. The method of claim 5, The light source applied to the white (W) frame may use a white light emitting diode (LED) in addition to the light sources applied to the red (R), green (G), and blue (B) frames. Driving method. A liquid crystal panel having a liquid crystal and having an upper substrate and a lower substrate; A temperature sensor for sensing a temperature or an ambient temperature of the liquid crystal panel; At least three light sources sequentially outputting red (R), green (G), and blue (B) light to each pixel disposed in the liquid crystal panel; A light source controller which calculates a response speed of the liquid crystal when the temperature sensed by the temperature sensor is equal to or less than a predetermined temperature, and controls light emission of the red (R), green (G), and blue (B) light sources; And Frame control unit for adjusting the size of the red (R), green (G) and blue (B) frame in response to the obtained response speed Liquid crystal display comprising a. The method of claim 9, The frame adjusting unit maintains the on time of each of the red (R), green (G), and blue (B) frames the same, and increases the number of on. The method of claim 9, The frame adjusting unit controls the size of the frame by inserting a white frame into the red (R), green (G) and blue (B) frames, respectively. The method of claim 11, The frame adjusting unit adjusts the frame size by increasing or decreasing the number of small cycles in which each of the red (R), green (G), or blue (B) frames and the white (W) frames are turned on and off once by an integer multiple. Liquid crystal display characterized in that. The method of claim 12, The light source applied to the white frame is formed by simultaneously turning on the LEDs applied to the red, green, and blue frames. A matrix form having a plurality of scan lines for transmitting a scan signal, a plurality of data lines insulated from and intersecting the scan lines, a switching element formed in an area surrounded by the scan lines and data lines, and connected to the scan lines and data lines, respectively. A liquid crystal display panel including a plurality of pixels arranged in a line; A scan driver for sequentially supplying scan signals to the scan lines; A gray voltage generator which generates a gray voltage corresponding to gray data; A data driver supplying a gray voltage output from the gray voltage generator to a corresponding data line; A light source sequentially outputting light of red (R), green (G), and blue (B) to one pixel; A temperature sensor for sensing a temperature or an ambient temperature of the liquid crystal panel; A light source controller which calculates a response speed of the liquid crystal when the temperature sensed by the temperature sensor is equal to or less than a predetermined temperature, and controls light emission of the red (R), green (G), and blue (B) light sources; A frame adjusting unit which adjusts sizes of red (R), green (G) and blue (B) frames and inserts a white frame into each frame in response to the obtained response speed; And When the temperature detected by the temperature sensor is less than a predetermined temperature, a white light source for outputting white light to each of the white frame formed in the adjusted frame Liquid crystal display comprising a. The method of claim 14, And the white light source is a white light emitting diode. The method of claim 14, The frame adjusting unit maintains the on time of each of the red (R), green (G), and blue (B) frames the same, and increases the number of on. The method of claim 14, The frame adjusting unit controls the size of the frame by inserting a white frame into the red (R), green (G) and blue (B) frames, respectively.

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