KR20080078770A - Liquid crystal display without motion blur and driving method of the same - Google Patents

Abstract

An LCD device without motion blur and a method for driving the same are provided to prevent the motion blur by applying sharpness based on an estimated movement distance of images. An LCD(Liquid Crystal Display) device without motion blur includes an LCD panel(100), an interface(230), a memory(240), a driver(200), a backlight(300), and a power supply unit(400). The interface delivers control and data signals. The memory stores data signals delivered from the interface. The driver determines whether an outline of images is emphasized by estimating a movement distance of the images through the data signals stored in the memory, realigns the data signals based on the emphasized outline of the images, supplies the realigned data signals to the LCD panel, and controls the LCD panel by receiving the control signal. The backlight supplies light to the LCD panel. The power supply unit supplies a driving voltage to the LCD panel, driver, and the backlight.

Description

Liquid Crystal Display without motion blur and driving method of the same}

1A and 1B are graphs showing the voltage level of the data signal and the size of the backlight light over time of the data blinking and backlight scanning liquid crystal displays.

Figure 2a is a block diagram schematically showing a conventional 120Hz drive MEDI scheme.

2B is a flowchart for explaining the MEDI operation.

2C is a graph for explaining the MEDI operation.

3A and 3B are diagrams showing images in the optimum moving distance range of sharpness and outside the optimum moving distance range of sharpness.

FIG. 4 is a block diagram schematically illustrating a structure of a liquid crystal display without motion blur according to an exemplary embodiment of the present invention.

5A and 5B are diagrams for describing a shape of a motion blur according to a moving distance of an object image in an image.

FIG. 6 is a block diagram illustrating in detail the memory unit and the timing controller shown in FIG. 4.

<Description of the symbols for the main parts of the drawings>

20: external system 100: liquid crystal panel

200: drive circuit 230: interface

240: memory unit 250: blur removal unit

260: timing controller 270: gate driver

280: data driver 300: backlight device

310: backlight lamp 320: lamp driver

400: power supply

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device. More particularly, the present invention relates to a liquid crystal display device and a driving method thereof in which motion of an image displayed on a driving liquid crystal display device is estimated, and motion blur generated according to the result is removed. It is about.

A general liquid crystal display device has an image realization principle using optical anisotropy and polarization property of liquid crystal. As is well known, liquid crystal has a thin and long molecular structure and has an optical anisotropy having an orientation in an array and a molecular arrangement depending on its size when placed in an electric field. It is polar in nature with its changing direction.

Accordingly, the liquid crystal display device includes a liquid crystal panel in which a pair of substrates on which a transparent field generating electrode is formed on a surface facing each other with a liquid crystal layer interposed therebetween is bonded to each other and a driving circuit provided separately. By adjusting the arrangement direction of the liquid crystals according to the electric field size between the two field generating electrodes, the transmittance is different, and then the light emitted from the backlight device is passed through to allow the difference in the transmittance to be expressed to the outside. The image to be displayed is displayed.

Unlike the impulse type CRT display device which is widely used in the related art, the liquid crystal display device is a hold type in which the lamp is continuously kept on for an image display period. In general, a hold type liquid crystal display device may generate a motion blur that does not display a clear image when the response speed of the liquid crystal is smaller than one frame.

In order to solve the above problems, various types of methods for driving the liquid crystal display device in an impulse method have been proposed. As a representative example of the impulse driving method of the liquid crystal display device, a data blinking method and a backlight scanning ( Backlight scanning).

1A and 1B are graphs illustrating voltage levels of data signals and magnitudes of backlight light over time of an impulse driving method of a liquid crystal display, a data blinking method and a backlight scanning method. to be. As shown in FIG. 1A, a data blinking liquid crystal display device has the same light source as a conventional light source, but is divided into a display section and a non-display section of an actual image for one frame. An impulse method is implemented by inputting a normal data signal into a display section of an image and a black data signal into the non-display section.

In addition, as shown in FIG. 1B, in the backlight scanning type liquid crystal display device, the input form of the data signal is the same as in the related art, but as described above, the display section of the actual image and the non-display section of the image for one frame are as described above. In this case, the impulse method is implemented by turning on the backlight when the image is displayed and turning off the backlight in the non-display period of the image.

Among them, since the data blinking method should display a real image and a black image during one frame period, the luminance is reduced by about 1/2 because a black signal is applied to a non-display period in one frame compared to a general LCD. There are disadvantages.

In order to remedy this disadvantage, a Motion Estimated Data Insertion (MEDI) method has been proposed that drives at high speeds of more than 120Hz and generates and inserts intermediate images between existing front and rear frames.

FIG. 2A is a block diagram schematically illustrating a conventional 120 Hz driving MEDI scheme, and FIG. 2B is a flowchart illustrating the MEDI operation.

2A and 2B, the MEDI scheme includes an image converting apparatus 1, and the image converting apparatus 1 includes a frame rate converter 4 for determining a driving frequency of the liquid crystal display. And an image converter 6 which receives and compares the original data signal data_o of the front and rear frames, and generates an insert data signal data_i.

Referring to the operation of the image converting device 1, first, the frame rate converter 4 converts the driving frequency of the driving device of the liquid crystal display device from 60 Hz to 120 Hz (S1). Thereafter, the raw data signal data_o of the nth frame is input to the image converter 6, and is temporarily stored in the provided memory (S2). In addition, the raw data signal data_o of the n + 1 th frame is input, compared with the raw data signal data_o of the n th frame, and an insult data signal data_i is generated in response to the difference.

In more detail, the insert data signal data_i receives the temporarily stored original data signal data_o of the nth frame and the original data signal data_o of n + 1 frames, and compares the original data signal data_o to determine the moving distance of the image. The resultant signal is read out and the intermediate value thereof is calculated.

In other words, as shown in Fig. 2C, if any A picture A located at the point (x, y) in the nth frame moves to the point (x ', y') in the n + 1th frame, , B image (B) is created at the intermediate value of the moving distance of the A image, that is, the (x '', y '') intermediate value between the (x, y) point and the (x ', y') point. .

Subsequently, an insert data signal data_i of one frame is inserted and output between the n th frame data signal data_o and the n + 1 th frame data signal data_o (S5).

Through such a device and a step, the conventional MEDI type liquid crystal display device provides the viewer with an image displayed twice during the same period at a twice higher rate, whereby the viewer perceives the image with reduced motion blur.

However, the implementation of the MEDI type liquid crystal display device has the following disadvantages.

As a first problem, power consumption increases when the frequency of the liquid crystal display device needs to be doubled.

As a second problem, driving at 120 Hz is difficult to implement a circuit, and an image converter for implementing MEDI should be further provided. As a result, the manufacturing cost increases.

An object of the present invention is to provide a backlight device which removes motion blur more effectively in 60Hz driving, a liquid crystal display including the same, and a driving method thereof to overcome this disadvantage.

In order to achieve the above object, a liquid crystal display device with motion blur removed according to a preferred embodiment of the present invention, the liquid crystal panel; An interface for transmitting a control signal and a data signal; A memory unit for storing the data signal transmitted from the interface in units of frames; The moving distance of the image is estimated by using the data signal stored in the memory unit to determine whether to emphasize the contour of the image. Accordingly, the data signal to which the contour emphasis is applied is rearranged and supplied to the liquid crystal panel, and the control signal is transmitted. A driving circuit unit which receives and controls the liquid crystal panel; A backlight device for supplying light to the liquid crystal panel; And a power supply unit supplying driving power to the liquid crystal panel, the driving circuit unit, and the backlight device.

The memory unit may include a first memory and a second memory for storing the data signals of n frames and n + 1 frames, respectively.

The driving circuit unit estimates a moving distance of the image based on the data signal and determines whether or not to emphasize the outline of the image accordingly, and accordingly a blur remover for applying the emphasis to the data signal and the control signal. A control signal generator for generating a drive control signal for driving the liquid crystal panel, and a timing controller for rearranging a data signal to which the contour emphasis of the image is applied; A gate driver controlling the liquid crystal panel in response to the driving control signal; And a data driver for converting the rearranged data signal into an image signal and supplying the image signal to the liquid crystal panel in response to the driving control signal.

The blur removal unit includes: a motion estimation unit for estimating a moving distance of an image by comparing data signals stored in the first and second memory units; According to the estimation result of the motion estimation, it is characterized in that it comprises a contour emphasis unit for determining whether to emphasize the contour of the data signal, and apply this.

The liquid crystal panel and the driving circuit unit is characterized by operating at 60hz.

In order to achieve the above object, a method of driving a liquid crystal display device without motion blur according to a preferred embodiment of the present invention includes a liquid crystal panel, an interface for transmitting control signals and data signals, and a memory unit for storing data signals. And a driving circuit unit for compensating the data signal according to a moving distance of an image and supplying the data signal to the liquid crystal panel and receiving the control signal to control the liquid crystal panel, a backlight device, and a power supply unit. A method of driving a liquid crystal display device with blurring, the method comprising: storing the data signal; Estimating a moving distance of an image based on the stored data signal; Determining whether to emphasize the outline of the image according to the estimated result; Compensating for the data signal according to whether the outline of the image is emphasized.

The storing of the data signal may include storing the data signal in units of n frames and n + 1 frames, respectively.

The estimating of the moving distance of the image based on the data signal may include removing the motion blur, wherein the stored n frame data signal is compared with the stored n + 1 frame data signal. .

Compensating the data signal, if the moving distance of the image displayed by the data signal is small or small, do not apply the contour emphasis of the image to the data signal, the moving distance of the image displayed by the data signal is large In this case, it is a step of outputting by applying contour emphasis of the image to the data signal.

The liquid crystal panel and the driving circuit unit is characterized in that it operates at 60hz.

The liquid crystal display according to the exemplary embodiment of the present invention is characterized by eliminating motion blur by applying a sharpness technique to an image according to the shape of an input image.

The sharpness technique is an image processing technique that removes motion blur of an image by emphasizing an edge portion of an image to be displayed, that is, a contour line of an image than an original image, and is sharpness in the same image illustrated in FIG. 3A. As shown in the figure before and after the technique, the motion blur of the image can be effectively removed.

However, this sharpness technique is limited in the optimum sharpness setting range according to the moving distance of the image. In other words, the drawing shown in FIG. 3A is a view showing an image within an optimum moving distance range of a preset sharpness, and when it is out of the optimum moving distance range, as shown in FIG. 3B, before and after moving images are simultaneously displayed. Ghost image will be generated.

Accordingly, the embodiment of the present invention proposes a liquid crystal display device to which the sharpness processing method is applied in consideration of the moving distance of an image.

Hereinafter, a liquid crystal display and a driving method thereof having the motion blur removed according to an embodiment of the present invention will be described with reference to the accompanying drawings.

4 is a block diagram schematically illustrating a structure of a liquid crystal display device with motion blur removed according to an embodiment of the present invention.

As shown in the drawing, the liquid crystal display according to the exemplary embodiment of the present invention drives the liquid crystal panel 100 through a liquid crystal panel 100 displaying an image and a control signal and a data signal supplied from an external system 20. The driving circuit unit 200 and the backlight device 300 are provided on the rear surface of the liquid crystal panel 100 to supply light.

In more detail, the liquid crystal panel 100 includes a plurality of gate lines GL and data lines DL intersected in a matrix form, and a switching element and a pixel electrode connected thereto are provided at the intersection points. The switching element may include a first substrate formed of a thin film transistor (T), a second substrate bonded to the first substrate by a predetermined distance, and provided with a common electrode forming a liquid crystal capacitor in correspondence with the pixel electrode; It consists of a liquid crystal layer formed between a 1st and 2nd board | substrate.

The driving circuit unit 200 receives an interface 230 connecting the external system 20 and the driving circuit unit 200 and a data signal connected to the interface 230 and supplied from the external system 20 to receive the data signal. A memory unit 240 for temporarily storing data in units of) and a control signal from an external system 20, and controls the gate and data drivers 270 and 280 correspondingly, and stores the data signal stored in the memory unit. Is provided at the side end of the timing controller 260 and the liquid crystal panel 100, and the scan signal and the image signal are transferred through the gate line GL and the data line DL under the control of the timing controller 260. And a gate and data drivers 260 and 270 supplied to the panel 100.

Although not shown, the memory unit 240 includes at least one memory (not shown) and is not limited to a particular type of memory.

In addition, the timing controller 260 includes a blur remover 250 that removes motion blur according to the moving distance of the image, which is not included in the timing controller 260 according to a designer's intention, It may be configured in the driving circuit unit 200 as an IC.

The backlight device 300 includes a plurality of backlight lamps 310, which are light sources, and a lamp driver 320 that turns on / off the backlight lamp 310 according to a control signal supplied from the timing controller 260. It is composed of

In addition, the power supply unit 400 generates and supplies the common voltage Vcom of the liquid crystal panel 100 and the driving power supply voltages of the driving circuit unit 200 and the backlight device 300.

Hereinafter, an operation of a liquid crystal display without a motion blur according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, a control signal and a data signal supplied from the external system 20 are input to the memory unit 240 through the interface 230, and the data signal is temporarily stored in the memory unit 240 in units of one frame.

In addition, the control signal is input to the timing controller 260, the timing controller 260 generates a gate drive signal and a data drive signal for controlling the gate and data drivers (270, 280). In addition, the timing controller 260 rearranges the data signal into a form that the data driver 280 can process, and supplies the data signal to the data driver 280.

In addition, the blur removing unit 250 included in the timing controller 260 compares the data signal of the previous frame stored in the memory unit 240 with the data signal of the subsequent frame input thereafter, thereby moving the image. The distance is measured and the data signal stored in the memory unit 240 is compensated and stored again.

In more detail, referring to FIGS. 5A and 5B, an example of an image in which an image displayed on the liquid crystal panel 100 displays a movement of an object image (OI) moving at a specific position is described. Motion Blur does not occur in a fixed background image except for the image OI.

However, when the moving distance d1 of the moving object image OI is small, the motion blur MB1 is small or almost absent. When the moving distance d2 of the object image OI is large, the motion blur MB1 is It becomes prominent.

Therefore, when the moving distance d1 of the object image OI is small, the original data signal is displayed as it is without applying sharpness to the data signal, and when the moving distance d2 of the object image OI is large, the data signal Sharpness is applied to the image to compensate for the outline of the image.

Again, referring to FIG. 4, the gate driver 270 generates a scan signal under the control of the timing controller 260 and sequentially supplies the scan signal to the liquid crystal panel 100 through the gate line GL to supply the liquid crystal panel 100. So that the pixels are selected by one horizontal line.

The data driver 270 supplies an image signal to each pixel on the liquid crystal panel 100 through the data line DL whenever the gate line GL is sequentially selected under the control of the timing controller 260. Done.

The backlight device 300 emits light onto the liquid crystal panel 100 in response to the backlight driving signal supplied from the timing controller 260.

Here, the backlight driving signal is a signal for controlling the duty ratio of the backlight lamp 310, and through this, the backlight lamp 310 is turned on / off.

Through the above-described operation, the liquid crystal panel 100 turns on the thin film transistor T provided corresponding to the gate driving signal, and supplies an image signal to the pixel electrode connected thereto. Accordingly, the light transmittance of the liquid crystal layer is controlled by an electric field formed between the pixel electrode and the common electrode.

Through this operation, the liquid crystal display according to the exemplary embodiment of the present invention displays an image from which motion blur is removed by applying a sharpness technique in units of blocks according to an image displayed on one screen.

Hereinafter, the blur removing unit of the liquid crystal display according to the exemplary embodiment of the present invention will be described with reference to FIG. 6.

FIG. 6 is a block diagram illustrating in detail the memory unit and the timing controller shown in FIG. 4.

First, the memory unit 240 includes two or more first and second memories 241 and 242 which respectively store an image of one frame, and the first and second memories 241 and 242 may be separated from the interface 230. The data signal of the N-th frame and the N + 1-th frame data signal to be input are respectively stored.

The timing controller 260 includes a blur remover 250 for removing motion blur of an image, a control signal generator 264 for generating a control signal of a driving driver, and a data processor 266 for rearranging data signals. do. Here, the blur remover 250 includes a motion estimator 252 for estimating a moving distance of an image, and an outline emphasis unit 256 for applying sharpness to the image.

Hereinafter, operations of the memory unit 240 and the timing controller 260 will be described with reference to the drawings.

First, when a data signal from the outside is supplied to the memory unit 240 through the interface 230, the data signal of n frames is stored in the first memory 241, and then the data signal of n + 1 frames is first It is stored in the memory 241.

In addition, when the control signal is supplied to the timing controller 260 through the interface 230, the control signal generator 264 correspondingly generates a gate and data control signal for controlling the driving driver.

The blur remover 250 analyzes data signals in units of frames stored in the first and second memories 241 and 242 to determine a moving distance of the image, and thereby determine whether or not the sharpness is sharp. That is, referring again to FIGS. 5A and 5B, when the moving distance d1 of the object image OI displayed by the image is small (FIG. 5A), the motion estimator 252 is dis-ined to the outline emphasis unit 256. If the moving distance d2 of the object image OI is large (FIG. 5B) without outputting the enable signal and applying sharpness to the data signal of the corresponding object image OI, the motion estimation unit 252 is a contour emphasis unit. The enable signal is output to 256 to apply sharpness to the data signal of the object image OI, thereby compensating for the darker outline of the object image OI.

Thereafter, the compensated data signal is supplied to the data processor 266 of the timing controller 260, and the data processor 266 rearranges and outputs the compensated data signal in a form that a driving driver can process.

Through this operation, in the embodiment of the present invention, whether to apply the sharpness according to the moving distance of the image is determined.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the present invention described in the claims below I can understand that you can.

Therefore, the liquid crystal display device and the driving method thereof which remove the motion blur according to the embodiment of the present invention estimate the moving distance of the image, and prevent the motion blur by applying the sharpness according to the result, and generate the image by the sharpness. By preventing the ghost image, there is an effect to implement a clearer picture quality even when driving at 60Hz.

Claims (10)

A liquid crystal panel; An interface for transmitting a control signal and a data signal; A memory unit for storing the data signal transmitted from the interface in units of frames; The moving distance of the image is estimated by using the data signal stored in the memory unit to determine whether to emphasize the contour of the image. Accordingly, the data signal to which the contour emphasis is applied is rearranged and supplied to the liquid crystal panel, and the control signal is transmitted. A driving circuit unit which receives and controls the liquid crystal panel; A backlight device for supplying light to the liquid crystal panel; Power supply unit for supplying driving power to the liquid crystal panel, the driving circuit unit and the backlight device Liquid crystal display with a motion blur removed, comprising a. The method of claim 1, And the memory unit comprises a first memory and a second memory for storing the data signals of n frames and n + 1 frames, respectively. The method of claim 2, The driving circuit unit, Estimating the moving distance of the image based on the data signal and determining whether or not to emphasize the contour of the image, and accordingly, a blur remover for applying the emphasis to the data signal and driving the liquid crystal panel in response to the control signal. A control signal generator for generating a driving control signal for restructuring, and a timing controller for rearranging the data signal to which the contour emphasis of the image is applied;  A gate driver controlling the liquid crystal panel in response to the driving control signal; A data driver converting the rearranged data signal into an image signal and supplying the image signal to the liquid crystal panel in response to the driving control signal; Liquid crystal display with a motion blur removed, comprising a. The method of claim 3, wherein The blur removal unit, A motion estimation unit for estimating a moving distance of an image by comparing data signals stored in the first and second memory units; According to the estimation result of the motion estimation, the contour emphasis unit determines whether or not to emphasize the contour of the data signal, and applies the contour emphasis unit. Liquid crystal display with a motion blur removed, comprising a. The method of claim 1, And the liquid crystal panel and the driving circuit unit are operated at 60 hz. A liquid crystal panel, an interface for transmitting a control signal and a data signal, a memory unit for storing the data signal, and compensating the data signal according to a moving distance of an image and supplying the data signal to the liquid crystal panel. A driving circuit for controlling a liquid crystal panel, a backlight device, and a power supply unit, comprising: Storing the data signal; Estimating a moving distance of an image based on the stored data signal; Determining whether to emphasize the outline of the image according to the estimated result; Compensating the data signal according to whether the contour of the image is emphasized; Method of driving a liquid crystal display device comprising a motion blur, characterized in that it comprises a. The method of claim 6, The storing of the data signal may include: And storing the data signal in units of n frames and n + 1 frames, respectively. The method of claim 7, wherein Estimating the moving distance of the image based on the data signal, And comparing the stored n frame data signal with the stored n + 1 frame data signal. The method of claim 6, Compensating the data signal, If the moving distance of the image displayed by the data signal is small or small, the contour emphasis of the image is not applied to the data signal, and when the moving distance of the image displayed by the data signal is large, A method of driving a liquid crystal display device with motion blur removed, characterized by the step of applying contour emphasis. The method of claim 6, And the liquid crystal panel and the driving circuit unit are operated at 60 hz.

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