KR101422600B1 - Liquid Crystal Display without motion blur and driving method of the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device that estimates a motion of an image displayed on a liquid crystal display device and removes motion blur that occurs according to the result, will be.

The present invention estimates a moving distance of an image, applies motion sharpness according to the result, prevents a motion blur, and prevents a ghost image that may be caused in an image due to the application of sharpness. .

Motion blur, impulse type, ghost image, motion estimation,

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a liquid crystal display device and a driving method thereof,

FIGS. 1A and 1B are graphs showing the voltage level of a data signal and the size of a backlight according to time in a data blinking method and a backlight scanning type liquid crystal display device.

2A is a block diagram schematically illustrating a conventional 120 Hz driving MEDI scheme.

2B is a flowchart for explaining the MEDI operation.

2C is a graph for explaining the MEDI operation.

Figs. 3A and 3B are views showing images within the optimum range of movement distance of the sharpness and outside the optimum range of movement distance of the sharpness. Fig.

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

5A and 5B are views for explaining the shape of motion blur according to the moving distance of the object image in the image.

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

Description of the Related Art

20: external system 100: liquid crystal panel

200: driving circuit section 230: interface

240: memory unit 250: blur rejection

260: timing controller 270: gate driver

280: data driver 300: backlight device

310: backlight lamp 320: lamp driver

400:

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device which estimates a motion of an image displayed on a driving liquid crystal display device and removes a motion blur generated according to the result, .

As is well known, a liquid crystal has an optical anisotropy in which the molecular structure is thin and long and has a direction in the arrangement, and a molecular alignment in accordance with the size when it is placed in an electric field, as a general liquid crystal display device has an image realization principle using optical anisotropy and polarization property of liquid crystal. The polarization direction is changed.

The liquid crystal display device includes a liquid crystal panel in which a pair of substrates each having a transparent electric field generating electrode formed on a surface thereof facing each other with a liquid crystal layer interposed therebetween and a liquid crystal panel The arrangement direction of the liquid crystal is artificially adjusted according to the magnitude of the electric field between the two electric field generating electrodes so that the transmittance is made different and then the light emitted from the backlight device is passed therethrough so that the difference in transmittance is externally manifested, Is displayed.

Unlike an impulse type CRT display device widely used in the past, such a liquid crystal display device is a hold type in which the lamp is kept on continuously during a period of displaying an image In general, when a response speed of liquid crystal is smaller than one frame, the liquid crystal display device of the hold type generates motion blur which can not display a clear image.

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

FIGS. 1A and 1B are graphs showing the voltage level of a data signal and the size of a backlight according to time in a data blinking method and a backlight scanning type liquid crystal display device, which are impulse driving methods of a liquid crystal display to be. As shown in FIG. 1A, in a data blinking liquid crystal display device, a light source of a backlight is the same as the conventional one but is divided into a display period and a non-display period of an actual image for one frame, A normal data signal is inputted to the display section of the image and an impulse method is implemented by inputting the black data signal to the non-display section.

In addition, as shown in FIG. 1B, in the backlight scanning type liquid crystal display device, the data signal input mode is the same as that of the related art. However, during the one frame period, the display period of the actual image and the non- Thereby implementing the impulse method by turning on the backlight at the time of displaying the image and turning off the backlight at the non-display period of the image.

In the data blinking method, since an actual image and a black image are to be displayed during one frame period, a black signal is applied to a non-display period in one frame as compared with a general liquid crystal display device, There are disadvantages.

In order to improve the above disadvantages, a Motion Estimated Data Insertion (MEDI) method has been proposed in which a high-speed driving is performed at a frequency of 120 Hz or more, and an intermediate image is generated and inserted between existing pre / post frames.

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

2A and 2B, the MEDI system includes an image converting apparatus 1, and the image converting apparatus 1 includes a frame rate converter 4 for determining a driving frequency of a liquid crystal display And an image converter 6 for receiving and comparing the original data signal data_o of the previous and next frames and generating an insert data signal data_i through the comparison.

First, the frame rate converter 4 converts the frame rate from 60 Hz to 120 Hz at step S1 in the driving apparatus of the liquid crystal display apparatus. Thereafter, the original data signal (data_o) of the n-th frame is inputted to the image converter 6 and temporarily stored in the memory (S2). The original data signal data_o of the (n + 1) th frame is received and compared with the original data signal data_o of the nth frame, and the inserted data signal data_i is generated in accordance with the difference.

More specifically, the insert data signal (data_i) receives the original data signal (data_o) of the nth frame temporarily stored and the original data signal (data_o) of the (n + 1) And calculates a median value thereof.

In other words, as shown in Fig. 2C, if an arbitrary A picture A positioned at (x, y) in the nth frame moves to (x ', y') point in the (n + 1) , B image B at a point (x '', y "') which is an intermediate value between the point (x, y) and the point (x', y ' .

Thereafter, the inserch data signal data_i of one frame is inserted between the nth frame data signal data_o and the (n + 1) th frame data signal data_o and outputted (S5).

Through such an apparatus and step, the conventional MEDI type liquid crystal display device gives the observer an image displayed for the same period twice at a high rate, so that the observer perceives the image with reduced motion blur.

However, when a liquid crystal display device of the MEDI type is implemented, the following drawbacks exist.

As a first problem, the frequency of the liquid crystal display must be doubled to increase the power consumption.

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

SUMMARY OF THE INVENTION It is an object of the present invention to provide a backlight device in which motion blur is more effectively removed at 60 Hz driving in order to overcome such disadvantages, a liquid crystal display including the same, and a driving method thereof.

According to an aspect of the present invention, there is provided a liquid crystal display device including a liquid crystal panel; An interface for transferring a control signal and a data signal; A memory unit for storing data signals transmitted from the interface on a frame basis; Estimating a movement distance of the image through the data signal stored in the memory unit to determine whether to perform contour enhancement of the image, and re-arranging the data signal to which the contour enhancement is applied to supply the liquid crystal panel with the control signal, A driving circuit for controlling the liquid crystal panel; A backlight device for supplying light to the liquid crystal panel; And a power supply unit for supplying driving power to the liquid crystal panel, the driving circuit unit, and the backlight unit.

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

Wherein the driving circuit section includes: blur removal means for estimating a movement distance of an image through the data signal and determining whether to emphasize the contour of an image according to the moving distance, and applying the emphasis to the data signal according to the blur elimination; A control signal generator for generating a driving control signal for driving the liquid crystal panel; a timing controller for rearranging a data signal to which contour emphasis of the image is applied; A gate driver for controlling the liquid crystal panel in response to the drive control signal; And a data driver for converting the rearranged data signal into a video signal corresponding to the driving control signal and supplying the video signal to the liquid crystal panel.

The blur removing unit may include a motion estimator for comparing a data signal stored in the first and second memory units and estimating a moving distance of the image; And an outline emphasis unit for determining whether or not to outline the data signal according to the estimation result of the motion estimation unit and applying the outcome.

And the liquid crystal panel and the driving circuit section operate at 60 Hz.

According to another aspect of the present invention, there is provided a method of driving a liquid crystal display device including a liquid crystal panel, an interface for transmitting a control signal and a data signal, a memory unit for storing a data signal, A driving circuit for compensating the data signal according to the moving distance of the image and supplying the compensated data signal to the liquid crystal panel, and for controlling the liquid crystal panel by receiving the control signal, a backlight device, and a power source A driving method of a liquid crystal display device in which blur is removed, the method comprising: storing the data signal; Estimating a moving distance of the image through the stored data signal; Determining whether the contour of the image is emphasized according to the estimated result; And compensating the data signal according to whether the contour of the image is emphasized.

The step of storing the data signal is a step of storing the data signal in units of n frames and n + 1 frames, respectively.

Wherein the step of estimating the moving distance of the image through the data signal is a step of comparing the stored n frame data signal with the stored n + 1 frame data signal, and removing the motion blur .

The step of compensating the data signal may be such that when the movement distance of the image displayed by the data signal is small or small, the contour enhancement of the image is not applied to the data signal, And applying the outline enhancement of the image to the data signal and outputting the data signal.

And the liquid crystal panel and the driving circuit section operate at 60 Hz.

The LCD device according to the embodiment of the present invention is distinguished from the conventional art by removing motion blur by applying sharpness to an image according to the shape of an input image.

The sharpness technique is an image processing technique for eliminating motion blur of an image by emphasizing and displaying an edge portion of an image to be displayed, that is, an outline of an image, rather than an original image. It is possible to effectively remove the motion blur of the picture as shown in the drawing before and after the technique.

However, such a sharpness technique has a limited range of the optimum sharpness setting depending on the moving distance of an image. 3A shows an image within the optimum range of movement distance of the preset sharpness. When the image is out of the optimum movement distance range, as shown in FIG. 3B, (Ghost Image) is generated.

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

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

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

As shown in the figure, a liquid crystal display device according to an embodiment of the present invention includes a liquid crystal panel 100 for displaying an image, a liquid crystal panel 100 driven by control signals and data signals supplied from an external system 20 And a backlight unit 300 provided on the rear surface of the liquid crystal panel 100 and supplying light.

More specifically, in the liquid crystal panel 100, a plurality of gate lines GL and data lines DL are arranged in a matrix, and switching elements and pixel electrodes connected thereto are provided at the intersections The switching device includes a first substrate made of a thin film transistor (T), a second substrate bonded to the first substrate with a predetermined distance therebetween, and having a common electrode corresponding to the pixel electrode to form a liquid crystal capacitor, And a liquid crystal layer formed between the first and second substrates.

The driving circuit unit 200 includes an interface 230 for connecting the external system 20 and the driving circuit unit 200 and an interface 230 for receiving a data signal supplied from the external system 20, A memory unit 240 for temporarily storing the data signals in units of a predetermined number of bits and a plurality of memory cells in the memory unit 240; And a timing controller 260 provided at the side of the liquid crystal panel 100 for controlling the scanning and video signals 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 for supplying the data to the panel 100.

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

The timing controller 260 includes a blur eliminating unit 250 that removes motion blur according to the moving distance of the image. The blur removing unit 250 may include a blur eliminating unit 250, which is not included in the timing controller 260, And may be configured in the driver circuit portion 200 as an IC.

The backlight device 300 includes a plurality of backlight lamps 310 as a light source and a lamp driver 320 for turning on and off the backlight lamp 310 according to a control signal supplied from the timing controller 260. [ ).

The power supply unit 400 generates the common voltage Vcom of the liquid crystal panel 100 and the driving power voltage of the driving circuit unit 200 and the backlight unit 300 and supplies the same.

Hereinafter, the operation of the liquid crystal display device in which the motion blur is removed according to the embodiment of the present invention will be described with reference to the drawings.

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

The control signal is input to a timing controller 260. The timing controller 260 generates a gate driving signal and a data driving signal for controlling the gate and data drivers 270 and 280. [ In addition, the timing controller 260 rearranges the data signal in a form that can be processed by the data driver 280, and supplies the data driver 280 with the data signal.

The blur elimination unit 250 incorporated in the timing controller 260 compares the data signal of the previous frame stored in the memory unit 240 with the data signal of a subsequent frame to be inputted thereafter, And the data signal stored in the memory unit 240 is compensated for and restored.

5A and 5B, there is shown an example of an image representing the movement of an object image (OI) moving at a specific position of an image displayed on the liquid crystal panel 100, A motion blur does not occur in a fixed background image (BI) 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 hardly appears, and when the moving distance d2 of the object image OI is large, It becomes remarkably 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. When the moving distance d2 of the object image OI is large, And the outline portion of the image is compensated for and displayed more sharply.

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

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

The backlight device 300 irradiates the liquid crystal panel 100 with light corresponding to the backlight driving signal supplied from the timing controller 260.

Here, the backlight driving signal controls a duty ratio of the backlight lamp 310, and turns on / off the backlight lamp 310 through the signal.

In the liquid crystal panel 100, the thin film transistor T provided in response to the gate driving signal is turned on and a video signal is supplied to the pixel electrode connected thereto. Accordingly, the light transmittance of the liquid crystal layer is adjusted by an electric field formed between the pixel electrode and the common electrode.

Through this operation, the liquid crystal display according to the embodiment of the present invention displays the image obtained by removing the motion blur by applying the sharpness technique on a block-by-block basis according to the image displayed on one screen.

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

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

First, the memory unit 240 includes two or more first and second memories 241 and 242, each storing an image of one frame, and the first and second memories 241 and 242 are connected to the interface 230 Th frame data signal and the (N + 1) th frame data signal, respectively.

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

Hereinafter, the operation 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 the (n + 1) And is stored in the memory 241.

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

The blur elimination unit 250 analyzes the data signals of the frame units stored in the first and second memories 241 and 242 to determine the moving distance of the image, and determines whether the sharpness is achieved. 5A and 5B, when the moving distance d1 of the object image OI displayed by the image is small (FIG. 5A), the motion estimating unit 252 calculates the distance d1 to the contour enhancing unit 256 5B), the motion estimation unit 252 calculates the motion amount of the object image OI based on the movement distance d2 of the object image OI, And outputs an enable signal to the image processor 256 to apply sharpness to the data signal of the object image OI to more accurately compensate the contour portion of the object image OI.

Thereafter, the compensated data signal is supplied to the data processing unit 266 of the timing controller 260, and the data processing unit 266 rearranges and outputs the compensated data signal in a form that can be processed by the drive driver.

Through this operation, in the embodiment of the present invention, whether or not the sharpness is applied is determined according to the moving distance of the image.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It can be understood that

Therefore, the liquid crystal display device and the driving method thereof, in which the motion blur is eliminated according to the embodiment of the present invention, estimates the moving distance of the image, applies motion compensation to the image by applying the sharpness, It is possible to prevent a ghost image from being generated, thereby realizing a clearer image quality even when driving at 60 Hz.

Claims (10)

A liquid crystal panel; An interface for transferring a control signal and a data signal; A memory unit for storing data signals transmitted from the interface on a frame basis; Wherein the control unit analyzes the data signal of the frame unit stored in the memory unit to grasp a moving distance of the object image in an image including a moving object image and a fixed background image, The sharpness is applied to the data signal and the data signal is rearranged and supplied to the liquid crystal panel when sharpness is not applied to the data signal and the moving distance of the object image is larger than the reference distance, A driving circuit for receiving the control signal and controlling the liquid crystal panel; A backlight device for supplying light to the liquid crystal panel; A power supply unit for supplying driving power to the liquid crystal panel, the driving circuit unit, and the backlight unit; And wherein the liquid crystal display device is a liquid crystal display device. The method according to claim 1, Wherein the memory unit includes a first memory and a second memory for respectively storing the data signals of n frames and n + 1 frames, respectively. 3. The method of claim 2, The driving circuit unit includes: A blur removing unit for estimating a moving distance of the object image through the data signal and determining whether the sharpness is applied to the data signal and applying the sharpness to the data signal, A control signal generator for generating a drive control signal for driving the liquid crystal panel; a timing controller for rearranging the data signal;  A gate driver for controlling the liquid crystal panel in response to the drive control signal; A data driver for converting the rearranged data signal into a video signal corresponding to the driving control signal and supplying the video signal to the liquid crystal panel; And wherein the liquid crystal display device is a liquid crystal display device. The method of claim 3, Wherein the blur- A motion estimator for comparing the data signals stored in the first and second memory units and estimating the moving distance of the object image; And a contour emphasis unit for determining whether the sharpness is applied to the data signal according to the estimation result of the motion estimator and applying the sharpness to the data signal, And wherein the liquid crystal display device is a liquid crystal display device. The method according to claim 1, Wherein the liquid crystal panel and the driving circuit are operated at 60 Hz. A liquid crystal panel, an interface for transmitting a control signal and a data signal, a memory for storing the data signal, and a controller for compensating the data signal according to the moving distance of the object image displayed by the image, A driving method of a liquid crystal display device in which a motion blur is removed, the driving circuit including a driving circuit for receiving a signal and controlling the liquid crystal panel, a backlight device, and a power source, Storing the data signal; Estimating a moving distance of the object image in an image including a moving object image and a fixed background image by analyzing the stored data signal; Determining whether sharpness is applied to the data signal when the moving distance of the object image is smaller than the reference distance and when the moving distance of the object image is larger than the reference distance according to the estimated result; Compensating the data signal according to whether the sharpness is applied by comparing the movement distance and the reference distance And removing the motion blur, wherein the motion blur is eliminated. The method according to claim 6, Wherein the step of storing the data signal comprises: And storing the data signal in units of n frames and n + 1 frames, respectively. 8. The method of claim 7, Wherein the step of estimating the moving distance of the object image by analyzing the data signal comprises: And comparing the stored n frame data signal with the stored n + 1 frame data signal. The method according to claim 6, The step of compensating the data signal comprises: The sharpness is not applied to the data signal when the moving distance of the object image is smaller than the reference distance and the sharpness is applied to the data signal when the moving distance of the object image is larger than the reference distance Wherein the step of removing the motion blur includes the step of removing the motion blur. The method according to claim 6, Wherein the liquid crystal panel and the driving circuit section operate at 60 Hz.

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