KR101816894B1 - Liquid crystal display - Google Patents

Abstract

The present invention relates to a liquid crystal display device capable of removing a motion blur while employing a backlight unit of a horizontal edge type.
The liquid crystal display device includes a liquid crystal display panel having a plurality of data lines and gate lines formed therein; A light guide plate disposed below the liquid crystal display panel and defining a first waveguide block and a second waveguide block adjacent to each other along a horizontal direction in which the gate lines extend; Light source arrays disposed on one side of the light guide plate along the horizontal direction to irradiate light to the wave guide blocks along a vertical direction in which the data lines are elongated; And timing of the light source of the light source array that emits light to the first waveguide block and the light source array that emits light to the second waveguide block are controlled differently based on the timing at which the video data is written into the liquid crystal display panel And a scanning backlight control unit.

Description

[0001] LIQUID CRYSTAL DISPLAY [0002]

The present invention relates to a liquid crystal display capable of scanning backlight driving.

BACKGROUND ART [0002] Liquid crystal display devices are becoming increasingly widespread due to features such as light weight, thinness, and low power consumption driving. This liquid crystal display device is used as a portable computer such as a notebook PC, an office automation device, an audio / video device, and an indoor / outdoor advertisement display device. A transmissive liquid crystal display device that occupies most of the liquid crystal display device controls an electric field applied to the liquid crystal layer to modulate light incident from the backlight unit to display an image.

When a moving picture is displayed through a liquid crystal display device, a motion blurring may appear due to a maintenance characteristic of the liquid crystal, such that the screen is not clear and blurred. Motion blurring is noticeable in motion pictures, and moving picture response time ("MPRT") must be reduced to eliminate motion blurring. MPRT indicates the time required until 90% of the target luminance value is achieved by the liquid crystal response. Scanning backlight driving technology has been proposed as a way to reduce MPRT. The scanning backlight driving technique sequentially flashes the light sources of the backlight unit along the scanning direction of the liquid crystal display panel (i.e., the writing direction of the video data) to provide an effect similar to the impulsive driving of the CRT, Improves motion blurring.

The backlight unit is roughly divided into a direct type and an edge type. The direct-type backlight unit arranges a plurality of light sources on the lower surface of the diffusion plate to advance light to the back surface of the liquid crystal display panel. In contrast, the edge type backlight unit converts the optical or stray light incident from the light sources through the light guide plate into plane light, and advances the plane light converted through the optical sheets to the back surface of the liquid crystal display panel. A liquid crystal display device employing a direct-type backlight unit is disadvantageous in that it is difficult to slim down due to a gap that must be secured between the diffusion plate and the light sources, and the price is high. Accordingly, in recent years, liquid crystal display devices employing edge type backlight units have been intensively developed.

The edge type backlight unit includes a light guide plate, a plurality of light sources disposed to face the side surface of the light guide plate, and a plurality of optical sheets disposed between the liquid crystal display panel and the light guide plate. The edge type backlight unit is divided into a vertical edge type and a horizontal edge type according to the arrangement direction of the light sources. In the "vertical edge type", the light sources 3 are arranged along the vertical direction so as to face the left side and / or the right side of the light guide plate 2 as shown in FIG. In the 'horizontal edge type', as shown in FIG. 3, the light sources 3 are disposed along the horizontal direction so as to face the upper side and / or the lower side of the light guide plate 2.

In the "vertical edge type", the arrangement direction (vertical direction) of the light sources 3 is the same as the writing direction (vertical direction) of the video data, so that the application of the scanning backlight driving technique is easy. That is, in the 'vertical edge type', as shown in FIG. 1 and FIG. 2, based on the timing at which video data is written to a specific point SP # 1 in the first area AR1 of the liquid crystal display panel 1, Off timing of the second light source L2 is determined based on the timing at which video data is written to a specific point SP # 2 of the second area AR2 of the liquid crystal display panel 1, Off timing of the third light source L3 is determined and the on-off timing of the third light source L3 is determined based on the timing at which video data is written to a specific point SP # 3 of the third area AR3 of the liquid crystal display panel 1 Can be determined. The specific points (SP # 1, SP # 2, SP # 3) can be arbitrarily set as an optimization part for reducing the MPRT. As a result, the light sources L1 to L3 are sequentially flickered along the vertical direction along the data scanning direction of the liquid crystal display panel 1 (i.e., the writing direction of the video data), so that the backlight can be scanned up and down. However, when the 'vertical edge type' is employed, the left and / or right bezel of the liquid crystal display device is widened due to the light sources 3 disposed on the left side and / or the right side of the light guide plate 2.

In order to reduce the left and right bezels of a liquid crystal display device, it is necessary to adopt a "horizontal edge type". However, in the "horizontal edge type", since the arrangement direction (horizontal direction) of the light sources 3 is different from the writing direction (vertical direction) of the video data, the vertical scanning drive of the backlight is practically impossible. 3 and 4, when the backlight scanning drive of the backlight is applied to the " horizontal edge type ", all the light sources < RTI ID = 0.0 > The on-off timing of the transistors L1 to L4 can not be determined at the same time. This means that the MPRT is reduced only at a specific point SP # 1 of the liquid crystal display panel 1. The MPRT is not reduced at points other than the specific point SP # 1 of the liquid crystal display panel 1. As a result, in the 'horizontal edge type', the nine points of the liquid crystal display panel 1 P1 ~ P9) is degraded. Experiments have shown that MPRT uni - formity is around 60%. With this level of MPRT uniqueness, it is difficult to remove motion blurring.

As described above, the 'horizontal edge type' is a very advantageous method in many aspects, such as reduction in the thickness of the liquid crystal display device, reduction in the manufacturing cost, and reduction in the area of the right and left bezel, except that the backlight is not practically capable of scanning up and down . In order to remove the motion blurring while employing the "horizontal edge type", a new scheme is required instead of the vertical scanning drive of the backlight.

Accordingly, an object of the present invention is to provide a liquid crystal display device capable of removing motion blur while employing a backlight unit of a horizontal edge type.

According to an aspect of the present invention, there is provided a liquid crystal display device including: a liquid crystal display panel including a plurality of data lines and gate lines; A light guide plate disposed below the liquid crystal display panel and defining a first waveguide block and a second waveguide block adjacent to each other along a horizontal direction in which the gate lines extend; Light source arrays disposed on one side of the light guide plate along the horizontal direction to irradiate light to the wave guide blocks along a vertical direction in which the data lines are elongated; And timing of the light source of the light source array that emits light to the first waveguide block and the light source array that emits light to the second waveguide block are controlled differently based on the timing at which the video data is written into the liquid crystal display panel And a scanning backlight control unit.

The liquid crystal display device according to the present invention applies the left and right scanning drive of the backlight unlike the prior art, so that the motion blurring can be effectively removed while adopting the horizontal-edge type backlight unit. In addition, the MPRT uniqueness of the entire screen area can be greatly improved compared to the conventional one.

FIG. 1 and FIG. 2 are diagrams illustrating a vertical scanning driving operation of a backlight in a conventional liquid crystal display device employing a backlight unit of a 'vertical edge type'.
FIG. 3 and FIG. 4 are diagrams showing driving of a backlight in vertical scanning in a conventional liquid crystal display device employing a backlight unit of a 'horizontal edge type'.
5 is a view showing nine points for measuring MPRT unity in a liquid crystal display panel.
6 is a view illustrating a liquid crystal display device according to an embodiment of the present invention.
FIG. 7 is a view showing equivalently a part of a pixel array of the liquid crystal display panel shown in FIG. 6; FIG.
FIGS. 8A and 8B are views showing the arrangement positions of the light sources shown in FIG. 6. FIG.
FIGS. 9 to 11 are views showing an example of left and right scanning driving in which a scanning block is divided into two along a horizontal direction.
Figs. 12 to 14 are diagrams showing another example of the left-right scanning drive in which the scanning block is divided into two along the horizontal direction.
FIGS. 15 to 17 are diagrams showing another example of the left-right scanning drive in which the scanning block is divided into two along the horizontal direction.
Figs. 18 and 19 are views showing a display state according to a left-right scanning drive;
20 is a view showing optical waveforms at the time of driving the left-right scanning.
Figs. 21 to 23 are views showing MPRT measurements for nine points of the liquid crystal display panel according to the left-right scanning drive. Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 6 to 23. FIG. The 'horizontal direction' used in the following description indicates the direction in which the gate lines extend in the liquid crystal display panel and the 'vertical direction' indicates the direction in which the data lines extend in the liquid crystal display panel.

FIG. 6 shows a liquid crystal display according to an embodiment of the present invention, and FIG. 7 shows an equivalent part of a pixel array of the liquid crystal display panel shown in FIG. 8A and 8B show the arrangement positions of the light sources shown in FIG.

6 and 7, a liquid crystal display according to an embodiment of the present invention includes a liquid crystal display panel 10, a data driver 12 for driving the data lines 14 of the liquid crystal display panel 10, A gate driver 13 for driving the gate lines 15 of the liquid crystal display panel 10, a timing controller 11 for controlling the data driver 12 and the gate driver 13, A scanning backlight control unit 16 for controlling the scanning driving of the light sources 20B of the backlight unit 20 and a light source 20B of the backlight unit 20 for driving the backlight unit 20, And a light source driver 17 for the light source.

In the liquid crystal display panel 10, a liquid crystal layer is formed between two glass substrates. A plurality of data lines 14a to 14d and a plurality of gate lines 15a to 15d are crossed on the lower glass substrate of the liquid crystal display panel 10 as shown in FIG. The liquid crystal cells Clc are arranged in a matrix form in the liquid crystal display panel 10 by the intersection structure of the data lines 14a to 14d and the gate lines 15a to 15d. A thin film transistor (TFT), a pixel electrode 1 of a liquid crystal cell Clc connected to a thin film transistor (TFT), a storage capacitor Cst, and the like are formed on the lower glass substrate of the liquid crystal display panel 10. The liquid crystal cells Clc arranged adjacent to each other in the horizontal direction form a horizontal pixel line.

A black matrix, a color filter, and a common electrode 2 are formed on the upper glass substrate of the liquid crystal display panel 10 as shown in Fig. The common electrode 2 is formed on an upper glass substrate in a vertical electric field driving mode such as a TN (Twisted Nematic) mode and a VA (Vertical Alignment) mode. The common electrode 2 is formed of an IPS (In Plane Switching) mode, an FFS (Fringe Field Switching) Is formed on the lower glass substrate together with the pixel electrode 1 in the same horizontal electric field driving system. On the upper glass substrate and the lower glass substrate of the liquid crystal display panel 10, a polarizing plate is attached and an alignment film for forming a pre-tilt angle of the liquid crystal is formed on the inner surface in contact with the liquid crystal.

The data driver 12 includes a shift register for sampling a clock signal, a register for temporarily storing digital video data (RGB), a data register for storing data for one line in response to a clock signal from a shift register, A digital / analog converter for selecting the positive / negative gamma voltage under reference to the gamma reference voltage corresponding to the digital data value from the latch, the positive / negative gamma voltage converted by the positive / negative gamma voltage A multiplexer for selecting the data line 14 to which analog data is supplied, and an output buffer connected between the multiplexer and the data line 14, and the like. The data driver 12 latches the digital video data RGB under the control of the timing controller 11 and outputs the latched digital video data RGB to the positive polarity / Polarity analog data voltages and supplies them to the data lines 14. [

The gate driver 13 is composed of a plurality of gate driver ICs each including a shift register, a level shifter for converting an output signal of the shift register into a swing width appropriate for TFT driving of the liquid crystal cell, and an output buffer. The gate driver 13 sequentially outputs gate pulses (or scan pulses) having a pulse width of approximately one horizontal period under the control of the timing controller 11 and supplies them to the gate lines 15.

The timing controller 11 receives digital video data RGB from an external system board (not shown) and supplies the digital video data RGB to the data driver 12. The timing controller 11 receives timing signals Vsync, Hsync, DE and DCLK from the system board and controls the data driver 12 and the gate 13 based on the timing signals Vsync, Hsync, DE and DCLK. And generates timing control signals DDC and GDC for controlling the operation timing of the driving unit 13. [ The timing controller 11 inserts an interpolation frame between the frames of the input video signal input at a frame frequency of 60 Hz and multiplies the data timing control signal DDC and the gate timing control signal GDC to 60 x N It is possible to control the operations of the data driver 12 and the gate driver 13 at a frame frequency of Hz.

The backlight unit 20 includes a light guide plate 20A, a plurality of light sources 20B disposed so as to face the side surface of the light guide plate 20A and a plurality of light sources 20B disposed between the liquid crystal display panel 10 and the light guide plate 20A. And is implemented in an edge form including sheets (not shown). The backlight unit 20 is implemented as a 'horizontal edge type' among the edge types.

The light sources 20B may be disposed along the horizontal direction so as to face the upper side of the light guide plate 20A as shown in Fig. 8A, or along the horizontal direction as opposed to the lower side of the light guide plate 20A as shown in Fig. 8B . 8A, the light irradiation direction of the light sources 20B is the same as the direction in which the video data is written. 8B, the light irradiation direction of the light sources 20B is opposite to the direction in which the video data is written. The light sources 20B include point light sources such as a light emitting diode (LED).

The light sources 20B constitute at least two or more light source arrays. Each light source array includes at least two light sources 20B. The light guide plate 20A defines at least two waveguide blocks adjacent to each other along the horizontal direction corresponding to the light source array. For example, when the light source array is composed of two, the light guide plate 20A defines two wave guide blocks.

The scanning backlight control unit 16 sequentially drives the light source arrays along the horizontal direction orthogonal to the data scanning direction of the liquid crystal display panel 10 (that is, the writing direction of the video data, vertical direction) under the control of the timing control unit 11 The light sources are controlled by Pulse Width Modulation (PWM). The scanning backlight control unit 16 implements left and right scanning driving of the backlight by controlling the light source arrays to sequentially flash along the horizontal direction. To this end, the scanning backlight control unit 16 controls the light source array that irradiates light to the first waveguide block and the light source array that irradiates light to the second waveguide block, based on the timing at which the video data is written into the liquid crystal display panel 10 A light source control signal Lsync for controlling the light source sink timing of the light source array to be different from each other is generated and the operation of the light source driver 17 is controlled by the light source control signal Lsync. The scanning backlight control unit 16 may be located outside the timing control unit 11 or may be embedded in the timing control unit 11. [

The light source driver 17 interrupts the driving current applied to the light sources 20B under the control of the scanning backlight controller 16 to sequentially drive the light sources 20B on an array basis.

FIGS. 9 to 11 show an example of left and right scanning driving in which the scanning block is divided into two along the horizontal direction.

Referring to FIG. 9, the light sources L1 to L6 and 20B are disposed along the horizontal direction so as to face the upper side of the light guide plate 20A so as to emit light in the same direction as the video data writing direction. The light sources L1 to L6 and 20B include a first light source array LA # 1 and a second light source array LA # 2 which are flickered at different timings.

The light sources L1 to L3 belonging to the first light source array LA # 1 are opposed to the upper left side of the light guide plate 20A. The light guide plate 20A defines a first waveguide block BL1 corresponding to the first light source array LA # 1. The first light source array LA # 1 and the first waveguide block BL1 define a first scanning block.

The light sources L4 to L6 belonging to the second light source array LA # 2 are opposed to the upper right side of the light guide plate 20A. The light guide plate 20A defines a second waveguide block BL2 corresponding to the second light source array LA # 2. The second light source array LA # 2 and the second waveguide block BL2 define a second scanning block.

The scanning backlight control unit controls the ON-state of the first light source array LA # 1 based on the timing at which video data is written in the first area AR1 of the liquid crystal display panel 10 corresponding to the first waveguide block BL1. Off timing based on the timing at which the video data is written in the second area AR2 of the liquid crystal display panel 10 corresponding to the second waveguide block BL2, The second light source sink timing for controlling the on-off timing of the light source array LA # 2 is determined. The first area AR1 and the second area AR2 are separated from the liquid crystal display panel 10 when the liquid crystal display panel 10 is divided into the upper part UP, the middle part MP and the lower part DP along the vertical direction. (MP). The first light source sync timing and the second light source sync timing are different from each other as shown in Fig.

Under the control of the scanning backlight control unit, as shown in Fig. 10, the first light source array LA # 1 is switched from the time t1 at which video data is written to the first horizontal pixel line HL # 1 of the liquid crystal display panel 10 Is turned off during the first period TP1 indicating the time t2 at which the video data is written to the second horizontal pixel line HL # 2 of the liquid crystal display panel 10 and the first period TP1 ) Is turned on for the remaining period. 10, the second light source array LA # 2 is connected to the liquid crystal display panel 10 from the time t3 at which video data is written in the third horizontal pixel line HL # 3 of the liquid crystal display panel 10, Is turned off during the second period TP2 indicating the time t4 at which the video data is written to the fourth horizontal pixel line HL # 4 of the first horizontal pixel line HL # 4, and during the remaining period except for the second period TP2 in one frame Is turned on.

The time t1 at which the video data is written to the first horizontal pixel line HL # 1 is faster than the time t3 at which the video data is written to the third horizontal pixel line HL # 3. The first period TP1 and the second period TP2 partially overlap each other, and the temporal lengths of them TP1 and TP2 are equal to each other.

11, the light sources L1 to L6 and 20B may be disposed along the horizontal direction so as to face the lower side of the light guide plate 20A so as to irradiate light in a direction opposite to the video data writing direction. The driving for this is substantially the same as that described in Figs. 9 and 10. Fig.

As described above, in this embodiment, the timing of the light source sync of the scanning blocks is made different based on the timing at which the video data is written in the middle part (MP) of the liquid crystal display panel. According to this embodiment, since the MPRT is greatly reduced in the middle portion MP of the liquid crystal display panel, the effect of suppressing motion blurring in the middle portion MP of the liquid crystal display panel is large. This embodiment is advantageous for improving moving image display quality in consideration of the fact that a significant portion of the image is mainly allocated to the middle portion (MP) of the liquid crystal display panel when moving images are displayed.

12 to 14 show another example of the left-right scanning drive in which the scanning block is divided into two along the horizontal direction.

Referring to FIG. 12, the light sources L1 to L6 and 20B are disposed along the horizontal direction so as to face the upper side of the light guide plate 20A so as to irradiate light in the same direction as the video data writing direction. The light sources L1 to L6 and 20B include a first light source array LA # 1 and a second light source array LA # 2 which are flickered at different timings.

The light sources L1 to L3 belonging to the first light source array LA # 1 are opposed to the upper left side of the light guide plate 20A. The light guide plate 20A defines a first waveguide block BL1 corresponding to the first light source array LA # 1. The first light source array LA # 1 and the first waveguide block BL1 define a first scanning block.

The light sources L4 to L6 belonging to the second light source array LA # 2 are opposed to the upper right side of the light guide plate 20A. The light guide plate 20A defines a second waveguide block BL2 corresponding to the second light source array LA # 2. The second light source array LA # 2 and the second waveguide block BL2 define a second scanning block.

The scanning backlight control unit controls the ON-state of the first light source array LA # 1 based on the timing at which video data is written in the first area AR1 of the liquid crystal display panel 10 corresponding to the first waveguide block BL1. Off timing based on the timing at which the video data is written in the second area AR2 of the liquid crystal display panel 10 corresponding to the second waveguide block BL2, The second light source sink timing for controlling the on-off timing of the light source array LA # 2 is determined. The first area AR1 and the second area AR2 are separated from the liquid crystal display panel 10 when the liquid crystal display panel 10 is divided into the upper part UP, the middle part MP and the lower part DP along the vertical direction. As shown in FIG. The first light source sync timing and the second light source sync timing are different from each other as shown in Fig.

13, the first light source array LA # 1 is switched from the time t1 at which the video data is written to the first horizontal pixel line HL # 1 of the liquid crystal display panel 10 to the first horizontal pixel line HL # 1 under the control of the scanning backlight control unit Is turned off during the first period TP1 indicating the time t2 at which the video data is written to the second horizontal pixel line HL # 2 of the liquid crystal display panel 10 and the first period TP1 ) Is turned on for the remaining period. 13, the second light source array LA # 2 is connected to the liquid crystal display panel 10 from the time t3 at which video data is written in the third horizontal pixel line HL # 3 of the liquid crystal display panel 10, Is turned off during the second period TP2 indicating the time t4 at which the video data is written to the fourth horizontal pixel line HL # 4 of the first horizontal pixel line HL # 4, and during the remaining period except for the second period TP2 in one frame Is turned on.

The time t1 at which the video data is written to the first horizontal pixel line HL # 1 is faster than the time t3 at which the video data is written to the third horizontal pixel line HL # 3. The first period TP1 and the second period TP2 partially overlap each other, and the temporal lengths of them TP1 and TP2 are equal to each other.

14, the light sources L1 to L6 and 20B may be disposed along the horizontal direction so as to face the lower side of the light guide plate 20A so as to irradiate light in a direction opposite to the video data writing direction. The driving for this is substantially the same as that described in Figs. 12 and 13. Fig.

As described above, in this embodiment, the light source sync timing of the scanning blocks are made different based on the timing at which the video data is written in the lower portion DP of the liquid crystal display panel. According to this embodiment, since the MPRT is greatly reduced in the lower portion DP of the liquid crystal display panel, the effect of suppressing motion blurring in the lower portion DP of the liquid crystal display panel is large. Considering that subtitles are mainly allocated to the lower portion (DP) of the liquid crystal display panel during image display including subtitles, this embodiment is advantageous for improving the display quality of subtitle images.

15 to 17 show another example of the left-right scanning drive in which the scanning block is divided into two along the horizontal direction.

Referring to FIG. 15, the light sources L1 to L6 and 20B are disposed along the horizontal direction so as to face the upper side of the light guide plate 20A so as to emit light in the same direction as the video data writing direction. The light sources L1 to L6 and 20B include a first light source array LA # 1, a second light source array LA # 2 and a third light source array LA # 3. The first and third light source arrays LA # 1 and LA # 3 are flashed at the same timing with each other and the second light source array LA # 2 is composed of the first and third light source arrays LA # 1 and LA # And is flickered at a different timing.

The light sources L1 and L2 belonging to the first light source array LA # 1 are opposed to the upper left side of the light guide plate 20A and the light sources L5 and L6 belonging to the third light source array LA # And faces the upper right side of the light guide plate 20A. The light guide plate 20A defines the first-first waveguide block BL1-1 corresponding to the first light source array LA # 1 and the first-first waveguide block BL1-1 corresponding to the second light source array LA # (BL1-2). The first light source array LA # 1, the first waveguide block BL1, the second light source array LA # 3 and the first and second waveguide blocks BL1-2 define a first scanning block.

The light sources L3 and L4 belonging to the second light source array LA # 2 are opposed to the intermediate upper side of the light guide plate 20A. The light guide plate 20A defines a second waveguide block BL2 corresponding to the second light source array LA # 2. The second light source array LA # 2 and the second waveguide block BL2 define a second scanning block.

The scanning backlight control unit controls the first light source array LA # 1 based on the timing at which the video data is written into the first area AR1 of the liquid crystal display panel 10 corresponding to the first- And the video data is written in the second area AR2 of the liquid crystal display panel 10 corresponding to the second waveguide block BL2 Determines timing of the second light source for controlling the on-off timing of the second light source array (LA # 2) based on the timing, and determines the second light source timing to control the liquid crystal display panel 10 ) Timing of the third light source array (LA # 3) based on the timing at which the video data is written in the first area (AR1) of the first light source array (LA # 3). The first area AR1 is located in the lower portion DP of the liquid crystal display panel 10 when the liquid crystal display panel 10 is divided into the upper part UP, the middle part MP and the lower part DP along the vertical direction And the second area AR2 are located in the middle part MP of the liquid crystal display panel 10. [ The first-first light source sync timing and the first-second light source sync timing are the same as shown in Fig. In addition, the second light source sync timing differs from that of the 1-1 and 1-2 light source sync timings as shown in Fig.

16, the first and third light source arrays LA # 1 and LA # 3 transmit video data to the first horizontal pixel line HL # 1 of the liquid crystal display panel 10 under the control of the scanning backlight control unit Is turned off during the first period TP1 that indicates from the writing time t1 to the time t2 when the video data is written to the second horizontal pixel line HL # 2 of the liquid crystal display panel 10, In the first period TP1 except for the first period TP1. 16, the second light source array LA # 2 is connected to the liquid crystal display panel 10 from the time t3 at which video data is written in the third horizontal pixel line HL # 3 of the liquid crystal display panel 10, Is turned off during the second period TP2 indicating the time t4 at which the video data is written to the fourth horizontal pixel line HL # 4 of the first horizontal pixel line HL # 4, and during the remaining period except for the second period TP2 in one frame Is turned on.

The time t1 at which the video data is written to the first horizontal pixel line HL # 1 is later than the time t3 at which the video data is written to the third horizontal pixel line HL # 3. The first period TP1 and the second period TP2 are not overlapped with each other, and the temporal lengths of them TP1 and TP2 are equal to each other.

17, the light sources L1 to L6 and 20B may be disposed along the horizontal direction so as to face the lower side of the light guide plate 20A so as to irradiate light in a direction opposite to the video data writing direction. The driving for this is substantially the same as that described in Figs. 15 and 16. Fig.

As described above, in this embodiment, the light source sync timing of the scanning blocks is made different based on the timing at which the video data is written in the middle part (MP) and the lower part (DP) of the liquid crystal display panel. According to this embodiment, since the MPRT is greatly reduced in the middle portion MP and the lower portion DP of the liquid crystal display panel, the effect of suppressing motion blurring in the middle portion MP and the lower portion DP of the liquid crystal display panel is large . This embodiment is advantageous in improving the display quality of moving pictures and subtitle images.

Figs. 18 and 19 show display states according to the left and right scanning driving. 20 shows optical waveforms at the time of driving the left and right scanning.

Fig. 18 relates to the left and right scanning driving described with reference to Figs. 9 to 14. Fig. 18 shows that the image quality of the video data is increased to 240 Hz by the backlight blinking at 240 Hz by the left and right scanning drive even when the video data is written to the liquid crystal display panel at 120 Hz. This is because the optical waveform at the time of driving the left and right scanning is 180 degrees out of phase between the scanning blocks as shown in FIG.

Fig. 19 relates to the left and right scanning driving described with reference to Figs. 15 to 17. Fig. 19 shows that the image quality of the video data is increased to 240 Hz by the backlight blinking at 240 Hz by the left and right scanning drive even when the video data is written to the liquid crystal display panel at 120 Hz. This is because the optical waveform at the time of driving the left and right scanning is 180 degrees out of phase between the scanning blocks as shown in FIG.

Figs. 21 to 23 are diagrams showing MPRT measurements for nine points (corresponding to P1 to P9 in Fig. 5) of the liquid crystal display panel according to the left-right scanning drive.

Fig. 21 shows MPRT measurements for nine points of the liquid crystal display panel according to the first embodiment (corresponding to Figs. 9 to 11). FIG. 21 shows the relative ratios of MPRT measurements at the remaining points P1 to P8 when the ratio of the point at which the MPRT measurement value is highest (P9) is taken as 100%. In particular, it can be seen that the MPRT is significantly reduced in the middle part MP of the liquid crystal display panel. In the LCD panel, MPRT uniqueness of the entire screen is about 85%, which is much better than the conventional 60%.

Fig. 22 shows MPRT measurements for nine points of the liquid crystal display panel according to the second embodiment (corresponding to Figs. 12 to 14). 22 shows the relative ratios of the MPRT measurements at the remaining points P1, P2 and P4 to P9 when the ratio of the point P3 at which the MPRT measurement value is the highest is 100%. According to this, it can be seen that MPRT is significantly reduced especially in the lower portion (LP) of the liquid crystal display panel. In the LCD panel, MPRT uniqueness of the entire screen is about 85%, which is much better than the conventional 60%.

Fig. 23 shows MPRT measurements for nine points of the liquid crystal display panel according to the third embodiment (corresponding to Figs. 15 to 17). 23 shows the relative ratios of the MPRT measurements at the remaining points P1, P2, and P4 to P9 when the ratio of the point at which the MPRT measurement is highest (P3) is taken as 100%. In particular, it can be seen that MPRT is significantly reduced in the middle part (MP) and the lower part (LP) of the liquid crystal display panel. In the LCD panel, MPRT uniqueness of the entire screen is about 85%, which is much better than the conventional 60%.

As described above, the liquid crystal display device according to the present invention applies the left and right scanning drive of the backlight unlike the prior art, so that the motion blurring can be effectively removed while adopting the horizontal-edge type backlight unit. In addition, the MPRT uniqueness of the entire screen area can be greatly improved compared to the conventional one.

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. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

10: liquid crystal display panel 11: timing controller
12: Data driver 13: Gate driver
16: Scanning backlight control unit 17: Light source driver
20: backlight unit 20A: light guide plate
20B: Light sources

Claims (13)

A liquid crystal display panel in which a plurality of data lines and gate lines are formed;
A light guide plate disposed below the liquid crystal display panel and defining a first waveguide block and a second waveguide block adjacent to each other along a horizontal direction in which the gate lines extend;
Light source arrays disposed on one side of the light guide plate along the horizontal direction to irradiate light to the wave guide blocks along a vertical direction in which the data lines are elongated; And
A first light source sync timing of the first light source array for emitting light to the first waveguide block and a second light source sync timing of the first light source array for emitting light to the first waveguide block based on a timing at which video data is written in the middle, And a scanning backlight control unit for controlling the second light source sink timing of the second light source array which irradiates light to the two waveguide blocks differently from each other. The method according to claim 1,
Wherein the first light source array and the second light source array are flickered at different timings. 3. The method of claim 2,
The scanning backlight control unit includes:
Off timing of the first light source array on the basis of a timing at which the video data is written in a first area in an intermediate portion or a lower portion of the liquid crystal display panel corresponding to the first waveguide block, Off timing of the second light source array based on the timing at which the video data is written in the second region or the lower region of the liquid crystal display panel corresponding to the block. The method of claim 3,
Wherein the first light source array includes a first light source array for supplying a first horizontal pixel line to a first horizontal pixel line of the liquid crystal display panel during a first period of time from a time at which video data is written to a first horizontal pixel line of the liquid crystal display panel to a time at which video data is written into the second horizontal pixel line And is turned on during the remaining period within the one frame except for the first period;
Wherein the second light source array includes a second light source array for supplying a first horizontal pixel line to a first horizontal pixel line of the liquid crystal display panel during a second period of time from a time when video data is written to a third horizontal pixel line of the liquid crystal display panel to a time point at which video data is written to the fourth horizontal pixel line And is turned on during the remaining period except for the second period within one frame. 5. The method of claim 4,
Wherein the first period and the second period are partially overlapped with each other, and the first and second periods have the same temporal length. delete delete The method according to claim 1,
The first light source array irradiates light to a first-first waveguide block included in the first waveguide block, the second light source array irradiates light to the second waveguide block,
The light source array further includes a third light source array for emitting light to the first and second waveguide blocks included in the first waveguide block,
Wherein the first and third light source arrays are flashed at the same timing with each other, and the second light source array is flickered at a different timing compared to the first and third light source arrays. 9. The method of claim 8,
The scanning backlight control unit includes:
Off timing of the first light source array on the basis of the timing at which the video data is written in the first area below the liquid crystal display panel corresponding to the first-first waveguide block, Off timing of the second light source array on the basis of the timing at which the video data is written in the second area of the middle part of the liquid crystal display panel corresponding to the first- Off timing of the third light source array based on a timing at which the video data is written in the first area under the display panel. 10. The method of claim 9,
Wherein the first and third light source arrays are arranged in a matrix form such that the video data is written in the first horizontal pixel line of the liquid crystal display panel from the time when the video data is written to the second horizontal pixel line of the liquid crystal display panel 1, and is turned on during the remaining period except for the first period within one frame;
Wherein the second light source array includes a second light source array for supplying a first horizontal pixel line to a first horizontal pixel line of the liquid crystal display panel during a second period of time from a time when video data is written to a third horizontal pixel line of the liquid crystal display panel to a time point at which video data is written to the fourth horizontal pixel line And is turned on during the remaining period except for the second period within one frame. 11. The method of claim 10,
Wherein the first period and the second period are non-overlapping with each other, and the first and second periods have the same temporal length. delete The method according to claim 1,
Wherein the light source arrays irradiate light to the wave guide blocks in the same or opposite direction as the direction in which the video data is written.

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