KR102340302B1 - Liquid crystal display apparatus - Google Patents

Abstract

A liquid crystal display is provided. The liquid crystal display includes sub-pixels configured to be driven by a gate signal applied to a gate line from the gate driver and a data signal applied from the data driver to the data line, and gamma reference voltages configured to supply gamma reference voltages expressing grayscale to the data driver. The voltage generator, the power supply configured to supply the first VDD signal to the gamma voltage generator, and the second VDD signal to the data driver, and the power supply and the gamma voltage generator are arranged between the adjacent sub-pixels and a crosstalk compensator configured to filter the voltage of the first VDD signal so that the level of crosstalk therebetween is reduced.

Description

Liquid crystal display device {LIQUID CRYSTAL DISPLAY APPARATUS}

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of reducing a crosstalk problem occurring in a liquid crystal display device.

BACKGROUND ART As we enter the information age in earnest, the field of display devices for visually displaying electrical information signals is rapidly developing. Accordingly, research to develop performance such as reduction in thickness, weight reduction, and low power consumption for various display devices is continuing. Representative examples of such a display device include a plasma display panel device (PDP), a field emission display device (FED), an electro-wetting display device (EWD), and an organic light emitting display device. There are an organic light emitting display device (OLED) and a liquid crystal display device (LCD).

Since the liquid crystal display device can be manufactured to be lightweight and thin, and has excellent advantages in terms of power consumption, color gamut, resolution, and viewing angle, it is widely adopted in various electronic products.

Such a liquid crystal display has a crosstalk problem, which is vulnerable to a pattern of a specific image. In particular, since crosstalk of the liquid crystal display tends to become more severe as the resolution increases, there is a problem in that the level of crosstalk of the liquid crystal display of high resolution increases.

Conventionally, in order to solve the above-mentioned problem, a method of compensating for the specific crosstalk by recognizing a specific crosstalk pattern of the liquid crystal display device and selectively applying an algorithm stored in the memory according to the recognized crosstalk pattern has been used.

In addition, in order to solve the above-described problem, a method of lowering the resistance of the common electrode is also used in the prior art to compensate for distortion of the common voltage Vcom of the liquid crystal display.

In addition, in order to solve the above-described problem, a method of applying a common voltage (Vcom) compensation circuit to the common voltage (Vcom) supply circuit is used in order to sufficiently discharge the capacitance charged in the liquid crystal layer of the liquid crystal display device. became In particular, this method was used for the line-inversion method.

In addition, in order to solve the above-described problem, various methods for compensating the common voltage Vcom, such as a dot-inversion method, have been used in the prior art so that the common voltage Vcom is maximally stabilized.

[Related technical literature]

1. Liquid crystal display device and its driving method (Korean Patent Application No. 10-2007-0053629)

Horizontal crosstalk is a chronic problem of liquid crystal displays, and the problem of horizontal crosstalk has not yet been fundamentally solved. In particular, conventionally, it has been recognized that the cause of horizontal crosstalk is that the common voltage Vcom of the common electrode of the liquid crystal display is shaken when the liquid crystal display displays a specific pattern.

The inventors of the present invention have made various studies to solve the chronic horizontal crosstalk problem of the liquid crystal display. In particular, the inventors of the present invention have recognized that the cause of horizontal crosstalk is that when the amount of current required for the liquid crystal display changes rapidly as well as the unstable common voltage, a problem occurs in the power supply of the driving circuit unit.

In particular, when the gamma voltage generator that generates the gamma voltage receives the VDD signal from the power supply, when a specific pattern image that can generate horizontal crosstalk is displayed, the current amount of the VDD signal rapidly decreases. recognized.

Accordingly, the problem to be solved by the present invention is to independently configure the VDD wiring supplied to the gamma voltage generator and the data driver, and include a horizontal crosstalk compensator that can reduce the fluctuation of the VDD signal input to the gamma voltage generator. It is to provide a novel liquid crystal display including

Another object of the present invention is to provide a novel liquid crystal display device in which horizontal crosstalk can be generated gently so that horizontal crosstalk is not easily recognized by a viewer when horizontal crosstalk occurs.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above problems, a liquid crystal display according to an exemplary embodiment of the present invention provides sub-pixels configured to be driven by a gate signal applied to a gate line from a gate driver and a data signal applied from a data driver to a data line. a gamma voltage generator configured to supply gamma reference voltages representing grayscale to the data driver, a power supply configured to supply a first VDD signal to the gamma voltage generator, and a second VDD signal configured to supply a second VDD signal to the data driver; and a crosstalk compensator disposed between the power supply unit and the gamma voltage generator, configured to filter the voltage of the first VDD signal so that a level of crosstalk between adjacent sub-pixels is reduced.

According to another aspect of the present invention, in the liquid crystal display device, a power supply unit, a crosstalk compensator, and a gamma voltage generator are disposed, and a first VDD line for supplying a first VDD signal from the power supply unit to the gamma voltage generation unit and a power supply unit The circuit board may further include a circuit board on which a second VDD line for supplying a second VDD signal to the data driver is formed.

According to another feature of the present invention, the crosstalk compensator is configured to filter the high frequency component of the first VDD signal transmitted from the power supply unit through the first VDD line.

According to another feature of the present invention, the crosstalk compensator includes at least a first resistor, a second resistor, and a first capacitor, and one end of the first resistor is connected to the first VDD wire, and the other end of the first resistor is the second resistor. One end of the second resistor and one end of the first capacitor are connected, and the other end of the second resistor and the other end of the first capacitor are configured to be grounded.

According to another feature of the present invention, the crosstalk compensator further includes a buffer configured to compensate the output voltage of the first VDD signal reduced by the crosstalk compensator.

According to another feature of the present invention, the resistance value of the first resistor is configured to be less than the resistance value of the second resistor.

In order to solve the above problems, a driving circuit board according to an embodiment of the present invention includes a power supply configured to supply a VDD signal, a first VDD wire configured to transmit a VDD signal to a gamma voltage generator, and a VDD signal to data a second VDD wiring configured to transmit to the driver; and a horizontal crosstalk compensator disposed on the first VDD wiring and configured to filter a high frequency component of the VDD signal transmitted to the gamma voltage generator.

According to another aspect of the present invention, the driving circuit board is configured to supply a gamma voltage at which horizontal crosstalk is gradually generated to the liquid crystal panel by a horizontal crosstalk compensator.

The present invention provides a horizontal crosstalk compensator capable of independently configuring the VDD wiring supplied to the gamma voltage generator and the data driver and reducing fluctuation of the VDD signal input to the gamma voltage generator, thereby charging the liquid crystal display. There is an effect that can reduce the horizontal crosstalk that is generated when the amount of electric power is rapidly changed.

According to the present invention, the horizontal crosstalk is generated gently, so that when the horizontal crosstalk occurs, the horizontal crosstalk is not easily recognized by the viewer.

The effect according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a conceptual diagram schematically illustrating a liquid crystal display according to an embodiment of the present invention.
2 is a conceptual diagram schematically illustrating a horizontal crosstalk compensator of a liquid crystal display according to an exemplary embodiment of the present invention.
3 is a conceptual diagram schematically illustrating a horizontal crosstalk compensator of a liquid crystal display according to another exemplary embodiment of the present invention.
4A is an exemplary image pattern used when examining horizontal crosstalk of a liquid crystal display.
4B is a schematic conceptual diagram illustrating a horizontal crosstalk phenomenon that occurs when the exemplary image pattern of FIG. 4A is displayed on a liquid crystal display of a comparative example.
FIG. 4C is a schematic conceptual diagram illustrating horizontal crosstalk compensation that is generated when the exemplary image pattern of FIG. 4A is displayed on a liquid crystal display according to an embodiment of the present invention.
4D is a schematic waveform diagram comparing an output of a gamma voltage generator corresponding to sub-pixels of a data line of FIGS. 4B and 4C to a comparative example and an exemplary embodiment of the present invention.
5A is a conceptual diagram schematically illustrating a liquid crystal display according to another exemplary embodiment of the present invention.
FIG. 5B is a conceptual diagram schematically illustrating the gamma voltage generator of FIG. 5A .

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative and the present invention is not limited to the illustrated matters. Like reference numerals refer to like elements throughout. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, cases including the plural are included unless otherwise explicitly stated.

In interpreting the components, it is construed as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between two parts unless 'directly' is used.

Reference to a device or layer “on” another device or layer includes any intervening layer or other device directly on or in the middle of the other device or layer.

Although first, second, etc. are used to describe various elements, these elements are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the spirit of the present invention.

Like reference numerals refer to like elements throughout.

The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present invention is not necessarily limited to the size and thickness of the illustrated component.

Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, and as those skilled in the art will fully understand, technically various interlocking and driving are possible, and each embodiment may be implemented independently of each other, It may be possible to implement together in a related relationship.

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

1 is a conceptual diagram schematically illustrating a liquid crystal display according to an exemplary embodiment of the present invention. The liquid crystal display 100 according to an embodiment of the present invention includes a liquid crystal panel 104 and a driving circuit board 140 .

The liquid crystal panel 104 will be schematically described with reference to FIG. 1 . The liquid crystal panel 104 is a passive device that does not emit light by itself.

The liquid crystal panel 104 includes at least a first polarizing film, a first substrate, a liquid crystal layer, a second substrate, and a second polarizing film.

The liquid crystal panel 104 may be divided into a pixel area AA and a peripheral area PA. A sub-pixel PXL is disposed in the pixel area AA to display an image. The peripheral area PA is configured to surround the pixel area AA. Various circuits and wirings necessary for driving each sub-pixel PXL of the pixel area AA are disposed in the peripheral area PA. In the present specification, the sub-pixel PXL refers to an area capable of displaying an image in the smallest unit in the pixel area AA of the liquid crystal display 100 .

At least a plurality of gate lines 130 , a plurality of data lines 132 , and a plurality of sub-pixels PXL are disposed in the pixel area AA on the first substrate. The gate wiring 130 may be configured to extend in the first direction of the pixel area AA. The data line 132 may be configured to extend in the second direction of the pixel area AA.

The light transmittance (%) of the sub-pixel PXL is adjusted according to the intensity of the image signal of the image input from the data driver 144 .

The first polarizing film is disposed on the rear surface of the first substrate, and performs a function of polarizing light incident on the first substrate from the light source unit. The second polarizing film is disposed on the upper surface of the second substrate to polarize the light transmitted through the second substrate.

The gate driver 142 and the flexible circuit board 136 are disposed in the peripheral area PA of the first substrate. A data driver 144 is disposed on the flexible circuit board 136 . The flexible circuit board 136 connects the liquid crystal panel 104 and the driving circuit board 140 . A color filter is disposed on the second substrate. That is, the first substrate may be defined as an array substrate, and the second substrate may be defined as a color filter substrate.

The gate driver 142 applies a control signal to the plurality of gate lines 130 to activate the sub-pixel PXL in the pixel area AA.

The gate driver 142 is configured to be disposed on at least one side surface of the peripheral area PA of the liquid crystal display 100 . The gate driver 142 is configured to receive various control signals from the data driver 144 and control the liquid crystal panel 104 to display an image in the pixel area AA of the liquid crystal panel 104 . The gate driver 142 is configured to be connected to the plurality of gate wirings 130 .

The gate driver 142 is configured as a gate-driver in panel with a built-in panel type. The gate driver 142 may be configured as a semiconductor chip having a predetermined number of channels, and may be configured to be mounted on the peripheral area PA of the first substrate in the form of a chip on film (COF) or a chip on glass (COG). .

The flexible circuit board 136 is configured to receive a digital image signal and transmit it to the data driver 144 . The flexible circuit board 136 may be bonded to the liquid crystal panel 104 and the driving circuit board 160 by an anisotropic conductive film (ACF).

The data driver 144 is configured to be electrically connected to the sub-pixels PXL through the data lines 132 to apply an image signal to the pixel area AA. The data driver 144 receives the gamma voltage from the gamma voltage generator 170 and converts the digital image signal into an analog voltage.

The data driver 144 is configured to control the gate driver 142 . In order to perform the above-described function, the data driver 144 may be electrically connected to the gate driver 142 . However, the present invention is not limited thereto, and the gate driver 142 may be directly controlled from the controller 146 .

Referring again to FIG. 1 , the driving circuit board 140 will be described. The driving circuit board 160 includes at least a first VDD line 192 , a second VDD line 194 , a gamma voltage line 196 , a control unit 146 , a power supply unit 150 , a gamma voltage generation unit 170 , and a horizontal crosstalk compensator 190 . The width and number of wirings illustrated in FIG. 1 are schematic for convenience of description, and are not limited thereto. For example, the gamma voltage line 196 may include 16 lines to supply 16 reference voltages.

The controller 146 controls the time interval and frequency period of the image signal and the control signals so that the input digital image signal can be applied to the sub-pixels PXL in the pixel area AA. That is, the controller 146 performs a function of a timing controller that adjusts the timing of the image signal so that the image is displayed in the pixel area AA of the liquid crystal panel 104 . In other words, the controller 146 transmits the aligned image signal in a digital format to the data driver 144 .

The power supply 150 generates various signals necessary for the liquid crystal display 100 to operate. Typically, the power supply 150 generates a VDD signal. The VDD signal is a main signal used for the gamma voltage generator 170 and the data driver 144 . The VDD signal generated by the power supply 150 is configured to supply a predetermined voltage and current to the gamma voltage generator 170 and the data driver 144 . In particular, since the gamma voltage is generated based on the VDD signal, when the voltage of the VDD signal is shaken, the gamma voltage generated by the gamma voltage generator 170 is shaken. Accordingly, the image quality of the liquid crystal display 100 expressing grayscale based on the gamma voltage is deteriorated. In addition, the power supply 150 may generate a gate high voltage VGH and a gate low voltage VGL and supply them to the gate driver 142 .

Specifically with respect to the power supply unit 150, the power supply unit 150 is configured to supply DC power. For example, the power supply 150 may be a buck, a boost, a DC-DC converter, a switching regulator, or the like. However, the present invention is not limited thereto. The power supply unit 150 is configured as a feedback system, and controls the voltage of the VDD signal in real time to be constant. That is, when the voltage value of the output VDD signal becomes higher than the voltage of the preset VDD signal at a high speed, the feedback system of the power supply unit 150 lowers the voltage of the output VDD signal, and the voltage value is higher than the voltage of the preset VDD signal. When low, the feedback system of the power supply 150 increases the voltage of the output VDD signal. Accordingly, the voltage of the output VDD signal may include, for example, a ripple having a predetermined amplitude based on the voltage of the set VDD signal.

The power supply unit 150 is configured to be connected to the gamma voltage generation unit 170 through the first VDD line 192 .

The first VDD wiring 192 is a dedicated signal supply wiring configured to supply the first VDD signal to the gamma voltage generator 170 . The power supply unit 150 is configured to be connected to the data driver 144 through the second VDD line 194 .

The second VDD line 194 is a dedicated signal supply line configured to supply the second VDD signal to the data driver 144 . Accordingly, the power supply unit 150 is configured to supply the first VDD signal and the second VDD signal to the gamma voltage generator 170 and the data driver 144 , respectively. According to the above configuration, since each VDD line is separated, coupling between the data driver 144 and the gamma voltage generator 170 is reduced. Accordingly, interference between the first VDD signal and the second VDD signal is reduced.

The gamma voltage line 196 is a line configured to supply the gamma voltage generated by the gamma voltage generator 170 to the data driver 144 .

The gamma voltage generator 170 generates a gamma voltage and provides it to the data driver 144 . The gamma voltage is a reference voltage used when converting a digital image signal into an analog image signal. Gamma voltages may be defined as gamma reference voltages. The gamma voltage may be configured to generate, for example, 256 grayscale voltages to display a digital image signal having an 8-bit grayscale. Alternatively, the gamma voltage may be a 10-bit gray scale. However, the present invention is not limited thereto, and the gamma voltage may be set to various numbers. In addition, the gamma voltage generator 170 does not generate voltages corresponding to all grayscales, for example, generates only 16 gamma voltages, and the data driver 132 is configured to generate grayscale voltages based on the gamma voltages. can

The horizontal crosstalk compensator 190 is disposed between the first VDD wiring 192 connecting the power supply unit 150 and the gamma voltage generation unit 170 and is input to the gamma voltage generation unit 170 when horizontal crosstalk occurs. A function of alleviating the sudden voltage reduction of the first VDD signal is performed. That is, the horizontal crosstalk compensator 190 is configured to reduce the level of horizontal crosstalk. More specifically, the horizontal crosstalk compensator 190 allows the horizontal crosstalk to be generated gently so that the viewer cannot easily recognize the horizontal crosstalk. That is, the horizontal crosstalk compensator 190 is configured to provide an effect of alleviating the sudden voltage reduction of the first VDD signal supplied from the power supply unit 150 through the first VDD line 192 when the horizontal crosstalk occurs. . In addition, the horizontal crosstalk compensator 190 is preferably disposed at the input of the gamma voltage generator 170 .

Hereinafter, a circuit configuration of the horizontal crosstalk compensator 190 will be described in detail with reference to FIG. 2 .

The horizontal crosstalk compensator 190 includes at least a first resistor R1 , a second resistor R2 , and a first capacitor C1 , and one end of the first resistor R1 is a first VDD wiring 192 . and the other end of the first resistor R1 is connected to one end of the second resistor R2 and one end of the first capacitor C1, the other end of the second resistor R2 and the first capacitor C1 The other end is configured to be grounded. In this case, the resistance value of the first resistor R1 is configured to be less than the resistance value of the second resistor R2 .

According to the above configuration, the horizontal crosstalk compensator 190 has a characteristic of filtering the high frequency component of the first VDD signal. And the output of the horizontal crosstalk compensator 190 is reduced by the above-described configuration.

For example, the resistance value of the first resistor R1 is set to 4.7 KΩ, the resistance value of the second resistor R2 is set to 100 KΩ, and the capacitance value of the first capacitor C1 is set to 0.47 μF In one case, the voltage of the first VDD signal may be reduced by about 4.7% by the horizontal crosstalk compensator 190 . Accordingly, the gamma voltage of the gamma voltage generator 170 may be set by reflecting the voltage reduction of the first VDD signal. Alternatively, the first VDD voltage of the power supply unit 150 is set to increase by the reduced amount by reflecting the voltage reduction amount of the first VDD signal, so that substantially the same first VDD voltage may be output even if the reduction amount is achieved.

Hereinafter, another embodiment of the horizontal crosstalk compensator 190 will be described in detail with reference to FIG. 3 . A buffer unit 194 may be additionally disposed at an output terminal of the horizontal crosstalk compensator 190 . The buffer unit 194 receives the first VDD signal of the input terminal and the first VDD signal of the output terminal of the horizontal crosstalk compensator 190 at the same time to compensate for crosstalk, and configured to provide an effect of compensating for a voltage reduction of the first VDD signal. According to the above-described buffer 194 , there is an effect that the reduction of the first VDD signal can be simply compensated for without special control in the power supply unit 150 .

Hereinafter, a horizontal crosstalk phenomenon of the liquid crystal display 100 according to an exemplary embodiment of the present invention will be described with reference to FIGS. 4A to 4D .

4A is an image signal displayed on the liquid crystal display 100 as a test pattern. The test pattern is a pattern used to determine horizontal crosstalk, and the level of horizontal crosstalk can be determined by displaying the test pattern on the liquid crystal panel 104 . To describe the test pattern in more detail, there is a rectangular area in the center of the test pattern. A gray level value of such a rectangular region may be 255 indicating the highest luminance. However, the present invention is not limited thereto. The grayscale value of the peripheral region of the test pattern may be 64 indicating a luminance darker than that of the central rectangular region. The above-described grayscale values are exemplary values, and are not limited thereto.

For example, the amount of current required to charge the high grayscale region of the test pattern may be 400mA. In addition, the amount of current required to charge the low grayscale region of the test pattern may be 200mA.

4B is a comparative example for explaining the horizontal crosstalk phenomenon. The liquid crystal panel of the comparative example may be an in-plane switching (IPS) type liquid crystal panel. In addition, the liquid crystal panel may be a liquid crystal panel configured to display black when the grayscale value is 0. Such a liquid crystal panel may be defined as a normally black liquid crystal panel. Since such a liquid crystal panel displays a black image when the current is not charged, more current is required to display a high grayscale image than to display a low grayscale image. That is, a relatively large amount of current is required to display a high grayscale image in the central region of the square.

Accordingly, the data driver of the comparative example requires a large amount of current. That is, this phenomenon may occur due to an increase in the load of the liquid crystal panel according to the high grayscale image signal.

In FIGS. 4B to 4C , the number of gate wirings 130 is schematically illustrated as 100 for convenience of description, but these are exemplary numbers and are not limited thereto.

The comparative example shown in FIG. 4B schematically illustrates a case in which the test pattern of FIG. 4A is displayed on the liquid crystal panel of the comparative example. The comparative example does not include the horizontal crosstalk compensator 190 according to the embodiment of the present invention, and the gamma voltage generator and the data driver of the comparative example are configured to receive a VDD signal through one VDD wire. . In the case of the above-described comparative example, when the VDD signal is supplied to the gamma voltage generator and the data driver through one VDD line, the data driver requires a large amount of current, so the voltage of the VDD signal is reduced and the reduced voltage of the VDD signal It is supplied to this gamma voltage generator. Accordingly, the gamma voltage generator generates a gamma voltage using the reduced voltage of the VDD signal, and thus horizontal crosstalk occurs.

The principle that the voltage of the VDD signal is reduced by increasing the panel load can be described as P=VI. That is, the power applied to the liquid crystal panel 104 may be a product of a voltage and a current. And when the current increases according to the increase in the panel load, the voltage is reduced.

Referring to FIG. 4B , horizontal crosstalk occurred in regions corresponding to the left and right sides of the high grayscale rectangular central region. For example, the gradation in the horizontal crosstalk region is reduced from the 64 gradation value to the 30 gradation value. Also, the gradation in the high gradation region is reduced from the 255 gradation value to the 190 gradation value. The reason is that the voltage of the VDD signal input to the gamma voltage generator 170 is reduced, so that even the voltage of the gamma voltage generated based on the VDD signal is affected.

In particular, when the test pattern shown in FIG. 4A is displayed on the liquid crystal panel of the comparative example of FIG. 4B, the gate driver sequentially scans from the first gate line to the nth gate line, and sub-pixels (PXL) connected to each gate line. ) to charge the video signal. In addition, the amount of current required for the sub-pixels PXL connected to the gate wiring increases from the beginning to the end of the central high grayscale region. Accordingly, the amount of current supplied to the power supply unit increases as the amount of current increases from the corresponding gate line, and the voltage of the VDD signal decreases. In addition, the reduction degree of the voltage of the VDD signal has a characteristic proportional to the left and right widths of the high grayscale region of the test pattern. Accordingly, the image quality of the liquid crystal panel is reduced in this test pattern.

In particular, the reason the crosstalk is easily recognized is that the boundary of the crosstalk area is clearly recognized. That is, the change in the gradation due to crosstalk appears in the form of steps.

Referring to FIG. 4C , the liquid crystal display 100 according to the exemplary embodiment of the present invention has a filtered characteristic in that horizontal crosstalk does not abruptly occur but is gradually generated and filtered when compared to the comparative example. For example, when horizontal crosstalk is converted from a 64 gray scale value to a 30 gray scale value, the gray scale value does not change radically but changes gradually. In particular, when the gray level value of the horizontal crosstalk is gradually changed, the degree of recognition by the viewer is lowered, and thus image quality may be improved.

Hereinafter, a function of the horizontal crosstalk compensator 190 will be described with reference to FIG. 4D . FIG. 4D(a) shows, for example, a gamma voltage generator according to time in which the gate wiring 130 sequentially scans from the first gate wiring 130 to the 100th gate wiring 130 from top to bottom in FIG. 4C. It is a waveform diagram schematically illustrating a voltage value of the first VDD signal input to 170 .

The solid line waveform of FIG. 4D(a) represents the voltage value of the VDD signal according to the comparative example. The dotted line waveform of FIG. 4D(a) represents a voltage value of the first VDD signal according to an embodiment of the present invention. The solid line waveform of FIG. 4D(b) represents a gate start pulse (GSP). When the gate start pulse GSP is applied, for example, scanning is sequentially performed from the first gate line 130 to the 100th gate line 130 according to time.

In summary, the current and voltage of the first VDD signal are maintained constant while the gate line 130 scans the low grayscale region. In addition, the horizontal crosstalk compensator 190 has a function of filtering the high frequency component of the first VDD signal. The high-frequency component in the VDD waveform is concentrated in a portion of the step waveform of the solid line waveform in Fig. 4A. The horizontal crosstalk compensator 190 filters these high-frequency components to convert a rectangular waveform into a smooth curved waveform. According to the above-described configuration, there is an effect that horizontal crosstalk can be gently compensated as shown in FIG. 4C . In particular, in this case, there is an effect that the horizontal crosstalk is not easily recognized by the viewer.

In more detail, even if a ripple occurs in the current of the second VDD signal supplied through the second VDD line 194 and is supplied to the data driver 144 , the first VDD signal supplied through the first VDD line 192 is The current is filtered by the horizontal crosstalk compensator 190 .

5A to 5B schematically show a liquid crystal display 200 according to another embodiment of the present invention. Referring to FIG. 5A , the gamma voltage generator 270 is configured to include a bank 271 , a digital to analog converter (DAC) 272 , and a horizontal crosstalk compensator 290 . The bank 271 is configured to receive gamma voltage information to be generated from the controller 146 . The DAC 272 generates a preset gamma voltage. The DAC 272 generates a plurality of gamma voltages Out1 to OutN. In this case, the DAC 272 is configured to receive the VDD signal filtered by the horizontal crosstalk compensator 290 and generate a gamma voltage. According to the above-described configuration, there is an advantage that the horizontal crosstalk compensator 290 can be included in the gamma voltage generator 270 .

The liquid crystal display 200 shown in FIGS. 5A to 5B is a liquid crystal display 200 according to an embodiment of the present invention except that the horizontal crosstalk compensator 290 is built into the gamma voltage generator 270 ( 100), and thus a redundant description thereof will be omitted.

Although embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit of the present invention. . Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100, 200: liquid crystal display device
104: liquid crystal panel
130: gate wiring
132: data wiring
136: flexible circuit board
142: gate driver
144: data driving unit
146: control unit
150: power supply
160: driving circuit board
170, 270: Gamma voltage generator
190, 290: horizontal crosstalk compensation unit
192: first VDD wiring
194: second VDD wiring
196: gamma voltage wiring
AA: pixel area
PA: surrounding area
PXL: sub-pixel

Claims (8)

sub-pixels configured to be driven by a gate signal applied to the gate line from the gate driver and a data signal applied from the data driver to the data line;
a gamma voltage generator configured to supply gamma reference voltages representing grayscale to the data driver;
a power supply configured to supply a first VDD signal to the gamma voltage generator and configured to supply a second VDD signal to the data driver; and
and a crosstalk compensator disposed between the power supply unit and the gamma voltage generator, configured to filter the voltage of the first VDD signal so that a level of crosstalk between the adjacent sub-pixels is reduced;
and the first VDD signal and the second VDD signal are respectively supplied to the gamma voltage generator and the data driver through separate VDD lines. According to claim 1,
the power supply unit, the crosstalk compensator, and the gamma voltage generation unit are disposed, a first VDD line supplying the first VDD signal from the power supply unit to the gamma voltage generation unit and the data driver from the power supply unit The liquid crystal display device of claim 1, further comprising: a circuit board on which a second VDD wiring for supplying a second VDD signal is formed. According to claim 1,
and the crosstalk compensator is configured to filter a high-frequency component of the first VDD signal transmitted from the power supply unit through the first VDD line. 4. The method of claim 3,
The crosstalk compensator includes at least a first resistor, a second resistor, and a first capacitor, one end of the first resistor is connected to the first VDD line, and the other end of the first resistor is one end of the second resistor. and one end of the first capacitor and the other end of the second resistor and the other end of the first capacitor are configured to be grounded. 5. The method of claim 4,
The liquid crystal display device according to claim 1, wherein the crosstalk compensator further includes a buffer configured to compensate the output voltage of the first VDD signal reduced by the crosstalk compensator. 6. The method of claim 5,
A resistance value of the first resistor is configured to be less than a resistance value of the second resistor. a power supply configured to supply a VDD signal;
a first VDD line configured to transmit the VDD signal to a gamma voltage generator;
a second VDD line configured to transmit the VDD signal to a data driver; and a horizontal crosstalk compensator disposed on the first VDD wiring and configured to filter a high frequency component of the VDD signal transmitted to the gamma voltage generator;
and the first VDD wiring and the second VDD wiring are separated from each other. 8. The method of claim 7,
and the driving circuit board is configured to supply a gamma voltage at which horizontal crosstalk is gradually generated to the liquid crystal panel by the horizontal crosstalk compensator.

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