KR102185696B1 - Display apparatus and control method thereof - Google Patents

Abstract

A display device is disclosed. The display device includes a display panel composed of a plurality of pixels provided at a point where data lines and gate lines cross, a source driver IC disposed on one side of the display panel to apply a data voltage to the data lines, A gate driver IC that is disposed on only one of two sides adjacent to one side of the display panel to apply a gate driving voltage to the gate lines, and a timing for controlling the timing at which the data voltage and the gate driving voltage are applied A controller (timing controller) and a gate driving voltage applied to at least one of a plurality of pixels are fed back, a distortion of a gate driving voltage applied to at least one pixel is detected based on the feedback voltage, and a distorted gate is driven And a control unit that adjusts the intensity of the gate driving voltage applied to the gate lines to compensate for the voltage and applies it to the gate line.

Description

Display device and its control method {DISPLAY APPARATUS AND CONTROL METHOD THEREOF}

The present invention relates to a display device and a control method thereof, and more particularly, to a display device that compensates for luminance uniformity of a display panel, and a control method thereof.

In general, the liquid crystal display (Liquid Crystal Display; hereinafter referred to as “LCD”) is a trend in which its application range is widely developed due to features such as light weight, thinness, and low power consumption. According to this trend, LCD is applied to office automation equipment, audio/video equipment, and various user terminal equipment. Meanwhile, the LCD displays an image by adjusting the transmittance of the light beam according to an image signal applied to a plurality of control switches arranged in a matrix form.

On the other hand, since the LCD is a light-receiving device that does not emit light by itself, a backlight having a high transmittance is provided on the rear surface of the liquid crystal panel so that the image displayed on the LCD can be clearly viewed with uniform brightness.

However, when the size of the panel increases, such as a large LCD, the RC delay of each gate line also increases, and when the RC delay increases, there is a problem that non-uniformity of luminance on the screen increases. To solve this problem, conventionally, a gate driver IC is connected to one side of the display panel, and a gate driver IC for compensating the RC delay is connected to the other side of the display panel. A method of applying gate power to the line was used.

However, in this method, since the bezels for the gate driver IC must be present on both sides of the display panel, the connection terminal of each display device in a multi-display system that connects and uses a plurality of display devices such as multivision. There was a lot of difficulty in viewing due to the bezel that exists in. In addition, since the number of driver ICs doubled, the competitiveness of the product was inevitably reduced.

Therefore, in order to solve this problem, even if a gate driver IC is provided on only one side of the display device, a solution for compensating for a luminance non-uniformity without RC delay is required.

The present invention has been conceived to solve the above-described problem, and an object of the present invention is to provide a display device capable of compensating for a luminance unevenness phenomenon even when a gate driver IC provided only on one side of the display is used, and a control method thereof. .

A display device according to an embodiment of the present invention includes a display panel including a plurality of pixels provided at a point where data lines and gate lines cross, and is disposed on one side of the display panel to apply a data voltage to the data lines. A source driver IC to be applied, a gate driver IC disposed on only one of two sides adjacent to the one side of the display panel to apply a gate driving voltage to the gate lines, and the plurality of Receive feedback of a gate driving voltage applied to at least one of the pixels of, detect distortion of the gate driving voltage applied to the at least one pixel based on the feedback voltage, and compensate for the distorted gate driving voltage. And a control unit for adjusting the intensity of the gate driving voltage applied to the gate lines and applying it to the gate line.

In addition, a timing controller for controlling a timing at which the data voltage and the gate driving voltage are applied may be further included, wherein the controller is disposed between the timing controller and the gate driver IC to A gate driving voltage whose intensity is adjusted according to a timing signal applied from the controller may be applied.

In addition, the gate driving voltage is applied to the gate lines in the form of a square wave, and the control unit is configured to compensate for a shortage of charging time generated in the at least one pixel due to the distorted gate driving voltage. The strength of the voltage in the section in which the shortage of the charging time occurs may be increased.

In addition, the controller may receive feedback of a gate driving voltage applied to at least one pixel located farthest from the gate driver IC among the plurality of pixels.

In addition, a backlight unit for providing a backlight to the display panel and a backlight driving unit for driving the backlight unit further include, wherein the backlight driving unit includes luminance of the backlight provided to the backlight unit in a direction away from the gate driver IC It is possible to drive the backlight unit so that is increased.

In addition, the control unit generates a synchronization signal at each time point when the gate driving voltage is applied to the gate line and provides it to the backlight driving unit, and the backlight driving unit includes the gate driving voltage based on the received synchronization signal. The backlight unit may be driven to provide the backlight when a driving voltage is applied.

In addition, according to the position of each pixel constituting the display panel, a lookup table in which the luminance value of the light source to be irradiated to each pixel is matched for each pixel in order to keep the brightness of the display panel constant. A storage unit for storing may be further included, and the backlight driver may drive the backlight unit using the previously stored lookup table.

In addition, the backlight driver may linearly increase the luminance of the backlight.

In addition, a backlight unit for providing a backlight to the display panel and a backlight driving unit for driving the backlight unit further include, wherein the backlight unit includes, in the gate line, so that the luminance of the pixels included in the gate line is constant. The position of the light source can be adjusted and designed.

On the other hand, according to an embodiment of the present invention, a method of controlling a display device includes, on a display panel, data lines to which a data voltage is applied from a source driver IC and gate lines to which a gate driving voltage is applied from a gate driver IC. Feedback of a gate driving voltage applied to at least one of a plurality of pixels provided at a point, detecting distortion of a gate driving voltage applied to the at least one pixel based on the feedback voltage, the distorted And adjusting the intensity of the gate driving voltage applied to the gate lines to compensate for the gate driving voltage, and applying the adjusted gate driving voltage to the gate line.

In the applying step, a gate driving voltage whose intensity is adjusted according to a timing signal applied from a timing controller for controlling a timing at which the data voltage and the gate driving voltage are applied may be applied.

In addition, the gate driving voltage is applied to the gate lines in the form of a square wave, and the adjusting may include the square wave in order to compensate for a shortage of charging time generated in the at least one pixel by the distorted gate driving voltage. In may increase the strength of the voltage in the section in which the shortage of the charging time occurs.

In addition, in the receiving of the feedback, a gate driving voltage applied to at least one pixel located farthest from the gate driver IC among the plurality of pixels may be fed back.

Further, the step of increasing the brightness of the backlight provided to the backlight unit in a direction away from the gate driver IC may be further included.

Increasing the luminance of the backlight may include generating a synchronization signal each time the gate driving voltage is applied to the gate line, and when the gate driving voltage is applied based on the synchronization signal. It may include providing the backlight to.

In addition, in the step of increasing the luminance of the backlight, the luminance value of the light source to be irradiated to each pixel in order to keep the luminance of the display panel constant according to the position of each pixel constituting the display panel The luminance of the backlight may be increased by using a lookup table matched for each pixel.

In addition, the increasing step may linearly increase the luminance of the backlight.

According to various embodiments of the present invention described above, even if the gate driver IC is provided only on one side of the display panel, the difference in display quality between the left and right pixels of the display panel due to signal delay can be improved, so that the size of the bezel of the display panel can be reduced. I can.

1 is a block diagram schematically showing a configuration of a display device according to an embodiment of the present invention;
2 is a block diagram showing in detail the configuration of a display device according to an embodiment of the present invention;
3A is a view for explaining a process in which a gate driving voltage is distorted and a shortage of charging time occurs according to an embodiment of the present invention;
3B is a diagram for explaining a waveform of a gate driving voltage capable of compensating for a charging time according to an embodiment of the present invention;
4 is a view for explaining a waveform of a gate driving voltage for compensating for a shortage of charging time in each frame according to a feedback according to an embodiment of the present invention;
5A and 5B are diagrams for explaining a method of adjusting luminance according to a position of a backlight in order to equalize panel luminance according to another embodiment of the present invention;
6 is a view for explaining a look-up table in which backlight luminance adjusted according to an RC delay value is matched according to an embodiment of the present invention;
7 is a flowchart illustrating a method of controlling a display device according to an embodiment of the present invention.

Before describing the present invention in detail, a method of describing the present specification and drawings will be described.

First, general terms used in the specification and claims are selected in consideration of functions in various embodiments of the present invention. However, these terms may vary depending on the intention of a technician in the field, legal or technical interpretation, and the emergence of new technologies. In addition, some terms may be terms arbitrarily selected by the applicant. These terms may be interpreted as the meanings defined in the present specification, and if there is no specific term definition, they may be interpreted based on the general contents of the present specification and common technical knowledge in the art.

In addition, the same reference numbers or numerals in each drawing attached to the present specification indicate parts or components that perform substantially the same function. For convenience of description and understanding, different embodiments will be described using the same reference numbers or symbols. That is, even if all the components having the same reference numerals are shown in a plurality of drawings, the plurality of drawings do not mean one embodiment.

In addition, terms including ordinal numbers such as “first” and “second” may be used in the specification and claims to distinguish between components. These ordinal numbers are used to distinguish the same or similar constituent elements from each other, and the meaning of the term should not be limitedly interpreted due to the use of such ordinal numbers. For example, components combined with these ordinal numbers should not be interpreted as limiting the order of use or arrangement by the number. If necessary, each of the ordinal numbers may be used interchangeably.

In the present specification, expressions in the singular include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "comprise" are intended to designate the existence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other It is to be understood that it does not preclude the presence or addition of features, numbers, steps, actions, components, parts, or combinations thereof.

In an embodiment of the present invention, terms such as “module”, “unit”, “part” are terms used to refer to components that perform at least one function or operation, and these components are hardware or software. It may be implemented or may be implemented as a combination of hardware and software. In addition, a plurality of “modules”, “units”, and “parts” are integrated into at least one module or chip, and at least one processor, except when each needs to be implemented as individual specific hardware. It can be implemented as (not shown).

In addition, in an embodiment of the present invention, when a part is connected to another part, this includes not only a direct connection but also an indirect connection through another medium. In addition, the meaning that a certain part includes a certain component means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

Hereinafter, the present invention will be described in detail with reference to the drawings.

1 is a block diagram schematically illustrating a configuration of a display device according to an embodiment of the present invention.

The display device 100 of the present invention includes various types of monitors capable of image processing including a TV, a smart phone, a portable terminal, a mobile terminal, and a personal digital assistant. : PDA), PMP (Portable Multimedia Player) terminal, computer, notebook computer, note pad (Note Pad), Wibro (Wibro) terminal, tablet PC (Tablet PC), can be implemented as a smart TV.

Referring to FIG. 1, a display device 100 according to an embodiment of the present invention includes a display panel 110, a source driver integrated circuit (IC) 120, a gate driver IC 130, and a control unit 140.

The display panel 110 is a component that displays image data. Here, the display panel 110 is implemented in a GIP (Gate In Panel) structure in which a gate line is mounted on the panel. As a representative example, the display panel 110 is preferably implemented as a thin film transistor liquid crystal display (TFT LCD) panel. However, any display panel to which the technical features of the present invention can be applied is not limited thereto, and the scope of the present invention may be extended to various display panels.

In general, a thin film transistor type liquid crystal display panel has a matrix type pixel structure. For example, a plurality of gate lines and data lines perpendicularly cross each other, and a pixel region is formed between each gate line and the data line. In addition, a thin film transistor and a liquid crystal are formed in this pixel region to display a screen. Among the electrode layers constituting such a pixel, the upper electrode is referred to as a pixel electrode, and the lower electrode is referred to as a counter electrode. The on/off of the thin film transistor is controlled according to the level of the gate voltage applied to the gate line, and when the thin film transistor is turned on, the data voltage applied through the data line is transferred to the pixel electrode of the pixel and is opposite to the data voltage. A gray display of the pixel is performed according to a difference from the voltage applied to the electrode.

Meanwhile, the source driver IC 120 and the gate driver IC 130 are connected to the display panel 110. A gate driving voltage and a data voltage are respectively supplied to the display panel 110 through the source driver IC 120 and the gate driver IC 130. In the display panel, the source driver IC and the gate driver IC are arranged in a single bank structure in which one source driver IC and one gate driver IC are arranged on only one side of the display panel, and two sources. The driver IC and the two gate driver ICs are divided into a dual bank structure that is disposed on both sides of the display panel.

As the display panel becomes larger and the multi-vision technology develops, it is necessary to reduce the area occupied by the source driver IC and the gate driver IC. Therefore, a single bank structure is more preferable. However, in a single bank display panel, the gate The signal delay in the line is a problem, so the single bank structure is not widely used.

Specifically, when the gate driver IC is disposed on the left side of the display panel, when a gate driving voltage is applied to any gate line, the gate driving voltage actually measured at the rightmost point of the gate line is at the leftmost point of the gate line. It has a much more delayed waveform than the actually measured gate voltage. Due to the delay in the gate driving voltage, the kickback voltage varies in the pixel region at each point. This is because charge is supplied through the thin film transistor of the pixel at the corresponding position for a predetermined time when the delayed waveform of the gate driving voltage is applied. Even if the data voltage of the same gray scale is applied to the pixel of one line, the gate driver IC and the The voltage charged to the nearest left pixel, the gate driver IC, and the far right pixel differs. The difference in voltage to be charged caused not only the display quality deterioration due to the difference in luminance between the left and right of the display panel, but also DC stress and afterimage problems on the liquid crystal material, which caused the image quality to deteriorate.

The controller 140 is a component for solving this problem, and performs a function of controlling the overall operation of the display device 100.

Specifically, the controller 140 may receive feedback of a gate driving voltage applied to at least one of the plurality of pixels, and detect distortion of the gate driving voltage applied to at least one pixel based on the feedback voltage. In order to compensate for the distorted gate driving voltage, the controller 140 may adjust the intensity of the gate driving voltage applied to the gate lines and apply it to the gate line.

That is, at least one of the pixels included in the gate line is connected to the controller 140, and may transmit the actually applied gate driving voltage to the controller 140 as a feedback voltage. Here, the pixel that feeds back the feedback voltage to the control unit 140 is a pixel in which the distortion of the gate driving voltage occurs most among pixels included in the gate line, that is, a pixel located at a position farthest from the gate driver IC 130. desirable.

2 is a block diagram illustrating in detail a configuration of a display device according to an embodiment of the present invention.

Referring to FIG. 2, a timing controller 150 is a component for controlling timing when a data voltage and a gate driving voltage are applied. Specifically, the timing controller 150 receives RGB data, which is a color signal, a horizontal synchronization signal (H-SYNC), a vertical synchronization signal (V-SYNC), a clock signal MCLK, a data enable signal DE, and the like. In addition, while receiving voltages supplied from a voltage generator (not shown), timing of these signals may be adjusted, signals required for driving the display panel 110 may be generated.

In addition, the timing controller 150 converts the format of RGB data to meet the interface specification of the source driver IC 120 and outputs the converted RGB' data to the source driver IC 120. In addition, the timing controller 150 outputs a data control signal (for example, an output start signal TP, a horizontal start signal STH), and a clock signal HCLK to the source driver IC 120, and the gate control signal ( For example, a vertical start signal (STV), a gate clock signal (CPV), and an output enable signal (OE) are output to the gate driver IC 130.

The source driver IC 120 receives the gradation voltage generated by the voltage generator through the timing controller 150, selects an appropriate gradation voltage according to RGB data, and converts it so that it can be applied to the display panel 110. It can be applied to each of the 110 data lines.

Specifically, the source driver IC 120 selects gray voltages corresponding to RGB' data among gray voltages generated in response to data control signals TP, STH, and HCLK provided from the timing controller 150, and Gray voltages are applied as data signals to respective data lines of the display panel 110.

The gate driver IC 130 receives the gate voltage generated by the voltage generator through the timing controller 150 and converts it appropriately so that it can be applied to the display panel 110, and then to each gate line of the display panel 110. Can be approved.

Specifically, the gate driver IC 130 receives the gate-on voltage Von and the gate-off voltage Voff, and sequentially in response to the gate control signals STV, CPV, OE provided from the timing controller 150. A gate driving voltage having a gate-on voltage Von is output. The gate driving voltage is sequentially applied to the gate lines of the display panel 110 to sequentially scan the gate lines. In this case, the display apparatus 100 may further include a regulator that converts the input voltage into a gate-on voltage Von and a gate-off voltage Voff and outputs the converted voltage.

When gate signals are sequentially applied to each of the gate lines, data signals are applied to each data line in synchronization therewith. When a gate signal is applied to the selected gate line, the thin film transistor Tr connected to the selected gate line is turned on in response to the gate signal. When a data signal is applied to the data line to which the turned-on thin film transistor Tr is connected, the applied data signal is charged in the liquid crystal capacitor and the storage capacitor through the turned-on thin film transistor Tr.

The liquid crystal capacitor adjusts the light transmittance of the liquid crystal according to the charged voltage. The storage capacitor may accumulate a data signal when the thin film transistor Tr is turned on, and apply the data signal accumulated when the thin film transistor Tr is turned off to the liquid crystal capacitor to maintain charging of the liquid crystal capacitor. Through this method, the display panel 110 may display an image.

Meanwhile, as shown in FIG. 2, the control unit 140 may be disposed between the timing controller 150 and the gate driver IC 130. The controller 140 may receive a timing signal for controlling timing when the data voltage and the gate driving voltage are applied from the timing controller 150.

The controller 140 may apply a gate driving voltage whose intensity is adjusted according to a timing signal applied from the timing controller 150 to the gate line. The control unit 140 is also referred to as a compensation circuit in that it can compensate the charging time of each pixel according to the original gate driving voltage even if the applied gate driving voltage is distorted by applying the gate driving voltage whose intensity is adjusted to the gate line. can do.

Here, the gate driving voltage is applied to the gate lines in the form of a square wave, and the control unit 140 compensates for the shortage of charging time generated in at least one pixel by the distorted gate driving voltage. The intensity of the voltage in the generated section can be increased. At this time, the square wave has the original voltage intensity of the corresponding section (ON-OFF section) after a certain period of time from the point when the gate is changed from OFF to ON (OFF-ON section), and a certain time before the point when the gate is changed from ON to OFF. It may be of a form higher than the intensity of the square wave. Detailed information about this will be described later with reference to FIG. 3.

The voltage generator (not shown) may generate a voltage required for driving the display panel 110, that is, a gate on/off voltage, a grayscale voltage, and a counter electrode voltage, and supply the voltage to the timing controller 150.

Meanwhile, the display panel (TFT-LCD panel) 110 may receive a backlight from the backlight unit 160 and the backlight driver 170.

The backlight unit 160 is disposed on the rear surface of the display panel 110 and may supply light of a desired luminance to the display panel 110 in response to a driving signal supplied from the backlight driver 170. The backlight unit 160 may include a plurality of light sources, and the plurality of light sources may be formed of a light emitting diode (LED). In addition, a plurality of light emitting diodes may be connected in series to each other on a printed circuit board forming a plurality of blocks.

The backlight driver 170 may generate a clock signal and a luminance data signal synchronous to the clock signal in response to the enable signal. The luminance data signal includes luminance information for controlling the luminance of the backlight unit 160.

3A is a view for explaining a process in which a gate driving voltage is distorted and a shortage of charging time occurs according to an embodiment of the present invention.

As shown in FIG. 3A, the gate driving voltage applied through the gate driver IC 130 during one horizontal scanning period (one frame) has a waveform 31 in the form of a square wave, and the pulse is used to charge each pixel. It is formed in a width that can have sufficient charging time. The amplitude of the gate driving voltage is formed to be higher than the gate-on level of the FET device. When the gate driving voltage is applied to each gate line of the display panel 110, a distortion phenomenon occurs due to an RC delay, and such distortion may weaken charging characteristics in each pixel.

In more detail, as the waveform of the gate driving voltage is distorted, the high-level period is changed to a waveform 32 that is shortened, thereby reducing the charging time of the pixel. This phenomenon becomes more pronounced as the signal delay increases. Particularly, among the plurality of pixels constituting the gate line, such distortion becomes severe in a pixel located farthest from the gate driver IC 130. Therefore, it is not possible to secure a sufficient charging time for the pixels, so problems such as a decrease in contrast ratio and poor luminance uniformity occur. In particular, the amplitude of the data voltage is large, such as high voltage driving. In some cases, this phenomenon becomes more serious.

3B is a diagram illustrating a waveform of a gate driving voltage capable of compensating for a charging time according to an embodiment of the present invention.

According to FIG. 3B, the controller 140 increases and applies the voltage in the section in which the shortage of the charge time occurs in the square wave in order to compensate for the shortage of charging time generated in at least one pixel by the distorted gate driving voltage. Can be controlled. Specifically, in the waveform of the gate driving voltage, an amplitude of a section in which a shortage of charge time occurs, that is, a section in which a loss of charge time occurs due to distortion, may be formed higher than the gate-on level voltage. In this case, the amplitude of the section in which the loss of the charging time occurs may be formed to be high so that a high-level section capable of having a sufficient charging time is ensured even when distortion occurs.

3B, the controller 140 may apply a gate driving voltage having a waveform 33 capable of compensating for a loss due to distortion to each gate line of the display panel 110. In this case, the gate driving voltage may change to a gate driving voltage having a distorted waveform 34 passing through each pixel of the gate line.

Even if the gate driving voltage having the distorted waveform 34 is distorted, since the charging time of the gate driving voltage before distortion is secured, a difference in charging voltage due to the RC delay may hardly occur. In addition, by not simply increasing the amplitude of the square wave, but only increasing the amplitude of the distorted section, excessive voltage can be prevented from being applied to each pixel. Accordingly, even if distortion occurs according to the RC delay, the charging time of each pixel can be secured.

Hereinafter, as described above, a compensated gate driving voltage capable of compensating for distortion will be referred to as a compensation gate driving voltage for convenience.

4 is a diagram illustrating a waveform of a gate driving voltage for compensating for a shortage of charging time in each frame according to a feedback according to an exemplary embodiment of the present invention.

As shown in FIG. 4, the controller 140 may apply a compensation gate driving voltage to each gate line for each frame. In this case, the compensation gate driving voltage applied to each gate line may have a different shape depending on the degree to which the gate driving voltage is distorted for each frame.

Specifically, when the first gate driving voltage is applied to the gate line in one frame, the OFF-ON period and the ON-OFF period of the waveform 41 of the gate driving voltage are higher than the gate-on level (dotted line) by the first height. It can have a shape. In addition, when the second gate driving voltage is applied to the gate line in the next frame, the OFF-ON period and the ON-OFF period of the waveform 42 of the gate driving voltage have a shape higher than the gate-on level by a second height. I can. That is, the compensation gate driving voltage applied to each frame may have a different shape, and the shape of the compensation gate driving voltage may be determined by the gate driving voltage fed back from the previous frame.

Specifically, the controller 140 may receive feedback of a gate driving voltage applied to at least one of a plurality of pixels of a gate line. Preferably, the controller 140 may receive feedback of a gate driving voltage applied to at least one pixel located at a position furthest from the gate driver IC 130 among a plurality of pixels of each gate line. The controller 140 may receive the actually applied gate driving voltage from the pixel to which the gate driving voltage is applied last in the gate line, and detect the degree of distortion based on the received gate driving voltage. The controller 140 may quantify the distortion of the gate driving voltage applied to the corresponding pixel by referring to the normal gate driving voltage without distortion, and generate a compensation gate driving voltage compensated by the distortion of the corresponding voltage. The generated compensation gate driving voltage is applied to the gate line in a next frame to reduce a charge voltage difference in a corresponding frame.

Since the waveform of the compensation gate driving voltage is determined according to the detected distortion based on the feedback gate driving voltage, the compensation gate driving voltage in each frame may have a different shape.

5A and 5B are diagrams for explaining a method of adjusting luminance according to a position of a backlight in order to equalize panel luminance according to another exemplary embodiment of the present invention.

5A illustrates backlight luminance when a backlight unit providing a backlight to a display panel provides a constant luminance regardless of a position of a pixel.

According to (a) of FIG. 5A, the intensity of the driving voltage according to the position of the backlight may be represented as a graph. In the graph, the horizontal axis represents the position of the backlight unit 160 corresponding to each pixel in one gate line, and the vertical axis represents the intensity of the driving voltage of the backlight driver 170 at each position. As described above, it is common for the backlight driver 170 to apply a constant driving voltage regardless of the position of the backlight unit 160.

According to another embodiment of the present invention, driving voltages having different strengths are applied according to the position of the backlight unit 160 to minimize a difference in luminance due to a difference in charging time. Specifically, as shown in (b) of FIG. 5A, when a constant driving voltage is applied to the backlight unit 160 regardless of the position of the backlight unit 160, there is a difference between the brightness of the backlight unit and the brightness of the display panel. Can occur. Specifically, the luminance of a pixel far from the gate driver IC 130 in one gate line may have a relatively lower luminance than a nearby pixel due to a charging time difference due to an RC delay.

Accordingly, as shown in (a) of FIG. 5B, the backlight driver 170 controls the backlight unit 160 to increase the brightness of the backlight provided to the backlight unit 160 in a direction away from the gate driver IC 130. Can be driven. In this case, the backlight driver 170 may increase the brightness of the backlight linearly or non-linearly.

In this case, due to the backlight unit 160 whose luminance increases in a direction away from the gate driver IC 130, luminance imbalance due to insufficient charging time may be compensated. Therefore, as shown in (b) of FIG. 5B, the brightness provided by the backlight unit 160 is uniform so that the brightness of the display panel 110 is uniformly maintained regardless of the distance from the gate driver IC 130. It may increase in a direction away from the gate driver IC 130. That is, the backlight driver 170 may be driven so that the backlight driving voltage is applied differently for each position of the backlight unit 160, thereby compensating for the left-right luminance imbalance of the display panel 110.

A luminance value provided from each light source included in the backlight unit 16 may be preset and stored in a manufacturing process to compensate for the left-right luminance imbalance of the display panel 110.

In this case, the display device 100 further includes a storage unit (not shown), and the storage unit is configured to maintain a constant luminance of the display panel 110 according to a position of each pixel constituting the display panel 110. A lookup table in which a luminance value of a light source to be irradiated to a pixel is matched for each pixel may be stored.

6 is a diagram for describing a lookup table in which backlight luminance adjusted according to an RC delay value is matched according to an embodiment of the present invention. As shown in FIG. 6, the backlight driving unit 170 may drive the backlight unit 160 using a lookup table stored in the storage unit.

As shown in FIG. 6, the lookup table is matched and stored so that the luminance of the adjusted backlight increases as the RC delay value increases. The luminance of the backlight unit 160 according to the RC delay may be measured during the design and manufacturing process of the display device 100 and stored as a preset value.

Meanwhile, in FIG. 6, only four RC delay values stored by matching corresponding luminances are illustrated, but it will be apparent that the luminance values of each backlight corresponding to a more subdivided RC delay value may be stored.

In addition, as another embodiment of the present invention, the backlight unit 160 may be designed by adjusting the position of the light source in the gate line so that the luminance of the pixels included in each gate line is constant.

That is, the display device 100 adjusts the spacing of light sources that provide backlights to each pixel included in the gate line, so that the light sources at a close distance from the gate driver IC 130 increase the spacing, and the gate driver IC 130 A light source at a distance from) can be arranged with a narrow gap.

Accordingly, the brightness of the backlight by the light source at a distance from the gate driver IC 130 is inevitably higher than the brightness of the backlight by the light source at a distance from the gate driver IC 130. Accordingly, the difference in luminance can compensate for the luminance imbalance of the display panel 110 by canceling the difference in luminance caused by the difference in charging time. At this time, the luminance of the backlight unit 160 according to the RC delay is measured during the design and manufacturing process of the display device 100, and each light source of the backlight unit 160 is based on the measured luminance value. It may be arranged with an interval adjusted so that the luminance is uniform.

7 is a flowchart illustrating a method of controlling a display device according to an embodiment of the present invention.

First, on a display panel, a gate driving voltage applied to at least one of a plurality of pixels provided at a point where the data lines to which the data voltage is applied from the source driver IC and the gate lines to which the gate driving voltage is applied from the gate driver IC cross each other. The feedback is received (S710). Here, the gate driving voltage may be applied in the form of a square wave.

In this case, the gate driving voltage applied to at least one pixel located farthest from the gate driver IC among the plurality of pixels may be fed back.

Thereafter, distortion of the gate driving voltage applied to at least one pixel is detected based on the feedback voltage (S720).

After that, the intensity of the gate driving voltage applied to the gate lines is adjusted to compensate for the distorted gate driving voltage (S730). In this case, in order to compensate for the shortage of charging time generated in at least one pixel due to the distorted gate driving voltage, the intensity of the voltage in the section in which the shortage of charging time occurs in the square wave may be increased.

After that, the adjusted gate driving voltage is applied to the gate line (S740). In this case, a gate driving voltage whose intensity is adjusted according to a timing signal applied from a timing controller for controlling timing at which the data voltage and the gate driving voltage are applied may be applied.

Also, the brightness of the backlight provided to the backlight unit may be increased in a direction away from the gate driver IC. In addition, at this time, a synchronization signal may be generated each time the gate driving voltage is applied to the gate line, and a backlight may be provided at a time when the gate driving voltage is applied based on the generated synchronization signal. In addition, in this case, according to the position of each pixel constituting the display panel, a lookup table in which the luminance value of the light source to be irradiated to each pixel is matched for each pixel is used to keep the brightness of the display panel constant. Thus, the brightness of the backlight can be increased. Here, the luminance of the backlight may be linearly increased.

As described above, according to various embodiments of the present disclosure, by reducing a difference in the amount of charging voltage between left and right pixels of the display panel, a problem of lowering the uniformity of luminance due to signal delay in the gate line may be improved.

The control method according to the various embodiments described above may be implemented as a program and stored in various recording media. That is, a computer program that is processed by various processors and capable of executing the various control methods described above may be used in a state stored in a recording medium.

For example, on the display panel, a gate driving voltage applied to at least one of a plurality of pixels provided at a point where data lines to which a data voltage is applied from a source driver IC and gate lines to which a gate driving voltage is applied from a gate driver IC intersect Receiving a feedback, detecting distortion of the gate driving voltage applied to at least one pixel based on the feedback voltage, the intensity of the gate driving voltage applied to the gate lines to compensate for the distorted gate driving voltage A non-transitory computer readable medium may be provided in which a program for performing the step of adjusting and applying the gate driving voltage whose intensity is adjusted to the gate line is stored.

The non-transitory readable medium refers to a medium that stores data semi-permanently and can be read by a device, not a medium that stores data for a short moment, such as a register, cache, or memory. Specifically, the above-described various applications or programs may be provided by being stored in a non-transitory readable medium such as a CD, DVD, hard disk, Blu-ray disk, USB, memory card, and ROM.

In addition, although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. In addition, various modifications are possible by those of ordinary skill in the art, and these modifications should not be individually understood from the technical spirit or prospect of the present invention.

110: display panel 120: source driver IC
130: gate driver IC 140: timing controller
150: control unit 160: backlight unit
170: backlight driver

Claims (18)

In the display device,
A display panel including a plurality of pixels provided at a point where data lines and gate lines intersect;
A source driver IC disposed on one side of the display panel to apply a data voltage to the data lines;
A gate driver IC disposed on only one of two adjacent side surfaces of the display panel to apply a gate driving voltage to the gate lines; And
A gate driving voltage applied to at least one of the plurality of pixels is fed back, a distortion of a gate driving voltage applied to the at least one pixel is detected based on the feedback voltage, and the distorted gate driving voltage is Including; a control unit for adjusting the intensity of the gate driving voltage applied to the gate lines to compensate for applying to the gate line; and
The gate driver IC,
The display device, wherein the off-on period and the on-off period generate a gate driving voltage having a level higher than that of the gate-on period. The method of claim 1,
A timing controller for controlling a timing at which the data voltage and the gate driving voltage are applied; further comprising,
The control unit,
The display device, which is disposed between the timing controller and the gate driver IC to apply a gate driving voltage whose intensity is adjusted according to a timing signal applied from the timing controller. The method of claim 1,
The gate driving voltage is applied to the gate lines in the form of a square wave,
The control unit,
In order to compensate for a shortage of charging time generated in the at least one pixel due to the distorted gate driving voltage, the intensity of a voltage in a section in which the shortage of the charging time occurs in the square wave is increased. The method of claim 1,
The control unit,
A display device, wherein a gate driving voltage applied to at least one pixel located farthest from the gate driver IC among the plurality of pixels is fed back. The method of claim 1,
A backlight unit for providing a backlight to the display panel; And
Further comprising; a backlight driving unit for driving the backlight unit,
The backlight driver,
The display device, wherein the backlight unit is driven to increase the brightness of a backlight provided to the backlight unit in a direction away from the gate driver IC. The method of claim 5,
The control unit,
Whenever the gate driving voltage is applied to the gate line, a synchronization signal is generated and provided to the backlight driver,
The backlight driver,
Driving the backlight unit to provide the backlight when the gate driving voltage is applied based on the received synchronization signal. The method of claim 6,
According to the position of each pixel constituting the display panel, to keep the luminance of the display panel constant, a lookup table in which the luminance value of the light source to be irradiated to each pixel is matched for each pixel is stored. It further includes a storage unit,
The backlight driver,
A display device for driving the backlight unit using the pre-stored lookup table. The method of claim 5,
The backlight driver,
A display device for linearly increasing the luminance of the backlight. The method of claim 1,
A backlight unit for providing a backlight to the display panel; And
Further comprising; a backlight driving unit for driving the backlight unit,
The backlight unit,
The display device, wherein the position of the light source in the gate line is adjusted so that the luminance of the pixel included in the gate line is constant. In the control method of the display device,
On the display panel, a gate driving voltage applied to at least one of a plurality of pixels provided at a point where the data lines to which the data voltage is applied from the source driver IC and the gate lines to which the gate driving voltage is applied from the gate driver IC intersect is fed back ( feedback) receiving step;
Detecting distortion of a gate driving voltage applied to the at least one pixel based on the feedback voltage;
Adjusting an intensity of the gate driving voltage applied to the gate lines to compensate for the distorted gate driving voltage; And
And applying a gate driving voltage whose intensity is adjusted to the gate line; and
The gate driving voltage whose intensity is adjusted is
The control method, wherein the off-on period and the on-off period are gate driving voltages having a higher level than the gate-on period. The method of claim 10,
The applying step,
And applying a gate driving voltage whose intensity is adjusted according to a timing signal applied from a timing controller for controlling a timing at which the data voltage and the gate driving voltage are applied. The method of claim 11,
The gate driving voltage is applied to the gate lines in the form of a square wave,
The adjusting step,
And increasing the intensity of a voltage in a section in which the shortage of the charging time occurs in the square wave in order to compensate for a shortage of charging time generated in the at least one pixel by the distorted gate driving voltage. The method of claim 11,
The step of receiving the feedback,
A control method for receiving feedback of a gate driving voltage applied to at least one pixel located farthest from the gate driver IC among the plurality of pixels. The method of claim 11,
Increasing the brightness of the backlight provided to the backlight unit in a direction away from the gate driver IC; and further comprising. The method of claim 14,
Increasing the brightness of the backlight,
Generating a synchronization signal each time the gate driving voltage is applied to the gate line; And
And providing the backlight at a time when the gate driving voltage is applied based on the synchronization signal. The method of claim 15,
Increasing the brightness of the backlight,
According to the position of each pixel constituting the display panel, a lookup table in which the luminance value of the light source to be irradiated to each pixel is matched for each pixel is used to maintain the brightness of the display panel constant. Thereby increasing the brightness of the backlight. The method of claim 14,
The increasing step,
The control method of increasing the brightness of the backlight linearly. A computer program stored in a recording medium for processing by a processor to execute the control method according to any one of claims 10 to 17.

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