KR102212219B1 - Display device and method for driving thereof - Google Patents

Abstract

In the present invention, a display panel including two or more pixels, a data driver supplying a data voltage to each pixel through a data line, and a timing for controlling the pixels to drive the pixels so that the driving current is not concentrated toward the power line by analyzing the input image data A display device including a controller and a driving method thereof are provided.

Description

DISPLAY DEVICE AND METHOD FOR DRIVING THEREOF}

The present invention relates to a display device that displays an image.

As the information society develops, demands for display devices for displaying images are increasing in various forms, and liquid crystal display devices (LCDs), plasma display devices, and organic light-emitting display devices ( Various types of display devices such as OLED: Organic Light Emitting Display Device) are being used.

On the other hand, in such a display device, while driving the display panel, the driving current is concentrated in a specific area and electromigration occurs, the surface temperature of the display panel rapidly rises due to the concentration of driving current, causing a wiring short, or destroying the current driving element It may be.

Against this background, it is an object of the present invention to provide a display device and a driving method thereof that suppress the occurrence of a burnt defect in a display panel without changing the structure of the display panel.

In addition, an object of the present invention is to provide a display device and a driving method thereof that provide stable driving due to uniform temperature distribution in a display panel.

In order to achieve the above object, in one aspect, the present invention provides a display panel including two or more pixels, a data driver supplying a data voltage to each pixel through a data line, and an input image data to be analyzed to A display device including a timing controller that controls pixels to be driven so that a driving current is not concentrated is provided.

In another aspect, the present invention provides the steps of analyzing a first image pattern of input image data, and a second image pattern having lowered luminance in the power line region when the analyzed first image pattern is a pattern having high luminance in the power line region. It provides a driving method of a display device comprising the step of converting to.

As described above, according to the present invention, the display device has an effect of suppressing the occurrence of burnt defects in the display panel without changing the structure of the display panel.

In addition, according to the present invention, the display device has an effect of providing stable driving because the temperature distribution within the display panel is uniform.

1 is an overall system configuration diagram of a display device to which embodiments are applied.
2 is an external plan view of a display device according to an exemplary embodiment.
3 is a conceptual cross-sectional view of a display device according to an exemplary embodiment.
4 is a configuration diagram of some components of a display device according to another exemplary embodiment.
5A shows a screen state of a general display panel when an ideal pattern is displayed.
5B illustrates setting of a gamma voltage (luminance) of image data according to a position of a general display panel of FIG. 5A.
6 shows the distribution of luminance according to the position of the display panel.
7 shows that the gamma voltage (luminance) of image data is set according to the position of the display panel.
8 illustrates peak luminance in a vertical direction of a display panel at the same gray scale.
9 is a flowchart of a method of driving a display device according to another exemplary embodiment.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to elements of each drawing, it should be noted that the same elements are assigned the same numerals as possible even if they are indicated on different drawings. In addition, in describing embodiments of the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, in describing the constituent elements of the invention, terms such as first, second, A, B, (a), (b) may be used. These terms are only used to distinguish the component from other components, and the nature, order, or order of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected or connected to that other component, but another component between each component It should be understood that elements may be “connected”, “coupled” or “connected”. In the same context, if a component is described as being formed "above" or "below" another component, the component is all formed directly on the other component or indirectly through another component. It should be understood as including.

1 is an overall system configuration diagram of a display device to which embodiments are applied.

Referring to FIG. 1, a display device 100 to which embodiments are applied includes a system board 110, a timing controller 120, a data driver 130, a gate driver 140, a power supply 150, and a display panel. 160).

The system board 110 is connected to a broadcast reception circuit and an external video source interface circuit, and converts digital video data or image data input from the source circuit into an LVDS (Low Voltage Differential Signaling) interface or TMDS (Transition Minimized Differential Signaling). It is transmitted to the timing controller 120 through an interface or the like. In addition, the system board 110 transmits timing signals such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE, and a dot clock DCLK to the timing controller 120.

The timing controller 120 arranges the image data Data input from the system board 110 according to the resolution of the display panel 160 and supplies it to the data driver 130. In addition, the timing controller 120 uses the timing signals Vsync, Hsync, DE, and DCLK input from the system board 110 to control the operation timing of the data driver 130 and the data control signal SDC. , A gate control signal GDC for controlling an operation timing of the gate driver 140 is generated.

The data driver 130 samples and latches the image data input from the timing controller 120 in response to the data control signal SDC from the timing controller 120 and converts it into image data of a parallel data system.

The gate driver 140 drives the gate lines GL1 to GLn in response to the gate control signal GDC from the timing controller 120.

The power supply unit 150 generates driving voltages of the display panel 160 by adjusting the voltage Vin input from the power circuit of the system board 110.

The display panel 160 defines a plurality of pixels at points where the plurality of data lines DL1 to DLm and the plurality of gate lines GL1 to GLn intersect. At least one Organic Light Emitting Diode including a pixel electrode, a common electrode, and an emission layer is connected to each pixel. The emission layer included in each organic light emitting diode may include at least one emission layer or a white emission layer among red, green, blue, and white emission layers. In addition, each pixel includes a driving transistor that supplies a driving current to each pixel electrode.

Meanwhile, when driving a display device using a current driving device such as an organic light emitting display device, in particular, when driving a UHD (2K4K)-class resolution large-area display device, power design of the display panel becomes important.

Typically, power is supplied to the display panel 160 only from a printed circuit board or a multilayer circuit board positioned on one side of the display panel 160.

However, when the high-resolution large-area display device is driven as described above, the effect of voltage drop/rising due to the power line in the display panel 160 increases, and thus the luminance uniformity in the display panel 160 decreases. There is a risk of occurrence.

In addition, in order to prevent the current from being concentrated in a specific area, for example, a resistance is attached to the wiring so that the area where the resistance is located allows less current to flow than other areas.

In addition, in order to solve the above-described problem, in a large-area display device, as described below with reference to FIGS. 2 and 3, an auxiliary electrode structure may be applied to distribute the driving current in the display panel 160.

2 is an external plan view of a display device according to an exemplary embodiment. 3 is a conceptual cross-sectional view of a display device according to an exemplary embodiment.

1 and 2, a display device 400 according to an embodiment is an example of the display device 100 described with reference to FIG. 1.

The display device 200 according to an exemplary embodiment is a printed circuit board (PCB) in which a timing controller 120 for controlling the data driver 130 and the gate driver 140 is implemented as described with reference to FIG. 1. ), 224). In addition, in the multilayer circuit board 224 on which the timing controller 120 is implemented, the power supply unit 150 described in FIG. 1 is implemented, or power lines supplying power to the display panel from the external power supply unit 150 (for example, For example, a base voltage supply line, a high voltage supply line, etc.) may be formed.

Meanwhile, the data driver 130 for driving the data line DL includes a tape carrier package (TCP) type or a circuit film 226 of a flexible printed circuit (FPC) on a data pad connected to the data line. It can be mounted on one side of the display panel. The data driver 130 may be implemented on the circuit film 226 as an integrated circuit.

The substrate 210 is largely composed of an active area or a display area AA for displaying an image and a non-active area or a non-display area NA surrounding the display area AA.

The non-display area NA surrounding the substantially rectangular display area AA is a first non-display area NA1 and a first non-display area on one side of the display area AA (for example, the upper side in FIG. 3 ). The second non-display area NA2 on the opposite side of (NA1) (for example, the lower side in FIG. 3), the third non-display on the left and right of the first non-display area NA1 and the second non-display area NA2 It includes an area NA3 and a fourth non-display area NA4.

In the first non-display area NA1 surrounding one side of the display area AA, a plurality of circuit films 226 on which the data driver 130 is mounted are provided with a data pad 228 and a base voltage pad (VSS pad, 230). Is pad bonded to each other. A base voltage supply line for supplying a base voltage from a power supply unit 150 implemented outside the multilayer circuit board 224 or the multilayer circuit board 224 is formed on the circuit film 226 on which the data driver 130 is mounted. . In the present specification, the base voltage may be a ground voltage, but is not limited thereto and may mean a voltage that is relatively lower than a high potential voltage.

A data line DL is formed extending from the data pad 228. The connection line between the data pad 228 and the data line DL is also referred to as a data link line (DLL). A first base voltage link line 232 is formed extending from the base voltage pad 230.

2 and 3, two or more first base voltage link lines 232 are formed on a substrate 210 in a first non-display area NA1, and in a second non-display area NA2. Two or more second base voltage link lines 240 are formed on the substrate 210.

One end of each first base voltage link line 232 in the first non-display area NA1 is integrally formed with each base voltage pad 230 as described above.

On the substrate 210, a common electrode 222 is formed on the entire surface of the display area AA and a partial area of the non-display areas NA1 and NA2. The common electrode 222 is connected to the first base voltage link line 232 through a first contact hole 244 formed in the insulating layer 224 in the first non-display area. In addition, the common electrode 222 is connected to the second base voltage line 240 through a second contact hole 246 formed in the insulating layer 224 in the second non-display area.

An encapsulation substrate 254 is formed to seal pixels formed on the substrate 210 in a plan view, and is sealed with an adhesive layer 256 between the substrate 210 and the encapsulation substrate 254. In other words, on the substrate 210, between the ground voltage pad 230 and the common electrode 222 in the first non-display area NA1, the connector 224 and the common electrode in the second non-display area NA2. The adhesive layer 256 seals the substrate 210 and the encapsulation substrate 254 in a position spaced apart from the common electrode 222 in the third non-display area and the fourth non-display area between 222.

Meanwhile, a wire-shaped auxiliary electrode line 258 is formed from the multilayer circuit board 224 to the connector 243 of the second non-display area NA2 enclosed on the outside of the encapsulation board 254. . The auxiliary electrode line 258 is a power line for transferring a base voltage from the power supply unit 150 to the second base voltage link line 240 formed in the second non-display area NA2. In the above-described embodiment, the auxiliary electrode line 258 has been described as a power line that transmits a base voltage, but the present invention is not limited thereto, and any power source that transmits power from the power supply unit 150 to the second non-display area NA2 It can be a line.

The auxiliary electrode line 258 can reduce the amount of driving current flowing in a specific area by distributing current in the display panel 160. In the case of using the auxiliary electrode structure, when an ideal pattern, for example, all gray, etc. is displayed on the display panel 160, there is no big problem because current flows to all auxiliary electrode lines.

However, when driving while reproducing an actual image, current may be concentrated toward the auxiliary electrode line 258 in a specific pattern. That is, when the luminance peak pattern is displayed only on the auxiliary electrode line 258 on the display panel 160 according to the image data, the driving current may not flow evenly in all areas of the display panel 160. Therefore, when the above pattern is displayed on the display panel 160, there is a possibility that the driving current is concentrated in a specific area.

When the current is concentrated toward the auxiliary electrode line 258, an overcurrent flows in the corresponding region beyond the limit that can be supplied. As a result, electromigration may occur in the wiring, resulting in a burnt phenomenon such as a wiring loss and a wiring short.

As a result, during driving of the display panel, electromigration occurs at the side of the auxiliary electrode line 258 where the driving current is concentrated, the surface temperature of the display panel rapidly rises due to the concentration of driving current, causing a wiring short, or a current driving element (e.g. For example, driving transistors or organic light emitting diodes) may be destroyed. If such a wiring bunt occurs while a customer is watching a display, it can be a big problem.

4 is a configuration diagram of some components of a display device according to another exemplary embodiment.

Referring to FIG. 4, a display device 400 according to another exemplary embodiment includes a display panel 160 including two or more pixels, a data driver 130 supplying a data voltage to each pixel through a data line, and a data driver. It is the same as the display device 200 according to the exemplary embodiment described with reference to FIG. 2 in that it includes a timing controller 120 that supplies image data. The display device 400 according to another exemplary embodiment may additionally include a memory 170.

In the display device 400 according to another exemplary embodiment, the timing controller 120 may analyze the input image data Data and control the pixels to be driven so that the driving current is not concentrated toward the power line.

In other words, the timing controller 120 interprets the first image pattern of the input image data Data as shown in FIG. 4, and when the analyzed first image pattern is a pattern having high luminance in the power line region, the power supply It can be converted into a second image pattern with lowered luminance in the line area. The timing controller 120 supplies the image data Data' converted into the second image pattern to the data driver 130.

The timing controller 120 may store the input image data Data in the memory 170 before displaying the image on the display panel 160 and then analyze the first image pattern of the stored image data Data. . The memory 170 used for this may be located in the timing controller 120 or may be implemented separately from the timing controller 120. For example, the memory 170 may be a frame buffer located in the timing controller 120, but is not limited thereto.

At this time, the power line is located outside the encapsulation plate 254 that seals the display panel 160 described with reference to FIGS. 2 and 3 and supplies a common voltage of the pixels to the opposite side of the display panel 160. Although it may be 558, the present invention is not limited thereto, and may be any power line that transfers power from the power supply unit 150 to the second non-display area NA2. Hereinafter, the auxiliary electrode line 258 shown in FIGS. 2 and 3 will be exemplarily described as a power line, but the present invention is not limited thereto.

5A shows a screen state of a general display panel when an ideal pattern is displayed. 5B illustrates setting of a gamma voltage (luminance) of image data according to a position of the general display panel shown in FIG. 5A. In FIG. 5B, the long axis of the display panel 160 shown in FIG. 5A is indicated by the x axis, and the short axis of the display panel is indicated by the y axis.

When the auxiliary electrode structure is used as described above, when an ideal pattern, for example, all gray, etc. is displayed on the display panel 160 as shown in FIG. 5A, the entire display panel 160 as shown in FIG. 5B Since it has a uniform luminance, current is not concentrated toward the auxiliary electrode line in a specific area, for example, in the vertical direction of the display panel 160.

6 shows the distribution of luminance according to the position of the display panel. 7 illustrates setting of a gamma voltage (luminance) of image data according to the position of the display panel.

When driving while reproducing an actual image, the driving current can be concentrated toward the auxiliary electrode line 258 because the auxiliary electrode line region has high luminance in a specific pattern as shown in FIG. 6. When the image data Data is input, the timing controller 120 interprets the image data and generates a first image pattern having high luminance in the auxiliary electrode line region as shown in FIG. 6. Determine whether you have it.

When the analyzed first image pattern is a pattern having high luminance in the auxiliary electrode line region as shown in FIG. 6, the timing controller 120 is a second image having lowered luminance in the power line region as shown in FIG. It can be converted into a pattern. In this case, the timing controller 120 may lower the luminance in the power line region of the second image pattern as much as the luminance of the first image pattern is high in the power line region.

When the first image pattern has a high luminance in the power line region, as shown in FIG. 6, the timing controller 120, as shown in FIG. 7, By lowering the luminance in the power line region of the pattern, as a result, as shown in FIG. 5B, the display panel 160 can be driven with uniform luminance over the entire display panel 160.

8 illustrates peak luminance in a vertical direction of a display panel at the same gray scale.

As shown in FIG. 8, the timing controller 120 reduces the maximum luminance or peak luminance toward the power line in the vertical direction of the display panel 160 at the same gray level so that current is not concentrated in the power line region according to high luminance, as shown in FIG. Can be controlled. As shown in FIG. 8, the maximum luminance may decrease exponentially toward the power line in the vertical direction of the display panel 160 at the same gray scale, but the present invention is not limited thereto.

In this case, the timing controller 120 may convert the maximum luminance in the power line region into a second image pattern having a reference luminance uniformity equal to or higher than the reference luminance uniformity. Although it may vary depending on the type of the display panel 160, for example, if the reference luminance uniformity in the display panel is 80%, the timing controller 120 may determine that the maximum luminance in the auxiliary electrode line region is 80%, which is the reference luminance uniformity. The display panel 160 may be driven by algorithmically converting the image data Data' so as not to be lower than or lower than that.

In this way, the maximum luminance is lowered while the display panel 160 is being driven, and the lowering degree may be controlled so as not to fall below the initial luminance uniformity of the display panel 160.

According to the above-described embodiment, when the image data has a pattern in which a driving current can be concentrated in a power line by analyzing the image data, the image data may be processed and converted into a pattern in which a burnt does not occur and then driven.

According to the above-described embodiment, when an image data is analyzed to recognize a pattern in which a current can be concentrated in a power line region, the peak luminance of the corresponding region may be lowered to be driven.

According to the above-described embodiment, the occurrence of a burnt defect in the display panel 160 can be suppressed because current is not concentrated in a specific area without changing the structure of the display panel 160. In this case, since a burnt defect does not occur in the display panel 160, the temperature distribution within the display panel becomes uniform as much, thereby providing stable driving.

9 is a flowchart of a method of driving a display device according to another exemplary embodiment.

Referring to FIG. 9, a method 900 of driving a display device according to another exemplary embodiment includes storing input image data in a memory before displaying an image on a display panel (S910), and a first method of the input image data. Analyzing the image pattern (S920), and when the analyzed first image pattern is a pattern having high luminance in the power line region, converting it into a second image pattern having lowered luminance in the power line region (S930). have.

In the step of analyzing the first image pattern (S920), the first image pattern of the stored image data may be analyzed. At this time, in step S920 of analyzing the first image pattern by omitting the step (S910) of storing the input image data in the memory before displaying the image on the display panel, the first image pattern of the input image data is analyzed. May be.

In the step of converting to the second image pattern (S930), the luminance in the power line region of the second image pattern may be lowered as much as the luminance of the first image pattern is high in the power line region. As described above, when the first image pattern has a high luminance in the power line region as shown in FIG. 6, the first image pattern powers the second image pattern as much as the high luminance in the power line region as shown in FIG. By lowering the luminance in the line region, as a result, as shown in FIG. 5B, the display panel 160 can be driven with uniform luminance over the entire display panel.

As shown in FIG. 8, the maximum luminance or peak luminance may be lowered toward the power line so that current is not concentrated in the power line region according to the high luminance. As shown in FIG. 8, the maximum luminance may be exponentially lowered toward a simple power line, but the present invention is not limited thereto.

In the step of converting to the second image pattern (S930), the maximum luminance in the power line region may be converted to a second image pattern equal to or higher than the reference luminance uniformity. As described above, if, for example, the reference luminance uniformity in the display panel is 80%, the maximum luminance in the auxiliary electrode line region is equal to or higher than 80%, which is the reference luminance uniformity, to drive the display panel.

As described above, according to the exemplary embodiments, the display device can suppress the occurrence of a burnt defect in the display panel without changing the structure of the display panel.

In addition, according to the present exemplary embodiments, the display device may provide stable driving by having a uniform temperature distribution in the display panel.

Terms such as "include", "consist of", or "have" described above, unless otherwise stated, mean that the corresponding component may be included, and thus other components are not excluded. It should be interpreted as being able to further include other components. All terms, including technical or scientific terms, unless otherwise defined, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms generally used, such as terms defined in the dictionary, should be interpreted as being consistent with the meaning in the context of the related technology, and are not interpreted as ideal or excessively formal meanings unless explicitly defined in the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

120: timing controller
130: data driver
140: gate driver
160: display panel

Claims (10)

A display panel including a display area including two or more pixels, and a first non-display area and a second non-display area other than the display area;
A power supply unit supplying power to the display panel;
A data driver supplying a data voltage to each pixel through a data line;
A timing controller that supplies image data to the data driver; And
A power line connected to the second non-display area and the power supply unit, and located outside the sealing plate for sealing the display panel,
The first non-display area is an area located at one side of the display panel adjacent to the power supply unit,
The second non-display area is an area located on the other side of the display panel far from the power supply,
The timing controller interprets the input image data and, when current is concentrated in the power line, supplies image data with lowered luminance of the input image data to the data driver. The method of claim 1,
The timing controller,
When the first image pattern of the input image data is analyzed and the analyzed first image pattern is a pattern having a high luminance in the power line region, it is converted into a second image pattern with lower luminance in the power line region. Display device. The method of claim 1,
The power line is an auxiliary electrode line that supplies a common voltage of pixels to the opposite side of the display panel. The method of claim 1,
Contains additional memory,
The timing controller,
And analyzing the first image pattern of the stored image data after storing the input image data in the memory before displaying the image on the display panel. The method of claim 2,
The timing controller,
And lowering the luminance in the power line region of the second image pattern as much as the luminance higher in the power line region of the first image pattern. The method of claim 5,
The timing controller,
And converting into the second image pattern having a maximum luminance equal to or lower than the reference luminance uniformity in the power line region. In the method of driving a display device,
The display device,
A display panel including a display area including two or more pixels, and a first non-display area and a second non-display area other than the display area;
A power supply unit supplying power to the display panel;
A data driver supplying a data voltage to each pixel through a data line;
A timing controller that supplies image data to the data driver; And
A power line connected to the second non-display area and the power supply unit, and located outside the sealing plate for sealing the display panel,
The first non-display area is an area located at one side of the display panel adjacent to the power supply unit,
The second non-display area is an area located on the other side of the display panel far from the power supply,
The timing controller is a display device that interprets the input image data and supplies image data with lowered luminance of the input image data to the data driver when current is concentrated in the power line,
The driving method of the display device,
Analyzing a first image pattern of the input image data; And
When the analyzed first image pattern is a pattern having high luminance in a power line region, converting the first image pattern into a second image pattern having lower luminance in the power line region. The method of claim 7,
Further comprising storing the input image data in a memory before displaying the image on the display panel,
In the step of analyzing the first image pattern, the first image pattern of the stored image data is analyzed. The method of claim 7,
In the step of converting to the second image pattern,
The driving method of a display device, wherein the luminance of the power line region of the second image pattern is lowered by a higher luminance of the first image pattern in the power line region. The method of claim 7,
In the step of converting to the second image pattern,
And converting into the second image pattern having a maximum luminance equal to or lower than the reference luminance uniformity in the power line region.

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