KR102478672B1 - Multivision System And the Method of Driving Thereof - Google Patents

Abstract

The present invention has been made to solve the above problems, and relates to a multi-vision system and a driving method thereof capable of equally lowering the luminance of a plurality of display modules while improving the contrast ratio of a screen. The system includes a receiver that receives image data, a calculator that calculates the APL of the display module and image data of the maximum grayscale among the input image data, and transmits the APL and grayscale information of the image data of the maximum grayscale to other display modules. An inter-module transmission/reception unit that transmits to or receives information of other display modules, an APL application unit that applies the reference APL, which is the APL of the reference module having the lowest APL, to the display module, and the display module is not a reference module. , and a luminance compensator for increasing luminance by applying a weight to image data having a higher gradation than the gradation of the maximum gradation image data of the reference display module among the image data input to the display module.

Description

Multivision system and its driving method {Multivision System And the Method of Driving Thereof}

The present invention relates to a multi-vision system and a method for driving the same, and more particularly, to a multi-vision system capable of improving the contrast ratio of a screen while eliminating luminance discontinuity between a plurality of display panels that are continuously arranged to display a single screen, and a method for driving the same. it's about

[Background Art] Recently, a display device displaying an image, which is an information device, has been developed in line with the information age. Among them, an organic light emitting display device does not require a separate light source and displays by including self-emitting organic light emitting elements in units of pixels therein. The advantage of omitting the structure is great, and it is being considered as a next-generation display device.

On the other hand, in places where many people gather, such as stadiums, concert halls, and hospitals, a large display of 100 inches or more is required so that many people can see it at the same time.

However, it is difficult to manufacture a large display of 100 inches or more as a single product due to problems in process and manufacturing cost. Therefore, in order to implement a large display as described above, a multi-vision displaying a single screen by combining a plurality of display modules has been developed, and research on the multi-vision has been actively conducted.

On the other hand, in a display device using a self-emitting element, such as an organic light emitting display device, power consumption increases in proportion to the light emitting area and the brightness of the light. Therefore, if the brightness per gradation level of the display device is fixed based on the small area emitting light, power becomes insufficient when the area emitting light is large, and the brightness per gradation level of the display device is If it is fixed based on a large number of times, the screen becomes too dark when the light emitting area is small.

To solve this problem, a display device using a general self-light emitting element introduces the concept of Average Picture Level (hereinafter referred to as 'APL'), and when the average brightness of the screen is large, the brightness per gradation level is reduced, and when the average brightness of the screen is small, the screen is displayed using a method of increasing the brightness per gradation level.

However, when self-emitting organic light emitting display modules are used in a plurality of display modules constituting a multi-vision, since the APL values of each of the plurality of display modules are different, the brightness per gradation level of the image varies for each display module. Accordingly, even though the same grayscale level is input, each module has a different brightness, resulting in a problem in that luminance discontinuity occurs at the boundary of the display module.

In order to solve the above problem, conventionally, the APL values of all display modules are matched to the display module having the highest APL value among the plurality of display modules, thereby solving the luminance discontinuity between the plurality of display modules in multi-vision. did However, when the APL values of all display modules are matched to the display module having the highest APL value, a problem in that the contrast ratio of the screen is greatly reduced.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a multi-vision system and a driving method capable of improving the contrast ratio of a screen while equally lowering the luminance of a plurality of display modules. .

In order to solve the above problem, the multi-vision system according to the present invention compares the APLs of other adjacent display modules, and the reference module having the highest APL matches the APL, and the other display modules image data input to the reference module. It has a feature of applying a weight to the image data input to each display module so as to have a higher gray level than the image data of the highest gray level among them.

To this end, the multi-vision system according to the present invention includes a receiver for receiving image data, a calculator for calculating APL of the display module and image data of the maximum grayscale among input image data, and an image of the APL and maximum grayscale. an inter-module transmission/reception unit that transmits grayscale information of data to other display modules or receives information of other display modules, and an APL application unit that applies a reference APL, which is the APL of a reference module having the lowest APL, to the corresponding display module; When the display module is not the reference module, a luminance corrector is included to increase luminance by applying a weight to image data having a higher grayscale than the maximum grayscale image data of the reference display module among image data input to the display module.

In the multi-vision system according to the present invention, the image data input to the display modules other than the reference module has a higher grayscale than the image data of the maximum grayscale among the image data input to the reference module. By applying a weight to , it has a characteristic of increasing the luminance and outputting it.

Accordingly, the multi-vision system according to the present invention has an effect of realizing image quality with a high contrast ratio.

In addition, the multi-vision system of the present invention applies a higher weight to image data having a gray level higher than the reference value as the gray level is higher than the reference value, so that the effect of securing luminance continuity even when displaying images spanning several display modules is achieved. have

1 is a front view of a multi-vision according to an embodiment of the present invention.
2 is an exemplary diagram for explaining a multi-vision driving circuit according to the present invention.
3 is an exemplary diagram for explaining a structure of a subpixel included in each display panel.
4 is an exemplary diagram for explaining a timing controller in more detail.
FIG. 5 shows a contrast ratio improvement effect when the multi-vision system according to the present invention is applied, and FIG. 6 shows a graph of a difference in weight of image data having a gray level higher than a reference value.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Like reference numbers throughout the specification indicate substantially the same elements. In the following description, if it is determined that a detailed description of a known technology or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, the component names used in the following description are selected in consideration of the ease of writing the specification, and may be different from the part names of the actual product.

1 is a front view of a multi-vision according to an embodiment of the present invention.

As shown in FIG. 1 , in the multi-vision 100 according to the present invention, a plurality of display modules M1 to M9 are continuously arranged to display a single screen.

2 is an exemplary diagram for explaining a driving circuit of the multi-vision 100 according to the present invention.

The multi-vision 100 according to the present invention includes an image input unit 131, an image distribution unit 132, and a plurality of display modules M1 to M6.

The video input unit 131 receives a video signal from the outside and outputs it to the video distribution unit 132 .

The video distribution unit 132 divides the video data output from the video input unit 131, scales the divided video data according to the resolution of each display module M1 to M6, and then processes each display module M1. ~M6) to supply video data.

Each of the display modules M1 to M6 includes a display panel 170, a gate driver 160, a data driver 150, and a timing controller 140. In this case, the gate driver 160 , the data driver 150 , and the timing controller 140 are defined as panel drivers that drive the display panel 170 .

The timing controller 140 uses signals such as a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a clock signal (CLK), and a data enable signal (DE) input from the image distributor 132 to generate a plurality of A data control signal DCS and a gate control signal GCS are generated.

In addition, the timing controller 140 aligns the image data (RGB Data) input from the image distribution unit 132 of the multi-vision 100 according to the configuration of the display modules M1 to M6, and controls the aligned image data as data. The signal DCS is supplied to the data driver 150, and the gate control signal GCS is supplied to the gate driver 160.

In addition, the timing controller 140 compares the APL of other adjacent display modules M1 to M6 and matches the APL value of the corresponding display module with the reference module having the highest APL.

Next, display modules other than the reference module apply a gain value to the image data input to each display module to have a higher grayscale than the image data of the maximum grayscale among the image data input to the reference module. By applying it, it has the feature of increasing the luminance and outputting it. A detailed description of the timing controller 140 will be described later.

The gate driver 160 receives the gate control signal GCS, generates a scan signal every horizontal period, and supplies it to the gate lines GL.

The data driver 150 converts the digital image data into an analog data voltage using the gamma reference voltage of the data control signal DCS input from the timing controller 140 and supplies it to the data lines DL.

3 is an exemplary diagram for explaining the structure of subpixels provided in each display panel 170 .

The display panel includes sub-pixels arranged in a matrix form in an area defined by crossing the data lines DL and the gate lines GL.

Each sub-pixel includes an organic light emitting diode (OLED) composed of an organic light emitting layer between an anode and a cathode, and a pixel circuit independently driving the organic light emitting diode (OLED).

The pixel circuit includes at least one switching transistor TR1 and TR3, at least one capacitor Cst, and a driving transistor TR2. The plurality of switching transistors TR1 and TR3 charge the capacitor Cst with the data voltage from the data driver 150 in response to the scan signal generated by the gate driver 160 every horizontal period. In addition, the driving transistor TR2 supplies current to the organic light emitting diode according to the data voltage charged in the capacitor Cst to drive the organic light emitting diode OLED.

4 is an exemplary diagram for explaining the timing controller 140 in more detail.

The timing controller 140 includes a receiver 141, a calculator 142, an inter-module transceiver 143, an APL application unit 144, a luminance corrector 145, an image corrector 146, and an image output unit ( 147).

The receiving unit 141 receives image data divided into respective display modules from the image distributing unit 132 and outputs them.

The calculation unit 142 receives the image data divided into the respective display modules, calculates the APL of the corresponding module (here, 'corresponding module' means each display module itself), and then calculates the APL of the corresponding module. Among the image data input to the display module, image data of the maximum gray level is detected.

To this end, the calculator 142 includes an APL calculator 1421 and a maximum data detector 1422.

The APL calculation unit 1421 receives input video data divided into respective display modules, calculates the APL of the corresponding display module, and outputs it to the APL application unit 144.

The maximum data detector 1422 receives the image data and the APL of the display module from the APL calculation unit, calculates image data of the maximum grayscale from the image data input to the display module, and then calculates the image data of the maximum grayscale. And the APL of the display module is output to the inter-module transceiver 143, and the image data of the maximum gray level is output to the luminance compensator 145.

The inter-module transmission/reception unit 143 receives the APL and maximum grayscale image data of the display module, transmits the input to other display modules, receives the APL and maximum grayscale image data information of other display modules, and displays other display modules. The APL of the modules is output to the APL application unit 144, and image data information of the maximum gray level of other display modules is output to the luminance compensator 145.

The APL application unit 144 receives the APL of the corresponding display module from the APL calculation unit 1421 and receives the APL of other display modules from the inter-module transceiver 143, and receives the APL of the corresponding display module and other display modules. APLs of the display modules are compared, and a display module having the highest APL among display modules is recognized as a reference module, and the APL of the reference module is applied as a reference APL to the corresponding display module.

If the display module is a reference module, the APL application unit 144 applies the reference APL to image data input to the display module, and then outputs the image data directly to the image correction unit 147 without applying a weight.

When the corresponding display module is not the reference module, the APL application unit 144 applies the reference APL to image data input to the display module and then outputs the image data to the luminance compensating unit 145 .

The luminance correction unit 145 receives image data of the maximum grayscale of other display modules from the inter-module transceiver 143 and sets the grayscale value of the image data having the maximum grayscale among the image data input to the reference module as a reference value. . In addition, the luminance correction unit 145 receives the image data to which the reference APL is applied from the APL application unit 144, and applies a weight to the image data of the corresponding display module having a gray level greater than or equal to the reference value among the image data to which the reference APL is applied. , The luminance of image data having a gradation higher than the reference value is increased and output to the image compensator 147.

In this case, in order to apply the weight, a method of applying a gain value to image data equal to or greater than the reference value may be used.

At this time, the image correction unit 147 compensates for the image data input from the APL application unit 144 or the luminance correction unit 145, such as compensation for deterioration of thin film transistors or organic light emitting elements in the organic light emitting display device. may be performed, and the image data corrected accordingly is output to the image output unit 148 . The image correction unit 147 may be omitted.

The image output unit 148 outputs corrected image data input from the image correction unit 147 to the data driver 150 .

FIG. 5 shows a contrast ratio improvement effect when a multi-vision system according to the present invention is applied, and FIG. 6 shows a graph of a luminance difference of image data having a gray level higher than a reference value.

The display module M3 located at the lower left of FIG. 5 is the reference module with the highest APL. In the case of the reference module, the luminance of input image data does not increase. At this time, the gray level of the image data having the maximum gray level among the image data input to the reference module is set as the reference value. And, among the image data input to the other display modules M1, M2, and M4, a weight is applied to image data having a gray level greater than or equal to the reference value. Accordingly, the luminance of image data having a gray level greater than or equal to the reference value increases.

In particular, in order to maintain luminance continuity when an image is displayed across a plurality of display modules, as shown in FIG. 6 , the image correction unit 147 assigns a higher weight to image data having a gray level higher than the reference value as the gray level difference from the reference value increases. apply

For example, the star-shaped image of the display module M1 located in the upper left of FIG. 5 is darker than the star-shaped image of the display module M2 located in the upper right. This is because the gray level difference between the image data corresponding to the star-shaped image located at the upper left and the reference value is greater than the gray level difference between the image data corresponding to the star-shaped image located at the upper left and the reference value.

In this way, the image compensator 147 varies the weight according to the degree of grayscale difference between the image data and the reference value, so that the multi-vision system according to the present invention can secure luminance continuity between adjacent panels, and the multi-vision system according to the present invention The system has an effect of securing a high contrast ratio.

Hereinafter, a method of driving a multi-vision system according to the present invention will be described with reference to FIG. 4 .

The video input unit 131 receives a video signal from the outside and outputs it to the video distribution unit 132 .

The video distribution unit 132 divides the video data output from the video input unit 131, scales the divided video data according to the resolution of each display module M1 to M6, and then processes each display module M1. ~M6) to supply video data.

The receiving unit 141 receives image data divided into respective display modules from the image distribution unit 132 and is input, and outputs it to the APL calculation unit 1421 .

The APL calculation unit 1421 receives image data that is divided into respective display modules, calculates the APL of the corresponding display module, and outputs the APL application unit 144 and the maximum data detection unit 1422.

The maximum data detector 1422 receives the image data and the APL of the display module from the APL calculation unit, calculates image data of the maximum grayscale from the image data input to the display module, and then calculates the image data of the maximum grayscale. And the APL of the display module is output to the inter-module transceiver 143, and the image data of the maximum gray level is output to the luminance compensator 145.

The inter-module transmission/reception unit 143 receives the APL and maximum grayscale image data of the display module, transmits the input to other display modules, receives the APL and maximum grayscale image data information of other display modules, and displays other display modules. The APL of the modules is output to the APL application unit 144, and image data information of the maximum gray level of other display modules is output to the luminance compensator 145.

The APL application unit 144 receives the APL of the corresponding display module from the APL calculation unit 1421 and receives the APL of other display modules from the inter-module transceiver 143, and receives the APL of the corresponding display module and other display modules. APLs of the display modules are compared, and a display module having the highest APL among display modules is recognized as a reference module, and the APL of the reference module is applied as a reference APL to the corresponding display module.

When the corresponding display module is a standard module, the APL applying unit 144 applies the standard APL to image data input to the corresponding display module and outputs the applied image correction unit 147.

When the corresponding display module is not the reference module, the APL application unit 144 applies the reference APL to image data input to the display module and then outputs the image data to the luminance compensating unit 145 .

The luminance correction unit 145 receives image data of the maximum grayscale of other display modules from the inter-module transceiver 143 and sets the grayscale value of the image data having the maximum grayscale among the image data input to the reference module as a reference value. . In addition, the luminance correction unit 145 receives the image data to which the reference APL is applied from the APL application unit 144, and applies a weight to the image data of the corresponding display module having a gray level greater than or equal to the reference value among the image data to which the reference APL is applied. , The luminance of image data having a gradation higher than the reference value is increased and output to the image compensator 147.

At this time, the image correction unit 147 compensates for the image data input from the APL application unit 144 or the luminance correction unit 145, such as compensation for deterioration of thin film transistors or organic light emitting elements in the organic light emitting display device. may be performed, and the image data corrected accordingly is output to the image output unit 148 .

The image output unit 148 outputs corrected image data input from the image correction unit 147 to the data driver 150 .

The data driver 150 converts the digital image data into an analog data voltage using the gamma reference voltage of the data control signal DCS input from the timing controller 140 and supplies it to the data lines DL.

The above description is merely illustrative of the present invention, and various modifications may be made by those skilled in the art without departing from the technical spirit of the present invention. Therefore, the embodiments disclosed in the specification of the present invention are not intended to limit the present invention. The scope of the present invention should be construed by the claims below, and all techniques within the scope equivalent thereto should be construed as being included in the scope of the present invention.

M1 to M9: display module 100: multi-vision
131: video input unit 132: video distribution unit
140: timing controller 150: data driver
141: receiving unit 142: calculating unit
1421: APL calculation unit 1422: maximum data detection unit
143: transceiver between modules 144: APL application unit
145: luminance correction unit 147: image correction unit
148: video output unit 170: display panel

Claims (8)

It includes a plurality of display modules that are continuously arranged to form a single screen,
Each of the display modules,
A display panel having a plurality of subpixels each including a light emitting element in a matrix form;
APL (average screen brightness) is compared with other adjacent display modules, and the APL value is matched to the reference module having the highest APL. Then, other display modules other than the reference module are among the image data input to the reference module. A panel drive unit configured to increase luminance by applying a weight to image data input to each display module to have a higher grayscale than the maximum grayscale image data,
The panel driving unit
In order to match the APL value to the reference module with the highest APL, the APL of the other display modules is received, the APL of the display module is compared with the APL of other display modules, and the display module with the highest APL is compared. is set as the reference module, and transmits/receives image data information with the other display modules so that the APL of the reference module is applied as the APL of the display module. According to claim 1,
The panel driving unit,
a receiving unit for receiving and outputting image data divided into the respective display modules;
a calculation unit that receives the image data divided into the respective display modules, calculates the APL of the corresponding display module, and then calculates image data of the maximum gray level from the image data;
An inter-module transmission/reception unit for receiving and outputting the APL and maximum grayscale image data of the display module to other display modules, and receiving and outputting the APL and maximum grayscale image data information of other display modules;
APLs of other display modules are received from the inter-module transceiver, and APLs of the corresponding display module are compared with APLs of other display modules, and a display module having the highest APL among the display modules is set as a reference module; An APL application unit that applies the APL of the reference module as the APL of the display module;
When the image data of the maximum gray level of the other display modules is received from the inter-module transceiver and the image data of the maximum gray level of the corresponding display module is input from the calculation unit, and the display module is not the reference module, the A multi-vision system comprising: a luminance corrector configured to increase luminance by applying a weight to image data of a corresponding display module having a gradation equal to or greater than the reference value, using a gradation value of maximum image data of a reference module as a reference value. According to claim 2,
The calculator,
An APL calculation unit that receives the image data divided into the respective display modules and calculates and outputs the APL of the corresponding display module; and
After receiving the image data and APL from the APL calculating unit, calculating image data of the maximum grayscale from the image data input to the display module, the image data of the maximum grayscale and the APL of the corresponding display module are calculated by the module. A multi-vision system including a maximum data calculator for outputting the image data of the maximum grayscale to the luminance compensator, as well as outputting the image data to the inter-transmitting/receiving unit. According to claim 2,
When the corresponding display module is a reference module, the multi-vision system outputs the image data of the corresponding display module without applying a weight. According to claim 2,
Among the image data of the display module having a gray level higher than the reference value, a higher weight is applied to image data having a larger gray level difference from the reference value. Receiving and outputting image data divided into respective display modules and input;
receiving the divided image data input to each of the display modules, calculating the APL of the corresponding display module, and then calculating and outputting image data of the maximum grayscale from the image data;
receiving and transmitting the APL and maximum grayscale image data of the display module to other display modules, and receiving and outputting the APL and maximum grayscale image data information of other display modules;
The APL of the other display modules is received, the APL of the display module is compared with the APL of the other display modules, the display module having the highest APL among the display modules is set as a reference module, and the APL of the reference module is set. Applying as the APL of the display module, and
In addition to receiving the image data of the maximum grayscale of the other display modules, the image data of the maximum grayscale of the corresponding display module is input, and when the corresponding display module is not the reference module, the grayscale value of the maximum image data of the reference module A method of driving a multi-vision system comprising increasing luminance by applying a weight to image data of a corresponding display module having a gradation greater than or equal to the reference value, using as a reference value. According to claim 6,
A method of driving a multi-vision system for outputting image data of the corresponding display module without applying a weight when the corresponding display module is a reference module. According to claim 6,
Among the image data of the display module having a gray level greater than or equal to the reference value, a higher weight is applied to image data having a greater gray level difference from the reference value.

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