KR102517246B1 - Curved display device - Google Patents

Abstract

The present invention relates to a curved display device, and a display panel of a curved display device according to the present invention includes at least one border black matrix positioned at a boundary between at least two active areas, and a black matrix positioned within the active areas. The line widths of the internal black matrices are different, and the luminance deviation between the adjacent internal sub-pixels and the boundary sub-pixels with the internal black matrix interposed therebetween can be reduced by adjusting the luminance of the adjacent boundary sub-pixels with the boundary black matrix interposed therebetween.

Description

Curved display device {CURVED DISPLAY DEVICE}

The present invention relates to a curved display device, and more particularly, to a curved display device capable of preventing deterioration in image quality.

BACKGROUND OF THE INVENTION [0002] Video display devices, which implement various information on a screen, are a core technology in the information and communication era, and are developing toward a thinner, lighter, portable and high-performance direction. Accordingly, a flat panel display device capable of reducing the weight and volume, which are disadvantages of a cathode ray tube (CRT), is in the spotlight.

Flat panel display devices generally display images on a flat screen, but recently, a curved display device having a constant curvature radius has been proposed to further satisfy various functions.

However, the curved display device has a problem in that image quality characteristics are deteriorated as the flexible display panel is bent.

The present invention is to solve the above problems, and the present invention provides a curved display device capable of preventing deterioration of image quality.

In order to achieve the above object, a curved display panel of a curved display device according to the present invention includes at least one border black matrix positioned at a boundary between at least two active areas, and an internal black matrix positioned within the active areas. The line widths of the matrices are different, and the luminance deviation between the adjacent inner sub-pixels and the border sub-pixels can be reduced with the inner black matrix interposed therebetween by adjusting the luminance of the adjacent border sub-pixels with the border black matrix interposed therebetween.

In the present invention, the luminance of the boundary sub-pixels located on both sides of the boundary black matrix having a relatively small width is lowered than the luminance of the internal sub-pixels located on both sides of the internal black matrix having a relatively large width therebetween. The luminance deviation can be minimized. Accordingly, it is possible to prevent a band pattern from being recognized due to a luminance deviation.

1A is a diagram for explaining the light leakage phenomenon of a curved display device according to the prior art of the present invention, and FIG. 1B is a diagram for explaining the band pattern staining phenomenon of the curved display device according to the prior art of the present invention.
2 is a block diagram showing a curved display device according to the present invention.
FIG. 3 is a diagram for explaining each sub-pixel of the curved display panel shown in FIG. 2 .
FIG. 4 is a plan view illustrating a black matrix of the curved display panel shown in FIG. 2 .
FIG. 5 is a diagram for explaining a luminance relationship adjusted according to a line width in the black matrix shown in FIG. 4 .
FIG. 6 is a block diagram for explaining the configuration of an image processing unit shown in FIG. 2 .
FIG. 7 is a plan view illustrating another embodiment of the black matrix shown in FIG. 4 .
8 is a plan view illustrating another embodiment of sub-pixel arrangement of the curved display panel according to the present invention.
FIG. 9 is a diagram for explaining luminance weights applied according to the arrangement of sub-pixels shown in FIG. 8 .

Prior to the description of the embodiments of the present invention, a deterioration in image quality of a curved display device according to the prior art of the present invention will be first described as an example.

1A is a diagram for explaining the light leakage phenomenon of a curved display device according to the prior art of the present invention, and FIG. 1B is a diagram for explaining the band pattern staining phenomenon of the curved display device according to the prior art of the present invention.

As shown in FIG. 1A , the length of an arc corresponding to the length of the surface of the upper substrate 11 of the curved display panel is smaller than the length of the arc corresponding to the length of the surface of the lower substrate 1 . In this case, the data line 20 and the black matrix 30 located in the central region of the curved display panel completely overlap each other. However, since the data lines 20 and the black matrix 30 partially overlap or do not overlap, except for the central region of the curved display panel, there is a problem in that light leakage occurs.

In order to solve this problem, as shown in FIG. 1B, the line width Wc of the black matrix 30 overlapping the data line 20 located in the central area of the curved display panel is longer than the line width Wc overlapping the rest of the data line 20. Light leakage can be prevented by forming the line width Wp of the black matrix 30 to be wide.

In this case, the distances of left and right adjacent sub-pixels with the black matrix 30 located in the central region of the curved display panel are closer. Accordingly, as shown in FIG. 1B, overlapping luminance between adjacent sub-pixels with the data line 20 located in the central area of the curved display panel and the overlapping black matrix 30 interposed therebetween is larger than that of other areas, as shown in FIG. 1B. The luminance of adjacent sub-pixels with the black matrix 30 located in the area is higher than that of other sub-pixels, so that a band pattern is recognized.

In order to solve these problems of the prior art, the curved display device according to the present invention provides a method of improving image quality by compensating for the luminance of sub-pixels according to the line width of the black matrix.

2 is a block diagram showing a curved display device according to the present invention.

The curved display device illustrated in FIG. 2 includes a curved display panel 100 , a data driver 108 , a scan driver 106 , a timing controller 110 and an image processor 120 . Here, the timing controller 110 , the data driver 108 , and the scan driver 106 may be expressed as a display driver that drives the curved display panel 100 .

The timing controller 110 uses a plurality of synchronization signals input from the image processing unit 120, that is, a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a data enable signal, and a dot clock to control the operation of the data driver 108. A data control signal (DCS) for controlling the driving timing and a scan control signal (SCS) for controlling the driving timing of the scan driver 106 are generated. The timing controller 110 outputs the generated data control signal DCS and scan control signal SCS to the data driver 108 and scan driver 106, respectively. The data control signal DCS includes a source start pulse and source sampling clock for controlling the latch of the data signal, a polarity control signal for controlling the polarity of the data signal, and a source output enable signal for controlling the output period of the data signal. include The scan control signal SCS includes a scan start pulse and a scan shift clock for controlling scanning of the scan signal, and a scan output enable signal for controlling an output period of the scan signal.

The scan driver 106 sequentially drives the scan lines SL of the display panel 100 in response to a scan control signal from the timing controller 110 . The scan driver 106 supplies a scan pulse of a high state for each scan period of each scan line SL, and supplies a scan pulse of a low state during the remaining period in which the scan line SL is driven.

The data driver 108 converts the digital data DATA from the timing controller 110 into an analog data voltage in response to the data control signal DCS from the timing controller 110 so that each scan line SL is driven. is supplied to the data line (DL) each time.

The curved display panel 100 displays an image through unit pixels arranged in a matrix form. As shown in FIG. 3, the unit pixel is composed of red (R), green (G), and blue (B) sub-pixels, or red (R), green (G), blue (B), and white (W) sub-pixels. It is composed of fire. A liquid crystal display panel and an organic light emitting display panel may be used as the curved display panel 100, and an organic light emitting display panel will be described as an example in the present invention.

As shown in FIG. 4 , the curved display panel 100 is divided into two active regions in which a plurality of sub-pixels are disposed.

As shown in FIG. 3 , each sub-pixel disposed in the light emitting area of the active areas includes an organic light emitting diode (OLED) emitting light according to a data signal of an input image and a pixel circuit driving the organic light emitting diode (OLED). to provide The pixel driving circuit supplies a data current corresponding to the data signal supplied to the data line DL to the organic light emitting diode OLED in response to the scan signal supplied to the scan line SL. To this end, the pixel driving circuit includes a switching transistor Tr_S, a driving transistor Tr_D, and a capacitor C. The switching transistor Tr_S is switched according to the scan signal supplied to the scan line SL and supplies the data signal supplied to the data line DL to the driving transistor Tr_D. The driving transistor Tr_D is switched according to the data signal supplied from the switching transistor Tr_S to control current flowing from the high potential power supply VDD to the organic light emitting diode OLED. The capacitor C is connected between the gate terminal of the driving transistor Tr_D and the OLED, stores a voltage corresponding to a data signal supplied to the gate terminal of the driving transistor Tr_S, and uses the stored voltage as the driving transistor. The turn-on state of (Tr_D) is kept constant for one frame. Here, the configuration of the pixel driving circuit shown in FIG. 3 is only an exemplary embodiment and is not limited thereto.

The organic light emitting diode OLED is electrically connected between the source terminal of the driving transistor Tr_D and the low potential power supply VSS, and emits light by a current corresponding to a data signal supplied from the driving transistor Tr_D. To this end, the organic light emitting diode OLED includes an anode electrode connected to the source terminal of the driving transistor Tr_D, an organic layer formed on the anode electrode, and a cathode electrode formed on the organic layer. Here, the organic layer may include a hole injection layer/hole transport layer/emission layer/electron transport layer/electron injection layer, and the like.

Accordingly, each of the red (R), green (G), and blue (B) sub-pixels flows from the high-potential power supply VDD to the organic light emitting diode OLED by using the switching of the driving transistor Tr_D according to the data signal. The light emitting layer of the organic light emitting diode (OLED) emits light by controlling the magnitude of the current.

A boundary black matrix (BMb) is disposed in the center of the curved display panel 100, which is a boundary between two active regions of the curved display panel 100, and an internal black matrix (BMi) is disposed in the active regions. do. The black matrices BMb and BMi overlap with the scan lines SL and data lines DL, divide each sub-pixel area, and prevent light interference and light leakage between adjacent sub-pixel areas.

The boundary black matrix BMb and the internal black matrix BMi are formed to have different widths to prevent light leakage. That is, the width W2 of the boundary black matrix BMb is smaller than the width W1 of the internal black matrix BMi as shown in FIGS. 4 and 5 . Accordingly, the distance between the border sub-pixels SPb adjacent to the left and right with the border black matrix BMb interposed therebetween is close, so that the luminance of the border sub-pixels SPb is higher than that of the other internal sub-pixels SPi, resulting in a band pattern. A perceived phenomenon occurs.

In order to solve this problem, in the present invention, as shown in FIG. 5 , the luminance of adjacent boundary sub-pixels SPb with the boundary black matrix BMb interposed therebetween is converted into internal sub-pixels SPi through the image processing unit 120. It is possible to minimize the occurrence of luminance deviation by lowering the luminance of the luminance by a predetermined level.

The image processor 120 processes input image data supplied from the host computer and supplies the image data to the timing controller 110 . The image processing unit 120 may be built into the timing controller 110 and integrated into a single IC together with the timing controller 110, disposed between the timing controller 110 and a host computer (not shown), or a timing controller ( 110) and the data driver 108.

The image processing unit 120 adjusts the luminance of image data to be supplied to sub-pixels located in the active regions according to the line width of at least one of the boundary black matrix BMb and the internal black matrix BMi. That is, the image processing unit 120 lowers the luminance of image data to be supplied to the border sub-pixels SPb and outputs the lowered luminance to the timing controller 110 . To this end, the image processor 120 includes a data classifier 122, a luminance extractor 124, a luminance corrector 126, and a data corrector 128, as shown in FIG.

The data classification unit 122 divides the input image data into boundary image data to be supplied to the left and right adjacent boundary sub-pixels SPb with the boundary black matrix BMb interposed therebetween, and internal image data to be supplied to the internal sub-pixel SPi. classify as data. The classified internal image data is transmitted to the timing controller 110 as it is without data modulation, and the classified boundary image data is transmitted to the luminance extractor 124 .

The luminance extractor 124 calculates luminance data and color difference data from the input boundary image data. The color difference data of the calculated boundary image data is transmitted to the data correction unit 128, and the luminance data of the calculated boundary image data is transmitted to the luminance correction unit 126.

The luminance correction unit 126 multiplies the luminance data (Pcl, Pcr) of the input boundary image data by the luminance weight as shown in Equations 1 and 2 and applies a gamma value suitable for each sub-pixel to thereby apply low luminance data (Pcl', Pcr'). ) to create

In Equation 1, Pcl is luminance data of the border image data to be supplied to the border sub-pixel SPb located on the left side of the border black matrix BMb, and in Equation 2, Pcr(m,n) represents the border black matrix This is luminance data of border image data to be supplied to the border sub-pixel SPb located on the right side of (BMb). Further, in Equations 1 and 2, when the luminance compensator 126 generates low luminance data, α and β are luminance weights having a value smaller than 1, and when the luminance compensator 126 generates high luminance data. , α and β are luminance weights with values greater than 1.

At this time, the luminance weights (α, β) are determined by a function proportional to the width of a black matrix positioned between sub-pixels. For example, when the width W2 of the border black matrix BMb is smaller than the width W1 of the internal black matrix BMi, the border sub-pixel SPb is supplied with the border black matrix BMb interposed therebetween. Luminance weights (α, β) to be applied to boundary data to be applied are set to values smaller than 1. Further, when the width W2 of the boundary black matrix BMb is greater than the width W1 of the internal black matrix BMi, the boundary to be supplied to the adjacent boundary sub-pixel SPb with the boundary black matrix BMb interposed therebetween Luminance weights (α, β) to be applied to the image data are set to a value greater than 1.

In addition, when the emission areas or widths of adjacent border sub-pixels SPb with the border black matrix BMb interposed therebetween are the same, the border sub-pixels SPb located on the left and right sides of the border black matrix BMb The luminance weights (α, β) to be applied to boundary image data to be supplied to are set to be equal to a value smaller than 1. And, when the emission areas or widths of the adjacent border sub-pixels SPb with the border black matrix BMb interposed therebetween are different, the border sub-pixels SPb located on the left and right sides of the border black matrix BMb Luminance weights (α, β) to be applied to boundary image data to be supplied are set to different values smaller than 1. At this time, the luminance weight is set to be in inverse proportion to the area (width) of adjacent border sub-pixels with the border black matrix BMb interposed therebetween. When the width of the border sub-pixel SPb located on the left side of the border black matrix BMb is smaller than the width of the border sub-pixel SPb located on the right side of the border black matrix BMb, the luminance weight applied to the left border sub-pixel SPb is It is set to be greater than the luminance weight applied to the border sub-pixel SPb.

Accordingly, the luminance compensator 126 may lower luminance data of an adjacent border sub-pixel SPb than luminance data of internal sub-pixels SPi with the border black matrix BMb interposed therebetween.

The data correction unit 128 calculates the corrected boundary image data through the luminance data and color difference data converted by the luminance correction unit 126 . The calculated boundary image data is output to the timing controller 110 together with the internal image data classified by the data classification unit 122 .

As such, the curved display device according to the present invention can minimize the luminance deviation of the boundary sub-pixels SPb located on both sides with the boundary black matrix BMb having a relatively small width interposed therebetween.

Meanwhile, in the first embodiment of the present invention, the curved display panel is divided into two active regions as an example, but as shown in FIG. 7 , it may be divided into two or more active regions.

8 is a diagram illustrating sub-pixels disposed in each active area of a curved display panel according to a second embodiment of the present invention.

The curved display device according to the second embodiment of the present invention shown in FIG. 8 has sub-pixels disposed in the active area in contrast to the curved display device shown in FIG. 4 in which the inner black matrix disposed in the active area has the same line width. Each has the same components except for the different line widths of the black matrix. Accordingly, a detailed description of the same configuration element will be omitted.

Unit pixels disposed in each active area of the curved display panel 100 shown in FIG. 8 are formed in a quad structure using four sub-pixels. Sub-pixels implementing different colors are sequentially arranged on the first vertical line of the curved display panel 100, and the sub-pixels arranged on the first vertical line move downward from the first vertical line to the last vertical line. They are arranged so that they are shifted by two columns. Accordingly, white (W) sub-pixels, blue (B) sub-pixels, green (G) sub-pixels, and red (R) sub-pixels are repeatedly arranged in the order of odd-numbered vertical lines, and odd-numbered vertical lines are arranged on even-numbered vertical lines. The sub-pixels are arranged in the order of a green (G) sub-pixel, a red (R) sub-pixel, a white (W) sub-pixel, and a blue (B) sub-pixel so that the sub-pixels arranged in are shifted downward by two columns.

At this time, the width of the internal black matrix (BMi) between vertically adjacent sub-pixels disposed in each active area is constant, but the width of the internal black matrix (BMi) between horizontally adjacent sub-pixels is different for each sub-pixel. .

Accordingly, in the curved display device according to the second embodiment of the present invention, not only the area (width) of the border sub-pixels varies by the line width of the border black matrix (BMb), but also the line width of the internal black matrix (BMi). The luminance weight is changed according to the area (width) of the internal sub-pixel.

That is, the luminance compensator 126 determines the area (width) of the sub-pixel (SPi) located on one side with the internal black matrix (BMi) in between and the area (width) of the sub-pixel located on the other side. As shown in FIG. 9, different luminance weights that are inversely proportional to the area (width) of the sub-pixel SPi are applied. For example, when the area (width) of a sub-pixel located on one side with the internal black matrix BMi interposed therebetween is larger (smaller) than the area (width) of a sub-pixel located on the other side, the sub-pixel located on one side A smaller (larger) luminance weight α to be applied to image data to be supplied to the sub-pixel SPi located on the other side than the luminance weight β to be applied to image data to be supplied to (SPi) is applied. Further, when the area (width) of the sub-pixel located on one side with the internal black matrix BMi interposed therebetween and the area (width) of the sub-pixel SPi located on the other side are the same, the sub-pixels located on one side and the other side Luminance weights α to be applied to image data to be supplied to (SPi) are equally applied.

As described above, the curved display device according to the second embodiment of the present invention controls the luminance of the boundary sub-pixels SPb located on both sides with the boundary black matrix BMb having a relatively small width, The luminance deviation can be minimized by lowering the luminance of the internal sub-pixels SPi positioned on both sides with the large internal black matrix BMi interposed therebetween. Further, in the curved display device according to the second embodiment of the present invention, when the areas (widths) of the inner sub-pixels located on both sides with the inner black matrix interposed therebetween are different, the luminance of the inner sub-pixels having a large area (width) The luminance deviation can be minimized by lowering the luminance of the internal sub-pixel having a small area (width).

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.

100: curved display panel 106: scan driver
108: data driver 110: timing controller
120: image processing unit

Claims (9)

a curved display panel divided into at least two active regions, wherein at least one boundary black matrix located at a boundary between the active regions and an internal black matrix located within the active regions have different line widths; and
an image processing unit adjusting luminance of image data to be supplied to sub-pixels located in the active regions according to a line width of at least one of the boundary black matrix and the internal black matrix; including,
The sub-pixels include boundary sub-pixels positioned on both sides with the boundary black matrix interposed therebetween and internal sub-pixels positioned on both sides with the internal black matrix interposed therebetween;
The image processing unit adjusts the luminance of image data to be supplied to the border sub-pixels according to the line width of the boundary black matrix, and adjusts the luminance of image data to be supplied to the internal sub-pixels according to the line width of the internal black matrix. A curved display device that According to claim 1,
The at least one boundary black matrix is disposed in the center of the curved display panel. According to claim 1,
The curved display device of claim 1 , wherein a line width of the boundary black matrix is smaller than a line width of the internal black matrix. According to claim 3,
The image processing unit multiplies luminance data of image data to be supplied to the adjacent border sub-pixels with the border black matrix interposed therebetween by a luminance weight to lower luminance of the border sub-pixels. According to claim 4,
The curved display device of claim 1 , wherein line widths of adjacent border sub-pixels with the border black matrix interposed therebetween are the same, and luminance weights applied to respective sub-pixels located on one side and the other side of the border black matrix are the same. According to claim 4,
The line widths of the border sub-pixels adjacent to each other with the border black matrix interposed therebetween are different, and the luminance weights applied to the border sub-pixels located on one side and the other side of the border black matrix are different from each other. According to claim 6,
The luminance weight is set to be inversely proportional to the line widths of the boundary sub-pixels. According to claim 4,
Line widths of the adjacent internal sub-pixels with the internal black matrix interposed therebetween are different, and luminance weights applied to each of the internal sub-pixels located on one side and the other side of the internal black matrix are different from each other. According to claim 8,
The luminance weight is set to be in inverse proportion to line widths of the internal sub-pixels.

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