Display device and method of operation thereof

Abstract

The display device includes a display panel and a driving circuit that receives an input image signal and provides an output image signal to the display panel, wherein the driving circuit includes an edge and slope detector that detects an edge of the input image signal and calculates an angle between the edge and a virtual line parallel to a first direction, a weight calculator that calculates a weight based on the edge and angle, and a rendering unit that compensates the input image signal based on the weight and outputs the output image signal, wherein the weight is calculated by an arithmetic operation of the edge and the angle.

Description

Technology Field

[0001] The present invention relates to a display device. Background Technology

[0002] The display device comprises a display panel including a plurality of pixels. Each of the plurality of pixels can provide light of any one of various colors, such as red light, green light, and blue light.

[0003] A desired image can be displayed by adjusting the light emission intensity of each of the multiple pixels.

[0004] The size and arrangement method of each of the multiple pixels can vary. The problem to be solved

[0005] The objective of the present invention is to provide a display device capable of preventing degradation of the quality of a displayed image due to a pixel arrangement method, and a method of operating the same. means of solving the problem

[0006] According to one feature of the present invention for achieving such an objective, a display device includes a display panel and a driving circuit that receives an input image signal and provides an output image signal corresponding to the input image signal to the display panel. The driving circuit includes an edge and slope detector that detects an edge of the input image signal and calculates an angle between the edge and a virtual line parallel to a first direction, a weight calculator that calculates a weight based on the edge and the angle, and a rendering unit that compensates the input image signal based on the weight and outputs the output image signal, wherein the weight is calculated by an arithmetic operation of the edge and the angle.

[0007] In one embodiment, the edge and slope detector may calculate a first edge by convolution operation of the input image signal and a first filter, calculate a second edge by convolution operation of the input image signal and a second filter, and output the edge based on the first edge and the second edge.

[0008] In one embodiment, the edge is a mathematical formula It is calculated by, where EG is the edge, EG_x is the first edge, and EG_y is the second edge.

[0009] In one embodiment, the larger the value of the edge, the larger the weight may be, and the smaller the angle, the larger the weight may be.

[0010] In one embodiment, the edge is a mathematical formula It is calculated by, where EG is the edge, EG_x is the first edge, and EG_y is the second edge.

[0011] In one embodiment, the first filter includes a determinant gx, and the second filter includes a determinant gy, and 일 수 있다.

[0012] In one embodiment, the weight calculator may include a first lookup table that stores a first compensation value corresponding to the edge and a second lookup table that stores a second compensation value corresponding to the angle.

[0013] In one embodiment, the weight is calculated by the mathematical formula W=(LUT_EG×LUT_AG), where W is the weight, LUT_EG is the first compensation value, and LUT_AG is the second compensation value.

[0014] In one embodiment, the weight is calculated by the mathematical formula WQ=(LUT_EG×LUT_AG)×G_q, where WQ is the weight, LUT_EG is the first compensation value, LUT_AG is the second compensation value, and G_q is the panel compensation value.

[0015] In one embodiment, the display panel may include first to third pixels arranged in first to third pixel regions.

[0016] In one embodiment, the first pixel area is placed in a first pixel row, and the second pixel area and the third pixel area may be placed in a second pixel row adjacent to the first pixel row.

[0017] In one embodiment, the input image signal may include first to third color signals corresponding to each of the first to third pixels.

[0018] In one embodiment, the rendering unit can render the first color signal using a first rendering filter including the weight, render the second color signal using a second rendering filter including the weight, and render the third color signal using a third rendering filter including the weight.

[0019] A method of operation of a display device according to one feature of the present invention comprises: a step of detecting an edge of an input image signal; a step of calculating an angle between the edge and a virtual line parallel to a first direction; a weight calculator that calculates a weight based on the edge and the angle; and a rendering unit that compensates the input image signal based on the weight and outputs an output image signal, wherein the weight is calculated by an arithmetic operation of the edge and the angle.

[0020] In one embodiment, the step of detecting the edge may include calculating a first edge by convolution operation of the input image signal and a first filter, calculating a second edge by convolution operation of the input image signal and a second filter, and outputting the edge based on the first edge and the second edge.

[0021] In one embodiment, the edge is a mathematical formula It is calculated by, where EG is the edge, EG_x is the first edge, and EG_y is the second edge.

[0022] In one embodiment, the smaller the angle, the greater the weight, and the larger the edge value, the greater the weight.

[0023] In one embodiment, the edge is a mathematical formula It is calculated by,

[0024] EG is the edge, EG_x is the first edge, and EG_y is the second edge.

[0025] In one embodiment, the weight is calculated by the mathematical formula WQ=(LUT_EG×LUT_AG)×G_q, where WQ is the weight, LUT_EG is a first compensation value corresponding to the edge, LUT_AG is a second compensation value corresponding to the angle, and G_q is a panel compensation value.

[0026] In one embodiment, the display panel includes first to third pixels each disposed in first to third pixel regions, the first pixel region is disposed in a first pixel row, and the second pixel region and the third pixel region may be disposed in a second pixel row adjacent to the first pixel row. Effects of the invention

[0027] A display device having such a configuration detects edges and edge slopes of an input image signal. If the input image signal has edges and edge slopes that can degrade the quality of the display image, the input image signal can be corrected and an output image signal can be provided to the display panel. Therefore, it is possible to prevent the display quality from degrading in a display device having a specific pixel array. Brief explanation of the drawing

[0028] FIG. 1 is a perspective view of a display device according to an embodiment of the present invention. FIG. 2 is a block diagram of a display device according to an embodiment of the present invention. FIG. 3 is a plan view of a display area of ​​a display panel according to an embodiment of the present invention. FIG. 4 illustrates an exemplary image pattern displayed on a display panel. FIG. 5 is a block diagram showing the configuration of a driving controller according to an embodiment of the present invention. FIG. 6a illustrates exemplary test images for testing visibility according to the edges and tilt of an image. FIG. 6b is a drawing showing an enlarged view of a test image. FIG. 7 illustrates exemplary evaluation scores of the test images shown in FIG. 6. FIG. 8 is a graph showing an example of normalizing the compensation value for an edge detected by the edge and tilt detector shown in FIG. 5. FIG. 9 is a graph showing an example of normalizing the compensation value for an angle detected by the edge and tilt detector shown in FIG. 5. FIG. 10 is a graph showing the visibility test results shown in FIG. 7. FIG. 11 is an edge-angle graph shown in FIG. 10 Upsampling is shown as an example. FIG. 12 shows the product of edges and angles when the edges and angles detected by the edge and tilt detector shown in FIG. 5 are normalized. FIG. 13 shows the difference between edges and angles when the edges and angles detected by the edge and tilt detector shown in FIG. 5 are normalized. FIG. 14a, FIG. 14b, and FIG. 14c show the rendering filters of the rendering unit shown in FIG. 5 as examples. FIG. 15a is a test pattern of an input image signal. FIG. 15b and FIG. 15c show the test pattern displayed on a display panel as an example. FIG. 16 is a flowchart of a method of operation of a display device according to an embodiment of the present invention. Specific details for implementing the invention

[0029] In this specification, where a component (or region, layer, part, etc.) is described as being "on," "connected," or "combined" with another component, it means that it may be directly placed / connected / combined with the other component, or that a third component may be placed between them.

[0030] Identical reference numerals denote identical components. Additionally, in the drawings, the thicknesses, proportions, and dimensions of the components are exaggerated for the effective illustration of the technical content. "And / or" includes all one or more combinations that the associated components may define.

[0031] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0032] Additionally, terms such as "below," "lower side," "above," and "upper side" are used to describe the relationships between the components depicted in the drawings. These terms are relative concepts and are described based on the directions indicated in the drawings.

[0033] Terms such as "include" or "have" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0034] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Furthermore, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an overly ideal or overly formal sense unless explicitly defined herein.

[0035] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0036] FIG. 1 is a perspective view of a display device according to one embodiment of the present invention.

[0037] Referring to FIG. 1, the display device (DD) may be a device that is activated according to an electrical signal. The display device (DD) according to the present invention may be a large display device such as a television or monitor, as well as a medium-sized display device such as a mobile phone, tablet, laptop, car navigation system, or game console. These are merely examples, and it is understood that other types of display devices may be included without departing from the concept of the present invention.

[0038] The display device (DD) has a rectangular shape having a long side in the first direction (DR1) and a short side in the second direction (DR2) that intersects the first direction (DR1). However, the shape of the display device (DD) is not limited to this, and a display device (DD) of various shapes may be provided. The display device (DD) can display an image (IM) toward the third direction (DR3) on a display surface (IS) parallel to each of the first direction (DR1) and the second direction (DR2). The display surface (IS) on which the image (IM) is displayed may correspond to the front surface of the display device (DD).

[0039] In this embodiment, the front (or top) and back (or bottom) surfaces of each member are defined based on the direction in which the image (IM) is displayed. The front and back surfaces are opposed to each other in a third direction (DR3), and the normal direction of each of the front and back surfaces may be parallel to the third direction (DR3).

[0040] The distance between the front and back surfaces in the third direction (DR3) may correspond to the thickness of the display device (DD) in the third direction (DR3). Meanwhile, the directions indicated by the first to third directions (DR1, DR2, DR3) can be converted to other directions as relative concepts.

[0041] A display device (DD) can detect external input applied from the outside. External input may include various forms of input provided from outside the display device (DD). A display device (DD) according to one embodiment of the present invention can detect external input from a user applied from the outside. The user's external input may be any one of various forms of external input, such as a part of the user's body, light, heat, gaze, or pressure, or a combination thereof. Additionally, depending on the structure of the display device (DD), the display device (DD) may detect external input from a user applied to the side or back of the display device (DD), and is not limited to any one embodiment. As an example of the present invention, external input may include input by an input device (e.g., a stylus pen, an active pen, a touch pen, an electronic pen, an e-pen, etc.).

[0042] The display surface (IS) of the display device (DD) may be divided into a display area (DA) and a non-display area (NDA). The display area (DA) may be an area where an image (IM) is displayed. The user perceives the image (IM) through the display area (DA). In this embodiment, the display area (DA) is depicted as a square shape with rounded vertices. However, this is illustrated as an example, and the display area (DA) may have various shapes and is not limited to any one embodiment.

[0043] A non-display area (NDA) is adjacent to a display area (DA). The non-display area (NDA) may have a predetermined color. The non-display area (NDA) may surround the display area (DA). Accordingly, the shape of the display area (DA) may be substantially defined by the non-display area (NDA). However, this is illustrated as an example, and the non-display area (NDA) may be placed adjacent to only one side of the display area (DA) or may be omitted. A display device (DD) according to an embodiment of the present invention may include various embodiments and is not limited to any one embodiment.

[0044] FIG. 2 is a block diagram of a display device according to one embodiment of the present invention.

[0045] Referring to FIG. 2, the display device (DD) includes a driving controller (100), a data driving circuit (200), and a display panel (DP).

[0046] The driving controller (100) receives an input video signal (RGB) and a control signal (CTRL). The driving controller (100) generates an output video signal (DS) by converting the data format of the input video signal (RGB) to match the interface specifications with the data driving circuit (200). The driving controller (100) outputs a scan control signal (SCS) and a data control signal (DCS).

[0047] The data driving circuit (200) receives a data control signal (DCS) and an output video signal (DS) from the driving controller (100). The data driving circuit (200) converts the output video signal (DS) into data signals and outputs the data signals to a plurality of data lines (DL1-DLm) described later. The data signals are analog voltages corresponding to the grayscale levels of the output video signal (DS).

[0048] A display panel (DP) according to one embodiment of the present invention may be a light-emitting display panel. For example, the display panel (DP) may be an organic light-emitting display panel, an inorganic light-emitting display panel, or a quantum dot light-emitting display panel. The light-emitting layer of an organic light-emitting display panel may include an organic light-emitting material. The light-emitting layer of an inorganic light-emitting display panel may include an inorganic light-emitting material. The light-emitting layer of a quantum dot light-emitting display panel may include quantum dots and quantum rods, etc. Hereinafter, in this embodiment, the display panel (DP) is described as an organic light-emitting display panel.

[0049] The display panel (DP) includes scan lines (GL1-GLn), data lines (DL1-DLm), and pixels (PX11-PXnm). The display panel (DP) may further include a scan driving circuit (300). In one embodiment, the scan driving circuit (300) is arranged on a first side of the display panel (DP). The scan lines (GL1-GLn) extend from the scan driving circuit (300) in a first direction (DR1).

[0050] The driving controller (100), data driving circuit (200), and scan driving circuit (300) may be driving circuits for providing data signals corresponding to the input image signal (RGB) of the display panel (DP) to pixels (PX11-PXnm).

[0051] The pixels (PX11-PXnm) are placed in the display area (DA) of the display panel (DP), and the scan driving circuit (300) can be placed in the non-display area (NDA).

[0052] Scan lines (GL1-GLn) extend from the scan driving circuit (300) in a first direction (DR1) and are arranged spaced apart from each other in a second direction (DR2). Data lines (DL1-DLm) extend from the data driving circuit (200) in a second direction (DR2) and are arranged spaced apart from each other in a first direction (DR1).

[0053] Each of the plurality of pixels (PX11-PXnm) may be connected to a corresponding scan line among the scan lines (GL1-GLn) and may be connected to a corresponding data line among the data lines (DL1-DLm). Although FIG. 2 is illustrated as having one pixel (PX) connected to one scan line, the present invention is not limited thereto. One pixel (PX) may be electrically connected to two or more scan lines.

[0054] Each of the plurality of pixels (PX11-PXnm) may include a light-emitting element (not shown) and a pixel circuit portion (not shown) that controls the light emission of the light-emitting element. In one embodiment, the light-emitting element may be an organic light-emitting diode. However, the present invention is not limited thereto.

[0055] The scan driving circuit (300) receives a scan control signal (SCS) from the driving controller (100). The scan driving circuit (300) can output scan signals to scan lines (GL1-GLn) in response to the scan control signal (SCS). In one embodiment, the scan driving circuit (300) can be formed by the same process as the pixel circuit within the pixel.

[0056] FIG. 3 is a plan view of the display area of ​​a display panel according to one embodiment of the present invention.

[0057] Referring to FIG. 3, first to third pixel regions (PXA_R, PXA_G, PXA_B) may be arranged in the display area (DA) of the display panel (DP, see FIG. 2).

[0058] In one embodiment, the first to third pixel regions (PXA_R, PXA_G, PXA_B) may be repeatedly arranged over the entire display area (DA). A surrounding region (NPXA) is arranged around the first to third pixel regions (PXA_R, PXA_G, PXA_B). The surrounding region (NPXA) sets the boundaries of the first to third pixel regions (PXA_R, PXA_G, PXA_B) and prevents color mixing between the first to third pixel regions (PXA_R, PXA_G, PXA_B).

[0059] In this embodiment, first to third pixel regions (PXA_R, PXA_G, PXA_B) with different planar areas are illustrated as examples, but are not limited thereto. At least two of the first to third pixel regions (PXA_R, PXA_G, PXA_B) may have the same area. FIG. 3 illustrates first to third pixel regions (PXA_R, PXA_G, PXA_B) as planar polygons, but is not limited thereto. In a planar plane, the first to third pixel regions (PXA_R, PXA_G, PXA_B) may have polygonal shapes of other shapes, such as rectangles, rhombuses, pentagons, etc.

[0060] In one embodiment, a first pixel area (PXA_R) may provide a first color light (e.g., red light), a second pixel area (PXA_G) may provide a second color light (e.g., green light), and a third pixel area (PXA_B) may provide a third color light (e.g., blue light).

[0061] The first to third pixel regions (PXA_R, PXA_G, PXA_B) may correspond to the first to third pixels among the pixels (PX11-PXnm), respectively. The first to third pixels may be red, green, and blue pixels.

[0062] The second pixel area (PXA_G) is placed in the first pixel row (PXL1), and the first pixel area (PXA_R) and the third pixel area (PXA_B) are placed in the second pixel row (PXL2) adjacent to the first pixel row (PXL1). With such a pixel arrangement, color fringing can be observed by the user.

[0063] Figure 4 shows an exemplary image pattern displayed on a display panel.

[0064] Referring to FIG. 4, the image (IMG) displayed on the display panel (DP) includes a background image with black gradations and a box image containing white gradations. Green light is displayed at the boundary area (A1) where the background image and the box image meet, and magenta light can be displayed at the boundary area (A2).

[0065] As such, the display of unwanted images in boundary regions (A1, A2) is due to the arrangement of the first to third pixel regions (PXA_R, PXA_G, PXA_B) shown in FIG. 3.

[0066] Since a second pixel area (PXA_G) providing green light is placed in the first pixel row (PXL1), green light can be seen in the boundary area (A1). Additionally, since a first pixel area (PXA_R) providing red light and a third pixel area (PXA_B) providing blue light are placed in the second pixel row (PXL2), magenta light can be seen in the boundary area (A2).

[0068] FIG. 5 is a block diagram showing the configuration of a driving controller (100) according to one embodiment of the present invention.

[0069] Referring to FIG. 5, the driving controller (100) includes an edge and tilt detector (110), a weight calculator (120), a first gamma corrector (130), a rendering unit (140), and a second gamma corrector (150).

[0070] The edge and slope detector (110) detects edges (or boundaries) of the input image signal (RGB) and calculates the slope of the detected edges.

[0071] When the difference value of the input image signals (RGB) corresponding to two adjacent pixels (PX11-PXnm) (see FIG. 2) is greater than a reference value, it can be determined as an edge of the input image signal (RGB). The edge and gradient detector (110) can detect edges through a convolution operation of the input image signal (RGB) and a kxk filter (or mask) (where k is a positive integer).

[0072] In one embodiment, the size of the filter may be 3 x 3.

[0073] The first edge (EG_x) in the first direction (DR1, see FIG. 2) (or horizontal direction) of the input image signal (RGB) can be calculated by Equation 1.

[0074] [Mathematical Formula 1]

[0075] EG_x = RGB * gx

[0076] In mathematical formula 1, gx is the horizontal filter.

[0077] That is, the first edge (EG_x) in the horizontal direction of the input image signal (RGB) can be calculated by the convolution operation of the input image signal (RGB) and the horizontal filter (gx).

[0078] The second edge (EG_y) in the second direction (DR2, see FIG. 2) (or vertical direction) of the input image signal (RGB) can be calculated by Equation 2.

[0079] [Mathematical Formula 2]

[0080] EG_y = RGB * gy

[0081] In mathematical formula 2, gy is a vertical filter.

[0082] That is, the second edge (EG_y) in the vertical direction of the input image signal (RGB) can be calculated by the convolution operation of the input image signal (RGB) and the vertical filter (gy).

[0083] In one embodiment, the horizontal filter (gx) and the vertical filter (gy) are respectively It could be.

[0084] In one embodiment, the horizontal filter (gx) and the vertical filter (gy) are respectively It could be.

[0085] In one embodiment, the horizontal filter (gx) and the vertical filter (gy) are respectively It could be.

[0086] The size and value of the horizontal filter (gx) and the vertical filter (gy) are not limited to the examples above.

[0087] The edge (EG) of the input image signal (RGB) can be calculated based on the first edge (EG_x) in the horizontal direction and the second edge (EG_y) in the vertical direction of the input image signal (RGB).

[0088] In one embodiment, the edge (EG) of the input image signal (RGB) can be calculated by Equation 3.

[0089] [Mathematical Formula 3]

[0090]

[0091] In one embodiment, the edge (EG) of the input image signal (RGB) can be calculated by Equation 4.

[0092] [Mathematical Formula 4]

[0093]

[0094] The angle (AG) between the edge (EG) of the input image signal (RGB) and a virtual line parallel to the first direction (DR1) (see FIG. 2) can be calculated by Equation 5.

[0095] [Mathematical Formula 5]

[0096]

[0097] This means that the larger the value of the edge (EG) of the input image signal (RGB) calculated by Equation 3 or Equation 4, and the smaller the angle (AG), the greater the edge intensity in the first direction (DR1). That is, when the edge (EG) of the input image signal (RGB) is large and the angle (AG) is small, color bleeding may occur in the boundary regions (A1, A2) shown in Fig. 4.

[0098] The weight calculator (120) calculates weights (WQ) based on the edges (EG) and angles (AG) of the input image signal (RGB) calculated by the edge and gradient detector (110). The weights (WQ) may be compensation values ​​for the input image signal (RGB).

[0099] The weight calculator (120) can store the compensation values ​​for each of the edge (EG) and angle (AG) in a lookup table. In one embodiment, when the first compensation value for the edge (EG) is denoted as LUT_EG and the second compensation value for the angle (AG) is denoted as LUT_AG, the weight (W) can be calculated by Equation 6.

[0100] [Mathematical Formula 6]

[0101]

[0102] The weight (W) is a value calculated by the arithmetic operation of the edge (EG) and the angle (AG). The weight calculator (120) calculates the weight (WQ) by multiplying the weight (W) by a gain (i.e., panel compensation value (G_q)) that takes into account the characteristics of the display panel (DP, see FIG. 2). The weight (WQ) can be calculated by Equation 7.

[0103] [Mathematical Formula 7]

[0104]

[0105] The first gamma corrector (130) receives an input image signal (RGB). The first gamma corrector (130) corrects the input image signal (RGB) to a first gamma characteristic and outputs a corrected image signal (RGB_C). In one embodiment, the first gamma corrector (130) can correct the input image signal (RGB) to a gamma 2.2 curve characteristic and output a corrected image signal (RGB_C).

[0106] The rendering unit (140) performs rendering based on the corrected image signal (RGB_C) and weights (WQ) and outputs the rendered image signal (RGB_R).

[0107] The second gamma corrector (150) receives a rendered image signal (RGB_R). The second gamma corrector (150) corrects the rendered image signal (RGB_R) to have a second gamma characteristic and outputs an output image signal (DS). In one embodiment, the second gamma corrector (150) can correct the rendered image signal (RGB_R) to a gamma 0.45 curve characteristic and output an output image signal (DS). In one embodiment, the output image signal (DS) may be a signal in which the degradation characteristic of the input image signal (RGB) is compensated based on a weight (WQ).

[0108] In one embodiment, the driving controller (100) may not include both the first gamma corrector (130) and the second gamma corrector (150). In the case where the first gamma corrector (130) and the second gamma corrector (150) are not included, the rendering unit (140) may compensate the input image signal (RGB) based on the input image signal (RGB) and the weight (WQ) and output the output image signal (DS).

[0109] In one embodiment, the drive controller (100) may not include either the first gamma corrector (130) and the second gamma corrector (150).

[0110] Figure 6a shows exemplary test images for testing visibility according to the edges and tilt of the image.

[0111] Figure 6b is a diagram showing an enlarged view of the test image (IMG10).

[0112] Referring to FIGS. 6a and 6b, each of the test images (IMG1-IMG10) includes edges (E1-E12).

[0113] Each of the edges (E1-E12) has a predetermined slope with respect to a virtual line (VL) parallel to the first direction (DR1).

[0114] The slope deviation between two adjacent edges (E1-E12) is 15 degrees. For example, the angle (θ) between edge (E1) and edge (E2) is 15 degrees.

[0115] Also, the difference in luminance between the test images (IMG1-IMG10), i.e., the edge intensity, is 10%. For example, when the luminance of the edges (E1-E12) of the test image (IMG10) is 100%, the luminance of the edges of the test image (IMG9) is 90%, the luminance of the edges of the test image (IMG8) is 80%, the luminance of the edges of the test image (IMG7) is 70%, and the luminance of the edges of the test image (IMG1) is 10%.

[0116] Figure 7 exemplarily shows the evaluation scores of the test images illustrated in Figure 6.

[0117] Referring to FIGS. 6 and FIGS. 7, test participants were shown test images (IMG1-IMG10) illustrated in FIGS. 6 and asked to assign a visibility score of 1.0 to 5.0 for the color fading phenomenon according to the edge tilt in each of the test images (IMG1-IMG10).

[0118] As shown in FIG. 7, it can be seen that the lower the slope, that is, when the edge is parallel to the first direction (DR1) and the higher the edge intensity, the better the color fading phenomenon is visible. The edge intensity may be the luminance of the edge.

[0119] FIG. 8 is a graph showing an example of normalizing a compensation value (LUT_EG) for an edge (EG) detected by the edge and slope detector (110) shown in FIG. 5.

[0120] FIG. 9 is a graph showing an example of normalizing a compensation value (LUT_AG) for an angle (AG) detected by the edge and slope detector (110) shown in FIG. 5.

[0121] Referring to FIGS. 7, 8, and 9, it can be seen that the compensation value (LUT_EG) for the detected edge (EG) and the compensation value (LUT_AG) for the angle (AG) are suitable for the visibility evaluation results. That is, the higher the brightness (or intensity of the edge) of the edge, the larger the compensation value (LUT_EG), and the smaller the slope of the edge, the larger the compensation value (LUT_AG).

[0122] Figure 10 is a graph showing the visibility test results illustrated in Figure 7. In Figure 10, the horizontal axis is the edge (EG) and the vertical axis is the angle (AG).

[0123] Figure 11 exemplarily shows an up-sampled edge (EG)-angle (AG) graph illustrated in Figure 10.

[0124] Since the test results shown in Fig. 7 were obtained in a limited test environment, upsampling them allows for the visualization characteristics of the color fading phenomenon according to the edge (EG) and angle (AG) as shown in Fig. 11.

[0125] FIG. 12 shows the product of the edge (EG) and angle (AG) (EG x AG) when the edge (EG) and angle (AG) detected by the edge and tilt detector (110) shown in FIG. 5 are normalized. It can be seen that the graph of the product of the edge (EG) and angle (AG) shown in FIG. 12 has a shape similar to the graph of the upsampling of the visibility test results shown in FIG. 11.

[0126] FIG. 13 shows the difference (EG - AG) between the edge (EG) and the angle (AG) when the edge (EG) and the angle (AG) detected by the edge and slope detector (110) shown in FIG. 5 are normalized. As shown in FIG. 13, the difference between the edge (EG) and the angle (AG) is close to 0.

[0128] FIGS. 14a, FIGS. 14b, and FIGS. 14c exemplarily show rendering filters of the rendering unit illustrated in FIG. 5.

[0129] FIG. 14a illustrates an exemplary first rendering filter (RF1) used for rendering a first color signal (referred to as R) among input image signals (RGB). The first color signal (R) may be a red color signal.

[0130] As shown in FIG. 3, since the first pixel area (PXA_R) is positioned at the bottom left, a weight (WQ) is placed as a rendering factor at coordinates (2, 1) and (3, 2) of the first rendering filter (RF1). 1-WQx2 is placed as a rendering factor at coordinates (2, 2) of the first rendering filter (RF1).

[0131] FIG. 14b illustrates an exemplary second rendering filter (RF2) used for rendering a second color signal (referred to as G) among the input image signals (RGB). The second color signal (G) may be a green color signal.

[0132] As shown in FIG. 3, since the second pixel area (PXA_G) is positioned at the top center, a weight (WQ) is placed as a rendering factor at the coordinates (1, 2) of the second rendering filter (RF2). At the coordinates (2, 2) of the second rendering filter (RF2), 1-WQx2 is placed as a rendering factor.

[0133] FIG. 14c illustrates an exemplary third rendering filter (RF3) used for rendering a third color signal (referred to as B) among the input image signals (RGB). The third color signal (B) may be a blue color signal.

[0134] As shown in FIG. 3, since the third pixel area (PXA_B) is positioned at the bottom right, a weight (WQ) is placed as a rendering factor at coordinates (2, 3) and (3, 2) of the third rendering filter (RF3). 1-WQx2 is placed as a rendering factor at coordinates (2, 2) of the third rendering filter (RF3).

[0135] The rendering unit (140) illustrated in FIG. 5 can perform a convolution operation between the first color signal (R) and the first rendering filter (RF1) among the input image signals (RGB), perform a convolution operation between the second color signal (G) and the second rendering filter (RF2), and perform a convolution operation between the third color signal (B) and the third rendering filter (RF3), and then output the rendered image signal (RGB_R).

[0136] Figure 15a is a test pattern (PTN1) of an input image signal (RGB).

[0137] Referring to FIG. 15a, the test pattern (PTN1) of the input image signal (RGB) includes a check pattern with alternating black and white gradations, and horizontal and vertical stripe patterns.

[0138] FIGS. 15b and FIGS. 15c exemplarily show test patterns (PTN2, PTN3) displayed on a display panel (DP).

[0139] When low-pass filtering is performed on the input image signal (RGB) without considering the edges and slopes of the input image signal (RGB), the test pattern (PTN2) shown in FIG. 15b can be displayed on the display panel (DP, see FIG. 2).

[0140] The test pattern (PTN1) shown in FIG. 15a includes black and white gradations, but the test pattern (PTN2) shown in FIG. 15b shows that the black and white gradations have been changed to magenta and gray gradations.

[0141] When rendering is performed on the input image signal (RGB) by taking into account the edges and slopes of the input image signal (RGB), the test pattern (PTN3) illustrated in FIG. 15c can be displayed on the display panel (DP, see FIG. 2).

[0142] The test pattern (PTN3) shown in FIG. 15c includes black and white gradations similar to the test pattern (PTN1) shown in FIG. 15a.

[0143] According to the present invention, which calculates weights (WQ) based on the edges and slopes of an input image signal (RGB) and renders using first to third rendering filters (RF1-RF3) (Figs. 14a to 14c) that include the weights (WQ), a test pattern (PTN3) similar to a test pattern (PTN1) can be displayed on a display panel (DP, see Fig. 2).

[0144] FIG. 16 is a flowchart of a method of operation of a display device according to one embodiment of the present invention.

[0145] For convenience of explanation, the operation method of the display device is described with reference to the driving controller shown in FIG. 5, but the present invention is not limited thereto. Additionally, redundant descriptions among the contents described with reference to FIG. 1 to FIG. 15c are omitted.

[0146] Referring to FIGS. 5 and FIGS. 16, the edge and slope detector (110) detects the edges of the input image signal (RGB) (step S100).

[0147] A first edge (EG_x) in the first direction (DR1, see FIG. 2) (or horizontal direction) of the input image signal (RGB) and a second edge (EG_y) in the second direction (DR2, see FIG. 2) (or vertical direction) of the input image signal (RGB) can be calculated, and the sum of the first edge (EG_x) and the second edge (EG_y) can be output as an edge (EG).

[0148] The edge and tilt detector (110) calculates the angle (AG) between the detected edge (EG) and a virtual line parallel to the first direction (DR1) (see FIG. 2) (step S110).

[0149] The weight calculator (120) calculates weights (WQ) based on the edges (EG) and angles (AG) of the input image signal (RGB) calculated by the edge and slope detector (110) (step S120).

[0150] The rendering unit (140) can perform rendering based on the input image signal (RGB) and weight (WQ) and output an output image signal (DS) (step S130).

[0151] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art or those with ordinary knowledge in the relevant technical field will understand that various modifications and changes can be made to the invention without departing from the spirit and technical scope of the invention as set forth in the claims below. Accordingly, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be determined by the claims. Explanation of the symbols

[0152] DD: Display device DP: Display Panel 100: Drive controller 110: Edge and tilt detector 120: Weight Calculator 130: 1st Gamma Corrector 140: Rendering section 150: Second gamma corrector 200: Data driving circuit 300: Scan driving circuit PX11-PXnm: Pixel PXA_R, PXA_G, PXA_B: First to third pixel regions

Claims

Claim 1 A display device comprising: a display panel; and a driving circuit that receives an input image signal and provides an output image signal corresponding to the input image signal to the display panel; wherein the driving circuit includes: an edge and slope detector that detects an edge of the input image signal and calculates an angle between the edge and a virtual line parallel to a first direction; a weight calculator that calculates a weight based on the edge and the angle; and a rendering unit that compensates the input image signal based on the weight and outputs the output image signal, wherein the weight is calculated by an arithmetic operation of the edge and the angle. Claim 2 In claim 1, the edge and slope detector calculates a first edge by convolution operation of the input image signal and a first filter, calculates a second edge by convolution operation of the input image signal and a second filter, and outputs the edge based on the first edge and the second edge. Claim 3 In Clause 2, the above edge is a mathematical formula A display device calculated by, wherein EG is the edge, EG_x is the first edge, and EG_y is the second edge. Claim 4 A display device according to claim 3, wherein the weight increases as the value of the edge increases, and the weight increases as the angle decreases. Claim 5 In Clause 2, the above edge is a mathematical formula A display device calculated by, wherein EG is the edge, EG_x is the first edge, and EG_y is the second edge. Claim 6 In claim 2, the first filter includes the determinant gx, and the second filter includes the determinant gy, and Display device. Claim 7 In claim 1, the weight calculator comprises a first lookup table storing a first compensation value corresponding to the edge; and a second lookup table storing a second compensation value corresponding to the angle. Claim 8 A display device according to claim 7, wherein the weight is calculated by the mathematical formula W=(LUT_EG×LUT_AG), where W is the weight, LUT_EG is the first compensation value, and LUT_AG is the second compensation value. Claim 9 In claim 7, the weight is calculated by the mathematical formula WQ=(LUT_EG×LUT_AG)×G_q, where WQ is the weight, LUT_EG is the first compensation value, LUT_AG is the second compensation value, and G_q is the panel compensation value, in a display device. Claim 10 In claim 1, the display panel is a display device comprising first to third pixels each disposed in first to third pixel regions. Claim 11 A display device according to claim 10, wherein the first pixel area is placed in a first pixel row, and the second pixel area and the third pixel area are placed in a second pixel row adjacent to the first pixel row. Claim 12 In claim 10, the input image signal comprises a display device including first to third color signals corresponding to each of the first to third pixels. Claim 13 A display device according to claim 12, wherein the rendering unit renders the first color signal using a first rendering filter including the weight, renders the second color signal using a second rendering filter including the weight, and renders the third color signal using a third rendering filter including the weight. Claim 14 A method of operation of a display device comprising: a step of detecting an edge of an input image signal; a step of calculating an angle between the edge and a virtual line parallel to a first direction; a weight calculator that calculates a weight based on the edge and the angle; and a rendering unit that compensates the input image signal based on the weight and outputs an output image signal, wherein the weight is calculated by an arithmetic operation of the edge and the angle. Claim 15 A method of operation of a display device according to claim 14, wherein the step of detecting the edge comprises calculating a first edge by convolution operation of the input image signal and a first filter, calculating a second edge by convolution operation of the input image signal and a second filter, and outputting the edge based on the first edge and the second edge. Claim 16 In claim 15, the above edge is a mathematical formula A method of operation of a display device calculated by, wherein EG is the edge, EG_x is the first edge, and EG_y is the second edge. Claim 17 A method of operation of a display device according to claim 16, wherein the weight increases as the angle becomes smaller, and the weight increases as the edge value becomes larger. Claim 18 In claim 15, the above edge is a mathematical formula A method of operation of a display device calculated by, wherein EG is the edge, EG_x is the first edge, and EG_y is the second edge. Claim 19 A method of operation of a display device according to claim 14, wherein the weight is calculated by the mathematical formula WQ=(LUT_EG×LUT_AG)×G_q, where WQ is the weight, LUT_EG is a first compensation value corresponding to the edge, LUT_AG is a second compensation value corresponding to the angle, and G_q is a panel compensation value. Claim 20 A method of operation of a display device according to claim 14, wherein the display panel of the display device comprises first to third pixels disposed in first to third pixel regions, wherein the first pixel region is disposed in a first pixel row, and the second pixel region and the third pixel region are disposed in a second pixel row adjacent to the first pixel row.

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