KR102604729B1 - Foldable display device and image quality compensation method - Google Patents

Abstract

A display device according to an embodiment of the present invention includes: a timing controller that receives image data and outputs a gate control signal and a data control signal; a data driver that receives the image data and the data control signal from the timing controller; a gate driver that receives the gate control signal from the timing controller; and a foldable display panel connected to the data driver through a data line, connected to the gate driver through a gate line, and outputting an image, wherein the timing controller includes a compensation control unit that compensates for input image data. The compensation control unit includes: a parameter receiving unit that receives in-folding/out-folding parameters and folding position parameters; a control area setting unit that sets a control area including a folding area and a non-folding area based on the parameters; and a compensation gain calculation unit that calculates compensation gains for the folding area and the non-folding area.

Description

Foldable display device and image quality improvement method {FOLDABLE DISPLAY DEVICE AND IMAGE QUALITY COMPENSATION METHOD}

The present invention relates to a foldable display device and a method for improving image quality thereof.

Display devices that display various information on a screen are a core technology of the information and communication era and are developing to be thinner, lighter, more portable, and more high-performance. Accordingly, organic light emitting display devices that display images by adjusting the amount of light emitted from organic light emitting diodes (OLEDs) are receiving attention.

In particular, foldable displays are also called flexible displays or bendable displays, and are beginning to be used in the latest devices, including foldable smartphones. Foldable displays can be manufactured with POLED (Plastic OLED), which can realize the flexibility of the display panel by replacing glass, which is an existing substrate material, with plastic.

When such a foldable display device is folded, a problem may occur in which the image quality of the image displayed on the folded portion is distorted.

Additionally, due to folding, the user's field of view changes from a frontal viewing angle to a side viewing angle, which may cause image quality distortion throughout the display device.

The purpose of the present invention is to provide a display device and a method for improving image quality that can improve image quality distortion that may occur when a foldable display device is folded.

A display device according to an embodiment of the present invention includes: a timing controller that receives image data and outputs a gate control signal and a data control signal; a data driver that receives the image data and the data control signal from the timing controller; a gate driver that receives the gate control signal from the timing controller; and a foldable display panel connected to the data driver through a data line, connected to the gate driver through a gate line, and outputting an image, wherein the timing controller includes a compensation control unit that compensates for input image data. The compensation control unit includes: a parameter receiving unit that receives in-folding/out-folding parameters and folding position parameters; a control area setting unit that sets a control area including a folding area and a non-folding area based on the parameters; and a compensation gain calculation unit that calculates compensation gains for the folding area and the non-folding area.

A method of improving image quality of a display device according to an embodiment of the present invention includes: receiving image data; Receiving in-folding/out-folding parameters and folding position parameters; setting a control area including a folding area and a non-folding area based on the parameters; calculating compensation gains for the folding area and the non-folding area; and applying the compensation gain to the image data.

According to the present invention, distortion of image quality that may occur due to the folding of a foldable display device can be improved.

According to the present invention, parameters necessary to improve image quality distortion that occurs when a foldable display device is folded can be optimized and defined.

According to the present invention, the area on the display panel that occurs when the foldable display device is folded can be optimized and defined.

According to the present invention, the power consumed in calculating image quality improvement can be minimized by optimizing and defining parameters and the area of the display panel.

1 is a block diagram of a display device according to an embodiment of the present invention.
2A and 2B are diagrams for explaining parameters according to the present invention.
Figure 3 is a diagram for explaining parameters according to the present invention.
Figure 4 is a diagram for explaining a control area according to the present invention.
Figure 5 is a diagram for explaining the calculation of compensation gain applied to the folding area according to the present invention.
Figure 6 is a diagram for explaining the calculation of compensation gain applied to the non-folding area according to the present invention.
Figure 7 is a diagram for explaining the compensation control unit according to the present invention.
Figure 8 is a flowchart for explaining the image quality improvement method according to the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. These embodiments only serve to ensure that the disclosure of the present invention is complete, and those skilled in the art It is provided to fully inform the person of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings.

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

Referring to FIG. 1, a display device according to an embodiment of the present invention includes a display panel (PANEL), a data driver (DD), a gate driver (GD), and a timing controller (TC).

The display panel (PANEL) includes a plurality of pixels (PXL) i horizontally and j vertically. The display panel (PANEL) is connected to the data driver (DD) through i data lines (DL1 to DLi). The display panel (PANEL) is connected to the gate driver (GD) through j gate lines (GL1 to GLj). That is, j pixels (PXL) arranged along one vertical line are commonly connected to one data line (DL1, DL2, etc.). Additionally, i pixels (PXL) arranged along one horizontal line are commonly connected to one gate line (GL1, GL2, etc.). The plurality of pixels (PXL) include a plurality of red pixels (R) for displaying a red image, a plurality of green pixels (G) for displaying a green image, and a plurality of blue pixels (B) for displaying a blue image. includes them. These plurality of pixels (PXL) are arranged in a matrix form on the display part of the display panel (PANEL). Each of the plurality of pixels (PXL) includes a thin film transistor (TFT) and a pixel electrode. The gate electrode of the thin film transistor is connected to the gate line to which the pixel is connected, the drain electrode of the thin film transistor is connected to the data line to which the pixel is connected, and the source electrode of the thin film transistor is connected to the pixel electrode.

The display panel (PANEL) is implemented as a liquid crystal display panel or an organic light emitting display panel depending on the configuration of the pixel circuit of the pixel (PXL). For example, when the display panel (PANEL) is implemented as a liquid crystal display panel, TN (Twisted Nematic) mode, VA (Vertical Alignment) mode, IPS (In Plane Switching) mode, FFS (Fringe Field Switching) mode, or ECB (Electrically It operates in Controlled Birefringence mode. For another example, when the display panel (PANEL) is implemented as an organic light emitting display panel, it operates in a top-emission method or a bottom-emission method. The display panel (PANEL) of the display device may be selected from a liquid crystal display panel, an organic light emitting display panel, an electrophoretic display panel, a plasma display panel, and a plastic organic light emitting display panel (POLED). However, it should be understood that the present invention is not limited to any one.

According to one embodiment, the pixels PXL may be formed in a stripe structure on the display panel PANEL. In this case, one pixel (PXL) may include a red subpixel, a green subpixel, and a blue subpixel, and may further include a white subpixel.

According to another embodiment, the pixels PXL may be formed in a pentile structure on the display panel PANEL. In this case, one pixel (PXL) may include one red subpixel, two green subpixels, and one blue subpixel arranged in a polygonal shape. For example, pixels (PXL) having a pentile structure may be arranged so that one red sub-pixel, two green pixels, and one blue sub-pixel have an octagonal shape. In this case, the blue sub-pixel is It has the largest size, and the green subpixel may have the smallest size.

The timing controller (TC) receives image data from the host system. The data driver (DD) and gate driver ( Controls the operation timing of GD). Additionally, the timing controller (TC) provides a gate control signal (GCS) to the gate driver (GD), and a data control signal (DCS) and image data (DATA) to the data driver (DD).

The data driver DD transmits i image data for displaying an image to i data lines DL1 to DLi. The data driver DD receives image data from the timing controller TC and transmits it to the data lines DL1 to DLi. That is, the data driver (DD) transmits red, green, and blue image data corresponding to i pixels of one horizontal line (GL1, GL2, etc.) driven by the gate driver (GD) to the data lines (DL1 to DLi). ) and transmit it to the display panel (PANEL). At this time, the data driver DD can sequentially output i image data divided into two times during one horizontal period (1H). That is, some of the i image data are output simultaneously during the first half of one horizontal period (1/2H) and simultaneously during the second half of one horizontal period (2/2H). Additionally, the data driver DD converts digital data into analog data based on the gamma voltage signal provided from the timing controller TC.

The gate driver (GD) sequentially drives j gate lines (GL1 to GLj) during one frame period and generates i pixels (PXL) commonly connected to the corresponding gate line for each horizontal period in which each gate line is driven. ) are driven. The gate driver (GD) sequentially supplies gate signals to each gate line (GL1 to GLi). In addition, the gate driver (GD) may supply a control signal having a voltage level determined for each of the initialization period, sampling period, offset voltage formation period, data writing period, and light emission period to each pixel (PXL). there is. These control signals may include an initialization signal, a sampling signal, a scan signal, and a light emission signal.

According to the present invention, the timing controller TC may include a compensation control unit 100.

The compensation control unit 100 may receive one or more parameters related to the display panel. One or more parameters include an in-folding/out-folding parameter indicating whether the folded display panel is in-folded or out-folded, a folding position parameter indicating the position at which folding is performed on the display panel, and a folding angle indicating the strength of the folding. parameter, and includes a viewing angle parameter that represents the angle between the display panel and the user.

Additionally, the compensation control unit 100 may set a control area on the display panel based on one or more parameters. The control area may include a folding area and a non-folding area. The non-folding area may include a first non-folding area and a second non-folding area based on the folding position. Each of the first non-folding area and the second non-folding area may include a near area and a far area.

Additionally, the compensation control unit 100 may calculate a compensation gain to be applied to the set control area. The compensation gain is a gain to improve the image quality of the foldable display panel, and may include chrominance, luminance, and color temperature of the output image.

A detailed description of the compensation control unit 100 will be described later.

The compensation control unit 100 may be exemplarily included in the timing controller TC, and should be understood as exemplary. That is, the compensation control unit 100 may exist independently in a stage before the timing controller TC, may exist independently in a stage after the timing controller TC, and may be included in other components.

2A and 2B are diagrams for explaining parameters according to the present invention.

Referring to FIGS. 2A and 2B, a folded display panel appears, with FIG. 2A showing an in-folded foldable display panel and FIG. 2B showing an out-folded foldable display panel. Specifically, when the center of the display panel moves away from the user and the sides of the display panel move closer to the user due to folding, it is referred to as in-folding (FIG. 2a). Additionally, when the center of the display panel becomes closer to the user and the sides of the display panel move away from the user due to folding, it is referred to as out-folding (FIG. 2b).

The in-folding/out-folding parameter is a parameter that indicates whether the folded display panel is in-folding or out-folding. These in-folding/out-folding parameters may be received from an AP (application processor) or CPU (central processor unit) of a device (eg, TV or smartphone) including a display device.

Additionally, referring to FIGS. 2A and 2B, the folding position appears. The folding position refers to the position where folding occurred on the display panel. For example, when the entire area of the display panel is displayed as x-coordinates and y-coordinates, in the example referring to FIGS. 2A and 2B, the folding position may be one position on the x-coordinate. In another embodiment (for example, when the display panel is folded from top to bottom), the folding position may be a single position on the y coordinate. Alternatively, when the positions of a plurality of pixels built into the display panel are determined in advance, the folding positions may be determined in correspondence with the positions of the pixels. For example, the location of a plurality of pixels where folding has occurred may be referred to as a folding location. These in-folding/out-folding parameters may be received from an AP (application processor) or CPU (central processor unit) of a device (eg, TV or smartphone) including a display device.

Additionally, referring to Figures 2A and 2B, the folding angle appears. The folding angle is a parameter that defines the degree to which the display panel is folded. For example, the folding angle can be defined as the angle formed by two parts of the display panel divided around the folding position. In this case, the larger the folding angle (closer to 180 degrees), the smaller the degree of folding, and the smaller the folding angle (closer to 0 degrees), the greater the degree of folding. This definition of the folding angle is an example and may be used in other ways to distinguish the degree of the display panel. For example, another method may be used in which the larger the folding angle, the greater the degree of folding, and the smaller the folding angle, the smaller the degree of folding. These in-folding/out-folding parameters may be received from an AP (application processor) or CPU (central processor unit) of a device (eg, TV or smartphone) including a display device.

Figure 3 is a diagram for explaining parameters according to the present invention.

Referring to FIG. 3, the folded display panel is divided into two planes (plane A and plane B) centered on the folding position.

The viewing angle parameter refers to the angle between the plane of the folded display panel and the user's field of view. For example, in the example of FIG. 3, it means the angle formed between plane A or plane B and the user's field of view. For example, the angle between plane A and the user's field of view may be 30 degrees, and the angle between plane B and the user's field of view may be 65 degrees. In other words, the larger the viewing angle (closer to 90 degrees), the more directly the user is looking at the corresponding plane. The smaller the viewing angle (closer to 0 degrees), the more the user is looking to the side of that plane. This definition of the viewing angle is illustrative and may be used in other ways to distinguish the degree to which the user is looking directly at the panel. For example, a different method may be used in which the larger the viewing angle is, the more you look to the side, and the smaller the viewing angle is, the more you are looking straight ahead. These viewing angle parameters can be obtained from a sensor mounted on a device including a display device (eg, a TV or smartphone). For example, sensors may include gyroscope sensors and camera sensors. A gyroscope sensor is a sensor that displays the angle that a device including a display device makes with respect to the ground, and can provide data to obtain viewing angle parameters. The camera sensor is attached to the front or side of the device and can capture the user's face or pupil to sense the user's position and opposing angle, which can be used as data to obtain viewing angle parameters.

Figure 4 is a diagram for explaining a control area according to the present invention.

According to the present invention, a folded display panel includes a folding area and a non-folding area, and the non-folding area includes a first non-folding area and a second non-folding area.

The folding area is an area including a folding position, and the folding area can be set based on the folding position parameter and the folding angle parameter. Specifically, an area extended by a preset distance (D) centered on the folding position can be set as the folding area. The preset distance (D) can be varied based on the folding angle parameter. For example, if the folding angle is large (if the degree of folding is small), the preset distance (D) may be relatively small, and if the folding angle is small (if the degree of folding is large), the preset distance (D) may be relatively small. can be relatively large. That is, if the folding angle is large (if the degree of folding is small), the folding area can be set relatively narrow, and if the folding angle is small (if the degree of folding is large), the folding area can be set relatively wide. It can be.

The non-folding area is the remaining area excluding the folding area among the entire panel area. The non-folding region is divided into two regions based on the folding region (or folding position), one of which will be referred to as the first non-folding region, and the other will be referred to as the second non-folding region.

Figure 5 is a diagram for explaining the calculation of compensation gain applied to the folding area according to the present invention.

In the case of in-folding, the output image may be distorted in the folding area. For example, referring to the left side of FIG. 5, distortion that increases luminance may occur in the folding area. That is, even when the same gray level value is input for all areas of the display panel, distortion may occur in which the luminance of the output image in the folding area is output brighter than the surrounding area (non-folding area). This distortion phenomenon may occur because the density of pixels relative to unit area increases due to in-folding. However, this distortion is an example, and depending on the type of display panel, etc., distortion may occur in which the luminance is lower than that of the surrounding area, and all such embodiments should be understood as being included in the technical idea of the present invention. In this embodiment, luminance is used as an example, but other types of image quality distortion (eg, color, color temperature, etc.) may occur in the folding area due to in-folding.

Accordingly, according to the present invention, in the case of in-folding, the compensation gain applied to the folding area may be a gain that reduces image quality distortion. For example, when distortion that increases the luminance of the folding area occurs due to in-folding, a compensation gain (a value less than 1) that reduces the input grayscale of the input image data may be calculated. For another example, when distortion that lowers the luminance of the folding area occurs due to in-folding, a compensation gain (a value greater than 1) that increases the input grayscale of the input image data may be calculated.

Additionally, the compensation gain applied to the folding area may be calculated based on the folding angle. For example, if the folding angle obtained by the folding angle parameter is small (if the degree of folding is large), a gain that generates a relatively large amount of change can be calculated, and if the folding angle is large (if the degree of folding is small) A gain that generates a relatively small amount of change can be calculated.

In the case of outfolding, distortion may occur in the output image in the folding area. For example, referring to the right side of FIG. 5, distortion that lowers luminance may occur in the folding area. That is, even when the same gray level value is input for all areas of the display panel, distortion may occur in which the luminance of the output image in the folding area is darker than the surrounding area (non-folding area). This distortion phenomenon may occur due to a decrease in pixel density compared to unit area due to outfolding. However, this distortion is an example, and depending on the type of display panel, etc., a distortion that increases luminance compared to the surrounding area may occur, and all such embodiments should be understood as being included in the technical spirit of the present invention. In this embodiment, luminance is used as an example, but other types of image quality distortion (eg, color, color temperature, etc.) may occur in the folding area due to outfolding.

Accordingly, according to the present invention, in the case of outfolding, the compensation gain applied to the folding area may be a gain that reduces image quality distortion. For example, when distortion occurs that lowers the luminance of the folded area due to outfolding, a compensation gain (a value higher than 1) that increases the input grayscale of the input image data may be calculated. For another example, when distortion that increases luminance occurs due to outfolding, a compensation gain (a value less than 1) that reduces the input gray level of the input image data may be calculated.

Additionally, the compensation gain applied to the folding area may be calculated based on the folding angle. For example, if the folding angle obtained by the folding angle parameter is small (if the degree of folding is large), a gain that generates a relatively large amount of change can be calculated, and if the folding angle is large (if the degree of folding is small) A gain that generates a relatively small amount of change can be calculated.

Figure 6 is a diagram for explaining the calculation of compensation gain applied to the non-folding area according to the present invention.

The non-folding area is defined as the remaining area excluding the folding area among the entire panel area, and the folding area is the area containing the folding position. The non-folding region includes a first non-folding region and a second non-folding region centered on the folding region.

The viewing angle parameter refers to the angle formed by the user's field of view for each of the first non-folding area and the second non-folding area. The description will be made by taking as an example that the viewing angle parameter for the first non-folding area is 30 degrees, and the viewing angle parameter for the second non-folding area is 65 degrees.

The two folding regions formed due to folding (including both in-folding and out-folding) produce a viewing angle due to the folding. In other words, as the viewing angle increases, the user looks at the tilted screen instead of looking straight at the non-folding area, which causes distortion of image quality. Referring to FIG. 6, the viewing angle of the first non-folding area is 30 degrees, thereby lowering the luminance of the screen visually perceived by the user. In other words, compared to the output image, the actual image perceived by the user becomes a dark image. Likewise, the second non-folding area has a viewing angle of 65 degrees, so the luminance of the screen visually displayed by the user is lowered. This distortion is an example, and depending on the type of display panel, etc., the user may perceive the screen as having higher brightness. Additionally, although this embodiment uses luminance as an example, other types of image quality distortion (eg, color, color temperature, etc.) may occur in the non-folding area due to folding.

Therefore, according to the present invention, the compensation gain applied to the non-folding area may be a gain that reduces image quality distortion. For example, when the luminance of the image perceived by the user decreases due to the viewing angle, a compensation gain (a value greater than 1) that increases the input grayscale of the input image data may be calculated. For another example, when the luminance of the image perceived by the user increases due to the viewing angle, a compensation gain (a value less than 1) that reduces the input gray level of the input image data may be calculated.

Figure 7 is a diagram for explaining the compensation control unit according to the present invention.

Referring to FIG. 7, the compensation control unit 100 according to the present invention includes a parameter reception unit 110, a control area setting unit 120, and a compensation gain calculation unit 130.

The parameter receiver 110 may receive in-folding/out-folding parameters, folding position parameters, folding angle parameters, and viewing angle parameters.

The in-folding/out-folding parameter is a parameter that indicates whether the folded display panel is in-folding or out-folding, and can be received from the AP or CPU of the device including the display device. The folding position parameter is a parameter indicating the position where the folding occurred on the display panel, and can be received from the AP or CPU of the device including the display device. The folding angle parameter is a parameter that defines the degree to which the display panel is folded, and can be received from the AP or CPU of the device including the display device. The viewing angle parameter is a parameter for defining the angle between a portion of the plane of the folded display panel (e.g., first non-folding area, second non-folding area) and the user's field of view, and is a sensor mounted on a device including a display device. It can be obtained from. Sensors may include, for example, a gyroscope, a camera sensor.

The control area setting unit 120 may set a control area including a folding area and a non-folding area based on the folding position parameter. Specifically, the folding area may be an area containing a folding position. The non-folding area may be the remaining area of the entire area of the display panel excluding the folding area, and may be divided into a first non-folding area and a second non-folding area centered on the folding position. Additionally, the control area setting unit 120 may set an area spaced apart from the folding position by a preset distance as the folding area. The preset distance for setting the folding area may be variable depending on the folding angle. For example, when the folding angle is large (if the degree of folding is small), the preset distance may be relatively small, and when the folding angle is small (if the degree of folding is large), the preset distance may be relatively large.

The compensation gain calculator 130 may calculate a gain applied to the in-folding area and calculate a gain applied to the out-folding area based on the in-folding/out-folding parameters. Based on the type and nature of the display panel, the in-folding area application gain and the out-folding area application gain may be different from each other. For example, image quality distortion occurring in the folding area of in-folding may be opposite to image quality distortion occurring in the folding area of out-folding. For example, if the luminance increases in the folding area due to in-folding, the luminance may decrease in the folding area due to out-folding. The compensation gain calculation unit may calculate a gain to reduce image quality distortion that occurs. For example, when distortion that increases luminance occurs in the folding area of in-folding, the compensation gain may be set to a gain smaller than 1 to reduce the input grayscale of the input image data. For example, when distortion that reduces luminance occurs in the folding area of outfolding, the compensation gain may be set to a gain greater than 1 to increase the input grayscale of the input image data.

Additionally, the compensation gain calculator 130 may calculate a gain applied to the folding area of in-folding and the folding area of out-folding based on the folding angle parameter. For example, when the folding angle is small and the degree of folding is large, a gain that generates a relatively large amount of change can be calculated, and when the folding angle is large and the degree of folding is small, a gain that generates a relatively small amount of change can be calculated. The gain can be calculated.

The compensation gain calculator 130 may calculate a gain applied to the non-folding area based on the field of view parameter. According to the present invention, the viewing angle of a user facing the display panel can change to a side viewing angle due to folding (including both in-folding and out-folding). As a side viewing angle occurs, distortion of image quality including luminance, color difference, and color temperature occurs in the output image perceived by the user. The compensation gain calculator 130 may calculate a gain to reduce distortion based on the viewing angle parameter. For example, as the non-folding area and viewing angle become larger, a gain that generates a relatively large amount of change can be calculated, and as the viewing angle becomes smaller, a gain that generates a relatively small amount of change can be calculated.

Figure 8 is a flowchart for explaining the image quality improvement method according to the present invention.

A step (S110) of receiving image data is performed. Image data may include values that determine the image quality of the image. For example, it may include values that determine image quality, including luminance, color difference, and color temperature of the output image.

A step of receiving parameters (S120) is performed. Parameters include in-folding/out-folding parameters, folding position parameters, folding angle parameters, and viewing angle parameters. The in-folding/out-folding parameter is a parameter that indicates whether the folded display panel is in-folding or out-folding, and can be received from the AP or CPU of the device including the display device. The folding position parameter is a parameter indicating the position where the folding occurred on the display panel, and can be received from the AP or CPU of the device including the display device. The folding angle parameter is a parameter that defines the degree to which the display panel is folded, and can be received from the AP or CPU of the device including the display device. The viewing angle parameter is a parameter for defining the angle between a portion of the plane of the folded display panel (e.g., first non-folding area, second non-folding area) and the user's field of view, and is a sensor mounted on a device including a display device. It can be obtained from. Sensors may include, for example, a gyroscope, a camera sensor.

A step (S130) of setting a control area is performed. The control area includes a folding area set based on the folding position parameter, and a non-folding area that is an area excluding the folding area. The non-folding area may include a first non-folding area and a second non-folding area based on the folding position. An area spaced apart by a preset distance from the folding position may be set as the folding area. Additionally, the preset distance may be variable depending on the folding angle. For example, when the folding angle is large (if the degree of folding is small), the preset distance may be relatively small, and when the folding angle is small (if the degree of folding is large), the preset distance may be relatively large.

A step (S140) of calculating a compensation gain is performed. Specifically, the gain applied to the in-folding area can be calculated based on the in-folding/out-folding parameters, and the gain applied to the out-folding area can be calculated. Based on the type and nature of the display panel, the in-folding area application gain and the out-folding area application gain may be different from each other. For example, image quality distortion occurring in the folding area of in-folding may be opposite to image quality distortion occurring in the folding area of out-folding. For example, if the luminance increases in the folding area due to in-folding, the luminance may decrease in the folding area due to out-folding. The calculated compensation gain may be a gain to reduce image quality distortion that occurs. For example, when distortion that increases luminance occurs in the folding area of in-folding, the compensation gain may be less than 1 to reduce the input grayscale of the input image data. For another example, when distortion that reduces luminance occurs in the folding area of outfolding, the compensation gain may be set to a gain greater than 1 to increase the input grayscale of the input image data.

Additionally, the gain applied to the folding area of in-folding and the folding area of out-folding may be calculated based on the folding angle parameter. For example, when the folding angle is small and the degree of folding is large, a gain that generates a relatively large amount of change can be calculated, and when the folding angle is large and the degree of folding is small, a gain that generates a relatively small amount of change can be calculated. The gain can be calculated. Additionally, the gain applied to the non-folding area can be calculated based on the field of view parameter.

A step (S150) of applying a compensation gain is performed. For example, if the compensation gain is less than 1, the input gray level of the input image data will be reduced. For another example, if the compensation gain is greater than 1, the input gray level of the input image data will increase.

According to the present invention, the viewing angle of a user facing the display panel can change to a side viewing angle due to folding (including both in-folding and out-folding). As a side viewing angle occurs, distortion of image quality, including luminance, color difference, and color temperature, occurs in the output image perceived by the user. The calculated compensation gain may be a gain to reduce distortion that occurs based on the viewing angle parameter. For example, as the viewing angle with the non-folding area is larger, a gain that generates a relatively large amount of change can be calculated, and as the viewing angle is small, a gain that generates a relatively small amount of change can be calculated.

Although the description has been made with reference to the above embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will be able to. In addition, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, and all technical ideas within the scope of the following patent claims and equivalents should be construed as being included in the scope of the present invention. .

TC: Timing Controller DD: Data Driver
GD: Gate driver PANEL: Display panel
PXL: Pixel 100: Compensation Control

Claims (14)

A timing controller that receives video data and outputs a gate control signal and a data control signal;
a data driver that receives the image data and the data control signal from the timing controller;
a gate driver that receives the gate control signal from the timing controller; and
A foldable display panel connected to the data driver through a data line, connected to the gate driver through a gate line, and outputting an image,
The timing controller includes a compensation control unit that compensates for input image data, and the compensation control unit:
A parameter receiving unit that receives in-folding/out-folding parameters and folding position parameters;
a control area setting unit that sets a control area including a folding area and a non-folding area based on the folding position parameter;
Comprising a compensation gain calculation unit that calculates compensation gains for the folding area and the non-folding area,
The compensation gain calculation unit,
The luminance of the folding area is controlled differently depending on whether the folding area is in-folded/out-folded based on a change in pixel density of the folding area, and if the folding direction determined based on the in-folding/out-folding parameters is in-folding, the folding area Controlling the brightness of the non-folding area to be lower than that of the non-folding area, and controlling the brightness of the folding area to be higher than that of the non-folding area if the folding direction is out-folding.
display device. According to claim 1,
The control area setting unit sets the area including the folding position as the folding area and sets the area excluding the folding area as the non-folding area,
display device. According to claim 2,
The control area setting unit sets an area spaced apart from the folding position by a preset distance as the folding area,
display device. According to claim 3,
The parameter receiver additionally receives a folding angle parameter,
The preset distance varies depending on the folding angle parameter,
Display device. According to claim 1,
The compensation gain calculation unit calculates a gain applied to the folding area of in-folding or the folding area of out-folding based on the in-folding/out-folding parameters.
Display device. According to claim 5,
The parameter receiver additionally receives a folding angle parameter,
The compensation gain calculation unit calculates a gain applied to the folding area of the in-folding or the folding area of the out-folding based on the folding angle parameter.
display device. According to claim 1,
The parameter receiver additionally receives a viewing angle parameter,
The compensation gain calculation unit calculates a gain applied to the non-folding area based on the viewing angle parameter,
Display device. Receiving video data;
Receiving in-folding/out-folding parameters and folding position parameters;
setting a control area including a folding area and a non-folding area based on the folding position parameter;
calculating compensation gains for the folding area and the non-folding area; and
Including applying the compensation gain to the image data,
The step of calculating the compensation gain is,
If the folding direction determined based on the in-folding/out-folding parameters is in-folding, the compensation gain is determined to control the luminance of the folding area to be lower than that of the non-folding area, and if the folding direction is out-folding, the compensation gain is determined to control the brightness of the folding area to be lower than that of the non-folding area. Determining the compensation gain to control luminance to be higher than the non-folding area,
The luminance is controlled differently depending on in-folding/out-folding based on the change in pixel density of the folding area.
How to improve the picture quality of a display device. According to claim 8,
Setting the control area includes setting an area including the folding position as the folding area and setting an area excluding the folding area as the non-folding area.
How to improve the picture quality of a display device. According to clause 9,
Setting the control area includes setting an area spaced apart from the folding position by a preset distance as the folding area,
How to improve the picture quality of a display device. According to claim 10,
further comprising receiving a folding angle parameter,
The preset distance varies depending on the folding angle parameter,
How to improve the picture quality of a display device. According to claim 8,
The step of calculating the compensation gain includes calculating a gain applied to the folding area of in-folding or the folding area of out-folding based on the in-folding/out-folding parameters.
How to improve the picture quality of a display device. According to claim 12,
further comprising receiving a folding angle parameter,
The step of calculating the compensation gain includes calculating a gain applied to the folding area of the in-folding or the folding area of the out-folding based on the folding angle parameter.
How to improve the picture quality of a display device. According to claim 8,
further comprising receiving a viewing angle parameter,
Calculating the compensation gain includes calculating a gain applied to the non-folding area based on the viewing angle parameter,
How to improve the picture quality of a display device.

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