Display device supporting a partial driving mode, and method of operating a display device

A foldable display device includes a display panel with a first display region, a second display region and a foldable display region located between the first and seconds display regions. A degradation information storage stores first degradation information for a first edge region and second degradation information for a second edge region. An edge information extractor extracts, in a first partial driving mode, first edge information for the first edge region from first partial image data, and extracts, in a second partial driving mode, second edge information for the second edge region from second partial image data. A gradation image generator generates, in the first partial driving mode, first gradation data based on the first edge information and the second degradation information, and generates, in the second partial driving mode, second gradation data based on the first degradation information and the second edge information.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority under 35 USC § 119 from, and the benefit of, Korean Patent Application No. 10-2019-0162823, filed on Dec. 9, 2019 in the Korean Intellectual Property Office (KIPO), the contents of which are herein incorporated by reference in their entirety.

BACKGROUND

1. Technical Field

Exemplary embodiments are directed to a display device, and more particularly to a display device that supports a partial driving mode, and a method of operating the display device.

2. Discussion of the Related Art

Flexible display devices, such as a foldable display device that has at least a partially deformable display panel, have been recently developed. This flexible display device can be deformed such that a partial region of a display panel is viewable by a user, but the remaining region of the display panel is not viewable by the user In this case, to reduce power consumption, a flexible display device can operate in a partial driving mode which drives only the partial region of the display panel that is viewed by the user. However, in a flexible display device that supports a partial driving mode, display regions driven in the partial driving mode and not driven in the partial driving mode can have a degradation deviation, in which an image sticking phenomenon occurs between the driven display region and the non-driven display region.

SUMMARY

Some exemplary embodiments provide a display device that prevents or reduces an image sticking caused by a degradation deviation.

Some exemplary embodiments provide a method of operating a display device that prevents or reduces an image sticking caused by a degradation deviation.

According to exemplary embodiments, there is provided a display device that includes a display panel that includes a first display region, a second display region, and an intermediate display region located between the first display region and the second display region, a degradation information storage that stores first degradation information for a first edge region within the first display region that is adjacent to the intermediate display region, and second degradation information for a second edge region within the second display region that is adjacent to the intermediate display region, an edge information extractor that extracts, in a first partial driving mode in which the first display region is driven, first edge information for the first edge region from first partial image data for the first display region, and that extracts, in a second partial driving mode in which the second display region is driven, second edge information for the second edge region from second partial image data for the second display region, and a gradation image generator that generates, in the first partial driving mode, first gradation data for the intermediate display region based on the first edge information and the second degradation information, and that generates, in the second partial driving mode, second gradation data for the intermediate display region based on the first degradation information and the second edge information.

In exemplary embodiments, the display panel is an out-foldable display panel, and the intermediate display region is a foldable region of the out-foldable display panel.

In exemplary embodiments, the display device operates in the first partial driving mode when the out-foldable display panel is folded such that the first display region is located at a front side and the second display region is located at a back side, and the display device operates in the second partial driving mode when the out-foldable display panel is folded such that the second display region is located at the front side and the first display region is located at the back side.

In exemplary embodiments, the gradation image generator generates the first gradation data such that the first gradation data continuously change from a gray value represented by the first edge information to a gray value represented by the second degradation information along a first direction from the first display region to the second display region. The gradation image generator generates the second gradation data such that the second gradation data continuously change from a gray value represented by the first degradation information to a gray value represented by the second edge information along the first direction.

In exemplary embodiments, the gradation image generator calculates a first edge block gray value by calculating an average of N consecutive gray values represented by the first edge information, where N is an integer greater than 1, calculates a second degradation block gray value by calculating an average of N consecutive gray values represented by the second degradation information, and generates the first gradation data such that the first gradation data continuously change from the first edge block gray value to the second degradation block gray value along a first direction from the first display region to the second display region. The gradation image generator calculates a first degradation block gray value by calculating an average of N consecutive gray values represented by the first degradation information, calculates a second edge block gray value by calculating an average of N consecutive gray values represented by the second edge information, and generates the second gradation data such that the second gradation data continuously change from the first degradation block gray value to the second edge block gray value along the first direction.

In exemplary embodiments, the gradation image generator calculates a first edge weighted moving average by calculating a weighted moving average of N consecutive gray values represented by the first edge information, where N is an integer greater than 1, calculates a second degradation weighted moving average by calculating a weighted moving average of N consecutive gray values represented by the second degradation information, and generates the first gradation data such that the first gradation data continuously change from the first edge weighted moving average to the second degradation weighted moving average along a first direction from the first display region to the second display region. The gradation image generator calculates a first degradation weighted moving average by calculating a weighted moving average of N consecutive gray values represented by the first degradation information, calculates a second edge weighted moving average by calculating a weighted moving average of N consecutive gray values represented by the second edge information, and generates the second gradation data such that the second gradation data continuously change from the first degradation weighted moving average to the second edge weighted moving average along the first direction.

In exemplary embodiments, the first edge region includes first M pixel lines, where M is an integer greater than 0, and the second edge region includes second M pixel lines. The edge information extractor generates the first edge information by calculating an average of M gray levels represented by the first partial image data for the first M pixel lines, and generates the second edge information by calculating an average of M gray levels represented by the second partial image data for the second M pixel lines.

In exemplary embodiments, the first edge region includes first M pixel lines, where M is an integer greater than 0, and the second edge region includes second M pixel lines. The edge information extractor generates the first edge information by extracting a maximum of M gray levels represented by the first partial image data for the first M pixel lines, and generates the second edge information by extracting a maximum of M gray levels represented by the second partial image data for the second M pixel lines.

In exemplary embodiments, the first edge region includes first M pixel lines, w here M is an integer greater than 0, and the second edge region includes second M pixel lines. The edge information extractor generates the first edge information by calculating a weighted average of M gray levels represented by the first partial image data for the first M pixel lines with a weight that decreases as a distance from the intermediate display region increases, and generates the second edge information by calculating a weighted average of M gray levels represented by the second partial image data for the second M pixel lines with a weight that decreases as a distance from the intermediate display region increases.

In exemplary embodiments, the first degradation information is updated every L frames by calculating an average of accumulated gray values represented by the first degradation information and current gray values represented by current image data for the first edge region, where L is an integer greater than 0, and the second degradation information is updated every L frames by calculating an average of accumulated gray values represented by the second degradation information and current gray values represented by current image data for the second edge region.

In exemplary embodiments, each of the first degradation information and the second degradation information includes K accumulated gray values, where K is an integer greater than 0, and one of the K accumulated gray values of each of the first degradation information and the second degradation information is updated every L frames, where L is an integer greater than 0.

In exemplary embodiments, each pixel of the display panel includes a red sub-pixel, a green sub-pixel and a blue sub-pixel. The gradation image generator generate, in the first partial driving mode, the first gradation data with respect to each of the red sub-pixel, the green sub-pixel and the blue sub-pixel, and generates, in the second partial driving mode, the second gradation data with respect to each of the red sub-pixel, the green sub-pixel and the blue sub-pixel.

In exemplary embodiments, each pixel of the display panel includes a red sub-pixel, a green sub-pixel and a blue sub-pixel. The gradation image generator generates, in the first partial driving mode, the first gradation data that represents a first same gray value with respect to each of the red sub-pixel, the green sub-pixel and the blue sub-pixel in a same pixel, and generates, in the second partial driving mode, the second gradation data that represents a second same gray value with respect to each of the red sub-pixel, the green sub-pixel and the blue sub-pixel in the same pixel.

In exemplary embodiments, the display device further includes a scan driver that includes first stages that sequentially transmit first scan signals to the first display region in response to a first scan start signal, second stages that sequentially transmit second scan signals to the intermediate display region in response to a second scan start signal, and third stages that sequentially transmit third scan signals to the second display region in response to a third scan start signal.

In exemplary embodiments, the display device further includes a data driver that transmits data signals to the display panel. In the first partial driving mode, the data driver transmits the data signals that correspond to the first partial image data to the first display region and the data signals that correspond to the first gradation data to the intermediate display region such that an image that corresponds to the first partial image data is displayed in the first display region and a first gradation image that corresponds to the first gradation data is displayed in the intermediate display region. In the second partial driving mode, the data driver transmits the data signals that correspond to the second partial image data to the second display region and the data signals that correspond to the second gradation data to the intermediate display region such that an image that corresponds to the second partial image data is displayed in the second display region and a second gradation image that corresponds to the second gradation data is displayed in the intermediate display region.

In exemplary embodiments, in a third partial driving mode in which the first display region and the second display region are driven, the gradation image generator generates third gradation data for the intermediate display region based on the first edge information and the second edge information.

According to exemplary embodiments, there is provided a method of operating a display device that includes a display panel that includes a first display region, a second display region, and an intermediate display region located between the first display region and the second display region. The method includes storing first degradation information for a first edge region within the first display region that is adjacent to the intermediate display region, storing second degradation information for a second edge region within the second display region that is adjacent to the intermediate display region, extracting first edge information for the first edge region from first partial image data for the first display region in a first partial driving mode in which the first display region is driven, extracting second edge information for the second edge region from second partial image data for the second display region in a second partial driving mode in which the second display region is driven, generating, in the first partial driving mode, first gradation data for the intermediate display region based on the first edge information and the second degradation information, generating, in the second partial driving mode, driving, second gradation data for the intermediate display region based on the first degradation information and the second edge information, driving, in the first partial driving mode, the first display region and the intermediate display region based on the first partial image data and the first gradation data, and driving, in the second partial driving mode, the second display region and the intermediate display region based on the second partial image data and the second gradation data.

In exemplary embodiments, the first gradation data is generated such that the first gradation data continuously change from a gray value represented by the first edge information to a gray value represented by the second degradation information along a first direction from the first display region to the second display region, and the second gradation data is generated such that the second gradation data continuously change from a gray value represented by the first degradation information to a gray value represented by the second edge information along the first direction.

In exemplary embodiments, a first edge block gray value is calculated by calculating an average of N consecutive gray values represented by the first edge information, where N is an integer greater than 1, a second degradation block gray value is calculated by calculating an average of N consecutive gray values represented by the second degradation information, and the first gradation data is generated such that the first gradation data continuously change from the first edge block gray value to the second degradation block gray value along a first direction from the first display region to the second display region. A first degradation block gray value is calculated by calculating an average of N consecutive gray values represented by the first degradation information, a second edge block gray value is calculated by calculating an average of N consecutive gray values represented by the second edge information, and the second gradation data is generated such that the second gradation data continuously change from the first degradation block gray value to the second edge block gray value along the first direction.

In exemplary embodiments, a first edge weighted moving average is calculated by calculating a weighted moving average of N consecutive gray values represented by the first edge information, where N is an integer greater than 1, a second degradation weighted moving average is calculated by calculating a weighted moving average of N consecutive gray values represented by the second degradation information, and the first gradation data is generated such that the first gradation data continuously change from the first edge weighted moving average to the second degradation weighted moving average along a first direction from the first display region to the second display region. A first degradation weighted moving average is calculated by calculating a weighted moving average of N consecutive gray values represented by the first degradation information, a second edge weighted moving average is calculated by calculating a weighted moving average of N consecutive gray values represented by the second edge information, and the second gradation data is generated such that the second gradation data continuously change from the first degradation weighted moving average to the second edge weighted moving average along the first direction.

As described above, in a display device and a method of operating the display device according to exemplary embodiments, first degradation information for a first edge region of a first display region and second degradation information for a second edge region of a second display region are stored, first gradation data for an intermediate display region is generated in a first partial driving mode based on first edge information for the first edge region and the second degradation information for the second edge region, and second gradation data for the intermediate display region is generated in a second partial driving mode based on the first degradation information for the first edge region and second edge information for the second edge region. Accordingly, image sticking is not perceived between the first edge region and the intermediate display region, and between the intermediate display region and the second edge region.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, exemplary embodiments of the present inventive concept will be explained in detail with reference to the accompanying drawings.

FIG. 1is a block diagram of a display device according to exemplary embodiments,FIG. 2illustrates an example of an out-foldable display device according to exemplary embodiments.FIG. 3Aillustrates an operation of a display device in a first partial driving mode according to exemplary embodiments,FIG. 3Billustrates an operation of a display device in a second partial driving mode according to exemplary embodiments,FIG. 3Cillustrates an operation of a display device in a third partial driving mode according to exemplary embodiments,FIG. 4illustrates an example of a foldable display device having two or more foldable regions,FIG. 5is a block diagram of an example of a scan driver included in a display device according to exemplary embodiments,FIG. 6Aillustrates an example of first gradation data generated in a first partial driving mode,FIG. 6Billustrates an example of second gradation data generated in a second partial driving mode, andFIG. 7illustrates luminance of a display device that does not generate gradation data and luminance at a display device that generates gradation data according to exemplary embodiments.

Referring toFIG. 1, a display device100according to exemplary embodiments include a display panel110that includes a plurality of pixels, a scan driver120that provides scan signals SS1, SS2and SS3to the plurality of pixels, a data driver130that provides data signals DS to the plurality of pixels, and a controller140that controls the scan driver120and the data driver130.

According to embodiments, the display panel110includes a plurality of data lines, a plurality of scan lines, and the plurality of pixels are coupled to the plurality of data lines and the plurality of scan lines. In some exemplary embodiments, each pixel includes at least one capacitor, at least two transistors and an organic light emitting diode (OLED), and the display panel110is an OLED display panel. In other exemplary embodiments, the display panel110is a liquid crystal display (LCD) panel, or any other suitable display panel.

According to embodiments, as illustrated inFIG. 1, the display panel110includes a first display region111, a second display region112, and an intermediate or boundary display region113between the first display region111and the second display region112. The first display region111, rite intermediate display region113and the second display region112are continuously formed. In some exemplary embodiments, as illustrated inFIG. 2, the display panel110is an out-foldable display panel110aof an out-foldable display device100a, and the intermediate display region113is a foldable region113aof the out-foldable display panel110ain which the out-foldable display panel110ais folded. Further, for example, the first and second display regions111and112may be, but are not limited to, first and second flat display regions111aand112aof the out-foldable display panel110a.

In some exemplary embodiments, as illustrated inFIG. 3A, when the out-foldable display panel110ais folded such that the first (flat) display region111ais located at a front side and the second (flat) display region112ais located at a back side, the out-foldable display device100aoperates in a first partial driving mode in which the first display region111ais driven and the second display region112ais not driven. Here, the front side is a top side, or a side that is viewable by a user180. Further, the back side may be a bottom side, or a side that is not viewed by the user180. The second display region112alocated at the back side which is not viewable by the user180is not driven, and thus power consumption of the out-foldable display panel110ais reduced. Further, as illustrated inFIG. 3B, when the out-foldable display panel110ais folded such that the second display region112ais located at the front side and the first display region111ais located at the back side, the out-foldable display device100aoperates in a second partial driving mode in which the first display region111ais not driven and the second display region112ais driven.

In some exemplary embodiments, in addition to the first and second partial driving modes, a partial driving mode of the out-foldable display device100afurther includes a third partial driving mode in which the first and second display regions111aand112aare driven to display different images. For example, as illustrated inFIG. 3C, an image in the first display region111ais displayed to a first user182, and an image in the second display region112ais displayed to a second user184.

In other exemplary embodiments, as illustrated inFIG. 4, the display panel110is a foldable display panel110bof a foldable display device100bthat includes two or more foldable regions113band115b. The foldable display device100bincludes first, second and third (flat) display regions111b,112band114band first and second intermediate display regions113band115b, or first and second foldable regions113band115b. AlthoughFIGS. 2 through 4illustrate examples where the display device100is the foldable display devices100aand100b, in some exemplary embodiments, the display device100is any flexible display device, such as a curved display device, a bent display device, a rollable display device, or a stretchable display device, etc. In other exemplary embodiments, the display device100is a flat, e.g., rigid, display device.

According to embodiments, the scan driver120provides the scan signals SS1, SS2and SS3to the plurality of pixels through the plurality of scan lines based on a scan control signal SCTRL received from the controller140. In some exemplary embodiments, the scan driver120sequentially provides the scan signals SS1, SS2and SS3to the plurality of pixels on a row-by-row basis. In some exemplary embodiments, the scan control signal SCTRL includes, but is not limited to, one or more scan start signals FLM1, FLM2and FLM3and one or more scan clock signals. In some exemplary embodiments, the scan driver120is integrated into or formed in a peripheral portion of the display panel110. In other exemplary embodiments, the scan driver120is implemented with one or more integrated circuits.

In some exemplary embodiments, the scan driver120receives first, second and third scan start signals FLM1, FLM2and FLM3from the controller140, and transmits first scan signals SS1to the first display region111in response to the first scan start signal FLM1, transmits second scan signals SS2to the intermediate display region113in response to the second scan start signal FLM2, and transmits third scan signals SS3to the second display region112in response to the third scan start signal FLM3. For example, as illustrated inFIG. 5, the scan driver120includes first stages121,122, . . . ,123that sequentially transmit the first scan signals SS1to the first display region111in response to the first scan start signal FLM1, second stages124, . . . ,125that sequentially transmit the second scan signals SS2to the intermediate display region113in response to the second scan start signal FLM2, and third stages126,127, . . . ,128that sequentially transmit the third scan signals SS3to the second display region112in response to the third scan start signal FLM3.

In some exemplary embodiments, as illustrated inFIG. 5, the scan driver120further includes a first switch191that selectively couples a last one123of the first stages121,122, . . . ,123and a first one124of the second stages124, . . . ,125, and a second switch193that selectively couples a last one125of the second stages124,125and a first one126of the third stages126,127, . . . ,128. The first switch191selectively transmits the second scan start signal FLM2or the first scan signal SS1(or a carry signal) of the last one123of the first stages121,122, . . . ,123to the first one124of the second stages124, . . .125, and the second switch193selectively transmits the third scan start signal FLM3or the second scan signal SS2(or a carry signal) of the last one125of the second stages124. . .125to the first one126of the third stages126,127, . . . ,128. For example, in a normal driving mode, or an entire driving mode, the first switch191transmits the first scan signal SS1of the last of the first stages123to the first of the second stages124, and the second switch193transmits the second scan signal SS2of the last of the second stages125to the first of the third stages126. In another example, when one of the first display region111and the intermediate display region113is driven, and the other is not driven, the second scan start signal FLM2has an on-level or an off-level, and the first switch191transmits the second scan start signal FLM2to the first one124of the second stages. Further, when one of the intermediate display region113and the second display region112is driven, and the other is not driven, the third scan start signal FLM3has an on-level or an off-level, the second switch193transmits the third scan start signal FLM3to the first one126of the third stages.

According to embodiments, the data driver130generates the data signals DS based on output image data ODAT and a data control signal DCTRL received from the controller140and transmits the data signals DS to the plurality of pixels through the plurality of data lines. In some exemplary embodiments, the data control signal DCTRL includes, but is not limited to an output data enable signal, a horizontal start signal and a load signal. In some exemplary embodiments, the data driver130and the controller140are implemented with a single integrated circuit, and the integrated circuit is referred to as a liming controller embedded data driver (TED). In other exemplary embodiments, the data driver130and the controller140are implemented with separate integrated circuits.

According to embodiments, the controller140, such as a timing controller), receives input image data IDAT and a control signal CTRL from an external host processor, such as a graphic processing unit (GPU) or a graphics card. The control signal CTRL includes a mode signal SMODE that indicates a driving mode of the display device100. For example, the mode signal SMODE indicates one of the normal driving mode, in which each of the first display region111, the intermediate display region113and the second display region112is driven, the first partial driving mode, in which the first display region111is driven, or the second partial driving mode, in which the second display region112is driven. For example, the mode signal SMODE indicates the first partial driving mode when the first display region111is located at the front side as illustrated inFIG. 3A, and indicates the second partial driving mode when the second display region112is located at the front side as illustrated inFIG. 3B. In some exemplary embodiments, when the first and second display regions111and112display different images to different users, as illustrated inFIG. 3C, the mode signal SMODE, further indicates the third partial driving mode, in which both of the first and second display regions111and112are driven. In some exemplary embodiments, the control signal CTRL further includes, but is not limited to, a vertical synchronization signal, a horizontal synchronization signal, an input data enable signal, a master clock signal, etc. The controller140generates the output image data ODAT, the data control signal DCTRL and the scan control signal SCTRL based on the input image data IDAT and the control signal CTRL. The controller140controls an operation of the scan driver120by providing the scan control signal SCTRL to the scan driver120, and controls an operation of the data driver130by providing the output image data ODAT and the data control signal DCTRL to the data driver130.

According to embodiments, in a normal driving mode, the controller140receives, as the input image data IDAT, frame data FDAT for the entire display regions111,112and113of the display panel110. In some exemplary embodiments, the controller140receives, as the input image data IDAT, the first partial image data PDAT1for the first display region111in the first partial driving mode, and receives, as the input image data IDAT, the second partial image data PDAT2for the second display region112in the second partial driving mode. In other exemplary embodiments, the controller140receives, as the input image data IDAT in the first partial driving mode, the first partial image data PDAT1for the first display region111and black data for the intermediate display region113and the second display region112, and receives, as the input image data IDAT in the second partial driving mode, the second partial image data PDAT2for the second display region112and black data for the first display region111and the intermediate display region113. Further, in some exemplary embodiments, the controller140receives, as the input image data IDAT in the third partial driving mode, the first and second partial image data PDAT1and PDAT2for the first and second display regions111and112.

The controller140of the display device100according to exemplary embodiments generates, in the first partial driving mode in which the first display region111is driven, first gradation data GDAT1for the intermediate display region113based on first edge information EI1for a first edge region of the first display region111, and second degradation information DI2for a second edge region of the second display region112, and generates, in the second partial driving mode in which the second display region112is driven, second gradation data GDAT2for the intermediate display region113based on first degradation information DI1for the first edge region of the first display region111and second edge information EI2for the second edge region of the second display region112. In some exemplary embodiments, the controller140generates, in the third partial driving mode in which the first and second display regions111and112are driven, third gradation data for the intermediate display region113based on the first edge information EI1for the first edge region of the first display region111and the second edge information EI2for the second edge region of the second display region112. To perform these operations, the controller140includes a degradation information storage150, an edge information extractor160and a gradation image generator170.

According to embodiments, the degradation information storage150stores the first degradation information DI1for the first edge region within the first display region111that is adjacent to the intermediate display region113, and the second degradation information DI2for the second edge region within the second display region112that is adjacent to the intermediate display region113. According to exemplary embodiments, each of the first and second edge regions may include one pixel line coupled to one scan line (or one data line), a few pixel lines, or tens of pixel lines. Here, one pixel line may mean one line (e.g., one tow) of pixels coupled to the same scan line, or one line (e.g., one column) of pixels coupled to the same data line. The degradation information DI1represents an accumulated driving voltage for the first edge region, and the second degradation information DI2represents an accumulated driving voltage for the second edge region. In some exemplary embodiments, the first and second degradation information DI1and DI2is updated for each frame. In other exemplary embodiments, the first and second degradation information DI1and DI2is updated every L frames, where L is an integer greater than 0. In still other exemplary embodiments, accumulated gray values of each of the first and second degradation information DI1and DI2are sequentially selected every L frames, and a selected accumulated gray value is updated every L frames. For example, when each of the first and second degradation information DI1and DI2includes K accumulated gray values, where K is an integer greater than 1, the entirety of each of the first and second degradation information DI1and DI2is updated every L×K frames. In some exemplary embodiments, the degradation information storage150is a nonvolatile memory device, such as a flash memory device.

According to embodiments, in the first partial driving mode, the edge information extractor160receives the first partial image data PDAT1for the first display region111, and extracts the first edge information EI1for the first edge region from the first partial image data PDAT1. In the second partial driving mode, the edge information extractor160receives the second partial image data PDAT2for the second display region112, and extracts the second edge information EI2for the second edge region from second partial image data PDAT2. Here, the first edge information EH includes gray values for the first edge region in a current frame, and the second edge information EI2includes gray values for the second edge region in the current frame In some exemplary embodiments, each of the first and second edge regions includes M pixel lines (e.g., M rows of pixels coupled to M scan lines or M columns of pixels coupled to M data lines), where M is an integer greater than 0, and the edge information extractor160generates the first edge information EI1or the second edge information EI2for each row, i.e., corresponding to each data line or each scan line, by calculating an average of M input gray levels for the M pixel lines. In other exemplary embodiments, the edge information extractor160generates the first edge information EI1or the second edge information EI2for each row by extracting a maximum value of the M gray levels for the M pixel lines. In still other exemplary embodiments, the edge information extractor160generates the first edge information EI1or the second edge information EI2of each row by calculating a weighted average of the M gray levels for the M pixel lines with a weight that gradually or continuously decreases as a distance of each row from the intermediate display region113increases.

According to embodiments, in the first partial driving mode in which the first display region111is driven, the gradation image generator170generates the first gradation data GDAT1for the intermediate display region113based on the first edge information EI1of the first edge region of the first display region111and the second degradation information DI2of the second edge region of the second display region112. In some exemplary embodiments, the first gradation data GDAT1gradually or continuously change from a gray value represented by the first edge information EI1to a gray value represented by the second degradation information DI2along a first direction DR1from the first display region111to the second display region112with respect to each row. In other exemplary embodiments, the first gradation data GDAT1gradually or continuously change from the gray value represented by the first edge information EI1to the gray value represented by the second degradation information DI2along the first direction DR1on a block-by-block basis where each block includes two or more rows. In still other exemplary embodiments, the first gradation data GDAT1gradually or continuously change from a weighted moving average of the first edge information EI1to a weighted moving average of the second degradation information DI2along the first direction DR1. In the first partial driving mode, the controller140provides to the data driver130, as the output image data ODAT, the first partial image data PDAT1for the first display region111and the first gradation data GDAT1for the intermediate display region113. In the first partial driving mode, the data driver130provides the data signals DS that correspond to the first partial image data PDAT1to the first display region111, and provides the data signals DS that correspond to the first gradation data GDAT1to the intermediate display region113. Thus, as illustrated inFIG. 6A, in the first partial driving mode, even if the controller140receives, as the input image data IDAT, only the first partial image data PDAT1for the first display region111, the controller140outputs, as the output image data ODAT, the first partial image data PDAT1for the first display region111and the first gradation data GDAT1for the intermediate display region113. Accordingly, an image that corresponds to the first partial image data PDAT1can be displayed in the first display region111, and a first gradation image that corresponds to the first gradation data GDAT1can be displayed in the intermediate display region113.

According to embodiments, in the second partial driving mode in which the second display region112is driven, the gradation image generator170generates the second gradation data GDAT2for the intermediate display region113based on the first degradation information DI1of the first edge region of the first display region111and the second edge information EI2of the second edge region of the second display region112. In some exemplary embodiments, the second gradation data GDAT2gradually or continuously change from a gray value represented by the first degradation information DI1to a gray value represented by the second edge information HI2along the first direction DR1with respect to each pixel row. In other exemplary embodiments, the second gradation data GDAT2gradually or continuously change from the gray value represented by the first degradation information DI1to the gray value represented by the second edge information EI2along the first direction DR1on a block-by-block basis. In still other exemplary embodiments, the second gradation data GDAT2gradually or continuously change from a weighted moving average of the first degradation information DI1to a weighted moving average of the second edge information EI2along the first direction DR1. In the second partial driving mode, the controller140provides to the data driver130, as the output image data ODAT, the second partial image data PDAT2for the second display region112and the second gradation data GDAT2for the intermediate display region113. In the second partial driving mode, the data driver130provides to the second display region112, the data signals DS that correspond to the second partial image data PDAT2, and provides to the intermediate display region113, the data signals DS that correspond to the second gradation data GDAT2. Thus, as illustrated inFIG. 6B, in the second partial driving mode, even if the controller140receives, as the input image data IDAT, only the second partial image data PDAT2for the second display region112, the controller140outputs, as the output image data ODAT, the second partial image data PDAT2for the second display region112and the second gradation data GDAT2for the intermediate display region113. Accordingly, an image that corresponds to the second partial image data PDAT2can be displayed in the second display region112, and a second gradation image that corresponds to the second gradation data GDAT2can be displayed in the intermediate display region113.

When a white image is displayed in the first display region111for a long time without a gradation image, as represented by210inFIG. 7, a degradation degree of the first display region111is greater than a degradation degree of the intermediate display region113and the second display region112, as represented by230inFIG. 7. Thus, the first display region111and the intermediate display region113have a degradation deviation. In this case, if the display device100degraded as represented by230inFIG. 7operates in the normal driving mode, or the entire driving mode, to display a full white image in the entire display regions111,112and113of the display panel110, a luminance difference occurs between the first display region111and the intermediate display region113as represented by250inFIG. 7. Further, due to this luminance difference, an image sticking can be perceived by a user.

However, in the display device100according to exemplary embodiments, in the first partial driving mode in which an image is displayed in the first display region111, the intermediate display region113displays the gradation image based on the first gradation data GDAT1generated based on the first edge information EI1and the second degradation information DI2as represented by220inFIG. 7. Further, in the second partial driving mode in which an image is displayed in the second display region112, the intermediate display region113displays the gradation image based on the second gradation data GDAT2generated based on the first degradation information DI1and the second edge information EI2. Thus, even if the display device100according to exemplary embodiments operates in the first partial driving mode for a long time, or even if a degradation degree of the first display region111differs from a degradation degree of the second display region112, as represented by240inFIG. 7, no degradation deviation occurs between the first display region111and the intermediate display region113, and no degradation deviation occurs between the intermediate display region113and the second display region112. In this case, if the display device100according to exemplary embodiments degraded as represented by240inFIG. 7operates in the normal driving mode to display the full white image in the entire display regions111,112and113of the display panel110, no luminance difference occurs between the first display region111and the intermediate display region113and between the intermediate display region113and the second display region112, as represented by260inFIG. 7, and thus no image sticking is perceived by the user.

FIG. 8is a flowchart of a method of operating a display device according to exemplary embodiments,FIG. 9illustrates an example where degradation information is updated in a method ofFIG. 8,FIG. 10illustrates another example where degradation information is updated in a method ofFIG. 8,FIG. 11illustrates an example where edge information is generated in a method ofFIG. 8,FIG. 12illustrates another example where edge information is generated in a method ofFIG. 8,FIG. 13illustrates still another example where edge information is generated in a method ofFIG. 8, andFIG. 14illustrates an example where gradation data are generated based on edge information and degradation information in a method ofFIG. 8.

Referring toFIGS. 1 and 8, according to embodiments, a method of operating a display device100that includes a display panel110that includes a first display region111, a second display region112, and an intermediate display region113between the first display region111and the second display region112, includes the steps of storing first degradation information DI1for a first edge region within the first display region111that is adjacent to the intermediate display region113in a degradation information storage150(S310), and storing second degradation information DI2for a second edge region within the second display region112that is adjacent to the intermediate display region113in the degradation information storage150(S315). According to exemplary embodiments, each of the first and second edge regions may include one pixel line coupled to one scan line (or one data line), a few pixel lines, or tens of pixel lines. In some exemplary embodiments, the first and second degradation information DI1and DI2are updated every frame.

In other exemplary embodiments, the first and second degradation information DI1and DI2are updated every L frames, where L is an integer greater than 0. For example, as illustrated inFIG. 9, as illustrated inFIG. 9, the first degradation information DI1for the first edge region116is updated every L frames while the display device100operates in a normal driving mode in which the entire display regions111,112and113of the display panel110are driven, or in a first partial driving mode in which the first display region111is driven. For example, the first degradation information DI1for each pixel or each row is updated in a first frame by calculating an average of accumulated gray values represented by the first degradation information DI1and current gray values, such as 150, 78, 35, . . . , represented by current image data410for the first edge region116, is updated in an (L+1)-th frame by calculating an average of accumulated gray values represented by the first degradation information DI1and current gray values, such as 142, 65, 50, . . . represented by current image data420for the first edge region116, and is updated in a (2L+1)-th frame by calculating an average of accumulated gray values represented by the first degradation information DI1and current gray values, such as 19, 50, 130, . . . represented by current image data430for the first edge region116. Similarly, the second degradation information DI2for the second edge region117is updated every L frames while the display device100operates in the normal driving mode or in a second partial driving mode in which the second display region112is driven.

In still other exemplary embodiments, each of the first and second degradation information DI1and DI2includes K accumulated gray values, where K is an integer greater than 0, tire K accumulated gray values are sequentially selected or shifted by one pixel every L frames, and a selected one of the K accumulated gray values is updated every L frames. For example, as illustrated inFIG. 10, the first degradation information DI1for a first pixel or a first row is updated in a first frame by calculating an average of an accumulated gray value represented by the first degradation information DI1for the first pixel or the first row and a current gray value415, i.e.,150, represented by current image data410for the first edge region116. Similarly, the first degradation information DI1for a second pixel or a second row is updated in an (L+1)-th frame by calculating an average of an accumulated gray value represented by the first degradation information DI1for the second pixel or the second row and a current gray value425, i.e., 65, represented by current image data420for the first edge region116. Further, the first degradation information DI1for a third pixel or a third row is updated in a (2L+1)-th frame by calculating an average of an accumulated gray value represented by the first degradation information DI1for the third pixel or the third row and a current gray value435, i.e.,130, represented by current image data430for the first edge region116. In this manner, the entirety of each of the first and second degradation information DI1and DI2is updated per L×K frames.

According to embodiments, when the display device100operates in the normal driving mode in which the entire display regions111,112and113of the display panel110are driven (S320: NORMAL), the display device300receives frame data FDAT as input image data IDAT, and drives the entire display regions111,112and113of the display panel110based on the frame data FDAT (S330).

According to embodiments, when the display device100operates in the first driving mode in which the first display region111is driven (S320: FIRST PARTIAL), an edge information extractor160receives first partial image data PDAT1for the first display region111(S340), and extracts first edge information EI1for the first edge region from the first partial image data PDAT1(S345).

In some exemplary embodiments, the first edge region includes M pixel lines, where M is an integer greater than 0, and the edge information extractor160generates the first edge information EI1by calculating for each row an average of M gray levels represented by the first partial image data PDAT1for the M pixel lines. For example, as illustrated inFIG. 11, the first edge region116includes first through fourth pixel lines, and the edge information extractor160generates the first edge information EI1by calculating an average of first through fourth line data LD1, LD2, LD3and LD4for the first through fourth pixel lines in each row.

In other exemplary embodiments, the edge information extractor160generates the first edge information EI1for each row by extracting a maximum value of the M gray levels represented by the first partial image data PDAT1for the M pixel lines. For example, as illustrated inFIG. 12, the first edge region116includes first through fourth pixel lines, and the edge information extractor160generates the first edge information EI1by extracting a maximum of the first through fourth gray values of first through fourth line data LD1, LD2, LD3and LD4for the first through fourth pixel lines in each row.

In still other exemplary embodiments, the edge information extractor160generates the first edge information EI1for each row by calculating a weighted average of the M gray levels represented by the first partial image data PDAT1for the M pixel lines with a weight that gradually or continuously decreases as a distance from the intermediate display region increases. For example, as illustrated inFIG. 13, the first edge region116includes first through fourth pixel lines. For each row, the edge information extractor160calculates a sum of a product of first line data LD1and a first weight W1, a product of second line data LD2and a second weight W2, a product of third line data LD3and a third weight W3, and a product of fourth line data LD4and a fourth weight W4, and generates the first edge information fill by dividing the calculated sum by a sum of the first through fourth weights W1, W2W3and W4. In this case, the first through fourth weights W1, W2W3and W4decrease as a distance from the intermediate display region113increases. Thus, the fourth weight W4for the fourth line data LD4, which is closest to the intermediate display region113, has a relatively large value, and the first weight W1for the first line data LD1farthest from the intermediate display region113, has a relatively small value.

According to embodiments, in the first partial driving mode, a gradation image generator170generates first gradation data GDAT1for the intermediate display region113based on the first edge information EI1for the first edge region of the first display region111and the second degradation information DI2for the second edge region of the second display region112(S350).

In some exemplary embodiments, as illustrated inFIG. 14, the gradation image generator170generates the first gradation data GDAT1such that the first gradation data GDAT1for each row gradually or continuously change from a gray value represented by the first edge information EI1to a gray value represented by the second degradation information DI2, along a first direction DR1from the first display region111to the second display region112. For example, in a first row, when the first edge information EI1represents a gray value of 150 and the second degradation information DI2represents a gray value of 142, the first gradation data GDAT1represents 149, 148, . . . , 144 and 143. Further, in a second row, when the first edge information EI1represents a gray value of 78 and the second degradation information DI2represents a gray value of 65, the first gradation data GDAT1represents 77, 76, . . . , 67 and 66. Further, in a third row, when the first edge information EI1represents a gray value of 35 and the second degradation information DI2represents a gray value of 50, the first gradation data GDAT1represents 36, 37, . . . 48 and 49. Further, in a fourth row, when the first edge information EI1represents a gray value of 24 and the second degradation information DI2represents a gray value of 70, the first gradation data GDAT1represents 26, 28, . . . , 66 and 68. Further, in a fifth row, when the first edge information EI1represents a gray value of 135 and the second degradation information DI2represents a gray value of 201, the first gradation data GDAT1represents 137, 139, . . . , 197 and 199.

According to embodiments, in the first partial driving mode, the display device100drives the first display region111and the intermediate display region113based on the first partial image data PDAT1and the first gradation data GDAT1(S360). Accordingly, no degradation deviation occurs between the first display region111and the intermediate display region113, and between the intermediate display region113and the second display region112, and thus no image sticking is perceived by a user.

According to embodiments, when the display device100operates in the second driving mode in which the second display region112is driven (S320: SECOND PARTIAL), the edge information extractor160receives second partial image data PDAT2for the second display region112(S370), and extracts second edge information EI2for the second edge region from the second partial image data PDAT2(S375). According to exemplary embodiments, the edge information extractor160generates the second edge information EI2by using one of an average, a maximum value or a weighted average.

According to embodiments, in the second partial driving mode, the gradation image generator170generates second gradation data GDAT2for the intermediate display region113based on the first degradation information DI1for the first edge region of the first display region111and the second edge information EI2for the second edge region of the second display region112(S380). In some exemplary embodiments, the gradation image generator170generates the second gradation data GDAT2for each row such that the second gradation data GDAT2gradually or continuously change from a gray value represented by the first degradation information DI1to a gray value represented by the second edge information E22along the first direction DR1.

According to embodiments, in the second partial driving mode, the display device100drives the second display region112and the intermediate display region113based on the second partial image data PDAT2and the second gradation data GDAT2(S390). Accordingly, no degradation deviation occurs between the first display region111and the intermediate display region113, and between the intermediate display region113and the second display region112, and thus no image sticking is perceived by the user.

FIG. 15is a flowchart of a method of operating a display device according to exemplary embodiments, andFIG. 16illustrates an example where gradation data are generated based on edge information and degradation information in a method ofFIG. 15.

Referring toFIGS. 1 and 15, a method of operating a display device100that includes a display panel110that includes a first display region111, a second display region112, and an intermediate display region113between the first display region111and the second display region112, includes the step of storing first degradation information DI1for a first edge region of the first display region111and second degradation information DI2for a second edge region of the second display region112in a degradation information storage150(S510).

According to embodiments, when the display device100operates in a normal driving mode in which the entire display regions111,112and113of the display panel110are driven (S520: NORMAL), the display device100receives frame data FDAT as input image data IDAT, and drives the entire display regions111,112and113of the display panel110based on the frame data FDAT (S530).

According to embodiments, when the display device100operates in a first driving mode in which the first display region111is driven (S520: FIRST PARTIAL), an edge information extractor160receives first partial image data PDAT1for the first display region111(S540), and extracts first edge information EI1for the first edge region from the first partial image data PDAT1(S545). According to exemplary embodiments, the edge information extractor160generates the first edge information EI1by using one of an average, a maximum value or a weighted average.

According to embodiments, in the first partial driving mode, a gradation image generator170calculates a first edge block gray value by calculating an average of N consecutive gray values represented by the first edge information EI1(S552), where N is an integer greater than 1, calculates a second degradation block gray value by calculating an average of N consecutive gray values represented by the second degradation information DI2(S554), and generates first gradation data GDAT1that gradually or continuously change from the first edge block gray value to the second degradation block gray value along the first direction DR1from the first display region111to the second display region112(S556). That is, the first gradation data GDAT1is generated for a unit of a block having N rows.

For example, according to embodiments, as illustrated inFIG. 16, the gradation image generator170generates the first gradation data GDAT1for a unit of a block having four rows. For example, in the first through fourth rows, when the first edge information EI1represents gray values of 150, 78, 35 and 24, and the second edge information DI2represents gray values of 142, 65, 50 and 70, the gradation image generator170calculates the first edge block gray value EBG1of 72 by calculating an average of 150, 78, 35 and 24, calculates the second degradation block gray value DBG2of 82 by calculating an average of 142, 65, 50 and 70, and generate the first gradation data GDAT1representing 73, 74, . . . , 80 and 81 in each of the first through fourth rows. In this manner, the first gradation data GDAT1is generated in units of a block having four rows. AlthoughFIG. 16illustrates an example where each block includes four rows and one column, embodiments are not limited thereto, and according to other exemplary embodiments, each block may have one or more rows and one or more columns.

According to embodiments, in the first partial driving mode, the display device100drive the first display region111and the intermediate display region113based on the first partial image data PDAT1and the first gradation data GDAT1(S560). Accordingly, no degradation deviation occurs between the first display region111and the intermediate display region113, and between the intermediate display region113and the second display region112, and thus no an image sticking is perceived by a user.

According to embodiments, when the display device100operates in the second driving mode in which the second display region112is driven (S520: SECOND PARTIAL), the edge information extractor160receives second partial image data PDAT2for the second display region112(S570), and extracts second edge information EI2for the second edge region from the second partial image data PDAT2(S575). According to exemplary embodiments, the edge information extractor160generates the second edge information EI2by using one of an average, a maximum value or a weighted average.

According to embodiments, in the second partial driving mode, the gradation image generator170calculates a first degradation block gray value by calculating an average of N consecutive gray values represented by the final degradation information DU (S582), calculates a second edge block gray value by calculating an average of N consecutive gray values represented by the second edge information EI2(S584), and generates second gradation data GDAT2such that the second gradation data GDAT2gradually or continuously change from the first degradation block gray value to the second edge block gray value along the first direction DR1(S586). That is, the second gradation data GDAT2is generated for units of a block having N rows.

According to embodiments, in the second partial driving mode, the display device100drives the second display region112and the intermediate display region113based on the second partial image data PDAT2and the second gradation data GDAT2(S590). Accordingly, no degradation deviation occurs between the first display region111and the intermediate display region113, and between the intermediate display region113and the second display region112, and thus no image sticking is perceived by the user.

FIG. 17is a flowchart of a method of operating a display device according to exemplary embodiments, andFIG. 18illustrates an example where gradation data are generated based on edge information and degradation information in a method ofFIG. 17.

Referring toFIGS. 1 and 17, According to embodiments, a method of operating a display device100that includes a display panel110that includes a first display region111, a second display region112, and an intermediate display region113between the first display region111and the second display region112, includes a step of storing first degradation information DI1for a first edge region of the first display region111and second degradation information DI2for a second edge region of the second display region112in a degradation information storage150(S610).

According to embodiments, when the display device100operates in a normal driving mode in which the entire display regions111,112and113of the display panel110are driven (S620: NORMAL), the display device100receives frame data FDAT as input image data IDAT, and drives the entire display regions111,112and113of the display panel110based on the frame data FDAT (S630).

According to embodiments, when the display device100operates in a first driving mode in which the first display region111is driven (S620: FIRST PARTIAL), an edge information extractor160receives first partial image data PDAT1for the first display region111(S640), and extracts first edge information EI1for the first edge region from the first partial image data PDAT1(S645). According to exemplary embodiments, the edge information extractor160generates the first edge information EI1by using one of an average, a maximum value or a weighted average.

According to embodiments, in the first partial driving mode, a gradation image generator170calculates a first edge weighted moving average by calculating a weighted moving average of N consecutive gray values represented by the first edge information EI1(S652), where N is an integer greater than 1, calculates a second degradation weighted moving average by calculating a weighted moving average of N consecutive gray values represented by the second degradation information DI2(S654), and generates first gradation data GDAT1such that the first gradation data GDAT1gradually or continuously change from the first edge weighted moving average to the second degradation weighted moving average along the first direction DR1from the first display region to the second display region (S656).

For example, according to embodiments, as illustrated inFIG. 18, the gradation image generator170calculates the first edge weighted moving average EWMA1by applying a weighted moving average window WMAW with weights of 1, 2, 4, 2 and 1 to the first edge information EI1. For example, when the first edge information EI1represents 150, 78, 35, 24, 135, . . . , the gradation image generator170calculates the first edge weighted moving average EWMA1representing 113, 78, 63 . . . . For example, the first edge weighted moving average EWMA1for a first row may be calculated by using an equation, “(150*4+78*2+35*1)/(4+2+1)*113”, the first edge weighted moving average EWMA1for a second row may be calculated by using an equation, “(150*2+78*4+35*2+24*1)/(2+4+2+1)−78”, and the first edge weighted moving average EWMA1for a third row may be calculated by using an equation, “(150*1+78*2+35*4+24*2+135*1)/(1+2+4+2+1)+63” Further, the gradation image generator170calculates the second degradation weighted moving average DWMA2by applying the weighted moving average window WMAW with the weights of 1, 2, 4, 2 and 1 to the first edge information EI1. For example, when the second degradation information DI2represents 142, 65, 50, 70, 201, . . . , the gradation image generator170calculates the second degradation weighted moving average DWMA2representing 107, 79, 81 . . . . For example, the second degradation weighted moving average DWMA2for the first row may be calculated by using an equation, “(142*4−65*2+50*1)/(4+2+1)=107”, the second degradation weighted moving average DWMA2for the second row may be calculated by using an equation, “(142*2+65*4+50*2+70*1)/(2+4+2+1)=79”, and the second degradation weighted moving average DWMA2for the third row may be calculated by using an equation. “(142*1+65*2+50*4+70*2+201*1)/(1+2+4+2+1)=81” In this case, the gradation image generator170generates the first gradation data GDAT1representing 112, 111, . . . , 109 and 108 in the first row, representing 78, 78, . . . , 79 and 79 in the second row, and representing 64, 65, . . . , 79 and 80 in the third row.

According to embodiments, in the first partial driving mode, the display device100drives the first display region111and the intermediate display region113based on the first partial image data PDAT1and the first gradation data GDAT1(S660). Accordingly, no degradation deviation occurs between the first display region111and the intermediate display region113, and between the intermediate display region113and the second display region112, and thus no image sticking is perceived by a user.

According to embodiments, when the display device100operates in the second driving mode in which the second display region112is driven (S620: SECOND PARTIAL), the edge information extractor160receives second partial image data PDAT2for the second display region112(S670), and extracts second edge information EI2for the second edge region from the second partial image data PDAT2(S675). According to exemplary embodiments, the edge information extractor160generates the second edge information EI2by using one of an average, a maximum value or a weighted average.

According to embodiments, in the second partial driving mode, the gradation image generator170calculates a first degradation weighted moving average by calculating a weighted moving average of N consecutive gray values represented by the first degradation information DI1(S682), calculates a second edge weighted moving average by calculating a weighted moving average of N consecutive gray values represented by the second edge information EI2(S684), and generates second gradation data GDAT2such that the second gradation data GDAT2gradually or continuously change from the first degradation weighted moving average to the second edge weighted average along the first direction DR1(S686).

According to embodiments, in the second partial driving mode, the display device100drives the second display region112and the intermediate display region113based on the second partial image data PDAT2and the second gradation data GDAT2(S690). Accordingly, no degradation deviation occurs between the first display region111and the intermediate display region113, and between the intermediate display region113and the second display region112, and thus no image sticking is perceived by the user.

FIG. 19illustrates an example where gradation data are generated with respect to each of a red sub-pixel, a green sub-pixel and a blue sub-pixel in a display device according to exemplary embodiments.

Referring toFIGS. 1 and 19, according to embodiments, each pixel PX of a display panel110includes a red sub-pixel RSP, a green sub-pixel GSP and a blue sub-pixel BSP. The gradation image generator170generates first gradation data GDAT1with respect to each of the red sub-pixel RSP, the green sub-pixel GSP and the blue sub-pixel BSP in the first partial driving mode, and generate second gradation data GDAT2with respect to each of the red sub-pixel RSP, the green sub-pixel GSP and the blue sub-pixel BSP in the second partial driving mode.

For example, according to embodiments. First edge information EI1includes first red edge information REI1for the red sub-pixel RSP, first green edge information GEI1for the green sub-pixel GSP, and first blue edge information BEI1for the blue sub-pixel BSP. Further, second degradation information DI2includes second red degradation information RDI2for the red sub-pixel RSP, second green degradation information GDI2for the green sub-pixel GSP, and second blue degradation information BDI2for the blue sub-pixel BSP. The gradation image generator170generates, as the first gradation data GDAT1, first red gradation data RGDAT1for the red sub-pixel RSP based on the first red edge information REI1and the second red degradation information RDI2, first green gradation data GGDAT1for the green sub-pixel GSP based on the first green edge information GEI1and the second green degradation information GDI2, and first blue gradation data BGDAT1for the blue sub-pixel BSP based on lire first blue edge information BEI1and the second blue degradation information BDI2.

FIG. 20illustrates an example where gradation data are generated which have the same gray value with respect to a red sub-pixel, a green sub-pixel and a blue sub-pixel in a display device according to exemplary embodiments.

Referring toFIGS. 1 and 20, according to embodiments, each pixel PX of a display panel110includes a red sub-pixel RSP, a green sub-pixel GSP and a blue sub-pixel BSP. The gradation image generator170generates first gradation data GDAT1that represents a first same gray value with respect to the red sub-pixel RSP, the green sub-pixel GSP and the blue sub-pixel BSP in the same pixel PX in the first partial driving mode, and generates second gradation data GDAT2that represents a second same gray value with respect to the red sub-pixel RSP, the green sub-pixel GSP and the blue sub-pixel BSP in the same pixel PX in the second partial driving mode. For example, as illustrated inFIG. 20, first red gradation data RGDAT1, first green gradation data GGDAT1and first blue gradation data BGDAT1in the first gradation data GDAT1represent the same gray value with respect to the red sub-pixel RSP, the green sub-pixel GSP and the blue sub-pixel BSP in each pixel PX.

FIG. 21illustrates an electronic device that includes a display device according to exemplary embodiments.

Referring toFIG. 21, an electronic device1000according to exemplary embodiments includes a sensor1010, a host processor1030and a display device1050. In some exemplary embodiments, the electronic device1000further includes a memory device, a storage device, an input/output (I/O) device, a power supply, etc.

According to embodiments, the sensor1010senses an operating state or deformation of the display device1050, and provides a sense signal SSENSE that is indicative of the deformation to the host processor1030. For example, the sense signal SSENSE may indicate that the display device1050is not folded, may indicate that the display device1050is folded such that a first display region is located in a front side and a second display region is located in a back side as illustrated inFIG. 3A, or may indicate that the display device1050is folded such that the first display region is located in the back side and the second display region is located in the front side as illustrated inFIG. 3B.

According to embodiments, the host processor1030can perform various computing functions or tasks. The host processor1030may be one of an application processor (AP) that includes a graphics processing unit (GPU), a central processing unit (CPU), or a micro processor, etc. The host processor1030provides a control signal CTRL, and input image data IDAT to the display device1050. For example, the host processor1030may provide to the display device1050a mode signal SMODE that indicates a normal driving mode and frame data FDAT in response to the sense signal SSENSE indicating that the display device1050is not folded, may provide to the display device1050the mode signal SMODE that indicates a first partial driving mode in which the first display region is driven and first partial image data PDAT1in response to the sense signal SSENSE indicating that the display device1050is folded such that the first display region is located in the front side and the second display region is located in the back side, and may provide to the display device1050the mode signal SMODE that indicates a second partial driving mode in which the second display region is driven and second partial image data PDAT2in response to the sense signal SSENSE indicating that the display device1050is folded such that the first display region is located in the back side and the second display region is located in the front side.

According to embodiments, the display device1050displays an image based on the control signal CTRL and input image data IDAT. The display device1050stores first degradation information for a first edge region of the first display region and second degradation information for a second edge region of the second display region. In response to the mode signal SMODE indicating the first partial driving mode, the display device1050generates first gradation data for an intermediate display region based on first edge information for the first edge region and the second degradation information for the second edge region, displays an image that corresponds to the first partial image data PDAT1in the first display region, and displays a gradation image that corresponds to the first gradation data in the intermediate display region. Further, in response to the mode signal SMODE indicating the second partial driving mode, the display device1050generates second gradation data for the intermediate display region based on the first degradation information for the first edge region and second edge information for the second edge region, displays an image that corresponds to the second partial image data PDAT2in the second display region, and displays a gradation image that corresponds to the second gradation data in the intermediate display region. Accordingly, in the display device1050according to exemplary embodiments, no image sticking is perceived between the first edge region and the intermediate display region and between the intermediate display region and the second edge region.

Embodiments of the inventive concepts can be implemented in any display device1050, and any electronic device1000that includes the display device1050. For example, embodiments of the inventive concepts can be implemented in a mobile phone, a smart phone, a wearable electronic device, a tablet computer, a television (TV), a digital TV, a 3D TV, a personal computer (PC), a home appliance, a laptop computer, a personal digital assistant (PDA), a portable multimedia player (PMP), a digital camera, a music player, a portable game console, or a navigation device, etc.