Flexible display device for detecting deformation position and deformation amount and electronic device including the same

A flexible display device includes: a flexible display panel including a plurality of pixels, a power supply line coupled to the plurality of pixels, and at least one measuring line; a power management circuit, which supplies a power supply voltage to the plurality of pixels through the power supply line; and a display driver, which drives the flexible display panel. The display driver senses a resistance of the at least one measuring line, and detects at least one of a deformation position and a deformation amount of the flexible display panel based on the sensed resistance.

This application claims priority to Korean Patent Application No. 10-2021-0144861, filed on Oct. 27, 2021, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which in its entirety is herein incorporated by reference.

BACKGROUND

Embodiments relate to a display device, and more particularly to a flexible display device, and an electronic device including the flexible display device.

2. Description of the Related Art

A flexible display device, such as a foldable display device or a rollable display device having a flexible display panel, at least a portion of which is deformable (e.g., foldable or bendable), has been developed. In the flexible display device, the flexible display panel may be deformed by a user.

However, in a case where the flexible display panel is deformed (e.g., folded or bent), resistances of lines (e.g., a power supply line) within the flexible display panel may be increased. By this increase of the resistances, luminance uniformity of the flexible display panel may be decreased, and color deviation may occur in an image displayed at the flexible display panel.

SUMMARY

Some embodiments provide a flexible display device capable of detecting at least one of a deformation position and a deformation amount

Some embodiments provide an electronic device including the flexible display device.

According to embodiments, there is provided a flexible display device including: a flexible display panel, a power management circuit and a display driver. The flexible display panel includes a plurality of pixels, a power supply line coupled to the plurality of pixels, and at least one measuring line. The power management circuit supplies a power supply voltage to the plurality of pixels through the power supply line. The display driver drives the flexible display panel. The display driver senses a resistance of the at least one measuring line, and detects at least one of a deformation position and a deformation amount of the flexible display panel based on the sensed resistance.

In embodiments, the display driver may include a resistance-deformation amount model storage, which stores resistance-deformation amount model information about a deformation amount value of the flexible display panel corresponding to a resistance value of the at least one measuring line.

In embodiments, the display driver may include a resistance-voltage drop model storage, which stores resistance-voltage drop model information about a voltage drop amount of the power supply voltage at the power supply line corresponding to a resistance value of the at least one measuring line.

In embodiments, the display driver may determine the voltage drop amount of the power supply voltage corresponding to the sensed resistance of the at least one measuring line by using the resistance-voltage drop model information, and the power management circuit may increase a voltage level of the power supply voltage by the determined voltage drop amount.

In embodiments, the flexible display panel may be a foldable display panel having a fixed bendable position. The flexible display panel may include, as the at least one measuring line, an outer measuring line surrounding a display region of the flexible display panel.

In embodiments, the display driver may apply a current to a first end of the outer measuring line, and may sense a resistance of the outer measuring line by measuring a voltage of a second end of the outer measuring line. The display driver may detect the deformation amount of the flexible display panel based on the resistance of the outer measuring line.

In embodiments, the flexible display panel may be a foldable display panel having a fixed bendable position. The flexible display panel may include, as the at least one measuring line, a first measuring line extending from the display driver to a first position that is closer to the display driver than the bendable position, and a second measuring line extending from the display driver to a second position that is farther from the display driver than the bendable position. The first and second positions are located in the flexible display panel

In embodiments, the display driver may sense a first resistance of the first measuring line and a second resistance of the second measuring line, and may detect the deformation amount of the flexible display panel based on a difference between the first resistance of the first measuring line and the second resistance of the second measuring line.

In embodiments, the flexible display panel may be a foldable display panel having a fixed first bendable position and a fixed second bendable position. The flexible display panel may include, as the at least one measuring line, a first measuring line extending from the display driver to a first position that is closer to the display driver than the first bendable position, a second measuring line extending from the display driver to a second position that is farther from the display driver than the first bendable position and closer to the display driver than the second bendable position, and a third measuring line extending from the display driver to a third position that is farther from the display driver than the second bendable position. The first, second, third positions are located in the flexible display panel.

In embodiments, the display driver may sense a first resistance of the first measuring line, a second resistance of the second measuring line and a third resistance of the third measuring line. Based on a first difference between the first resistance of the first measuring line and the second resistance of the second measuring line, the display driver may detect whether the flexible display panel is bent at the first bendable position, and may detect the deformation amount at the first bendable position. Based on a second difference between the second resistance of the second measuring line and the third resistance of the third measuring line, the display driver may detect whether the flexible display panel is bent at the second bendable position, and may detect the deformation amount at the second bendable position.

In embodiments, the flexible display panel may be a foldable display panel that is able to be bent at any position. The flexible display panel may include, as the at least one measuring line, a plurality of measuring lines extending from the display driver to different positions therein, respectively.

In embodiments, the display driver may sense resistances of the plurality of measuring lines. In a case where a difference between the resistances of two measuring lines extending to adjacent two positions among the plurality of measuring lines is greater than a reference resistance, the display driver may determine that the deformation position of the flexible display panel is between the adjacent two positions.

In embodiments, the display driver may detect the deformation amount at the deformation position based on the difference between the resistances of the two measuring lines.

In embodiments, the display driver may include a resistance-data compensation model storage, which stores resistance-data compensation model information about a data compensation value corresponding to a resistance value of the at least one measuring line.

In embodiments, the display driver may compensate input image data based on the sensed resistance of the at least one measuring line and the resistance-data compensation model information.

In embodiments, the display driver may determine the data compensation value corresponding to the sensed resistance of the at least one measuring line based on the resistance-data compensation model information, and may compensate input image data by adding the data compensation value to a gray level represented by the input image data.

In embodiments, the flexible display panel may include, as the at least one measuring line, a plurality of measuring lines extending from the display driver to different positions therein respectively. The display driver may sense resistances of the plurality of measuring lines. In a case where a difference between the resistances of two measuring lines extending to adjacent two positions of the different positions among the plurality of measuring lines is greater than a reference resistance, the display driver may compensate input image data by gradually increasing the input image data for pixels of the plurality of pixels located between the adjacent two positions and located farther from the display driver than the adjacent two positions.

According to embodiments, there is provided a flexible display device including a flexible display panel, a power management circuit, and a power management circuit. The flexible display panel includes a plurality of pixels, and a power supply line coupled to the plurality of pixels. The power management circuit supplies a power supply voltage to the plurality of pixels through the power supply line. The display driver drives the flexible display panel. The flexible display panel further includes a plurality of measuring lines extending from the display driver to different positions, respectively. The display driver senses resistances of the plurality of measuring lines, and detects at least one of a deformation position and a deformation amount of the flexible display panel based on differences of the resistances of the plurality of measuring lines.

According to embodiments, there is provided an electronic device including a host processor, which generates input image data, and a flexible display device, which displays an image based on the input image data. The flexible display device includes: a flexible display panel including a plurality of pixels, a power supply line coupled to the plurality of pixels, and at least one measuring line; a power management circuit, which supplies a power supply voltage to the plurality of pixels through the power supply line; and a display driver, which drives the flexible display panel. The display driver senses a resistance of the at least one measuring line, detects at least one of a deformation position and a deformation amount of the flexible display panel based on the sensed resistance, and provides deformation information representing the at least one of the deformation position and the deformation amount to the host processor.

In embodiments, in case where the deformation information indicates that the flexible display panel is deformed while the flexible display panel displays a moving image, the host processor adjusts the input image data based on the deformation information such that a region of the flexible display panel displaying the moving image is changed.

As described above, in a flexible display device and an electronic device including the flexible display device according to embodiments, a display driver may sense a resistance of at least one measuring line, and may detect at least one of a deformation position and a deformation amount of a flexible display panel based on the sensed resistance. Accordingly, the deformation position and/or the deformation amount of the flexible display panel may be efficiently and accurately detected.

Further, in the flexible display device and the electronic device according to embodiments, a power supply voltage or input image data may be compensated based on the deformation position and/or the deformation amount. Accordingly, even if the flexible display panel is deformed, deterioration of luminance uniformity and color deviation of the flexible display panel may be effectively prevented or reduced.

DETAILED DESCRIPTION

FIG.1is a block diagram illustrating a flexible display device according to embodiments,FIG.2Ais a diagram illustrating an example of a resistance-deformation amount model,FIG.2Bis a diagram illustrating another example of a resistance-deformation amount model,FIG.3Ais a diagram illustrating an example of a resistance-voltage drop model, andFIG.3Bis a diagram illustrating another example of a resistance-voltage drop model according to an embodiment.

Referring toFIG.1, a flexible display device100according to embodiments may include a flexible display panel110, a power management circuit120that supplies a power supply voltage ELVDD to the flexible display panel110, and a display driver130that drives the flexible display panel110. The display driver130may include a data driver140that provides data signals DS to the flexible display panel110, and a controller160that controls an operation of the flexible display device100. In some embodiments, the flexible display device100may further include a scan driver150that provides scan signals SS to the flexible display panel110.

The flexible display panel110may include a plurality of pixels PX in a display region DR therein (SeeFIG.4). In some embodiments, each pixel PX may include a light emitting element, and the flexible display panel110may be a light emitting display panel. For example, the flexible display panel110may be, but not limited to, an organic light emitting diode (“OLED”) display panel, a quantum dot (“QD”) display panel, or the like. In other embodiments, the flexible display panel110may be a liquid crystal display (“LCD”) panel, or any other suitable display panel.

The flexible display panel110may further include a power supply line coupled to the plurality of pixels PX. The power supply line may be a line for supplying the power supply voltage ELVDD (e.g., a high-power supply voltage) generated by the power management circuit120to the plurality of pixels PX. In some embodiments, the power supply line may have, but not limited to, a mesh structure.

The flexible display panel110may further include at least one measuring line ML. A resistance of the at least one measuring line ML may be sensed or measured to detect a deformation position and/or a deformation amount (or a deformation degree) of the flexible display panel110. In some embodiments, as illustrated inFIG.4, the at least one measuring line ML may be an outer measuring line OML surrounding the display region DR in which the plurality of pixels PX is disposed. In other embodiments, as illustrated inFIGS.7,9and12, the at least one measuring line ML may include a plurality of measuring lines ML1, ML2, ML3, . . . , MLN−1 and MLN extending to a plurality of positions P1, P2, P3, . . . , PN−1 and PN, respectively.

The power management circuit120may supply the power supply voltage ELVDD to the plurality of pixels PX through the power supply line. In some embodiments, the power management circuit120may adjust a voltage level of the power supply voltage ELVDD in response to a power control signal PCTRL received from the controller160. In some embodiments, the power management circuit120may be implemented with an integrated circuit, and the integrated circuit may be referred to as a power management integrated circuit (“PMIC”). In other embodiments, the power management circuit120may be included in the display driver130or the controller160.

The data driver140may generate the data signals DS based on output image data ODAT and a data control signal DCTRL received from the controller160, and may provide the data signals DS to the plurality of pixels PX through a plurality of data lines. In some embodiments, the data control signal DCTRL may include, but not limited to, a data enable signal, a horizontal start signal and a load signal. In some embodiments, the data driver140and the controller160may be implemented with a single integrated circuit, and the single integrated circuit may be referred to as a timing controller embedded data driver (“TED”) integrated circuit. In other embodiments, the data driver140and the controller160may be implemented with separate integrated circuits from each other.

The scan driver150may generate the scan signals SS based on a scan control signal SCTRL received from the controller160, and may sequentially provide the scan signals SS to the plurality of pixels PX on a row-by-row basis through a plurality of scan lines. In some embodiments, the scan control signal SCTRL may include, but not limited to, a scan start signal and a scan clock signal. In some embodiments, as illustrated inFIG.1, the scan driver150may be integrated or disposed in a peripheral region adjacent to (or within) the display region of the flexible display panel110. In other embodiments, the scan driver150may be implemented with one or more integrated circuits.

The controller160(e.g., a timing controller (“TCON”)) may receive input image data IDAT and a control signal CTRL from an external host processor (e.g., an application processor (“AP”), a graphics processing unit (“GPU”) or a graphics card). In some embodiments, the input image data IDAT may be, but not limited to, RGB image data including red image data, green image data and blue image data. In some embodiments, the control signal CTRL may include, but not limited to, a vertical synchronization signal, a horizontal synchronization signal, an input data enable signal, a master clock signal, etc. The controller160may generate the output image data ODAT based on the input image data IDAT, and may generate the data control signal DCTRL and the scan control signal SCTRL based on the control signal CTRL. The controller160may control an operation of the data driver140by providing the output image data ODAT and the data control signal DCTRL to the data driver140, and may control an operation of the scan driver150by providing the scan control signal SCTRL to the scan driver150.

In the flexible display device100according to embodiments, the display driver130(or the controller160) may sense (or measure) the resistance of the at least one measuring line ML of the flexible display panel110. For example, the display driver130(or the controller160) may apply a current IM to a first end of the measuring line ML, may measure a voltage VM of a second end of the measuring line ML (or a voltage between the first end and a second end of the measuring line ML), and may determine the resistance of the measuring line ML based on the current IM and the voltage VM (e.g., using ohm's law).

Further, the display driver130(or the controller160) may detect at least one of the deformation position and the deformation amount (or the deformation degree) of the flexible display panel110based on the sensed resistance of the at least one measuring line ML. In some embodiments, the display driver130(or the controller160) may generate deformation information DI representing at least one of the deformation position and the deformation amount, and may provide the deformation information DI to the external host processor.

In some embodiments, the flexible display panel110may have one or more fixed bendable positions, and the display driver130may determine one of the fixed bendable positions as the deformation position of the flexible display panel110based on the sensed resistance of the at least one measuring line ML. In other embodiments, the flexible display panel110may include, as the at least one measuring line ML, the plurality of measuring lines extending from the display driver130to different positions. In this case, the display driver130may determine two measuring lines extending to adjacent two positions, respectively, and having a resistance difference greater than a reference resistance therebetween among the plurality of measuring lines, and may determine that the deformation position of the flexible display panel110is between the adjacent two positions.

In some embodiments, the display driver130may include a resistance-deformation amount model storage170that stores resistance-deformation amount model information about a deformation amount value of the flexible display panel110corresponding to a resistance value (or a resistance difference value) of the at least one measuring line ML. The display driver130may determine the deformation amount of the flexible display panel110corresponding to the sensed resistance of the at least one measuring line ML by using the resistance-deformation amount model information stored in the resistance-deformation amount model storage170. The resistance-deformation amount model information may be stored as various forms, for example, a lookup table or an equation.

In some embodiments, the resistance-deformation amount model information stored in the resistance-deformation amount model storage170may be determined through experiments for the flexible display device100. For example, as illustrated inFIG.2A, the resistance-deformation amount model information stored in the resistance-deformation amount model storage170may represent a linear relationship210between the resistance value (or the resistance difference value) greater than the reference resistance REFR and the deformation amount value. In another example, as illustrated inFIG.2B, the resistance-deformation amount model information stored in the resistance-deformation amount model storage170may represent a nonlinear relationship220between the resistance value (or the resistance difference value) greater than the reference resistance REFR and the deformation amount value. Further, in some embodiments, the resistance-deformation amount model storage170may be implemented in a form of a lookup table that outputs a corresponding deformation amount value in response to each resistance value (or each resistance difference value), but a configuration of the resistance-deformation amount model storage170is not limited to the lookup table.

Further, the flexible display device100according to embodiments may compensate the power supply voltage ELVDD supplied to the flexible display panel110based on the sensed resistance of the at least one measuring line ML. In a case where the flexible display panel110is deformed, resistances of lines of the flexible display panel110, for example a resistance of the power supply line for supplying the power supply voltage ELVDD may be increased, and a voltage drop of the power supply voltage ELVDD may be increased by the increase of the resistance. However, in the case where the flexible display panel110is deformed, the flexible display device100according to embodiments may increase the power supply voltage ELVDD to compensate for the voltage drop of the power supply voltage ELVDD. Accordingly, even if the flexible display panel110is deformed and the voltage drop of the power supply voltage ELVDD is increased, deterioration of luminance uniformity and color deviation of the flexible display panel110may be prevented or reduced. As used herein, “deformed” means folded, bent, rolled, curved or stretched.

In some embodiments, the display driver130may include a resistance-voltage drop model storage180that stores resistance-voltage drop model information about a voltage drop amount of the power supply voltage ELVDD at the power supply line corresponding to the resistance value (or the resistance difference value) of the at least one measuring line ML. The display driver130may determine the voltage drop amount of the power supply voltage ELVDD corresponding to the sensed resistance of the at least one measuring line ML by using the resistance-voltage drop model information stored in the resistance-voltage drop model storage180, and may provide the power control signal PCTRL representing an increased voltage level of the power supply voltage ELVDD to the power management circuit120to increase a voltage level of the power supply voltage ELVDD by the determined voltage drop amount. The power management circuit120may increase the voltage level of the power supply voltage ELVDD by the determined voltage drop amount in response to the power control signal PCTRL. The resistance-voltage drop model information may be stored as various forms, for example, a lookup table or an equation.

In some embodiments, the resistance-voltage drop model information stored in the resistance-voltage drop model storage180may be determined through experiments for the flexible display device100. For example, as illustrated inFIG.3A, the resistance-voltage drop model information stored in the resistance-voltage drop model storage180may represent a linear relationship260between the resistance value (or the resistance difference value) greater than the reference resistance REFR and the voltage drop amount of the power supply voltage ELVDD. In another example, as illustrated inFIG.3B, the resistance-voltage drop model information stored in the resistance-voltage drop model storage180may represent a nonlinear relationship270between the resistance value (or the resistance difference value) greater than the reference resistance REFR and the voltage drop amount of the power supply voltage ELVDD. Further, in some embodiments, the resistance-voltage drop model storage180may be implemented in a form of a lookup table that outputs a corresponding voltage drop amount in response to each resistance value (or each resistance difference value), but a configuration of the resistance-voltage drop model storage180is not limited to the lookup table.

As described above, in the flexible display device100according to embodiments, the display driver130may sense the resistance of the at least one measuring line ML, and may detect at least one of the deformation position and the deformation amount of the flexible display panel110based on the sensed resistance of the at least one measuring line ML. Accordingly, the deformation position and/or the deformation amount of the flexible display panel110may be efficiently and accurately detected. Further, in the flexible display device100according to embodiments, the power supply voltage ELVDD may be compensated based on the deformation position and/or the deformation amount. Accordingly, even if the flexible display panel110is deformed, deterioration of luminance uniformity and color deviation of the flexible display panel110may be prevented or reduced.

FIG.4is a diagram illustrating a flexible display device having one fixed bendable position according to embodiments,FIG.5Ais a diagram illustrating an example of a flexible display device according to embodiments,FIG.5Bis a diagram illustrating another example of a flexible display device according to embodiments, andFIG.6is a diagram illustrating an example of resistances of an outer measuring line before and after bending of a flexible display panel.

Referring toFIG.4, a flexible display device300according to embodiments may include a flexible display panel310, a power management circuit320that supplies a power supply voltage ELVDD to the flexible display panel310, and a display driver330that drives the flexible display panel310.

The flexible display panel310may include a plurality of pixels formed in a display region DR, and a power supply line ELVDDL coupled to the plurality of pixels. The power management circuit320may supply the power supply voltage ELVDD to the plurality of pixels through the power supply line ELVDDL. In some embodiments, the power supply line ELVDDL may have a mesh structure.

In some embodiments, the flexible display panel310may be a foldable display panel having a fixed bendable position BP, and the flexible display device300may be a foldable display device. For example, as illustrated inFIG.5A, the flexible display device300may be an in-foldable display device300aincluding the foldable display panel310athat is folded at the fixed bendable position BPa such that portions of the display region DR of the foldable display panel310aface each other when folded. In another example, as illustrated inFIG.5B, the flexible display device300may be an out-foldable display device300bincluding the foldable display panel310bthat is folded at the fixed bendable position BPb such that a portion of the display region DR is located at a front side (e.g., facing a viewer) and another portion of the display region DR is located at a back side (e.g., facing away from the viewer) when folded. AlthoughFIGS.5A and5Billustrate examples where the flexible display device300is the foldable display device300aand300b, the flexible display device300may be any flexible display device, such as a rollable display device, a curved display device, a bended display device, a stretchable display device, or the like.

Referring again toFIG.4, the flexible display panel310may further include an outer measuring line OML surrounding the display region DR of the flexible display panel310. The display driver330may apply a current IL to a first end of the outer measuring line OML, and may sense a resistance of the outer measuring line OML by measuring a voltage VM of a second end of the outer measuring line OML. Based on the sensed resistance of the outer measuring line OML, the display driver330may determine where the flexible display panel310is deformed, and may determine a deformation amount of the flexible display panel310.

For example, as illustrated inFIG.6, in a case where a resistance340of the outer measuring line OML is less than (or equal to) a reference resistance REFR, the display driver330may determine that the flexible display panel310is not deformed. Alternatively, in a case where a resistance350of the outer measuring line OML is greater than the reference resistance REFR, the display driver330may determine that the flexible display panel310is deformed, for example that the flexible display panel310is folded or bent. Further, the display driver330may determine the deformation amount of the flexible display panel310corresponding to the resistance350of the outer measuring line OML. For example, the display driver330may store resistance-deformation amount model information about a deformation amount value of the flexible display panel310corresponding to a resistance value of the outer measuring line OML, and may determine the deformation amount of the flexible display panel310corresponding to the resistance350of the outer measuring line OML by using the resistance-deformation amount model information.

In some embodiments, the flexible display device300according to embodiments may compensate or increase the power supply voltage ELVDD supplied to the flexible display panel310based on the resistance350of the outer measuring line OML. For example, the display driver330may store resistance-voltage drop model information about a voltage drop amount of the power supply voltage ELVDD at the power supply line ELVDDL corresponding to the resistance value of the outer measuring line OML, may determine the voltage drop amount of the power supply voltage ELVDD corresponding to the resistance350of the outer measuring line OML by using the resistance-voltage drop model information, and may increase a voltage level of the power supply voltage ELVDD by the determined voltage drop amount. Accordingly, even if the flexible display panel310is deformed, deterioration of an image quality of the flexible display panel310may be prevented or reduced.

FIG.7is a diagram illustrating a flexible display device having one fixed bendable position according to embodiments,FIG.8Ais a diagram illustrating an example of resistances of first and second measuring lines in a case where a flexible display panel is not bent, andFIG.8Bis a diagram illustrating an example of resistances of first and second measuring lines in a case where a flexible display panel is bent.

Referring toFIG.7, a flexible display device400according to embodiments may include a flexible display panel410, a power management circuit420and a display driver430. The flexible display device400ofFIG.7may have a similar configuration and a similar operation to a flexible display device300ofFIG.4, except that the flexible display panel410may include first and second measuring lines ML1and ML2instead of an outer measuring line OML.

The flexible display panel410may be a foldable display panel having a fixed bendable position BP, and may include a first measuring line ML1extending from the display driver430to a first position P1, and a second measuring line ML2extending from the display driver430to a second position P2. The first position P1and the second position P2are located in the flexible display panel410. The first position P1may be closer to the display driver430than the bendable position BP, and the second position P2may be farther from the display driver430than the bendable position BP. For example, as illustrated inFIG.7, the first measuring line ML1may include a first portion MLP1extending from the display driver430to the first position P1and a second portion MLP2extending from the first position P1to the display driver430, and the second measuring line ML2may include a third portion MLP3extending from the display driver430to the second position P2and a fourth portion MLP4extending from the second position P2to the display driver430.

The display driver430may sense a resistance of the first measuring line ML1and a resistance of the second measuring line ML2. For example, the display driver430may sense the resistance of the first measuring line ML1by applying a current to one end of the first measuring line ML1and by measuring a voltage of the other end of the first measuring line ML1, and may sense the resistance of the second measuring line ML2by applying a current to one end of the second measuring line ML2and by measuring a voltage of the other end of the second measuring line ML2. Based on a difference between the resistance of the first measuring line ML1and the resistance of the second measuring line ML2, the display driver430may determine where the flexible display panel410is deformed, and may determine a deformation amount of the flexible display panel410.

For example, as illustrated inFIG.8A, in a case where a difference RD between a resistance450aof the first measuring line ML1corresponding to the first position P1and a resistance460aof the second measuring line ML2corresponding to the second position P2is less than (or equal to) a reference resistance REFR, the display driver430may determine that the flexible display panel410is not deformed. Alternatively, in a case where a difference RD between a resistance450bof the first measuring line ML1corresponding to the first position P1and a resistance460bof the second measuring line ML2corresponding to the second position P2is greater than the reference resistance REFR, the display driver430may determine that the flexible display panel410is deformed, for example that the flexible display panel410is folded or bent. Further, the display driver430may determine the deformation amount of the flexible display panel410corresponding to the difference RD between the resistances450band460bof the first and second measuring lines ML1and ML2. For example, the display driver430may store resistance-deformation amount model information about a deformation amount value of the flexible display panel410corresponding to a resistance difference value of the first and second measuring lines ML1and ML2, and may determine the deformation amount of the flexible display panel410corresponding to the difference RD between the resistances450band460bof the first and second measuring lines ML1and ML2by using the resistance-deformation amount model information.

In some embodiments, the flexible display device400according to embodiments may compensate or increase a power supply voltage ELVDD supplied to the flexible display panel410based on the difference RD between the resistances450band460bof the first and second measuring lines ML1and ML2. For example, the display driver430may store resistance-voltage drop model information about a voltage drop amount of the power supply voltage ELVDD at a power supply line ELVDDL corresponding to the resistance difference value of the first and second measuring lines ML1and ML2, may determine the voltage drop amount of the power supply voltage ELVDD corresponding to the difference RD between the resistances450band460bof the first and second measuring lines ML1and ML2by using the resistance-voltage drop model information, and may increase a voltage level of the power supply voltage ELVDD by the determined voltage drop amount. Accordingly, even if the flexible display panel410is deformed, deterioration of an image quality of the flexible display panel410may be prevented or reduced.

FIG.9is a diagram illustrating a flexible display device having two fixed bendable positions according to embodiments,FIG.10is a diagram illustrating an example of a flexible display device according to embodiments,FIG.11Ais a diagram illustrating an example of resistances of first through third measuring lines in a case where a flexible display panel is not bent,FIG.11Bis a diagram illustrating an example of resistances of first through third measuring lines in a case where a flexible display panel is bent at a first bendable position,FIG.11Cis a diagram illustrating an example of resistances of first through third measuring lines in a case where a flexible display panel is bent at a second bendable position, andFIG.11Dis a diagram illustrating an example of resistances of first through third measuring lines in a case where a flexible display panel is bent at first and second bendable positions.

Referring toFIG.9, a flexible display device500according to embodiments may include a flexible display panel510, a power management circuit520and a display driver530. The flexible display device500ofFIG.9may have a similar configuration and a similar operation to a flexible display device300ofFIG.4or a flexible display device400ofFIG.7, except that the flexible display panel510may have two fixed bendable positions BP1and BP2, and may include first, second and third measuring lines ML1, ML2and ML3extending to first, second and third positions P1, P2and P3, respectively. The first, second and third positions P1, P2and P3are located in the flexible display panel510.

Unlike a flexible display panel310ofFIG.4or a flexible display panel410ofFIG.7having one fixed bendable position BP, the flexible display panel510may be a foldable display panel having two fixed bendable positions BP1and BP2. For example, as illustrated inFIG.10, the flexible display device500may be a foldable display device including the flexible display panel510that is bent or folded at each of a first bendable position BP1and a second bendable position BP2.

The flexible display panel510may include a first measuring line ML1extending from the display driver530to a first position P1, a second measuring line ML2extending from the display driver530to a second position P2and a third measuring line ML3extending from the display driver530to a third position P3. The first position P1may be closer to the display driver530than the first bendable position BP1, the second position P2may be farther from the display driver530than the first bendable position BP1and closer to the display driver530than the second bendable position BP2, and the third position P3may be farther from the display driver530than the second bendable position BP2.

The display driver530may sense a resistance of the first measuring line ML1, a resistance of the second measuring line ML2and a resistance of the third measuring line ML3. Further, the display driver530may detect a deformation position and a deformation amount of the flexible display panel510based on differences of the resistances of the first, second and third measuring lines ML1, ML2and ML3. In some embodiments, based on the difference between the resistance of the first measuring line ML1and the resistance of the second measuring line ML2, the display driver530may determine where the flexible display panel510is deformed at the first bendable position BP1, and may determine the deformation amount of the flexible display panel510at the first bendable position BP1. Further, based on the difference between the resistance of the second measuring line ML2and the resistance of the third measuring line ML3, the display driver530may determine where the flexible display panel510is deformed at the second bendable position BP2, and may determine the deformation amount of the flexible display panel510at the second bendable position BP2.

For example, as illustrated inFIG.11A, in a case where each of a first difference RD1between resistances550aand560aof the first and second measuring lines ML1and ML2and a second difference RD2between resistances560aand570aof the second and third measuring lines ML2and ML3is less than (or equal to) a reference resistance REFR, the display driver530may determine that the flexible display panel510is not deformed (e.g., neither folded nor bent). In another example, as illustrated inFIG.11B, in a case where a first difference RD1between resistances550band560bof the first and second measuring lines ML1and ML2is greater than the reference resistance REFR, and a second difference RD2between resistances560band570bof the second and third measuring lines ML2and ML3is less than (or equal to) the reference resistance REFR, the display driver530may determine that the flexible display panel510is deformed (e.g., folded or bent) at the first bendable position BP1. In still another example, as illustrated inFIG.11C, in a case where a first difference RD1between resistances550cand560cof the first and second measuring lines ML1and ML2is less than (or equal to) the reference resistance REFR, and a second difference RD2between resistances560cand570cof the second and third measuring lines ML2and ML3is greater than the reference resistance REFR, the display driver530may determine that the flexible display panel510is deformed at the second bendable position BP2. In still another example, as illustrated inFIG.11D, in a case where a first difference RD1between resistances550dand560dof the first and second measuring lines ML1and ML2is greater than the reference resistance REFR, and a second difference RD2between resistances560dand570dof the second and third measuring lines ML2and ML3is greater than the reference resistance REFR, the display driver530may determine that the flexible display panel510is deformed (e.g., folded or bent) at both of the first bendable position BP1and the second bendable position BP2.

Further, the display driver530may determine the deformation amount at the first bendable position BP1corresponding to the first difference RD1between the resistances550dand560dof the first and second measuring lines ML1and ML2, and may determine the deformation amount at the second bendable position BP2corresponding to the second difference RD2between resistances560dand570dof the second and third measuring lines ML2and ML3. For example, the display driver530may store resistance-deformation amount model information about a deformation amount value corresponding to each resistance difference value, and may determine the deformation amount at the first bendable position BP1corresponding to the first difference RD1and the deformation amount at the second bendable position BP2corresponding to the second difference RD2by using the resistance-deformation amount model information.

In some embodiments, the flexible display device500may compensate or increase a power supply voltage ELVDD supplied to the flexible display panel510based on the differences RD1and RD2between the resistances550d,560dand570dof the first, second and third measuring lines ML1, ML2and ML3. Further, in some embodiments, the flexible display device500may compensate or increase the power supply voltage ELVDD based on a greater one of the differences RD1and RD2between the resistances550d,560dand570d. For example, the display driver530may store resistance-voltage drop model information about a voltage drop amount of the power supply voltage ELVDD corresponding to each resistance difference value, may determine the voltage drop amount of the power supply voltage ELVDD corresponding to the second difference RD2between the resistances560dand570dof the second and third measuring lines ML2and ML3by using the resistance-voltage drop model information in a case where the second difference RD2between the resistances560dand570dof the second and third measuring lines ML2and ML3is greater than the first difference RD1between the resistances550dand560dof the first and second measuring lines ML1and ML2, and may increase a voltage level of the power supply voltage ELVDD by the determined voltage drop amount. Accordingly, even if the flexible display panel510is deformed, deterioration of an image quality of the flexible display panel510may be prevented or reduced.

FIG.12is a diagram illustrating a flexible display device including a foldable display panel that is able to be bent at any position according to embodiments, andFIG.13is a diagram illustrating an example of resistances of a plurality of measuring lines in a case where a flexible display panel is bent.

Referring toFIG.12, a flexible display device600according to embodiments may include a flexible display panel610, a power management circuit620and a display driver630. The flexible display device600ofFIG.12may have a similar configuration and a similar operation to a flexible display device300,400or500ofFIG.4,FIG.7orFIG.9, except that the flexible display panel610is able to be bent or folded at any position, and may include a plurality of measuring lines ML1, ML2, ML3, . . . , MLN−1 and MLN extending to a plurality of positions P1, P2, P3, . . . , PN−1 and PN, respectively. The plurality of positions P1, P2, P3, . . . , PN−1 and PN is located in the flexible display panel610.

Unlike a flexible display panel310,410or510ofFIG.4,FIG.7orFIG.9having one or more fixed bendable positions, the flexible display panel610may be a foldable display panel that is able to be bent or folded at any position.

The flexible display panel610may include first through N-th measuring lines ML1through MLN extending from the display driver630to first through N-th positions P1through PN, where N is an integer greater than 1. For example, the first through N-th positions P1through PN may have, but not limited to, a regular interval.

The display driver630may sense resistances of the first through N-th measuring lines ML1through MLN. Further, the display driver630may detect a deformation position and a deformation amount of the flexible display panel610based on differences of the resistances of the first through N-th measuring lines ML1through MLN. In some embodiments, in a case where a difference between the resistances of two measuring lines extending to adjacent two positions among the first through N-th measuring lines ML1through MLN is greater than a reference resistance, the display driver630may determine that the deformation position of the flexible display panel610is between the adjacent two positions. Further, in some embodiments, the display driver630may determine the deformation amount of the flexible display panel610at the deformation position based on the difference between the resistances of the two measuring lines.

For example, as illustrated inFIG.13, in a case where a first difference RD1between the resistance of the second measuring line ML2corresponding to the second position P2and the resistance of the third measuring line ML3corresponding to the third position P3is greater than the reference resistance REFR, and a second difference RD2between the resistance of the (N−1)-th measuring line MLN−1 corresponding to the (N−1)-th position PN−1 and the resistance of the N-th measuring line MLN corresponding to the N-th position PN is greater than the reference resistance REFR, the display driver630may determine that the flexible display panel610is deformed at a first deformation position (e.g., a first bendable position) between the second position P2and the third position P3, and that the flexible display panel610is further deformed at a second deformation position (e.g., a second bendable position) between the (N−1)-th position PN−1 and the N-th position PN.

In some embodiments, the flexible display device600may compensate or increase a power supply voltage ELVDD supplied to the flexible display panel610based on the differences of the resistances of the first through N-th measuring lines ML1through MLN. Further, in some embodiments, the flexible display device600may compensate or increase the power supply voltage ELVDD based on a greatest one of the differences of the resistances. For example, in a case where the second difference RD2between the resistances of the (N−1)-th and N-th measuring lines MLN−1 and MLN is greatest, the display driver630may determine a voltage drop amount of the power supply voltage ELVDD corresponding to the second difference RD2between the resistances of the (N−1)-th and N-th measuring lines MLN−1 and MLN, and may increase a voltage level of the power supply voltage ELVDD by the determined voltage drop amount. Accordingly, even if the flexible display panel610is deformed, deterioration of an image quality of the flexible display panel610may be prevented or reduced.

FIG.14is a block diagram illustrating a flexible display device according to embodiments,FIG.15Ais a diagram illustrating an example of a resistance-data compensation model, andFIG.15Bis a diagram illustrating another example of a resistance-data compensation model.

Referring toFIG.14, a flexible display device700according to embodiments may include a flexible display panel710, a power management circuit720and a display driver730. The display driver730may include a data driver740and a controller760. The controller760may include a resistance-deformation amount model storage770and a resistance-data compensation model storage780. Here, the resistance-deformation amount model storage170, the resistance-voltage drop model storage180, the resistance-deformation amount model storage770, and the resistance-data compensation model storage780may be implemented by a storage device such as memory. In some embodiments, the flexible display device700may further include a scan driver750. The flexible display device700of FIG.14may have a similar configuration and a similar operation to a flexible display device100ofFIG.1, except that the display driver730may include the resistance-data compensation model storage780, and may compensate input image data IDAT instead of or along with a power supply voltage ELVDD based on a resistance of at least one measuring line ML.

The resistance-data compensation model storage780may store resistance-data compensation model information about a data compensation value corresponding to a resistance value (or a resistance difference value) of the at least one measuring line ML. The display driver730may sense a resistance of the at least one measuring line ML, and may generate output image data ODAT by compensating the input image data IDAT based on the sensed resistance of the at least one measuring line ML and the resistance-data compensation model information stored in the resistance-data compensation model storage780. In some embodiments, the display driver730may determine the data compensation value corresponding to the sensed resistance of the at least one measuring line ML based on the resistance-data compensation model information, and may generate the output image data ODAT for each pixel PX by adding the data compensation value to a gray level represented by the input image data IDAT with respect to each pixel PX. The resistance-data compensation model information may be stored as various forms, for example, a lookup table or an equation.

In some embodiments, the resistance-data compensation model information stored in the resistance-data compensation model storage780may be determined through experiments for the flexible display device700. For example, as illustrated inFIG.15A, the resistance-data compensation model information stored in the resistance-data compensation model storage780may represent a linear relationship810between the resistance value (or the resistance difference value) greater than a reference resistance REFR and the data compensation value. In another example, as illustrated inFIG.15B, the resistance-data compensation model information stored in the resistance-data compensation model storage780may represent a nonlinear relationship820between the resistance value (or the resistance difference value) greater than the reference resistance REFR and the data compensation value. Further, in some embodiments, the resistance-data compensation model storage780may be implemented in a form of a lookup table that outputs a corresponding data compensation value in response to each resistance value (or each resistance difference value), but a configuration of the resistance-data compensation model storage780is not limited to the lookup table.

In the flexible display device700according to embodiments, the display driver730may sense the resistance of the at least one measuring line ML, and may detect at least one of a deformation position and a deformation amount of the flexible display panel710based on the sensed resistance of the at least one measuring line ML. Further, in the flexible display device700according to embodiments, the input image data IDAT may be compensated based on the deformation position and/or the deformation amount. Accordingly, even if the flexible display panel710is deformed, deterioration of luminance uniformity and color deviation of the flexible display panel710may be prevented or reduced.

FIG.16is a diagram for describing an example where input image data are compensated in a flexible display device having one fixed bendable position.

Referring toFIG.16, a flexible display panel310/410of a flexible display device300/400may have one fixed bendable position BP. For example, the flexible display device300/400may be a flexible display device300ofFIG.4or a flexible display device400ofFIG.7. The flexible display panel310/410may include, as least one measuring line, an outer measuring line OML as illustrated inFIG.4, or first and second measuring lines ML1and ML2corresponding to first and second positions P1and P2as illustrated inFIG.7.

If the flexible display panel310/410is deformed (e.g., bent or folded) at the bendable position BP, a power supply voltage ELVDD may be decreased by a voltage drop VD at the bendable position BP and positions farther from the display driver330/430than the bendable position BP as illustrated as a graph830. However, the flexible display device300/400may sense a resistance of the as least one measuring line, and may generate output image data ODAT by increasing input image data IDAT for a plurality of pixels located farther from the display driver330/430than the bendable position BP (e.g., for a plurality of pixels located at a lower portion below the bendable position BP) by a data compensation value DCV based on the resistance of the as least one measuring line as illustrated as a graph840. Accordingly, even if the flexible display panel310/410is deformed, deterioration of an image quality of the flexible display panel310/410may be effectively prevented or reduced.

FIG.17is a diagram for describing an example where input image data are compensated in a flexible display device having two fixed bendable positions.

Referring toFIG.17, a flexible display panel510of a flexible display device500may have two fixed bendable position BP1and BP2. The flexible display panel510may include, as least one measuring line, first, second and third measuring lines ML1, ML2and ML3corresponding to first, second and third positions P1, P2and P3as illustrated inFIG.9.

If the flexible display panel510is deformed (e.g., bent or folded) at the first and second bendable positions BP1and BP2, a power supply voltage ELVDD may be decreased by first and second voltage drops VD1and VD2at the first and second bendable positions BP1and BP2as illustrated as a graph850. However, the flexible display device500may sense a resistance of the as least one measuring line, and may generate output image data ODAT by increasing input image data IDAT for a plurality of pixels located farther from the display driver330/430than the first bendable position BP1(e.g., for a plurality of pixels located at a lower portion below the first bendable position BP1) by a first data compensation value DCV1and by further increasing the input image data IDAT for a plurality of pixels located farther from the display driver330/430than the second bendable position BP2(e.g., for a plurality of pixels located at a lower portion below the second bendable position BP2) by a second data compensation value DCV2based on the resistance of the as least one measuring line as illustrated as a graph860. Accordingly, even if the flexible display panel510is deformed, deterioration of an image quality of the flexible display panel510may be effectively prevented or reduced.

FIG.18is a diagram for describing an example where input image data are compensated in a flexible display device including a foldable display panel that is able to be bent at any position.

Referring toFIG.18, a flexible display panel610of a flexible display device600may be deformed (e.g., bent or folded) at any position. The flexible display panel610may include, as least one measuring line, first through N-th measuring lines ML1through MLN corresponding to first through N-th positions P1through PN as illustrated inFIG.12.

If the flexible display panel610is deformed (e.g., bent or folded) at first and second bendable positions BP1and BP2that are not fixed (not predetermined), for example, the flexible display device600may determine that the first bendable position BP1is between the second position P2and the third position P3and that the second bendable position BP2is between the (N−1)-th position PN−1 and the N-th position PN by sensing resistances of the first through N-th measuring lines ML1through MLN Further, if the flexible display panel610is deformed at the first and second bendable positions BP1and BP2, a power supply voltage ELVDD may be decreased by first and second voltage drops VD1and VD2at the first and second bendable positions BP1and BP2as illustrated as a graph870. However, as illustrated as a graph880, the flexible display device600may generate output image data ODAT by gradually increasing input image data IDAT by up to a first data compensation value DCV1between the second position P2and the third position P3, by keeping the first data compensation value DCV1between the third position P3and the (N−1)-th position PN−1 and by further gradually increasing the input image data IDAT by up to a second data compensation value DCV2between the (N−1)-th position PN−1 and the N-th position PN. Accordingly, even if the flexible display panel610is deformed, deterioration of an image quality of the flexible display panel610may be effectively prevented or reduced.

FIG.19is a block diagram illustrating an electronic device including a flexible display device according to embodiments, andFIG.20is a diagram for describing an example where a region displaying a moving image is changed in a case where a flexible display panel is deformed.

Referring toFIG.19, an electronic device900according to embodiments may include a host processor910and a flexible display device920. In some embodiments, the electronic device900may further include a memory device, a storage device, an input/output device, a power supply, etc.

The host processor910may control an overall operation of the electronic device900. According to embodiments, the host processor910may be an application processor (AP) including a graphics processing unit (GPU), a microprocessor, a central processing unit (“CPU”), etc. The host processor910may generate input image data IDAT and a control signal CTRL, and may provide the input image data IDAT and the control signal CTRL to the flexible display device920. Further, the host processor910may receive deformation information DI representing a deformation position and/or a deformation amount of a flexible display panel930from the flexible display device920.

The flexible display device920may display an image based on the input image data IDAT. The flexible display device920may include the flexible display panel930including a plurality of pixels, and a display driver940that drives the flexible display panel930. The flexible display panel930may further include at least one measuring line. The display driver940may sense a resistance of the at least one measuring line, and may detect at least one of the deformation position and the deformation amount of the flexible display panel930based on the sensed resistance. The display driver940may provide the deformation information DI representing at least one of the deformation position and the deformation amount to the host processor910.

In some embodiments, the host processor910may control a user interface based on the deformation information DI. For example, as illustrated inFIG.20, in a case where, while the flexible display panel930displays a moving image or a video, the host processor910receives the deformation information DI indicating that the flexible display panel930is deformed, the host processor910may adjust the input image data IDAT in response to the deformation information DI such that a region of the flexible display panel930displaying the moving image is changed. For example, in a case where the flexible display panel930is deformed while the moving image is displayed at the entire display region of the flexible display panel930, the host processor910may adjust the input image data IDAT such that the moving image is displayed at a first area932of the display region of the flexible display panel930. Further, in some embodiments, the host processor910may adjust the input image data IDAT such that no image is displayed at a second area934of the display region of the flexible display panel930, or such that a user interface image (e.g., a keyboard image or information image) is displayed at the second area934of the display region of the flexible display panel930.

The inventive concepts may be applied to any electronic device900including the flexible display device920, such as a mobile phone, a smart phone, a tablet computer, a television (“TV”), a digital TV, a 3D TV, a wearable electronic device, 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, a navigation device, etc.