Organic light emitting diode display device and method of operating the same

Abstract

An organic light emitting diode (OLED) display device and a method for operating the same are provided. The OLED display device includes a display panel having a plurality of pixel rows and a panel driver for driving the display panel. The panel driver includes: a determination circuit that selects a pixel row from the plurality of pixel rows, determines load data based on input image data of the pixel row, and determines target mobility data corresponding to the load data; a sensing circuit that generates mobility sensing data corresponding to mobility values of drive transistors of a plurality of pixels included in the pixel row by performing a mobility sensing operation on the pixel row; and a current control circuit that compares the mobility sensing data with the target mobility data to generate a result, and adjusts a panel current flowing through the display panel according to the result.

Description

Technical Field

[0001] Exemplary embodiments of the present inventive concept relate to a display device, and more particularly, to an organic light emitting diode (OLED) display device and a method of operating the OLED display device. Background Art

[0002] A display device such as an organic light emitting diode (OLED) display device includes a display panel having a plurality of pixels for displaying an image. The current flowing in the pixels during operation of the OLED display device may be referred to as a panel current. If the panel current is controlled to not exceed a predetermined maximum current, power consumption may be reduced. Control of the panel current includes sensing the value of the panel current. For example, the panel current may be sensed by using a series resistor connected in series with the display panel. However, because a series resistor having a very large resistance value is required to sense the panel current, the cost and power consumption of the OLED display device are substantially increased due to the series resistor. Summary of the Invention

[0003] At least one disclosed exemplary embodiment provides an organic light emitting diode (OLED) display device capable of controlling a panel current without requiring a series resistor for sensing the panel current.

[0004] At least one disclosed exemplary embodiment provides a method of operating an OLED display device capable of controlling a panel current without requiring a series resistor for sensing the panel current.

[0005] According to a disclosed exemplary embodiment, an OLED display device having a display panel and a panel driver is provided, the display panel including a plurality of pixel rows, and the panel driver configured to drive the display panel. The panel driver includes: a determination circuit configured to select a pixel row from the plurality of pixel rows, determine load data based on input image data of the pixel row, and determine target mobility data corresponding to the load data; a sensing circuit configured to generate mobility sensing data by performing a mobility sensing operation on the pixel row, the mobility sensing data corresponding to mobility values of drive transistors of a plurality of pixels included in the pixel row; and a current control circuit configured to compare the mobility sensing data with the target mobility data to generate a result, and adjust a panel current flowing through the display panel according to the result.

[0006] In an exemplary embodiment, the determination circuit calculates a plurality of pixel row load data of the plurality of pixel rows based on input image data of the plurality of pixel rows, and selects the one pixel row having the maximum pixel row load data among the plurality of pixel row load data of the plurality of pixel rows.

[0007] In an exemplary embodiment, the selected one pixel row is an uppermost pixel row or a lowermost pixel row among the plurality of pixel rows.

[0008] In an exemplary embodiment, the determination circuit sequentially selects the plurality of pixel rows such that selection of the one pixel row is changed every frame period.

[0009] In an exemplary embodiment, the determination circuit calculates the load data by dividing the input image data of the one pixel row by the maximum image data of the one pixel row.

[0010] In an exemplary embodiment, when the load data is greater than or equal to the reference load data, the determination circuit determines the target mobility data as maximum target mobility data corresponding to the reference load data.

[0011] In an exemplary embodiment, the determination circuit includes a memory device configured to store a plurality of target mobility values respectively corresponding to a plurality of load values, and determines the target mobility data corresponding to the load data by using the memory device.

[0012] In an exemplary embodiment, the determination circuit determines two load values adjacent to the load value represented by the load data among the multiple load values, obtains two target mobility values corresponding to the two load values among the multiple target mobility values from the memory device, and interpolates the target mobility data from the two target mobility values.

[0013] In an exemplary embodiment, the plurality of target mobility values stored in the memory device are measured by using a sensing circuit before performing an aging process of the display panel.

[0014] In an exemplary embodiment, in a sensing period of each frame period, the panel driver applies a reference voltage to a plurality of pixels included in the one pixel row, senses a sensing voltage change of a plurality of sensing lines coupled to the plurality of pixels during a sensing time within the sensing period by using a sensing circuit, and generates mobility sensing data based on the sensing voltage change.

[0015] In an exemplary embodiment, the current control circuit reduces the panel current when the mobility sensing data is greater than the target mobility data, and increases the panel current when the mobility sensing data is less than the target mobility data.

[0016] In an exemplary embodiment, when the mobility sensing data is greater than the target mobility data, the current control circuit generates output image data provided to a data driver included in the panel driver by reducing input image data of the plurality of pixel rows, thereby reducing data voltages applied to the plurality of pixel rows. When the mobility sensing data is less than the target mobility data, the current control circuit generates output image data provided to the data driver by increasing the input image data of the plurality of pixel rows, thereby increasing data voltages applied to the plurality of pixel rows.

[0017] In an exemplary embodiment, the panel driver further includes an overcurrent protection circuit configured to stop the operation of the OLED display device when the mobility sensing data is greater than the target mobility data by more than a shutdown reference amount during a plurality of frame periods corresponding to a shutdown reference time.

[0018] According to a disclosed exemplary embodiment, a method for operating an OLED display device is provided, the OLED display device including a display panel having a plurality of pixel rows. In the method, a pixel row is selected from the plurality of pixel rows; load data is determined based on input image data of the pixel row; target mobility data corresponding to the load data is determined; mobility sensing data is generated by performing a mobility sensing operation on the pixel row, the mobility sensing data corresponding to mobility values of drive transistors of a plurality of pixels included in the pixel row; the mobility sensing data is compared with the target mobility data to generate a result; and a panel current flowing through the display panel is adjusted according to the result.

[0019] In an exemplary embodiment, in order to select the one pixel row, multiple pixel row load data of the multiple pixel rows are calculated based on the input image data of the multiple pixel rows, and the one pixel row having the maximum pixel row load data among the multiple pixel row load data of the multiple pixel rows is selected.

[0020] In an exemplary embodiment, in order to select the one pixel row, an uppermost pixel row or a lowermost pixel row among the plurality of pixel rows is selected.

[0021] In an exemplary embodiment, in order to select the one pixel row, the plurality of pixel rows are sequentially selected such that the selection of the one pixel row is changed every frame period.

[0022] In an exemplary embodiment, to adjust the panel current, the panel current is reduced when the mobility sensing data is greater than the target mobility data, and is increased when the mobility sensing data is less than the target mobility data.

[0023] In an exemplary embodiment, in order to reduce the panel current, the data voltage applied to the plurality of pixel rows is reduced. In order to increase the panel current, the data voltage applied to the plurality of pixel rows is increased.

[0024] In an exemplary embodiment, when the mobility sensing data is greater than the target mobility data by more than the off reference amount during a plurality of frame periods corresponding to the off reference time, the operation of the OLED display device is stopped.

[0025] According to an exemplary embodiment of the disclosure, an organic light emitting diode (OLED) display device including a display panel and a panel driver is provided. The display panel includes a plurality of pixel rows, a plurality of data lines, and a plurality of sensing lines. Each pixel row includes a plurality of pixels, each pixel being connected to a corresponding data line in the plurality of data lines and a corresponding sensing line in the plurality of sensing lines. The panel driver is configured to drive the display panel. The panel driver is configured to output a data voltage to the plurality of data lines during an effective period of a frame period, and to sense a sensing voltage from the plurality of sensing lines during a sensing period of the frame period. The panel driver is configured to determine a sensing voltage change from a sensing voltage received from one of the plurality of pixel rows, determine mobility data from the sensing voltage change, compare the mobility data with a target value to generate a result, and adjust the panel current of the display panel based on the result.

[0026] In an embodiment, the panel driver includes a current control circuit configured to stop operation of the OLED display device when the mobility data exceeds a target value by more than a reference amount for more than N frame periods, where N is at least 1.

[0027] In an embodiment, when the mobility data exceeds a target value and the temperature of the display panel is greater than a threshold value, the panel driver increases the panel current.

[0028] As described above, in an OLED display device and a method of operating an OLED display device according to at least one disclosed exemplary embodiment, a pixel row is selected from a plurality of pixel rows, load data is determined based on input image data for the selected pixel row, target mobility data corresponding to the load data is determined, a mobility sensing operation is performed on the pixel row to generate mobility sensing data, and the panel current is adjusted by comparing the mobility sensing data with the target mobility data. Therefore, the OLED display device can control the panel current by using the mobility sensing data without requiring a series resistor for sensing the panel current, thereby reducing the cost and power consumption of the OLED display device.

[0029] Furthermore, in the OLED display device and the method of operating the OLED display device according to at least one disclosed exemplary embodiment, an overcurrent protection operation may be performed using mobility sensing data. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The disclosed exemplary embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.

[0031] Figure 1 is a block diagram illustrating an organic light emitting diode (OLED) display device according to a disclosed exemplary embodiment.

[0032] Figure 2 is a diagram showing an example of target mobility data according to load data.

[0033] Figure 3 is a diagram for describing an example of a target mobility storage block.

[0034] Figure 4 is a diagram illustrating a data driver and a display panel for describing an example of a mobility sensing operation.

[0035] Figure 5 is a timing chart for describing an example of a mobility sensing operation.

[0036] Figure 6 is a graph showing an example of the mobility of a drive transistor according to temperature.

[0037] Figure 7 is a flowchart illustrating a method of operating an OLED display device according to a disclosed exemplary embodiment.

[0038] Figure 8 Is used to describe Figure 7 FIG. 1 is a diagram of an example of selecting one pixel row on which a mobility sensing operation is performed in a method of FIG.

[0039] Figure 9 is a flowchart illustrating a method of operating an OLED display device according to a disclosed exemplary embodiment.

[0040] Figure 10 Is used to describe Figure 9 FIG. 1 is a diagram of an example of selecting one pixel row on which a mobility sensing operation is performed in a method of FIG.

[0041] Figure 11 is a flowchart illustrating a method of operating an OLED display device according to a disclosed exemplary embodiment.

[0042] Figure 12 Is used to describe Figure 11FIG. 1 is a diagram of an example of selecting one pixel row on which a mobility sensing operation is performed in a method of FIG.

[0043] Figure 13 is a flowchart illustrating a method of operating an OLED display device according to a disclosed exemplary embodiment.

[0044] Figure 14 is a block diagram illustrating an electronic device including an OLED display device according to a disclosed exemplary embodiment. DETAILED DESCRIPTION

[0045] Hereinafter, exemplary embodiments of the present inventive concept will be explained in detail with reference to the accompanying drawings.

[0046] Figure 1 is a block diagram illustrating an organic light emitting diode (OLED) display device according to an exemplary embodiment of the disclosure, Figure 2 is a diagram showing an example of target mobility data according to load data, Figure 3 is a diagram for describing an example of a target mobility storage block (eg, a memory device), Figure 4 is a diagram showing a data driver and a display panel for describing an example of a mobility sensing operation, Figure 5 is a timing chart for describing an example of a mobility sensing operation, Figure 6 is a graph showing an example of the mobility of a drive transistor according to temperature.

[0047] Reference Figure 1 The OLED display device 100 according to the disclosed exemplary embodiment includes a display panel 110 including a plurality of pixel rows (e.g., PXR1, PXR2, . . . , PXRN) and a panel driver 120 (e.g., a driver circuit) that drives the display panel 110. In the exemplary embodiment, the panel driver 120 includes a scan driver 130 (e.g., a driver circuit) that provides a first scan signal SS1 and a second scan signal SS2 to the plurality of pixel rows, a data driver 140 (e.g., a driver circuit) that provides a data voltage DV to the plurality of pixel rows, a sensing circuit 160 that senses driving characteristics of driving transistors of the plurality of pixel rows, and a controller 170 (e.g., a control circuit) that controls the operation of the OLED display device 100.

[0048] The display panel 110 includes a plurality of pixel rows PXR1, PXR2, ..., PXRN, each including a plurality of pixels PX. In an exemplary embodiment, each pixel PX in a given pixel row receives the same first scan signal SS1 and the same second scan signal SS2. In an embodiment, the display panel 110 further includes a plurality of first scan lines (or gate lines) for transmitting the first scan signal SS1, a plurality of second scan lines for transmitting the second scan signal SS2, a plurality of data lines DL, and a plurality of sense lines SL. In an exemplary embodiment, each pixel PX includes an organic light emitting diode (OLED), and the display panel 110 is an OLED panel.

[0049] For example, Figure 4 As shown in FIG, each pixel PX includes a storage capacitor CST, a first switching transistor ST1, a second switching transistor ST2, a driving transistor DT, and an organic light-emitting diode EL. The first switching transistor ST1 couples the data line DL to the first electrode of the storage capacitor CST in response to a first scan signal SS1, and the second switching transistor ST2 couples the sensing line SL to the second electrode of the storage capacitor CST in response to a second scan signal SS2. The storage capacitor CST can store a data voltage DV transmitted via the data line DL. The driving transistor DT generates a driving current based on the data voltage DV stored in the storage capacitor CST. The organic light-emitting diode EL emits light based on the driving current generated by the driving transistor DT. Figure 4 FIG. 1 shows a pixel PX of the OLED display device 100 according to an exemplary embodiment of the inventive concept. However, the pixel PX is not limited to Figure 4 For example, the pixel PX may include Figure 4 The transistors shown in FIG.

[0050] The scan driver 130 generates a first scan signal SS1 and a second scan signal SS2 based on a scan control signal SCTRL received from the controller 170. The scan driver 130 may sequentially provide the first scan signal SS1 to a plurality of pixels PX on a pixel row basis, and may sequentially provide the second scan signal SS2 to a plurality of pixels PX on a pixel row basis. In some exemplary embodiments, the scan control signal SCTRL includes a scan start signal and a scan clock signal, but is not limited thereto. In some exemplary embodiments, the scan driver 130 may be integrated or formed in a peripheral area of the display panel 110. In other exemplary embodiments, the scan driver 130 may be implemented using one or more integrated circuits.

[0051] The data driver 140 generates a data voltage DV based on the output image data ODAT and the data control signal DCTRL received from the controller 170, and supplies the data voltage DV to the plurality of pixels PX. In some exemplary embodiments, the data control signal DCTRL includes a horizontal start signal and a load signal, but is not limited thereto. In exemplary embodiments, the data driver 140 includes an output buffer circuit 150 that outputs the data voltage DV to the data lines DL. In some exemplary embodiments, the output buffer circuit 150 sequentially supplies the data voltage DV to the plurality of pixel rows PXR1, PXR2, ..., PXRN via the data lines DL during an active period of a frame period, and supplies a reference voltage VREF for a mobility sensing operation to a selected pixel row among the plurality of pixel rows PXR1, PXR2, ..., PXRN via the data lines DL and the sense lines SL during a vertical blank period or a sensing period of the frame period. In some exemplary embodiments, the data driver 140 may be implemented using one or more integrated circuits. In other exemplary embodiments, the data driver 140 and the controller 170 may be implemented with a single integrated circuit, which may be referred to as a timing controller embedded data driver (TED).

[0052] The sensing circuit 160 receives a sensing voltage SV from a plurality of pixels PX through a plurality of sensing lines SL and generates sensing data corresponding to the sensing voltage SV. In some exemplary embodiments, the sensing data includes mobility sensing data MSD corresponding to the mobility values of the driving transistors DT of the plurality of pixels PX. In addition, in some exemplary embodiments, the sensing data also includes threshold voltage sensing data representing the threshold voltage values of the driving transistors DT of the plurality of pixels PX. For example, Figure 4 As shown in FIG, for each channel CH, the sensing circuit 160 includes a sensing capacitor SC coupled to the channel CH and an analog-to-digital converter ADC for converting a sensing voltage SV into sensing data. However, the sensing circuit 160 is not limited to Figure 4 In some exemplary embodiments, as described in Figure 1 As shown in FIG, the sensing circuit 160 is included in the data driver 140. However, the location of the sensing circuit 160 is not limited to Figure 1 For example, the sensing circuit 160 may be implemented with a separate integrated circuit, or may be included in the controller 170 .

[0053] The controller 170 (e.g., a timing controller (TCON)) receives input image data IDAT and a control signal CTRL. The input image data IDAT and the control signal CTRL may be received from an external host (e.g., a graphics processing unit (GPU), a graphics card, etc.). In some exemplary embodiments, the control signal CTRL includes a vertical synchronization signal, a horizontal synchronization signal, an input data enable signal, and a main clock signal, but is not limited thereto. The controller 170 generates output image data ODAT, a data control signal DCTRL, and a scan control signal SCTRL based on the input image data IDAT and the control signal CTRL. The controller 170 may control the operation of the data driver 140 by providing the output image data ODAT and the data control signal DCTRL to the data driver 140, and may control the operation of the scan driver 130 by providing the scan control signal SCTRL to the scan driver 130.

[0054] In the OLED display device 100 according to the disclosed exemplary embodiment, the panel driver 120 selects a pixel row from a plurality of pixel rows PXR1, PXR2, ..., PXRN, determines load data based on input image data IDAT of the selected pixel row, determines target mobility data TMD corresponding to the load data, generates mobility sensing data MSD by performing a mobility sensing operation on the selected pixel row, compares the mobility sensing data MSD with the target mobility data TMD, and adjusts the panel current flowing through the display panel 110 based on the comparison result. In the exemplary embodiment, the panel current is the sum of the driving currents flowing in the corresponding pixel PX due to the line receiving the first power supply voltage ELVDD and the line receiving the second power supply voltage ELVSS. However, the panel current is not limited to the sum and can be calculated in another manner. Therefore, in the OLED display device 100 according to the disclosed exemplary embodiment, the panel driver 120 controls the panel current by using the mobility sensing data MSD without requiring a series resistor for sensing the panel current. In the disclosed exemplary embodiments, the panel driver 120 further includes a target mobility determination block 180 (eg, a determination circuit) and a current control block 190 (eg, a current control circuit). In some exemplary embodiments, as Figure 1 As shown in FIG, the target mobility determination block 180 and the current control block 190 are included in the controller 170, but the locations of the target mobility determination block 180 and the current control block 190 are not limited to Figure 1 .

[0055] In an embodiment, the target mobility determination block 180 selects one pixel row on which a mobility sensing operation is to be performed from the plurality of pixel rows PXR1, PXR2, ..., PXRN. In some exemplary embodiments, as described below with reference to Figure 7 and Figure 8 As described above, the target mobility determination block 180 calculates a plurality of pixel row load data of the plurality of pixel rows PXR1, PXR2, ..., PXRN based on the input image data IDAT of the plurality of pixel rows PXR1, PXR2, ..., PXRN, and selects a pixel row having the maximum pixel row load data among the plurality of pixel row load data of the plurality of pixel rows PXR1, PXR2, ..., PXRN. In other exemplary embodiments, as described below with reference to Figure 9 and Figure 10 As described above, the target mobility determination block 180 selects the uppermost pixel row PXR1 or the lowermost pixel row PXRN among the plurality of pixel rows PXR1, PXR2, ..., PXRN. In other exemplary embodiments, as described below with reference to Figure 11 and Figure 12 As described above, the target mobility determination block 180 sequentially selects a plurality of pixel rows PXR1, PXR2, ..., PXRN so that the selection of one pixel row is changed every frame period. For example, the first pixel row PXR1 may be a pixel row selected during the first frame period, the second pixel row PXR2 may be a pixel row selected during the second frame period, and so on.

[0056] In an embodiment, the target mobility determination block 180 determines load data based on the input image data IDAT of the selected pixel row. In some exemplary embodiments, the target mobility determination block 180 calculates the load data by dividing the input image data IDAT of the selected pixel row by the maximum image data of the selected pixel row. For example, the load data can be calculated by dividing the average value or sum of the pixel data included in the input image data IDAT of the selected pixel row by the average value or sum of the pixel data included in the maximum image data. Here, the maximum image data may be row image data (or image data of the pixel row) including pixel data having a maximum grayscale level (e.g., grayscale level 255). For example, if all pixel data of the input image data IDAT of the selected pixel row represents the maximum grayscale level, the target mobility determination block 180 generates load data representing approximately 100% or exactly 100%. In another example, if all pixel data of the input image data IDAT of the selected pixel row represents an intermediate grayscale level (e.g., grayscale level 128), the target mobility determination block 180 generates load data representing approximately 50% or exactly 50%. In yet another example, when half of the pixel data of the input image data IDAT of the selected one pixel row represents the maximum grayscale level and the remaining half of the pixel data of the input image data IDAT of the selected one pixel row represents the minimum grayscale level (e.g., grayscale level 0), the target mobility determination block 180 generates load data representing approximately 50% or exactly 50%. In an exemplary embodiment, the grayscale levels of each pixel PX of a given pixel row are added together to generate a sum, the sum is divided by the number of pixels PX in the given pixel row to generate an average value, and the average value is divided by the maximum grayscale level to generate the load data for the given pixel row.

[0057] The target mobility determination block 180 determines target mobility data TMD corresponding to the load data. In some exemplary embodiments, as Figure 2 As shown in , when the load data is less than the reference load data RLD (for example, representing approximately 30%), the target mobility determination block 180 increases the target mobility data TMD as the load data increases. In an exemplary embodiment, when the load data is greater than or equal to the reference load data RLD, the target mobility determination block 180 sets the target mobility data TMD to the maximum target mobility data MTMD corresponding to the reference load data RLD. In this case, because the target mobility data TMD is limited to the maximum target mobility data MTMD, the panel current flowing through the display panel 110 is not excessively increased, and the power consumption of the OLED display device 100 can be reduced.

[0058] In some exemplary embodiments, Figure 1 and Figure 3 As shown in , the target mobility determination block 180 includes a target mobility storage block 185 (e.g., a memory device) that stores a plurality of target mobility values TMD1, TMD2, TMD3, TMD4, and TMD5, and the plurality of target mobility values TMD1, TMD2, TMD3, TMD4, and TMD5 correspond to a plurality of load values of, for example, approximately 1%, approximately 5%, approximately 10%, approximately 20%, and approximately 30%, respectively. The target mobility determination block 180 can determine the target mobility data TMD corresponding to the load data by using the target mobility storage block 185. For example, in the case where the load data represents a load value of approximately 10%, the target mobility determination block 180 can obtain a target mobility value TMD3 corresponding to a load value of approximately 10% from the target mobility storage block 185, and can generate target mobility data TMD having the target mobility value TMD3. In addition, in some exemplary embodiments, the target mobility determination block 180 determines two load values adjacent to the load value represented by the load data from among a plurality of load values, obtains two target mobility values corresponding to the two load values from among a plurality of target mobility values TMD1, TMD2, TMD3, TMD4, and TMD5 from the target mobility storage block 185, and interpolates target mobility data TMD from the two target mobility values. For example, in the case where the load data represents a load value of approximately 15%, the target mobility determination block 180 obtains two target mobility values TMD2 and TMD3 corresponding to two load values of approximately 10% and approximately 20% from the target mobility storage block 185, linearly interpolates interpolated target mobility values from the two target mobility values TMD2 and TMD3, and generates target mobility data TMD having the linearly interpolated target mobility values. In addition, in some exemplary embodiments, an aging process may be performed in which an aging signal (e.g., including scan signals SS1 and SS2 and a data voltage DV) is provided to the display panel 110 to enable the plurality of pixels PX to emit light, thereby improving the stability and reliability of the OLED display device 100 before the OLED display device 100 is sold. The plurality of target mobility values TMD1, TMD2, TMD3, TMD4, and TMD5 stored in the target mobility storage block 185 may be mobility values (e.g., an average value or a sum of the mobility values) of the drive transistors DT included in any one pixel row measured using the sensing circuit 160 before performing the aging process of the display panel 110. Therefore, the plurality of target mobility values TMD1, TMD2, TMD3, TMD4, and TMD5 stored in the target mobility storage block 185 may correspond to the initial mobility characteristics of the drive transistor DT, but are not limited thereto.

[0059] In an embodiment, the sensing circuit 160 generates mobility sensing data MSD corresponding to the mobility values (eg, the average value or the sum of the mobility values) of the driving transistors DT of the plurality of pixels PX included in the selected pixel row by performing a mobility sensing operation on the selected pixel row. Figure 4 and Figure 5 As shown in FIG, for each channel CH, the data driver 140 may further include a first switch SW1 for selectively coupling the output buffer circuit 150 to the channel CH, a second switch SW2 for selectively coupling the sensing circuit 160 to the channel CH, a third switch SW3 for selectively coupling the channel CH to the data line DL, a fourth switch SW4 for selectively coupling the channel CH to the sensing line SL, and a fifth switch SW5 for selectively coupling the sensing line SL to a line of a second reference voltage VREF2. In order to perform a mobility sensing operation for each pixel PX included in a selected pixel row, the data driver 140 may provide the first reference voltage VREF1 and the second reference voltage VREF2 to the first electrode and the second electrode of the storage capacitor CST, respectively, as reference voltages VREF, and may detect a change in the voltage V_SL of the sensing line SL or a change in the sensing voltage SV during a desired or predetermined sensing time ST by using the sensing circuit 160.

[0060] For example, Figure 5 As shown in , a mobility sensing operation for a selected pixel row can be performed during a sensing period SP of each frame period. In some exemplary embodiments, the sensing period SP of each frame period corresponds to a vertical blank period VBP between active periods. In an embodiment, the sensing period SP includes a first period P1, a second period P2, and a third period P3. A reference voltage VREF is applied to a plurality of pixels PX included in a selected pixel row during the first period P1. The plurality of pixels PX are coupled to the sensing circuit 160 via a plurality of sensing lines SL during the second period P2. The third period P3 includes a sensing time ST during which the mobility characteristics of the drive transistors DT of the plurality of pixels PX are sensed. In an embodiment, the third period P3 is longer than the first period P1 or the second period P2. In an embodiment, the third period P3 is longer than the sum of the first period P1 and the second period P2.

[0061] During the first period P1, the first switch SW1 is turned on, the second switch SW2 is turned off, the third switch SW3 is turned on, the fourth switch SW4 is turned off, and the fifth switch SW5 is turned on. Thus, each channel CH can be coupled to the output buffer circuit 150 and the data line DL, and the second reference voltage VREF2 can be applied to the sense line SL. Furthermore, a first scan signal SS1 having an on-level can be applied, and a second scan signal SS2 having an on-level can be applied, and the output buffer circuit 150 can output the first reference voltage VREF1 as the voltage DL_V of the data line DL. Consequently, the first switching transistor ST1 is turned on, and the first reference voltage VREF1 is applied to the first electrode of the storage capacitor CST. Furthermore, the second switching transistor ST2 is turned on, and the second reference voltage VREF2 is applied to the second electrode of the storage capacitor CST. Consequently, the storage capacitor CST stores the voltage difference between the first reference voltage VREF1 and the second reference voltage VREF2 as the reference voltage VREF.

[0062] In the second period P2, the first switch SW1 is turned off, the second switch SW2 is turned on, the third switch SW3 is turned off, the fourth switch SW4 is turned on, and the fifth switch SW5 remains in the on state. Therefore, each channel CH can be coupled to the sensing circuit 160 and the sensing line SL.

[0063] During the third period P3, the fifth switch SW5 is turned off. Therefore, the second reference voltage VREF2 is not applied to the sensing line SL, and based on the voltage difference between the first reference voltage VREF1 and the second reference voltage VREF2 stored in the storage capacitor CST, the voltage V_SL of the sensing line SL or the sensing voltage SV gradually increases from the initial voltage V0 to the second voltage V2 via the turned-on drive transistor DT. In an embodiment, the initial voltage V0 corresponds to the second reference voltage VREF2, which is a voltage lower than the first reference voltage VREF1. In an example, the first reference voltage VREF1 is approximately 5V, and the second reference voltage VREF2 is approximately 2V. However, the first reference voltage VREF1 and the second reference voltage VREF2 are not limited to these values. The sensing circuit 160 can detect changes in the voltage V_SL of the sensing line SL or the sensing voltage SV during the sensing time ST. For example, the sensing circuit 160 may measure a first voltage V1 as the voltage V_SL of the sensing line SL at a first time point T1, may measure a second voltage V2 as the voltage V_SL of the sensing line SL at a second time point T2 after a sensing time ST from the first time point T1, and may generate mobility sensing data MSD based on a change in the sensing voltage SV or a voltage difference between the first voltage V1 and the second voltage V2. In some exemplary embodiments, the sensing circuit 160 generates the mobility sensing data MSD by using the following equation 1: I=C×(V2-V1) / (T2-T1) (Equation 1).

[0064] In Equation 1, V1 is a first voltage, V2 is a second voltage, T1 is a first time point, T2 is a second time point, C is the capacitance of the sensing capacitor SC (and the parasitic capacitor of the sensing line SL), and I is the current of the sensing line SL. The current I of the sensing line SL may correspond to the mobility of the driving transistor DT. Therefore, the sensing circuit 160 may generate mobility sensing data MSD representing the current I of the sensing line SL calculated using the above Equation 1.

[0065] In an exemplary embodiment, in a sensing period SP of each frame period, the panel driver 120 applies a reference voltage VREF to a plurality of pixels PX included in one selected pixel row, detects a sensing voltage variation of a plurality of sensing lines SL coupled to the plurality of pixels PX during a sensing time ST within the sensing period SP by using the sensing circuit 160, and generates mobility sensing data MSD based on the sensing voltage variation. Figure 4 An example of each pixel PX of the display panel 110 and the data driver 140 performing a mobility sensing operation is shown, but the configuration of the data driver 140 and the pixel PX according to an exemplary embodiment is not limited to Figure 4 In addition, although Figure 5An example of a timing of switches, signals, and voltages for describing a mobility sensing operation is shown, but the mobility sensing operation of the OLED display device 100 according to an exemplary embodiment is not limited to Figure 5 .

[0066] Refer again Figure 1 The current control block 190 compares the mobility sensing data MSD with the target mobility data TMD and may adjust the panel current flowing through the display panel 110 based on the result of the comparison between the mobility sensing data MSD and the target mobility data TMD. In an exemplary embodiment, the current control block 190 reduces the panel current when the mobility sensing data MSD is greater than the target mobility data TMD, and increases the panel current when the mobility sensing data MSD is less than the target mobility data TMD. In some exemplary embodiments, when the mobility sensing data MSD is greater than the target mobility data TMD, the current control block 190 may generate the output image data ODAT provided to the data driver 140 by reducing the input image data IDAT of the plurality of pixel rows PXR1, PXR2, ..., PXRN, thereby reducing the data voltage DV applied to the plurality of pixel rows PXR1, PXR2, ..., PXRN. For example, the current control block 190 may generate the output image data ODAT by multiplying the pixel data included in the input image data IDAT by a coefficient less than 1. For example, the coefficient may be a value greater than 0 and less than 1. Therefore, the data voltage DV applied to the plurality of pixels PX can be reduced based on the output image data ODAT generated by reducing the input image data IDAT, and the driving current or panel current of the driving transistors DT of the plurality of pixels PX can be reduced based on the reduced data voltage DV. Furthermore, when the mobility sensing data MSD is less than the target mobility data TMD, the current control block 190 can generate the output image data ODAT provided to the data driver 140 by increasing the input image data IDAT of the plurality of pixel rows PXR1, PXR2, ..., PXRN, thereby increasing the data voltage DV applied to the plurality of pixel rows PXR1, PXR2, ..., PXRN. For example, the current control block 190 can generate the output image data ODAT by multiplying the pixel data included in the input image data IDAT by a coefficient greater than 1. Therefore, the data voltage DV applied to the plurality of pixels PX can be increased based on the output image data ODAT generated by increasing the input image data IDAT, and the driving current or panel current of the driving transistors DT of the plurality of pixels PX can be increased based on the increased data voltage DV.

[0067] If the temperature of the display panel 110 increases, the brightness or panel current of the display panel 110 may increase. In addition, if the brightness or panel current of the display panel 110 increases, the temperature of the display panel 110 may increase. Therefore, the brightness or panel current of the display panel 110 may be proportional to the temperature of the display panel 110. Figure 6 An example of the mobility (in logarithmic scale) of each driving transistor DT according to the temperature (in logarithmic scale) of the display panel 110 is shown. Figure 6 (For example, Figure 6 As shown in the left half of ), in the impurity scattering region 200 having a relatively low temperature, the mobility of the driving transistor DT increases as the temperature of the display panel 110 increases. Therefore, not only the panel current but also the mobility of the driving transistor DT can be proportional to the temperature of the display panel 110, and therefore, the mobility of the driving transistor DT can be proportional to the panel current and the panel temperature. Therefore, in the OLED display device 100 according to the disclosed exemplary embodiment, even if the current panel current is not directly sensed using a series resistor coupled to the display panel 110, the current panel current can be inferred from the mobility sensing data MSD representing the mobility of the driving transistor DT. In addition, in order to enable the mobility sensing data MSD corresponding to the current panel current to become the target mobility data TMD corresponding to the target panel current, the OLED display device 100 can adjust the panel current by adjusting the data voltage DV. Therefore, the OLED display device 100 can control the panel current to be substantially constant relative to substantially the same load data. Therefore, the OLED display device 100 can perform a constant current control operation without a series resistor. However, as Figure 6 (For example, Figure 6 As shown in the right half of FIG, in the lattice scattering region having a relatively high temperature, the mobility of the driving transistor DT decreases as the temperature of the display panel 110 increases. In the disclosed exemplary embodiment, when the driving transistor DT of the display panel 110 has the mobility characteristics in the lattice scattering region, the panel driver 120 increases the panel current when the mobility sensing data MSD is greater than the target mobility data TMD, and decreases the panel current when the mobility sensing data MSD is less than the target mobility data TMD.

[0068] A constant current control operation can be performed by sensing the current panel current using a series resistor coupled to the display panel 110. The panel current can be controlled by comparing the current panel current with a constant target panel current. However, in this case, a series resistor with a high resistance is required to sense the panel current, thereby increasing the cost of manufacturing the OLED display device. In addition, the power consumption of the OLED display device increases due to the series resistor. However, as described above, in the OLED display device 100 according to the disclosed exemplary embodiment, the panel current is controlled by using the mobility sensing data MSD, without the need for a series transistor for sensing the panel current, thereby reducing the cost and power consumption of the OLED display device 100.

[0069] In the disclosed exemplary embodiment, the panel driver 120 further includes an overcurrent protection circuit 195 for detecting overcurrent in the display panel 110 and for stopping the operation of the OLED display device 100. In an embodiment, when the mobility sensing data MSD exceeds the target mobility data TMD by more than a shutdown reference amount during a plurality of frame periods (e.g., 60 frame periods) corresponding to a shutdown reference time, the overcurrent protection circuit 195 determines that an overcurrent has occurred in the display panel 110 and stops the operation of the OLED display device 100. For example, if the overcurrent protection circuit 195 determines that the mobility sensing data MSD exceeds the target amount by more than a reference amount for a certain number of frame periods, the current control block 190, the controller 170, or the panel driver 120 may perform an operation to reduce the overcurrent. For example, the operation may include: the controller 170 no longer outputting the output image data ODAT; the controller 170 providing the scan control signal SCTRL, which notifies the scan driver 130 not to activate any scan signal; or the panel driver 120 blocking power to the data driver 140, the scan driver 130 and / or the display panel 110. In some exemplary embodiments, as Figure 1 As shown in FIG, the overcurrent protection circuit 195 may be included in the controller 170 or the current control block 190, but the location of the overcurrent protection circuit 195 is not limited to Figure 1 .

[0070] When a series resistor is included in an OLED display device, an overcurrent is determined to occur when the current panel current sensed using the series resistor is greater than a reference panel current that is constant and independent of the load data. However, when the series resistor is used when the load data indicates a low load, the overcurrent may not be detected. However, in the OLED display device 100 according to the disclosed exemplary embodiment, overcurrent is detected by using the mobility sensing data MSD and the target mobility data TMD corresponding to the load data. Therefore, even if the load data indicates a low load, the overcurrent can be accurately detected.

[0071] As described above, in the OLED display device 100 according to the disclosed exemplary embodiment, the panel driver 120 selects a pixel row from a plurality of pixel rows PXR1, PXR2, ..., PXRN, determines load data based on input image data IDAT of the selected pixel row, determines target mobility data TMD corresponding to the load data, generates mobility sensing data MSD by performing a mobility sensing operation on the selected pixel row, and adjusts the panel current by comparing the mobility sensing data MSD with the target mobility data TMD. Therefore, in the OLED display device 100 according to the disclosed exemplary embodiment, the panel driver 120 controls the panel current by using the mobility sensing data MSD without requiring a series resistor for sensing the panel current, thereby reducing the cost and power consumption of the OLED display device 100. Furthermore, in the OLED display device 100 according to the disclosed exemplary embodiment, the panel driver 120 performs an overcurrent protection operation using the mobility sensing data MSD. Therefore, in the OLED display device 100 according to the disclosed exemplary embodiment, the overcurrent protection operation can be normally performed even if the load data indicates a low load.

[0072] Figure 7 is a flowchart illustrating a method of operating an OLED display device according to a disclosed exemplary embodiment, Figure 8 Is used to describe Figure 7 FIG. 1 is a diagram of an example of selecting one pixel row on which a mobility sensing operation is performed in a method of FIG.

[0073] Reference Figure 1 and Figure 7In a method of operating an OLED display device 100 including a display panel 110 having a plurality of pixel rows PXR1, PXR2, ..., PXRN, a target mobility determination block 180 selects one pixel row from the plurality of pixel rows PXR1, PXR2, ..., PXRN (S310). In an exemplary embodiment, the target mobility determination block 180 calculates a plurality of pixel row load data of the plurality of pixel rows PXR1, PXR2, ..., PXRN based on input image data IDAT of the plurality of pixel rows PXR1, PXR2, ..., PXRN (S320), and selects one pixel row having the maximum pixel row load data among the plurality of pixel row load data of the plurality of pixel rows PXR1, PXR2, ..., PXRN (S330). For example, the target mobility determination block 180 may calculate a first load value of the first pixel row PXR1 from the input image data of only the first pixel row PXR1, calculate a second load value of the second pixel row PXR2 from the input image data of only the second pixel row PXR2, and if the first load value is higher than the second load value and other load values calculated for the remaining pixel rows, the target mobility determination block 180 may select the first pixel row PXR1.

[0074] For example, Figure 8 As shown in , the input image data IDAT corresponding to one frame period may include a plurality of row image data LIDAT1, LIDAT2, ..., LIDATN of a plurality of pixel rows PXR1, PXR2, ..., PXRN, and the target mobility determination block 180 may calculate a plurality of pixel row load data PXRLOAD1, PXRLOAD2, ..., PXRLOADN of the plurality of pixel rows PXR1, PXR2, ..., PXRN based on the plurality of row image data LIDAT1, LIDAT2, ..., LIDATN of the plurality of pixel rows PXR1, PXR2, ..., PXRN, respectively. For example, the target mobility determination block 180 may calculate each pixel row load data (e.g., PXRLOAD1) by dividing the average value or the sum of the pixel data included in the corresponding row image data (e.g., LIDAT1) by the maximum image data of one pixel row or the average value or the sum of the maximum row image data. In addition, the target mobility determination block 180 can determine the maximum pixel row load data among multiple pixel row load data PXRLOAD1, PXRLOAD2, ..., PXRLOADN, and can select a pixel row having the maximum pixel row load data among multiple pixel rows PXR1, PXR2, ..., PXRN.

[0075] The target mobility determination block 180 may determine the load data based on the input image data IDAT of the selected pixel row (S340). For example, since the pixel row having the largest pixel row load data is selected, the target mobility determination block 180 may determine the largest pixel row load data among the plurality of pixel row load data PXRLOAD1, PXRLOAD2, ..., PXRLOADN as the load data.

[0076] The target mobility determination block 180 determines target mobility data TMD corresponding to the load data (S350). In an exemplary embodiment, when the load data is smaller than the reference load data (eg, Figure 2 In the case of the RLD in the reference load data), the target mobility data TMD determined by the target mobility determination block 180 increases as the load data increases, and in the case of the load data being greater than or equal to the reference load data, the target mobility data TMD determined by the target mobility determination block 180 is determined to be the maximum target mobility data corresponding to the reference load data (for example, Figure 2 MTMD in ).

[0077] The sensing circuit 160 generates mobility sensing data MSD corresponding to mobility values of driving transistors of a plurality of pixels included in the selected one pixel row by performing a mobility sensing operation on the selected one pixel row ( S360 ).

[0078] The current control block 190 compares the mobility sensing data MSD with the target mobility data TMD (S370), and may adjust the panel current flowing through the display panel 110 based on the result of the comparison between the mobility sensing data MSD and the target mobility data TMD (S380). In the disclosed exemplary embodiment, the current control block 190 reduces the panel current when the mobility sensing data MSD is greater than the target mobility data TMD, and increases the panel current when the mobility sensing data MSD is less than the target mobility data TMD. For example, to reduce the panel current, the current control block 190 may generate the output image data ODAT by reducing the amplitude of the input image data IDAT, and the data voltage DV applied to the plurality of pixel rows PXR1, PXR2, ..., PXRN is reduced based on the output image data ODAT. Furthermore, to increase the panel current, the current control block 190 may generate output image data ODAT by increasing the amplitude of the input image data IDAT, and the data voltage DV applied to the plurality of pixel rows PXR1, PXR2, ..., PXRN may be increased based on the output image data ODAT. Therefore, in the method of operating the OLED display device 100 according to the disclosed exemplary embodiment, the panel current may be controlled by using the mobility sensing data MSD without requiring a series transistor for sensing the panel current, thereby reducing the cost and power consumption of the OLED display device 100.

[0079] Figure 9 is a flowchart illustrating a method of operating an OLED display device according to a disclosed exemplary embodiment, Figure 10 Is used to describe Figure 9 FIG. 1 is a diagram of an example of selecting one pixel row on which a mobility sensing operation is performed in a method of FIG.

[0080] Reference Figure 1 and Figure 9 In a method of operating an OLED display device 100 including a display panel 110 having a plurality of pixel rows PXR1, PXR2, ..., PXRN, the target mobility determination block 180 selects the uppermost pixel row PXR1 (or the lowermost pixel row PXRN) from the plurality of pixel rows PXR1, PXR2, ..., PXRN (S410). In some exemplary embodiments, as Figure 10As shown in , the display panel 110 includes a power wiring 115 having a grid structure to provide a first power supply voltage ELVDD (e.g., a high power supply voltage) to a plurality of pixels PX. The power wiring 115 is supplied with the first power supply voltage ELVDD at the upper and / or lower portions. Therefore, the temperature change and / or panel current change of the topmost pixel row PXR1 (or the bottommost pixel row PXRN) positioned corresponding to the upper portion (or lower portion) of the power wiring 115 may be greater than the temperature change and / or panel current change of other pixel rows (e.g., PXR2, ..., etc.). Therefore, the target mobility determination block 180 can select the topmost pixel row PXR1 (or the bottommost pixel row PXRN) having the largest temperature change and / or the largest panel current change as a pixel row on which a mobility sensing operation will be performed.

[0081] The target mobility determination block 180 determines load data based on the input image data IDAT of the topmost pixel row PXR1 (or the bottommost pixel row PXRN) (S440), and determines target mobility data TMD corresponding to the load data (S450). The sensing circuit 160 generates mobility sensing data MSD by performing a mobility sensing operation on the topmost pixel row PXR1 (or the bottommost pixel row PXRN) (S460). The current control block 190 compares the mobility sensing data MSD with the target mobility data TMD (S470), and can adjust the panel current flowing through the display panel 110 based on the result of the comparison of the mobility sensing data MSD and the target mobility data TMD (S480). Therefore, in the method of operating the OLED display device 100 according to the disclosed exemplary embodiment, the panel current can be controlled by using the mobility sensing data MSD without the need for a series resistor for sensing the panel current, thereby reducing the cost and power consumption of the OLED display device 100.

[0082] Figure 11 is a flowchart illustrating a method of operating an OLED display device according to a disclosed exemplary embodiment, Figure 12 Is used to describe Figure 11 FIG. 1 is a diagram of an example of selecting one pixel row on which a mobility sensing operation is performed in a method of FIG.

[0083] Reference Figure 1 and Figure 11 In a method of operating an OLED display device 100 including a display panel 110 having a plurality of pixel rows PXR1, PXR2, ..., PXRN, a target mobility determination block 180 sequentially selects the plurality of pixel rows PXR1, PXR2, ..., PXRN so that selection of one pixel row on which a mobility sensing operation is to be performed is changed every frame period (S510). For example, as Figure 12As shown in , each frame period FP1, FP2, ..., FPN may include a vertical blank period VBP and an effective period AP, and the panel driver 120 may perform a mobility sensing operation on one pixel row during the sensing period SP corresponding to the vertical blank period VBP. In an embodiment, all pixel rows of the display panel 110 sequentially receive corresponding data voltages during a single frame period. For example, during part of the frame period, only some pixel rows receive data voltages. In an embodiment, a given pixel row receives a data voltage during the effective period AP of the frame period and does not receive a data voltage during the vertical blank period VBP of the frame period. In addition, the panel driver 120 may perform a mobility sensing operation on the first pixel row PXR1 during the sensing period SP of the first frame period FP1, and may perform a mobility sensing operation on the second pixel row PXR2 during the sensing period SP of the second frame period FP2. In this way, the panel driver 120 may perform a mobility sensing operation on the Nth pixel row PXRN during the sensing period SP of the Nth frame period FPN, where N is an integer greater than 1. Therefore, the target mobility determination block 180 may select N pixel rows PXR1 , PXR2 , . . . , PXRN in N frame periods FP1 , FP2 , . . . , FPN, respectively. In the (N+1)th frame period, the first pixel row PXR1 may be selected again.

[0084] The target mobility determination block 180 determines load data based on the input image data IDAT of the selected pixel row (S540) and determines target mobility data TMD corresponding to the load data (S550). The sensing circuit 160 generates mobility sensing data MSD by performing a mobility sensing operation on the selected pixel row (S560). The current control block 190 compares the mobility sensing data MSD with the target mobility data TMD (S570) and can adjust the panel current flowing through the display panel 110 based on the result of the comparison between the mobility sensing data MSD and the target mobility data TMD (S580). In an exemplary embodiment, based on the result of the comparison in each frame period (e.g., FP1), the current control block 190 adjusts the panel current in the next frame period (e.g., FP2). For example, the result of the comparison of the previous frame period can be used to adjust the panel current in the next frame period. In an exemplary embodiment, based on the sum of the results of the comparison in N frame periods FP1, FP2, ..., FPN, the current control block 190 adjusts the panel current in the next frame period or the N+1 frame period. For example, if N=2 (i.e., based on the sum of the results of the comparisons in two frame periods), a first comparison is performed for the first pixel row PXR1 during the first frame period FP1, a second comparison is performed for the second pixel row PXR2 during the second frame period FP2, and the sum of the results of the first comparison and the second comparison is used to adjust the panel current during the third frame period. In addition, based on the sum of the results of the comparisons in the second frame period FP2 to the N+1 frame period, the current control block 190 can adjust the panel current in the N+2 frame period. For example, if N remains at 2, a third comparison is performed for the third pixel row during the third frame period, and the sum of the results of the second comparison and the third comparison is used to adjust the panel current during the fourth frame period. Therefore, in the method of operating the OLED display device 100 according to an exemplary embodiment, the panel current can be controlled by using the mobility sensing data MSD without the need for a series transistor for sensing the panel current, and thus, the cost and power consumption of the OLED display device 100 can be reduced.

[0085] Figure 13 is a flowchart illustrating a method of operating an OLED display device according to a disclosed exemplary embodiment.

[0086] Reference Figure 1 and Figure 13In a method of operating an OLED display device 100 including a display panel 110 having a plurality of pixel rows PXR1, PXR2, ..., PXRN, a target mobility determination block 180 selects one pixel row from the plurality of pixel rows PXR1, PXR2, ..., PXRN on which a mobility sensing operation is to be performed (S610), determines load data based on input image data IDAT of the selected pixel row (S640), and determines target mobility data TMD corresponding to the load data (S650). The sensing circuit 160 generates mobility sensing data MSD by performing a mobility sensing operation on the selected pixel row (S660). The current control block 190 compares the mobility sensing data MSD with the target mobility data TMD (S670). Depending on whether the difference between the mobility sensing data MSD and the target mobility data TMD satisfies a shutdown reference time and a shutdown reference amount, the overcurrent protection circuit 195 included in the current control block 190 selectively stops the operation of the OLED display device 100 (S680 and S685). For example, if the difference is within a specific range within a specific amount of time, the operation of the OLED display device 100 is stopped. If the difference between the mobility sensing data MSD and the target mobility data TMD does not satisfy the off-reference time and the off-reference amount (S680: No), the operation of the OLED display device 100 is not stopped. The current control block 190 adjusts the panel current flowing through the display panel 110 according to the result of the comparison of the mobility sensing data MSD and the target mobility data TMD (S690).

[0087] If the difference between the mobility sensing data MSD and the target mobility data TMD satisfies the off-reference time and the off-reference amount (S680: Yes) or if the mobility sensing data MSD is greater than the target mobility data TMD by more than the off-reference amount during a plurality of frame periods (e.g., 60 frame periods) corresponding to the off-reference time, the overcurrent protection circuit 195 determines that an overcurrent has occurred in the display panel 110 and stops the operation of the OLED display device 100 (S685). Therefore, in the OLED display device 100 according to the disclosed exemplary embodiment, since the overcurrent is detected by using the mobility sensing data MSD, even if the load data indicates a low load, the overcurrent can be accurately detected, and the overcurrent protection operation of the overcurrent protection circuit 195 can be performed normally.

[0088] Figure 14 is a block diagram illustrating an electronic device including an OLED display device according to a disclosed exemplary embodiment.

[0089] Reference Figure 14, the electronic device 1100 includes a processor 1110, a memory device 1120, a storage device 1130, an input / output (I / O) device 1140, a power supply 1150, and an OLED display device 1160. The electronic device 1100 may also include a plurality of ports for communicating with a video card, a sound card, a memory card, a universal serial bus (USB) device, other electrical devices, and the like.

[0090] The processor 1110 may perform various computing functions or tasks. The processor 1110 may be an application processor (AP), a microprocessor, a central processing unit (CPU), or the like. The processor 1110 may be coupled to other components via an address bus, a control bus, a data bus, or the like. In addition, in some exemplary embodiments, the processor 1110 may also be coupled to an expansion bus such as a peripheral component interconnect (PCI) bus.

[0091] The memory device 1120 may store data used for the operation of the electronic device 1100. For example, the memory device 1120 may include at least one nonvolatile memory device (such as an erasable programmable read-only memory (EPROM) device, an electrically erasable programmable read-only memory (EEPROM) device, a flash memory device, a phase change random access memory (PRAM) device, a resistive random access memory (RRAM) device, a nano-floating gate memory (NFGM) device, a polymer random access memory (PoRAM) device, a magnetic random access memory (MRAM) device, a ferroelectric random access memory (FRAM) device, etc.) and / or at least one volatile memory device (such as a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, a mobile dynamic random access memory (mobile DRAM) device, etc.).

[0092] The storage device 1130 may be a solid-state drive (SSD), a hard disk drive (HDD), a CD-ROM, or the like. The I / O device 1140 may be an input device (such as a keyboard, a keypad, a mouse, a touch screen, or the like) and an output device (such as a printer, a speaker, or the like). The power supply 1150 may provide power for the operation of the electronic device 1100. The OLED display device 1160 may be coupled to other components via a bus or other communication link.

[0093] In the OLED display device 1160 according to the disclosed exemplary embodiments, a pixel row is selected from a plurality of pixel rows, load data is determined based on input image data of the selected pixel row, target mobility data corresponding to the load data is determined, a mobility sensing operation is performed on the selected pixel row to generate mobility sensing data, and the panel current can be adjusted by comparing the mobility sensing data with the target mobility data. Therefore, the OLED display device 1160 can control the panel current by using the mobility sensing data without requiring a series resistor for sensing the panel current, thereby reducing the cost and power consumption of the OLED display device 1160. Furthermore, in some exemplary embodiments, the OLED display device 1160 can perform an overcurrent protection operation by using the mobility sensing data.

[0094] The inventive concept may be applied to any electronic device 1100 including the OLED display device 1160. For example, the inventive concept may be applied to a television (TV), a digital TV, a 3D TV, a smart phone, a wearable electronic device, a tablet computer, a mobile phone, 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 controller, a navigation device, and the like.

[0095] Although some exemplary embodiments have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without departing substantially from the inventive concept. Therefore, all such modifications are intended to be included within the scope of the inventive concept.

Claims

1. An organic light emitting diode display device, comprising: A display panel including a plurality of pixel rows and a panel driver configured to drive the display panel, the panel driver comprising: a determination circuit configured to select one pixel row from the plurality of pixel rows, determine load data based on input image data of the selected one pixel row, and determine target mobility data corresponding to the load data; a sensing circuit configured to generate mobility sensing data by performing a mobility sensing operation on the selected one pixel row, the mobility sensing data corresponding to mobility values of driving transistors of a plurality of pixels included in the selected one pixel row; and a current control circuit configured to compare the mobility sensing data with the target mobility data to generate a result, and adjust a panel current flowing through the display panel according to the result, The current control circuit reduces the panel current when the mobility sensing data is greater than the target mobility data, and increases the panel current when the mobility sensing data is less than the target mobility data.

2. The organic light emitting diode display device according to claim 1, wherein: The determination circuit calculates a plurality of pixel row load data of the plurality of pixel rows based on input image data of the plurality of pixel rows, and selects the one pixel row having the maximum pixel row load data among the plurality of pixel row load data of the plurality of pixel rows.

3. The organic light emitting diode display device according to claim 1, wherein: The selected one pixel row is an uppermost pixel row or a lowermost pixel row among the plurality of pixel rows.

4. The organic light emitting diode display device according to claim 1, wherein: The determination circuit sequentially selects the plurality of pixel rows so that selection of the one pixel row is changed every frame period.

5. The organic light emitting diode display device according to claim 1, wherein: The determination circuit calculates the load data by dividing the input image data of the selected one pixel row by the maximum image data of the one pixel row.

6. The organic light emitting diode display device according to claim 1, wherein: When the load data is greater than or equal to reference load data, the determination circuit determines the target mobility data as maximum target mobility data corresponding to the reference load data.

7. The organic light emitting diode display device according to any one of claims 1 to 6, wherein: The panel driver further includes: An overcurrent protection circuit is configured to stop the operation of the organic light emitting diode display device when the mobility sensing data is greater than the target mobility data by more than a turn-off reference amount during a plurality of frame periods corresponding to a turn-off reference time.

8. A method for operating the organic light emitting diode display device according to any one of claims 1 to 7, the method comprising: selecting a pixel row from the plurality of pixel rows; determining payload data based on the input image data of the selected one pixel row; determining target mobility data corresponding to the load data; generating mobility sensing data by performing a mobility sensing operation on the selected one pixel row, the mobility sensing data corresponding to mobility values of driving transistors of a plurality of pixels included in the one pixel row; comparing the mobility sensing data and the target mobility data to generate a result; as well as The panel current flowing through the display panel is adjusted according to the result.

Images