Display driving circuit and display device including the same

Abstract

A display driving circuit includes: a data driver configured to provide a driving signal to a plurality of pixels of a display panel and sense an electrical characteristic of each of the plurality of pixels; and a degradation compensation circuit configured to generate and store an accumulated degradation value by accumulating the degradation value of each pixel block in a plurality of pixel blocks within a unit time based on driving data corresponding to the driving signal, correcting the accumulated degradation value of a first pixel block based on sensing data received from the data driver, and performing data compensation based on the accumulated degradation value and a degradation model to compensate for pixel degradation, wherein each pixel block includes at least one pixel.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the priority of Korean Patent Application No. 10-2019-0060224 filed on May 22, 2019, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The inventive concept relates to a semiconductor device, and more particularly, to a display driving circuit for driving a display panel to display an image and a display device including the display driving circuit. Background Art

[0004] Typically, a display device includes a display panel for displaying an image and a display driving circuit for driving the display panel. The display driving circuit can drive the display panel by receiving image data and applying an image signal corresponding to the image data to a data line of the display panel. Recently, the use of organic light emitting diode ("OLED") display panels is increasing. In an OLED display panel, each of a plurality of pixels of a pixel array includes an OLED. In an OLED display panel, when electrical characteristics such as a threshold voltage and a current mobility of a driving transistor included in each pixel degrade, the image quality of the OLED display is reduced. In order to prevent pixel degradation, a degradation model method or a feature sensing method can be used. In the degradation model method, the degradation degree is estimated by using a degradation value accumulated based on input data and by degradation modeling, and the input data is compensated based on the estimated degradation degree. In the feature sensing method, the degradation degree is calculated based on the electrical characteristics, and the input data is compensated based on the degradation degree. Summary of the invention

[0005] According to an exemplary embodiment of the present invention, a display driving circuit includes a data driver configured to provide a driving signal to a plurality of pixels of a display panel and sense an electrical characteristic of each of the plurality of pixels; and a degradation compensation circuit configured to generate and store an accumulated degradation value by accumulating a degradation value of each of a plurality of pixel blocks within a unit time based on driving data corresponding to the driving signal, correct the accumulated degradation value of a first pixel block based on sensing data received from the data driver, and perform data compensation based on the accumulated degradation value and a degradation model to compensate for pixel degradation, wherein each pixel block includes at least one pixel.

[0006] According to another exemplary embodiment of the present invention, a display device includes a display panel, which includes a plurality of pixels divided into a plurality of pixel blocks; a data driver, configured to provide a driving signal to each of the plurality of pixels and sense an electrical characteristic of each of the plurality of pixels; and a degradation compensation circuit, configured to compensate input data corresponding to each of the plurality of pixels based on a compensation rate of the pixel corresponding to the input data, and provide the compensated input data to the data driver, wherein the degradation compensation circuit is further configured to generate and accumulate a degradation value of each of the plurality of pixels based on driving data corresponding to the driving signal provided to each of the plurality of pixels, calculate the compensation rate of each of the plurality of pixels by using the accumulated degradation value of each pixel and a degradation model, and correct the accumulated degradation value of each of the plurality of pixels based on the sensed electrical characteristic.

[0007] According to another exemplary embodiment of the present invention, an operating method of a display driving circuit for driving a display panel having a plurality of pixel blocks includes: generating a plurality of accumulated degradation values ​​by calculating and accumulating a degradation value of each of the plurality of pixel blocks based on driving data provided to each of the plurality of pixel blocks, wherein each of the plurality of pixel blocks includes at least one pixel; determining at least one pixel block as a sensing pixel block based on the plurality of accumulated degradation values; sensing an electrical characteristic of the sensing pixel block; correcting the accumulated degradation value corresponding to the sensing pixel block to match a degradation rate based on the sensing data; and performing degradation compensation on the plurality of pixel blocks based on the plurality of accumulated degradation values.

[0008] According to another exemplary embodiment of the inventive concept, a display driving circuit includes: a data driver configured to provide a driving signal to a plurality of pixels of a display panel and sense an electrical characteristic of each of the plurality of pixels; and a degradation compensation circuit configured to store a plurality of accumulated degradation values ​​of a first frame in a memory, wherein each accumulated degradation value corresponds to a corresponding one of a plurality of pixel blocks, determine a sensing pixel block of the plurality of pixel blocks based on the plurality of accumulated degradation values, and correct the accumulated degradation value corresponding to the sensing pixel block based on sensing data obtained from the sensing pixel block. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above and other features of the inventive concept will be more clearly understood by describing in detail exemplary embodiments in conjunction with the accompanying drawings, in which:

[0010] Figure 1 is a block diagram of a display device according to an exemplary embodiment of the inventive concept;

[0011] Figure 2 is a block diagram of a degradation compensation block according to an exemplary embodiment of the inventive concept;

[0012] Figure 3 is a diagram showing an example of a degradation model;

[0013] Figure 4 is a flowchart of a data compensation method of a display device according to an exemplary embodiment of the inventive concept;

[0014] Figure 5 is a diagram for explaining a data compensation method according to an exemplary embodiment of the inventive concept;

[0015] Figure 6 is a block diagram of a driving block of a data driver according to an exemplary embodiment of the inventive concept;

[0016] Figure 7 is a block diagram of a sensing block of a data driver according to an exemplary embodiment of the inventive concept;

[0017] Figure 8 An equivalent circuit of a pixel according to an exemplary embodiment of the inventive concept is shown;

[0018] Fig. 9 is shown in more detail Figure 2 A diagram of the operation of a data compensator;

[0019] Fig. 10A and 10B Shows Figure 2 The operation of the accumulator;

[0020] Fig.11 Shows Figure 2 The operation of the accumulator;

[0021] Fig.12 Shows Figure 2 The operation of the sensing controller;

[0022] Fig.13 is a graph showing the relationship between temperature characteristics and degradation rate;

[0023] Fig.14 Shows Figure 2 The operation of the corrector;

[0024] Fig.15A and Fig. 15B illustrates a process of correcting an accumulated degradation value by a degradation compensation block under a low temperature condition and a high temperature condition according to an exemplary embodiment of the inventive concept;

[0025] Fig.16 is a flowchart of a data compensation method of a display device according to an exemplary embodiment of the inventive concept;

[0026] Fig.17is a flowchart of a data compensation method of a display device according to another exemplary embodiment of the inventive concept;

[0027] Fig.18 shows a display device according to an exemplary embodiment of the inventive concept; and

[0028] Fig.19 A display device according to another exemplary embodiment of the inventive concept is illustrated. DETAILED DESCRIPTION

[0029] Hereinafter, exemplary embodiments of the inventive concept are described with reference to the accompanying drawings.

[0030] Figure 1 is a block diagram of a display device according to an exemplary embodiment of the inventive concept.

[0031] The display device 1 according to the exemplary embodiment of the present invention can be set in an electronic device having an image display function. Examples of electronic devices may include smart phones, tablet personal computers (PCs), portable multimedia players (PMPs), cameras, wearable devices, televisions, digital video disk (DVD) players, refrigerators, air conditioners, air purifiers, set-top boxes, robots, drones, various types of medical equipment, navigation equipment, global positioning system (GPS) receivers, advanced driver assistance systems (ADAS), vehicle-mounted equipment, furniture, various measuring instruments, etc.

[0032] Reference Figure 1 , the display device 1 may include a display driving circuit 10 and a display panel 20, and the display driving circuit 10 may include a timing controller 200, a data driver 100, and a gate driver 300. In an exemplary embodiment of the inventive concept, the display driving circuit 10 and the display panel 20 may be implemented as one module. For example, the display driving circuit 10 may be mounted on a circuit film such as a tape carrier package (TCP), a chip on film (COF), or a flexible printed circuit (FPC), and then mounted on the display panel 20 by a tape automated bonding (TAB) method, or mounted on a non-display area of ​​the display panel 20 by a chip on glass (COG) method.

[0033] The display panel 20 may include a plurality of signal lines (eg, a plurality of gate lines GL, a plurality of data lines DL, and a plurality of sensing lines SL) and a plurality of pixels PX (eg, a pixel array arranged in a matrix form).

[0034] Each of the plurality of pixels PX may display a color in red, green, and blue, and a pixel displaying red, a pixel displaying green, and a pixel displaying blue may be arranged repeatedly in sequence. A user may recognize light as a mixture of red light, green light, and blue light displayed by adjacent pixels PX. In an exemplary embodiment of the inventive concept, a pixel displaying red, a pixel displaying green, and a pixel displaying blue may be referred to as a red sub-pixel, a green sub-pixel, and a blue sub-pixel, respectively, and a group of a red sub-pixel, a green sub-pixel, and a blue sub-pixel may be referred to as a pixel. In an exemplary embodiment of the inventive concept, each of the plurality of pixels PX may display one of red, green, blue, and white. However, the inventive concept is not limited thereto, and the color displayed by a pixel may vary.

[0035] In an exemplary embodiment of the present inventive concept, the display panel 20 may be an organic light emitting diode (OLED) display panel, in which each pixel PX includes a light emitting element, such as an OLED. However, the present inventive concept is not limited thereto, and the display panel 20 may be a flat panel display of different types or a flexible display panel.

[0036] The gate driver 300 may drive the plurality of gate lines GL of the display panel 20 by using the gate driver control signal GCS (e.g., gate timing control signal) received from the timing controller 200. The gate driver 300 may apply a pulse of a gate-on voltage, such as a scan voltage or a sensing-on voltage, to each of the plurality of gate lines GL based on the gate control signal GCS when driving each of the plurality of gate lines GL.

[0037] The data driver 100 includes a driving block 110 and a sensing block 120 , and may drive a plurality of pixels PX through a plurality of data lines DL, and may sense (eg, measure) electrical characteristics of the plurality of pixels PX through sensing lines SL.

[0038] The driving block 110 may perform digital-to-analog conversion on image data (e.g., compensated input data CDT (also referred to as “compensation data”) of each pixel in the plurality of pixels PX received from the timing controller 200), and provide a driving signal, which is an analog signal converted from the input data, to the display panel 20 via the data line DL. Each driving signal may be provided to one of the plurality of pixels PX.

[0039] In the display mode or the sensing mode, the driving block 110 may convert the image data provided from the timing controller 200 or the internally set data for sensing into a driving signal, such as a driving voltage, and output the driving voltage to the data line DL of the display panel 20. The driving block 110 may include a Figure 6 A plurality of channel drivers are shown, and each of the plurality of channel drivers can convert received data (eg, compensated input data CDT) into a driving signal. The plurality of channel drivers perform digital-to-analog conversion, and thus can be referred to as digital-to-analog converters.

[0040] The sensing block 120 may periodically or non-periodically measure electrical characteristics of the plurality of pixels PX. The sensing block 120 may sense (e.g., measure) electrical characteristics of the plurality of pixels PX in a sensing mode. The sensing mode may be set during manufacture of the display device 1, a booting period after the display device 1 is powered on, an end period of a power-off period, or a dummy interval (or vertical blanking interval) between frame display periods of the display panel 20.

[0041] The sensing block 120 may receive a sensing signal representing an electrical characteristic of each of the plurality of pixels PX, for example, a pixel voltage or a pixel current, through the plurality of sensing lines SL and analog-to-digital-convert the sensing signal into sensing data SDT.

[0042] The timing controller 200 can control the overall operation of the display device 1 based on the control command CMD received from the external processor, and control the driving timing of the data driver 100 and the gate driver 300. The external processor may be, for example, a main processor or an image processor of an electronic device on which the display device 1 is mounted. The timing controller 200 may be embodied by hardware, software, or a combination of hardware and software. For example, the timing controller 200 may be implemented by a digital logic circuit and a register that perform the functions described below.

[0043] The timing controller 200 may provide a data driver control signal DCS to the data driver 100. Operations of the driving block 110 and the sensing block 120 of the data driver 100 and points of time at which the driving block 110 and the sensing block 120 are to be operated may be controlled in response to the data driver control signal DCS.

[0044] In addition, the timing controller 200 may provide the gate driver control signal GCS to the gate driver 300. As described above, the gate driver 300 may drive the plurality of gate lines GL of the display panel 20 in response to the gate driver control signal GCS.

[0045] In addition, the timing controller 200 may perform various image processing operations on the image data received from the external processor, for example, to change the format of the image data or reduce power consumption. The image data may include a pixel corresponding to each pixel PX. Figure 2The timing controller 200 may perform data compensation on the image data IDT of each pixel PX of the display panel 20 and provide the compensation data CDT to the data driver 100. To achieve this, the timing controller 200 may include a degradation compensation block 210.

[0046] The degradation compensation block 210 may divide the plurality of pixels PX into a plurality of pixel blocks PXB, calculate an accumulated degradation value of each of the plurality of pixel blocks PXB, and perform data compensation for the plurality of pixel blocks PXB based on the calculated accumulated degradation value and a degradation model.

[0047] The plurality of pixel blocks PXB may include pixels PX arranged adjacent to each other. Figure 1 An example is shown in which the pixel block PXB includes 2×2 pixels PX arranged in two rows and two columns. However, the inventive concept is not limited thereto, and the size of the pixel block PXB may vary. In an exemplary embodiment of the inventive concept, the degradation compensation block 210 may calculate an accumulated degradation value of each of the plurality of pixels PX based on the calculated accumulated degradation value and the degradation model, and perform data compensation with respect to the corresponding pixel PX.

[0048] The accumulated degradation value may be obtained by accumulating the degradation values ​​calculated for a specific period of time (e.g., in units of frames) based on the compensated input data of the pixel PX supplied to the pixel block PXB or the drive data corresponding to the drive signal supplied to the pixel PX. The drive data is obtained by reflecting the brightness characteristics and the gamma characteristics into the compensated input data, and the drive data may be a digital value representing the level (e.g., voltage) of the drive signal.

[0049] In addition, the degradation compensation block 210 may correct the accumulated degradation value based on the sensing data SDT received from the data driver 100. The degradation compensation block 210 may select at least one pixel block PXB having a high degree of degradation from a plurality of pixel blocks PXB as a sensing pixel block whose electrical characteristics are to be sensed, and control the sensing block 120 of the data driver 100 to sense the electrical characteristics of the sensing pixel block. The degradation compensation block 210 may correct the accumulated degradation value corresponding to the sensing pixel block based on the sensing data SDT received from the data driver 100. The degradation compensation block 210 may perform data compensation on the sensing pixel block based on the corrected accumulated degradation value, and perform data compensation on other pixel blocks based on the accumulated degradation value corresponding thereto. In an exemplary embodiment of the inventive concept, the sensing period for sensing the electrical characteristics of the selected sensing pixel block may be equal to or longer than the accumulation period of the accumulated degradation value. In addition, the period for performing data sensing on one pixel block may be longer than the accumulation period. The configuration and operation of the degradation compensation block 210 will be described in detail below.

[0050] As described above, the display device 1 according to the exemplary embodiment of the present inventive concept can calculate the accumulated degradation value of each of the plurality of pixel blocks PXB based on the degradation model method, perform data compensation based on the accumulated degradation value, selectively generate the actual degradation rate of at least one pixel block PXB according to the feature sensing method, and correct the accumulated degradation value based on the actual degradation rate, thereby improving the consistency ratio between the accumulated degradation value and the actual degradation rate.

[0051] When only the degradation model method is used for data compensation to prevent image quality degradation due to pixel degradation, when the consistency ratio between the degradation model and the actual degradation rate is low according to the driving environment, the data compensation efficiency may be reduced. In addition, even when data compensation is performed, the actual degree of degradation is not reflected, and therefore, the luminous uniformity and image quality of the display panel 20 may be reduced.

[0052] In addition, when only the feature sensing method is used for data compensation, time for sensing the feature (e.g., time for driving the sensing mode) is additionally required, and the feature is sensed in real time for the degraded area. However, when the electrical feature is sensed while the display is driven, an undesirable image may be output on the display panel 20.

[0053] However, the display device 1 according to the exemplary embodiment of the present invention uses the accumulated degradation value to perform data compensation based on the degradation model method, and corrects the accumulated degradation value based on the feature sensing method. Therefore, it is not necessary to perform feature sensing in real time. Therefore, even in the case where feature sensing detection is not performed on the pixel block, the restriction on the feature sensing cycle can be relaxed, the consistency ratio between the accumulated degradation value and the actual degradation rate can be improved, and data compensation can be performed based on the accumulated degradation value. Therefore, the light emission uniformity and reliability of the display panel 20 can be improved.

[0054] Figure 2 is a schematic block diagram of a degradation compensation block according to an exemplary embodiment of the inventive concept. Figure 2 Shows Figure 1 An example of the degradation compensation block 210 is shown in FIG. Figure 1 The above description of the degradation compensation block 210 is applicable to Figure 2 Embodiment of the invention.

[0055] Reference Figure 2 The degradation compensation block 210 may include a data compensator 211 , an accumulator 212 , a nonvolatile memory 213 , a sense controller 214 , and a corrector 215 .

[0056] The data compensator 211 may generate the compensation data CDT by performing data compensation on the input data IDT using the accumulated degradation value and the degradation model. In this case, the degradation model may be expressed as follows: Figure 3 The relationship between the accumulated degradation value and the degradation rate is shown.

[0057] Figure 3 is a diagram showing an example of a degradation model. Figure 3 In FIG. 1 , the horizontal axis represents the accumulated degradation value ADV, and the vertical axis represents the degradation rate DR. Assuming that the pixel or the pixel group continuously receives the same driving signal, the accumulated degradation value ADV can be represented over time t.

[0058] The degradation rate DR is an indicator indicating the degree of degradation of a pixel or a pixel group, and can be expressed, for example, as a ratio of the current brightness CL to the initial brightness IL. When the accumulated degradation value ADV is small, for example, at the start of driving of the display panel 20, the degradation rate DR is high, for example, "1". However, as the light emission time of the pixel increases due to the driving of the display panel 20, the accumulated degradation value ADV may increase and the degradation rate DR may decrease.

[0059] Return to reference Figure 2 The data compensator 211 may convert the accumulated degradation value of each of the plurality of pixel blocks into a degradation rate by using a degradation model, and perform data compensation on the input data IDT based on the plurality of degradation rates corresponding to the plurality of pixel blocks. The input data IDT represents the grayscale level (gradation) of the driving signal to be applied to the pixel. The data compensator 211 may increase or decrease the grayscale level of the driving signal through data compensation. The compensation data CDT may be provided to Figure 1 The driving block 110 of the data driver 100 in FIG.

[0060] The accumulator 212 may receive the compensation data CDT, and calculate and accumulate the degradation value based on the compensation data CDT to generate an accumulated degradation value. The accumulated degradation value indicates the degree of degradation of the pixel over time, and thus will be Figure 1 The accumulated degradation value should not be reset or lost. Therefore, the accumulator 212 can store the accumulated degradation value in the non-volatile memory 213 so that even when the accumulator 212 is reset or lost, the accumulated degradation value can be updated over time. Figure 1 The accumulated degradation value is not lost even when the power supply to the display device 1 is interrupted.

[0061] The non-volatile memory 213 may include a read-only memory (ROM), a programmable ROM (PROM), an electrically programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a flash memory, a phase change RAM (PRAM), a magnetic RAM (MRAM), a resistive RAM (RRAM), a ferroelectric RAM (FRAM), etc. Here, "RAM" refers to a random access memory. In an exemplary embodiment of the inventive concept, the non-volatile memory 213 may be embodied as a part of the accumulator 212.

[0062] The sensing controller 214 may select at least one pixel block on which electrical characteristic sensing is to be performed based on a plurality of accumulated degradation values ​​corresponding to a plurality of pixel groups, and control Figure 1 The sensing block 120 of the data driver 100 performs electrical characteristic sensing on a sensing pixel block selected according to a sensing period or a region including the selected sensing pixel block.

[0063] The sensing controller 214 may provide a sensing control signal SCS to the sensing block 120. The sensing block 120 may perform electrical characteristic sensing on the sensing pixel block in response to the sensing control signal SCS. In an exemplary embodiment of the inventive concept, the sensing control signal SCS may include information about a sensing period, a position of the sensing pixel block, a sensing method, and the like. The sensing method may include, for example, measuring a threshold voltage of a driving transistor included in a pixel, measuring a potential difference at both ends of a light emitting element provided in a pixel, or measuring an amount or mobility of a current flowing through a light emitting element.

[0064] The corrector 215 may correct the accumulated degradation value of the sensing pixel block based on the sensing data SDT received from the sensing block 120 of the data driver 100. The sensing data SDT may include a threshold voltage of a driving transistor included in a pixel, a potential difference at both ends of a light emitting element provided in the pixel, or an amount or mobility of current flowing through the light emitting element.

[0065] The corrector 215 may obtain the accumulated degradation value of the sensing pixel block from the nonvolatile memory 213 and correct the accumulated degradation value based on the sensing data SDT. The corrector 215 may store the corrected accumulated degradation value in the nonvolatile memory 213 as the accumulated degradation value of the sensing pixel block.

[0066] Thereafter, in order to perform data compensation on the input data IDT received from the subsequent frame, the data compensator 211 may perform data compensation on the input data IDT corresponding to the sensing pixel block among the multiple pixel blocks based on the corrected accumulated degradation value, and perform data compensation on the input data IDT corresponding to other pixel blocks based on the accumulated degradation value generated and stored by the accumulator 212.

[0067] Figure 4 is a flowchart of a data compensation method of a display device according to an exemplary embodiment of the inventive concept.

[0068] Reference Figure 2 and Figure 4 The accumulator 212 may calculate degradation values ​​of a plurality of pixel blocks and accumulate the calculated degradation values ​​( S110 ). As the calculated degradation values ​​are accumulated, an accumulated degradation value may be obtained, and the accumulator 212 may store the accumulated degradation value in the nonvolatile memory 213 .

[0069] The sensing controller 214 may determine the sensing pixel block whose electrical characteristics are to be sensed based on the multiple accumulated degradation values ​​of the multiple pixel blocks (S120). The sensing controller 214 may determine at least one pixel block having a relatively high accumulated degradation value among the multiple pixel blocks as a sensing pixel block. The degree of degradation of the sensing pixel block having a higher accumulated degradation value may be higher than the degree of degradation of other pixel blocks. When the degree of degradation is high, the consistency ratio between the accumulated degradation value and the degradation rate may be reduced. Therefore, the sensing controller 214 may control the electrical data sensing to be performed on the sensing pixel block to correct the accumulated degradation value of the pixel block whose degree of degradation is estimated to be the highest.

[0070] Figure 1 The sensing block 120 may sense (e.g., measure) an electrical characteristic of the sensing pixel block under the control of the sensing controller 214 (S130). As described above, the sensing block 120 may sense at least one of various electrical characteristics. The sensing block 120 may provide sensing data indicating the sensed electrical characteristic to the corrector 215.

[0071] The corrector 215 may correct the accumulated degradation value of the sensing pixel block based on the sensing data ( S140 ).

[0072] The data compensator 211 may perform data compensation on the plurality of pixel blocks based on the plurality of accumulated degradation values ​​(S150). In this case, the accumulated degradation values ​​of the sensing pixel blocks may be accumulated degradation values ​​corrected based on the sensing data.

[0073] After data compensation is performed, operations S110 to S150 may be performed again to generate an accumulated degradation value based on the compensated data and correct the accumulated degradation value based on the sensing data.

[0074] Figure 5 is used to explain a data compensation method according to an exemplary embodiment of the inventive concept. Figure 5 The data compensation method can be obtained by Figure 2 The degradation compensation block 210 performs

[0075] Reference Figure 5, the display panel 20 may include a plurality of pixel blocks PXB11 to PXBmn (herein, m and n are integers greater than or equal to 2), and each of the plurality of pixel blocks PXB11 to PXBmn may include at least one pixel.

[0076] In the Nth frame, the accumulated degradation values ​​(e.g., multiple accumulated degradation values ​​ADV(N)) corresponding to the multiple pixel blocks PXB11 to PXBmn, respectively, may be stored in the nonvolatile memory 213. The sensing pixel block may be determined based on the multiple accumulated degradation values ​​ADV(N). For example, when the accumulated degradation value ADV22 among the multiple accumulated degradation values ​​ADV(N) is the largest, the pixel block PXB22 corresponding to the accumulated degradation value ADV22 may be determined as the sensing pixel block. Electrical characteristic sensing may be performed on the pixel block PXB22, and sensing data SDT may be generated. The accumulated degradation value ADV22 may be corrected based on the sensing data SDT. Therefore, the updated accumulated degradation value ADV'(N) of the Nth frame may be stored.

[0077] In an exemplary embodiment of the inventive concept, the position of the area including the pixel block PXB22 is determined as the detection position SP, and the sensing may be performed on the pixel blocks PXB21 to PXB2n provided at the sensing position SP. In this case, sensing data for the pixel blocks PXB21 to PXB2n may be generated, and the accumulated degradation values ​​ADV21 to ADV2n respectively corresponding to the pixel blocks PXB21 to PXB2n may be corrected based on the sensing data.

[0078] Next, when input data IDT corresponding to the (N+1)th frame is received, data compensation may be performed based on the updated accumulated degradation value ADV′(N) of the Nth frame and the degradation model.

[0079] Thereafter, a plurality of accumulated degradation values ​​ADV(N+1) of the (N+1)th frame may be generated by accumulating (eg, adding) the degradation values ​​DV11 to DVmn generated based on the compensation data to the updated accumulated degradation value ADV′(N) of the Nth frame.

[0080] Figure 6 is a block diagram of a driving block of a data driver according to an exemplary embodiment of the inventive concept. Figure 6 The drive block 110 is Figure 1 Therefore, referring to Figure 1 The above description of the driving block 110 is applicable to the present embodiment.

[0081] Reference Figure 6 , the driving block 110 may include a gamma voltage generator 111 and a plurality of channel drivers 112 .

[0082] The gamma voltage generator 111 may generate a plurality of gamma voltages GV[255:0] based on the gamma control signal GMC. Figure 6 It is illustrated that the gamma voltage generator 111 generates 256 gamma voltages, but the inventive concept is not limited thereto.

[0083] The gamma voltage generator 111 may generate a plurality of gamma voltages GV[255:0] according to a gamma curve set based on the gamma control signal GMC. Figure 1 The timing controller 200 receives the gamma control signal GMC. Each of the multiple gamma voltages GV[255:0] may vary depending on the gamma curve. For example, when the gamma voltage generator 111 generates the gamma voltage GV[255:0] according to the gamma curve for gamma 2.2, the voltage corresponding to the same gray level may be different from that voltage when the gamma voltage generator 111 generates the gamma voltage GV[255:0] according to the gamma curve for gamma 1.0. For example, the 127-grayscale gamma voltage GV

[127] in the case of gamma 2.2 may be different from the 127-grayscale gamma voltage GV

[127] in the case of gamma 1.0. For example, the 127-grayscale gamma voltage GV

[127] in the case of gamma 2.2 may be lower than the 127-grayscale gamma voltage GV

[127] in the case of gamma 1.0. In addition, it may be possible to Figure 1 A gamma curve for gamma 2.2 is set in the display device 1.

[0084] Each of the plurality of channel drivers 112 may receive a plurality of gamma voltages GV[255:0] and output drive signals DS1 to DSk (where k is an integer greater than or equal to 2) corresponding to input data (e.g., compensation data) to corresponding pixels by using the plurality of gamma voltages GV[255:0]. For example, the first channel driver CD1 may output a gamma voltage corresponding to the first compensation data CDT1 among the plurality of gamma voltages GV[255:0] as the drive signal DS1 based on the first compensation data CDT1. The operations of the second channel driver CD2 to the kth channel driver CDk are similar to those of the first channel driver CD1.

[0085] Figure 7 is a block diagram of a sensing block of a data driver according to an exemplary embodiment of the inventive concept. Figure 7 The sensing block 120 is Figure 1 Therefore, referring to Figure 1 The above description of the sensing block 120 may be applied to the current embodiment.

[0086] Reference Figure 7 , the sensing block 120 may include a plurality of sample / hold circuits 121 and an analog-to-digital converter (ADC) 122 .

[0087] Multiple sample / hold circuits 121 can simultaneously sample from Figure 1 The sensing block 120 may receive a plurality of sensing signals SS1 to SSj (here, j is an integer equal to or greater than 2) from the display panel 20, and then sequentially output the sampled signals to the ADC 122. The ADC 122 may generate sensing data SDT by analog-to-digital converting the plurality of sensing signals SS1 to SSj sequentially received from the plurality of sample / hold circuits 121. The sensing block 120 may transmit the sensing data SDT to the corrector 215 of the degradation compensation block 210.

[0088] Figure 8 An equivalent circuit of a pixel according to an exemplary embodiment of the inventive concept is shown. For convenience of explanation, some components of the data driver 100 will be shown together.

[0089] Reference Figure 8 , the pixel PX may include a switching transistor SWT, a driving transistor DT, an OLED 25, a storage capacitor Cst, and a sensing transistor SST. However, Figure 8 The configuration and structure of the pixel PX are merely exemplary and thus may be variously changed.

[0090] A first driving voltage ELVDD and a second driving voltage ELVSS may be applied to the pixel PX. The first driving voltage ELVDD may be higher than the second driving voltage ELVSS.

[0091] The switching transistor SWT, the sensing transistor SST, and the driving transistor DT may be an amorphous silicon (a-Si) thin film transistor (TFT), a polycrystalline silicon (poly-Si) TFT, an oxide TFT, an organic TFT, or the like.

[0092] The gate lines GL connected to the pixel PX may include a first gate line GL-1 and a second gate line GL-2. The switching transistor SWT may be connected to the first gate line GL-1 and the data line DL, and is turned on in response to a scan voltage Vsc applied via the first gate line GL-1 to provide a driving signal DS (e.g., a driving voltage) supplied via the data line DL to the gate node N1 of the driving transistor DT. The driving signal DS may be generated by a digital-to-analog converter (DAC) (e.g., a channel driver) of the data driver 100.

[0093] The sensing transistor SST may be connected to the second gate line GL-2 and the sensing line SL, and may be turned on by the sensing turn-on voltage Vso applied via the second gate line GL-2. In this case, the sensing switch SSW of the data driver 100 may be turned on in response to the initial signal INT to provide the initialization voltage Vint (or reset voltage) to the pixel PX via the sensing line SL. The sensing transistor SST may provide the initialization voltage Vint applied from the data driver 100 to the source node N2 of the driving transistor DT. In the sensing mode, the sensing transistor SST may be turned on to output current from the driving transistor DT or the OLED 25 to the sensing line SL.

[0094] The storage capacitor Cst can store the difference between the data voltage Vd applied to the gate node N1 of the driving transistor DT via the switching transistor SWT and the initialization voltage Vint applied to the source node N2 of the driving transistor DT via the sensing transistor SST, so that the driving voltage Vgs can be applied to the driving transistor DT within a specific time period (for example, the duration of one frame).

[0095] The first driving voltage ELVDD is applied to the drain node of the driving transistor DT, and the driving transistor DT may provide the OLED 25 with a driving current I proportional to the driving voltage Vgs. DT .

[0096] The OLED 25 includes an anode connected to the source node N2 of the driving transistor DT, a cathode to which the second driving voltage ELVSS is applied, and an organic emission layer between the cathode and the anode. The cathode may be a common electrode shared by the pixels. In the OLED 25, when the driving current I DT When the organic emission layer generates light, the intensity of the light can be related to the driving current I DT Proportional. Drive current I DT It can be expressed by the following equation 1.

[0097] [Equation 1]

[0098] I DT =β(Vgs–Vth) 2 =β(Vd-Vint-Vth) 2 ,

[0099] Here, β represents a constant determined by the current mobility of the driving transistor DT, and Vth represents the threshold voltage of the driving transistor DT.

[0100] In the sensing mode, the electrical characteristics of the pixel PX can be measured. The switch transistor SWT can provide the sensing data voltage applied via the data line DL to the drive transistor DT. When the sensing transistor SST is turned on, a current I proportional to the difference between the voltage of the gate node N1 and the voltage of the source node N2 of the drive transistor DT (e.g., the drive voltage Vgs) is DT The current may flow to the sensing line SL, thereby charging a parasitic capacitor (eg, line capacitor Cli) of the sensing line SL.

[0101] According to various sensing sequences, when the voltage of the source node N2 of the driving transistor DT reaches a saturation state, or when the voltage of the source node N2 increases linearly, the sensing signal SS received via the sensing line SL can be converted into sensing data SDT by the ADC. The sensing signal SS measured when the voltage of the source node N2 reaches a saturation state may include information about the threshold voltage Vth of the driving transistor DT. The sensing signal SS measured when the voltage of the source node N2 increases linearly may include information about the current mobility of the driving transistor DT. However, the inventive concept is not limited thereto, and the electrical characteristics may be sensed by various sensing methods or sequences.

[0102] Fig. 9 is shown in more detail Figure 2 FIG. 2 is a diagram of the operation of the data compensator 211.

[0103] Reference Fig. 9 The data compensator 211 may receive the accumulated degradation value ADV and convert the accumulated degradation value ADV into a degradation rate DR based on the degradation model (S211). The data compensator 211 may generate a plurality of degradation rates DR by converting the accumulated degradation values ​​ADV of a plurality of pixel blocks into a plurality of degradation rates DR.

[0104] The data compensator 211 may determine a compensation rate CR based on the degradation rate DR (S212). In an exemplary embodiment of the inventive concept, the data compensator 211 may determine compensation rates CR for a plurality of pixel blocks based on a plurality of degradation rates DR, for example, brightness compensation rates. The data compensator 211 may determine the compensation rate CR of a particular pixel block by comparing the degradation rate DR of the particular pixel block with the degradation rate DR of a pixel block determined to have the lowest degree of degradation (for example, a pixel block having the highest degradation rate DR). For example, when the first degradation rate DR1 of the first pixel block is 0.8 and is the highest, and the second degradation rate DR2 of the second pixel block is 0.5, the data compensator 211 may determine 0.8 / 0.5 (=1.6) as the compensation rate CR of the second pixel block. In the case of the compensation rate CR=1.6, the second degradation rate DR2 of the second pixel block is equal to the first degradation rate DR1. Otherwise, 0.5 / 0.8 (=0.625) may be determined as the compensation rate CR of the first pixel block, at which the first degradation rate DR1 of the first pixel block is equal to the second degradation rate DR2. As described above, the data compensator 211 may calculate the compensation rate CR of each of the plurality of pixel blocks by comparing the plurality of degradation rates DR with each other.

[0105] When receiving the input data IDT, the data compensator 211 may compensate the input data IDT based on the compensation rate CR (S213). For example, when the compensation rate CR of the second pixel block is 1.6, the data compensator 211 may generate grayscale data as compensation data CDT based on the relationship between the grayscale data and the brightness to increase the brightness of the pixels of the second pixel block to 1.6 times. Otherwise, when the compensation rate CR of the first pixel block is 0.625, the data compensator 211 may generate grayscale data as compensation data CDT based on the relationship between the grayscale data and the brightness to reduce the brightness of the pixels of the first pixel block to 0.625 times.

[0106] Fig. 10A and 10B Shows Figure 2 The operation of the accumulator 212.

[0107] Reference Fig. 10A , the accumulator 212 may convert the compensation data CDT output from the data compensator 211 into a degradation value DV (S221). Fig. 10B, when the compensation data CDT of the first pixel block PXB1 has 255 gray levels and the compensation data CDT of the second pixel block PXB2 has 127 gray levels, the degradation value DV of the first pixel block PXB1 may be determined to be 1, and the degradation value DV of the second pixel block PXB2 may be determined to be 0.5. In this case, the maximum gray level that the compensation data CDT may have is 255. The degradation value DV may be determined relative to reference data (e.g., the highest gray level) (or data having the highest value) corresponding to the input voltage of the degradation model.

[0108] The accumulator 212 can accumulate the degradation value DV (S222). The accumulator 212 can generate the accumulated degradation value ADV (N) of the current frame (e.g., the Nth frame) by reading the accumulated degradation value ADV (N-1) of the previous frame (e.g., the (N-1)th frame) (hereinafter referred to as "the previous accumulated degradation value") from the non-volatile memory 213, and then accumulating (e.g., adding) the degradation value DV to the previous accumulated degradation value ADV (N-1).

[0109] Reference Fig. 10B , when the previous accumulated degradation values ​​ADV(N-1) of the first pixel block PXB1 and the second pixel block PXB2 are respectively 0.5, the current accumulated degradation value ADV(N) of the first pixel block PXB1 may be calculated as 1.5 by accumulating 1 and 0.5, and the current accumulated degradation value ADV(N) of the second pixel block PXB2 may be calculated as 1 by accumulating 0.5 and 0.5. The accumulator 212 may store the current accumulated degradation value ADV(N) in the nonvolatile memory 213.

[0110] When receiving the compensation data CDT for a subsequent frame (eg, the (N+1)th frame), the accumulator 212 may calculate and accumulate the degradation value DV according to the above method.

[0111] Reference Fig. 10B , in the (N+1)th frame, when the compensation data CDT of the first pixel block PXB1 has 255 gray levels and the compensation data CDT of the second pixel block PXB2 has 63 gray levels, the degradation value DV of the first pixel block PXB1 can be determined as 1, and the degradation value DV of the second pixel block PXB2 can be determined as 0.25.

[0112] The accumulator 212 may read the accumulated degradation value ADV(N) of the Nth frame from the nonvolatile memory 213 as the previous accumulated degradation value, and add the calculated degradation value DV to the previous accumulated degradation value. Since the previous accumulated degradation values ​​ADV(N) of the first pixel block PXB1 and the second pixel block PXB2 are 1.5 and 1, respectively, the current accumulated degradation value ADV(N+1) of the first pixel block PXB1 may be calculated as 2.5 by adding 1 and 1.5, and the current accumulated degradation value ADV(N+1) of the second pixel block PXB2 may be calculated as 1.25 by adding 0.25 and 1. The accumulator 212 may store the current accumulated degradation value ADV(N+1) in the nonvolatile memory 213.

[0113] Fig.11 Shows Figure 2 The operation of the accumulator 212.

[0114] Reference Fig.11 The accumulator 212 may generate driving data DD by reflecting the gamma characteristics and the set brightness into the compensation data CDT, and calculate and accumulate the degradation value based on the driving data DD.

[0115] For example, the accumulator 212 may receive the compensation data CDT and additionally receive at least one of the gamma control signal GMC or the brightness control signal LC. The accumulator 212 may convert the compensation data CDT into driving data DD based on at least one of the gamma control signal GMC or the brightness control signal LC (S231). The driving data DD is data obtained by reflecting at least one of the gamma characteristic or the brightness characteristic into the compensation data CDT, and may correspond to a level of a driving signal applied to a pixel, such as a voltage.

[0116] The accumulator 212 may convert the driving data DD into a degradation value DV (S232), and add the degradation value DV to the previous accumulated degradation value ADV (N-1) (S233). In other words, the degradation value DV may be added to the previous accumulated degradation value ADV (N-1). Thus, an accumulated degradation value ADV (N) corresponding to the current frame (e.g., the Nth frame) may be generated. The accumulator 212 may store the accumulated degradation value ADV (N) in the nonvolatile memory 213.

[0117] As mentioned above Figure 6As described above, even when the compensation data CDT represents the same grayscale, the level of the driving signal may vary according to the gamma characteristic or the brightness characteristic. Therefore, for the generation of the accumulated degradation value ADV, in order to more accurately reflect the driving signal DS applied to the pixel (in other words, the stress applied to the pixel), the accumulator 212 may convert the compensation data CDT into the driving data DD based on the gamma control signal GMC or the brightness control signal LC, and generate the accumulated degradation value ADV based on the driving data DD.

[0118] Fig.12 Shows Figure 2 Operation of the sensing controller 214.

[0119] Reference Fig.12 , the sensing controller 214 can Figure 2 The non-volatile memory 213 or Figure 2 The accumulator 212 receives a plurality of accumulated degradation values ​​ADV including accumulated degradation values ​​of a plurality of pixel groups, and selects at least one pixel block as a sensing pixel block based on the plurality of accumulated degradation values ​​ADV (S241).

[0120] The sensor controller 214 can control Figure 1 The driving block 110 of the sensing pixel block is used to sense the electrical characteristics of the sensing pixel block (S242). The sensing controller 214 may adjust the sensing period (S243). The sensing controller 214 may adjust the sensing period based on the temperature information Tinfo or the plurality of accumulated degradation values ​​ADV.

[0121] In an exemplary embodiment of the present inventive concept, the sensing controller 214 may reduce the sensing period when the temperature is higher than the reference temperature, and increase the sensing period when the temperature is lower than the reference temperature.

[0122] Fig.13 It is a graph showing temperature characteristics versus degradation rate. The horizontal axis represents time and the vertical axis represents degradation rate DR. A degradation model DM can be generated based on a reference temperature. However, the change in the actual degradation rate DR at a temperature higher or lower than the reference temperature may be different from the degradation model DM. According to the degradation model DM, the change in degradation rate DR from time point t1 to time point t2 may be ΔDRh according to the actual degradation rate R_HT at high temperature, and may be ΔDRl according to the actual degradation rate R_LT at low temperature. The change in degradation rate DR may be relatively large at high temperature and relatively small at low temperature. As the amount of change in the degradation rate increases, the difference between the degradation model DM and the change in the actual degradation rate may increase.

[0123] Therefore, when the temperature is higher than the reference temperature, the sensing controller 214 can reduce the sensing cycle to correct the accumulated degradation rate more frequently. In addition, based on the temperature information Tinfo, when the temperature is lower than the reference temperature, the sensing controller 214 can increase the sensing cycle to reduce the number of corrections of the accumulated degradation rate.

[0124] Fig.14 Shows Figure 2 The operation of the corrector 215.

[0125] Reference Fig.14 , the corrector 215 may calculate a degradation rate based on the sensing data SDT, such as a sensing degradation rate (S251). For example, the corrector 215 may calculate the degradation rate based on the sensing data SDT by using a lookup table or a predefined mathematical formula that defines a relationship between feature data and the degradation rate. The degradation rate calculated based on the sensing data SDT may be referred to as a sensing degradation rate SDR.

[0126] The corrector 215 may convert the sensed degradation rate SDR into a degradation value by using a degradation model (S252). The degradation value generated based on the sensed degradation rate SDR may be referred to as a sensed degradation value SDV.

[0127] The corrector 215 may correct the accumulated degradation value of the sensing pixel block based on the sensing degradation value SDV (S253). In an exemplary embodiment of the inventive concept, the corrector 215 may correct the accumulated degradation value of the sensing pixel block based on the sensing degradation value SDV (S253). Figure 2 The non-volatile memory 213 or Figure 2 The accumulator 212 receives the accumulated degradation value ADVspb of the sensing pixel block, and then calculates the sensing degradation value SDV and the accumulated degradation value ADVspb of the sensing pixel block according to a predetermined mathematical formula to correct the accumulated degradation value. Therefore, the accumulated degradation value ADVspb can reflect the sensing degradation rate SDR close to the actual degradation rate. The corrector 215 can store the corrected accumulated degradation value ADVspb' in the non-volatile memory 213.

[0128] Fig.15A and Fig. 15B The process of correcting the accumulated degradation value by the degradation compensation block under low temperature conditions and high temperature conditions according to an exemplary embodiment of the inventive concept is shown. Here, it is assumed that the same driving signal is continuously received for a pixel or a pixel group. Because there is a linear relationship between time t and the accumulated degradation value ADV, the increase of the accumulated degradation value ADV can be represented according to the passage of time t.

[0129] The degradation model DM may be different from the actual degradation rate AD at low and high temperatures. In this case, the actual degradation rate AD is the same as or similar to the degradation rate calculated based on the sensing data.

[0130] Reference Fig.15A , the change amount of the actual degradation rate AD at low temperature may be smaller than the change amount of the degradation rate DR according to the degradation model DM0.

[0131] The accumulated degradation value ADV at time point t1 may be a first value V1. In this case, the degradation rate A converted from the first value V1 using the degradation model DM0 is different from the actual degradation rate B (e.g., sensed degradation rate) at time point t1. The sensed degradation value may be obtained by inversely converting the actual degradation rate B using the degradation model DM0, and the degradation value sensed at time point t1 may be a second value V2. The accumulated degradation value ADV at time point t1 may be corrected to a second value V2. In the degradation model DM0, the second value V2 represents a time point earlier than time point t1. Therefore, based on the first degradation model DM1 obtained by shifting the degradation model DM0 to the right on the time axis, the accumulated degradation value ADV may be later converted to a degradation rate DR so that the degradation model DM0 has a second value V2 at time point t1. The degradation model DM0 and the first degradation model DM1 are substantially the same.

[0132] The accumulated degradation value ADV at time point t2 may be a third value V3. In this case, the degradation rate C obtained when the third value V3 is converted into the degradation rate DR by using the first degradation model DM1 is different from the actual degradation rate D at time point t2. The sensed degradation value may be obtained by inversely converting the actual degradation rate D using the first degradation model DM1, and the degradation value sensed at time point t2 may be a fourth value V4. The accumulated degradation rate ADV at time point t2 may be corrected to a fourth value V4. In the first degradation model DM1, the fourth value V4 represents a time point earlier than time point t2. Therefore, based on the second degradation model DM2 obtained by shifting the first degradation model DM1 to the right on the time axis, the accumulated degradation value ADV may be converted into the degradation rate DR later, so that the first degradation model DM1 has a fourth value V4 at time point t2.

[0133] Reference Fig. 15B , the change amount of the actual degradation rate AD at high temperature may be greater than the change amount of the degradation rate DR according to the degradation model DM0.

[0134] The accumulated degradation rate ADV at time point t1 may be a first value V1. In this case, at time point t1, the degradation rate A converted from the first value V1 using the degradation model DM0 is different from the actual degradation rate B (e.g., the sensed degradation rate). The sensed degradation value may be obtained by inversely converting the actual degradation rate B using the degradation model DM0, and the degradation value sensed at time point t1 may be a second value V2. The accumulated degradation rate ADV at time point t1 may be corrected to a second value V2. In the degradation model DM0, the second value V2 represents a time point later than time point t1. Therefore, based on the first degradation model DM1 obtained by shifting the degradation model DM0 to the left on the time axis, the accumulated degradation value ADV may be later converted to a degradation rate DR so that the degradation model DM0 has a second value V2 at time point t1. The degradation model DM0 and the first degradation model DM1 are substantially the same.

[0135] The accumulated degradation value ADV at time point t2 may be a third value V3. In this case, the degradation rate C obtained when the third value V3 is converted into the degradation rate DR by using the first degradation model DM1 is different from the actual degradation rate D at time point t2. The sensed degradation value may be obtained by inversely converting the actual degradation rate D using the first degradation model DM1, and the degradation value sensed at time point t2 may be a fourth value V4. The accumulated degradation value ADV at time point t2 may be corrected to a fourth value V4. In the first degradation model DM1, the fourth value V4 represents a time point later than time point t2. Therefore, based on the second degradation model DM2 obtained by shifting the first degradation model DM1 to the left on the time axis, the accumulated degradation value ADV may be converted into the degradation rate DR later, so that the first degradation model DM1 has a fourth value V4 at time point t2.

[0136] Fig.16 is a flowchart of a data compensation method of a display device according to an exemplary embodiment of the inventive concept.

[0137] Reference Figure 2 and Fig.16 , the accumulator 212 may calculate and accumulate degradation values ​​of the plurality of pixel blocks (S310). For example, the accumulator 212 may calculate and accumulate degradation values ​​of each pixel block in the plurality of pixel blocks. As the calculated accumulated degradation values ​​are accumulated, an accumulated degradation value may be obtained, and the accumulator 212 may store the accumulated degradation value in the nonvolatile memory 213.

[0138] The sensing controller 214 may determine a sensing pixel block and a reference pixel block whose electrical characteristics are to be sensed based on the plurality of accumulated degradation values ​​of the plurality of pixel blocks (S320). The sensing controller 214 may determine at least one pixel block having a relatively high accumulated degradation value among the plurality of pixel blocks as a sensing pixel block, and Figure 1A dummy pixel block in the non-display area of ​​the display panel 20 or a pixel block having a reference degradation rate less than a reference value is determined as a reference pixel block. For example, a pixel block having a reference degradation rate may be determined to have no degradation. Figure 1 The sensing block 120 may sense (e.g., measure) electrical characteristics of the sensing pixel block and the reference pixel block under the control of the sensing controller 214 (S330). As described above, the sensing block 120 may sense at least one of various electrical characteristics. The sensing block 120 may provide sensing data indicating the sensed electrical characteristics to the corrector 215.

[0139] The corrector 215 may correct the accumulated degradation value of the sensing pixel block based on the first sensing data of the reference pixel block and the second sensing data of the sensing pixel block (S340). The corrector 215 may calculate a degradation rate (e.g., a sensing degradation value) by comparing the second sensing data of the sensing pixel block with the first sensing data indicating a state where the grayscale does not occur, so as to compensate for common variation factors such as noise due to the operation of the display panel 20, temperature, etc., and increase the accuracy of compensation. The corrector 215 may convert the sensing degradation value into a degradation value by using a degradation model, and correct the accumulated degradation value of the sensing pixel block based on the sensing degradation value SDV.

[0140] The data compensator 211 may perform data compensation on the plurality of pixel blocks based on the plurality of accumulated degradation values ​​(S350). In this case, the accumulated degradation values ​​of the sensing pixel blocks may be corrected accumulated degradation values.

[0141] After data compensation is performed, operations S310 to S350 may be repeatedly performed based on continuously received input data.

[0142] Fig.17 is a flowchart of a data compensation method of a display device according to another exemplary embodiment of the inventive concept.

[0143] Operations S410 to S430 and Figure 4 Operations S110 to S130 of FIG. 1 are substantially the same, and thus a description thereof will not be provided.

[0144] refer to Figure 2 and Fig.17 , the corrector 215 can be Figure 1The sensing block 120 of the data driver 100 receives the sensing data and calibrates the sensing data to correspond to the reference temperature (S440). The corrector 215 may receive the temperature of the sensing pixel block or temperature information for estimating the temperature of the sensing pixel block from the sensing block 120 or the display panel 20, and calibrate the sensing data to correspond to the reference temperature, thereby eliminating and / or reducing the influence caused by the temperature when performing sensing when the temperature of the sensing pixel block is different from the reference temperature. The corrector 215 may correct the accumulated degradation value of the sensing pixel block based on the calibrated sensing data (S450).

[0145] The data compensator 211 may perform data compensation on the plurality of pixel blocks based on the plurality of accumulated degradation values ​​and the temperature information (S460). The data compensator 211 may determine a compensation rate based on the degradation rate and compensate the input data based on the compensation rate, as described above with reference to Fig. 9 In this case, temperature compensation may be performed based on the temperature information so that a desired brightness at the reference temperature may be output at the current temperature.

[0146] Fig.18 A display device 1000 according to an exemplary embodiment of the inventive concept is shown. Fig.18 The display device 1000 is a device having a medium-to-large-sized display panel 1200 and can be applied to, for example, a television, a monitor, and the like.

[0147] Reference Fig.18 , the display device 1000 may include a data driver 1110 , a timing controller 1120 , a gate driver 1130 , and a display panel 1200 .

[0148] The timing controller 1120 may include one or more integrated circuits (ICs) or modules. The timing controller 1120 may communicate with a plurality of data drive ICs (DDICs) and a plurality of gate drive ICs (GDICs) according to a set interface.

[0149] The timing controller 1120 may generate a control signal for controlling driving timing of the plurality of DDICs and the plurality of GDICs, and provide the control signal to the plurality of DDICs and the plurality of GDICs.

[0150] The timing controller 1120 may divide the image data received from the outside into a plurality of pieces of image data and provide each piece of image data to one of the plurality of DDICs. In addition, the timing controller 1120 may perform data compensation on the received image data to compensate for pixel degradation. The timing controller 1120 may be as described above with reference to Figures 1 to 17As described, data compensation is performed based on the degradation model method using the accumulated degradation value, and the accumulated degradation value can be corrected based on the feature sensing method. Therefore, the consistency rate between the accumulated degradation value and the actual degradation rate can be increased to improve the brightness uniformity and reliability of the display panel 20.

[0151] The data driver 1110 includes a plurality of DDICs, which may be mounted on a circuit film such as TCP, COF, FPC, etc., and then attached to the display panel 1200 by a TAB method or mounted on a non-display area of ​​the display panel 1200 by a COG method.

[0152] At least one of the plurality of DDICs may include the above reference Figure 1 The sensing block 120 described above can sense electrical characteristics of the pixels and provide sensing data to the timing controller 1120.

[0153] The gate driver 1130 includes a plurality of GDICs. The plurality of GDICs may be mounted on a circuit film and attached to the display panel 1200 by a TAB method, or may be mounted on a non-display region of the display panel 1200 by a COG method. Alternatively, the gate driver 1130 may be formed directly on a lower substrate of the display panel 1200 by a gate driver IN panel (GIP) method. The gate driver 1130 is formed in a non-display region outside a pixel array of the display panel 1200 in which the pixel PX is formed, and may be formed by the same TFT process as the pixel PX.

[0154] Fig.19 A display device 2000 according to another exemplary embodiment of the inventive concept is illustrated. Fig.19 The display apparatus 2000 is a device having a small-sized display panel 2200 and can be applied to mobile devices such as smart phones, tablet PCs, etc.

[0155] Reference Fig.19 , the display device 2000 may include a display driving circuit 2100 and a display panel 2200. The display driving circuit 2100 may include one or more ICs and may be mounted on a circuit film such as TCP, COF, FPC, etc. and attached to the display panel 2200 by a TAB method, or mounted on a non-display area of ​​the display panel 2200 by a COG method.

[0156] The display driving circuit 2100 may include a data driver 2110 and a timing controller 2120 (also referred to as control logic), and may further include a gate driver. In an exemplary embodiment of the inventive concept, the gate driver may be mounted on the display panel 2200.

[0157] The timing controller 2120 may perform data compensation on image data received from an external device such as an application processor to compensate for pixel degradation. The timing controller 2120 may be as described above with reference to Figures 1 to 17 The accumulated degradation value is used to perform data compensation based on the degradation model method, and the accumulated degradation value can be corrected based on the feature sensing method. Therefore, the consistency between the accumulated degradation value and the actual degradation rate can be increased to improve the brightness uniformity and reliability of the display panel 2200.

[0158] In the sensing mode, the data driver 2110 may measure electrical characteristics of pixels of the display panel 2200, and provide sensing data indicating the measured electrical characteristics of the pixels to the timing controller 2120. The timing controller 2120 may correct the accumulated degradation value based on the measured electrical characteristics of the pixels. The timing controller 2120 may compensate the input data based on the accumulated degradation value, and provide the compensation data to the data driver 2110. The data driver 2110 may drive the display panel 2200 based on the compensation data.

[0159] While the inventive concept has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as set forth in the following claims.

Claims

1. A display driving circuit, comprising: a data driver configured to provide a driving signal to a plurality of pixels of the display panel and sense an electrical characteristic of each of the plurality of pixels; as well as a degradation compensation circuit configured to generate and store a plurality of accumulated degradation values ​​by accumulating the degradation value of each of the plurality of pixel blocks within a unit time based on driving data corresponding to the driving signal, correcting an accumulated degradation value of a first pixel block based on sensing data received from a data driver, and performing data compensation to compensate for pixel degradation based on the accumulated degradation value and the corrected accumulated degradation value, wherein each pixel block includes at least one pixel, Wherein, the degradation compensation circuit is further configured as follows: selecting a first pixel block from the plurality of pixel blocks for sensing, wherein the first pixel block includes at least one, but not all, pixel blocks having a relatively high accumulated degradation value among the plurality of accumulated degradation values, and Data compensation is performed on the first pixel block based on the corrected accumulated degradation value, and data compensation is performed on the pixel blocks other than the first pixel block among the plurality of pixel blocks based on the accumulated degradation values ​​thereof.

2. The display driving circuit according to claim 1, wherein: The degradation compensation circuit is also configured as: The data driver is controlled to sense the first pixel block according to a sensing period, and an accumulated degradation value of the first pixel block is corrected based on the sensing data.

3. The display driving circuit according to claim 2, wherein: After correcting the accumulated degradation value of the first pixel block, the degradation compensation circuit is further configured to: The degradation value calculated for the first pixel block in the next unit time is added to the corrected accumulated degradation value.

4. The display driving circuit according to claim 1, wherein: The degradation compensation circuit is also configured as: Each accumulated degradation value is converted into a degradation rate by using a degradation model, and input data of the pixel is compensated based on the degradation rate, wherein the degradation rate of each pixel represents a ratio of a current brightness of the pixel to an initial brightness of the pixel.

5. The display driving circuit according to claim 1, wherein: The degradation compensation circuit includes: an accumulator configured to generate a plurality of accumulated degradation values ​​for each of the plurality of pixel blocks and store the plurality of accumulated degradation values ​​in a non-volatile memory; a data compensator configured to convert the plurality of accumulated degradation values ​​into degradation rates based on a degradation model, and determine a brightness compensation rate of each of the plurality of pixel blocks based on a plurality of degradation rates corresponding to the plurality of pixel blocks; a sensing controller configured to select a first pixel block as a sensing pixel block based on the plurality of accumulated degradation values, and control a data driver to sense electrical characteristics of the sensing pixel block according to a sensing period; and A corrector is configured to correct the accumulated degradation value corresponding to the sensing pixel block based on the sensing data.

6. The display driving circuit according to claim 5, wherein: Sensor Controller selecting a reference pixel block based on the plurality of accumulated degradation values, and controlling a data driver to sense electrical characteristics of the reference pixel block and the sensing pixel block, and The corrector is further configured to calculate a sensing degradation rate corresponding to the sensing pixel block by comparing first sensing data corresponding to the reference pixel block with second sensing data corresponding to the sensing pixel block, and correct an accumulated degradation value corresponding to the sensing pixel block based on the sensing degradation rate.

7. The display driving circuit according to claim 6, wherein The sensing pixel block includes a pixel block having the highest accumulated degradation value among the plurality of accumulated degradation values, and the reference pixel block includes a dummy pixel block in a non-display area of ​​the display panel or a pixel block having the lowest accumulated degradation value among the plurality of accumulated degradation values.

8. The display driving circuit according to claim 5, wherein: The corrector is also configured to: The sensing data is calibrated to correspond to a reference temperature based on temperature sensing information about the sensing pixel block, and the accumulated degradation value corresponding to the sensing pixel block is corrected based on the calibrated sensing data.

9. The display driving circuit according to claim 5, wherein: The data compensator is also configured as: A brightness compensation rate of each of the plurality of pixel blocks is determined by comparing a reference degradation rate indicating a maximum brightness reduction or a minimum brightness reduction among the plurality of degradation rates with the remaining degradation rates among the plurality of degradation rates.

10. The display driving circuit according to claim 5, wherein: The accumulator is also configured as: Driving data corresponding to the driving signal is generated by applying a brightness or gamma characteristic set for the compensated input data of each of the plurality of pixel blocks, and a degradation value is generated and accumulated for each frame or at predetermined time intervals based on the driving data.

11. The display driving circuit according to claim 5, wherein: The accumulator is also configured as: Grayscale data of each of the plurality of pixel blocks is generated and accumulated for each frame or at predetermined time intervals based on the compensated input data.

12. The display driving circuit according to claim 1, wherein: The sensing data includes a threshold voltage of a driving transistor of a pixel to be sensed, a difference in potential between a first terminal and a second terminal of a light emitting element of the pixel, or a current flowing through the light emitting element.

13. The display driving circuit according to claim 1, wherein: Each of the plurality of pixels includes an organic light emitting element.

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