Organic light emitting display device

Abstract

The present disclosure provides an organic light-emitting display device, which includes a data driver that supplies a data voltage to a data line of each sub-pixel, senses a driving voltage of each sub-pixel through each sensing line connected to the sub-pixel, and generates sensing data based on the driving voltage of each sub-pixel. In addition, the organic light-emitting display device includes a controller that uses the sensing data generated from the data driver to generate a reference parameter for compensating each operating characteristic of each sub-pixel, and the controller compensates image data based on the reference parameter and outputs the compensated image data. The controller controls the gate driver and the data driver to additionally generate sensing data, and compensates and outputs the image data based on the compensation parameter, which is extracted based on the additionally generated sensing data, thereby controlling the execution of external compensation based on temperature and degradation characteristics.

Description

Technical Field

[0001] The present disclosure relates to an organic light emitting display device, and more particularly, to an organic light emitting display device that can perform external compensation on degradation characteristics while excluding temporary variable influences at the time of degradation characteristic detection, thereby increasing detection accuracy and external compensation efficiency. Background Art

[0002] Image display devices that display various information on a screen are key technologies in the current information communication era, and are being developed to provide thinner, lighter, portable, and high-performance devices.

[0003] In particular, organic light-emitting display devices in image display devices have advantages in power consumption due to low operating voltage, and organic light-emitting display devices have high response speed, high luminous efficiency, larger viewing angle, and excellent contrast, and therefore have received increasing attention as color display mechanisms.

[0004] The organic light emitting display device uses a plurality of sub-pixels arranged in a matrix to present an image. Each of the plurality of sub-pixels includes an organic light emitting element, and a switching thin film transistor (TFT) configured to independently drive the organic light emitting element, a driving TFT, and a storage capacitor.

[0005] The switching TFT of each sub-pixel is turned on in response to a scan signal from the gate line. During its on period, the switching TFT supplies a data voltage from the data line to the gate electrode of the driving TFT and the storage capacitor.

[0006] The driving TFT of each sub-pixel controls the current flowing through the organic light emitting element based on the difference between the voltages of its gate electrode and source electrode.

[0007] The organic light emitting element is connected to and arranged between the source electrode of the driving TFT and the low potential driving voltage source. Therefore, the brightness of each sub-pixel is proportional to the current flowing through the organic light emitting element. The current flowing through the organic light emitting element depends on the difference between the gate voltage and the source voltage of the driving TFT, the threshold voltage Vth of the driving TFT and its mobility.

[0008] Generally, non-uniformity in brightness between sub-pixels in an organic light emitting display device may be caused by differences between electrical characteristics including a threshold voltage and mobility of a driving TFT.

[0009] One of the reasons for the difference in electrical characteristics between the driving TFTs of the sub-pixels may be that the amounts of degradation that occur in the driving TFTs of the sub-pixels during panel operation are different from each other.

[0010] Therefore, a method for sensing the mobility and the threshold voltage Vth of the driving TFT of the sub-pixel and compensating for the difference therebetween has been proposed to minimize the difference between the electrical characteristics of the driving TFT of the sub-pixel. Summary of the invention

[0011] Conventionally, compensation is performed based on the difference between the mobility of the driving TFTs of the sub-pixels and the difference between the threshold voltages sensed in the panel manufacturing environment. Therefore, in the actual use state of commercialization, additional characteristic differences may occur due to the use environment and the use period. Therefore, the non-uniformity between the brightness of the sub-pixels is inevitable.

[0012] In order to compensate for the characteristic difference in the commercial state, the mobility and threshold voltage of the driving TFT of the sub-pixel should be sensed in the actual use state. However, the sensing accuracy of the difference and its compensation efficiency may inevitably decrease because the influence on the difference may be temporarily variable based on the use environment and operation period.

[0013] To solve the above-mentioned problems and other problems associated with the prior art, an object of the present disclosure is to provide an organic light-emitting display device that is capable of measuring the mobility and threshold voltage of a driving TFT of each sub-pixel, thereby eliminating the influence of temporary variables and allowing external compensation based on temperature and degradation characteristics.

[0014] In addition, another object of the present disclosure is to provide an organic light-emitting display device that is capable of compensating for differences in mobility and differences in threshold voltages of driving TFTs of sub-pixels based on temperature and degradation characteristics in a commercial state, and is capable of performing external compensation so that the compensated mobility and threshold voltage characteristics of each driving TFT are similar to the mobility and threshold voltage characteristics measured during panel manufacturing to the greatest extent.

[0015] The purpose according to the present disclosure is not limited to the above-mentioned purpose. Other unmentioned purposes and advantages according to the present disclosure can be understood based on the following description, and can be more clearly understood based on the embodiments according to the present disclosure. In addition, it will be easily understood that the purposes and advantages according to the present disclosure can be achieved using the mechanisms shown in the claims and their combinations.

[0016] An organic light-emitting display device according to an embodiment of the present disclosure includes a data driver that supplies a data voltage to a data line of each sub-pixel, senses a driving voltage of each sub-pixel through each of a plurality of sensing lines connected to each of the sub-pixels, and generates sensing data based on the driving voltage of each sub-pixel.

[0017] In addition, the organic light emitting display device may include a controller that generates a reference parameter for compensating each of the operating characteristics of each sub-pixel using sensing data generated from the data driver, compensates image data based on the reference parameter, and outputs the compensated image data.

[0018] The controller may control the gate driver and the data driver so that sensing data may be additionally generated, and compensate and output the image data based on the compensation parameter extracted based on the additionally generated sensing data.

[0019] In addition, the display panel of the organic light-emitting display device according to an embodiment of the present disclosure includes a sub-pixel, which includes: a switching transistor, which supplies a data voltage for detection from each data line to a first node in response to a scan signal of each gate line; a storage capacitor for charging and discharging the data voltage supplied to the first node; a driving transistor, which is used to supply a high potential voltage to an organic light-emitting element of a second node based on the amplitude of the data voltage of the first node; and a sensing transistor, which transmits a driving voltage outputted from the driving transistor to the second node to a sensing line in response to a sensing control signal.

[0020] According to an embodiment of the present disclosure, the organic light-emitting display device can measure the mobility and threshold voltage of the driving TFT of each sub-pixel, thereby eliminating the influence of temporary variables, and the organic light-emitting display device can compensate for the differences between the operating characteristics of the driving TFTs of the sub-pixels, such as mobility and threshold voltage, thereby improving detection accuracy and external compensation efficiency.

[0021] In addition, the organic light-emitting display device can compensate for the difference between the mobility and the difference between the threshold voltage of the driving TFT of the sub-pixel based on the temperature and degradation characteristics under commercial and actual use conditions, and can perform external compensation so that the compensated mobility and threshold voltage characteristics of each driving TFT are similar to the mobility and threshold voltage characteristics measured during panel manufacturing to the greatest extent. Therefore, the operating characteristics of the organic light-emitting element can be further improved.

[0022] In addition, specifically, for external compensation in a commercial state, compensation parameters can be calculated to be as similar as possible to reference parameters set for external compensation during panel manufacturing, and then external compensation can be performed based on the compensation parameters. Therefore, the external compensation efficiency can be further improved.

[0023] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present disclosure will become more fully understood through the detailed description and accompanying drawings given below, which are given by way of illustration only and thus do not limit the present disclosure.

[0025] Figure 1 is a block diagram schematically illustrating an organic light emitting display device according to an embodiment of the present disclosure.

[0026] Figure 2 It is shown that the Figure 1 An exemplary diagram of an arrangement structure of unit pixels and sub-pixels in a display panel of FIG.

[0027] Figure 3 It specifically shows Figure 1 and Figure 2 Circuit diagram of the sub-pixel structure shown.

[0028] Figure 4 It is shown in detail Figure 1 Block diagram of the controller shown in .

[0029] Figure 5 It is shown in detail Figure 1 A block diagram of a data driver is shown.

[0030] Figure 6 is a flowchart illustrating a method for performing external compensation of an organic light emitting display device according to an embodiment of the present disclosure.

[0031] Figure 7 1 is a timing chart for illustrating a mobility and threshold voltage measurement process in a product manufacturing step according to an embodiment of the present disclosure.

[0032] Figure 8 is a timing diagram for illustrating a mobility and threshold voltage measurement process in an actual use stage according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] For the sake of simplicity and clarity of illustration, the elements in the drawings are not necessarily drawn to scale. The shapes, sizes, ratios, angles, quantities, etc. disclosed in the drawings for describing the embodiments of the present disclosure are exemplary, and the present disclosure is not limited thereto. The same reference numerals refer to the same elements in this article. The same reference numerals in different drawings represent the same or similar elements, and therefore perform similar functions. In addition, for the sake of simplicity of description, the description and details of the known steps and elements are omitted. In addition, in the following detailed description of the present disclosure, many specific details are set forth to provide a thorough understanding of the present disclosure. However, it should be understood that the present disclosure can be practiced without these specific details. In other examples, known methods, processes, components and circuits are not described in detail to avoid making it unnecessarily difficult to understand the various aspects of the present disclosure.

[0034] Examples of various embodiments are further shown and described below. It should be understood that the description herein is not intended to limit the claims to the specific embodiments described. On the contrary, it is intended to cover alternatives, modifications and equivalents that may be within the spirit and scope of the present disclosure defined by the appended claims.

[0035] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the present disclosure. As used herein, the terms "one" and "said" are intended to include singular and plural forms, unless the context clearly indicates otherwise. It will be further understood that when used in this specification, the terms "comprising", "including" and "having" specify the presence of the features, integers, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, operations, elements, parts and / or parts thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Expressions such as "at least one of" may modify the entirety of the element list when before the element list, and may not modify the individual elements of the list. When referring to "C to D", unless otherwise stated, this means C to D and includes C and D.

[0036] It should be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Therefore, without departing from the spirit and scope of the present disclosure, the first element, component, region, layer or section described below may be referred to as a second element, component, region, layer or section.

[0037] It will be understood that when an element or layer is referred to as being “connected to” or “coupled to” another element or layer, it can be directly on, connected to or coupled to the other element or layer, or one or more intervening elements or layers may be present. Additionally, it will be understood that when an element or layer is referred to as being “between” two elements or layers, it can be the only element or layer between the two elements or layers, or one or more intervening elements or layers may also be present.

[0038] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which the inventive concept belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0039] The features of various embodiments of the present disclosure may be partially or completely combined with each other, and may be technically related to each other or operate with each other. The embodiments may be implemented independently of each other, and may be implemented together in a related relationship.

[0040] In interpreting numerical values ​​in the present disclosure, a range of error may be inherent even if not expressly stated individually.

[0041] In the description of a signal flow relationship, for example, when a signal is transmitted from node A to node B, the signal may be transmitted from node A to node B via node C unless an indication that the signal is transmitted directly from node A to node B is specified.

[0042] Hereinafter, an organic light emitting display device according to one or more embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. All components of each organic light emitting display device according to all embodiments of the present disclosure are operatively coupled and configured.

[0043] Figure 1 is a block diagram schematically showing an organic light emitting display device according to an embodiment of the present disclosure. In addition, Figure 2 It is shown that the Figure 1 An exemplary diagram of an arrangement structure of unit pixels and sub-pixels in a display panel of FIG.

[0044] Reference Figure and Figure 2 The organic light emitting display device includes a display panel 100 , a gate driver 200 , a data driver 300 , a controller 400 , and a storage device 500 .

[0045] In the display panel 100, the sub-pixels P are arranged in a matrix form and are respectively disposed at intersections between a plurality of gate lines GL1 to GLi and a plurality of data lines DL1 to DLn, wherein i and n may be positive numbers, such as positive integers. Each sub-pixel P receives a high potential driving voltage EVDD and a low potential driving voltage VSS, and is connected to each of the gate lines GL1 to GLi and each of the data lines DL1 to DLn.

[0046] refer to Figure 2 , one unit pixel 110 may be composed of at least three or four sub-pixels R, G, B, and W. An example in which four sub-pixels R, G, B, and W of red, green, blue, and white constitute one unit pixel 110 will be described below. In this regard, Figure 2 An example is shown in which two unit pixels 110 are shown, each unit pixel 110 is composed of four sub-pixels R, G, B, W of red, green, blue and white. A plurality of such unit pixels 110 can be used Figure 1 in the display device.

[0047] Each of the four sub-pixels R, G, B, and W constituting each unit pixel 110 may be connected to each sensing line because each of the data lines DL1 to DLn is connected to each sub-pixel. However, in this case, the formation area of ​​each sub-pixel P may be narrowed, and thus the display efficiency may be reduced. Therefore, as Figure 2 As shown, the four sub-pixels R, G, B, and W constituting each unit pixel 110 may be connected in common to a single sensing line SL. When n data lines DL1 to DLn are formed in the display panel 100, the total number (m) of sensing lines SL1 to SLm is n / 4. At this point, each of n and i is a natural number other than 0. Therefore, m is a natural number other than 0, which is 1 / 4 of n.

[0048] Figure 3 It specifically shows Figure 1 and Figure 2 Circuit diagram of the sub-pixel structure shown.

[0049] Figure 3 The sub-pixel P structure as a 2T (transistor) 1C (capacitor) structure including a switching transistor ST1, a driving transistor DT, a storage capacitor Cst, and an organic light emitting element OLED is shown. The sub-pixel P structure can be embodied as a structure in which a transistor and a capacitor are added in addition to the 2T1C structure. Hereinafter, the 2T1C structure will be described by way of example.

[0050] refer to Figure 3 Each sub-pixel P may further include a sensing transistor ST2 configured to sense the mobility and the threshold voltage Vth of the driving transistor DT and disposed between the output of the driving transistor DT and the sensing line SL.

[0051] In addition, each sub-pixel P may also include: an initialization switching element SWl, which applies a sensing initialization voltage Vpres to each sensing transistor ST2 during a period for detecting the operating characteristics of the driving transistor DT; an enabling switching element SW2, which applies a display enabling voltage Vprer to each sensing transistor ST2 during an image display period of each sub-pixel P; and a line switching element SW3, which connects each sensing line SL to the data driver 300 when detecting the operating characteristics of the driving transistor DT.

[0052] The detailed configuration of the sub-pixel P and its operational characteristics according to an embodiment of the present disclosure are described in more detail as follows.

[0053] The switching transistor ST1 may have a gate connected to a gate line GL supplied with a scan signal SCAN among gate signals, a source connected to a data line DL supplied with a data voltage Vdata, and a drain connected to a first node N1 connected to the gate of the driving transistor DT. Therefore, the switching transistor ST1 transmits the data voltage Vdata to the first node N1 during the image display period in response to the scan signal SCAN. Conversely, during a period for detecting the operating characteristics of the driving transistor DT (e.g., its mobility and threshold voltage), the switching transistor ST1 may supply the first or second data voltage Vata_1 or Vata_2 from the data driver 300 to the first node N1 for detection.

[0054] The driving transistor DT has a gate connected to the first node N1, a source connected to the first power line VL supplied with a high potential voltage EVDD, and a drain connected to the second node N2 electrically connected to the organic light emitting element OLED. Therefore, during the image display period, the driving transistor DT is activated based on the magnitude of the data voltage Vdata of the storage capacitor Cst and the first node N1. In addition, during the period for detecting the operating characteristics of the driving transistor DT, the driving transistor DT is activated based on the first or second data voltage Vata_1 or Vata_2.

[0055] The organic light emitting element OLED has an anode connected to the second node N2 which is the drain (output) of the driving transistor DT, and a cathode connected to the second power line to which the low potential voltage EVSS is supplied.

[0056] The sensing transistor ST2 has a gate connected to a sensing control signal input line CL to which a sensing control signal SEM among gate signals is supplied, a source connected to a second node N2 which is a drain (output) of the driving transistor DT, and a drain connected to the sensing line SL. Therefore, the sensing transistor ST2 transmits a driving voltage output to the drain (e.g., the second node N2) of the driving transistor DT to the sensing line SL in response to the sensing control signal SEM input during a period for detecting the operating characteristics of the driving transistor DT.

[0057] like Figure 2 and Figure 3 As shown, four sub-pixels R, G, B, and W may be connected to each of the sensing lines SL1 to SLm. Therefore, each switch structure for applying a sensing initialization voltage Vpres or a display enable voltage Vprer to each sub-pixel P may be further included.

[0058] Specifically, the initialization switching element SW1 applies a sensing initialization voltage Vpres to the sensing line SL and the sensing transistor ST2 in response to the initialization control signal SPRE. The sensing initialization voltage Vpres is input from the gate driver 200 to the initialization switching element SW1 during an initialization period for detecting operating characteristics of the driving transistor DT in each of the subpixels P in the corresponding line.

[0059] The enabling switch element SW2 is turned on in response to the enabling control signal PPRE, so that the display enabling voltage Vprer is applied to the sensing line SL and the sensing transistor ST2. During the non-detection period of the operating characteristics of the sub-pixels P in the corresponding line displaying an image, the enabling control signal PPRE is input to the enabling switch element SW2 from the gate driver 200 or the like.

[0060] The line switch element SW3 connects each of the sensing lines SL1 to SLm to the data driver 300 or the converter ADC of the data driver 300, or disconnects each of the sensing lines SL1 to SLm from the data driver 300 or the converter ADC of the data driver 300 in response to a sampling signal SAM input from the gate driver 200 or the like. During an image display period of each sub-pixel P, the sampling signal SAM may be supplied to the line switch element SW3 to disconnect each of the sensing lines SL1 to SLm from the data driver 300 or the converter ADC of the data driver 300, and during a driving voltage sensing period of each sub-pixel P, the sampling signal SAM may be input to the line switch element SW3 to connect each of the sensing lines SL1 to SLm to the data driver 300 or the converter ADC of the data driver 300.

[0061] During a period for sensing the mobility of the driving transistor DT and its threshold voltage Vth, the sub-pixel P as described above may operate as follows.

[0062] First, when a scan signal SCAN is supplied to each sub-pixel through each gate line GL, the switch transistor ST1 is turned on in response to the scan signal SCAN. At this time, a first data voltage Vdata_1 for detection is supplied to the data line DL, and the amplitude of the first data voltage Vdata_1 is predefined to facilitate sensing the operating characteristics of the driving transistor DT.

[0063] Therefore, when the first data voltage Vdata_1 for detection is supplied to the first node N1 through the turned-on switching transistor ST1, the driving transistor DT is activated based on the amplitude of the first data voltage Vdata_1 for detection. At this time, the sensing control signal SEN is supplied to the gate of the sensing transistor ST2, turning on the sensing transistor ST2.

[0064] Subsequently, when the line switch element SW3 is turned on based on the sampling signal SAM, the driving voltage of the driving transistor DT is transmitted to the data driver 300 through the sensing transistor ST2 and the sensing line SL. In this regard, the amplitude of the driving voltage may fluctuate or change in real time based on the degradation characteristics of the driving transistor DT during the period in which each driving transistor DT is activated. Therefore, the voltage between the gate and the source of the driving transistor DT may be maintained at a level higher than the threshold voltage of the driving transistor DT during a predetermined period, and then a driving voltage sensing path may be formed through the sensing transistor ST2, the sensing line SL, and the line switch element SW3.

[0065] As described above, after the voltage between the gate and source of the driving transistor DT is maintained at a level higher than the threshold voltage of the driving transistor DT for a predetermined period of time, or after the voltage between the gate and source of the driving transistor DT and the threshold voltage of the driving transistor DT are equal to each other, the driving voltage of each driving transistor DT can be sensed. Therefore, the influence based on the mobility change of each driving transistor DT can be eliminated. In other words, although the mobility of each driving transistor DT can continue to change during the time period when each driving transistor DT is activated, the voltage between the gate and source of the driving transistor DT can be changed to rise to and maintained at the threshold voltage. Therefore, when stabilizing the driving voltage of each driving transistor DT, the influence based on the mobility change can be eliminated and excluded.

[0066] The voltage detection process for detecting the operating characteristics of the driving transistor DT in each sub-pixel P is performed only when the compensation parameters for compensating the difference between the mobilities and the difference between the threshold voltages of the driving transistors DT of the sub-pixels P are generated. In one example, in the manufacturing process of the organic light emitting display device, the reference mobility difference and the reference threshold voltage difference may be detected first, and then the reference parameters for compensating each of the reference mobility difference and the threshold voltage may be set and stored.

[0067] During the actual use period after the organic light emitting display device is commercialized, the mobility and threshold voltage of the driving transistor DT of each sub-pixel P may be sensed in response to a user's control command or a pre-programmed control command (e.g., in a power-off operation). Therefore, additional compensation parameters may be created based on the sensed mobility and threshold voltage, and may then be applied to external compensation.

[0068] For example, in order to additionally generate or update compensation parameters when the power is turned off, the gate driver 200 sequentially generates a scan signal SCAN in response to the gate control signal GCS. In addition, the scan signal SCAN is sequentially transmitted to the plurality of gate lines GL1 to GLi. Therefore, the scan signal SCAN is supplied to each sub-pixel P.

[0069] Furthermore, the gate driver 200 individually supplies a sensing control signal SEN to the sensing transistor ST2 of each sub-pixel P in response to the gate control signal GCS from the controller 400 .

[0070] On the other hand, the data driver 300 additionally supplies a second data voltage Vdata_2 for detection to each of the sub-pixels P through the plurality of data lines DL1 to DLn in response to the data control signal DCS. In addition, the data driver 300 senses a driving voltage of each sub-pixel P input through each of the sensing lines SL1 to SLm during a specific blank period, converts the sensed driving voltage into digital sensing data Sdata', and stores the digital sensing data Sdata' in the storage device 500.

[0071] Next, the controller 400 receives the sensing data Sdata' additionally detected and generated by the data driver 300 from the storage device 500, compares the additionally detected sensing data Sdata' with each other, and then creates and stores the compensation parameter based on the comparison result. In addition, when the image data RGB from the external system is input to the controller 400, the controller 400 adds the additionally generated compensation parameter value to the image data RGB or multiplies the image data RGB by the additionally generated compensation parameter value, and generates and outputs the compensated image data R'G'B'.

[0072] The controller 400 may create additional compensation parameters that are as similar as possible to the reference parameters set when manufacturing the organic light-emitting display device. To this end, the controller 400 may compare the additionally detected and generated sensing data Sdata' with the sensing data Sdata detected during the product manufacturing process, and generate and use compensation parameters so that the comparison difference between them can be minimized. The compensation parameter generation method will be described in more detail later with reference to the accompanying drawings.

[0073] Figure 4 It is shown in detail Figure 1 The block diagram of the controller is shown.

[0074] refer to Figure 4 , based on the type of device where the controller 400 is installed, the controller 400 may be configured to be combined with various processors such as a microprocessor, a mobile processor, an application processor, etc. The controller 400 includes an external compensator 410, a control signal generator 420, a data alignment module 430, and a data output module 440.

[0075] Specifically, the external compensator 410 compares and analyzes the sensing data Sdata and Sdata' detected using the data driver 300, and creates a reference parameter and a compensation parameter for compensating for the difference between the mobility and the difference between the threshold voltages of the driving transistors DT of the sub-pixels P based on the comparison and analysis results. For reference, the compensation parameter for compensating for the difference between the mobility and the difference between the threshold voltages of the driving transistors DT can be calculated using an equation or method proposed in Korean Patent No. 10-1887238 (2018.08.03) owned by the present applicant. The patent document is incorporated herein by reference.

[0076] The external compensator 410 receives the image data RGB from an external system or the like, and compensates the image data of each sub-pixel P by applying a compensation value based on a reference parameter or a compensation value based on a compensation parameter to the input image data RGB.

[0077] In particular, the external compensator 410 may generate and use compensation parameters so that the difference between the sensing data Sdata detected during the product manufacturing process and the sensing data Sdata' detected additionally may be minimized. In this case, the compensation parameters may be set by sequentially updating the compensation parameters so that the sensing data Sdata' detected additionally may be detected in a state most similar to the sensing data Sdata detected during the product manufacturing process. Therefore, the external compensator 410 performs external compensation step by step so that the difference based on temperature and degradation characteristics occurring in the commercial state may be minimized, and the mobility and threshold voltage of each driving TFT may be as close as possible to the mobility and threshold voltage of each driving TFT measured during the panel manufacturing process.

[0078] The control signal generator 420 generates a gate control signal GCS and a data control signal DCS for image display during an image display period, and transmits them to the gate driver 200 and the data driver 300. In addition, according to a control command after the device is commercialized, the control signal generator 420 generates a gate control signal GCS and a data control signal DCS for sensing the mobility and threshold voltage of the driving transistor DT of each sub-pixel P during an image non-display period, and transmits them to the gate driver 200 and the data driver 300.

[0079] The data alignment module 430 aligns compensated image data R′G′B′ generated by applying reference parameters or compensation parameters to the input image data RGB according to characteristics such as the resolution and operating frequency of the display panel 100 .

[0080] The data output module 440 outputs the compensated image data R′G′B′ aligned based on the resolution of the display panel 100 to the data driver 300 on at least one horizontal line basis according to the operating frequency of the display panel 100 .

[0081] Figure 5 It is shown in detail Figure 1 A block diagram of a data driver is shown.

[0082] refer to Figure 5 , the data driver 300 includes a data voltage output module 310 and a driving voltage sensing module 320 .

[0083] The data voltage output module 310 converts the compensated image data R′G′B′ from the controller 400 into analog data voltages Vdata, and sequentially supplies the converted analog data voltages Vdata to each of the data lines DL1 to DLn.

[0084] The driving voltage sensing module 320 senses the driving voltage input to each sub-pixel P through each of the sensing lines SL1 to SLm during the image non-display period, converts the sensed driving voltage into digital sensing data Sdata, and transmits the digital sensing data Sdata to the storage device 500.

[0085] Figure 6 is a flowchart illustrating a method for performing external compensation of an organic light emitting display device according to an embodiment of the present disclosure.

[0086] A detailed description of the compensation parameter generation and external compensation process of the controller 400 is as follows.

[0087] refer to Figure 6 In the process of manufacturing and inspecting the organic light emitting display device, a reference parameter for compensating for each difference between the mobility and the threshold voltage Vth of the driving transistor DT of the sub-pixel P may be generated using a probe unit or the like.

[0088] In this regard, the inspection device such as the probe unit may supply a scan signal SCAN to the switching transistor ST1 of each sub-pixel P and supply a first data voltage Vdata_1 for detection to each data line DL, thereby sensing the driving voltage of each driving transistor DT through the sensing transistor ST2 and the sensing line SL. In addition, the controller 400 may generate a reference parameter (SS11) based on the comparison and analysis results of the sensing data Sdata.

[0089] Then, the organic light emitting display device may compensate image data RGB input from an external system using the compensation value based on the reference parameter after the device is commercialized, and may display an image corresponding to the compensated image data on the display panel 100 (SS12).

[0090] When the organic light emitting display device is in a commercialized and actually used state, the mobility and threshold voltage of the driving transistor DT of each sub-pixel P may be re-sensed based on a user's control command or a pre-programmed control command. Then, a compensation parameter may be calculated based on the re-sensed mobility and threshold voltage, and then the compensation parameter may be applied to external compensation.

[0091] To this end, the controller 400 generates gate and data control signals GCS and DCS during the image non-display period, and transmits the gate and data control signals GCS and DCS to the gate and data drivers 200 and 300, respectively. Therefore, the mobility and threshold voltage of the driving transistor DT of each sub-pixel P can be sensed (SS21). In addition, the controller 400 can compare and analyze the sensing data Sdata' additionally detected and generated using the data driver 300, and generate and store the compensation parameter based on the comparison and analysis results (SS22).

[0092] Then, depending on the setting, image data RGB is input from an external system, and the image data of each sub-pixel P can be compensated by adding the additionally generated compensation parameter value to the image data of each sub-pixel P or multiplying the image data of each sub-pixel P by the additionally generated compensation parameter value (SS23).

[0093] In one example, the controller 400 may update and generate compensation parameters so that the difference between the sensing data Sdata detected during the product manufacturing process and the sensing data Sdata' additionally detected during actual use of the device can be minimized. In this case, the controller 400 may generate and set the compensation parameters by gradually updating the compensation parameters so that the additionally detected sensing data Sdata' is gradually more similar to the sensing data Sdata detected during the product manufacturing process (SS31).

[0094] In addition, the external compensator 410 included in the controller 400 can compensate for the difference based on the temperature and degradation characteristics occurring in the commercialization and actual use state of the device, and can perform external compensation while gradually updating the compensation parameters, so that the mobility and threshold voltage of each driving TFT in the commercialization and actual use state of the device can be gradually made as similar as possible to the mobility and threshold voltage of each driving TFT measured during the panel manufacturing process (SS32).

[0095] Figure 7is a timing diagram for illustrating a mobility and threshold voltage measurement process in a product manufacturing process according to an embodiment of the present disclosure.

[0096] refer to Figure 7 In the process of manufacturing and commercializing an organic light emitting display device, a reference parameter for compensating for a difference between operating characteristics of the sub-pixels P may be first set during a device inspection process using an automatic probe unit or the like.

[0097] An operation period of each sub-pixel for sensing the mobility and threshold voltage Vth of each driving transistor DT of each sub-pixel P may be divided into an initialization period T1, a programming period T2, a driving voltage maintaining period T3, and a sensing period T4.

[0098] refer to Figure 3 and Figure 7 , within the initialization period T1 for sensing the mobility and threshold voltage Vth of the driving transistor DT in the operation period of each subpixel P, the switching transistor ST1 and the driving transistor DT are maintained in the off state, and the sensing initialization voltage Vpres is applied to the sensing transistor ST2 and the sensing line SL.

[0099] In the programming period T2 , the scan signal SCAN is supplied to the switching transistor ST1 through the gate line GL, and the first data voltage Vdata_1 for detection predefined in the turn-on period of the switching transistor ST1 is supplied to the data line DL.

[0100] During the driving voltage maintaining period T3 , the sensing control signal SEN is supplied to the sensing transistor ST2 to turn on the sensing transistor ST2 . Thus, the driving voltage (output voltage of the driving transistor DT) activated in a manner corresponding to the magnitude of the first data voltage Vdata_1 for detection is detected through the sensing line SL.

[0101] In the sensing period T4, the line switch element SW3 is turned on in response to the sampling signal SAM. Therefore, the driving voltage of the driving transistor DT is transmitted to the data driver 300 through the sensing transistor ST2 and the sensing line SL. In addition, when the line switch element SW3 is turned off, the display enable voltage Vprer is applied to the sensing transistor ST2 and the sensing line SL to reset the sensing transistor ST2 and the sensing line SL.

[0102] In one example, in the process of detecting the mobility and threshold voltage of the driving transistor DT of each sub-pixel P to set the reference parameters, the low potential voltage of the low potential voltage source EVSS connected to the cathode of the organic light emitting element OLED may be increased to a voltage level higher than 0V, so that a voltage of at least 0V may be applied to the cathode of the organic light emitting element OLED. When the low potential voltage applied to the cathode of the organic light emitting element OLED is increased, the mobility and threshold voltage detection timing and accuracy of the driving transistor DT may be improved.

[0103] Figure 8 is a timing diagram for illustrating a mobility and threshold voltage measurement process in an actual use stage of a device according to an embodiment of the present disclosure.

[0104] In order to compensate for the difference between the operating characteristics of the sub-pixels P when the organic light-emitting display device is actually used in a commercialized state, the reference parameters must be updated, for example, compensation parameters different from the reference parameters must be additionally created. To this end, the mobility and threshold voltage of each driving transistor DT must be repeatedly sensed in an actual use state, so that the compensation parameters can be repeatedly updated and applied to external compensation.

[0105] refer to Figure 8 , the operation period for sensing the mobility and threshold voltage of the driving transistor DT of each sub-pixel P under actual use can be divided into an enabling period TT1, a degradation maintenance period TT2, a driving voltage change maintenance period TT3_1, a driving voltage output control period TT3_2 and a driving voltage sensing period T4.

[0106] During the enabling period TT1, the scan signal SCAN may be supplied to the switching transistor ST1, and at the same time, the sensing control signal SEN may be supplied to the sensing transistor ST2 to turn on both the switching transistor ST1 and the sensing transistor ST2.

[0107] In this regard, the sensing initialization voltage Vpres may be applied to the sensing transistor ST2 and the sensing line SL. The predefined second data voltage Vdata_2 for detection is applied to the storage capacitor Cst through the switching transistor ST1.

[0108] In the degradation maintaining period TT2, the switching transistor ST1 is maintained in the on state and the sensing transistor ST2 is turned off. Therefore, the driving transistor DT is activated based on the voltage charged by the storage capacitor Cst, so that the driving transistor DT is maintained in the degradation state.

[0109] When the sensing transistor ST2 is turned off during the degradation maintenance period TT2, the driving transistor DT is activated based on the voltage charged by the storage capacitor Cst, thereby increasing the gate-source voltage of the driving transistor DT. At this time, the gate-source voltage of the driving transistor DT increases in response to the degradation amount of the organic light emitting element OLED. Therefore, the present method can detect the driving voltage of the driving transistor DT in a more accurate manner based on the degradation amount of the organic light emitting element OLED and the driving transistor DT.

[0110] During the driving voltage variation period TT3_1, the sensing control signal SEN may be supplied to the sensing transistor ST2 to turn on the sensing transistor ST2. Since the sensing transistor ST2 is turned on, the driving current of the driving transistor DT flows to the sensing transistor ST2, so that the amplitude of the driving voltage of the driving transistor DT fluctuates or varies in real time.

[0111] Although the magnitude of the driving voltage of the driving transistor DT fluctuates or changes in real time based on the degradation characteristics of the driving transistor DT, the gate-source voltage of the driving transistor DT is maintained at a level higher than the level of the threshold voltage of the driving transistor DT based on the voltage at which the storage capacitor Cst is charged. Therefore, the driving voltage of the driving transistor DT is very slowly reduced or maintained in a stable state based on the voltage at which the storage capacitor Cst is charged.

[0112] In the driving voltage output control period TT3_2, the gate-source voltage of the driving transistor DT is maintained at a level higher than the threshold voltage level of the driving transistor DT. Therefore, in the period in which the driving transistor DT outputs the driving voltage, the driving voltage of the driving transistor DT is applied to the sensing transistor ST2.

[0113] The mobility of each driving transistor DT can be continuously changed within the period in which each driving transistor DT is activated. However, even when the mobility of each driving transistor DT changes, the gate-source voltage of the driving transistor DT can only be changed to rise to the threshold voltage and maintained at the threshold voltage. Therefore, the influence of the mobility change of each driving transistor DT can be eliminated and excluded.

[0114] In the driving voltage sensing period TT4, the present scheme may first turn off the sensing transistor ST2, and then may supply the sampling signal SAM to the line switching element SW3 to electrically connect each of the sensing lines SL1 to SLm to the data driver 300. Therefore, the driving voltage of each driving transistor DT applied to each of the sensing lines SL1 to SLm is transmitted to the data driver 300.

[0115] As such, the organic light emitting display device according to the present disclosure excludes temporary variable influences when measuring the mobility and threshold voltage of the driving transistor DT, and compensates for differences between operating characteristics of the driving transistor DT based on the measurement, thereby improving external compensation efficiency and accuracy.

[0116] In addition, the controller 400 repeats the sensing process to update and generate compensation parameters so that the difference between the sensing data Sdata detected during the product manufacturing process and the additionally detected sensing data Sdata' can be minimized. In this regard, the compensation parameters can be corrected so that the additionally detected sensing data Sdata' is more similar to the sensing data Sdata detected during the product manufacturing process.

[0117] In addition, the organic light-emitting display device can compensate for the difference between the mobility and the difference between the threshold voltage of the driving TFT of the sub-pixel based on the temperature and degradation characteristics under the commercial and actual use state, and can perform external compensation so that the mobility and threshold voltage characteristics of each driving TFT after compensation are similar to the mobility and threshold voltage characteristics measured during panel manufacturing to the greatest extent. Therefore, the operating characteristics of the organic light-emitting element can be further improved. Further, specifically, for external compensation under the commercial state, the calculated compensation parameters are as similar as possible to the reference parameters set for external compensation during panel manufacturing, and then external compensation can be performed based on the compensation parameters. Therefore, the efficiency of external compensation can be further improved.

[0118] Although the embodiments of the present disclosure have been described in more detail with reference to the accompanying drawings, the present disclosure is not necessarily limited to these embodiments. The present disclosure can be implemented in various modified ways without departing from the technical ideas of the present disclosure. Therefore, the embodiments disclosed in the present disclosure are not intended to limit the technical ideas of the present disclosure, but are used to describe the present disclosure. The scope of the technical ideas of the present disclosure is not limited by the embodiments. Therefore, it should be understood that the above-mentioned embodiments are illustrative and non-restrictive in all aspects. The scope of the present disclosure should be interpreted by the claims, and all technical ideas within the scope of the present disclosure should be understood to be included in the scope of the present disclosure.

Claims

1. An organic light emitting display device, comprising: A display panel including a plurality of sub-pixels respectively arranged at intersections between a plurality of gate lines and a plurality of data lines; a gate driver configured to supply a scan signal to each of the plurality of gate lines; a data driver configured to supply a data voltage to each of the plurality of data lines, wherein the data driver is configured to: detect a driving voltage of each sub-pixel through each of a plurality of sensing lines connected to the sub-pixel, and generate sensing data based on the detected driving voltage of each sub-pixel; and a controller configured to generate reference parameters for compensating for differences between operating characteristics of sub-pixels based on the sensing data, compensate image data using the reference parameters, and output the compensated image data, Wherein, the controller is further configured as: controlling the gate driver and the data driver so that additional sensing data is generated; calculating compensation parameters based on the additional sensed data; compensating the image data using the calculated compensation parameters and outputting the compensated image data; and The compensation parameter is corrected so that a difference between the sensed data detected for generating the reference parameter and the additional sensed data is minimized.

2. The organic light emitting display device according to claim 1, wherein: The controller is also configured to: generating a gate control signal and a data control signal to allow the data driver to sense a driving voltage of a driving transistor of each sub-pixel, and transmitting the gate control signal and the data control signal to the gate driver and the data driver, respectively, during an image non-display period; and The additional sensing data of each sub-pixel generated using the data driver is compared and analyzed, and the compensation parameter is generated based on the comparison and analysis results so that each of the difference between the mobility of the driving transistors of the sub-pixels and the difference between the threshold voltages of the driving transistors is minimized.

3. The organic light emitting display device according to claim 2, wherein: The controller is further configured to gradually update the compensation parameter so that the additional sensing data gradually approaches the sensing data detected for generating the reference parameter.

4. The organic light emitting display device according to claim 2, wherein: The controller comprises: External compensator, configured as: comparing and analyzing the sensing data detected for generating the reference parameter, and generating the reference parameter based on the comparison and analysis result to compensate for each of a difference between mobilities of the driving transistors of the sub-pixels and a difference between threshold voltages of the driving transistors; and comparing and analyzing the additional sensing data, generating the compensation parameter based on the comparison and analysis results, and compensating the image data using the reference parameter or the compensation parameter; and The control signal generator is configured as: generating a gate control signal and a data control signal for image display, and transmitting the gate control signal and the data control signal to the gate driver and the data driver respectively during an image display period; and A gate control signal and a data control signal for sensing the mobility and the threshold voltage of each driving transistor of each sub-pixel are generated, and the gate control signal and the data control signal are transmitted to the gate driver and the data driver respectively during an image non-display period.

5. The organic light emitting display device according to claim 1, wherein: Each sub-pixel consists of: a switching transistor configured to supply a data voltage from each data line to a first node in response to the scan signal from each of the gate lines; a storage capacitor configured to charge and discharge the data voltage for detection supplied to the first node into and from the storage capacitor; a driving transistor configured to supply a high potential voltage to an organic light emitting element connected to a second node based on a magnitude of the data voltage for detection supplied to the first node; and The sensing transistor is configured to transmit the driving voltage outputted to the second node by the driving transistor to the sensing line in response to a sensing control signal from the gate driver.

6. The organic light emitting display device according to claim 5, wherein: The controller is further configured to generate a gate control signal and a data control signal so that a period for sensing the mobility and the threshold voltage of each driving transistor of each sub-pixel is divided into: an initialization period, wherein a sensing initialization voltage is applied to the sensing transistor and the sensing line; a programming period, wherein the data voltage is transmitted to the data line during a turn-on period of the switch transistor; a driving voltage maintaining period, wherein the sensing transistor is turned on so that the driving voltage of the driving transistor is transmitted to the sensing line; as well as a reset period in which the driving voltage of the driving transistor is transmitted to the data driver through the sensing transistor and the sensing line.

7. The organic light emitting display device according to claim 5, wherein: The controller is further configured to generate a gate control signal and a data control signal so that a period for sensing the mobility and the threshold voltage of each driving transistor of each sub-pixel is divided into: an enabling period, wherein the switch transistor and the sensing transistor are turned on, and a sensing initialization voltage is applied to the sensing transistor and the sensing line so that the storage capacitor is charged with the data voltage; a degradation maintenance period, in which the switch transistor is maintained in an on state and the sensing transistor is turned off so that the drive transistor is activated; a driving voltage variation period, wherein the sensing transistor is turned on and the magnitude of the driving voltage of the driving transistor is maintained at a constant level; a driving voltage output control period in which the driving voltage of the driving transistor is supplied to the sensing line while the gate-source voltage of the driving transistor is higher than the threshold voltage of the driving transistor; as well as a driving voltage sensing period, wherein the driving voltage of the driving transistor is transmitted to the data driver through each sensing line.

8. An organic light emitting display device, comprising: The display panel includes a plurality of sub-pixels respectively arranged at intersections between a plurality of gate lines and a plurality of data lines, a gate driver and a data driver configured to drive the plurality of sub-pixels; as well as a controller configured to control the gate driver and the data driver, Wherein, each sub-pixel of the plurality of sub-pixels comprises: a switching transistor configured to supply a data voltage for detection from each data line to the first node in response to a scan signal of each gate line; a storage capacitor configured to charge and discharge the storage capacitor using the data voltage supplied to the first node; a driving transistor configured to supply a high potential voltage to an organic light emitting element connected to a second node based on a magnitude of the data voltage supplied to the first node; and a sensing transistor configured to transmit the driving voltage outputted to the second node by the driving transistor to each of the sensing lines in response to a sensing control signal, wherein the controller is configured to: generate reference parameters for compensating for differences between operating characteristics of sub-pixels based on the sensing data, compensate image data using the reference parameters, and output the compensated image data, Wherein, the controller is further configured as: controlling the gate driver and the data driver so that additional sensing data is generated; calculating compensation parameters based on the additional sensed data; compensating the image data using the calculated compensation parameters and outputting the compensated image data; and The compensation parameter is corrected so that a difference between the sensed data detected for generating the reference parameter and the additional sensed data is minimized.

9. The organic light emitting display device according to claim 8, wherein: Each sub-pixel also includes: an initialization switching element configured to apply a sensing initialization voltage to the sensing line and the sensing transistor in response to an initialization control signal from the gate driver; an enable switch element configured to apply a display enable voltage to the sense line and the sense transistor in response to an enable control signal from the gate driver; and A line switching element is configured to connect each sensing line to the data driver or disconnect each sensing line from the data driver in response to a sampling signal from the gate driver.

10. The organic light emitting display device according to claim 9, wherein: The controller is further configured to generate a gate control signal and a data control signal so that a period for sensing the mobility and the threshold voltage of each driving transistor of each sub-pixel is divided into: an enabling period, wherein the switch transistor and the sensing transistor are turned on, and a sensing initialization voltage is applied to the sensing transistor and the sensing line so that the storage capacitor is charged with the data voltage; a degradation maintenance period, in which the switch transistor is maintained in an on state and the sensing transistor is turned off so that the drive transistor is activated; a driving voltage variation period, wherein the sensing transistor is turned on and the magnitude of the driving voltage of the driving transistor is maintained at a constant level; a driving voltage output control period in which the driving voltage of the driving transistor is supplied to the sensing line while the gate-source voltage of the driving transistor is higher than the threshold voltage of the driving transistor; as well as a driving voltage sensing period, wherein the sampling signal is supplied to the line switching element so that the driving voltage of the driving transistor is transmitted to the data driver through each sensing line.

11. The organic light emitting display device according to claim 10, wherein: The data driver is configured to sense a driving voltage of each sub-pixel through each of the sensing lines to generate sensing data based on the driving voltage of each sub-pixel, and The controller is configured to generate reference parameters for compensating for differences between operating characteristics of sub-pixels based on the sensing data, compensate image data using the reference parameters, and output the compensated image data.

12. The organic light emitting display device according to claim 8, wherein: The controller is further configured to gradually update the compensation parameter so that the additional sensing data gradually approaches the sensing data detected for generating the reference parameter.

Images