KR20170118467A - Organic light emitting display device - Google Patents

Abstract

An object of the present invention is to provide a method and apparatus for performing external compensation using a sensing value received from a randomly selected horizontal line, starting a blanking time immediately before addressing for sensing, And converting the input image data into sensing region compensation image data using sensing region compensation values corresponding to the sensing region compensation values. To this end, the OLED display according to the present invention includes a panel, a sensing unit, a control unit, a data driver, and a gate driver. The sensing unit performs sensing for external compensation on a randomly selected horizontal line among the horizontal lines to collect sensing data. The controller calculates the external compensation value by using the sensing data to determine a change in the characteristic of each subpixel, and calculates an external compensation value using the sensing region compensation values corresponding to the regions set according to the horizontal line on which the sensing is performed. And converts the image data into sensing area compensation image data. The data driver outputs a sensing region compensated data voltage corresponding to the sensed region compensated image data to a data line formed on the panel. The gate driver sequentially outputs gate pulses to the gate lines provided in the panel. The sensing region compensation value is different for each of the regions.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light-

The present invention relates to an organic light emitting display, and more particularly, to an organic light emitting display capable of performing external compensation through a sensing line.

Flat panel display devices (FPDs) are used in various types of electronic products including mobile phones, tablet PCs, and notebook computers. The flat panel display device includes a liquid crystal display device (LCD), a plasma display panel device (PDP), and an organic light-emitting diode display device (OLED) Electrophoretic display devices (EPDs) are also widely used.

In particular, the organic light emitting diode (OLED) uses a self-luminous element that emits light by itself, and thus has advantages such as a fast response speed, a high luminous efficiency, a high luminance, and a large viewing angle.

The organic light emitting display device is a self light emitting device that displays an image by emitting an organic light emitting diode by using recombination of electrons and holes, has a high response speed and low power consumption, and uses a self light emitting device. It has a viewing angle. Therefore, the organic light emitting display device is attracting attention as a next generation flat panel display.

However, in the conventional organic light emitting display device, a characteristic deviation such as a threshold voltage (Vth) and mobility of the driving transistor occurs for each pixel for reasons of process variation, deterioration and the like. Therefore, the amount of current for driving each of the organic light emitting diodes is different, thereby causing a luminance deviation between the pixels.

In order to solve the above problem, Korean Patent Laid-Open Publication No. 10-2013-0066449 (hereinafter referred to as "Prior Art Document") discloses a technique for compensating for a change in characteristics of driving transistors included in each pixel through correction of input image data An external compensation method is disclosed.

FIG. 1 is a diagram illustrating a driving method of an organic light emitting display panel proposed in the development stage of the present invention. 1, the vertical axis represents the top and bottom of the organic light emitting display panel. Accordingly, Figure 1 shows an organic light emitting display panel having 2160 horizontal lines. In Fig. 1, the horizontal axis represents time. When one frame period is 8.3 ms, FIG. 1 shows three frame periods.

Conventionally, an external compensation value is generated by sensing a mobility or a threshold voltage of each pixel provided in one horizontal line at a blanking time between a frame and a frame during driving of the organic light emitting display device. This method is called a high-speed sensing method during driving.

However, when the high-speed sensing method is used during the driving as described above, the brightness difference may occur between the lines because the points of light emission after the blanking time are different depending on the horizontal line. In order to solve this problem, a method of changing the blanking time to the point immediately before the addressing for sensing has been proposed. This method is called a progressive sensing method.

However, when the progressive sensing method is used, since the horizontal lines are sequentially changed, a phenomenon that the horizontal lines are seen in the user's eyes may occur. To solve this problem, a random progressive sensing method as shown in FIG. 1 has been proposed.

In the organic light emitting display in which the random progressive sensing method is used, as shown in Fig. 1, the blanking time starts at a point immediately before the addressing for sensing, and the horizontal line can be changed at random.

In the organic light emitting display device using the random progressive sensing method, as shown in FIG. 1, three regions can be generated.

The first area (a) indicates an area disposed at the upper end of the horizontal line where sensing is performed in the current frame period and disposed at the upper end of the horizontal line where the sensing is performed in the next frame period.

The second region (b) indicates a region disposed at the lower end of the horizontal line where the sensing is performed in the current frame period and disposed at the upper end of the horizontal line where the sensing is performed in the next frame period.

The third region (c) indicates an area disposed at the upper end of the horizontal line where the sensing is performed in the current frame period and disposed at the lower end of the horizontal line where the sensing is performed in the next frame period.

In addition, there may be a region disposed at the lower end of the horizontal line where the sensing is performed in the current frame period and disposed at the lower end of the horizontal line where the sensing is performed in the next frame period. The characteristic of the region is the same as the characteristic of the first region (a).

In the three regions (a, b, c) as described above, the emission sustaining periods are different. For example, in FIG. 1, the emission sustain period of the pixels included in the third region (c) is the longest, the emission sustain period of the pixels included in the first region (a) ) Has the shortest emission sustain period of the pixels included in the pixel.

Due to the difference in the light emission sustain period as described above, a luminance difference may occur between the regions.

In order to solve the above problems, an object of the present invention is to perform external compensation using a sensing value received from a randomly selected horizontal line, to start a blanking time immediately before addressing for sensing, And converting the input image data into sensing region compensation image data using sensing region compensation values corresponding to the three regions set in accordance with the horizontal line in which the sensing region compensation values are set.

According to an aspect of the present invention, there is provided an organic light emitting display including a panel, a sensing unit, a controller, a data driver, and a gate driver. The panel is provided with subpixels along imaginary horizontal lines corresponding to gate lines. The sensing unit performs sensing for external compensation on a randomly selected horizontal line among the horizontal lines to collect sensing data. The controller calculates the external compensation value by using the sensing data to determine a change in the characteristic of each subpixel, and calculates an external compensation value using the sensing region compensation values corresponding to the regions set according to the horizontal line on which the sensing is performed. And converts the image data into sensing area compensation image data. The data driver outputs a sensing region compensated data voltage corresponding to the sensed region compensated image data to a data line formed on the panel. The gate driver sequentially outputs gate pulses to the gate lines provided in the panel. The sensing region compensation value is different for each of the regions.

According to the present invention, in the case where external compensation is performed in real time, the occurrence of a luminance difference in each region of the panel can be reduced according to the position of a horizontal line where sensing is performed.

According to the present invention, since the block dim or the flicker is reduced, the image quality can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a driving method of an organic light emitting display panel proposed in the development stage of the present invention; FIG.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light emitting diode (OLED) display.
4 is a view illustrating a configuration of a data driver applied to an OLED display according to an embodiment of the present invention.
5 is a view illustrating a structure of pixels formed on a panel applied to an OLED display according to an exemplary embodiment of the present invention.
6 is a view illustrating a structure of a pixel formed on a panel applied to an OLED display according to an embodiment of the present invention.
FIG. 7 is a view illustrating a configuration of a gate driver applied to an organic light emitting display according to an embodiment of the present invention; FIG.
8 is a flow chart of an embodiment of a method of driving an organic light emitting display according to the present invention.
9 is a diagram illustrating an exemplary driving method of an OLED display according to an exemplary embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. To fully disclose the scope of the invention to a person skilled in the art, and the invention is only defined by the scope of the claims.

It should be noted that, in the specification of the present invention, the same reference numerals as in the drawings denote the same elements, but they are numbered as much as possible even if they are shown in different drawings.

The shapes, sizes, ratios, angles, numbers, and the like disclosed in the drawings for describing the embodiments of the present invention are illustrative, and thus the present invention is not limited thereto. Like reference numerals refer to like elements throughout the specification. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. In the case where the word 'includes', 'having', 'done', etc. are used in this specification, other parts can be added unless '~ only' is used. Unless the context clearly dictates otherwise, including the plural unless the context clearly dictates otherwise.

In interpreting the constituent elements, it is construed to include the error range even if there is no separate description.

In the case of a description of the positional relationship, for example, if the positional relationship between two parts is described as 'on', 'on top', 'under', and 'next to' Or " direct " is not used, one or more other portions may be located between the two portions.

In the case of a description of a temporal relationship, for example, if the temporal relationship is described by 'after', 'after', 'after', 'before', etc., May not be continuous unless they are not used.

The term " at least one " should be understood to include all possible combinations from one or more related items. For example, the meaning of 'at least one of the first item, the second item and the third item' means not only the first item, the second item or the third item, but also the second item, the second item and the third item, Means any combination of items that can be presented from more than one.

The first, second, etc. are used to describe various components, but these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical spirit of the present invention.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other, partially or wholly, technically various interlocking and driving, and that the embodiments may be practiced independently of each other, It is possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention can be applied to various kinds of display devices using external compensation. Hereinafter, for convenience of explanation, an organic light emitting display device will be described as an example of the present invention.

FIG. 2 is a schematic view illustrating the structure of an organic light emitting display according to the present invention, FIG. 3 is a view illustrating a structure of a control unit applied to the organic light emitting display according to the present invention, and FIG. FIG. 5 is a view illustrating the structure of pixels formed on a panel applied to the organic light emitting diode display according to the present invention, and FIG. 6 is a cross- FIG. 7 is a view illustrating a structure of a gate driver applied to an OLED display according to an exemplary embodiment of the present invention. Referring to FIG.

The present invention is intended to reduce a phenomenon in which a luminance difference is generated in each region of a panel according to the position of a horizontal line where sensing is performed when external compensation is performed in real time.

In particular, the present invention relates to an organic light emitting display using a random progressive sensing method. In an organic light emitting display using a random progressive sensing method, a threshold voltage or mobility of subpixels included in a predetermined horizontal line is randomly selected in a predetermined order among virtual horizontal lines corresponding to gate lines . The horizontal line means an imaginary line parallel to at least one gate line.

In the organic light emitting display device using the random progressive sensing method, gate pulses output to any one of the gate lines are delayed during one frame period in which gate pulses are output to all of the gate lines provided in the panel, At the output blanking time, the threshold voltage or mobility is sensed.

Therefore, the blanking time at which no image is output is included in one frame period. During the blanking time, the OLED display is driven in a sensing mode.

In the organic light emitting display device using the random progressive sensing method, three regions can be generated. The first area indicates the area disposed at the upper end of the horizontal line where the sensing is performed in the current frame period and the upper area of the horizontal line where the sensing is performed in the next frame period. The second region is disposed at the lower end of the horizontal line where the sensing is performed in the current frame period and is located at the upper end of the horizontal line where the sensing is performed in the next frame period. The third area indicates an area disposed at the upper end of the horizontal line where the sensing is performed in the current frame period and disposed at the lower end of the horizontal line in which the sensing is performed in the next frame period. In addition, there may be a fourth region disposed at the lower end of the horizontal line where the sensing is performed in the current frame period and disposed at the lower end of the horizontal line where the sensing is performed in the next frame period. However, the characteristic of the fourth region is the same as that of the first region (a). Accordingly, the present invention will be described below with reference to the three regions.

In the above-described three regions, the light emission sustain periods are different from each other, so that a luminance difference may occur between the regions.

The present invention relates to an organic light emitting display in which a random progressive sensing method is used to prevent a phenomenon in which luminance is varied depending on positions of three regions set in accordance with a horizontal line on which sensing is performed, .

To this end, the present invention performs external compensation using a sensing value received from a randomly selected horizontal line, and starts a blanking time immediately before addressing for sensing. The present invention converts input image data into sensing area compensation image data using sensing area compensation values corresponding to three areas set according to the horizontal line on which the sensing is performed. According to the present invention, a luminance difference between regions is not generated.

2 to 7, the organic light emitting diode display according to the present invention includes subpixels 110 formed of organic light emitting diodes along virtual horizontal lines corresponding to the gate lines GL1 to GLg, A sensing unit 320 for performing sensing for external compensation on a randomly selected horizontal line among the horizontal lines and collecting sensing data, and a sensing unit 320 for sensing, using the sensing data, And a control unit for converting the input image data into sensing area compensation image data using sensing area compensation values corresponding to the areas set according to the horizontal line on which the sensing is performed, And a sensing area compensated data voltage corresponding to the sensed area compensated image data is output to a data line DL formed on the panel 100. [ Driver 300 and a gate driver 200 for sequentially outputting a gate pulse to the gate lines (GL1 to GLg) provided in the panel 100. In this case, the sensing region compensation value differs from region to region. Here, the sensing unit 320 may be included in the data driver 300 or independently of the data driver 300. Hereinafter, an OLED display device in which the sensing unit 320 is provided in the data driver 300 will be described as an example of the present invention. The sensing unit 320, the controller 400, the data driver 300, and the gate driver 200 are collectively referred to as a panel driver.

6, the panel 100 defines a pixel region in which the subpixels 110 and the subpixels 110 are formed and supplies a driving signal to the pixel driving circuit PDC Signal lines DL, PLA, PLB, SL and SCL are formed. Each of the subpixels 110 includes an organic light emitting diode (OLED) and the pixel driving circuit (PDC). The pixel driving circuit PDC includes a driving transistor Tdr for controlling a current flowing in the organic light emitting diode OLED.

First, the signal lines include a scan control line (SCL), a data line (DL), a sensing line (SL), a first driving power supply line (PLA), and a second driving power supply line (PLB).

Next, the scan control lines SCL are formed so as to be spaced apart from each other along the second direction of the panel 100, that is, the horizontal direction. 6 shows a case where the gate electrode of the first switching transistor Tsw1 for controlling the light emission of the organic light emitting diode OLED and the gate electrode of the second switching transistor Tsw2 for sensing the characteristic change of the driving transistor Tdr are one The scan electrode of the first switching transistor Tsw1 and the gate electrode of the second switching transistor Tsw2 are different from each other in the subpixel 110 connected to the scan control line SCL of FIG. And may be connected to a scan control line.

For example, the gate electrode of the first switching transistor Tsw1 may be connected to the first scan control line, and the gate electrode of the second switching transistor Tsw2 may be connected to the second scan control line. In this case, when the first switching transistor Tsw1 is turned on, the second switching transistor Tsw2 may be turned off, and when the first switching transistor Tswl is turned off, (Tsw2) can be turned on.

The data lines DL may be arranged to be spaced apart from each other at regular intervals along the first direction, that is, the longitudinal direction, of the panel 100 so as to cross the scan control lines SCL.

Next, the sensing lines SL may be formed at regular intervals to be parallel to the data lines DL.

At least three of the sub-pixels 110 form one unit pixel 120. In the following description, four subpixels 110 (red subpixel R, white subpixel W, green subpixel G and blue subpixel B), as shown in FIG. 5, The present invention will be described by way of an example in which one unit pixel 120 is formed. In this case, one sensing line (SL) may be commonly connected to the unit pixel (120). Therefore, when d data lines DL1 to DLd are formed on the horizontal line of the panel 100, the number k of the sensing lines SL is d / 4.

In detail, the data lines DL1 to DLd are formed in the first direction (longitudinal direction) of the panel 100, and the sensing lines SL are formed in parallel with the data lines As shown in FIG. 5, each of the sensing lines SL is connected to at least three sub-pixels 110 constituting each of the unit pixels 120 formed in one horizontal line have. However, the sensing line may be provided for each sub-pixel.

Next, the first driving power supply line PLA may be formed at regular intervals to be parallel to the data lines DL. Here, the first driving power line PLA may be spaced apart from the sensing line SL at regular intervals. The first driving power supply line (PLA) is connected to a driving power supply unit and supplies a first driving power supply (EVDD) supplied from a driving power supply unit to each subpixel 110.

The second driving power line PLB is formed on the entire surface of the panel 100 or aligned with the data lines DL1 to DLd or the scan control lines SCL, Or may be formed at regular intervals. The second driving power supply line (PLB) supplies a second driving power source (EVSS) supplied from the driving power supply unit to each subpixel 110. Alternatively, the second driving power supply line may be electrically grounded to a case (or cover) of a metal material constituting the organic light emitting display. In this case, the second driving power supply line may be grounded to each subpixel 110, Provide power (ground).

Finally, each of the plurality of subpixels 110 is formed for each pixel region defined by each of the scan control lines SCL and the data lines DL1 to DLd, which intersect with each other. Here, each of the plurality of subpixels 110 may be any one of a red subpixel, a green subpixel, a blue subpixel, and a white subpixel.

One unit pixel 120 includes adjacent red subpixels, white subpixels, green subpixels, and blue subpixels, or may include red subpixels, green subpixels, and blue subpixels, as shown in FIG. 5 . 5, two unit pixels 120 each composed of a red subpixel R, a white subpixel W, a green subpixel G and a blue subpixel B are shown.

Each of the plurality of subpixels 110 may include a pixel driving circuit PDC and an organic light emitting diode OLED, as shown in FIG.

The pixel driving circuit PDC includes a first switching transistor Tsw1, a second switching transistor Tsw2, a driving transistor Tdr, and a capacitor Cst. Here, the transistors Tsw1, Tsw2, and Tdr are thin film transistors (TFTs), and may be a-Si TFTs, poly-Si TFTs, oxide TFTs, organic TFTs, or the like.

The first switching transistor Tsw1 is switched by the gate pulse SP and outputs a data voltage Vdata supplied to the data line DL. The first switching transistor Tsw1 includes a gate electrode connected to an adjacent scan control line SCL, a first electrode connected to an adjacent data line DL and a first electrode connected to a gate electrode of the driving transistor Tdr lt; RTI ID = 0.0 > n1. < / RTI >

The second switching transistor Tsw2 is switched by the gate pulse to supply the reference voltage Vref supplied to the sensing line SL to the second node n2 which is the source electrode of the driving transistor Tdr. To this end, the second switching transistor Tsw2 includes a gate electrode connected to the scan control line SCL, a first electrode connected to the adjacent sensing line SL, and a second electrode connected to the second node n2.

The capacitor Cst includes electrodes connected between the gate electrode of the driving transistor Tdr and the first electrode, that is, the first and second nodes n1 and n2. For example, a first electrode of the capacitor Cst is connected to the first node n1, and a second electrode of the capacitor Cst is connected to the second node n2. The capacitor Cst charges the difference voltage of the voltage supplied to the first and second nodes n1 and n2 according to the switching of the first and second switching transistors Tsw1 and Tsw2, And switches the driving transistor Tdr according to the voltage.

The driving transistor Tdr controls the amount of current flowing from the first driving power supply line PLA to the organic light emitting diode OLED by being turned on by the voltage of the capacitor Cst. The driving transistor Tdr includes a gate electrode coupled to the first node n1, a first electrode coupled to the second node n2, and a second electrode coupled to the first driving power line PLA. do.

The organic light emitting diode OLED emits light having a luminance corresponding to the data current Ioled by the data current Ioled supplied from the driving transistor Tdr. For this, the organic light emitting diode OLED includes a first electrode (for example, an anode electrode) connected to the second node n2, that is, a first electrode of the driving transistor Tdr, An organic layer and a second electrode (e.g., a cathode electrode) connected to the organic layer. The second electrode of the organic light emitting diode may be the second driving power supply line PLB formed on the organic layer or may be additionally formed on the organic layer to be connected to the second driving power supply line PLB.

In the above description, the structure of the subpixel 110 for performing external compensation is described with reference to FIG. 6, but the subpixel 110 may be formed in various structures in addition to the structure shown in FIG. 6 .

For example, the external compensation is a method of calculating the amount of change in threshold voltage or mobility of the driving transistor Tdr formed in the subpixel 110, and calculating the amount of change of the data voltage supplied to the unit pixel It means to vary the size. Therefore, the structure of the sub-pixel 110 can be changed into various forms so that the threshold voltage or the variation amount of the mobility of the driving transistor Tdr can be calculated.

The method of calculating the amount of change in threshold voltage or mobility of the driving transistor Tdr using the subpixel 110 for external compensation is also variously changed according to the structure of the subpixel 110 .

In other words, the present invention is intended to prevent a luminance difference from occurring between regions set according to the position of a horizontal line where sensing for external compensation is performed in an organic light emitting display device performing external compensation . Thus, the structure of the subpixel for external compensation and the method of performing external compensation can be selected from the various subpixel structures and various external compensation methods currently proposed for external compensation. For example, the structure of the subpixel for external compensation and the method of performing external compensation can be applied to structures and methods disclosed in a number of patents, including Japanese Laid-Open Patent Application No. 10-2013-0066449 And the invention disclosed in Application No. 10-2013-0150057 and Application No. 10-2013-0149213 filed by the present applicant may also be applied.

That is, the specific structure of the subpixel for performing external compensation and the specific method of external compensation are outside the scope of the present invention. Thus, an example of a subpixel for external compensation has been briefly described with reference to FIG. 6, and an external compensation method is also briefly described below.

Second, the panel driving unit operates the panel 100 in a sensing mode or in a display mode.

The sensing mode refers to a blanking time driving mode in which no image is displayed. That is, the sensing mode means a driving mode during a sensing period. In each of the frame periods, the starting point of the blanking time is randomly changed every frame period. In the sensing mode, an external compensation value for correcting the characteristic change of the driving transistor Tdr is calculated.

The display mode means a driving mode during a period in which the sensing is not performed. In the display mode, an image is output to the panel 100. In the display mode, the input image data is converted into external compensation image data using the external compensation value, and the external compensation data voltage corresponding to the external compensation image data is supplied to the panel through the data line.

The panel driver may control a characteristic change of the driving transistors Tdr included in each subpixel 110 (for example, threshold voltage or mobility) through each of the first through k-th sensing lines in the sensing mode, ) To generate sensing data (Sdata).

The panel driver calculates the external compensation value based on the sensing data (Sdata), corrects the input image data (ID) input from the external system using the external compensation value, and outputs the external compensation video data . The panel driver converts the external compensation video data into an external compensation data voltage and supplies the data to the corresponding subpixel 110.

For example, the panel driver senses a characteristic change of each of the driving transistors Tdr through each of the sensing lines to separately compensate for a characteristic change of the driving transistors Tdr included in each subpixel 110 Compensates the input image data ID by using the characteristic variation amount of each of the sensed driving transistors Tdr and converts the compensated external compensation image data into external compensation data voltages, .

As shown in FIGS. 2 to 4, the panel driving unit includes a sensing unit 320 that performs sensing for external compensation for each horizontal line of the panel 100 to collect sensing data Sdata, (Sdata) to calculate an external compensation value by judging a characteristic change of each subpixel, a sensing region compensation value corresponding to three regions set according to a horizontal line on which the sensing is performed A data alignment unit 430 for converting the input image data ID into sensing area compensation image data, and a sensing area compensation data voltage corresponding to the sensing area compensation image data, A data driver 300 for outputting a sensing data voltage to the data line when the sensing is performed, And a gate driver 200 for supplying the (GS).

The data arrangement unit 430 may be formed in the control unit 400 that controls the data driver 300 and the gate driver 200. The calculating unit 410 may be included in the control unit 400 or may be formed independently of the control unit 400. The control unit 400 includes a control signal generation unit 420 for generating various control signals DCS and GCS and control signals generated from the control signal generation unit 420 to the gate driver 200, And an output unit 440 for transmitting the sensing area compensated image data to the data driver 300 or the sensing area compensated image data generated from the data aligner 430 to the data driver 300.

The sensing unit 320 may be formed in the data driver 300 or independently of the data driver 300. The sensing unit 320 is included in the data driver 300 as shown in FIG. 4 and the calculating unit 410 may include the controller 400 An organic light emitting display according to the present invention will be described as an example.

In this case, the data driver 300 may include a data voltage output unit 310 for supplying various data voltages (Vdata) to the panel and the sensing unit 320 as shown in FIG. 4 . However, the panel driving unit, which is applied to the organic light emitting display according to the present invention, may have various structures other than the structures described below.

The control unit 400 controls the gate driver 200 and the data driver 300 based on a timing synchronization signal TSS input from an external system and a gate control signal GCS for controlling driving of the gate driver 200, And a data control signal DCS for controlling the data control signal DCS.

Also, the controller 400 transmits the sensing image data to be supplied to the pixels formed on the horizontal line where the external compensation is performed, to the data driver 300.

The sensing for the external compensation is performed at the blanking time. The start time of the blanking time differs every frame period. The start time of the blanking time is randomly set in advance and stored in the storage unit 450.

The controller 400 calculates the external compensation value based on the sensing data Sdata provided from the data driver 300 in the sensing mode and outputs the external compensation value to the storage unit 450. [ . The storage unit 450 may be included in the control unit 400 or may be independently formed outside the control unit 400.

The controller 400 converts the input image data into sensing area compensated image data (Data) using sensing area compensation values corresponding to three areas set according to an external compensation value and a horizontal line on which the sensing is performed .

As described above, the areas are arranged in the upper part of the horizontal line where the sensing is performed in the current frame period, and are arranged in the upper part of the sensing line where the sensing is performed in the next frame period. In the current frame period, A second region disposed at the lower end of the horizontal line where the sensing is performed in the current frame period and a second region disposed at the upper end of the horizontal line in which sensing is performed in the next frame period, And a fourth region disposed at the lower end of the horizontal line and a fourth region disposed at the lower end of the horizontal line for sensing in the current frame period and disposed at the lower end of the horizontal line for sensing in the next frame period. Here, the characteristic of the fourth region is the same as the characteristic of the first region. Therefore, in the following, the present invention will be described by exemplifying the first region, the second region, and the third regions.

When the input image data is received, the controller 400 determines an area corresponding to the input image data among the three areas (first to third areas), and determines a sensing area compensation To the input image data, and converts the sensed region-compensated image data (Data).

When the input image data is received, the controller 400 determines an area corresponding to the input image data among the three areas (first to third areas). The controller 400 applies the sensing area compensation value corresponding to the area and the external compensation value corresponding to the subpixel to which the input image data is to be output to the input image data, Conversion. The control unit outputs the sensing area compensated image data Data to the data driver 300 (or the data voltage output unit 310).

The data driver 300 (or the data voltage output unit 310) outputs a data voltage corresponding to the sensing area compensated image data to a data line formed in the panel in each horizontal period.

Therefore, when there is no external compensation value corresponding to the subpixel to which the input image data ID is to be output, the sensing region compensation image data Data is obtained by using the input image data ID and the sensing region compensation value .

When the external compensation value corresponding to the subpixel to which the input image data ID is to be output is calculated, the sensing region compensation image data Data is input to the input image data ID, the external compensation value, Value.

3, the controller 400 uses the timing synchronization signal TSS transmitted from the external system to input the input video data (video data) transmitted from the external system A data alignment unit 430 for rearranging the sensing area compensated image data by using at least one of an external compensation value and a sensing area compensation value and supplying the rearranged sensing area compensated image data Data to the data driver 300, A control signal generator 420 for generating the gate control signal GCS, the data control signal DCS and the power control signal PCS using a synchronization signal, For calculating an external compensation value for compensating for a characteristic change of the driving transistor formed in each of the pixels using the sensing data (Sdata) A storage unit 450 for storing the external compensation value and the sensing region compensation value generated for the present invention, and various sensing region compensated image data Data generated by the data aligning unit 430 And an output unit 440 for outputting various control signals DCS and GCS to the data driver 300 or the gate driver 200.

The calculating unit 410 determines the characteristic change of each subpixel using the sensing data, and calculates the external compensation value. For example, the calculating unit 410 senses a change in the characteristics of the organic light emitting diodes (OLEDs) using the sensing data (Sdata) in the sensing mode performed at the blanking time. The calculating unit 410 may calculate the external compensation value according to the characteristic change and store the external compensation value in the storage unit 450.

The data sorting unit 430 may sort the input image data IDs transmitted from the external system by at least one of an external compensation value and a sensing area compensation value using a timing synchronization signal TSS transmitted from an external system And supplies the re-arranged sensing area compensated image data (Data) to the data driver 300.

The control signal generator 420 generates various control signals required in the present invention.

As described above, the storage unit 450 stores the sensing region compensation value and the external compensation value transmitted from the calculation unit 410, and transmits the sensing compensation value to the data alignment unit 430 do. In addition, the storage unit 450 stores the order of the horizontal lines to be sensed. The above sequence can be randomly preset. For example, when the number of gate lines is 2160, sensing is performed for the subpixels connected to the tenth gate line in the first frame period and for the subpixels connected to the 25th gate line in the second frame period The sensing for subpixels connected to the 1000th gate line may be performed in the third frame period. That is, the randomness in the present invention means that the order of the horizontal lines through which the sensing is performed is not made sequentially from the upper end (or the lower end) to the lower end of the panel, but in an irregular order. However, the random order is set in advance and stored in the storage unit 450. Accordingly, the controller 400 can recognize the horizontal line where the sensing is performed.

As described above, the controller 400 selects a horizontal line to perform sensing for external compensation in each frame period in a randomly preset sequence.

The sensing region compensation values applied to the subpixels included in any one of the three regions may be the same.

However, the sensing region compensation values applied to the subpixels included in any one of the three regions may be different. For example, the sensing region compensation values applied to the subpixels included in one of the subpixels may differ depending on at least one of colors and gray of the input image data corresponding to the subpixels . In this case, the sensing region compensation values applied to the subpixels included in any one of the regions may include a reference sensing region compensation that is commonly applied to all subpixels provided in any one of the regions, And an auxiliary sensing area compensation value that is changed according to at least one of a color and a gray of input image data corresponding to the subpixel included in any one of the areas.

The gate driver 200 sequentially generates gate pulses in response to a gate control signal GCS supplied from the controller 400 and sequentially supplies gate pulses to the scan control lines SCL.

Here, the gate control signal GCS may include a start signal, a plurality of clock signals, and the like.

While the gate pulse is not output to the gate line, a turn-off signal that turns off the first switching transistor Tsw1 connected to the gate line is output to the gate line. The gate pulse and the turn-off signal are generically referred to as a gate signal GS.

The gate driver 200 may be formed directly on the panel 100 together with the thin film transistor forming process of each sub pixel 110 or may be formed in the form of an integrated circuit have.

The type in which the gate driver 200 is directly formed on the panel 100 is called a gate in panel (GIP) type. The gate driver 200 of the GIP type may be composed of a plurality of stages (Satage 1 to Stage g) as shown in FIG. In the stages, the gate pulses GP1 to GPg are sequentially output.

The gate pulse outputted from the stage of the previous stage can perform the function of driving the stage of the succeeding stage. In this case, at least one further stage may be provided between the stage of the front stage and the stage of the rear stage.

The gate driver 200 may delay the gate pulse output to the gate line corresponding to the horizontal line to be sensed until the sensing is completed.

To this end, the gate driver 200 may be provided with a delay unit 210 for delaying gate pulses output from the front stage and supplied to the rear stage. The delay unit 210 may be driven according to a gate pulse control signal GPCS transmitted from the controller 400. [

For example, the gate pulse that is output from the front stage and supplied to the rear stage where sensing is performed is not supplied to the rear stage by the delay unit 210. During the sensing period during which the gate pulse is not supplied to the subsequent stage, the controller 400 may calculate the external compensation value by sensing sub-pixels included in the horizontal line corresponding to the gate line connected to the stage at the subsequent stage .

When the sensing period ends, the delay unit 210 supplies the gate pulse to the subsequent stage. Accordingly, gate pulses are supplied to the subpixels included in the horizontal line corresponding to the gate line connected to the subsequent stage, and the subpixels output an image.

The delay unit 210 may be configured in various forms to perform the functions as described above.

The data driver 300 is connected to the data lines DL1 to DLd and the sensing lines and operates in a sensing mode or a display mode according to a control signal transmitted from the controller 400. [ 4, when the data driver 300 includes the data voltage output unit 310 and the sensing unit 320, the data voltage output unit 310 outputs the data voltage DL to the data line DL, And the sensing unit 320 is connected to the sensing lines SL.

The sensing unit 320 supplies a reference voltage to each of the sensing lines in the sensing mode. Then, the sensing unit 320 receives an analog signal corresponding to the reference voltage. The sensing unit 320 converts the analog signal into a digital signal, i.e., the sensing data Sdata. The sensing unit 320 transmits the sensing data to the calculating unit 410. [ Accordingly, a change in the characteristics of the driving transistor Tdr included in the sub-pixels 110 formed on one horizontal line can be sensed.

To this end, the subpixels may be configured as shown in FIG. For example, one sensing line SL is provided for each unit pixel 120 including R, G, B, and W subpixels 110 among the subpixels formed on one horizontal line Respectively. Accordingly, when one sensing data voltage is supplied through each sensing line SL, the sensing data for one subpixel of each unit pixel 120 is transmitted to the sensing unit 320. [ Since one unit pixel 120 is formed of four subpixels, when four sensing data voltages are supplied through the sensing line SL, the number of subpixels Sensing data can be generated. The sensing data for all the subpixels formed on the one horizontal line is transmitted to the calculating unit 410. The calculating unit 410 calculates the external compensation for the subpixels using the sensing data, Value can be calculated.

In the sensing mode, the data voltage output unit 310 converts the output image data transmitted from the controller 400, that is, the sensing image data, into a sensing data voltage and supplies the sensed data voltage to the data line. In the display mode, the data voltage output unit 310 outputs sensing region compensation image data DATA supplied from the controller 400 in units of horizontal lines using a plurality of reference gamma voltages supplied from the reference gamma voltage supply unit, Into a sensing area compensation data voltage and supplies the data to the corresponding data lines DL1 to DLd.

The data voltage output unit 310 samples sensing region compensation image data DATA of each subpixel 110 input in units of one horizontal line according to a data control signal DCS, The gamma voltage corresponding to the gray level value of the sampling data is selected as the sensing area compensation data voltage and supplied to the data line DL of each corresponding sub pixel 110. [

Lastly, the sensing unit 320 senses the voltage of each of the sensing lines in the sensing mode, and generates sensing data (Sdata) corresponding to the sensing voltage and provides the sensed data (Sdata) to the controller 400. For this, the sensing unit 320 may include an analog-to-digital converter for converting the sensing voltage transmitted from the sensing lines to digital to generate the sensing data (Sdata).

The sensing unit 320 performs the sensing at a blanking time at which no data voltage is output to the data lines during one frame period.

In other words, the sensing unit 320 delays a gate pulse output to one of the gate lines during the one frame period in which the gate pulse is output to all of the gate lines, The sensing is performed at the blanking time.

FIG. 8 is a flowchart illustrating a method of driving an organic light emitting display according to an exemplary embodiment of the present invention, and FIG. 9 illustrates an exemplary method of driving an organic light emitting display according to an exemplary embodiment of the present invention. 9, the vertical axis represents the top and bottom of the organic light emitting display panel. Accordingly, FIG. 9 shows an organic light emitting display panel having 2160 horizontal lines. In Fig. 9, the horizontal axis represents time. When one frame period is 8.3 ms, FIG. 1 shows three frame periods. However, since FIG. 9 is for explaining the three areas (x, y, z) described above, the frame periods shown in FIG. 9 do not represent the temporal order. For example, in the case of the first region (x) and the second region (y), the period between 0 and 8.3 ms is the current frame period, and the period between 8.3 and 16.6 ms is the next frame period. Further, in the third region z, the period between 8.3 and 16.6 ms is the current frame period, and the period between 16.6 and 24.9 ms is the next frame period. The same or similar contents as those described above are omitted or briefly described.

First, the sensing area compensation values are stored in the storage unit 450 for each of the three areas (S702).

The three regions described above can be distinguished as shown in FIG.

The first area x indicates an area disposed at the upper end of the horizontal line where sensing is performed in the current frame period and disposed at the upper end of the horizontal line where the sensing is performed in the next frame period.

The second area y indicates an area disposed at the lower end of the horizontal line where the sensing is performed in the current frame period and disposed at the upper end of the horizontal line where the sensing is performed in the next frame period.

The third area z indicates an area disposed at the upper end of the horizontal line where the sensing is performed in the current frame period and disposed at the lower end of the horizontal line where the sensing is performed in the next frame period.

In addition, there may be a fourth region disposed at the lower end of the horizontal line where the sensing is performed in the current frame period and disposed at the lower end of the horizontal line where the sensing is performed in the next frame period. However, the characteristics of the fourth region are the same as those of the first region (x). Therefore, the present invention will be described below by taking the three regions (x, y, z) as an example.

The sensing region compensation value is a value for compensating the luminance deviation of the three regions. The sensing area compensation value is changed according to the input image data and can be used in luminance calculation of the input image data. In other words, the voltage to be added to or subtracted from the input image data may be changed according to the input image data according to the luminance calculation based on the sensing region compensation value.

The sensed area compensation value may be calculated using the calculated various information when the sensing for the external compensation is substantially performed in the manufacturing process of the panel 110 or may be calculated through various simulations, And may be stored in the storage unit 450.

First, the sensing region compensation values are different for each of the three regions. For example, as shown in FIG. 9, the emission period of the second region y is smaller than the emission period of the first region x when the first region x is referred to, The light emitting period of the third region (z) is longer than the light emitting period of the first region (x).

Therefore, when the sensing region compensation value applied to the subpixels provided in the first region (x) has a value that does not change the luminance of the subpixels provided in the first region (y), the second region the sensing region compensation value applied to the subpixels provided in the second region y may have a value that increases the brightness of the subpixels provided in the second region y. In this case, the sensing region compensation value applied to the subpixels provided in the third region z may have a value that reduces the brightness of the subpixels provided in the third region z.

Second, the sensing region compensation values applied to the subpixels included in one of the regions may be the same.

Third, the sensing region compensation values applied to the subpixels included in any one of the regions may include a reference sensing region compensation value, which is commonly applied to all subpixels provided in any one of the regions, And an auxiliary sensing area compensation value that is changed according to at least one of hue and gray of the input image data corresponding to the sub-pixel included in the one area.

For example, even if the sensing region compensation values are applied to the subpixels included in one region, the sensing region compensation values may be different according to the gray of the input image data corresponding to the subpixels, The sensing region compensation values may be different according to the position of the line in the panel, the sensing region compensation values may be different according to the hue corresponding to the input image data corresponding to the sub pixel, The sensing region compensation values may be different depending on at least one of gray, the position of the horizontal line including the subpixel, and the hue corresponding to the subpixel.

In other words, although the sensing area compensation values corresponding to the subpixels included in one area are different, the sensing area compensation values may be different depending on the color of the input image data. For example, the compensation value for the R input image data corresponding to the R subpixel is 0.01 V, the compensation value for the W input image data corresponding to the W subpixel is 0.013 V, the G input image data corresponding to the G subpixel The compensation value for the B input image data corresponding to the B subpixel can be 0.009V.

Also, even though the sensing region compensation values corresponding to the subpixels included in one region, the sensing region compensation values may be different according to the gray of the input image data.

In addition, even if the sensing region compensation values correspond to the subpixels included in one region, the sensing region compensation values may be different according to the position of the horizontal line where the subpixels to which the input image data is to be output.

Also, even though the sensing region compensation values corresponding to the subpixels included in one region, the sensing region compensation values may be different depending on at least two of the gray of the input image data, the position of the horizontal line, and the hue . As described above, since the sensing area compensation value can be variously changed according to the gray of the input image data, the position of the horizontal line, and the hue, the sensing area compensation value is calculated considering all the information .

Next, in the blanking time, that is, in the sensing mode, a data voltage is sequentially supplied to the subpixels forming one unit pixel 120, and a characteristic change of the driving transistors formed in each of the pixels is sensed . That is, the sensing for the external compensation is performed on the randomly selected horizontal line (S704).

In this case, one sensing line may be formed in the unit pixel 120, as shown in FIG. That is, while the reference voltage is applied to one sensing line, a data voltage is supplied only to one of the pixels forming the unit pixel, Can be detected.

The calculation unit 410 may calculate the external compensation value using the sensing data. As described above, the specific method for calculating the external compensation value can be applied to the methods described in the open patent documents and various patent documents filed by the present applicant.

The sensing mode is performed at a blanking time included in one frame period, as shown in FIG. One frame period may be 8.3 ms, for example, as shown in Fig.

In the blanking time, a data voltage is not output to the data lines. However, since the data voltage charged in each subpixel formed in each horizontal line HL is continuously maintained, the image can be output through the panel even at the blanking time.

However, since the sensing data voltage for the sensing is supplied to the blanking time of the subpixels formed on the horizontal line on which the sensing is performed, in the subpixels formed on the horizontal line on which the sensing is performed, No image may be output during blanking time.

Next, the controller 400, in particular, the data aligner 430 rearranges the input image data (IDs) transmitted from the external system using the sensing area compensation values to generate the sensing area compensation image data And transmits the sensing region compensated image data to the data voltage output unit 310.

For example, when the sensing region compensation value applied to the subpixels provided in the first region (x) has a value that does not change the luminance of the subpixels provided in the first region (y) The sensing region compensation value applied to the subpixels included in the second region y may have a value that increases the brightness of the subpixels included in the second region y. In this case, the sensing region compensation value applied to the subpixels provided in the third region z may have a value that reduces the brightness of the subpixels provided in the third region z.

Accordingly, the luminance of the second region (y) having a shorter emission time than the first region (x) can be increased, and the luminance of the third region (z) having a longer emission time than the first region (x) . Thereby, the luminance difference in the three regions (x, y, z) is not generated.

One example of a method for the sensing unit 400 to generate the sensing region compensated image data using the sensing region compensation value is as follows.

First, the light emitting duty of the first region x may be 8.3 ms in total, including an active period and a blanking period (Duty: Active (8 ms) + Blank (0.3 ms) = 8.3 ms). In this case, the relationship between the input luminance data LDATA of the input image data input to the controller 400 and the output luminance data LDATA 'of the sensing region compensated image data output from the controller 400 may be related to the corresponding region Scale_x may be 1 because LDATA '= LDATA x Scale_x multiplied by the weight (Scale_x) and the light emission duty is composed of the active period and the blanking period.

에 의해 생성된 값이다.Here, [1]

Lt; / RTI >

Secondly, the light emitting duty of the second region y corresponds to the active period, and thus can be 8 ms in total. In this case, LDATA '= LDATA x Scale_y and Scale_y can be (8.3 / 8) (Duty: Active = 8ms).

에 의해 생성된 값이다.Here, [8.3 / 8]

Lt; / RTI >

Third, the light emitting duty of the third region z may include an active period and twice a blanking period (Duty: Active + 2 x Blank). In this case, LDATA '= LDATA x Scale_z and Scale_z can be (8.3 / 8.6).

에 의해 생성된 값이다.Here, [8.3 / 8.6]

Lt; / RTI >

Finally, the data voltage output unit 310 outputs a sensing region compensated data voltage to which a sensing region compensation value is applied, with the subpixels of the horizontal line on which no sensing is performed (S706).

That is, the data voltage output unit 310 changes the sensing region compensated image data transmitted from the controller 400 to a sensing region compensated data voltage, and outputs the sensed region compensated data voltage as a data line.

The present invention is summarized as follows.

The present invention is intended to improve the BlockDim in which the frame emission retention time between vertical blocks is different due to the difference of the sensing lines of the previous / current / next frames in the random progressive sensing.

To this end, in order to predict the frame emission retention time between blocks of the current frame by using the information of the previous / current / next sensing lines, and to correct the difference in luminance according to the emission sustaining time, That is, a sensing area compensation value is given.

Here, the final luminance between blocks = emission sustaining time X can be expressed by a weight.

In this case, each Scale (weight value) can be divided into three types by a combination of Active Time and Blank TIME as described above.

The final output compares the Sensing Line of the previous / current / next frame, applies the Scale value to the Block Status, and the formula for obtaining the final output is as follows.

 It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: panel 200: gate driver
300: Data driver 400: Timing controller
110: subpixel 120: unit pixel
410: Calculator 420: Control signal generator
430: Data sorting unit 440: Output unit
450: storage unit 310: data voltage output unit
320: sensing unit

Claims (10)

A panel having subpixels along imaginary horizontal lines corresponding to gate lines;
A sensing unit for performing sensing for external compensation on a randomly selected horizontal line among the horizontal lines to collect sensing data;
Calculating an external compensation value by using the sensing data to determine a characteristic change of each subpixel and using the sensing area compensation values corresponding to the areas set according to the horizontal line on which the sensing is performed, Sensing area compensation image data;
A data driver for outputting a sensing region compensated data voltage corresponding to the sensing region compensated image data to a data line formed on the panel; And
And a gate driver sequentially outputting gate pulses to the gate lines provided in the panel,
Wherein the sensing region compensation value is different for each of the regions. The method according to claim 1,
The regions may be,
Is arranged at the upper end of the horizontal line where sensing is performed in the current frame period and is disposed at the upper end of the sensing line in which sensing is performed in the next frame period or is arranged at the lower end of the horizontal line in which sensing is performed in the current frame period, A first region disposed at a lower end of a horizontal line where sensing is performed in a period,
A second region disposed at the lower end of the horizontal line where the sensing is performed in the current frame period and disposed at the upper end of the horizontal line where the sensing is performed in the next frame period,
And a third region disposed at the top of a horizontal line where sensing is performed in the current frame period and disposed at a lower end of a horizontal line where sensing is performed in the next frame period. The method according to claim 1,
Wherein,
And selects a horizontal line to perform sensing for external compensation in each frame period in accordance with a randomly preset sequence. The method according to claim 1,
Wherein,
The input image data is converted into the sensing area compensated image data by using the sensing area compensation value corresponding to the area, when the input image data is received, Organic light emitting display. The method according to claim 1,
Wherein,
And a control unit configured to determine an area corresponding to the input image data among the areas and output an external compensation value corresponding to a sensing area compensation value corresponding to the area and a subpixel to which the input image data is to be output To convert the input image data into the sensing area compensated image data,
Wherein the data driver outputs a sensing region compensated data voltage corresponding to the sensed region compensated image data to a data line formed in the panel for every one horizontal period. The method according to claim 1,
Wherein the sensing region compensation values applied to the subpixels included in one of the regions are the same. The method according to claim 1,
The sensing region compensation values applied to the subpixels included in any one of the regions may include at least one of
A reference sensing region compensation value commonly applied to all subpixels provided in any one of the regions, and
And an auxiliary sensing area compensation value that is changed according to at least one of a color and a gray of input image data corresponding to the subpixels provided in any one of the areas. The method according to claim 1,
Wherein the sensing unit performs sensing at a blanking time at which a gate pulse output to one of the gate lines during one frame period in which the gate pulse is output to all of the gate lines is delayed to output no video signal To the organic light emitting display device. The method according to claim 1,
The gate driver includes:
And delays the gate pulse output to the gate line corresponding to the horizontal line on which the sensing is performed until the sensing is completed. 3. The method of claim 2,
When the sensing region compensation value applied to the subpixels provided in the first region has a value that does not change the luminance of the subpixels provided in the first region, the sensing region compensation value is applied to the subpixels provided in the second region Wherein the sensing region compensation value has a value for increasing the luminance of the subpixels provided in the second region, and the sensing region compensation value applied to the subpixels provided in the third region is a value And a value that reduces the luminance of the subpixels.

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