KR102453947B1 - Organic light emitting diode and method for driving the same - Google Patents

Abstract

The present invention relates to an organic light emitting diode display that minimizes waste of power consumption and a delay time that occurs when the organic light emitting display is turned on in sensing characteristics of a light emitting device, and a driving method thereof. An organic light emitting diode display according to the present invention includes a display panel arranged in a matrix form including a light emitting element and a pixel circuit for driving the same, and a panel driver driving the display panel.
When the display panel is turned off, the panel driver generates first sensing data that senses characteristics of each light emitting device provided in pixels positioned from a first horizontal line to an N-th horizontal line (N is a natural number). When the display panel and the panel driver are turned on in the first sensing mode for storing, characteristics of each light emitting device provided in pixels located from the Nk (k is a natural number less than N) horizontal line to the last horizontal line After operating in the second sensing mode for generating the second sensing data sensed by and generating third sensing data reflecting the temperature error rate in the first sensing data from the first horizontal line to the Nk-th horizontal line, and storing the generated third sensing data together with the second sensing data.

Description

Organic light emitting display device and driving method thereof

The present invention relates to an organic light emitting display device and a driving method thereof, and more particularly, to an organic light emitting display device capable of greatly reducing a sensing time recognized by a user while minimizing a sensing error rate of a light emitting device due to temperature, and a driving method thereof .

A video display device that implements various information on a screen is a key technology in the information and communication era, which is developing in the direction of thinner, lighter, portable and high-performance. Accordingly, as a flat panel display capable of reducing weight and volume, which are disadvantages of a cathode ray tube (CRT), an organic light emitting display device that displays an image by controlling the emission amount of an organic light emitting layer is in the spotlight.

In an organic light emitting diode display, a plurality of pixels are arranged in a matrix to display an image. Here, each pixel includes a pixel driving circuit composed of a light emitting element and a plurality of transistors independently driving the light emitting element.

In a conventional organic light emitting diode display, a light emitting element deteriorates over time. That is, the current-voltage (I-V) characteristics of the light emitting device deteriorate over time. Accordingly, the driving voltage of the light emitting device gradually increases, and accordingly, the luminance of the light emitting device decreases when the same voltage is applied, and luminance non-uniformity occurs for each pixel.

In order to solve the above problem, a technique for sensing the operating point or threshold voltage of the light emitting device and compensating for deterioration of the light emitting device is proposed using compensation data according to a change in the characteristics of the light emitting device due to the deterioration. became However, the value of the sensed data varies greatly depending on the temperature. Therefore, in order to compensate for the deterioration of the light emitting device, it is essential to remove the effect of temperature from the sensing data.

Conventionally, in order to remove the effect of temperature from the sensing data, the user senses the light emitting device after a predetermined time after the display device is turned off, or by sensing the characteristics of the light emitting device after the display device is turned on. The effect of temperature was removed from the data.

In order to sense the characteristics of the light emitting device after a predetermined time after the display device is turned off, a minimum amount of power must be supplied to the display device until the sensing time. When the power of the display device is completely cut off, for example, is disconnected from the power source, there is a problem in that the sensing of the light emitting device is impossible.

In addition, when the light emitting device is sensed after the display device is turned on, a delay time in which the display device is not turned on occurs during a period of sensing the light emitting device of all pixels, and the light emitting device emits light due to the sensing of the light emitting device Therefore, there is a problem that the horizontal line of the horizontal line unit is recognized by the user.

The present invention has been devised to solve the above problems, and provides an organic light emitting display device capable of sensing characteristics of a light emitting device and a driving method thereof so as to minimize power consumption waste and a delay time occurring when the organic light emitting display device is turned on. Make it a task you want to solve.

In order to solve the above problems, an organic light emitting display device according to the present invention includes a display panel arranged in a matrix form including a light emitting element and a pixel circuit for driving the same, and driving the display panel, and the characteristics of each light emitting element and a panel driver that calculates the sensed data sensed, generates compensation data for compensating for deterioration of the light emitting device by using this, and compensates and outputs input image data using the compensation data.

In this case, the panel driver includes a gate driver, a data driver, a timing controller, a set unit, and a timer.

The timing controller generates and stores first sensing data sensing characteristics of light emitting devices up to an N (N is a natural number)-th horizontal line in a first sensing mode driven immediately before turning off the display panel and the panel driver, and then displays When the panel and the panel driver are turned on, second sensing data sensing the characteristics of the light emitting device from the N-k (k is a natural number less than N)-th horizontal line to the last horizontal line is generated and stored, and then the N-k-th horizontal line An error detection unit that calculates a temperature error rate by comparing the first sensing data and the second sensing data from to the N-th horizontal line, generates third sensing data reflecting the temperature error rate in the first sensing data, and stores the second sensing data and data and a compensation data calculation unit for receiving the second and third sensing data and calculating compensation data corresponding to the deterioration value of the light emitting device corresponding thereto, and a compensation and output unit for applying and compensating the input image data and outputting it do.

The set unit controls the timing controller to input image data to the timing controller and perform first and second sensing mode operations.

The timer stores turn-off times of the display panel and the panel driver, determines the time elapsed from the turn-off time when the display panel and the panel driver are turned on, and supplies time information to the set unit. The set unit analyzes the time information and, when the display panel is turned on without a predetermined cooling time after the first sensing mode, postpones the operation of the second sensing mode to a time when the next display panel and the panel driver are turned on.

In this case, in the pixel circuit, source/drain electrodes are connected between a high potential voltage source and a low potential voltage source, a driving transistor connected in series with the light emitting device, and a gate electrode of the data line and the driving transistor in response to a gate signal supplied to the gate line A switching transistor connecting the first node connected to each other and sensing connecting the reference line and the second node connected to the source electrode of the driving transistor to each other in response to a sensing signal from a sensing line parallel to the gate line a transistor and a storage capacitor coupled between the first and second nodes.

In the method of driving an organic light emitting display device according to the present invention, immediately before the display panel and the panel driver are turned off, each pixel provided in the first horizontal line to the Nth horizontal line (N is a natural number) Operating in a first sensing mode for generating and storing first sensing data sensing characteristics of a light emitting device, when the display panel and the panel driver are turned on, from the N-k-th horizontal line (k is a natural number less than N) Operating in the second sensing mode for generating second sensing data by sensing the characteristics of each light emitting device provided in the pixels positioned up to the last horizontal line, the first from the N-k-th horizontal line to the N-th horizontal line and calculating a temperature error rate by comparing the second sensing data, generating third sensing data reflecting the temperature error rate in the first sensing data, and storing the second and third sensing data; generating and storing compensation data for compensating for deterioration of the light emitting device using third sensing data; and compensating and outputting image data input from a set using the compensation data.

The organic light emitting diode display according to the present invention senses characteristics of light emitting devices positioned on horizontal lines of many pixels when turned off, and then, when the power of the organic light emitting display device is turned on, characteristics of light emitting devices positioned on relatively few horizontal lines of pixels will sense Nevertheless, the organic light emitting diode display according to the present invention can sense the characteristics of the light emitting element and then remove an error in the sensed data due to heat generation, thereby accurately sensing the characteristics of the light emitting element.

The organic light emitting diode display according to the present invention senses only a small number of horizontal lines during turn-on, thereby reducing the turn-on time of the display device. In addition, when only a small number of horizontal lines are sensed during turn-on as described above, the probability of recognizing a horizontal line phenomenon due to sensing to the user is greatly reduced.

In addition, the organic light emitting display device according to the present invention maintains standby power for a period in which the display panel is sufficiently cooled even after the power of the conventional display panel is turned off, and then senses the characteristics of the light emitting device after the cooling time. It has the effect of accurately sensing the characteristics of the light emitting device while reducing standby power consumption compared to the device.

1 and 2 are exemplary views for explaining an organic light emitting diode display according to the present invention.
3 is an exemplary view for explaining the effect of shortening the sensing period of the organic light emitting diode display according to the present invention.
4 is an exemplary view for explaining a method of driving an organic light emitting display device according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Like reference numerals refer to substantially identical elements throughout. In the following description, when it is determined that a detailed description of a technology or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, the component names used in the following description are selected in consideration of the ease of writing the specification, and may be different from the component names of the actual product.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary and are not limited to the matters disclosed in the present invention.

1 and 2 are exemplary views for explaining an organic light emitting display device according to the present invention.

An organic light emitting diode display according to an embodiment of the present invention includes a display panel 100 and a panel driver.

The panel driver includes a data driver 200 , a gate driver 300 , a timing controller 400 , a memory 500 , a set unit 600 , and a timer 700 .

The display panel 100 includes a plurality of gate lines GL and data lines DL, and pixels P arranged in a matrix form in a region where the gate lines GL and the data lines DL intersect each other. ), a plurality of sensing lines SL positioned parallel to the gate line GL, a plurality of driving power lines PL and a plurality of reference lines RL positioned parallel to the data line DL. includes

The plurality of pixels P includes a light emitting device OLED and a pixel driving circuit PC for emitting light from the light emitting device OLED. The pixel driving circuit includes a driving transistor DT, a switching transistor ST1, a sensing transistor ST2, and a storage capacitor Cst. In the exemplary embodiment of the present invention, a pixel driving circuit having a 3T1C structure is described as an example, but the present invention is not limited thereto, and a person skilled in the art may change the structure as needed.

The switching transistor ST1 has a gate electrode connected to the gate line GL of each pixel P, a drain electrode connected to the data line DL, and a first node , which is a first terminal of the storage capacitor Cst. A source electrode is connected to n1).

Accordingly, the switching transistor ST1 supplies the data voltage Vdata from the data line DL to the first node n1 in response to the scan signal from the gate line GL of each pixel P.

The driving transistor DT has a gate electrode connected to the first node n1 , a drain electrode connected to a power line PL supplying the EVDD voltage EVDD, and a source electrode connected to the anode electrode of the light emitting device OLED. is connected

Accordingly, the driving transistor DT controls the amount of current flowing through the light emitting device OLED according to a voltage applied between its source-gate voltage Vgs.

The sensing transistor ST2 has a gate electrode connected to the sensing line SL of each pixel P, a source electrode connected to the second node n2 , and a drain electrode connected to the third node n3 .

Accordingly, the sensing transistor ST supplies the precharge voltage from the reference line RL to the second node n2 in response to the sensing signal from the sensing line SL, or improves the characteristics of the light emitting device OLED. The indicated voltage is supplied to the reference line RL. A reference capacitor C _Ref for charging a voltage representing characteristics of the light emitting device OLED may be further provided on the reference line RL.

The storage capacitor Cst has a first terminal connected to a first node n1 and a second terminal connected to a second node n2 . The storage capacitor Cst charges a difference voltage between voltages supplied to each of the first and second nodes n1 and n2 and supplies it as the driving voltage Vgs of the driving transistor DT. For example, the storage capacitor Cst charges a difference voltage between the data voltage Vdata supplied to each of the first and second nodes n1 and n2 and the precharge Vpre.

The gate driver 300 supplies a gate signal to the gate line GL and a sensing signal to the sensing line SL.

The timing controller 400 controls operations of the data driver 200 and the gate driver 300 . In more detail, the timing controller 400 displays an image by operating the data driver 200 and the gate driver 300 in a driving mode. Also, the timing controller 400 operates the data driver 200 and the gate driver 300 in a sensing mode to sense a change in characteristics of the light emitting device OLED and the driving transistor DT of each pixel.

The timing controller 400 generates a gate control signal GCS and a data control signal DCS using a timing synchronization signal input from the set unit 600 . Here, the timing synchronization signal may include a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE, and a clock signal DCLK. The set unit 600 supplies the timing synchronization signal and the image data Vdata to the timing controller 400 .

The timing controller 400 may perform a sensing mode operation under the control of the set unit 600 . In this case, the timing controller 400 performs the first sensing mode operation immediately before turning off the display device, that is, the display panel 100 and the panel driver, and performs the second sensing mode operation when the display device is powered on.

The timing controller 400 operates the data driver 200 and the gate driver 300 in the sensing mode in the first and second sensing modes.

To this end, the data driver 200 includes a sensing unit 210 . The sensing unit 210 senses a change in characteristics of the light emitting device OLED. Thereafter, the sensing unit 210 outputs sensing data obtained by digitally converting the characteristics of the light emitting device OELD to the timing controller 400 .

The timing controller 400 generates first sensing data by sensing characteristics of a light emitting device positioned on an N-th (N is a natural number) horizontal line from the first horizontal line when the display device is powered off, and the display device is powered on. At a point in time, second sensing data sensing the characteristics of the light emitting device positioned in the last horizontal line from the N-k (k is a natural number less than N)-th horizontal line is sensed, and then the first sensing data from the N-k-th horizontal line to the N-th horizontal line and calculating a temperature error rate by comparing the second sensing data, and generating third sensing data obtained by correcting the first sensing data by applying the temperature error rate to the first sensing data.

At this time, since the temperature error rate is applied to the second sensing data itself from the N-k-th horizontal line to the N-th horizontal line, the third sensing data is generated by correcting the first sensing data from the first horizontal line to the N-k-th horizontal line. It is preferable to do

Then, the timing controller 400 calculates compensation data of the light emitting device using the second and third sensing data, and then corrects the image data input from the set unit 600 and outputs it to the data driver 200 .

To this end, the timing controller 400 includes an error detection unit 410 , a compensation data calculation unit 420 , and a compensation and output unit 430 .

The error detection unit 410 inputs first sensing data from the sensing unit 210 by sensing the characteristics of the light emitting device OLED provided in each pixel located from the first horizontal line to the N (N is a natural number)-th horizontal line. received and stored in the memory 500 . Thereafter, in the second sensing mode performed when the display device is powered on, the error detection unit 410 is configured for each pixel positioned from the N-k (k is a natural number less than N) horizontal line to the last horizontal line from the sensing unit 210 . The second sensing data for sensing the characteristics of the provided light emitting device (OLED) is received. Then, the temperature error rate (α) is calculated by calculating the difference between the first sensed data from the N-k-th horizontal line to the N-th horizontal line and the second sensed data from the N-k-th horizontal line to the N-th horizontal line. and third sensing data corrected by applying the temperature error rate α to the first sensing data, and the second sensing data are stored in the memory 500 .

In this case, the value of k may be variously changed according to design. However, since the number of overlapped and sensed horizontal lines increases as the value of k increases, it is preferable that k has a value between 10 and 100. In this case, the temperature error rate α may be determined as an average value of the temperature error rates in each of the k sensing lines.

The compensation data calculator 420 calculates compensation data corresponding to deterioration values of the light emitting device corresponding to the second and third sensing data input from the memory 500 , and stores the compensation data back into the memory 500 . Save. For example, the compensation circuit unit 410 uses a look-up table indicating driving voltage values of the light emitting device OLED corresponding to the operating point or threshold voltage value of the light emitting device included in the sensed data, and the like to use the light emitting device. may calculate the driving voltage of , and generate compensation data corresponding to the increase in the driving voltage of the light emitting device, but is not limited thereto.

The compensation/output unit 430 compensates the image data input from the set unit 600 using the compensation data, and outputs the compensated image data to the data driver 200 .

The data driver 200 includes a digital-to-analog converter DAC, converts the corrected image data into an analog data voltage, and outputs the converted image data to the data lines DL.

The organic light emitting diode display according to the present invention further includes a timer 700 . The timer 700 records the time when the power of the organic light emitting diode display device is turned off, calculates a time from when the power is turned on, and outputs the result to the set unit 600 .

The set unit 600 determines whether the light emitting device OLED of the display panel 100 has passed through a sufficient cooling time after driving in the first sensing mode through time information from the timer 700 . do. In this case, the set unit 600 sets a reference time, and determines whether more than a reference time has elapsed from when the power of the organic light emitting diode display device is turned off to being turned on. In this case, it is preferable that the reference time is at least 1 hour or longer.

The set unit 600 controls the timing controller 400 to enter the second sensing mode only when a reference time elapses from the time when the power of the organic light emitting diode display is turned off after driving in the first sensing mode. On the other hand, when the reference time has not elapsed, the set unit 600 controls the timing controller 400 to drive in the display mode without entering the second sensing mode, and instead sets the second sensing mode entry time to the next organic light emission. It is postponed to the turn-on time of the display device.

3 is an exemplary view for explaining the effect of shortening the sensing period of the organic light emitting diode display according to the present invention.

3 , the organic light emitting diode display according to the present invention senses characteristics of each light emitting element (OLED) positioned in pixels positioned from the first horizontal line to the N-th horizontal line when the power is turned off. Then, when the power of the organic light emitting diode display is turned on, sensing is performed only from the N-k-th horizontal line slightly above the N-th horizontal line to the last horizontal line.

Here, the value of N may vary depending on the design. At this time, when a circuit with a large amount of heat, such as the data driver 400 , is adjacent to the display panel 100 , the temperature of adjacent pixels is greatly increased due to heat generated by the data driver 400 , so that the temperature error rate calculation cannot be performed accurately. there is a fear that it will not Accordingly, the N value is preferably determined as a value corresponding to a horizontal line that is not affected by heat generated by the data driver 400 among pixels located on each horizontal line of the display panel 100 . In other words, as a component having a large amount of heat, such as the data driver 400, is positioned further away from the display panel 100, the N value may further increase.

For example, when the data driver 400 is located directly under the display panel 100 , the N value may correspond to about 70% of all horizontal pixel lines of the display panel 100 . For example, assuming that all horizontal pixel lines of the display panel 100 are 1920 lines, the N value may be about 1300.

In addition, if it is assumed that the data driver 400 is spaced apart from the display panel 100 so that there is little effect due to heat generation on the display panel 100 , the N value is 90 out of all horizontal pixel lines of the display panel 100 . % or more. For example, assuming that all pixel horizontal lines are 1920 lines, in this case, the value of N may be about 1700.

In general, it takes several minutes to sense the characteristics of all light emitting devices positioned in the horizontal line of all pixels of the display panel 100 , and from the point of view of the user, the display device cannot be turned on for a very long time. This happens. On the other hand, since the organic light emitting diode display according to the present invention senses only light emitting devices positioned on some horizontal lines at the turn-on time of the organic light emitting display device, the sensing time is reduced to less than a few seconds to less than one minute.

In other words, the organic light emitting diode display according to the present invention senses characteristics of light emitting devices positioned in a relatively large number of horizontal pixel lines when power is turned off, and then, when the power of the organic light emitting display device is turned on, a relatively small number of horizontal pixels are sensed. After sensing the characteristic of the light emitting device located in the line, an error due to temperature is removed from the characteristic of the light emitting device sensed when the light emitting device is turned off. Accordingly, the organic light emitting diode display according to the present invention senses only a small number of horizontal lines during turn-on, thereby reducing the turn-on time of the display device. In addition, when only a small number of horizontal lines are sensed during turn-on as described above, the probability of recognizing a horizontal line phenomenon due to sensing to the user is greatly reduced.

In addition, the organic light emitting display device according to the present invention maintains standby power for a period in which the display panel is sufficiently cooled even after the power of the conventional display panel is turned off, and then senses the characteristics of the light emitting device after the cooling time. It has the effect of accurately sensing the characteristics of the light emitting device while reducing standby power consumption compared to the device.

Hereinafter, a method of driving an organic light emitting diode display according to the present invention will be described.

4 is a flowchart illustrating a method of driving an organic light emitting diode display according to the present invention.

When the organic light emitting diode display is turned off, the timing controller 400 operates the data driver 200 and the gate driver 300 in the first sensing mode.

Here, the characteristic of the light emitting device OLED may be an operating point or a threshold voltage of the light emitting device OLED, but is not limited thereto.

The method of sensing the operating point of the light emitting device (OLED) is disclosed in Korean Patent Application Laid-Open No. 10-2016-0033957, etc., as disclosed in Korean Patent Application Laid-Open No. 10-2016-0033957, etc., during the initialization period, the reference line RL and The reference line RL and the second node n2 are initialized by supplying a pre-charging voltage to the source electrode of the driving transistor DT, and the switching transistor ST1 is turned on during the light emission period to provide data to the data line DL. The voltage Vdata is supplied and the difference voltage between the data voltage Vdata and the precharging voltage Vpre is stored in the storage capacitor Cst, and then the driving transistor DT is turned on by the stored difference voltage, The driving transistor DT supplies a driving current determined by the stored differential voltage to the light emitting device OLED, so that the light emitting device OLED responds to the driving current flowing from the high potential voltage source EVDD to the low potential voltage source EVSS. light proportionally.

Then, during the sensing period, the sensing transistor is turned on to charge the sensing capacitor Cref provided in the reference line RL with the voltage stored in the second node n2, and the voltage charged in the sensing capacitor Cref. By reading , the voltage of the anode electrode may be sensed when the light emitting device OLED emits light, and the operating point of the light emitting device may be sensed through this, but is not limited thereto.

In the method of sensing the threshold voltage of the light emitting device, the light emitting device is subjected to the same initialization period and light emission period as when sensing the operating point of the light emitting device, and then, during the first sensing period, the sensing transistor is turned on to turn on the light emitting device. (OLED) stores the voltage of the anode electrode, senses the voltage of the anode electrode when the light emitting device emits light to sense the operating point of the light emitting device, then turns off the driving transistor, and turns off the reference through the turned-on sensing transistor The threshold voltage may be sensed when the light emitting device OLED does not emit light by discharging the line, but is not limited thereto.

In the first sensing period, the sensing unit 210 senses characteristics such as an operating point or a threshold voltage of a light emitting device (OLED) provided in each pixel positioned from the first horizontal line to the N-th horizontal line, and the sensing The first sensing data obtained by digital conversion of the obtained characteristic is output to the error detection unit 410 .

The error detection unit 410 receives the first sensing data from the sensing unit 210 and stores it in a memory.

When the organic light emitting diode display is next turned on, the timing controller 400 operates the data driver 200 and the gate driver 300 in the second sensing mode under the control of the set unit 600 . At this time, when a sufficient cooling time has not elapsed since the turn-on time is the previous turn-off time, the set unit 600 postpones the operation of the second sensing mode to the next turn-on time. To this end, the timer 700 records the turn-off time of the organic light emitting diode display, and then outputs time information calculated by calculating the time from the turn-off time at the turn-on time to the set unit 600 . Thereafter, the set unit 600 determines whether the light emitting device OLED of the display panel 100 has undergone a sufficient cooling time after the first sensing mode through the time information. For example, the set unit 600 sets a reference time, determines whether more than a reference time has elapsed from when the power of the organic light emitting diode display device is turned off to turn on, and performs timing only when the reference time elapses. The controller 400 controls the timing controller 400 to enter the second sensing mode.

When the reference time has not elapsed, the set unit 600 controls the timing controller 400 to enter the display mode without entering the second sensing mode, and sets the second sensing mode entry time of the next organic light emitting display device. It is postponed to the point of turn on.

The sensing unit 210 receives second sensing data sensing the characteristics of the light emitting device (OLED) provided in each pixel positioned from the N-k-th horizontal line to the last horizontal line, and receives the second sensing data from the N-k-th horizontal line to the N-th horizontal line. The temperature error rate (α) is calculated by calculating a difference value between the first sensed data up to and the second sensed data from the N-k-th horizontal line to the N-th horizontal line, and the first sensed data is combined with the temperature error rate (α). ) and the corrected third sensing data and the second sensing data are stored in the memory 500 . In this case, the value of k may be variously changed according to design. However, since the number of overlapped and sensed horizontal lines increases as the value of k increases, it is preferable that k has a value between 10 and 100. In this case, the temperature error rate α may be determined as an average value of the temperature error rates in each of the k sensing lines.

The compensation data calculator 420 calculates a deterioration value of the light emitting device corresponding to the second and third sensing data input from the memory 500 , that is, compensation data corresponding to a shift in the operating point or threshold voltage of the light emitting device. and stores the compensation data in the memory 500 again. For example, the compensation circuit unit 410 uses a look-up table indicating driving voltage values of the light emitting device OLED corresponding to the operating point or threshold voltage value of the light emitting device included in the sensed data, and the like to use the light emitting device. may calculate the driving voltage of , and generate compensation data corresponding to the increase in the driving voltage of the light emitting device, but is not limited thereto.

The compensation/output unit 430 compensates the image data input from the set unit 600 using the compensation data, and outputs the compensated image data to the data driver 200 .

The data driver 200 includes a digital-to-analog converter DAC, converts the corrected image data into an analog data voltage, and outputs the converted image data to the data lines DL.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is known in the art to which the present invention pertains that various substitutions, modifications and changes are possible without departing from the technical spirit of the present invention. It will be clear to those who have the knowledge of

100: display panel 200: data driver
300: gate driver 400: timing controller
500: memory 600: set unit
700: timer 210: sensing unit
410: error detection unit 420: compensation data calculation unit
430: compensation, output unit

Claims (12)

a display panel including a plurality of pixels including a light emitting device and a pixel circuit for driving the light emitting device, wherein the pixels are positioned in a matrix form in a region defined by crossing a plurality of gate lines and data lines; and
a panel driver for driving the display panel;
The panel driver,
Operates in the first sensing mode immediately before the display panel and the panel driver are turned off,
In the first sensing mode, the panel driver generates and stores first sensing data sensing a characteristic of each light emitting device provided in pixels located from a first horizontal line to an N-th horizontal line (N is a natural number), and ,
When the display panel is turned on, it operates in the second sensing mode,
In the second sensing mode, the panel driver generates second sensing data by sensing the characteristics of each light emitting device provided in pixels positioned from the Nk (k is a natural number less than N)-th horizontal line to the last horizontal line. Next, a difference value between the first sensed data and the second sensed data from the Nk-th horizontal line to the N-th horizontal line is defined as a temperature error rate, and the first sensing from the first horizontal line to the Nk-th horizontal line An organic light emitting diode display for generating third sensing data by reflecting the temperature error rate in data and storing the generated third sensing data together with the second sensing data. The method of claim 1,
The panel driver,
a gate driver that supplies a gate signal to the gate line and is disposed parallel to the gate line and supplies a sensing signal to a sensing line that supplies a sensing signal to each pixel;
a data driver driving the data lines and sensing characteristics of the light emitting device through a reference line that reads the voltage stored in each pixel in the first and second sensing modes;
Comparing the first and second sensing data from the Nk-th horizontal line to the N-th horizontal line, calculating the temperature error rate, and generating the third sensing data reflecting the temperature error rate in the first sensing data, a timing controller for generating compensation data using the second and third sensing data, storing the compensation data, and compensating and outputting the input image data using the compensation data;
and a memory configured to store the first to third sensing data and the compensation data. 3. The method of claim 2,
The data driver is
and a sensing unit sensing characteristics of the light emitting device of each pixel to generate first sensing data and the second sensing data, and outputting the first sensing data and the second sensing data. 3. The method of claim 2,
The timing controller is
The first sensing data is received and stored in the first sensing mode, the second sensing data is received in the second sensing mode, and the first sensing data from the Nk-th horizontal line to the N-th horizontal line and an error detection unit for calculating a temperature error rate by calculating a difference value between the second sensed data and the second sensed data, and then generating third sensing data in which the temperature error rate is reflected in the first sensed data;
a compensation data calculating unit receiving the second and third sensing data, calculating and outputting the compensation data corresponding to the deterioration value of the light emitting device corresponding thereto;
An organic light emitting diode display comprising: a compensation and an output unit for outputting input image data by applying and compensating for the compensation data. 3. The method of claim 2,
A set unit for inputting the image data to the timing controller and controlling the timing controller to perform the first and second sensing mode operations; and a turn-off time of the display panel; A timer for outputting time information to the set unit by determining a time elapsed from the turn-off time of the display panel at the turn-on time;
The set unit analyzes the time information and, when the display panel is turned on without a predetermined cooling time after the first sensing mode, sets the second sensing mode operation as a time point at which the display panel is next turned on. Smoked organic light emitting display device. 3. The method of claim 2,
The pixel circuit is
a driving transistor connected in series with the light emitting device between a high potential voltage source and a low potential voltage source;
a switching transistor connecting the data line and a first node connected to a gate of the driving transistor to each other in response to a gate signal supplied to the gate line;
a sensing transistor for connecting a second node connected to a source electrode of the driving transistor and a third node connected to the reference line to each other in response to a sensing signal supplied to the sensing line;
and a storage capacitor connected between the first and second nodes. The method of claim 1,
The characteristic of the light emitting device is an operating point or a threshold voltage of the light emitting device. The method of claim 1,
The temperature error rate is an average of differences between first and second sensing data from the Nk-th horizontal line to the N-th horizontal line. a display panel comprising a plurality of pixels including a light emitting device and a pixel circuit for driving the same, wherein the pixels are positioned in a matrix form in a region defined by crossing a plurality of gate lines and data lines; A method of driving an organic light emitting diode display including a panel driving unit for driving, the method comprising:
Immediately before the display panel and the panel driver are turned off, first sensing data is generated by sensing the characteristic of each light emitting device provided in pixels positioned from the first horizontal line to the N-th horizontal line (N is a natural number) operating in the first sensing mode to store
When the display panel and the panel driver are turned on, second sensing data is generated by sensing the characteristic of each light emitting device included in the pixels positioned from the Nk-th horizontal line (k is a natural number less than N) to the last horizontal line operating in a second sensing mode,
Comparing the first and second sensing data from the Nk-th horizontal line to the N-th horizontal line to calculate a temperature error rate, generate third sensing data reflecting the temperature error rate in the first sensing data, and storing the second and third sensing data;
generating and storing compensation data for compensating for deterioration of the light emitting device using the second and third sensing data;
and compensating and outputting image data input from a set using the compensation data. 10. The method of claim 9,
The panel driver compares a turn-off time of the display panel and the panel driver with a subsequent turn-on time, and performs the second sensing mode operation only when the turn-on time elapses more than a reference time from the turn-off time. A method of driving a display device. 10. The method of claim 9,
The characteristic of the light emitting device is an operating point or a threshold voltage of the light emitting device. 10. The method of claim 9,
The temperature error rate is an average of differences between first and second sensing data from the Nk-th horizontal line to the N-th horizontal line.

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