KR20180007822A - Degradation Sensing Method of Organic Light Emitting Display - Google Patents

Abstract

The present invention relates to a deterioration sensing method of an organic light emitting display device which has a plurality of unit pixels including subpixels of different colors and a plurality of sensing units for sensing the electrical characteristics of the subpixels. The deterioration sensing method includes a step of selecting subpixels one by one from the unit pixels and electrically connecting them to the sensing units; a step of sensing the electrical characteristics of the subpixels connected to the sensing units simultaneously. The simultaneously-sensed subpixels have different colors between horizontally neighboring unit pixels. It is possible to minimize the perception of horizontal pixel lines as bright lines.

Description

[0001] The present invention relates to a method of sensing a degradation of an organic light-

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light emitting diode (OLED) display, and more particularly, to a deterioration sensing method for a subpixel of an OLED display.

The active matrix type organic light emitting display device includes an organic light emitting diode (organic light emitting diode) (hereinafter referred to as "organic device") that emits light by itself, has a high response speed, and has a large luminous efficiency, luminance, and viewing angle.

The organic device as a self-luminous device includes an anode electrode, a cathode electrode, and organic compound layers (HIL, HTL, EML, ETL, EIL) formed therebetween. The organic compound layer includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer EIL). When a driving voltage is applied to the anode electrode and the cathode electrode, holes passing through the HTL and electrons passing through the ETL are transferred to the EML to form excitons, Thereby generating visible light.

The organic light emitting display device arranges subpixels each including an OLED in a matrix form and controls the amount of emitted light of the OLED according to the gradation of the image data to adjust the luminance. Each of the subpixels includes a driving TFT (Thin Film Transistor) for controlling the pixel current flowing in the OLED according to the voltage applied between its gate electrode and the source electrode. The electrical characteristics of the OLED and the driving TFT may deteriorate with the elapse of the driving time, resulting in a difference in the sub-pixels. The electrical characteristic deviation between such subpixels is a main factor for lowering image quality.

(The threshold voltage of the driving TFT, the mobility of the driving TFT, and the threshold voltage of the OLED) in order to compensate the electrical characteristic deviation between the subpixels, and the sensing information corresponding to the external A compensation technique for modulating image data in a circuit is known.

In the case of the threshold voltage compensation of the OLED, the OLED driving voltage is programmed so that the OLED emits light, and the difference between the source node voltage of the driving TFT corresponding to the OLED driving voltage and the gate node voltage of the driving TFT corresponding to the data voltage, Source voltage Vgs of the gate-source voltage Vgs of the gate-source voltage Vgs. In order to detect the threshold voltage of the OLED, a method of charging the sensing line with a charge can be used. The gate-source voltage (Vgs) of the driving TFT and the sensing line charging speed and the sensing voltage are different according to the degree of deterioration of the OLED. The compensation method of the threshold voltage of the OLED differs according to the sensing voltage.

In the case of the threshold voltage compensation of the conventional OLED, sequential sensing is performed in units of horizontal pixel lines (L1 to L2160) of the display panel as shown in FIG. In particular, the R, W, G and B subpixels arranged in the same horizontal pixel line can be sequentially sensed in the same color unit. For example, as shown in FIG. 1, the subpixels arranged in each horizontal pixel line (L1 to L2160) may be sequentially sensed in the order of R, W, G, Here, the R subpixel is a red display subpixel, the W subpixel is a white display subpixel, the G subpixel is a green display subpixel, and the B subpixel is a blue display subpixel. The R, W, G, and B subpixels may constitute one unit pixel UP.

According to the sequential sensing method for each color described above, there is a problem that the horizontal pixel line being sensed is recognized as a bright line as shown in FIG. This is because the OLED emits light during programming of the OLED driving voltage. In particular, when the sub-pixels of a certain color, for example, W sub-pixels having a relatively large amount of light emission in the horizontal pixel line are simultaneously sensed, the degree of visibility to the bright line increases.

It is therefore an object of the present invention to provide a deterioration sensing method of an organic light emitting display device which can minimize the recognition of a horizontal pixel line during a sensing by a bright line.

According to an aspect of the present invention, there is provided a method for sensing degradation of an organic light emitting display device including a plurality of unit pixels each including sub-pixels of different colors and a plurality of sensing units for sensing electrical characteristics of the sub- Selecting one of the subpixels in the unit pixels and electrically connecting the subpixels to the sensing units; and sensing the electrical characteristics of the subpixels connected to the sensing units at the same time, The pixels have different colors between horizontally adjacent unit pixels.

In the present invention, all the subpixels arranged in one horizontal pixel line are sensed once by K (K is the number of subpixels constituting a unit pixel) sensing operation.

In the present invention, the horizontal color order of the subpixels simultaneously sensed by the first sensing operation is different from the horizontal color order of the subpixels simultaneously sensed by the second sensing operation subsequent to the first sensing operation.

In the present invention, all the subpixels of the first horizontal pixel line are sensed once by the K sequential sensing operations, and then all subpixels of the second horizontal pixel line neighboring the first horizontal pixel line are sensed by the K And are sensed once by the sequential sensing operation of the conference.

In the present invention, some of the sub-pixels of the first horizontal pixel line are simultaneously sensed by a first sensing operation, and an Mth (M is an integer equal to or larger than 3) in which at least one horizontal pixel line exists between the first horizontal pixel line and the first horizontal pixel line. Some positive sub-pixels of the horizontal pixel line are simultaneously sensed by the second sensing operation subsequent to the first.

In the present invention, the sensing operation is performed for a predetermined period during which no image data is written to the subpixels.

In the present invention, the predetermined period may be a power-on sequence period immediately after application of system power necessary for operation of the OLED display device, or a power-off sequence period immediately after the system power is released, Indicating a vertical blanking period arranged between vertically active periods.

In the present invention, the electrical characteristics of the subpixels are determined based on a threshold voltage of an OLED included in the subpixels, a threshold voltage of a driving TFT included in the subpixels, and a mobility of driving TFTs included in the subpixels And at least one of them.

The present invention can minimize the perception of the horizontal pixel line as a bright line during sensing by simultaneously sensing subpixels of all colors simultaneously, rather than sensing only the same color subpixels at the same time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a conventional deterioration sensing method of an organic light emitting display. FIG.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light emitting display.
3 is a view illustrating an organic light emitting display according to an embodiment of the present invention.
FIGS. 4 and 5 are views showing an example of connection of a sensing line and a sub-pixel. FIG.
FIGS. 6 and 7 are diagrams showing an example of a configuration of a pixel array and a data driver IC; FIG.
8 is a diagram for explaining a period during which degradation sensing of the present invention is performed;
9 is a view showing a degradation sensing method according to the first embodiment of the present invention.
10 is a view showing a degradation sensing method according to a second embodiment of the present invention.
11 is a view showing an exemplary configuration of a subpixel and a sensing unit to which the degradation sensing method of the present invention is applied.
12 is a diagram illustrating a method of sensing an OLED threshold voltage as a method for sensing degradation 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. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

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. Where the terms "comprises", "having", "done", and the like are used in this specification, other portions may 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.

Although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are used only to distinguish one component from another.

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, and technically various interlocking and driving are possible, 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.

First, a configuration of an OLED display to which the deterioration sensing method of the present invention is applied will be described with reference to FIGS. 3 to 8. FIG. FIG. 3 illustrates an organic light emitting display according to an embodiment of the present invention. 4 and 5 show an example of connection of a sensing line and a subpixel. 6 and 7 show an example of the configuration of the pixel array and the data driver IC. 8 is a view for explaining a period during which the deterioration sensing of the present invention is performed.

3 to 8, an OLED display according to an exemplary embodiment of the present invention includes a display panel 10, a timing controller 11, a data driving circuit 12, a gate driving circuit 13, 16).

A plurality of data lines and sensing lines 14A and 14B and a plurality of gate lines 15 are crossed on the display panel 10 and subpixels SP are arranged in a matrix form for each of the intersection areas . The gate lines 15 may include a plurality of first gate lines 15A to which a scan control signal is sequentially supplied and a plurality of second gate lines 15B to which a sensing control signal is sequentially supplied have.

The subpixels SP may include horizontally adjacent R subpixels for red display, W subpixel for white display, G subpixel for green display, and B subpixel for blue display, which are horizontally adjacent to each other as shown in Figs. 4 and 5 have. Each subpixel SP is connected to any one of the data lines 14A, to one of the sensing lines 14B and to one of the first gate lines 15A, to the second gate lines 15B Or the like. Each sub pixel SP is electrically connected to the data line 14A in response to a scan control signal input through the first gate lines 15A to generate a data voltage for sensing Vdata_SEN ( Or a black display data voltage (Vdata_black)), and output a sensing signal through the sensing line 14B. The sensing data voltage Vdata_SEN is selectively applied only to the subpixel to be sensed and the black display data voltage Vdata_black is applied to the non-sensing subpixel. In Figs. 4 and 5, Vpre represents an initialization voltage, and Vsen represents a sensing voltage.

The sensing line 14B of the present invention can be implemented as a sensing line independent structure or a sensing line shared structure.

According to the sensing line independent structure of FIGS. 4 and 6, the sensing line 14B can be independently connected to each horizontally adjacent subpixel. For example, R horizontally neighboring R subpixels, W subpixels, G subpixels, and B subpixels may be connected one to another to different sensing lines 14B.

5 and FIG. 7, the sensing line 14B is commonly connected to a plurality of sub-pixels R, W, G and B constituting one unit pixel UP . For example, the R subpixel, the W subpixel, the G subpixel, and the B subpixel forming the unit pixel UP adjacent to each other horizontally may share the same sensing line 14B. The sensing line shared structure can reduce the number of sensing lines 14B as compared with the sensing line independent structure, and it is easy to secure the aperture ratio of the display panel.

Each of the subpixels SP is supplied with a high potential driving voltage EVDD and a low potential driving voltage EVSS from a power supply not shown. The subpixel SP of the present invention may include an OLED and a driving TFT for external compensation. The TFTs constituting the subpixel SP may be implemented as a p-type or an n-type. In addition, the semiconductor layer of the TFTs constituting the subpixel SP may include amorphous silicon, polysilicon, or an oxide.

Each of the subpixels SP may operate differently at the time of the normal driving for the display image implementation and at the sensing operation for obtaining the sensing value. Sensing operation may be performed by one operation of the data driving circuit 12 and the gate driving circuit 13 under the control of the timing controller 11. [

The data driving circuit 12 includes at least one data driver IC (Integrated Circuit) (SDIC). The data driver IC (SDIC) includes a plurality of digital-to-analog converters (hereinafter referred to as DACs) 121 connected to each data line 14A, a plurality of sensing units 122 connected to the sensing lines 14B, A mux portion 123 for selectively connecting the sensing units 122 to an analog-to-digital converter (ADC), and a selection control signal is generated to sequentially turn on the switches SS1 to SSk of the mux portion 123 And a shift register 124 which is turned on.

The DAC of the data driver IC (SDIC) converts the image data (RGB) into the image display data voltage in accordance with the data timing control signal (DDC) applied from the timing controller 11 in the normal driving, Supply. On the other hand, the DAC of the data driver IC (SDIC) generates the sensing data voltage Vdata_SEN (or the black display data voltage Vdata_black) in accordance with the data timing control signal DDC applied from the timing controller 11, And supplies them to the data lines 14A.

Each sensing unit (SU) of the data driver IC (SDIC) can be connected to the sensing line 14B on a one-to-one basis. The number of the sensing lines 14B and the number of the sensing units SU in the sensing line shared structure shown in FIG. 5 is reduced as compared with the sensing line independent structure shown in FIG. The sensing line independent structure is more advantageous in improving the sensing accuracy, and the sensing line sharing structure is more advantageous in reducing the circuit design area and increasing the aperture ratio.

The sensing unit SU may be implemented as a voltage sensing type or a current sensing type. The sensing unit SU of the voltage sensing type acquires the accumulated voltage of the sensing line as the sensing voltage by using the sample and hold unit S / H as shown in FIG. On the other hand, the sensing unit SU of the current sensing type can convert the current flowing through the sensing line into the sensing voltage by using the current integrator.

The ADC of the data driver IC (SDIC) converts the sensing voltage input through the mux 123 into a digital sensing value SD and transmits the digital sensing value SD to the timing controller 11.

The gate driver circuit 13 generates a scan control signal and a sensing control signal based on the gate control signal GDC during the sensing operation. The gate drive circuit 13 sequentially supplies scan control signals to the first gate lines 15A and sequentially supplies the scan control signals to the second gate lines 15B in accordance with the sequential sensing method of FIG. . The gate drive circuit 13 randomly supplies a scan control signal to the first gate lines 15A corresponding to the random sensing method of FIG. 10 and randomly supplies a sensing control signal to the second gate lines 15B .

The timing controller 11 controls the operation of the data driving circuit 12 based on timing signals such as a vertical synchronizing signal Vsync, a horizontal synchronizing signal Hsync, a dot clock signal DCLK and a data enable signal DE A data control signal DDC for controlling the timing and a gate control signal GDC for controlling the operation timing of the gate drive circuit 13 are generated.

The timing controller 11 performs normal driving based on a predetermined reference signal (driving power supply enable signal PEN, vertical synchronizing signal Vsync, data enable signal DE, driving power disable signal PDIS) And the sensing drive can be separated, and the data control signal DDC and the gate control signal GDC can be generated in accordance with each drive. In addition, the timing controller 11 may further generate related switching control signals to operate the internal switches of the respective sensing units SU in accordance with the normal driving and the sensing driving.

The sensing operation may be performed in a predetermined period in which the writing of the input image data (RGB) is stopped. 8, the power-on sequence period X1 immediately after the power of the system necessary for the operation of the organic light emitting display device is applied, or the power-off sequence period X2 immediately after the system power is released, or May be a vertical blank period (VB) arranged between vertical active periods (DF) in which image data (RGB) are written.

The timing controller 11 can check the logical state of the data enable signal DE to judge whether or not the input image data RGB is written. The timing controller 11 monitors the power-on enable signal PEN and the data enable signal DE to know the power-on sequence period X1. The timing controller 11 monitors the power supply disable signal PDIS and the data enable signal DE to know the power off sequence period X2. The timing controller 11 can monitor the vertical blanking period VB by monitoring the vertical synchronization signal Vsync and the data enable signal DE.

The timing controller 11 can transmit digital data corresponding to the sensing data voltage (Vdata_SEN) to the data driving circuit 12 during sensing driving. The timing controller 11 calculates compensation data that can compensate time-varying characteristics of each subpixel SP based on the digital sensing value SD transmitted from the data driving circuit 12 in the sensing operation, May be stored in the memory (16). The timing controller 11 can modulate the input image data RGB for image display with reference to the compensation data stored in the memory 16 during normal driving and then transmit the modulated input image data RGB to the data driving circuit 12. [

The sensing driving of the present invention includes a first sensing driving for sensing a threshold voltage of a driving TFT, a second sensing driving for sensing a mobility of the driving TFT, and a third sensing driving for sensing a threshold voltage of the OLED can do. The degradation sensing method of the present invention to be described below can be applied to all of the first to third sensing drives.

9 and 10 show degradation sensing methods according to an embodiment of the present invention.

9 and 10, a degradation sensing method according to an exemplary embodiment of the present invention includes a step of electrically selecting one subpixel SP from unit pixels UP and electrically connecting to the sensing units SU, , Simultaneously sensing the electrical characteristics of the sub-pixels (SP) connected to the sensing units (SU), while simultaneously sensing the sub-pixels (SP) Color. For example, in each of the horizontal pixel lines L1 to Ln in FIGS. 9 and 10, the subpixels SP simultaneously sensed by one sensing operation include R, W, G, and B subpixels do.

The present invention can minimize the perception of the horizontal pixel line as a bright line during sensing by simultaneously sensing subpixels of all colors simultaneously, rather than sensing only the same color subpixels at the same time. For this purpose, all the subpixels arranged in one horizontal pixel line are sensed once by K (K is the number of subpixels constituting a unit pixel) sensing operation. For example, in FIGS. 9 and 10, all subpixels arranged in one horizontal pixel line can be sensed once by four sensing operations, respectively. In this way, since the subpixels of the specific color (W) most visibly perceived are dispersed and sensed through four sensing operations, it is possible to reduce the perceived contrast.

In addition, the present invention is characterized in that the horizontal color order of the subpixels simultaneously sensed by the first sensing operation and the horizontal color order of the subpixels simultaneously sensed by the second sensing operation are different do. For example, the horizontal color order of the subpixels simultaneously sensed by the first sensing operation of FIGS. 9 and 10 is R, W, G, B, whereas the horizontal color order of the subpixels simultaneously sensed by the second sensing operation is horizontal The direction color order is W, G, B, R. By doing so, the present invention can prevent the W subpixels from being sensed at the same position in consecutive sensing operations, thereby further reducing the perception of horizontal pixel lines as bright lines during sensing.

The present invention may employ a sequential sensing scheme in the vertical direction as shown in FIG. 9, or a random sensing scheme in the vertical direction as shown in FIG.

In the sequential sensing method of FIG. 9, all the horizontal pixel lines L1 to Ln are sequentially sensed from top to bottom, and the subpixels of each horizontal pixel line are also sensed one time by four sequential sensing operations It says. In other words, according to the sequential sensing scheme, all the subpixels of the first horizontal pixel line (for example, L1) are sensed once by the sequential sensing operation four times (sensing # 1 to 4) All the subpixels of the second horizontal pixel line (for example, L2) neighboring the horizontal pixel line are sensed once by the sequential sensing operation four times (sensing # 5 to 8).

The random sensing scheme of FIG. 10 refers to random sensing of all the horizontal pixel lines (L1 to Ln), and random sensing of subpixels of each horizontal pixel line. In other words, according to the random sensing scheme, some of the sub-pixels R, W, G and B of the first horizontal pixel line (for example, L1) are simultaneously sensed by the sensing operation of the first (M is a positive integer equal to or greater than 3) horizontal pixel line L473 in which at least one horizontal pixel line L2 to L472 exists between the first horizontal pixel line L1 and the first horizontal pixel line L1, (W, G, B, R) can be simultaneously sensed by the sensing operation of the second (sensing # 2) following the first (sensing # 1).

With such a random sensing scheme, it is possible to further reduce the perception of the horizontal pixel line as a bright line during sensing by making the time interval in which the W subpixels are sensed at the same position irregular.

FIG. 11 shows an exemplary configuration of a sub-pixel and a sensing unit to which the degradation sensing method of the present invention is applied. FIG. 12 shows a method of sensing an OLED threshold voltage as a single degradation sensing method of the present invention. 11 and 12 are merely examples of the present invention, it should be noted that the technical idea of the present invention is not limited thereto.

11, each subpixel SP includes an OLED, a driving TFT (Thin Film Transistor) DT, a storage capacitor Cst, a first switch TFT ST1, and a second switch TFT ST2 can do.

The OLED includes an anode electrode connected to the source node Ns, a cathode electrode connected to the input terminal of the low potential driving voltage EVSS, and an organic compound layer positioned between the anode electrode and the cathode electrode.

The driving TFT DT controls the current input to the OLED according to the gate-source voltage Vgs. The driving TFT DT has a gate electrode connected to the gate node Ng, a drain electrode connected to the input terminal of the high potential driving voltage EVDD, and a source electrode connected to the source node Ns. The storage capacitor Cst is connected between the gate node Ng and the source node Ns. The first switch TFT ST1 applies the data voltage Vdata (including the data voltage for sensing or the data voltage for black display) on the data line 14A to the gate node Ng in response to the scan control signal SCAN do. The first switch TFT ST1 has a gate electrode connected to the first gate line 15A, a drain electrode connected to the data line 14A, and a source electrode connected to the gate node Ng. The second switch TFT (ST2) switches the current flow between the source node (Ns) and the sensing line (14B) in response to the sensing control signal (SEN). The second switch TFT ST2 has a gate electrode connected to the second gate line 15B, a drain electrode connected to the sensing line 14B, and a source electrode connected to the source node Ns.

Each sensing unit SU may include an initialization switch SW1, a sampling switch SW2, and a sample and hold unit S / H.

The initialization switch SW1 is switched in accordance with the initialization control signal PRE to switch the current flow between the input terminal of the initialization voltage Vpre and the sensing line 14B. The sampling switch SW2 is switched in accordance with the sampling control signal SAM to connect the sensing line 14B and the sample and hold section S / H. The sample-and-hold unit S / H samples and holds the voltage stored in the line capacitor LCa of the sensing line 14B as a sensing voltage when the sampling switch SW2 is turned on, and then transfers it to the ADC. Here, the line capacitor LCa can be replaced with a parasitic capacitor existing in the sensing line 14B.

The OLED threshold voltage sensing method of FIG. 11 will be described based on this connection configuration.

Referring to FIG. 11, the method of detecting deterioration of the present invention is performed through an initialization period (Tint), a degradation tracking interval (Ttrc), a sensing interval (Tsen), and a sampling interval (Tsam).

In the initialization period Tint, the sensing data voltage Vdata_SEN is applied to the gate node Ng of the driving TFT DT and the initialization voltage Vpre is applied to the source node Ns of the driving TFT DT, (DT) is turned on.

In the initialization period Tint, the sensing data voltage Vdata_SEN is applied to the gate node Ng of the driving TFT DT only for the subpixels to be sensed among the unit pixels, and the rest of the unit pixels It is possible to effectively select only the subpixel to be sensed by applying the black display data voltage Vdata_black lower than the sensing data voltage Vdata_SEN to the gate node Ng of each driving TFT DT for the pixels. Unlike the subpixel to which the sensing data voltage Vdata_SEN is applied, the driving TFT DT of the subpixel to which the black display data voltage Vdata_black is applied must not be turned on. To this end, the difference between the black display data voltage (Vdata_black) and the initialization voltage (Vpre) is preferably set to a value lower than the threshold voltage of the driving TFT (DT). In addition, since the initialization voltage Vpre is commonly applied to the subpixels in the unit pixel, it is preferable that the initialization voltage Vpre is set to a value lower than the threshold voltage (operating point voltage) of the OLED so as to prevent unnecessary turn- Do.

In the deterioration tracking period Ttrc, the source node Ns of the driving TFT DT is floated and the drain-source current Ids of the driving TFT DT is applied to the OLED to turn on the OLED. At this time, the source node Ns of the driving TFT DT changes depending on the degree of deterioration of the OLED. The higher the relative deterioration is, the higher the potential of the source node Ns of the driving TFT DT is. Since the potential of the source node Ns indicated by the dotted line in the drawing is higher than the potential of the source node Ns indicated by the solid line, the dotted line shows a state where the deterioration is greater than the solid line. Therefore, the gate-source voltage Vgs of the driving TFT DT is programmed in accordance with the deterioration degree of the OLED in the deterioration tracking period Ttrc. The greater the deterioration of the OLED, the smaller the gate-source voltage Vgs of the driving TFT DT to be programmed. In the figure, Vgs2 when the deterioration is relatively large is smaller than Vgs1 when the deterioration is relatively small.

In the sensing period Tsen, the gate node Ng of the driving TFT DT is floated and the initializing voltage Vpre is applied to the source node Ns of the driving TFT DT to supply the source node Ns of the driving TFT DT Ns) potential with the gate node (Ng) potential. In this case, however, the programmed gate-source voltage Vgs remains unchanged, and the current Ids corresponding to the programmed gate-source voltage Vgs flows in the drive TFT DT, Is charged with the current Ids. Since the magnitude of the current Ids is proportional to the programmed gate-source voltage Vgs, the greater the deterioration, the lower the rate at which the line capacitor of the sensing line 14B is charged (represented by the slope in the figure).

In the sampling period Tsam, the voltage stored in the line capacitor LCa is output as the sensing voltage Vsen.

As described above, the present invention can minimize the perception of the horizontal pixel line as a bright line during sensing by simultaneously sensing subpixels of all colors simultaneously, rather than sensing only subpixels of the same color at the same time in one sensing have.

In addition, the present invention is characterized in that the horizontal color order of the subpixels simultaneously sensed by the first sensing operation and the horizontal color order of the subpixels simultaneously sensed by the second sensing operation are different It is possible to prevent a specific sub-pixel having a large amount of light emission from being sensed at the same position in a continuous sensing operation, thereby further reducing the perception of the horizontal pixel line during the sensing as a bright line.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

10: Display panel 11: Timing controller
12: data driving circuit 13: gate driving circuit
14A: Data line 14B: Sensing line
15: gate line

Claims (8)

A method for sensing deterioration of an organic light emitting display device including a plurality of unit pixels each including subpixels of different colors and a plurality of sensing units for sensing electrical characteristics of the subpixels,
Selecting one subpixel from the unit pixels and electrically connecting the subpixels to the sensing units; And
Sensing simultaneously the electrical characteristics of the subpixels connected to the sensing units,
Wherein the subpixels sensed at the same time have different colors between horizontally adjacent unit pixels. The method according to claim 1,
Wherein all the subpixels arranged in one horizontal pixel line are sensed once by a sensing operation of K (K is a number of subpixels constituting a unit pixel) sensing operation. The method according to claim 1,
The horizontal color sequence of the subpixels simultaneously sensed by the first sensing operation may be different from the horizontal color sequence of the subpixels simultaneously sensed by the second sensing operation subsequent to the first sensing operation, Sensing method. The method according to claim 2 or 3,
All the subpixels of the first horizontal pixel line are each sensed once by the K sequential sensing operations,
And each subpixel of a second horizontal pixel line adjacent to the first horizontal pixel line is sensed once by K sequential sensing operations. The method according to claim 2 or 3,
Some sub-pixels of the first horizontal pixel line are simultaneously sensed by the first sensing operation,
Some of the subpixels of the Mth (M is a positive integer equal to or greater than 3) horizontal pixel line in which at least one horizontal pixel line exists between the first horizontal pixel line and the first horizontal pixel line Wherein the sensing of the deterioration of the organic light emitting display device is performed simultaneously. The method according to claim 2 or 3,
Wherein the sensing operation is performed for a predetermined period during which no image data is written to the subpixels. The method according to claim 6,
Wherein,
A power-off sequence period immediately after the system power required for the operation of the organic light emitting display device is applied, or a power-off sequence period immediately after the system power is released, or between vertical active periods in which the image data is written And a vertical blank period. The method according to claim 1,
The electrical characteristics of the sub-
Pixels, at least one of a threshold voltage of an OLED included in the sub-pixels, a threshold voltage of a driving TFT provided in the sub-pixels, and a mobility of a driving TFT provided in the sub-pixels. Deterioration sensing method.

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