KR102429322B1 - Organic light emitting display apparatus - Google Patents

Abstract

It is an object of the present invention to provide an organic light emitting display device that cuts off power supplied to a panel on which an image is output when it is determined that an abnormal condition occurs after image output is cut off according to a power-off control signal. To this end, the organic light emitting display device according to the present invention includes a panel including pixels, each of which includes an organic light emitting diode and a pixel driving circuit for driving the organic light emitting diode, and data lines provided in the panel. and a data driver for supplying data voltages, a gate driver for sequentially supplying gate pulses to gate lines provided in the panel, and a controller for controlling the data driver and the gate driver. Here, when a power-off control signal for blocking an image output from the panel is detected, the controller stops the functions of outputting the image. In addition, if it is determined that an abnormal condition has occurred after the image output is cut off, the controller cuts off the power supplied to the panel.

Description

Organic light emitting display device {ORGANIC LIGHT EMITTING DISPLAY APPARATUS}

The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device that performs a sensing operation for threshold voltage compensation according to a power-off control signal.

A Flat Panel Display Apparatus is used in various types of electronic products including mobile phones, tablet PCs, and notebook computers. A flat panel display device (hereinafter, simply referred to as a 'display device') includes a liquid crystal display device (LCD), an organic light emitting display device (OLED), and the like.

In a conventional organic light emitting diode display, a characteristic deviation such as a threshold voltage Vth of a driving transistor occurs for each pixel due to process deviation, deterioration, or the like. Accordingly, the amount of current that drives each organic light emitting diode is different, which causes a luminance deviation between pixels.

In order to solve the above problem, after the power-off control signal is detected, a sensing operation for threshold voltage compensation is performed. The sensing operation is performed immediately or after a predetermined time has elapsed after the output of the image is blocked by the power-off control signal, and is referred to as a Real Time Slow Mode. Therefore, hereinafter, the sensing operation for compensating the threshold voltage is simply referred to as OFF-RS.

1 is a flowchart illustrating a conventional OFF-RS method.

In the organic light emitting display device, various protection functions are performed to prevent damage to the panel due to the occurrence of an abnormal condition.

For example, in the organic light emitting display device, a function of detecting whether a gate high voltage VGH and a gate low voltage VGL used to generate a gate pulse abnormally change, and a driving function provided in an organic light emitting display panel The function of detecting whether the threshold voltage or mobility of the transistor is abnormally changed and whether the lock signal is normally transmitted and received when communication is performed by the Embedded Clock Point-Point Interface (EPI) protocol functions to detect

Also, after the power-off control signal is detected, the organic light emitting display device performs OFF-RS as shown in FIG. 1 . Accordingly, the organic light emitting display device implements the above-described protection functions and the OFF-RS.

The protection function and the OFF-RS will be briefly described as follows.

When the organic light emitting display device is turned on, the organic light emitting display device outputs an image (S102).

An abnormal condition may occur while an image is being output (S104). For example, an abnormal high voltage may be generated or a short circuit may occur.

In this case, the organic light emitting diode display may detect the abnormal condition by operating the protection functions ( S106 ).

When the abnormal condition occurs, an image is not output from the organic light emitting display device (S108). Even if an image is not output from the organic light emitting display device, the control unit for driving the organic light emitting display device continuously operates.

In this case, the control unit determines whether a condition for performing the OFF-RS occurs (S110). For example, the controller determines a period from when the organic light emitting diode display device is turned on and starts an operation until the output of the image is stopped. If the period exceeds a preset period, for example, 2 hours, the control unit performs OFF-RS, and if it does not exceed 2 hours, the control unit does not perform OFF-RS.

As a result of the determination, when a condition for performing OFF-RS occurs, the control unit performs OFF-RS (S112). For example, the controller drives the organic light emitting display panel to sense the amount of change in threshold voltages of driving transistors included in the organic light emitting display panel. The controller sets a compensation value according to the sensed threshold voltage and stores the compensation value. The compensation value may be used when the organic light emitting display device is turned on and an image is output ( S102 ).

As a result of the determination, if the condition for performing the OFF-RS does not occur, the power of the organic light emitting diode display is turned off (S114).

As described above, in the conventional organic light emitting display device, even if an abnormal condition is detected (S106) and the image output is blocked (S108), the OFF-RS may be performed depending on whether the OFF-RS condition occurs. have.

After an abnormal condition is detected (S106) and the image output is cut off (S108), when an OFF-RS condition is generated and OFF-RS is performed, a sensing voltage and current flow to the organic light emitting display panel.

In this case, since an abnormal condition has already occurred in the organic light emitting display panel, when the sensing voltage and current flow, an excessive load may be applied to the organic light emitting display panel.

Accordingly, a defect in which a polarizing film provided in the organic light emitting display panel is melted may occur, and damage to the organic light emitting display panel may be increased.

That is, conventionally, even if an abnormal condition is detected (S106) and the image output is blocked (S108), OFF-RS may be performed. In this case, an abnormal current may continuously flow through the organic light emitting display panel, and accordingly, the organic light emitting display panel may be damaged.

An object of the present invention, which has been proposed to solve the above problem, is to cut off the power supplied to the panel on which the image is output when it is determined that an abnormal condition occurs after the image output is cut off according to a power-off control signal. To provide a light emitting display device.

According to an aspect of the present invention, there is provided an organic light emitting display device comprising: a panel including an organic light emitting diode and a pixel driving circuit for driving the organic light emitting diode in each of the pixels; and a data driver supplying data voltages to data lines provided in the panel, a gate driver sequentially supplying gate pulses to gate lines provided in the panel, and a controller controlling the data driver and the gate driver. In particular, when a power-off control signal for blocking the image output from the panel is detected, the control unit stops the functions of outputting the image. In addition, when it is determined that an abnormal condition occurs after the image output is cut off, the controller cuts off the power supplied to the panel.

The present invention performs an operation of determining whether a sensed threshold voltage is out of a preset range while performing a sensing operation for threshold voltage compensation after image output is cut off according to a power-off control signal, As a result of the determination, if it is determined that the sensed threshold voltage is out of a preset range, the sensing operation is stopped.

Accordingly, according to the present invention, when an abnormal condition occurs in the panel, the sensing operation that may damage the panel is stopped, thereby preventing damage to the panel.

1 is a flowchart illustrating a conventional OFF-RS method.
2 is an exemplary view showing the configuration of an organic light emitting display device according to the present invention.
3 is an exemplary view showing the configuration of a pixel applied to an organic light emitting display device according to the present invention.
4 is an exemplary view showing the configuration of a control unit applied to an organic light emitting display device according to the present invention.
5 is an exemplary diagram illustrating a configuration of a data driver applied to an organic light emitting display device according to the present invention.
6 is a flowchart illustrating a method of driving an organic light emitting display device according to an exemplary embodiment;

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and those of ordinary skill in the art to which the present invention pertains. It is provided to fully inform the person of the scope of the invention, and the present invention is only defined by the scope of the claims.

It should be noted that in the present specification, in adding reference numbers to the components of each drawing, the same numbers are used for the same components, even if they are indicated on different drawings, as much as possible.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative and the present invention is not limited to the illustrated matters. Like reference numerals refer to like elements throughout. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless specifically stated otherwise.

In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between two parts unless 'directly' is used.

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal relationship is described as 'after', 'following', 'after', 'before', etc. It may include cases that are not continuous unless this is used.

The term 'at least one' should be understood to include all possible combinations of one or more related items. For example, the meaning of 'at least one of the first item, the second item and the third item' is not only the first item, the second item, or the third item respectively, but also 2 of the first item, the second item and the third item. It means a combination of all items that can be presented from more than one.

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

Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each embodiment may be independently implemented with respect to each other or implemented together in a related relationship. may be

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is an exemplary view showing the configuration of an organic light emitting display device according to the present invention, FIG. 3 is an exemplary view showing the configuration of a pixel applied to the organic light emitting display device according to the present invention, and FIG. 4 is an organic light emitting diode display according to the present invention. It is an exemplary diagram showing a configuration of a control unit applied to a light emitting display device, and FIG. 5 is an exemplary diagram showing a configuration of a data driver applied to an organic light emitting display device according to the present invention.

As shown in FIGS. 2 to 5 , the organic light emitting display device according to the present invention includes pixels (P) 110 , and each of the pixels includes an organic light emitting diode (OLED) and the organic light emitting diode. A panel 100 including a pixel driving circuit (PDC) for driving, a data driver 300 supplying data voltages to data lines DL1 to DLd provided in the panel 100, and the panel 100 a gate driver 200 sequentially supplying a gate pulse GP to the gate lines GL1 to GLg provided in the and a power supply unit 500 for supplying power to the gate driver 200 , the data driver 300 , and the control unit 400 . In particular, when a power-off control signal for blocking the image output from the panel 100 is detected, the controller 400 blocks the image data transmitted to the panel 100 . In addition, if it is determined that an abnormal condition has occurred after the image output is cut off, the controller 100 cuts off the power supplied to the panel 100 .

First, as shown in FIG. 3 , in the panel 100 , the organic light emitting diode (OLED), a driving transistor (Tdr) for controlling the current flowing through the organic light emitting diode (OLED), and the data line (DL) ) and a pixel driving circuit PDC including a switching transistor Tsw1 connected between the driving transistor Tdr and the gate line GL. In addition, signal lines that define a pixel region in which the pixels 110 are formed and supply a driving signal to the pixel driving circuit PDC are formed on the panel 100 .

In addition, a sensing transistor Tsw2 for external compensation is provided in the pixel driving circuit PDC provided in each of the pixels 110 .

First, the signal lines are the gate line GL, the sensing pulse line SPL, the data line DL, the sensing line SL, a first driving power line PLA, and a second driving power line PLB. includes

Next, the gate lines GL are formed in parallel to have a constant interval along the second direction of the panel 100 , for example, a horizontal direction.

Next, the sensing pulse lines SPL may be formed at regular intervals to be parallel to the gate lines GL. In addition, the gate line GL and the sensing pulse line SPL formed on one horizontal line may be common to form one line.

Next, the data line DL has a predetermined interval along the first direction, for example, a vertical direction, of the panel 100 to intersect each of the gate line GL and the sensing pulse line SPL. can be formed side by side. However, the arrangement structure of the data line DL and the gate line GL may be variously changed.

Next, the sensing line SL may be formed at regular intervals to be parallel to the data lines DL. However, it is not necessarily limited thereto.

At least three of the pixels 110 form one unit pixel 120 . In the following description, the present invention will be described by taking as an example a case in which four pixels 110 (a red pixel, a white pixel, a green pixel, and a blue pixel) form one unit pixel. In this case, one sensing line SL may be formed in the unit pixel. Accordingly, when d data lines DL1 to DLd are formed on a horizontal line of the panel 100 , the number k of the sensing lines SL may be d/4.

In more detail, the data lines are formed in the first direction (vertical direction) of the panel 100 , the sensing lines SL are formed in parallel with the data lines, and the sensing lines ( Each of the SLs may be connected to four pixels 110 constituting each of the unit pixels formed on one horizontal line.

Next, the first driving power line PLA may be formed at regular intervals to be parallel to the data line DL. Here, the first driving power line PLA may be formed at regular intervals to be parallel to the sensing line SL. The first driving power line PLA is connected to the power supply unit 500 to supply the first driving power EVDD supplied from the power supply unit 500 to each pixel 110 .

Next, the second driving power lines PLB may be formed at regular intervals to be parallel to each of the data lines DL1 to DLd or the gate lines GL1 to SLk. The second driving power line PLB supplies the second driving power EVSS supplied from the power supply unit 500 to each pixel 110 . For example, the second driving power lines PLB may be electrically grounded to a metal case (or cover) constituting the organic light emitting display device. In this case, the second driving power lines are connected to each pixel ( 110) to provide a grounding power (ground).

Next, each of the plurality of pixels 110 is formed for each pixel area defined by each of the gate lines GL1 to GLg and the data lines DL1 to DLd. Here, each of the plurality of pixels P may be any one of a red pixel, a green pixel, a blue pixel, and a white pixel.

As shown in FIG. 3 , each of the plurality of pixels 110 may include the pixel driving circuit (PDC) and an organic light emitting diode (OLED).

Finally, the pixel driving circuit PDC includes the switching transistor Tsw1, the sensing transistor Tsw2, the 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 switching transistor Tsw1 is switched by the gate pulse GP to output the data voltage Vdata supplied to the data line DL. To this end, the switching transistor Tsw1 has a gate connected to the adjacent gate line GL, a first electrode connected to the adjacent data line DL, and a first node connected to a first node n1 that is the gate of the driving transistor Tdr. Includes 2 electrodes.

The sensing transistor Tsw2 is switched by the sensing pulse SP and supplies the reference voltage Vref supplied to the sensing line SL to the second node n2 that is the source electrode of the driving transistor Tdr. do. To this end, the sensing transistor Tsw2 includes a gate connected to the adjacent sensing pulse line SPL, a first electrode connected to the adjacent sensing line SL, and a second electrode connected to the second node n2 .

The capacitor Cst is charged with a difference voltage between the voltages supplied to each of the first and second nodes n1 and n2 according to the switching of the switching transistor Tsw1 and the sensing transistor Tsw2, respectively. The driving transistor Tdr is switched according to the voltage.

The driving transistor Tdr is turned on by the voltage of the capacitor Cst to control the amount of current flowing from the first driving power line PLA to the organic light emitting diode OLED. To this end, the driving transistor Tdr includes a gate connected to the first node n1, a first electrode connected to the second node n2, and a second electrode connected to the first driving power line PLA. do.

The organic light emitting diode OLED emits light with a luminance corresponding to the data current by emitting light by the data current supplied from the driving transistor Tdr. To this end, the organic light emitting diode OLED includes a first electrode (eg, an anode electrode) connected to the second node n2 , that is, the first electrode of the driving transistor Tdr, and the first electrode and an organic layer formed thereon and a second electrode (eg, a cathode electrode) connected to the organic layer. The second electrode of the organic light emitting diode (OLED) may be the second driving power line PLB formed on the organic layer, or may be additionally formed on the organic layer to be connected to the second driving power line PLB. can

In the above description, the structure of the pixel 110 for performing the external compensation has been described with reference to FIG. 3 , but the structure of the pixel 110 for performing the external compensation may be different from the structure shown in FIG. 3 . structure can be formed.

For example, the external compensation is the amount of change in the threshold voltage or mobility of the driving transistor Tdr formed in the pixel 110 , and the amount of data voltages supplied to the unit pixel according to the change amount is calculated. means to change Accordingly, the structure of the pixel 110 may be changed in various forms so that a change amount of the threshold voltage or mobility of the driving transistor Tdr can be calculated.

In addition, for external compensation, a method of calculating a threshold voltage or mobility change amount of the driving transistor Tdr using the pixel 110 may be variously changed according to the structure of the pixel 110 . .

In more detail, the present invention relates to an organic light emitting display device that cuts off power supplied to a panel on which an image is output when it is determined that an abnormal condition occurs after image output is cut off according to a power-off control signal. Although the present invention is applied to an organic light emitting diode display configured to perform external compensation, the structure and method for performing external compensation are not directly related to the present invention. Accordingly, a pixel structure for external compensation and a method for performing external compensation may include various pixel structures and various external compensation methods currently being proposed for external compensation. For example, the structure and method of the pixel 110 for external compensation and the method of performing external compensation are applied to the structures and methods disclosed in a number of publications including Korean Patent Application Laid-Open No. 10-2013-0066449. In addition, the inventions disclosed in Application No. 10-2013-0150057 and Application No. 10-2013-0149213 filed by the present applicant may also be applied.

That is, a specific structure of a pixel for performing external compensation and a specific method of external compensation are outside the scope of the present invention. Accordingly, an example of a pixel for external compensation has been briefly described with reference to FIG. 3 , and an external compensation method is also briefly described below.

Second, the gate driver 200 sequentially supplies a gate pulse GP to the gate lines GL1 to GLg using the gate control signals GCS transmitted from the controller 400 .

Here, the gate pulse GP refers to a signal capable of turning on the switching transistor Tsw1 connected to the gate lines GL1 to GLg. A signal capable of turning off the switching transistor Tsw1 is referred to as a gate-off signal. The gate pulse GP and the gate-off signal are collectively referred to as a gate signal.

The gate driver 200 is formed independently of the panel 100 and may be connected to the panel 100 through a tape carrier package (TCP) or a flexible printed circuit board (FPCB), but a gate-in panel ( It may be directly mounted in the panel 100 using a Gate In Panel: GIP method.

Third, the power supply unit 500 supplies power to the gate driver 200 , the data driver 300 , and the control unit 400 .

Fourth, as shown in FIG. 4 , the control unit 400 uses a timing synchronization signal TSS input from the external system 900 to control the driving of the gate driver 200 . (GCS) and a data control signal DCS for controlling driving of the data driver 300 are respectively generated.

Also, in the sensing mode in which sensing for external compensation is performed, the controller 400 transmits the sensing image data to be supplied to the pixels formed on the horizontal line on which external compensation is performed to the data driver 300 . Sensing for the external compensation may be performed at various timings, for example, the external compensation may be performed during a blanking period.

The blanking period is inserted between image output periods in which images are output. That is, the blanking period means a period during which an image is not output during one frame period, and the image output period means a period during which an image is output during the one frame period. When a power-on control signal is received from the external system 300 , the organic light emitting diode display is driven, and accordingly, the one frame period is repeated to output an image.

When the power-off control signal transmitted from the external system 300 is detected, the organic light emitting display device stops functions for outputting an image. Accordingly, no image is output from the panel 100 .

However, even if the output of the image is cut off and the image is not displayed to the user, power is supplied to the organic light emitting display device for, for example, 2 to 10 minutes. The organic light emitting display device performs a sensing operation for compensating the threshold voltage of the driving transistors Tdr for 2 to 10 minutes after the output of the image is cut off. The sensing operation is performed for 2 to 10 minutes immediately after the output of the image is blocked by the power-off control signal or after a predetermined time has elapsed, and is referred to as a Real Time Slow Mode. The sensing operation for compensating the threshold voltage is referred to as OFF-RS.

The control unit 400 calculates an external compensation value based on the sensing data Sdata provided from the data driver 300 in the sensing mode, and stores the external compensation value in 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 compensates the input image data (Ri, Gi, Bi) transmitted from the external system 900 during the image display period in which the image is output using the external compensation value to convert it into external compensation image data, or Alternatively, the input image data is rearranged without external compensation, and converted into general image data and output. The data driver 300 converts the externally compensated image data or the general image data into a data voltage Vdata, and then supplies the data voltage Vdata to the data line.

In order to perform the above-described function, the controller 400, as shown in FIG. 4, uses the timing synchronization signal TSS transmitted from the external system 900 to A data alignment unit 430 for rearranging input image data Ri, Gi, and Bi and supplying the rearranged image data to the data driver 300, the gate control signal ( GCS), a control signal generator 420 for generating the data control signal DCS and the power control signal PCS, and the pixel (Sdata) using the sensing data Sdata transmitted from the data driver 300. A determination unit 410 for calculating an external compensation value for compensating for a characteristic change of the driving transistor Tdr formed in each of 110), a storage unit 450 for storing the external compensation value, and the data arrangement An output unit 440 for outputting the image data and control signals DCS, PCS, and GCS generated by the unit 430 to the data driver 300 , the gate driver 200 , or the power supply unit 500 . includes

Fifth, the data driver 300 is connected to the data lines DL1 to DLd and the sensing lines SL1 to SLk, and according to a control signal transmitted from the control unit 400 , a sensing mode or a display mode works with The sensing mode and the display mode are executed during a period in which an image is output through the panel 100 according to the power-on control signal.

As shown in FIG. 5 , the data driver 300 includes a data voltage output unit 310 and a sensing unit 320 .

The data voltage output unit 310 is connected to the data lines DL, and the sensing unit 320 is connected to the sensing lines SL.

In the sensing mode, the sensing unit 320 supplies a reference voltage Vref to each of the sensing lines SL1 to SLk, and then receives a signal corresponding to the reference voltage Vref, A change in characteristics of the driving transistor Tdr included in the pixels P formed on the horizontal line is sensed using the signal to generate sensing data Sdata. The sensing unit 320 provides the generated sensing data Sdata to the control unit 400 . The control unit 400 calculates the external compensation value using the sensing data Sdata.

The data voltage output unit 310 converts the image data transmitted from the controller 400, ie, the external compensation image data or the general image data, into a data voltage in the sensing mode to convert the data A voltage is supplied to the data line. In the display mode, the data voltage output unit 310 transmits the image data Data supplied from the control unit 400 in units of horizontal lines by using a plurality of reference gamma voltages supplied from the reference gamma voltage supply unit. It is converted into voltage and supplied to the corresponding data line DL.

In more detail, the data voltage output unit 310 samples the image data Data of each pixel 110 input in units of one horizontal line according to the data control signal DCS, and the plurality of standards Among the gamma voltages, gamma voltages corresponding to the grayscale values of the sampling data are selected as the data voltages and supplied to the data lines DL.

In the sensing mode, the sensing unit 320 senses each sensing voltage received from the sensing lines SL1 to SLk, and generates sensing data Sdata corresponding to the sensing voltage to generate the sensing voltage Sdata, and the control unit 400 ) is provided for To this end, the sensing unit 320 may include an analog-to-digital converter that digitally converts the sensing voltage transmitted from the sensing lines SL1 to SLk to generate the sensing data Sdata. The sensing unit 320 may perform the sensing during the blanking period.

6 is a flowchart illustrating a method of driving an organic light emitting display device according to an exemplary embodiment.

As described above, the organic light emitting display device according to the present invention includes the panel 100 , the data driver 300 , the gate driver 300 , the control unit 400 , and the power supply unit 500 . include

The external system 900 is a system for driving an electronic product to which the organic light emitting display device according to the present invention is applied.

For example, when the electronic product is a television, the external system 900 receives audio information and image information through a communication network, and receives the input image data Ri, Gi, and Bi constituting the image information. It is transmitted to the control unit 400 .

When the electronic product is a smartphone, the external system 900 receives audio information or image information through a communication network, generates various audio files and image files, and inputs the image information and the image files. The image data Ri, Gi, and Bi are transmitted to the control unit 400 .

When a power-off control signal for blocking the image output from the panel 100 is detected, the control unit 400 stops the functions of outputting the image.

For example, the controller 400 may not transmit image data to the data driver 300 or may prevent the gate driver 400 from outputting the gate pulse.

After the image output is cut off, the control unit 400 performs a sensing operation OFF-RS for compensating the threshold voltage of the driving transistor Tdr provided in the pixel driving circuit PDC. When it is determined that the sensed threshold voltage is out of a preset range while performing the sensing operation (OFF-RS) for threshold voltage compensation, the control unit 400 stops the threshold voltage compensation. For example, when an abnormal condition is detected while performing the sensing operation OFF-RS after the image output is cut off, the controller 400 cuts off the power supplied to the panel 100 .

Accordingly, overcurrent or overvoltage may not be supplied to the panel 100 due to the abnormal condition, and thus, damage to the panel 100 may be prevented.

In order to perform the above function, the control unit 400 includes the data alignment unit 430 , the control signal generation unit 420 , the determination unit 430 , and the output unit 440 . .

As described above, the data aligning unit 430 rearranges the input image data (Ri, Gi, Bi) transmitted from the external system 900 and outputs the rearranged image data (Data) to the data driver 300 . ) is supplied.

The control signal generator 420 generates a gate control signal GCS for controlling the gate driver 200 and a data control signal DCS for controlling the data driver 300 .

The determination unit 410 determines whether the abnormal condition has occurred using the sensing data Sdata transmitted from the data driver 300 . The sensing data Sdata is generated by the data driver 300 , in particular, the sensing unit 320 .

As described above, while an image is output according to the turn-on control signal, the sensing unit 320 senses a threshold voltage or mobility, and transmits the sensing data (Sdata) generated by the sensing result to the control unit. send to

In addition, the sensing unit 320 performs a sensing operation (OFF) for compensating a threshold voltage of the driving transistor Tdr provided in the pixel driving circuit PDC even while an image is not output according to the turn-off control signal. -RS). The sensing unit 320 transmits the sensing data Sdata generated by the sensing operation OFF-RS for the threshold voltage compensation to the determining unit 410 .

In more detail, the sensing data Sdata may be a signal transmitted from the sensing unit 320 while an image is being output, or may be a signal transmitted from the sensing unit 320 while an image is not being output. However, hereinafter, since the sensing operation OFF-RS for compensating the threshold voltage will be described while no image is output, the sensing data Sdata is transmitted from the sensing unit 320 while no image is output. is a signal to be The sensing data Sdata includes information related to a threshold voltage of the driving transistor Tdr.

When it is determined that the abnormal condition has occurred, the determination unit 410 cuts off the power supplied to the panel 100 .

The determination unit 410 includes the first driving power lines PLA and the second driving power lines PLB, the gate driver 200 and the data driver 300 provided in the panel 100 . The power control signal PCS may be transmitted to the power supply unit 500 for supplying power. When the power control signal PCS is received, the power supply unit 500 cuts off power supplied to the driving power lines PLA and PLB, the gate driver 200 and the data driver 300 .

In more detail, if the controller 400 determines that an abnormal condition has occurred after the image output is cut off, the driving power lines PLA and PLB provided in the panel 100 and the gate driver 200 ) and transmits the power control signal PCS to the power supply unit 500 that supplies power to the data driver 300 , and the power supply unit 500 receives the power control signal PCS, the Power supplied to the driving power lines PLA and PLB, the gate driver 200 and the data driver 300 may be cut off.

The driving power lines may include various lines for supplying power to various devices included in the panel in addition to the first driving power lines PLA and the second driving power lines PLBs.

Hereinafter, a method of driving an organic light emitting display device according to the present invention will be described with reference to FIGS. 2 to 6 . In the following description, the same or similar contents to those described above are omitted or simply described.

First, when the power-on control signal is received from the external system 900 , the organic light emitting diode display starts driving. Accordingly, an image is output from the panel 100 (S602).

Next, an abnormal condition is generated in the organic light emitting display panel 100 due to various causes ( S604 ).

For example, an abnormal high voltage or a short circuit may be generated in the panel 100 , and accordingly, the magnitudes of the gate high voltage VGH and the gate low voltage VGL used to generate the gate pulse are decreased. It can be changed to an abnormal level.

Also, the threshold voltage or mobility of the driving transistor Tdr may be changed to an abnormal level.

In addition, when the organic light emitting display device performs communication according to an Embedded Clock Point-Point Interface (EPI) protocol, a lock signal may not be normally generated and received.

Next, the organic light emitting display device detects the above-described abnormal condition by performing various protection functions as described above (S606).

For example, the organic light emitting diode display may detect abnormal changes in a gate high voltage VGH and a gate low voltage VGL used to generate the gate pulse.

Also, the organic light emitting display device may detect an abnormal change in the threshold voltage or mobility of the driving transistor Tdr provided in the panel 100 .

Also, the organic light emitting display device may detect that the lock signal is not normally transmitted and received when communication is performed according to the Embedded Clock Point-Point Interface (EPI) protocol.

Next, when the abnormal condition as described above is detected, the control unit 400 stops the function of outputting an image. Accordingly, an image is not output from the panel 100 (S608).

In this case, a power-off control signal may be transmitted to the control unit 400 from the components detecting the abnormal condition, and the control unit 400 may detect the power-off control signal.

For example, the gate driver 200 that has confirmed that the gate high voltage VGH or the gate low voltage VGH is abnormal may transmit the power-off control signal to the controller 400 .

Also, the data driver 300 confirming that the lock signal is abnormal may transmit the power-off control signal to the controller 400 .

In addition, the data driver 300 confirming that the threshold voltage or the mobility is abnormal may transmit the power-off control signal to the controller 400 .

Accordingly, the control unit 400 may detect the power-off control signal transmitted from the gate driver 200 or the data driver 300 .

In addition, the control unit 400 includes information from the gate driver 200 or the data driver 300 that can confirm that the gate high voltage VGH or the gate low voltage VGH is abnormal; Information for confirming that the lock signal is abnormal, information for confirming that the threshold voltage or the mobility is abnormal, and analyzing the information, the gate high voltage (VGH) or the gate low voltage ( VGH), etc., may be confirmed that the lock signal is abnormal, or that the threshold voltage or the mobility is abnormal. In this case, the control unit 400 may generate the power-off control signal by itself, and accordingly, the control unit 400 may detect the power-off control signal.

In more detail, the power-off control signal may be detected after being generated by the controller 400 itself, or may be received from external components.

Accordingly, the control unit 400 may detect the power-off control signal generated by the detection of the abnormal condition, and when the power-off control signal is received, the control unit 400 stops the function of outputting an image. do.

Also, the control unit 400 may detect the power-off control signal transmitted from the external system 900 .

For example, the user may turn off the power switch of an electronic product to which the present invention is applied, for example, a TV, a tablet PC, a notebook computer, and a smart phone.

In this case, the external system 900 may transmit the power-off control signal to the controller 400 .

When the power-off control signal transmitted from the external system 900 is detected, the control unit 400 stops the function of outputting an image.

In more detail, the power-off control signal may be detected when the abnormal condition occurs, or may be detected when the user voluntarily turns off the power switch of the electronic product to which the present invention is applied. . When the power-off control signal is detected, the control unit 400 stops the function of outputting an image.

Next, even after the output of the image is stopped, for a certain period of time, for example, 2 to 10 minutes, the power supply unit 500 , the control unit 400 , the gate driver 200 and the data driver 400 Power is supplied.

In this case, the controller 400 determines whether a condition for performing a sensing operation OFF-RS for compensating a threshold voltage of the driving transistor Tdr provided in the pixel driving circuit PDC is generated. (S610).

For example, the controller determines a period from when the organic light emitting diode display device is turned on and starts an operation until the output of the image is stopped.

If the period exceeds a preset period, for example, 2 hours, the control unit performs the sensing operation (OFF-RS), and if it does not exceed 2 hours, the control unit does not perform the OFF-RS .

Next, if the condition for performing the sensing operation OFF-RS does not occur as a result of the determination ( S610 ), the power of the organic light emitting diode display is turned off ( S612 ). In this case, the power supplied from the external system 900 to the power supply unit 400 may be cut off.

However, the power supplied from the external system 900 may not be completely cut off. For example, when the presence or absence of a touch of the organic light emitting display device is to be determined while the organic light emitting display device does not output an image, the minimum power required for determining the touch presence is transmitted to the organic light emitting display device. can

Next, as a result of the determination (S610), when a condition for performing the sensing operation (OFF-RS) is generated, the control unit 400 performs the sensing operation (OFF-RS) (S614, S616, S618).

In this case, the controller 400 drives the panel 100 to sense a change amount of the threshold voltage of the driving transistors Tdr provided in the panel 100 .

For example, the control unit 400 generates image data required for sensing the amount of change in the threshold voltage and transmits it to the data driver 300, and the data driver 300, as shown in FIG. A sensing data voltage Vsen is supplied to the data line DL using the image data.

When one sensing line SL is commonly connected to a unit pixel composed of four pixels, the sensing data voltage Vsen may be supplied only to data lines corresponding to a pixel of a color for which a threshold voltage is to be measured. have.

Also, the controller 400 supplies the gate pulse GP to the gate line GL provided in the horizontal line for measuring the threshold voltage among the gate lines GL1 to GLg. Accordingly, the switching transistor Tsw1 provided in the pixel for which the threshold voltage is measured is turned on.

Also, under the control of the controller 400 , the sensing pulse SP is supplied to the sensing pulse line SPL. Accordingly, the sensing transistor Tsw2 provided in the pixel for which the threshold voltage is measured is turned on.

In this case, since the switching transistor Tsw1 is turned on, the sensing data voltage Vsen supplied to the data line DL is applied to the first node n1 and the second node n2. , may also be applied to the sensing transistor Tsw2.

A voltage difference between the first node n1 and the second node n2 is a voltage difference between the gate and the source of the driving transistor Tdr.

In this case, the sensing unit 320 converts the voltage or current received through the sensing transistor Tsw2 into a digital signal. The sensing data Sdata converted into a digital signal is transmitted to the controller 400 .

The sensing data Sdata is transmitted to the controller 400 through various methods other than the method described above. That is, the sensing data Sdata used when analyzing the threshold voltage of the driving transistor or the amount of change in the threshold voltage of the driving transistor is generated by the sensing unit 320 through various methods currently used, and then the control unit (400).

The controller 400 may analyze the sensing data Sdata to analyze the threshold voltage of the driving transistor Tdr or the amount of change in the threshold voltage of the driving transistor Tdr.

The control unit 400 extracts an external compensation value by using the threshold voltage or a change amount of the threshold voltage, and stores the external compensation value in the storage unit 450 . In addition, the control unit 400 stores the threshold voltage or a change amount of the threshold voltage in the storage unit 450 . The external compensation value stored in the storage unit 400 may be used when the organic light emitting display device is turned on again and an image is output from the panel 100 . That is, the controller 400 may generate the image data Data by correcting the input image data Ri, Gi, and Bi using the external compensation value.

The sensing data Sdata is sequentially generated for each horizontal line while the gate pulse GP is sequentially supplied to the gate lines GL1 to GLg. In this case, when the sensing line SL is commonly connected to one unit pixel composed of four pixels R, G, B, and W, a gate pulse is sequentially applied to the gate lines GL1 to GLg. While being supplied, sensing data of pixels corresponding to any one color among pixels included in the panel is generated.

Accordingly, when the gate pulses are sequentially supplied to all of the gate lines GL1 to GLg, threshold voltages or changes in threshold voltages of the driving transistors Tdr provided in pixels expressing one color are measured. .

Accordingly, when the unit pixel is composed of a red pixel, a green pixel, a blue pixel, and a white pixel, a gate pulse must be supplied to one gate line four times to generate sensing data of all pixels included in the panel. .

Next, while performing the sensing operation (OFF-RS), the control unit 400 determines whether the threshold voltage or a change amount of the threshold voltage is within a preset range (S614). That is, the control unit 400 determines whether an abnormal condition is detected while performing the sensing operation (OFF-RS) (S614).

For example, when a short circuit occurs in the panel 100 , an overcurrent flows, or an overvoltage is supplied, the threshold voltage or the amount of change in the threshold voltage is out of a preset range.

Accordingly, when the control unit 400 performs the sensing operation (OFF-RS), when the threshold voltage or the amount of change in the threshold voltage is out of the range of the preset threshold voltage or the amount of change in the preset threshold voltage, the It may be determined that an abnormal condition has occurred in the panel 100 .

Next, as a result of the determination ( S614 ), if an abnormal condition does not occur, the control unit 400 continuously performs the sensing operation (OFF-RS) ( S618 ).

Accordingly, while the sensing operation OFF-RS is performed, the gate lines GL1 to GLg, the data lines DL1 to DLd, the sensing lines SL1 to SLk, and the first driving power supply Various voltages or currents are supplied to the lines PLA and the second driving power line PLB.

However, since an abnormal condition does not occur in the panel 100 , the panel 100 is not damaged during the sensing operation OFF-RS.

When the sensing operation OFF-RS is completed, the power supplied from the power supply unit 500 to the control unit 400 , the gate driver 200 , and the data driver 300 is cut off. Accordingly, the power supplied to the organic light emitting diode display is turned off (S618).

For example, when the control unit 400 transmits a signal indicating that the sensing operation (OFF-RS) has ended to the external system 900 , the external system 900 is supplied to the power supply unit 500 . The power can be cut off. In this case, as described above, the minimum power required for the organic light emitting display device is supplied through the power supply unit 500 , and the control unit 400 , the gate driver 200 , and the data driver 300 . At least one of them may be supplied.

The information stored in the storage unit 450 while the sensing operation OFF-RS is performed is used when the organic light emitting diode display is turned on again and driven.

Finally, as a result of the determination (S614), when an abnormal condition occurs, the control unit 400 stops the sensing operation (OFF-RS) and then sends a signal indicating that the sensing operation (OFF-RS) is stopped. It is transmitted to the external system (900). In this case, the external system 900 may cut off the power supplied to the power supply unit 500 . Accordingly, the power supplied to the organic light emitting display device is turned off (S616).

Those skilled in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential characteristics thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

100: panel 200: gate driver
300: data driver 400: control unit
110: pixel 500: power supply
900: external system

Claims (5)

a panel having pixels, each of which includes an organic light emitting diode and a pixel driving circuit for driving the organic light emitting diode;
a data driver supplying data voltages to data lines provided on the panel;
a gate driver sequentially supplying gate pulses to gate lines provided on the panel; and
a control unit for controlling the data driver and the gate driver;
When a power-off control signal for blocking the image output from the panel is detected, the control unit stops the functions of outputting the image,
When it is determined that an abnormal condition has occurred after the image output is cut off, the control unit cuts off the power supplied to the panel,
The controller performs a sensing operation for compensating for a threshold voltage of a driving transistor provided in the pixel driving circuit after the image output is cut off by the power-off control signal;
When it is determined that the sensed threshold voltage does not deviate from a preset range while performing the sensing operation for compensating for the threshold voltage after the image output is cut off, the control unit supplies to the panel after the sensing operation is terminated cut off the power,
When it is determined that the sensed threshold voltage is out of a preset range while performing the sensing operation for compensating for the threshold voltage after the image output is cut off, the control unit stops the compensation of the threshold voltage and is supplied to the panel An organic light emitting display device that cuts off power. delete The method of claim 1,
The control unit is
a data alignment unit for rearranging input image data transmitted from an external system and supplying the rearranged image data to the data driver;
a control signal generator configured to generate a gate control signal for controlling the gate driver and a data control signal for controlling the data driver; and
and a determination unit for determining whether the abnormal condition has occurred using the sensed data transmitted from the data driver,
The determination unit may generate a power control signal to cut off power supplied to the panel when it is determined that the abnormal condition has occurred. 4. The method of claim 3,
The determination unit transmits the power control signal to a power supply unit for supplying power to driving power lines provided in the panel, the gate driver, and the data driver,
The power supply unit cuts off power supplied to the driving power lines, the gate driver, and the data driver when the power control signal is received. The method of claim 1,
The control unit is a power supply unit that supplies power to the driving power lines provided in the panel, the gate driver, and the data driver when it is determined that an abnormal condition occurs after the image output is cut off, and the power supplied to the panel It transmits a power control signal that cuts off the
The power supply unit cuts off power supplied to the driving power lines, the gate driver, and the data driver when the power control signal is received.

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