KR20160141237A - Method of multi sensing in superpixel and organic light emitting display device applying thereof - Google Patents

Abstract

The present embodiments relate to a multi-sensing method in a super pixel, and an organic light emitting display device using the same. The present embodiments provide an organic light emitting display device including: a display panel having a plurality of super pixels disposed thereon, the plurality of super pixels each including two or more sub-pixels each having an organic light emitting diode and a driving transistor for driving the organic light emitting diode; a gate driver connected to the display panel to apply a signal to a gate line; a data driver connected to the display panel to apply a first data voltage to a first sub-pixel of the super pixel and a second data voltage to a second sub-pixel of the super pixel, and to sense a first sensing voltage from a sensing line to which the first sub-pixel and the second sub-pixel are connected; and a timing controller for controlling the data driver and the gate driver.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a multi-sensing method for super pixels, and an organic light-

The present embodiments relate to a method for multiple sensing in a super pixel and an organic light emitting display using the method.

2. Description of the Related Art [0002] As an information-oriented society develops, there have been various demands for a display device for displaying images. Recently, a liquid crystal display (LCD), a plasma display panel (PDP) Various display devices such as an organic light emitting display (OLED) and the like are being utilized. Such various display apparatuses include display panels corresponding thereto.

2. Description of the Related Art In recent years, an organic light emitting diode (OLED) display device that has been spotlighted as a display device has a high response speed and an excellent contrast ratio, luminous efficiency, luminance, and viewing angle by using an organic light emitting diode (OLED) There are advantages.

Each of the sub-pixels arranged in the organic light emitting display panel of the organic light emitting display device is basically composed of a driving transistor for driving the organic light emitting diode, a switching transistor for transmitting the data voltage to the gate node of the driving transistor, And a capacitor that serves to maintain the capacitor.

On the other hand, the driving transistors in each sub-pixel have characteristic values such as a threshold voltage and a mobility, and these characteristic values may be different for each driving transistor.

In addition, as the driving time becomes longer, the driving transistor is degraded and the characteristic value may be changed. Due to the difference in the degree of deterioration, a characteristic value deviation between the driving transistors may occur.

The deviation of the characteristic values between the driving transistors generates a luminance variation, causing non-uniformity of luminance of the OLED display panel.

Thus, a technique has been developed which senses the characteristic value of the driving transistor to compensate for the deviation between the specific values. However, as the size of the display device increases, the number of the driving transistors increases and the size of the driving transistor decreases, so that the sensing time for grasping the characteristics of the transistor increases in a short period of time and the voltage required for sensing is increased have.

It is an object of the present embodiments to provide an organic light emitting display device and a multiple sensing method which efficiently compensate the mobility of pixels constituting a display panel.

It is another object of the present invention to provide an organic light emitting display and a multiple sensing method for compensating mobility by sensing a data voltage to two or more subpixels connected to one gate line.

It is still another object of the present invention to provide an organic light emitting display and a method of multiple sensing that reduce the size of a data voltage required for sensing by applying a data voltage for sensing to two or more subpixels.

Another object of the present invention is to provide an organic light emitting display device which applies a data voltage for sensing to one subpixel and compensates for the mobility of one subpixel by using another subpixel in the same superpixel as an offset subpixel, And a method for multiple sensing.

Another object of the present invention is to provide an organic light emitting display device and a multiple sensing method which reduce the sensing time for mobility compensation while reducing the size of a data voltage without requiring additional circuits or components.

One embodiment provides a display panel including a plurality of super pixels including two or more sub pixels including an organic light emitting diode and a driving transistor for driving the organic light emitting diode, A gate driver connected to the display panel for applying a first data voltage to a first subpixel of the superpixel and a second data voltage to a second subpixel of the superpixel and applying a second data voltage to the sensing line connected to the first subpixel and the second subpixel, And a timing controller for controlling the data driver and the gate driver.

According to another embodiment of the present invention, there is provided a display panel including a plurality of super pixels including two or more sub-pixels including an organic light emitting diode and a driving transistor for driving the organic light emitting diode, A gate driver for applying a signal for sensing to the gate line, a gate driver connected to the gate line to which the signal is applied, And applying K first data voltages compensated to each of K first subpixels connected to K first data lines and K first subpixels connected to K second data lines, A data driver for sensing a first sensing voltage for each of the second subpixels in the K sensing lines, It provides an OLED display including a timing controller for controlling the driver.

In another embodiment, the gate driver applies a signal for sensing to one gate line, the data driver applies a first data voltage to a first sub-pixel connected to the gate line and connected to one sensing line, Applying a second data voltage to a second sub-pixel connected to the sensing line, the data driver senses a first sensing voltage at a sensing line, the data driver or timing controller uses a first sensing voltage to generate a second sub- And compensating a characteristic value of the organic light emitting display device.

According to the embodiments of the present invention as described above, in order to compensate the mobility of transistors constituting the subpixel, a data voltage is applied to two or more subpixels connected to one sensing line, Thereby lowering the data voltage.

According to the embodiment of the present invention, an increase in the data voltage at the time of sensing due to the size reduction of the driving transistor is suppressed, thereby preventing an overflow of the data voltage.

According to the embodiment of the present invention, since the data voltage can be applied within the normal range even if the size of the driving transistor is reduced, the effect of increasing the accuracy of mobility compensation is provided.

1 is a system configuration diagram of an organic light emitting display according to the present embodiments.
FIG. 2 is a diagram illustrating a subpixel circuit and a subpixel compensation circuit of an organic light emitting diode display according to an embodiment of the present invention. Referring to FIG.
3 is a view for explaining the threshold voltage sensing principle of the driving transistor DRT of the OLED display 100 according to the present embodiments.
4 and 5 are diagrams for explaining the principle of mobility sensing for the driving transistor DRT of the OLED display 100 according to the present embodiments.
6 is a diagram illustrating a structure for applying a data voltage to two subpixels in sensing one subpixel according to an embodiment of the present invention.
7 is a diagram illustrating two sensing voltages applied to a sensing line according to an embodiment of the present invention.
8 is a diagram illustrating an organic light emitting display device for sensing subpixels of two data lines according to an embodiment of the present invention.
9 is a diagram illustrating an embodiment of applying a data voltage to two subpixels in one superpixel for multi-line sensing according to an exemplary embodiment of the present invention.
10 is a diagram illustrating a process of performing multi-line sensing in each sensing line according to an embodiment of the present invention.
11 and 12 illustrate an embodiment in which two or more subpixels in one superpixel according to an exemplary embodiment of the present invention are selected and detected as offset subpixels.
FIG. 13 is a diagram comparing the rise of the data voltage in the case of sensing one conventional subpixel and the case of sensing using the offset subpixel according to the present invention.
FIG. 14 is a diagram illustrating a process of performing single-line sensing and multi-line sensing for each color of sub-pixels according to an embodiment of the present invention.
FIG. 15 is a flowchart illustrating a mobility sensing process performed during a blank time according to an exemplary embodiment of the present invention. Referring to FIG.
16 is a graph showing a relationship between a current and a voltage in a sensing process according to an embodiment of the present invention.
17 is a diagram illustrating a process of applying and sensing signals and data voltages for multi-sensing by a data driver and a gate driver in an organic light emitting display according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the components from other components, and the terms do not limit the nature, order, order, or number of the components. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; intervening "or that each component may be" connected, "" coupled, "or " connected" through other components.

FIG. 1 is a schematic system configuration diagram of an organic light emitting diode display 100 according to the present embodiments.

1, the OLED display 100 according to the present embodiment includes a plurality of data lines DL1 to DLm and a plurality of gate lines GL1 to GLn, A data driver 120 connected to the upper or lower end of the display panel 110 and driving a plurality of data lines DL1 to DLm; A timing controller 140 for controlling the data driver 120 and the gate driver 130, and the like.

Referring to FIG. 1, a plurality of subpixels SP are arranged in a matrix type on a display panel 110.

Accordingly, a plurality of sub pixel lines exist in the display panel 110, and the sub pixel lines may be sub pixel rows or sub pixel columns. In the following, subpixel rows are described as subpixel lines.

The data driver 120 drives the plurality of data lines DL1 to DLm by supplying data voltages to the plurality of data lines DL1 to DLm. Here, the data driver 120 is also referred to as a source driver. The gate driver 130 sequentially drives the plurality of gate lines GL1 to GLn by sequentially supplying scan signals to the plurality of gate lines GL1 to GLn. Here, the gate driver 130 is also referred to as a scan driver.

The timing controller 140 supplies various control signals to the data driver 120 and the gate driver 130 to control the data driver 120 and the gate driver 130.

The timing controller 140 starts scanning in accordance with the timing implemented in each frame and switches the input image data inputted from the outside according to the data signal format used by the data driver 120, And controls the data driving at a proper time according to the scan.

The gate driver 130 sequentially supplies a scan signal of an On voltage or an Off voltage to the plurality of gate lines GL1 to GLn in accordance with the control of the timing controller 140, (GL1 to GLn) sequentially.

1, the gate driver 130 may be located only on one side of the display panel 110 or on both sides depending on the driving method, the panel designing method, and the like. In addition, the gate driver 130 may include one or more gate driver integrated circuits (GDICs).

When the specific gate line is opened, the data driver 120 converts the image data Data received from the timing controller 140 into analog data voltages Vdata and supplies them to the plurality of data lines DL1 to DLm , And drives the plurality of data lines DL1 to DLm.

The data driver 120 may drive a plurality of data lines including at least one source driver integrated circuit (SDIC).

Each of the gate driver integrated circuits or source driver integrated circuits may be connected to a bonding pad of the display panel 110 by a tape automated bonding (TAB) method or a chip on glass (COG) method , And may be directly disposed on the display panel 110, or may be integrated and disposed on the display panel 110 as occasion demands.

Each source driver integrated circuit may include a logic portion including a shift register, a latch circuit, etc., a digital analog converter (DAC), an output buffer, and the like, (310 in FIG. 3) for sensing the characteristics of the subpixel in order to compensate for, for example, the threshold voltage and the mobility of the driving transistor, the threshold voltage of the organic light emitting diode, and the luminance of the subpixel) .

In addition, each source driver integrated circuit may be implemented by a chip on film (COF) method. In this case, one end of each source driver integrated circuit is bonded to at least one source printed circuit board, and the other end is bonded to the display panel 110.

On the other hand, the timing controller 140 includes a vertical synchronizing signal Vsync, a horizontal synchronizing signal Hsync, an input data enable (DE) signal, a clock signal CLK, and the like And receives various timing signals from the outside (e.g., the host system).

The timing controller 140 may switch the input video data input from the outside in accordance with the data signal format used by the data driver 120 and output the converted video data Data, In order to control the driver 130, a timing signal such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, an input DE signal, and a clock signal is received to generate various control signals, And outputs it to the driver 130.

For example, in order to control the gate driver 130, the timing controller 140 generates a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable signal GOE : Gate Output Enable), and the like.

Here, the gate start pulse GSP controls the operation start timing of one or more gate driver integrated circuits constituting the gate driver 130. The gate shift clock GSC is a clock signal commonly input to one or more gate driver integrated circuits, and controls the shift timing of the scan signal (gate pulse). The gate output enable signal GOE specifies the timing information of one or more gate driver ICs.

The timing controller 140 includes a source start pulse SSP, a source sampling clock SSC and a source output enable signal SOE to control the data driver 120. [ Output enable (DCS) data control signals.

Here, the source start pulse SSP controls the data sampling start timing of one or more source driver integrated circuits constituting the data driver 120. The source sampling clock SSC is a clock signal for controlling sampling timing of data in each of the source driver integrated circuits. The source output enable signal SOE controls the output timing of the data driver 120.

1, the timing controller 140 includes a source printed circuit board on which at least one source driver integrated circuit is bonded, a flexible flat cable (FFC) or a flexible printed circuit (FPC) May be disposed on a control printed circuit board (PCB) connected via a connection medium.

The organic light emitting diode display 100 according to the present embodiment is an organic light emitting display device in which each sub pixel SP includes an organic light emitting diode (OLED) And a transistor (DRT: Driving Transistor). The types and the number of the circuit elements constituting each subpixel SP can be variously determined depending on the providing function, the design method, and the like.

On the other hand, in the organic light emitting diode display 100, circuit elements such as the organic light emitting diode OLED and the driving transistor DRT are deteriorated as the driving time of each subpixel SP becomes longer, Inherent characteristic values (e.g., threshold voltage, mobility, etc.) of the circuit elements such as the diode OLED and the driving transistor DRT are changed.

The degree of change in the characteristic value between the circuit elements may be different due to the difference in degree of deterioration between the circuit elements.

Due to such characteristic deviations of the circuit elements, a luminance deviation may occur between the sub-pixels SP. Accordingly, the luminance uniformity of the display panel 110 is deteriorated, and the image quality may be deteriorated.

Accordingly, the organic light emitting diode display 100 according to the present embodiments can provide a "pixel compensation function" for compensating a characteristic value deviation of a circuit element between subpixels SP.

In the organic light emitting diode display 100 according to the present embodiments, each subpixel SP has a structure capable of sensing the subpixel characteristic value and compensating for the subpixel characteristic value deviation.

In addition, the OLED display 100 according to the exemplary embodiments of the present invention includes a sensing configuration for sensing a sub-pixel characteristic value to provide a sub-pixel compensation function, a sensing configuration for sensing a characteristic value deviation between sub- To compensate for < / RTI >

Here, the subpixel characteristic value may include, for example, a characteristic value such as a threshold voltage of the organic light emitting diode OLED, a threshold voltage of the driving transistor DRT, a characteristic value such as mobility, and the like. In the following, the threshold voltage and the mobility of the driving transistor DRT are exemplified as the sub-pixel characteristic values.

2 is a diagram illustrating a subpixel circuit and a subpixel compensation circuit of the organic light emitting diode display 100 according to the present embodiments.

2, the sub-pixel circuit 201 will be described first. The subpixel is a subpixel that receives the data voltage (Vdata) from the i-th data line (DLi, 1? I? M), and is capable of sensing the subpixel characteristic value and compensating for the subpixel characteristic value deviation have.

Referring to FIG. 2, each sub-pixel of the OLED display 100 according to the present embodiment includes an organic light emitting diode (OLED) and a driving circuit for driving the organic light emitting diode OLED.

The driving circuit may include a driving transistor DRT, a switching transistor SWT, a sensing transistor SENT, and a storage capacitor Cst.

The driving transistor DRT drives the organic light emitting diode OLED by supplying a driving current to the organic light emitting diode OLED and the driving transistor DRT is driven to supply the driving voltage EVDD with the organic light emitting diode OLED. Voltage lines (DVL). The driving transistor DRT has a first node N1 corresponding to a source node or a drain node, a second node N2 corresponding to a gate node, and a third node N3 corresponding to a drain node or a source node.

The switching transistor SWT is connected between the data line DLi and the second node N2 of the driving transistor DRT and is turned on by receiving the scan signal SCAN to the gate node. The switching transistor SWT is turned on by the scan signal SCAN to transfer the data voltage Vdata supplied from the data line DLi to the second node N2 of the driving transistor DRT.

The sensing transistor SENT is connected between a first node N1 of the driving transistor DRT and a reference voltage line RVL for supplying a reference voltage VREF and supplies a sensing signal SENSE ) And is turned on. The sensing transistor SENT is turned on by the sensing signal SENSE to apply the reference voltage VREF supplied through the reference voltage line RVL to the first node N1 of the driving transistor DRT. Also, the sensing transistor SENT can also serve as a sensing path so that the sensing configuration can sense the voltage of the first node N1 of the driving transistor DRT.

The scan signal SCAN and the sense signal SENSE may be respectively applied to the gate node of the switching transistor SWT and the gate node of the sensing transistor SENT through another gate line.

In some cases, the scan signal SCAN and the sense signal SENSE may be the same signal and may be respectively applied to the gate node of the switching transistor SWT and the gate node of the sensing transistor SENT through the same gate line.

The OLED display 100 according to the present embodiment includes a sensing unit 310 for sensing a subpixel characteristic value and a sensing unit 310 for sensing a subpixel characteristic of the sensing unit 310. [ A memory 320 for storing the result, and a compensation unit 330 for compensating for the deviation of the sub-pixel property value. For example, the sensing unit 310 may be included in the source driver integrated circuit, and the compensating unit 330 may be included in the timing controller 140.

The organic light emitting diode display 100 according to the present exemplary embodiment is configured to control the driving of the driving transistor DRT within the subpixel SP by controlling the voltage application state of the first node N1 in the subpixel SP, And may further include a switch SW for controlling the state necessary for sensing. One end Nc of the reference voltage line RVL may be connected to the reference voltage supply node Na or the node Nb of the sensing unit 310 through the switch SW.

The reference voltage line RVL is basically a line for supplying the reference voltage VREF to the first node N1 of the driving transistor DRT via the sensing transistor SENT. Meanwhile, a line capacitor Cline is formed in the reference voltage line RVL. The sensing unit 310 senses a voltage charged in the line capacitor Cline on the reference voltage line RVL at a necessary time. Therefore, in the following, the reference voltage line RVL is also referred to as a sensing line.

The reference voltage lines RVL may be arranged, for example, one for each sub-pixel column, or one for each of two or more sub-pixel columns.

For example, if one pixel is composed of four subpixels (red subpixel, white subpixel, green subpixel, and blue subpixel), one pixel may be arranged for each one pixel column.

The sensing unit 310 includes a sensing line electrically connected to a first node N1 of a driving transistor DRT in a sub-pixel on a sensing sub-pixel line (SSPL) in which sensing driving is performed among a plurality of sub- RVL), and outputs a sensing value, thereby performing the sensing process.

The sensing unit 310 can sense the voltage charged in the line capacitor Cline on the sensing line RVL by the current flowing to the sensing line RVL.

Here, the voltage charged in the line capacitor Cline is the voltage of the sensing line RVL, and the first node N1 of the driving transistor DRT, which reflects the characteristic value (threshold voltage, mobility) ).

The voltage of the first node N1 of the driving transistor DRT is stored in the line capacitor Cline and the sensing unit 310 changes the voltage of the first node N1 of the driving transistor DRT directly Sensing the charging voltage of the line capacitor Cline storing the voltage of the first node N1 of the driving transistor DRT and not sensing the charging voltage of the driving transistor DRT even when the sensing transistor SENT is turned off, DRT) of the first node N1.

Each sub-pixel may be driven for threshold voltage sensing of the driving transistor DRT and for driving the driving transistor DRT.

The sensing value sensed by the sensing unit 310 may be a sensing value for sensing the threshold voltage Vth of the driving transistor DRT or a sensing value for sensing the mobility of the driving transistor DRT. have.

When the subpixel is driven for the threshold voltage sensing of the driving transistor DRT, in accordance with this threshold voltage sensing driving, the first node N1 and the second node N2 of the driving transistor DRT, respectively, The first node N1 of the driving transistor DRT is floated so that the voltage of the first node N1 of the driving transistor DRT becomes equal to the reference voltage VREF The voltage of the first node N1 of the driving transistor DRT becomes saturated.

At this time, the saturated voltage Vdata-Vth of the first node N1 of the driving transistor DRT is charged in the line capacitor Cline on the sensing line RVL.

The sensing unit 310 senses the voltage charged in the line capacitor Cline when the sensing timing (sampling timing) is reached. At this time, the sensed voltage Vsense corresponds to a voltage obtained by subtracting the threshold voltage Vth of the driving transistor DRT from the data voltage Vdata.

When the subpixel is driven for the threshold voltage sensing of the driving transistor DRT, the first node N1 and the second node N2 of the driving transistor DRT are driven by the threshold voltage sensing The driving data voltage Vdata and the reference voltage VREF are initialized and then the first node N1 and the second node N2 of the driving transistor DRT both float and the voltage rises.

At this time, the voltage rising rate (the amount of change in the voltage rising value with respect to time) indicates the current capability, i.e., mobility, of the driving transistor DRT. Therefore, the voltage of the first node N1 of the driving transistor DRT increases more sharply as the driving transistor DRT having a larger current capability (mobility) is.

The line capacitor Cline on the sensing line RVL is charged by the current flowing to the sensing line RVL through the driving transistor DRT in accordance with the voltage rise.

The sensing unit 310 senses the voltage Vsense charged in the line capacitor Cline on the sensing line RVL.

The memory 320 may store a sensing value for each sensing sub-pixel line SSPL by a predetermined number N of sensing sub-pixel lines.

The predetermined number N of sensing subpixel lines may be equal to the number of all subpixel lines existing in the display panel 110 in accordance with the usable capacity of the memory 320 or the like, It is possible.

In the following description, the predetermined number N of sensing subpixel lines is limited to the case where the number is less than the number of all subpixel lines. Illustratively, the number of sensing subpixel lines (N) is illustratively 35.

For example, when the organic light emitting diode display 100 has an RWGB pixel structure and has a resolution of 1920 x 1080 (i.e., m = 4 x 1920, n = 1080), only 35 sub- Sensing sub-pixel line.

The compensation unit 330 can perform property value compensation processing by grasping a characteristic value (e.g., threshold voltage, mobility) of the driving transistor DRT in the corresponding subpixel based on the sensing value stored in the memory 320. [

The characteristic value compensation process may include threshold voltage compensation processing for compensating a threshold voltage of the driving transistor DRT and mobility compensation processing for compensating mobility of the driving transistor DRT, . ≪ / RTI > The above-described characteristic value compensation processing function can be provided by either the data driver or the timing controller.

In the threshold voltage compensation process, a compensation value (threshold voltage compensation value) for compensating the threshold voltage is calculated, the calculated compensation value is stored in the memory 320, or the corresponding video data Data is changed with the calculated compensation value Processing.

The mobility compensation process may include a process of calculating a compensation value for compensating the mobility, storing the calculated compensation value in the memory 320, or changing the corresponding image data Data with the calculated compensation value .

The compensation unit 330 may change the image data Data through the threshold voltage compensation process or the mobility compensation process and supply the changed data to the source driver integrated circuit.

At this time, a digital analog converter (DAC) 300 in the source driver integrated circuit converts the data voltage Vdata corresponding to the analog voltage and supplies the converted data voltage to the corresponding subpixel so that characteristic value compensation (threshold voltage compensation, mobility compensation ) Is actually applied.

Through the compensator 330 described above, the characteristic value of the driving transistor can be compensated to reduce or prevent the luminance deviation between the subpixels.

Hereinafter, the principle of sensing the threshold voltage (Vth) of the driving transistor DRT in order to compensate for the threshold voltage deviation between the driving transistors DRT will be briefly described with reference to FIG. Next, the principle of sensing the mobility of the driving transistor DRT in order to compensate for the mobility deviation between the driving transistors DRT will be briefly described with reference to FIG.

The sensing unit 310 may be implemented as an analog digital converter (ADC) for converting an analog voltage value into a digital value.

3 is a view for explaining the threshold voltage sensing principle of the driving transistor DRT of the OLED display 100 according to the present embodiments. However, it is assumed that the first node N1 of the driving transistor DRT is the source node. The voltage Vs of the source node N1 of the driving transistor DRT is controlled by the source follower which follows the voltage Vg of the gate node N2 The voltage Vs of the source node N1 of the driving transistor DRT is set to the sensing voltage Vsense after the voltage Vs of the source node N1 of the driving transistor DRT becomes saturated. As shown in Fig. At this time, the threshold voltage variation of the driving transistor DRT can be grasped based on the sensed sensing voltage Vsense.

The threshold voltage sensing of the driving transistor DRT is characterized in that the sensing speed is slow because it must wait until the driving transistor DRT is turned off. Therefore, the threshold voltage sensing mode is also referred to as a slow mode (S-Mode).

The voltage Vg applied to the gate node N2 of the driving transistor DRT is the data voltage Vdata supplied from the corresponding source driver IC SDIC. The characteristic value compensation for compensating the threshold voltage or the mobility of the driving transistor may be performed by any one of the data driver and the timing controller, but the present invention is not limited thereto.

4 and 5 are diagrams for explaining the principle of mobility sensing for the driving transistor DRT of the OLED display 100 according to the present embodiments.

4, the principle of the mobility sensing for the driving transistor DRT will be briefly described. A voltage obtained by adding a constant voltage? To the data voltage Vdata is applied to the gate node N2 of the driving transistor DRT. Here, the constant voltage? Is a voltage corresponding to the threshold voltage compensation value.

Thus, the current capability (i.e., mobility) of the driving transistor DRT can be relatively grasped through the amount of voltage (? V) charged in the line capacitor Cline for a predetermined period of time, Gain is obtained.

This mobility sensing is characterized in that the sensing speed is fast because the driving transistor DRT is basically turned on. Therefore, the mobility sensing mode is also referred to as a fast mode (F-Mode).

The mobility compensation through the above-described mobility sensing can be performed by allocating a predetermined time during the screen driving. By doing so, the parameters of the driving transistor DRT varying in real time can be sensed and compensated.

5 is a graph showing the voltage change of the first node N1 of the driving transistor DRT according to the sensing time during the mobility sensing operation. For sensing the mobility, the sensing value sensed by the sensing unit 310 is converted to a digital value.

The sensing unit 310 has an analog-to-digital conversion range (ADC Range) from a digital value (0) corresponding to m [V] to a digital value 1023 corresponding to M [V].

The sensing values for all the subpixels in the display panel 110 have any distribution 500. This distribution 500 corresponds to the distribution of the mobility of the driving transistor DRT in all subpixels in the display panel 110. [

If the sensing value X [V] sensed in any sub-pixel differs from the reference value REF_TARGET, the compensating unit 320 changes the original data to a compensation value corresponding to the difference, Can be achieved.

On the other hand, in the high-resolution model, the pixel size is reduced and the size of the driving transistor is minimized in order to secure the aperture ratio. This may result in a longer sensing time due to the decrease of the current capability. In order to solve this problem, for example, in order to carry out sensing for mobility compensation within a short time, Vdata applied to the subpixel must be increased, which leads to reduction of the threshold voltage (Vth) compensation margin, . 5, when only the white subpixels are sensed, a value obtained by adding Vdata and the threshold voltage compensation value? Of the white subpixel may be higher than the range of voltages that the data driver IC can output (Vdata + Φ> D-IC output range).

In addition, as the process of sensing and compensating mobility progressing in the blank time increases the size of the display panel, the number of lines to be sensed increases, and the time required to perform the mobility sensing for the entire panel increases. This is also a problem that needs to be raised in Vdata.

Hereinafter, a method of increasing the sensing speed while lowering the Vdata in the process of compensating mobility even in a large-sized display panel will be described. For this purpose, a case in which a data voltage for sensing driving is applied to a data line of one subpixel among the subpixels connected to one sensing line is referred to as a single line sensing, and a case where two or more subpixels The case of applying the data voltage for the sensing drive to the data line of FIG.

More specifically, it allows one subpixel to operate as a current source between subpixels sharing one sensing line. In one embodiment, the driving transistor (DR TFT) of one sub pixel other than the sub pixel to be actually sensed in one super pixel operates as a current source that allows a constant current to flow, and the VREF value (OFF-SET) to reduce the Vdata voltage which is actually sensed. That is, a data voltage required to sense one subpixel is provided as an offset voltage using a data voltage applied to a subpixel sharing the same sensing line.

In one embodiment of the present invention, in sensing one of the two subpixels connected to the same sensing line, the driving transistor of the other subpixel may be used as a current source to lower the data voltage required for the subpixel sensing.

6 is a diagram illustrating a structure for applying a data voltage to two subpixels in sensing one subpixel according to an embodiment of the present invention.

The data voltage of the first voltage is applied to the first subpixel 610 whose mobility compensation is completed in FIG. The first voltage is applied with a constant data voltage Vdata_offset based on Vdata +? 1 applied with at least one of the threshold voltage compensation value or the mobility compensation value of the first subpixel 610. [ On the other hand, the second subpixel 620 to be sensed has a constant ratio Vdata +? _2 based on the data voltage Vdata +? _2 of the second voltage to which? 2 applied by the previous mobility compensation or the threshold voltage compensation value is added The data voltage Vdata_main is applied. Assuming that the data voltage to be applied to sense the second subpixel 620 without a current source is Vdata_sin, the following relationship holds.

[Equation 1]

Vdata_sin = Vdata_offset + Vdata_main

Vdata_offset = (Vdata +? 1) * offset_percentage

Vdata_main = (Vdata +? 2) * main_percentage

Here, Vdata is a data voltage applied during sensing driving, and the mobility of each subpixel or the threshold voltage compensation values? 1 and? 2 are reflected. And offset_percentage indicates how much current source the first subpixel 610 is used for mobility compensation. For example, when the Vdata to be applied when single-line sensing the second subpixel 620 is 4V, Vdata_offset can be set to 1V and Vdata_main to 3V. In this case, offset_percentage is 0.25 and main_percentage is 0.75.

The voltage sensed in the sensing line from the two subpixels 610 and 620 in the sensing line is divided into two voltages Vref_offset and Vref_offset which are sensed by the first subpixel 610 and the second subpixel 620, Vref_main, which is the second sensing voltage sensed in the sensing line, is added and sensed in the sensing line.

7 is a diagram illustrating two sensing voltages applied to a sensing line according to an embodiment of the present invention. Vref, which is the voltage sensed in the sensing line, is added to two voltages: Vsen_offset, which is the first sensing voltage sensed in the first subpixel 610, and Vsen_main, which is the second sensing voltage sensed in the second subpixel 620 Vsen_total is sensed on the sensing line. The mobility for the second subpixel can be compensated using Vsen_offset + Vsen_main sensed in the sensing line.

6 and 7, the problem of output data voltage overflow due to the size of the driving transistor can be solved when a voltage is applied to only the data line of the corresponding subpixel in order to sense one subpixel (Vdata_main < D-IC output range).

6 and 7, there is one sensing voltage sensed in one sensing line, but it is possible to accurately grasp the sensing voltage amount of the offset subpixel in which mobility or threshold voltage is compensated, The amount of the sensing voltage contributed by the pixel can be calculated. Therefore, even when the data voltage is not excessively increased, the sensing voltage of the sub-pixel can be accurately sensed and the mobility through the sensing voltage can be compensated.

Hereinafter, an OLED display device according to an embodiment of the present invention includes a display panel, a gate driver, a data driver, and a timing controller for controlling the display panel, the data driver, and the display driver. The gate driver applies a signal to one gate line, and the data driver conducts sensing for a plurality of subpixels connected thereto.

In one embodiment of the present invention, a plurality of super pixels including two or more sub pixels are disposed on a display panel, and one super pixel is connected to one sensing line. That is, two or more subpixels connected to the same sensing line are referred to as superpixels. Also, the above-described super pixels may be connected to the same gate line and may include two or more sub pixels connected to the same sensing line.

Therefore, when the number of subpixels constituting the superpixel is M, there may be a data line of (M * K) times the number of sensing lines (for example, K) multiplied by M. In one embodiment of the present invention, the sensing voltage is checked in the entire sensing line (K), and the data voltage is applied to the two or more subpixels for each superpixel such as 2 * K or 3 * Voltage is applied. Even if two or more data voltages are applied to sense the sum of the sensing voltages from two subpixels, the sensing voltage provided by the offset subpixel can be calculated in advance. Therefore, the sensing voltage of the target subpixel The voltage can be calculated.

8 is a diagram illustrating an organic light emitting display device for sensing subpixels of two data lines according to an embodiment of the present invention. For convenience of explanation, the data lines are not shown, and the sensing lines SL [0] to SL [p-1] are connected to four pairs of sub-pixels. The data driver 120 may again be divided into several source driver ICs. The data driver 120 also includes a plurality of sensing units 310a to 310z including an analog-to-digital converter (ADC) for converting Vref sensed in each sense line into a digital value, that is, converting an analog voltage value into a digital value can do. Each of the sensing units is connected to a predetermined number of sensing lines (e.g., 2, 3, 4, or more natural numbers).

First, in FIG. 8, the data driver 120 under the control of the timing controller 140 or the timing controller 140 determines a subpixel to which the offset data voltage is to be applied and a subpixel to be actually sensed within one superpixel. In one embodiment of determining the subpixel to which the offset data voltage is to be applied, the subpixel with the latest mobility compensation can be selected. In another embodiment, the subpixel having the largest driving transistor size and mobility compensation can be selected as a subpixel to which the offset data voltage is to be applied. In another embodiment, a subpixel representing a particular color may be selected as the subpixel to which the offset data voltage is to be applied. In one embodiment, a second subpixel among the superpixels is selected as a subpixel (offset subpixel) to which an offset data voltage is to be applied, and an example in which a subpixel (sensing subpixel) to be actually sensed is selected as a third subpixel is shown in FIG. see.

9 is a diagram illustrating an embodiment of applying a data voltage to two subpixels in one superpixel for multi-line sensing according to an exemplary embodiment of the present invention. An offset data voltage Vdata_offset_0 is applied to an offset subpixel connected to DL_offset [0], and a main data voltage Vdata_main_0 is applied to a sensing subpixel connected to DL_offset [0]. Both the offset sub-pixel and the sensing sub-pixel are connected to one sensing line SL [0]. The same applies to other sensing lines. The offset data voltage Vdata_offset_k is applied to the offset subpixel k connected to the DL_offset [k], and the main data voltage Vdata_main_k is applied to the sensing subpixel connected to the DL_offset [k]. In this manner, the offset data voltages are applied to the total of p offset subpixels, respectively, and the main data voltages are applied to all the ppixel sensing subpixels. The offset data voltage may be applied equally to all p offset subpixels and different offset voltages may be applied resulting from compensating the mobility or threshold voltage of each offset subpixel.

10 is a diagram illustrating a process of performing multi-line sensing in each sensing line according to an embodiment of the present invention. 9, an offset sensing voltage applied to the sensing line through the offset sub-pixel and a sensing voltage applied to the sensing line through the sensing sub-pixel are added to the sensing units 310a through 310z, .

For example, the offset sensing voltage Vsen_offset_0 is sensed in an offset sub-pixel connected to SL [0] and the main sensing voltage Vsen_main_0 is sensed in a sensing sub-pixel connected to the same SL [0] ], The sum Vsen_total_0 is sensed. The same applies to other sensing lines as well. In other words, the offset sensing voltage Vsen_offset_k is sensed in the offset subpixel connected to SL [k], and the main sensing voltage Vsen_main_k is sensed in the sensing subpixel connected to the same SL [k] Quot; Vsen_total_k &quot; The sensing units 310a to 310z compute the mobility of the sensing subpixel by comparing the sensed voltage with a reference voltage. Since the offset subpixel has been compensated for the mobility or the threshold voltage previously, the compensation unit 330 compensates the characteristic value for each sensing subpixel, for example, mobility compensation using the sensed voltage Vsen_total_k. The characteristic value compensation described above may be provided by either one or both of the timing controller and the data driver, which may be variously selected depending on the manner of configuring the timing controller and the data driver.

9 and 10, the data driver 120 is connected to the display panel to apply the first data voltage to the first sub-pixel of the super pixel and the second data voltage to the second sub-pixel of the super pixel, The first sensing voltage is sensed in the sensing line to which the subpixel and the second subpixel are coupled to compensate the mobility of the second subpixel to lower the data voltage required for sensing the second subpixel, To improve the accuracy of sensing.

In one embodiment of the present invention, the offset sensing voltage Vsen_offset_k may be configured to be all the same in order to make the mobility compensation for the sensing subpixels uniform. For this purpose, the offset data voltage can accurately reflect the mobility or threshold voltage compensation value of each offset subpixel. In one embodiment, the data driver 120 may calculate the first compensation value by completing at least one of mobility compensation or threshold voltage compensation for the first subpixel before compensating the mobility of the second subpixel One result can be applied. As a result, the actual sensed value is the result of sensing in two subpixels, but the contribution of the first subpixel, which is an offset subpixel, to the sensed voltage can be grasped accurately, and thus the sensing accuracy of the second subpixel can be increased .

In the case of applying the present invention, in compensating the mobility of the driving transistor of the OLED pixel constituting the high-resolution display device, the size of the pixel is reduced and the size of the driving transistor (DR-TFT) of the OLED is reduced The mobility of the driving transistor can be compensated accurately. When the mobility sensing is performed in the vertical blank time, the sensing operation must be performed in a short time. Therefore, the data voltage for sensing must be increased. However, when the embodiment of the present invention is applied, It is possible to lower the data voltage applied to one sub-pixel by applying a data voltage to each of the sub-pixels. The sensing value is a voltage formed by two or more subpixels, but one or more of the subpixels may be driven to act as an offset to substantially compensate for the mobility characteristic of only one subpixel.

6 to 10, in an embodiment of the present invention, in addition to one sub-pixel (sensing sub-pixel) sensing to compensate mobility within one super-pixel sharing one sensing line, (Offset sub-pixels) are driven to raise the sensing value to a certain level.

The offset voltage is applied to the driving transistor of the offset subpixel to compensate for the threshold voltage and the mobility, so that all the offsets in the panel can be equalized.

The present invention can apply a data voltage to one or more offset subpixels and a single sensing subpixel, respectively, in order to lower the data voltage applied when sensing the mobility of the driving transistor. As an offset subpixel, it is possible to select a subpixel in which the data voltage is relatively low, that is, the size of the driving transistor is relatively large. On the other hand, the sensing subpixel can select a subpixel in which the data voltage is relatively high, that is, the driving transistor is relatively small in size. Further, the offset subpixel can select one or more. The offset subpixel can select a subpixel whose mobility or threshold voltage compensation has been completed. R subpixels can be used as offset subpixels in an RWGB structure that constitutes superpixels with offset subpixels of a specific color, for example, red / white / green / blue.

11 and 12 illustrate an embodiment in which two or more subpixels in one superpixel according to an exemplary embodiment of the present invention are selected and detected as offset subpixels.

In sensing a subpixel 1110 in a superpixel composed of a plurality of subpixels, a data voltage is applied to two offset subpixels 1121 and 1122. All three subpixels are connected to one sensing line SL [k]. In order for the first offset sub-pixel 1121 to operate as a current source, Vdata_offset1 is applied to DL_offset1 [k] which is a data line. In order for the second offset sub-pixel 1122 to operate as a current source, Vdata_offset2 is applied to the data line DL_offset2 [k]. And Vdata_main is applied to the data line DL_main [k] to which the subpixel 1110 to be sensed is connected. Since the offset subpixels 1121 and 1122 are all compensated for the mobility and the threshold voltage, the magnitude of the voltage applied to the sensing line SL [k] through the driving transistor of the subpixel through the offset subpixel is Is calculated in advance. This will be described with reference to FIG.

In FIG. 12, in each offset sub-pixel, a sensing voltage is applied to the sensing line corresponding to applied data voltages. Since the offset subpixels 1121 and 1122 are compensated for the mobility and the threshold voltage, the values of Vsen_offset1 and Vsen_offset2, which are the sensing voltages applied to the sensing line SL [k] in the driving transistor of each offset subpixel, have. Therefore, except for the sensing voltages Vsen_offset1 and Vsen_offset2, which are the sensing voltages provided by the offset subpixels in the entire sensed value Vsen_total, the sensing voltage Vsen_main, which is applied to the sensing line SL [k], is checked in the subpixel 1110 to be sensed And the mobility of the driving transistor of the sub-pixel 1110 can be compensated based on this.

11 and 12, two offset sub-pixels are used. However, the present invention is not limited thereto. The present invention can be applied to any one of sub-pixels sensing among a plurality of sub- And selecting one or more of the other subpixels as a current source source for &lt; / RTI &gt;

It is possible to control the data voltage applied to the sub-pixel to be sensed to be outputted within the output voltage range of the source driver IC when the technical structure or the embodiment as described above is applied. Since the other subpixels are used as the current sources, the data voltage is stably applied within the output voltage range. Therefore, it is possible to precisely compensate the mobility of the driving transistor by eliminating the possibility of malfunction when compensating the mobility. In addition, since the data voltage does not overflow even if the size of the driving transistor is reduced, the mobility compensation is accurate, and as a result, the defective stain is eliminated and the image quality is improved.

Particularly, for example, in the conventional process of compensating the mobility of the driving transistor for a short time such as a vertical blank time, the data voltage must be increased in order to allow the sensed voltage to fall within a proper range of ADC (Analog Digital Converting) The output voltage range of the source driver IC could be exceeded. However, by adjusting the data voltage to output a certain sensing voltage at one or more offset subpixels, the sensing voltage can be confirmed at two subpixels. This will be described in more detail in FIG.

FIG. 13 is a diagram comparing the rise of the data voltage in the case of sensing one conventional subpixel and the case of sensing using the offset subpixel according to the present invention.

Reference numeral 1310 denotes a case of sensing one subpixel. The sum of the voltages Vdata and Vth compensation exceeds the voltage range (D-IC Range) that can be output from the data driver. For example, if the output range is 10V and the voltage for Vth compensation is 4V, if the current capability of the driving transistor is reduced due to a decrease in size of the driving transistor, Vdata may increase inversely. If Vdata increases to 8V, an overflow of 2V occurs as in 1310. If Vdata goes beyond the output voltage, mobility compensation will not work properly, improper compensation may cause stain defect and image quality degradation. In particular, when implementing a high-resolution / large-sized panel, the capacitance of the sensing line may increase, which has been a factor for increasing the Vdata in the mobility sensing / compensation process.

1320 shows a case where the data voltage applied to the sub-pixel to be sensed by applying the data voltage to at least one offset sub-pixel and one sensing sub-pixel does not exceed the voltage range (D-IC Range) outputable by the data driver. As described above, since a certain portion of the sensing voltage is also contributed to the offset subpixel, Vdata 'to be applied for sensing in the sensing subpixel is reduced. As a result, Vdata 'is output within a range that can be output from the driver as indicated by 1320.

Conventionally, the sensing for mobility compensation has been performed on the subpixels connected to one gate line at the vertical blank time. In the case of applying the present invention, since the data voltage is applied to both the subpixel to be sensed at the blank time and the offset subpixel and the output time to the sensing voltage is shortened, mobility compensation for the subpixel can be accurately performed at the blank time .

FIG. 14 is a diagram illustrating a process of performing single-line sensing and multi-line sensing for each color of sub-pixels according to an embodiment of the present invention. 8 and 9 are applied. 14, one super pixel constitutes R / W / G / B, a sub pixel indicated by a solid line is a sub pixel to which a data voltage is applied, and a sub pixel indicated by a dotted line is a sub pixel to which a data voltage is not applied. When a data voltage is applied to only one subpixel in a superpixel, it indicates that it is a single line sensing. When a data voltage is applied to two or more subpixels, it indicates multi-line sensing.

In FIG. 14, the sub-pixels R representing red in one super pixel perform single-line sensing and the sub-pixels W, G, and B perform multi-line sensing in which the sub-pixel R is an offset sub-pixel. First, as in 1410, driving and sensing for mobility compensation are performed on the sub-pixel Rs. And drives and senses sub-pixels R for each gate line. The sensing voltages outputted from each sub-pixel R are applied to SL [0] to SL [p-1], and the mobility compensation for the sub-pixels R is performed. A signal for sensing driving may be sequentially applied to gate lines of the entire panel or a signal for sensing driving may be applied to gate lines corresponding to a predetermined sequence.

When the sensing and mobility compensation for the subpixels R is completed, multi-line sensing is performed on the subpixels W that exhibit white as in 1420. [ That is, a predetermined data voltage is applied to the subpixel R and the subpixel W within the same super pixel to drive and sense them. Since the mobility / threshold voltage compensation is completed for the sub-pixel R as described above with reference to 1410, the sub-pixel R and the sub-pixel R [p-1] The magnitude of the output sensing voltage is known. Accordingly, the compensating unit 330 determines that the voltage excluding the sensing voltage contributed by the sub-pixel R, which is the offset sub-pixel, is the sensing voltage output from the sub-pixel W at the sensing voltage sensed by the sensing unit 310, And also proceeds to compensate for the mobility. Similarly, the sensing for subpixel G and subpixel B can be applied as in 1430 and 1440.

14, 1420, 1430 and 1440 show an embodiment in which the mobility of the subpixel R is compensated and operates as an offset subpixel. 14, the driving and sensing processes for each sub-pixel are summarized as R driving → R sensing → W / R driving → W sensing → G / R driving → G sensing → B / R driving → B sensing.

Since all the sub-pixels R are compensated for mobility, the sensing lines applied to the sensing line through R can be controlled to be the same. This can be done by applying the data voltage and mobility compensation to it. In another embodiment, the mobility of the offset subpixel is compensated so that the timing controller or compensator can precompute the sensing voltage output by the offset subpixel, so that the offset sensing voltage contributed by the offset subpixel is excluded from the sensing voltage applied to the sensing line And the mobility compensation can be performed by measuring the sensing voltage contributed by the sub-pixel to be actually sensed.

The timing controller can determine whether to drive with offset subpixels or multi-line sensing according to the color of the specific subpixels constituting the superpixel.

For example, R / W / G / B subpixels are included in one superpixel, and R subpixels are selected as offset subpixels, and W / G / B is compensated for multi- .

On the other hand, according to another embodiment, multi-line sensing and single-line sensing can be alternately applied according to the time schedule as well as the color of the sub-pixel. This will be described in more detail in Fig.

For example, when a red subpixel is used as a current source, the red subpixel is an offset subpixel, and the red subpixel is an offset subpixel, The other W, G, and B may be target subpixels to which the actual sensing voltage is to be measured, such as 1420, 1430, and 1440, respectively. Since the size of the driving transistor may be different for each color, a subpixel having a large driving transistor size is set as the current source, and other subpixels are sensed to increase the sensing accuracy even within the output voltage range of the data driver IC. .

FIG. 15 is a flowchart illustrating a mobility sensing process performed during a blank time according to an exemplary embodiment of the present invention. Referring to FIG.

1510 is a section for performing mobility sensing and compensation in the multi-line sensing method during the blank time. A section 1511 for performing a single line sensing on an R subpixel and a section 1512 for performing multi-line sensing on an R / W subpixel. 1520 is a section for sensing and compensating mobility by single line sensing during blank time.

1510 selects two subpixels (R, W) and uses the R as an offset subpixel to perform the mobility sensing, so that the magnitude of the data voltage applied is shorter than that of the period 1520 and the sensing speed is increased. On the other hand, in the process of moving sensing at 1510, accuracy may be lower than that of sensing only one subpixel, so that it is possible to increase accuracy by sensing one subpixel again in a period 1520. [

The selection of the 1510 section and the 1520 section may vary according to the embodiment. The interval 1510 and the interval 1520 may be alternately set according to a predetermined schedule. For example, it is possible to repeat 1510 intervals K times and then 1520 intervals L times.

In another embodiment, when the change in the mobility compensated value in the W subpixel in the section 1520 is less than a predetermined value, the change in mobility is not large, so that multi-line sensing can be performed as in the interval 1510. That is, when the mobility of the subpixel is sensed as a result of sensing the subpixel in the interval 1520, the mobility can be controlled to operate in the 1510 interval for fast sensing and compensation since the mobility is not greatly changed when the difference is small.

On the other hand, when the mobility of the sensing result for the W subpixels is large in the R / W multi-line sensing process in the interval 1510, single line sensing can be performed in 1520 intervals for more accurate sensing.

In the present invention, multi-line sensing or single-line sensing can be selected in one blank time in consideration of the length of the blank time and the time required to sense the sub-pixels. If the sensing time is reduced by using the offset subpixel in one blank time, the blank time can be reduced by that much, so that the image quality can be improved. In addition, since the time required for the mobility sensing is reduced, the mobility compensation period for each subpixel is reduced, and the mobility compensation can be more precise and the image quality can be improved.

16 is a graph showing a relationship between a current and a voltage in a sensing process according to an embodiment of the present invention.

1610, the current flow in the transistor is proportional to the square of the difference between the mobility u and the electrical and physical characteristics of the transistor (Cox, W, L) and the applied voltage. Vg is a voltage applied to the gate terminal of the transistor, and Vs is a voltage applied to the source terminal. Vg is a value obtained by adding Vdata and a compensation value Vth of mobility or threshold voltage. Therefore, the current Isen is the number obtained by multiplying the square of the voltage (Vdata) applied for sensing by a constant constant K, as indicated by 1620 in the sensing process. Since the sensed current Isen is proportional to the sensing voltage Vsen, it can be seen that the sensing voltage Vsen is proportional to the square of Vdata as in 1630.

Here, as described in the present invention, a sensing voltage Vsen_offset applied to a subpixel serving as an offset of two subpixels can be calculated in advance. This is because since the mobility / threshold voltage is compensated for the subpixel, the value can be known. On the other hand, the total voltage Vsen_total sensed in the sensing line is the sum of the sensing voltage Vsen_offset provided by the subpixel serving as an offset and the sensing voltage Vsen_main provided by the subpixel to be actually sensed, Accordingly, the square root of the value obtained by subtracting the offset sensing voltage Vsen_offset from the total sensed value Vsen_total, such as 1640, is proportional to Vdata. Through this, it is possible to compensate the mobility of one subpixel by applying the data voltage to the two subpixels and using the sensed voltage.

17 is a diagram illustrating a process of applying and sensing a signal and a data voltage for multi-sensing by a data driver and a gate driver in an OLED display according to an exemplary embodiment of the present invention.

The gate driver applies a signal for sensing to one gate line (S1710). The data driver applies the first data voltage to the first sub-pixel connected to the gate line and the first sub-pixel connected to the one sensing line, and applies the second data voltage to the second sub-pixel connected to the sensing line in operation S1720. As shown in FIG. 9, a data voltage is applied to two or more subpixels connected to one sensing line. In the first subpixel serving as an offset, the compensation of the mobility / threshold voltage is completed and a data voltage of a size capable of functioning as an offset is applied. For example, when only the first sub-pixel is directly sensed, only a part of the applied data voltage may be applied, and the sensing voltage output from the first sub-pixel may be controlled to be equal to or smaller than a certain size (for example, 1/4 or 1/5) have.

Next, the data driver senses the first sensing voltage at the sensing line (S1730). Since two or more subpixels are connected to the sensing line, the sum of the sensing voltages output through the driving transistors of these subpixels, for example, Vsen_total shown in FIG. 16, is applied to the sensing line, It can be sensed at a sensing voltage. As a result of sensing, the mobility of the second subpixel is compensated using the first sensing voltage (S1740).

17, S1720 to S1740 may be performed simultaneously for each of the sensing lines. Therefore, when there are a total of K sensing lines, sensing is performed simultaneously on K superpixels, which is a set of subpixels sharing one sensing line. At this time, in order to sense one subpixel of each superpixel, A data voltage may be applied to one or more of the offset subpixels of the pixel and the corresponding subpixel. As a result, it is possible to increase the accuracy of mobility compensation by outputting the data voltage for sensing within the range of the voltage that the data driver can output. Particularly, for a sub-pixel having a small size of a driving transistor, a sensing voltage can be added to an offset sub-pixel connected to the same sensing line, thereby improving the sensing accuracy while reducing sensing time.

At this time, the data driver may calculate the first compensation value by performing at least one of mobility compensation for the first subpixel or threshold voltage compensation before sensing the second subpixel to actually compensate the mobility . This allows the first data voltage to be applied to the first subpixel to reflect the first compensation value so that the portion of the entire sensed voltage contributed by the first subpixel can be accurately calculated so that the voltage sensed at the second subpixel And the mobility of the second subpixel can be compensated for by using this. That is, in order to accurately reflect the contribution of the subpixels serving as offsets in the sensing voltage calculated in two or more subpixels and thereby increase the sensing accuracy of the second subpixel to be actually sensed, Or threshold voltage compensation can be completed.

The data driver can be applied to the mobility compensation of the second subpixel using the difference between the first sensed first sensing voltage and the reference voltage to be referred to during sensing, which is the contribution of the total sensing voltage contributed by the offset subpixel It is possible to grasp the degree of occupation of the specific subpixel at the sensing voltage. The method of applying the difference value may be proportional or inversely proportional to the magnitude of the sensing voltage output from the offset subpixel, the magnitude of the data voltage applied to the second subpixel, or the like.

The first sensing voltage sensed by the data driver in the sensing line is the sum of the offset sensing voltage transmitted by the first sub pixel to the sensing line and the second sensing voltage transmitted to the sensing line by the second sub pixel. Since the data driver can calculate the offset sensing voltage, the second sensing voltage can be confirmed, and the mobility of the second subpixel can be compensated using the second sensing voltage.

One embodiment of the present invention provides a technique for sensing the mobility of other subpixels by using a driving transistor of an offset subpixel connected to the same sensing line as a current source. For this purpose, two or more subpixels within one superpixel can be simultaneously sensed.

Here, the offset subpixel except for one subpixel to compensate for the mobility by the actual sensing may all serve as an offset to raise the sensing value to a certain level by all the subpixels in the panel. For the subpixel serving as an offset, the voltage can be inputted by completing mobility compensation on Vdata.

As the display device is implemented with high resolution, the pixel size is reduced and the driving TFT of the OLED has a smaller size in order to secure the aperture ratio. Further, there is a problem that the data voltage for sensing is increased because the sensing operation is performed in a short time in the mobility of the driving TFT. The present invention can be applied to simultaneously sense two or more subpixels in one superpixel to lower the data voltage. The sensed value is a voltage formed by two or more subpixels, but among them, one or more subpixels other than a subpixel to be actually sensed are driven to act as offsets, so that the voltage sensed in the sensing line is a characteristic of one subpixel As a result, the mobility of the corresponding subpixel can be calculated.

Since the magnitude of the data voltage Vdata can be reduced in the sensing process for mobility compensation, accurate mobility compensation is ensured within the range of the output voltage of the source driver IC in the data driver, so that image quality can be maintained. That is, the Vdata can be reduced and the accurate movement can be sensed and compensated.

When the present invention is applied, the Vdata value can be applied so that the voltage to be sensed within a short time of the blank time can be within the proper ADC range. Particularly, in a high-resolution display panel, the size of the driving transistor is reduced and the current capability is reduced. Even in such a reduction of the current capability, the offset sensing is performed so as to sense a specific subpixel using one or more offset subpixels without increasing Vdata. Voltage, thereby increasing the accuracy of mobility compensation and reducing sensing time.

Further, in realizing a high-resolution or large-sized display panel, the capacitance of the sensing line may increase, which may lead to an increase in the Vdata value. However, since the Vdata is not increased by applying the present invention, The mobility compensation of the transistor can be performed accurately.

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 inventions. , Separation, substitution, and alteration of the invention will be apparent to those skilled in the art. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: organic light emitting display
110: Display panel
120: Data driver
130: gate driver
140: Timing controller
310: sensing unit
320: Memory
330:

Claims (18)

A display panel having a plurality of super pixels including at least two sub-pixels including an organic light emitting diode and a driving transistor for driving the organic light emitting diode;
A gate driver coupled to the display panel for applying a signal to the gate line;
A display panel coupled to the display panel for applying a first data voltage to a first subpixel of the superpixel and a second data voltage to a second subpixel of the superpixel, A data driver for sensing a first sensing voltage in a line; And
And a timing controller for controlling the data driver and the gate driver.
The method according to claim 1,
Wherein the data driver or the timing controller compensates the characteristic value of the second subpixel using the first sensing voltage.
The method according to claim 1,
Before the data driver applies the first data voltage to the first subpixel
The data driver or the timing controller completes characteristic value compensation for the first subpixel to calculate a first compensation value,
Wherein the data driver applies the first data voltage to which the first compensation value is reflected to the first sub-pixel.
The method according to claim 1,
Wherein the data driver or the timing controller applies the difference between the first sensing voltage and the reference voltage to compensation of a characteristic value of the second subpixel.
The method according to claim 1,
Wherein the first sensing voltage is a sum of an offset sensing voltage that the first sub-pixel transmits to the sensing line and a second sensing voltage that the second sub-pixel transmits to the sensing line.
The method according to claim 1,
Wherein the first sub-pixel is a first color and the second sub-pixel is a second color.
The method according to claim 1,
And the driving transistor of the second sub-pixel is smaller than the driving transistor of the first sub-pixel.
A display panel having a plurality of super pixels including at least two sub-pixels including an organic light emitting diode and a driving transistor for driving the organic light emitting diode;
A sensing line arranged in K in the first direction on the display panel and M * K arranged data lines;
N gate lines arranged in the second direction on the display panel;
A gate driver for applying a signal for sensing to the gate line;
Applying K first data voltages compensated to each of K first subpixels connected to K first data lines of the data lines, connected to the gate line to which the signal is applied, A data driver for applying K second data voltages to each of the K second subpixels connected to the second data line and sensing a first sensing voltage for each of the second subpixels in the K sensing lines; And
And a timing controller for controlling the gate line and the data driver.
9. The method of claim 8,
Wherein the data driver or the timing controller compensates the characteristic value of the second subpixel using the first sensing voltage.
9. The method of claim 8,
Before the data driver applies the first data voltage to the first subpixel
The data driver or the timing controller completes characteristic value compensation for the first subpixel to calculate a first compensation value,
Wherein the data driver applies K first data voltages having the first compensation value reflected on the K first data lines for each of the first subpixels.
9. The method of claim 8,
Wherein the data driver or the timing controller calculates the difference between the K first sensing voltages sensed at the K sensing lines and the reference voltage and applies the calculated difference to characteristic values of the K second sub pixels.
9. The method of claim 8,
Wherein the first sensing voltage is a sum of an offset sensing voltage that the first sub-pixel transmits to the sensing line and a second sensing voltage that the second sub-pixel transmits to the sensing line.
9. The method of claim 8,
Wherein the K first subpixels are a first color, and the K second subpixels are a second color.
9. The method of claim 8,
And the driving transistor of the second sub-pixel is smaller than the driving transistor of the first sub-pixel.
The gate driver applying a signal for sensing to one gate line;
The data driver applying a first data voltage to a first sub pixel coupled to the gate line and coupled to one sensing line and applying a second data voltage to a second sub pixel connected to the sensing line;
Sensing the first sensing voltage at the sensing line; And
And the data driver or the timing controller compensates the characteristic value of the second subpixel using the first sensing voltage.
16. The method of claim 15,
Before the data driver applies the first data voltage to the first subpixel
Wherein the data driver or the timing controller completes characteristic value compensation for the first subpixel to calculate a first compensation value,
Wherein the first data voltage reflects the first compensation value.
16. The method of claim 15,
The step of compensating for the characteristic value
Wherein the data driver or the timing controller applies a difference between the first sensing voltage and a reference voltage to compensate a characteristic value of the second subpixel.
16. The method of claim 15,
Wherein the first sensing voltage is a sum of an offset sensing voltage that the first sub-pixel transmits to the sensing line and a second sensing voltage that the second sub-pixel transmits to the sensing line.

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