KR20170064162A - Source driver ic, organic light emitting display device, and the method for driving the organic light emitting display device - Google Patents

Abstract

The present invention relates to a source driver integrated circuit, an organic light emitting display and a driving method thereof, and more particularly to a circuit structure capable of sensing an actual output voltage of an amplifier of a source driver integrated circuit together, By calculating the characteristic value of the subpixel using the sensing result of the actual output voltage of the amplifier of the driver integrated circuit, it is possible to accurately calculate the characteristic value of the subpixel from which the offset component of the amplifier of the source driver integrated circuit is removed, And a source driver integrated circuit, an organic light emitting display, and a driving method thereof that can accurately compensate for the characteristic values of subpixels.

Description

TECHNICAL FIELD [0001] The present invention relates to a source driver integrated circuit, an organic light emitting diode (OLED) display device, and a method of driving the same. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present embodiments relate to a source driver integrated circuit, an organic light emitting display, and a driving method thereof.

2. Description of the Related Art In recent years, an organic light emitting diode (OLED) display device that has been popular as a display device has advantages of high response speed, high luminous efficiency, high brightness, and wide viewing angle by using an organic light emitting diode (OLED)

The organic light emitting display includes an organic light emitting display panel in which a plurality of subpixels defined by a plurality of data lines and a plurality of gate lines are disposed and organic light emitting diodes and transistors are disposed in each subpixel, A source driver integrated circuit to be driven, a gate driver integrated circuit to drive a plurality of gate lines, and the like.

On the other hand, the source driver integrated circuit has an amplifier for outputting a data voltage, which amplifier can spontaneously have an offset as a voltage output characteristic.

When the amplifier of the source driver integrated circuit has an offset, if the data is driven by the data voltage outputted from the amplifier, the image may not be driven properly.

When an offset occurs in the sensing driving data voltage output from the amplifier of the source driver integrated circuit for the sensing driving of the subpixel characteristic value such as the threshold voltage and mobility of the transistor, Lt; / RTI > This may lead to a screen anomaly.

It is an object of the present embodiments to provide a source driver integrated circuit, an organic light emitting display, and a driving method thereof that can compensate an offset of an amplifier of a source driver integrated circuit.

It is another object of the present invention to provide a source driver integrated circuit, an organic light emitting diode display, and a driving method thereof that enable sensing of an offset characteristic of an amplifier by sensing an actual output voltage of an amplifier together during a sensing driving process for a characteristic value of a subpixel .

It is still another object of the present embodiments to provide a source driver integrated circuit capable of accurately calculating a characteristic value of a subpixel from which an offset component of an amplifier of a source driver integrated circuit is removed, A display device and a driving method thereof.

In one aspect, the present embodiments relate to an organic light emitting diode, a driving transistor for driving the organic light emitting diode, a sensing transistor electrically connected between the first node of the driving transistor and the sensing line, And a storage capacitor electrically connected between the first node and the second node of the driving transistor, and an organic light emitting diode (OLED) display panel in which subpixels are arranged, A sub-pixel characteristic value calculating unit for calculating a characteristic value of the sub-pixel based on the digital value output from the analog-to-digital converter; A sensing line, A sensing initialization switch electrically connected between the nodes, a first sampling switch electrically coupled between the sensing line and the analog digital converter, and a second sampling switch electrically coupled between the amplifier or data line and the analog digital converter. A display device can be provided.

According to another aspect of the present invention, there is provided an organic light emitting display comprising: an organic light emitting diode; a driving transistor for driving the organic light emitting diode; a sensing transistor electrically connected between the first node of the driving transistor and the sensing line; And a storage capacitor electrically connected between the first node and the second node of the driving transistor, the organic light emitting display panel comprising: can do.

The driving method of the organic light emitting display includes a first step of outputting a data voltage for sensing driving to a data line and outputting a reference voltage to a sensing line, A second step of sensing the output voltage of the amplifier and converting the sensed output voltage into an output voltage sensing value and outputting the sensed output voltage while the analog digital converter is outputting, A fourth step of, when a predetermined time elapses after the supply of the reference voltage is interrupted, the analog digital converter sensing the voltage of the sensing line, converting the sensed sensing line voltage into a sensing line voltage sensing value, A fifth step of calculating a characteristic value of the subpixel based on the output voltage sensing value and the sensing line voltage sensing value .

According to another aspect of the present invention, the embodiments of the present invention are directed to a video signal processing apparatus, comprising D amplifiers corresponding to D data channels electrically connected to D (D? 1) data lines, image data corresponding to D data channels, D digital analog converters for outputting to D amplifiers, an analog digital converter corresponding to S sensing channels electrically connected to S (S? 1) sensing lines, and a sensing channel and a reference voltage supply A first sampling switch for switching the connection between the sensing channel and the analog digital converter for each of the S sensing channels, and a second sampling switch for switching the connection between the output terminal of the amplifier and the analog digital converter A source driver integrated circuit including a second sampling switch for switching the source driver integrated circuit .

According to the embodiments described above, it is possible to provide a source driver integrated circuit, an organic light emitting display, and a driving method thereof that can compensate an offset of an amplifier of a source driver integrated circuit.

In addition, according to the embodiments, a source driver integrated circuit capable of sensing an offset characteristic of an amplifier by sensing an actual output voltage of an amplifier together during a sensing driving process for a characteristic value of a subpixel, an organic light emitting display device, and a driving method thereof Can be provided.

According to the present embodiments, a source driver integrated circuit that accurately calculates a characteristic value of a subpixel from which an offset component of an amplifier of a source driver integrated circuit is removed, thereby correcting the characteristic value of the subpixel, A display device and a driving method thereof can be provided.

1 is a system configuration diagram of an organic light emitting display according to the present embodiments.
FIG. 2 is a view illustrating a sub-pixel structure of an OLED display according to an embodiment of the present invention. Referring to FIG.
3 is an exemplary view of another sub-pixel structure and a compensation circuit of the organic light emitting diode display according to the present embodiments.
4 is a view for explaining a threshold voltage sensing method of a driving transistor of the organic light emitting display according to the present embodiments.
5 is an exemplary view of a sensing line arrangement in an organic light emitting display panel according to the present embodiments.
6 is a diagram schematically showing a source driver integrated circuit of the organic light emitting display according to the present embodiments.
7 is a diagram schematically showing a driving part and a sensing part in a source driver integrated circuit of an organic light emitting display according to the present embodiments.
8 is a diagram for explaining an offset between an offset in an amplifier in the source driver integrated circuit and an offset in an organic light emitting diode display according to the present embodiments.
9 and 10 are diagrams for explaining a threshold voltage sensing error of a driving transistor and a screen abnormal phenomenon when the amplifier in the source driver integrated circuit has an offset in the organic light emitting display according to the present embodiments .
11 is a circuit diagram for compensating for amplifier offset in the OLED display according to the present embodiments.
12 is a timing diagram for threshold voltage sensing of a driving transistor that enables amplifier offset compensation in an organic light emitting display according to the present embodiments.
FIG. 13 is a diagram for explaining an algorithm for calculating a threshold voltage through threshold voltage sensing driving of a driving transistor that enables amplifier offset compensation in an organic light emitting display according to the present embodiments. Referring to FIG.
FIG. 14 is a flowchart illustrating a method of driving an OLED display according to an embodiment of the present invention.
15 is a diagram showing a source driver integrated circuit according to the present embodiments.

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.

The present embodiments disclose a sensing driving method that enables offset compensation of an amplifier in a source driver integrated circuit (SDIC) and a characteristic value calculating algorithm of a subpixel so as to be offset compensated.

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

1, the OLED display 100 includes a plurality of data lines DL and a plurality of gate lines GL, a plurality of sub pixels (SP) A data driver 120 for driving the plurality of data lines DL; a gate driver 130 for driving the plurality of gate lines GL; a data driver 120 And a controller 140 for controlling the gate driver 130 and the like.

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

The controller 140 may be a timing controller used in a conventional display technology or a control device including a timing controller to perform other control functions.

The data driver 120 drives the plurality of data lines DL by supplying data voltages to the plurality of data lines DL. Here, the data driver 120 is also referred to as a 'source driver'.

The data driver 120 may include one or more source driver integrated circuits (SDICs) to drive a plurality of data lines.

The gate driver 130 sequentially supplies the scan signals to the plurality of gate lines GL to sequentially drive the plurality of gate lines GL. Here, the gate driver 130 is also referred to as a " scan driver ".

The gate driver 130 may include at least one gate driver integrated circuit (GDIC).

The gate driver 130 sequentially supplies a scan signal of an On voltage or an Off voltage to the plurality of gate lines GL under the control of the controller 140.

When a specific gate line is opened by the gate driver 130, the data driver 120 converts the image data received from the controller 140 into an analog data voltage and supplies the data voltage to a plurality of data lines DL.

1, the data driver 120 is located only on one side (e.g., on the upper side or the lower side) of the organic light emitting display panel 110, : Upper side and lower side).

1, the gate driver 130 is located only on one side (e.g., the left side or the right side) of the organic light emitting display panel 110. However, the gate driver 130 may be disposed on both sides of the organic light emitting display panel 110 For example, left and right).

The controller 140 described above is capable of outputting various kinds of signals including the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the input data enable signal (DE), and the clock signal (CLK) Timing signals from the outside (e.g., the host system).

The controller 140 receives a timing signal such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, an input DE signal, and a clock signal to control the data driver 120 and the gate driver 130, And generates various control signals and outputs them to the data driver 120 and the gate driver 130.

For example, in order to control the gate driver 130, the 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.

In order to control the data driver 120, the controller 140 may further include a source start pulse (SSP), a source sampling clock (SSC), a source output enable signal (SOE) And outputs various data control signals (DCS: Data Control Signals).

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

Each source driver integrated circuit (SDIC) included in the data driver 120 is connected to the organic light emitting display panel 110 in a Tape Automated Bonding (TAB) or Chip On Glass (COG) The organic light emitting display panel 110 may be connected to a bonding pad of the organic light emitting display panel 110 or may be directly disposed on the organic light emitting display panel 110 and may be integrated and disposed on the organic light emitting display panel 110 as occasion demands. In addition, each source driver integrated circuit (SDIC) may be implemented by a chip on film (COF) method, which is mounted on a film connected to the organic light emitting display panel 110.

Each source driver integrated circuit (SDIC) may include a shift register, a latch circuit, a digital to analog converter (DAC), an output buffer, and the like.

Each source driver integrated circuit (SDIC) may further include an analog to digital converter (ADC), as the case may be.

Each gate driver integrated circuit GDIC included in the gate driver 130 is connected to a bonding pad of the organic light emitting display panel 110 by a tape automated bonding (TAB) method or a chip on glass (COG) Or may be implemented in a GIP (Gate In Panel) type and directly disposed on the organic light emitting display panel 110, or may be integrated on the organic light emitting display panel 110 according to circumstances. In addition, each gate driver IC (GDIC) may be implemented by a chip on film (COF) method, which is mounted on a film connected to the organic light emitting display panel 110.

Each gate driver IC (GDIC) may include a shift register, a level shifter, and the like.

The OLED display 100 according to the present embodiments includes at least one source printed circuit board (S-PCB) necessary for circuit connection to at least one source driver IC (SDIC) And a control printed circuit board (C-PCB) for mounting control components and various electric devices.

At least one source driver integrated circuit (SDIC) may be mounted on at least one source printed circuit board (S-PCB), or a film on which at least one source driver integrated circuit (SDIC) is mounted may be connected.

The control printed circuit board (C-PCB) is provided with a controller 140 for controlling the operation of the data driver 120 and the gate driver 130 and the like, and a controller 140 for controlling operations of the organic light emitting display panel 110, the data driver 120, A power controller for controlling various voltages or currents to supply or supply various voltages or currents to the battery 130, or the like.

The at least one source printed circuit board (S-PCB) and the control printed circuit board (C-PCB) may be circuitly connected via at least one connecting member.

Here, the connecting member may be a flexible printed circuit (FPC), a flexible flat cable (FFC), or the like.

At least one source printed circuit board (S-PCB) and a control printed circuit board (C-PCB) may be integrated into one printed circuit board.

Each sub-pixel SP disposed in the organic light emitting display panel 110 may include a circuit element such as a transistor.

For example, each sub-pixel SP includes circuit elements such as an organic light emitting diode (OLED) and a driving transistor for driving the organic light emitting diode (OLED).

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.

2 is an exemplary view of a sub-pixel structure of the OLED display 100 according to the present embodiments.

Referring to FIG. 2, in the OLED display 100 according to the present embodiment, each sub-pixel basically includes an organic light emitting diode (OLED) and an organic light emitting diode (OLED) A switching transistor SWT for transmitting a data voltage to a second node N2 corresponding to a gate node of the driving transistor DRT; And a storage capacitor (Cstg) for maintaining a data voltage or a voltage corresponding to the data voltage for one frame time.

The organic light emitting diode OLED may include a first electrode (e.g., an anode electrode), an organic layer, and a second electrode (e.g., a cathode electrode).

The driving transistor DRT drives the organic light emitting diode OLED by supplying a driving current to the organic light emitting diode OLED.

The first node N1 of the driving transistor DRT may be electrically connected to the first electrode of the organic light emitting diode OLED and may be a source node or a drain node. The second node N2 of the driving transistor DRT may be electrically connected to the source node or the drain node of the switching transistor SWT and may be a gate node. The third node N3 of the driving transistor DRT may be electrically connected to a driving voltage line DVL for supplying a driving voltage EVDD and may be a drain node or a source node.

The driving transistor DRT and the switching transistor SWT may be implemented as an n-type or a p-type as illustrated in FIG.

The switching transistor SWT is electrically connected between the data line DL and the second node N2 of the driving transistor DRT and can be controlled by receiving the scan signal SCAN through the gate line to the gate node .

The switching transistor SWT may be turned on by the scan signal SCAN to transfer the data voltage Vdata supplied from the data line DL to the second node N2 of the driving transistor DRT.

The storage capacitor Cstg may be electrically connected between the first node N1 and the second node N2 of the driving transistor DRT.

The storage capacitor Cstg is not a parasitic capacitor (e.g., Cgs or Cgd) which is an internal capacitor existing between the first node N1 and the second node N2 of the driving transistor DRT, And is an external capacitor intentionally designed outside the driving transistor DRT.

In the OLED display 100 according to the present embodiment, as the driving time of each sub-pixel SP becomes longer, the driving voltage of the organic light emitting diode OLED, the driving transistor DRT, Degradation can proceed.

Accordingly, inherent characteristic values (e.g., threshold voltage, mobility, etc.) of the circuit elements such as the organic light emitting diode OLED and the driving transistor DRT can be changed.

Such a change in the characteristic value of the circuit element causes the luminance change of the corresponding subpixel. Therefore, the change in the characteristic value of the circuit element can be used in the same concept as the change in luminance of the subpixel.

In addition, the degree of change in the characteristic value between the circuit elements may be different depending on the degree of deterioration of each circuit element.

Such a characteristic value deviation between the circuit elements causes a luminance deviation between the subpixels. Therefore, the characteristic value deviation between the circuit elements can be used in the same concept as the luminance deviation between the subpixels.

The above-described subpixel luminance variation and subpixel luminance variation may cause problems such as degradation of the accuracy with respect to the luminance expression power of the subpixels or occurrence of screen abnormal phenomenon.

Here, the characteristic value of a circuit element (hereinafter also referred to as a " subpixel characteristic value ") may include, for example, a threshold voltage and a mobility of a driving transistor DRT, May include the threshold voltage of the transistor.

The OLED display 100 according to the present embodiment has a sensing function for sensing a sub-pixel luminance change and a sub-pixel luminance deviation (a characteristic value change of a circuit element and a characteristic value deviation between circuit elements) The compensation function for compensating the sub-pixel luminance variation and the sub-pixel luminance deviation can be provided.

The organic light emitting diode display 100 according to the present embodiment includes a subpixel structure and a sensing and compensation structure corresponding thereto to provide a sensing and compensating function for a subpixel luminance change and a luminance deviation between subpixels Compensation circuit.

3 is an exemplary view of another sub-pixel structure and a compensation circuit of the OLED display 100 according to the present embodiments.

Referring to FIG. 3, each sub-pixel disposed in the organic light emitting display panel 110 according to the present exemplary embodiment includes an organic light emitting diode OLED, a driving transistor DRT, a switching transistor SWT, In addition to the capacitor Cstg, it may further include a sensing transistor (SENT).

3, the sensing transistor SENT is electrically connected between a first node N1 of the driving transistor DRT and a sensing line SL that supplies a reference voltage Vref And may be controlled by receiving a sensing signal SENSE as a kind of a scan signal to the gate node.

The sensing transistor SENT is turned on by the sensing signal SENSE and applies the reference voltage Vref supplied through the sensing line SL to the first node N1 of the driving transistor DRT.

Also, the sensing transistor SENT may be utilized as one of the voltage sensing paths for the first node N1 of the driving transistor DRT.

Meanwhile, the scan signal SCAN and the sense signal SENSE may be separate gate signals. In this case, 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 gate signal. In this case, the scan signal SCAN and the sense signal SENSE may be commonly applied to the gate node of the switching transistor SWT and the gate node of the sensing transistor SENT through the same gate line.

Referring to FIG. 3, the organic light emitting display 100 according to the present embodiment senses a deviation between a sub-pixel characteristic value (a characteristic value of the driving transistor, a characteristic of the organic light emitting diode) and / A memory 320 for storing sensing data, a compensation unit for compensating a variation between subpixel characteristic values and / or subpixel characteristic values using sensing data, 330), and the like.

The sensing unit 310 may include at least one analog-to-digital converter (ADC).

Each analog-to-digital converter (ADC) may be included inside the source driver integrated circuit (SDIC) and, in some cases, may be included outside the source driver integrated circuit (SDIC).

The compensation unit 330 may be included inside the controller 140 and, in some cases, may be included outside the controller 140.

The sensing data output from the sensing unit 310 may be, for example, a Low Voltage Differential Signaling (LVDS) data format.

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 sensing initialization switch (SPRE) and a first sampling switch (SAM1) in order to control a state required for sensing.

It can be controlled that the reference voltage Vref is supplied from the reference voltage supply node Nref to the sensing line SL through the sensing initialization switch SPRE.

When the sensing initialization switch SPRE is turned on, the reference voltage Vref is applied to the first node N1 of the driving transistor DRT through the sensing transistor SENT, which is supplied to the sensing line SL and turned on. ). ≪ / RTI >

On the other hand, when the voltage of the first node N1 of the driving transistor DRT becomes a voltage state reflecting the sub-pixel characteristic value, the sensing line SL (which may be of the same potential as the first node N1 of the driving transistor DRT) May also be a voltage state reflecting the sub-pixel characteristic value. At this time, a voltage reflecting a sub-pixel characteristic value may be charged in a line capacitor (not shown) formed on the sensing line SL.

The first sampling switch SAM1 is turned on to turn on the sensing unit 310 and the sensing line SL when the voltage of the first node N1 of the driving transistor DRT becomes a voltage state reflecting the sub- Can be connected.

Accordingly, the sensing unit 310 senses the voltage of the sensing line SL in a voltage state reflecting the sub-pixel characteristic value. Here, the sensing line SL is also referred to as a " reference voltage line ".

Sensing the voltage of the sensing line SL means that sensing the voltage charged in the line capacitor on the sensing line SL and sensing the voltage of the first node N1 of the driving transistor DRT It has meaning.

The voltage sensed by the sensing unit 310 may be either a voltage value Vdata-Vth or Vdata-? Vth including a threshold voltage Vth or a threshold voltage deviation? Vth of the driving transistor DRT, May be a voltage value for sensing the degree of mobility.

Hereinafter, the threshold voltage sensing driving method of the driving transistor DRT will be described with reference to FIG.

4 is a diagram for explaining a threshold voltage sensing driving method for the driving transistor DRT of the OLED display 100 according to the present embodiments.

The first node N1 and the second node N2 of the driving transistor DRT are respectively driven by the reference voltage Vref and the threshold voltage sensing driving data voltage Vdata during the threshold voltage sensing operation of the driving transistor DRT. .

Thereafter, the sensing initialization switch SPRE is turned off to float the first node N1 of the driving transistor DRT.

As a result, the voltage of the first node N1 of the driving transistor DRT rises.

The voltage of the first node N1 of the driving transistor DRT rises and then the rising width gradually decreases and becomes saturated.

The saturated voltage of the first node N1 of the driving transistor DRT may correspond to the difference between the data voltage Vdata and the threshold voltage Vth or the difference between the data voltage Vdata and the threshold voltage deviation Vth .

The sensing unit 310 senses the saturated voltage of the first node N1 of the driving transistor DRT when the voltage of the first node N1 of the driving transistor DRT is saturated.

The voltage Vsen sensed by the sensing unit 310 is a voltage Vdata-Vth obtained by subtracting the threshold voltage Vth from the data voltage Vdata or a voltage Vdata-Vth obtained by subtracting the threshold voltage deviation Vth from the data voltage Vdata Vdata -? Vth).

In accordance with the threshold voltage sensing operation described above, the sensing unit 310 converts the sensed voltage Vsen into a digital value to calculate a threshold voltage, and outputs a sensing value corresponding to the converted digital value (also referred to as a " sensing line voltage sensing value " And outputs the generated sensing data.

The sensing data output from the sensing unit 310 may be stored in the memory 320 or may be provided to the compensating unit 330.

The compensation unit 330 detects the threshold voltage or the threshold voltage change of the driving transistor DRT in the corresponding subpixel based on the sensing data stored in the memory 320 or provided by the sensing unit 310 and performs a threshold voltage compensation process can do.

Here, the threshold voltage change of the driving transistor DRT means that the current sensing data is changed based on the previous sensing data, or the current sensing data is changed based on the reference sensing data.

Here, when comparing the threshold voltage or the threshold voltage change between the driving transistors DRT, the threshold voltage deviation between the driving transistors DRT can be grasped. When the change in the threshold voltage of the driving transistor DRT means that the current sensing data is changed with reference to the reference sensing data, the threshold voltage deviation between the driving transistors DRT from the threshold voltage change of the driving transistor DRT Luminance deviation) can be grasped.

The threshold voltage compensation process is performed by calculating a compensation value for compensating for a threshold voltage or a threshold voltage deviation (threshold voltage variation), storing the calculated compensation value in the memory 320, or using the corresponding video data Data ). ≪ / RTI >

The compensation unit 330 may change the image data Data through the threshold voltage compensation process and supply the changed data to the corresponding source driver integrated circuit (SDIC) in the data driver 120.

Accordingly, the source driver integrated circuit (SDIC) converts the data changed by the compensating unit 330 into the data voltage through the digital-to-analog converter 340 and supplies the data voltage to the corresponding subpixel, thereby realizing the threshold voltage compensation .

As the threshold voltage compensation is performed, luminance deviation between subpixels is reduced or prevented, thereby improving image quality.

5 is an exemplary view of the arrangement of the sensing lines in the organic light emitting display panel 110 according to the present embodiments.

One sensing line SL may be arranged for each sub pixel column, but one sensing line SL may be arranged 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), the sensing lines SL may be arranged one per pixel column .

In accordance with the arrangement of one sensing line SL for every few subpixel rows, among the subpixels contained in the subpixel row, the number of subpixels It is determined whether or not the characteristic values can be sensed together.

For example, when one sensing line SL is disposed for each one subpixel row, the subpixel characteristic values for the subpixels included in the corresponding subpixel row are combined together in one sensing timing interval Can be sensed. That is, one sensing line SL is used to sense sub-pixel characteristics for one sub-pixel.

As another example, when one sensing line SL is arranged for each of two sub pixel rows, the sub pixel characteristic values for half the sub pixels among the sub pixels included in the corresponding sub pixel row are divided into one sensing Can be sensed together in the timing interval. That is, one sensing line SL is shared and used to sense sub-pixel characteristics for two sub-pixels.

As another example, when one sensing line SL is arranged for every three subpixel rows, a subpixel row corresponding to one-third of the subpixels included in the corresponding subpixel row The pixel characteristic values can be sensed together in one sensing timing period. That is, one sensing line SL is shared and used to sense sub-pixel characteristics for two sub-pixels.

5, when one sensing line SL is arranged for each of four sub-pixel rows, a sub-pixel row included in the corresponding sub-pixel row is selected in a specific sensing timing period, The subpixel characteristic values for the subpixels corresponding to one fourth of the pixels may be sensed together in one sensing timing period. That is, one sensing line SL is shared and used to sense sub-pixel characteristics for four sub-pixels.

The characteristic of the sensing line arrangement can be defined as the sensing line share ratio (R). Here, the sensing line sharing ratio R indicates whether one sensing line SL is shared for every few subpixels to sense the subpixel characteristic value.

When one sensing line SL is disposed for each one sub-pixel column, the sensing line share ratio R corresponds to 1/1. When one sensing line SL is arranged for each of two sub-pixel columns, the sensing line share ratio R corresponds to 1/2. When one sensing line SL is arranged for every three sub pixel rows, the sensing line share ratio R corresponds to 1/3. When one sensing line SL is arranged for every four sub-pixel columns, the sensing line share ratio R corresponds to 1/4.

FIG. 5 shows a case where one sensing line SL is arranged for every four sub-pixel lines, and the sensing line share ratio R corresponds to 1/4.

Hereinafter, for convenience of explanation, it is assumed that the sensing line share ratio R is 1/4.

6 is a schematic diagram of a source driver integrated circuit (SDIC) included in the OLED display 100 according to the present embodiments.

Referring to FIG. 6, the source driver integrated circuit (SDIC) may include a Driving Part (DRP) for driving data and a sensing part (SENP) for sensing a subpixel characteristic value.

6, the driving part DRP of the source driver integrated circuit (SDIC) is connected to D data lines (D) through D (D? 1) data channels (DCH # 1, ..., DCH # (DL # 1, ..., DL # D).

6, a sensing part SENP of a source driver integrated circuit (SDIC) is connected to S sensing lines S (S ≥ 1) through sensing channels (SL # 1, ..., SL #S).

In this specification, the voltage of each of the S sensing lines SL # 1, ..., SL #S is the same as the voltage of the first node N1 of the driving transistor DRT in the corresponding subpixel or the first node N1 of the organic light emitting diode OLED May correspond to the voltage of one electrode (e.g., an anode electrode or a cathode electrode).

The voltage of each of the S sensing lines SL # 1 to SL #S is set such that the characteristic value (for example, threshold voltage, mobility, etc.) of the driving transistor DRT in the corresponding sub- And may be a voltage reflecting the characteristic value (e.g., threshold voltage, etc.) of the light emitting diode OLED.

7 is a diagram schematically showing a driving part DRP and a sensing part SENP in a source driver integrated circuit (SDIC) according to the present embodiments.

7, the driving part DRP in the source driver integrated circuit (SDIC) according to the present embodiment includes D latch circuits (LAT # 1, ..., LAT #D) for storing video data, D digital analog converters (DAC # 1, ..., DAC #D) for converting image data into analog voltages, and D amplifiers AMP # 1, ..., DAC # .., AMP #D).

7, D latch circuits LAT # 1 through LAT #D, D digital analog converters DAC # 1 through DAC #D, D amplifiers AMP # 1 ..., AMP #D may correspond to D data channels (DCH # 1, ..., DCH #D) corresponding to D data lines (DL # 1, ..., DL #D).

Referring to FIG. 7, the sensing part SENP in the source driver integrated circuit (SDIC) according to the present embodiment includes S sensing lines (SCH # 1, ..., SCH # A sample and hold circuit (S / H) for storing and holding voltages (sensing line voltages) of the sample and hold circuits SL # 1 to SL # An analog-to-digital converter (ADC) for converting the voltage of each of the S sensing lines SL # 1, ..., and SL # S to a sensing value (sensing line voltage sensing value) .

8 is a graph showing the relationship between the offsets (OS # 1, ..., OS # 2) of the D amplifiers AMP # 1, ..., AMP #D in the source driver integrated circuit (SDIC) in the OLED display 100 according to the present embodiments, OS #D) and the D amplifiers AMP # 1, ..., AMP #D.

Referring to FIG. 8, the D amplifiers AMP # 1, ..., AMP #D in the source driver integrated circuit (SDIC) can have their own offsets (Offset # 1, ..., Offset #D).

Here, the offset is one of the information indicating the voltage output characteristic or the voltage output performance of the amplifier that the amplifier naturally has.

This offset can be defined as the difference between the voltage actually output from the amplifier and the voltage desired to be output.

This offset is also referred to as an offset voltage.

Accordingly, the D amplifiers AMP # 1, ..., AMP #D can not output the data voltage Vdata to be output and the data voltages Vdata and Offset # 1, ..., Offset # The data voltages Vdata + Offset # 1, ..., Vdata + Offset #D added to the data voltages Vdata and Offset #D can be output.

The D amplifiers AMP # 1, ..., AMP #D can not output the data voltage Vdata to be output in accordance with the offsets (Offset # 1, ..., Offset #D) (SDIC) does not provide normal data drive for image driving and sensing driving.

On the other hand, the offset of each of the D amplifiers AMP # 1, ..., AMP #D may be different from each other.

Due to the offset deviation between these D amplifiers AMP # 1, ..., AMP #D, the source driver integrated circuit (SDIC) is more difficult to provide normal data drive for image driving and sensing driving.

9 and 10 are diagrams for explaining the case where the amplifier AMP in the source driver integrated circuit (SDIC) has an offset in the OLED display 100 according to the present embodiment, A sensing error, and a screen abnormal phenomenon.

8, one of the amplifiers AMP of the D amplifiers AMP # 1, ..., AMP #D of the source driver integrated circuit SDIC is connected to the data line through the corresponding channel by the sensing driving data voltage The driving transistor DRT in the corresponding subpixel SP is turned on and off according to the offset of the amplifier AMP when the subpixel SP electrically connected to the corresponding data line is driven by outputting the driving voltage Vdata ' ) Is compared with the result of calculating the threshold voltage (Vth).

Case 1 is an ideal case without an offset of the amplifier (AMP).

In the case of Case 1, the sensing driving data voltage Vdata 'corresponding to the output voltage actually output from the amplifier AMP is the same as the sensing driving data voltage Vdata previously planned for sensing driving.

In the initialization process of the sensing drive, the second node N2 corresponding to the gate node of the driving transistor DRT is supplied with the sensing driving data voltage (the output voltage) corresponding to the output voltage from the amplifier AMP having no offset Vdata ') is applied. A reference voltage Vref is applied to the first node N1 of the driving transistor DRT.

After the initialization of the sensing drive, the first node N1 of the driving transistor DRT is floated and the voltage of the first node N1 of the driving transistor DRT rises.

The voltage of the first node N1 of the driving transistor DRT rises and saturates after a predetermined time elapses.

The saturated voltage of the first node N1 of the driving transistor DRT is substantially equal to the actual voltage of the driving transistor DRT at the sensing data voltage Vdata 'actually applied to the second node N2 of the driving transistor DRT. (Vdata'-Vth = Vdata-Vth, Vdata '= Vdata) minus the threshold voltage Vth.

The sensing unit 310 senses the saturated voltage of the first node N1 of the driving transistor DRT by sensing the voltage of the sensing line SL.

The sensing voltage Vsen of the sensing unit 310 corresponds to a voltage (Vdata'-Vth) obtained by subtracting the actual threshold voltage Vth of the driving transistor DRT from the sensing driving data voltage Vdata '.

In the case of Case 1, the sensing driving data voltage Vdata 'corresponding to the output voltage actually outputted from the amplifier AMP is the same as the sensing driving data voltage Vdata (Vdata' = Vdata ' The sensing voltage Vsen of the sensing unit 310 is a voltage Vdata-Vdata obtained by subtracting the actual threshold voltage Vth of the driving transistor DRT from the data voltage Vdata for sensing driving, Vth).

The compensation unit 330 subtracts the sensing voltage (Vsen = Vdata-Vth) determined from the sensing data provided from the sensing unit 310 from the sensing driving data voltage Vdata previously planned and known for sensing driving The threshold voltage of the transistor DRT can be calculated.

In the case of the ideal Case 1 in which there is no offset of the amplifier AMP, the calculated threshold voltage Vth 'is as shown in Equation 1 below.

In the above equation (1), Vdata is a sensing driving data voltage previously known for sensing driving, Vdata 'is a sensing driving data voltage actually outputted from the amplifier AMP for sensing driving, The sensing voltage sensed by the sensing transistor 310 corresponds to the sensing line voltage, and Vth is the actual threshold voltage of the driving transistor DRT.

According to Equation (1), it can be seen that the calculated threshold voltage Vth 'is equal to the actual threshold voltage Vth.

On the other hand, Case 2 is an actual case with an offset of the amplifier (AMP).

In case 2, the sensing driving data voltage Vdata 'corresponding to the output voltage actually outputted from the amplifier AMP is higher than the sensing voltage Vdata, which is previously planned for sensing driving, (Vdata + Offset) as much as the offset (Offset).

In the initialization process of the sensing drive, the second node N2 corresponding to the gate node of the driving transistor DRT is supplied with the sensing driving data voltage (the output voltage) corresponding to the output voltage from the amplifier AMP having no offset Vdata '= Vdata + Offset) is applied. A reference voltage Vref is applied to the first node N1 of the driving transistor DRT.

After the initialization of the sensing drive, the first node N1 of the driving transistor DRT is floated and the voltage of the first node N1 of the driving transistor DRT rises.

The voltage of the first node N1 of the driving transistor DRT rises and saturates after a predetermined time elapses.

The saturated voltage of the first node N1 of the driving transistor DRT is substantially equal to the actual voltage of the driving transistor DRT at the sensing data voltage Vdata 'actually applied to the second node N2 of the driving transistor DRT. Corresponds to a voltage (Vdata'-Vth) obtained by subtracting the threshold voltage Vth.

The sensing unit 310 senses the saturated voltage of the first node N1 of the driving transistor DRT by sensing the voltage of the sensing line SL.

The sensing voltage Vsen 'of the sensing unit 310 is lower than the actual threshold voltage Vth of the driving transistor DRT from the sensing driving data voltage Vdata' actually applied to the second node N2 of the driving transistor DRT ) (Vdata'-Vth).

In Case 2, the sensing driving data voltage Vdata 'corresponding to the output voltage actually outputted from the amplifier AMP is greater than the sensing voltage Vdata for sensing driving, which is offset from the amplifier AMP Offset (Vdata + Offset). Therefore,

The sensing voltage Vsen 'of the sensing unit 310 is higher than the voltage Vdata of the sensing drive for sensing driving at a voltage Vdata + Offset which is higher than the offset of the amplifier AMP. (Vdata + Offset-Vth) obtained by subtracting the actual threshold voltage (Vth) of the gate electrode (DRT).

However, since the sensing voltage Vsen when there is no offset of the amplifier AMP is Vdata-Vth, the sensing voltage Vsen 'when there is an offset of the amplifier AMP can be expressed as " Vsen + Offset " .

The compensation unit 330 subtracts the actual sensing voltage Vsen 'determined from the sensing data provided from the sensing unit 310 from the sensing driving data voltage Vdata previously planned and known for sensing driving, It is possible to calculate the threshold voltage of the drive signal DRT.

In case of the actual Case 2 in which the offset of the amplifier AMP is present, the calculated threshold voltage Vth 'is as shown in the following equation (2).

In the equation (2), Vdata is a sensing driving data voltage that is previously planned and known for sensing driving, Offset is an offset of the amplifier AMP, and Vsen 'is an offset of the amplifier AMP. Vsen corresponds to the sensing line voltage when there is no offset of the amplifier AMP and Vth is the actual threshold voltage of the driving transistor DRT.

According to Equation (2), it can be seen that the calculated threshold voltage Vth 'differs from the actual threshold voltage Vth by the offset of the amplifier AMP.

That is, the calculated threshold voltage Vth 'is lower than the actual threshold voltage Vth by the offset of the amplifier AMP.

In the case where the amplifier (AMP) in the source driver integrated circuit (SDIC) has an offset, when sensing driving is performed using the voltage output from the amplifier (AMP) having an offset, the actual threshold voltage (Vth) can not be accurately calculated.

This problem is referred to as " threshold voltage sensing error due to offset of amplifier (AMP) ".

8, when an offset deviation occurs between the D amplifiers AMP # 1, ..., AMP #D corresponding to the D data channels DCH # 1, ..., DCH #D, Sensing errors can become worse.

When such a threshold voltage sensing error occurs, a wrong compensation value can be calculated.

As shown in FIG. 10, the compensation value operation error is a phenomenon in which a screen abnormality phenomenon occurs in the image of the vertical strip region 1010 in which the subpixel column in which the image data is driven by the corresponding source driver IC (SDIC #i) Can be generated.

In addition, the D amplifiers AMP # 1, ..., AMP #D in one source driver integrated circuit (SDIC) have offset similar to each other to some extent even if offset deviation exists.

However, a deviation may also occur between the average offsets of the amplifiers of each of the two adjacent source driver integrated circuits (SDIC).

In this case, a compensation value operation error may also be caused by a threshold voltage sensing error. As a result, as shown in Fig. 10, a source driver IC having an average offset deviation from the adjacent source driver IC (SDIC # i + (SDIC # i + 2) may cause a screen abnormal phenomenon to be caused in the image of the vertical block region 1020 where the subpixel columns where the image data is driven are located.

Thus, the embodiments can provide an " amplifier offset compensation " function that reduces or prevents (eliminates) amplifier offset offsets in a source driver integrated circuit (SDIC) or source driver integrated circuit (SDIC) offset variations.

Hereinafter, an amplifier offset compensation method according to the present embodiments will be described in more detail with reference to FIGS. 11 to 15. FIG.

FIG. 11 is a circuit diagram for compensating for amplifier offset in the organic light emitting diode display 100 according to the present embodiment. FIG. 12 is a circuit diagram illustrating an amplifier offset compensation in the OLED display 100 according to the present embodiment. FIG. 13 is a timing diagram for threshold voltage sensing of the driving transistor DRT that enables the driving transistor DRT to be turned on. FIG. 13 is a timing diagram of the driving transistor DRT for enabling amplifier offset compensation in the OLED display 100 according to the present embodiment. FIG. 3 is a diagram for explaining an algorithm for calculating a threshold voltage through threshold voltage sensing driving;

For the convenience of explanation, only the amplifier AMP corresponding to a specific data channel among the D amplifiers AMP # 1, ..., AMP #D in the specific source driver integrated circuit (SDIC) will be described below as an example .

It is also assumed that the gate nodes of the sensing transistor SENT and the switching transistor SWT in the subpixel SP are connected to the same gate line. Accordingly, the sensing signal SENSE applied to the gate node of the sensing transistor SENT and the scanning signal SCAN applied to the gate node of the switching transistor SWT are the same gate signal.

Referring to FIG. 11, the organic light emitting diode display 100 according to the present embodiment includes a circuit for compensating an amplifier offset in a process of driving a sensing for a sub-pixel characteristic value and calculating a sub-pixel characteristic value.

11, this circuit includes an amplifier (AMP) of a source driver integrated circuit (SDIC) that outputs a corresponding data voltage in accordance with image driving or sensing driving or the like, an analog digital converter A sub pixel characteristic value calculating unit 1110 for calculating a characteristic value of the sub pixel SP based on the digital value outputted from the analog digital converter (ADC) and the analog digital converter (ADC), and various switches (SPRE, SAM1, SAM2 ), And the like.

11, each sub-pixel SP includes an organic light emitting diode OLED, a driving transistor DRT for driving the organic light emitting diode OLED, a first node N1 of the driving transistor DRT, A switching transistor SWT electrically connected between the second node N2 of the driving transistor DRT and the data line DL and a driving transistor SWT electrically connected between the driving transistor DRT and the sensing line SL, And a storage capacitor Cstg electrically connected between the first node N1 and the second node N2 of the data driver DRT.

The source driver integrated circuit SDIC is connected to the corresponding data line DL through the amplifier AMP corresponding to the data channel to output a predetermined sensing data voltage Vdata for sensing driving And outputs the data voltage.

It is assumed that the amplifier (AMP) has an offset.

Accordingly, the output voltage actually outputted from the amplifier AMP of the source driver integrated circuit SDIC is not sensed drive data voltage Vdata which is predetermined and desired to be output, (Vdata '= Vdata + Offset).

In the organic light emitting diode display 100 according to the present embodiment, the circuit for compensating the amplifier offset in the process of sensing driving the sub pixel characteristic values and calculating the sub pixel characteristic values through the sensing line SL, A first sampling switch SAM1 electrically connected between the sensing line SL and the analogue digital converter ADC and a second sampling switch SAM2 electrically connected between the sensing line SL and the reference voltage supply node Nref, AMP) or a second sampling switch (SAM2) electrically connected between the corresponding data line (DL) and the analog-to-digital converter (ADC).

By connecting the voltage output terminal of the amplifier AMP of the source driver integrated circuit (SDIC) or the data line DL to the analog-to-digital converter (ADC) using the second sampling switch (SAM2) ADC) can sense the output voltage of the amplifier AMP of the source driver integrated circuit (SDIC).

According to this, when the second sampling switch (SAM2) is turned on, the voltage sensed by the analog-to-digital converter (ADC) corresponds to the output voltage actually output from the amplifier (AMP) of the source driver IC , And the offset of the amplifier (AMP).

Therefore, when the second sampling switch SAM2 is turned on, the voltage (Vdata '= Vdata + Offset) sensed by the analog digital converter (ADC) and the source driver IC (SDIC) The offset (offset) of the amplifier AMP can be found from the difference of the voltage Vdata desired to be outputted.

A second sampling switch SAM2 for connecting the voltage output terminal of the amplifier AMP of the source driver integrated circuit (SDIC) or the data line DL to the analog-to-digital converter ADC, as shown in Fig. 11, , The offset is reflected in the amplifier AMP to sense the output voltage actually outputted, thereby detecting the offset of the amplifier AMP or allowing the offset compensation to be performed.

11 and 12, the second sampling switch SAM2 is turned on during the periods S10 to S30 during which the sensing driving data voltage Vdata 'is outputted from the amplifier AMP of the source driver integrated circuit (SDIC) Can be turned on.

Accordingly, the analog-to-digital converter (ADC) can sense the sensing driving data voltage (Vdata '), which is reflected by the offset in the amplifier (AMP) and actually outputted for the sensing driving for the subpixel characteristic value.

11 to 13, the second sampling switch SAM2 may be turned on during a period S10 during which the sensing initialization switch SPRE is turned on.

This makes it possible to initialize the first node N1 and the second node N2 of the driving transistor DRT at the time of driving the sensing of the subpixel characteristic value without providing a separate time for sensing the output voltage of the amplifier AMP , It is possible to sense the sensing driving data voltage Vdata 'which is reflected by the offset in the amplifier AMP and is actually outputted. Thus, the driving time and the driving procedure can be simplified.

11 to 13, the sensing initialization switch SPRE is turned on for a predetermined sensing initialization time during a period S10 to S30 during which the sensing driving data voltage Vdata 'is output from the amplifier AMP And the first sampling switch SAM1 is turned on after a predetermined time elapses after the sensing initialization switch SPRE is turned off.

Accordingly, in order to drive the threshold voltage sensing, the voltage of the first node N1 of the driving transistor DRT rises and saturates (S20), and the voltage of the first node N1 of the driving transistor DRT (S30) may be performed.

11 to 13, in step S10, the sensing initialization switch SPRE is turned on so that the first node N1 of the driving transistor DRT is initialized to the reference voltage Vref.

The sensing initialization switch SPRE is turned off in step S20 so that the first node N1 of the driving transistor DRT is floated and the voltage of the first node N1 of the driving transistor DRT rises .

While the sensing initialization switch SPRE is turned off in step S20, the voltage of the first node N1 of the driving transistor DRT rises and saturates after a predetermined time elapses.

When the voltage of the first node N1 of the driving transistor DRT becomes saturated, the first sampling switch SAM1 is turned on at the beginning of the step S30.

When the first sampling switch SAM1 is turned on, the analog-to-digital converter ADC is electrically connected to the sensing line SL to sense the voltage of the sensing line SL.

The sensing line voltage Vsen 'obtained by sensing the voltage of the sensing line SL by the analog / digital converter ADC is substantially equal to the actual threshold voltage Vth from the sensing driving data voltage Vdata' actually output from the amplifier AMP. (Vdata'-Vth).

The sensing driving data voltage Vdata 'actually output from the amplifier AMP is a voltage (Vdata + Offset) obtained by adding an offset to the previously-planned sensing driving data voltage Vdata.

When the amplifier AMP has no offset, the sensing line voltage Vsen sensed by the analog-digital converter ADC on the sensing line SL is preliminarily set to a predetermined voltage (Vdata - Vth) obtained by subtracting the actual threshold voltage (Vth) from the data voltage (Vdata).

Considering that the sensing line voltage Vsen 'obtained by sensing the voltage of the sensing line SL by the analog / digital converter ADC is Vdata = Vdata + Offset and Vsen = Vdata-Vth, Corresponds to a voltage (Vsen + Offset) obtained by adding the offset of the sensing line voltage Vsen and the offset of the amplifier AMP to which the analog digital converter ADC senses the voltage of the sensing line SL .

11 to 13, when the analog digital converter ADC is electrically connected to the voltage output terminal of the amplifier AMP or the data line DL according to the turn-on of the second sampling switch SAM2, The output voltage Vdata 'of the amplifier AMP is sensed, and the sensed output voltage Vdata' is converted into an amplifier output voltage sensing value corresponding to a digital value and transmitted to the subpixel characteristic value calculation unit 1100.

Accordingly, the subpixel characteristic value calculating unit 1100 can find the offset of the amplifier AMP based on the received amplifier output voltage sensing value (digital value for Vdata ').

For example, the subpixel characteristic value calculating unit 1100 subtracts the digital value for the previously-planned sensing driving data voltage (Vdata) from the received amplifier output voltage sensing value (digital value for Vdata '), A digital value for offset (offset voltage) can be obtained.

11 to 13, when the analog digital converter ADC is electrically connected to the sensing line SL according to the turn-on of the first sampling switch SAM1, the voltage of the sensing line SL is sensed And converts the sensed sensing line voltage Vsen 'into a sensing line sensing value corresponding to a digital value, and transmits the sensing line sensing value to the subpixel characteristic value calculation unit 1100.

Here, as described above, the sensing line voltage Vsen 'sensed by the analog-to-digital converter (ADC) is determined by the voltage of the sensing line SL when the amplifier AMP is not offset, (Vsen + Offset) obtained by adding the sensed sensing line voltage (Vsen) and the offset of the amplifier (AMP).

The subpixel characteristic value calculating unit 1100 calculates the subpixel characteristic value based on the amplifier output voltage sensing value received from the analog digital converter (ADC) in step S10 and the sensing line sensing value received from the analog digital converter (ADC) SP) can be calculated.

For example, the subpixel characteristic value calculating unit 1100 may calculate the threshold voltage of the driving transistor DRT as a characteristic value of the subpixel SP by subtracting the amplifier output voltage sensing value and the sensing line sensing value .

The calculated threshold voltage Vth 'can be expressed by the following equation (3).

In the equation (3), Vth 'is the calculated threshold voltage, Vdata' is the sensing driving data voltage actually output from the corresponding amplifier (AMP) of the corresponding source driver integrated circuit (SDIC) Vdata is a sensing driving data voltage that is previously planned and known for sensing driving, Offset is an offset of the offset of the amplifier AMP, Vsen is the sensing line voltage when there is no offset of the amplifier AMP, and Vth is the actual threshold voltage of the driving transistor DRT.

According to Equation (3), it can be seen that the threshold voltage Vth 'equal to the actual threshold voltage Vth can be calculated even though the amplifier AMP has an offset.

As shown in Equation 3, the characteristic value calculated by the subpixel characteristic value calculating unit 1100 is a value obtained by subtracting the offset deviation between the amplifier AMP and the other amplifier AMP in the same source driver integrated circuit (SDIC) Characteristic value, or the offset deviation of the amplifiers of the source driver integrated circuit (SDIC) and the source driver integrated circuit (SDIC) of the other source driver integrated circuit (SDIC) may be removed.

As described above, the sensing driving data voltage (Vdata ') actually sensed by the corresponding amplifier (AMP) of the corresponding source driver integrated circuit (SDIC) is sensed during the sensing operation for the subpixel characteristic value, For example, the threshold voltage of the driving transistor DRT), it is possible to obtain the sub-pixel characteristic value that has been subjected to amplifier offset compensation. Accordingly, it is possible to calculate an accurate compensation value that does not reflect the amplifier offset, thereby preventing a screen abnormal phenomenon as shown in FIG.

Hereinafter, a driving method for compensating for the offset of the amplifier will be briefly described again with reference to Fig.

FIG. 14 is a flowchart of a method of driving the organic light emitting diode display 100 according to the present embodiments.

Referring to FIG. 14, the driving method of the OLED display 100 according to the exemplary embodiments of the present invention outputs a sensing driving data voltage Vdata 'on a data line DL, While the sensing driving data voltage Vdata 'is being output from the amplifier AMP of the source driver IC (SDIC) to the data line DL in the first step S1410 of outputting the voltage Vref, A second step S1430 of sensing the output voltage Vdata 'of the amplifier AMP and converting the sensed output voltage Vdata' to an output voltage sensing value and outputting the sensed output voltage Vdata ' A third step S1450 of shutting off the output of the reference voltage Vref to the sensing line SL after the supply of the reference voltage Vref is cut off, ), And the sensed sensing line voltage (Vsen ') is sensed as a sensing line voltage sensing value On the basis of a second step 4 (S1460) the ring output, the output voltage value and sensing the sensing the line voltage sensing value, and may include a fifth step (S1470) for calculating a characteristic value such as a sub-pixel (SP).

The characteristic value calculated in step S1470 may be a characteristic value from which the offset deviation of the amplifier AMP is removed.

According to the driving method described above, the sensing driving data voltage Vdata ', which is actually output from the amplifier AMP in the sensing driving process for the subpixel characteristic value and in which the offset is reflected, is sensed, By using the sensing driving data voltage Vdata 'sensed in a state where an offset is reflected when the subpixel characteristic value is calculated on the basis of the sensing line voltage sensed through the sensing line voltage AMP, the offset of the amplifier AMP is removed The subpixel characteristic value of the state can be calculated. Accordingly, it is possible to prevent a compensation error arising from an offset of the amplifier AMP and to prevent a screen abnormal phenomenon as shown in FIG.

That is, when the actual output voltage of the amplifier AMP is sensed together in the sensing driving process for the subpixel characteristic value, and the subpixel characteristic value is calculated through the sensing operation for the subpixel characteristic value, the actual output voltage of the amplifier AMP By calculating the subpixel characteristic value using the sensing result, the subpixel characteristic value in which the offset of the amplifier AMP is naturally removed can be obtained.

Meanwhile, the second step S1430 may be performed together with the first step S1410.

This makes it possible to initialize the first node N1 and the second node N2 of the driving transistor DRT at the time of driving the sensing of the subpixel characteristic value without providing a separate time for sensing the output voltage of the amplifier AMP , It is possible to sense the sensing driving data voltage Vdata 'which is reflected by the offset in the amplifier AMP and is actually output in step S1410. Thus, the driving time and the driving procedure can be simplified.

Meanwhile, before the second step S1430, while the amplifier AMP is outputting the sensing driving data voltage Vdata 'to the data line DL, the output terminal of the amplifier AMP is connected to the analog- (Step S1420) may be further performed.

After the second step S1430, a step S1440 of releasing the connection between the output stage of the amplifier AMP and the analog-digital converter ADC may be further performed.

According to this, the output voltage of the amplifier AMP can be sensed without affecting the existing sensing drive of the subpixel characteristic value. Thus, an efficient sensing drive that enables amplifier offset compensation can be made possible.

On the other hand, a source driver integrated circuit (SDIC) for efficient sensing driving that enables amplifier offset compensation will be described with reference to FIG.

15 is a diagram showing a source driver integrated circuit (SDIC) according to the present embodiments.

15, a source driver IC (SDIC) according to the present embodiment includes D data lines DL # through D (D 1) through a data channel (DCH # 1, ..., DCH #D) 1, ..., DL #D) and are electrically connected to S sensing lines SL # 1, ..., SL # S via S (S? 1) ).

The source driver IC SDIC according to the present embodiment includes D latch circuits LAT # 1 to LAT #D, D digital analog converters DAC # 1 to DAC #D, and D Amplifiers AMP # 1, ..., AMP #D, and the like.

The source driver integrated circuit (SDIC) according to the present embodiments further includes a sample and hold circuit (S / H) and an analog-to-digital converter (ADC).

The D amplifiers AMP # 1 to AMP #D are connected to D data channels DCH # 1 to DCH #D electrically connected to D data lines DL # 1 to DL # .

The D digital analog converters DAC # 1 to DAC #D convert the image data corresponding to the D data channels DCH # 1 to DCH #D into analog voltages and output the D amplifiers AMP # 1, ..., AMP #D).

The analog-to-digital converter (ADC) corresponds to S sensing channels (SCH # 1, ..., SCH #S) electrically connected to the S sensing lines SL # 1, ..., SL #S.

In addition, the source driver integrated circuit (SDIC) according to the present embodiments may further include various switches, capacitors, and the like.

Referring to FIG. 15, the source driver IC (SDIC) according to the present embodiment includes a plurality of source driver ICs (SDICs) for each of S sensing channels (SCH # 1, ..., SCH # , And a sensing initialization switch (SPRE # 1, ..., SPRE #S) for switching the connection.

In addition, the source driver IC (SDIC) according to the present embodiment is provided with a sensing channel and an analog-digital converter (ADC) for each of the S sensing channels (SCH # 1, ..., SCH # 1,..., SAM1 # S) for switching the connection between the first sampling switches (SAM1 # 1, ..., SAM1 #S).

In addition, the source driver IC (SDIC) according to the present embodiment controls the output stage of the amplifier and the analog-to-digital converter (ADC) for each of the D amplifiers AMP # 1, ..., AMP # And second sampling switches SAM2 # 1, ..., SAM2 #D for switching connections between the first and second sampling switches.

The use of the above-described source driver integrated circuit (SDIC) enables sensing driving on the subpixel characteristic value, sensing driving operation in which the offset is reflected in the actual output in the amplifier (AMP) So that the data voltage Vdata 'can be sensed.

Accordingly, when the subpixel characteristic value calculating unit 1100 calculates the subpixel characteristic value based on the sensing line voltage sensed through the sensing driving of the characteristic value, the sensing driving data voltage Vdata ' , It is possible to calculate the subpixel characteristic value in a state where the offset of the amplifier AMP is removed. Accordingly, it is possible to prevent a compensation error arising from an offset of the amplifier AMP and to prevent a screen abnormal phenomenon as shown in FIG.

The second sampling switches SAM2 # 1 to SAM2 #D may be included in the source driver IC (SDIC) as shown in FIG. 15, and in some cases, May be implemented as transistors in the non-active region of the source driver integrated circuit 110 and may be mounted on a printed circuit board or a source printed circuit board on which the source driver integrated circuit (SDIC) may be mounted.

Accordingly, the second sampling switches SAM2 # 1, ..., SAM2 #D that allow the output voltages of the D amplifiers AMP # 1, ..., AMP #D to be sensed are supplied to the organic light emitting display 100 ) Of the present invention.

According to the embodiments as described above, the source driver IC (SDIC), the organic light emitting diode display 100, and the driving circuit thereof, which can compensate the offset of the amplifier AMP of the source driver integrated circuit Method can be provided.

According to the embodiments of the present invention, a source driver IC (SDIC) that detects the offset characteristic of the amplifier (AMP) by sensing the actual output voltage of the amplifier together during the sensing driving process for the characteristic value of the subpixel, The display apparatus 100 and the driving method thereof can be provided.

In addition, according to the present embodiments, it is possible to accurately calculate the characteristic value of the subpixel from which the offset component of the amplifier AMP of the source driver integrated circuit (SDIC) has been removed, and to accurately compensate the characteristic value of the subpixel. A driver integrated circuit (SDIC), an organic light emitting display device 100, and a driving method thereof.

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: organic light emitting display panel
120: Data driver
130: gate driver
140: controller

Claims (15)

A driving transistor for driving the organic light emitting diode; a sensing transistor electrically connected between a first node of the driving transistor and a sensing line; and a driving transistor electrically connected between the second node of the driving transistor and the data line, An organic light emitting display panel in which subpixels are disposed, the organic light emitting display panel comprising a switching transistor and a storage capacitor electrically connected between a first node and a second node of the driving transistor;
A source driver integrated circuit for outputting a data voltage to the data line through an amplifier corresponding to the data line;
An analog digital converter for converting an analog voltage into a digital value and outputting the digital value;
A sub pixel characteristic value calculation unit for calculating a characteristic value of the sub pixel based on the digital value output from the analog digital converter;
A sensing initialization switch electrically coupled between the sensing line and a reference voltage supply node;
A first sampling switch electrically connected between the sensing line and the analog digital converter; And
And a second sampling switch electrically connected between the amplifier or the data line and the analog digital converter. The method according to claim 1,
Wherein the second sampling switch comprises:
Wherein the data driver is turned on during a period in which the sensing driving data voltage is output from the amplifier. The method according to claim 1,
Wherein the second sampling switch comprises:
Wherein the sensing initialization switch is turned on during a period during which the sensing initialization switch is turned on. The method according to claim 1,
The sensing initialization switch comprises:
The sensing voltage is turned on and off during a predetermined sensing initialization time in a period during which the data voltage for sensing driving is outputted from the amplifier,
Wherein the first sampling switch comprises:
Wherein the sensing initialization switch is turned on after a predetermined time elapses after the sensing initialization switch is turned off. 5. The method of claim 4,
After the sensing initialization switch is turned off,
Wherein the voltage of the sensing line rises while saturating. The method according to claim 1,
The analog-to-
When the amplifier is electrically connected to the amplifier or the data line according to the turn-on of the second sampling switch,
Sensing the output voltage of the amplifier, and converting the sensed output voltage to an output voltage sensing value corresponding to a digital value and transmitting the sensed output voltage value to the subpixel characteristic value calculation unit. The method according to claim 6,
The analog-to-
When the first sampling switch is electrically connected to the sensing line according to the turn-on of the first sampling switch,
Sensing the voltage of the sensing line, converting the sensed sensing line voltage into a sensing line sensing value corresponding to a digital value, and transmitting the sensing line sensing value to the subpixel characteristic value calculating unit,
The subpixel characteristic value calculating unit may calculate,
And the characteristic value of the subpixel is calculated based on the output voltage sensing value and the sensing line sensing value. 8. The method of claim 7,
The subpixel characteristic value calculating unit may calculate,
And the threshold voltage of the driving transistor is calculated as a characteristic value of the subpixel by subtracting the sensing voltage value from the sensing voltage value. 9. The method of claim 8,
Wherein the characteristic value calculated by the subpixel characteristic value calculating unit
A characteristic value in which an offset deviation between the amplifier and another amplifier in the source driver integrated circuit is removed,
Wherein an offset deviation of each of the amplifiers of the source driver integrated circuit and the source driver integrated circuit is removed. The method according to claim 1,
Wherein the second sampling switch comprises:
Wherein the source driver integrated circuit is included in the source driver integrated circuit or is located in a non-active region of the organic light emitting display panel or mounted on a printed circuit board. A driving transistor for driving the organic light emitting diode; a sensing transistor electrically connected between a first node of the driving transistor and a sensing line; and a driving transistor electrically connected between the second node of the driving transistor and the data line, And a storage capacitor electrically connected between the first node and the second node of the driving transistor, the organic light emitting display comprising:
A first step of outputting a data voltage for sensing driving to the data line and outputting a reference voltage to the sensing line;
The analog-to-digital converter senses the output voltage of the amplifier and converts the sensed output voltage into an output voltage sensing value while the data voltage for sensing driving is output from the amplifier of the source driver integrated circuit to the data line. Step 2;
A third step of interrupting the output of the reference voltage to the sensing line;
A fourth step of sensing the voltage of the sensing line when the predetermined time elapses after the supply of the reference voltage is cut off, converting the sensing line voltage into a sensing line voltage sensing value, and outputting the sensed line voltage sensing value;
And a fifth step of calculating a characteristic value of the subpixel based on the output voltage sensing value and the sensing line voltage sensing value. 12. The method of claim 11,
The calculated characteristic value is a value
Wherein an offset deviation of the amplifier is removed. 12. The method of claim 11,
Wherein the second step is performed together with the first step. 12. The method of claim 11,
Prior to the second step,
And connecting the output terminal of the amplifier to the analog digital converter while the amplifier is outputting the sensing driving data voltage to the data line,
After the second step,
And disconnecting the connection between the output terminal of the amplifier and the analog-digital converter. D amplifiers corresponding to D data channels electrically connected to D (D? 1) data lines;
D digital-to-analog converters for converting image data corresponding to the D data channels into analog voltages and outputting them to the D amplifiers; And
An analog-to-digital converter corresponding to S sensing channels electrically connected to S (S? 1) sensing lines;
A sensing initialization switch for switching the connection between the sensing channel and the reference voltage supply node for each of the S sensing channels;
A first sampling switch for switching the connection between the sensing channel and the analog digital converter for each of the S sensing channels; And
And a second sampling switch for switching the connection between the output terminal of the amplifier and the analog-digital converter for each of the D amplifiers.

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