KR102543039B1 - Organic Light Emitting Diode Display And Processing Method For Dark Spot Of The Same - Google Patents

Abstract

An organic light emitting display device according to the present invention includes a display panel including a plurality of pixels, each pixel including a first color subpixel, a second color subpixel, a third color subpixel, and a fourth color subpixel; A sensing unit connected to the pixels through sensing lines and configured to sense electrical characteristics of subpixels and output sensed values; a sensing unit analyzing the sensed values to find defective subpixels that are dark spots; An error detector for deriving corresponding error coordinates, determining compensation coordinates for compensating for luminance loss due to the dark spots based on the error coordinates, calculating a luminance share to be compensated for at each of the compensation coordinates, and a luminance calculation unit that up-modulates input image data written to the compensation coordinates by the luminance share.

Description

Organic Light Emitting Diode Display And Processing Method For Dark Spot Of The Same

The present invention relates to an organic light emitting display device and a dark spot treatment method thereof.

An active matrix type organic light emitting display device includes an organic light emitting diode (OLED) that emits light by itself, and has advantages of fast response speed, high luminous efficiency, luminance, and viewing angle.

An OLED, which is a self-luminous device, includes an anode electrode, a cathode electrode, and organic compound layers (HIL, HTL, EML, ETL, EIL) formed therebetween. The organic compound layer includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer, EIL). When a driving voltage is applied to the anode electrode and the cathode electrode, holes that have passed through the hole transport layer (HTL) and electrons that have passed through the electron transport layer (ETL) move to the light emitting layer (EML) to form excitons, and as a result, the light emitting layer (EML) visible light is generated.

An organic light emitting display device arranges subpixels each including an OLED in a matrix form, and adjusts luminance of the subpixels according to gray levels of video data. Each of the sub-pixels includes a driving element that controls a driving current flowing through the OLED according to a voltage applied between its gate electrode and its source electrode, that is, a driving TFT (Thin Film Transistor). Electrical characteristics of the driving TFT, such as threshold voltage and mobility, deteriorate with the lapse of driving time, and thus, deviations may occur for each sub-pixel. If the electrical characteristics of the driving TFT are different for each sub-pixel, even if the same image data is written, the luminance between the sub-pixels is different, and thus the display quality is degraded.

An external compensation technique for compensating for a change in electrical characteristics of the driving TFT by sensing the electrical characteristics of the driving TFT and correcting input image data based on the sensed value is known. The external compensation technology may use a voltage sensing method of sensing a voltage of a specific node connected to a source electrode of the driving TFT or a current sensing method of sensing a pixel current flowing through the driving TFT in order to sense the electrical characteristics of the driving TFT. In the current sensing method, a current integrator is connected to a sensing line, and electrical characteristics of the driving TFT are sensed through a current accumulated in the current integrator for a specific time.

Meanwhile, in order to increase the aperture ratio of the display panel, a plurality of subpixels constituting one pixel may be designed to share the same sensing line. In such a sensing line sharing structure, a defect generated in one sub-pixel within the same pixel affects sensing results for the remaining normal sub-pixels within the same pixel. For example, assuming that a defective sub-pixel A and a normal sub-pixel B in which an OLED short circuit (a short circuit between the anode and cathode electrodes of the OLED) has occurred are included in a pixel sharing the same sensing line, the pixel of the normal sub-pixel B Since a portion of the current leaks into the defective sub-pixel A, it is impossible to accurately sense the normal sub-pixel B. In the pixel including the defective subpixel, the sensing values of the remaining normal subpixels may be distorted from the original values or may underflow or overflow beyond the output range of the sensing unit. Incorrect sensing values are reflected in input image data, resulting in distortion of a displayed image.

In this way, even if a defect occurs in only some subpixels in the sensing line sharing structure, a desired image cannot be realized through pixels including the defective subpixels, and the image is distorted. OLEDs are vulnerable due to changes over time and accumulated loads, and in some cases, short-circuit defects in which the anode electrode and the cathode electrode are short-circuited may occur. If there is a short-circuit defect, the corresponding OLED does not emit light, and the sub-pixel including the defective OLED becomes a dark spot. In some cases, the entire pixel including the defective sub-pixel may be recognized as a dark spot.

Accordingly, an object of the present invention is to provide an organic light emitting display device capable of improving a defect rate by compensating for a luminance loss due to a defective subpixel using neighboring subpixels and a dark spot processing method thereof.

In order to achieve the above object, an organic light emitting display device according to the present invention includes a plurality of pixels, and each pixel is composed of a first color subpixel, a second color subpixel, a third color subpixel, and a fourth color subpixel. The configured display panel, a sensing unit connected to the pixels through a plurality of sensing lines, sensing electrical characteristics of the subpixels and outputting sensed values, and analyzing the sensed values to detect defective subpixels that become dark spots. an error detection unit for finding and deriving error coordinates corresponding to the defective sub-pixels, determining compensation coordinates for compensating for luminance loss due to the dark spots based on the error coordinates, and luminance compensated at each of the compensation coordinates and a luminance calculation unit that up-modulates input image data written to the compensation coordinates by the luminance share after calculating the luminance share.

The luminance calculation unit determines locations of subpixels having the same color as the defective subpixel among pixels adjacent to the defective subpixel, using the compensation coordinates, and determines the defective subpixels from the first color to the first color. At least one of the fourth color subpixels.

The luminance calculator determines positions of subpixels other than the defective subpixel in the pixel including the defective subpixel using the compensation coordinates, and the defective subpixel is the first to fourth color subpixels. It is a white sub-pixel.

The luminance calculation unit may include a position weight generation unit generating position weights according to a distance between each of the compensation coordinates and the error coordinates, and based on the position weights and the luminance according to the input image data to be written to the compensation coordinates. a compensation weight calculation unit that determines compensation weights for calculating the luminance shares for each of the compensation coordinates, and the luminance shares obtained by multiplying the input image data to be written to the error coordinates by the compensation weights A luminance compensation unit is provided to increase the luminance of the compensation coordinates by the luminance share in addition to the input image data to be written in the coordinates.

The compensation weight calculation unit implements a luminance share of the compensation coordinates in addition to the luminance according to the input image data to be written to the compensation coordinates within a preset maximum output luminance including a data margin and a threshold voltage margin. A margin analyzer for analyzing whether a luminance margin is satisfied for each of the compensation coordinates, and a position weight adjustment unit for adjusting the position weight of each of the compensation coordinates based on a result of the luminance margin analysis.

The position weight adjuster reduces the position weight of a first compensation coordinate whose luminance margin is not satisfied among the compensation coordinates to a range where the luminance margin is satisfied, and at least one or more second compensation coordinates in which the luminance margin is satisfied. Compensation is made by sharing the reduced position weight of the compensation coordinates.

The sensing unit performs primary sensing on all pixels according to a first sensing condition and outputs a sensing value corresponding thereto, and secondarily senses some pixels according to a second sensing condition different from the first sensing condition to perform sensing corresponding thereto. A value is output, but the partial pixels are pixels disposed on a horizontal pixel line including the defective sub-pixel.

In the odd-numbered horizontal pixel line and the even-numbered horizontal pixel line of the display panel, the sub-pixel arrangement order of pixels adjacent to each other is different from each other, and the sub-pixels constituting the first pixel in the odd-numbered horizontal pixel line are: Second pixels disposed in the order of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel, and vertically adjacent to the first pixel on the even horizontal pixel line. The subpixels constituting are arranged in the order of the third color subpixel, the fourth color subpixel, the first color subpixel, and the second color subpixel.

In addition, the present invention is a dark spot of an organic light emitting display device having a display panel including a plurality of pixels, each pixel including a first color subpixel, a second color subpixel, a third color subpixel, and a fourth color subpixel. A processing method comprising: sensing electrical characteristics of the subpixels through a sensing unit connected to the pixels through a plurality of sensing lines and outputting sensed values; and analyzing the sensed values to detect defective subpixels as dark spots. finding and deriving error coordinates corresponding to the defective sub-pixels, determining compensation coordinates for compensating for luminance loss due to the dark spots based on the error coordinates, and luminance compensation compensated at each of the compensation coordinates and up-modulating the input image data written in the compensation coordinates by the luminance share after calculating the luminance.

The present invention can dramatically improve the defect rate by compensating for the luminance loss due to the defective sub-pixel using neighboring sub-pixels.

In addition, the present invention can accurately detect the position of a defective sub-pixel within a relatively short time by performing primary sensing and secondary sensing with different sensing conditions.

Furthermore, according to the present invention, not only W dark spots but also R, G, and B dark spots can be corrected, so that an organic light emitting display device with better visibility and reliability can be implemented.

1 is a diagram showing an organic light emitting display device according to an exemplary embodiment of the present invention;
2 and 3 are views showing the configuration of a data driver IC including a pixel array and a sensing unit according to the present invention.
4 and 5 are diagrams showing examples of sensing units connected to sub-pixels according to the present invention.
6 is a diagram showing various devices for scotoma compensation according to the present invention.
7 and 8 are diagrams schematically showing a scotoma compensation procedure according to the present invention.
9 is a diagram showing the configuration of the luminance calculation unit of FIG. 6;
10 is a diagram showing the configuration of a compensation weight calculation unit of FIG. 9;
11A and 11B show one compensation scheme for bad sub-pixels.
12 is a diagram for explaining a luminance share compensated for at each of compensation coordinates determined based on error coordinates;
13 is a diagram showing an example of position weights determined according to distances between compensation coordinates and error coordinates;
14 is a diagram showing an example in which position weights are adjusted according to a luminance margin analysis result according to image data;
15a and 15b show different compensation schemes for bad sub-pixels.
16 is a diagram showing a range of a luminance margin determined according to image data within an output voltage range preset in a data driving circuit;
17 is a diagram showing a pixel arrangement in which sub-pixels of the same color are arranged closest to each other among adjacent pixels;
18 is a diagram showing the principle of individually sensing sub-pixels within a pixel under the sensing line sharing structure according to the present invention;
19 is a diagram showing the path of pixel current when the OLED senses a shorted defective sub-pixel.
20 is a diagram showing sensing results when an OLED senses a short-circuited defective sub-pixel.
21 is a diagram showing a current path when a defective sub-pixel is sensed within a single pixel;
22 is a diagram showing a current path when sensing a normal sub-pixel adjacent to a defective sub-pixel within a single pixel;
23 and 24 are diagrams showing various examples of changing sensing conditions in order to increase discrimination of sensed values according to secondary sensing;

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various forms different from each other, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, so the present invention is not limited to the details shown. Like reference numbers designate like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification is used, other parts may be added unless 'only' is used. In the case where a component is expressed in the singular, the case including the plural is included unless otherwise explicitly stated.

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

In the case of a description of a positional relationship, for example, when the positional relationship of two parts is described as 'on ~', 'upon ~', '~ below', 'next to', etc., 'right' Or, unless 'directly' is used, one or more other parts may be located between the two parts.

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

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

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

1 shows an organic light emitting display device according to an exemplary embodiment of the present invention. 2 and 3 show a configuration of a data driver IC including a pixel array and a sensing unit according to the present invention. 4 and 5 show examples of sensing units connected to the sub-pixels of the present invention.

1 to 5 , an organic light emitting display device according to an exemplary embodiment of the present invention includes a display panel 10, a timing controller 11, a data driving circuit 12, a gate driving circuit 13, and a memory 16. ), and a dark spot compensation circuit 20. The dark spot compensation circuit 20 may be built into the timing controller 11, but is not limited thereto.

A plurality of data lines and sensing lines 14A and 14B and a plurality of gate lines 15 intersect in the display panel 10, and subpixels P are arranged in a matrix form at each crossing area to form a pixel. construct an array

Each subpixel P is connected to one of the data lines 14A, one of the sensing lines 14B, and one of the gate lines 15. The sub-pixels P constituting the pixel array include an R sub-pixel for displaying red, a G sub-pixel for displaying green, a B sub-pixel for displaying blue, and a W sub-pixel for displaying white. do. The R, G, B, and W sub-pixels may constitute one pixel UPXL. However, the configuration of the pixel UPXL is not limited thereto. At least two sub-pixels P constituting one pixel UPXL may share one sensing line 14B. In the following embodiments of the present invention, all sub-pixels P in the same pixel UPXL share one sensing line 14B, but the technical idea of the present invention is not limited thereto. The technical concept of the present invention may be applied even when the sensing line 14B is shared in units of some sub-pixels within the same pixel UPXL. Each of the subpixels P may be driven by receiving a high potential driving voltage EVDD and a low potential driving voltage EVSS from a power generator (not shown).

The pixel P of the present invention may include an OLED, a driving TFT (DT), a storage capacitor (Cst), a first switch TFT (ST1), and a second switch TFT (ST2). The TFTs may be implemented as P-type, N-type, or hybrid types in which P-type and N-type are mixed. In addition, the semiconductor layer of the TFT may include amorphous silicon, polysilicon, oxide, or a combination thereof.

The OLED includes an anode electrode connected to the source node Ns, a cathode electrode connected to an input terminal of the low potential driving voltage EVSS, and an organic compound layer positioned between the anode electrode and the cathode electrode. The organic compound layer includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer, EIL) may be included.

The driving TFT (DT) controls the size of the source-drain current (Ids) of the driving TFT (DT) input to the OLED, that is, the pixel current (Ids), according to the gate-source voltage (hereinafter referred to as Vgs). . The driving TFT (DT) has a gate electrode connected to the gate node Ng, a drain electrode connected to the input terminal of the high potential driving voltage EVDD, and a source electrode connected to the source node Ns. The storage capacitor Cst is connected between the gate node Ng and the source node Ns to maintain Vgs of the driving TFT DT for a certain period of time.

The first switch TFT ST1 switches the electrical connection between the data line 14A and the gate node Ng according to the gate pulse SCAN. The first switch TFT (ST1) has a gate electrode connected to the gate line 15, a drain electrode connected to the data line 14A, and a source electrode connected to the gate node Ng. The second switch TFT ST2 switches an electrical connection between the source node Ns and the sensing line 14B according to the gate pulse SCAN. The second switch TFT (ST2) has a gate electrode connected to the gate line 15, a drain electrode connected to the sensing line 14B, and a source electrode connected to the source node Ns.

Meanwhile, the first switch TFT ( ST1 ) and the second switch TFT ( ST2 ) may be connected to different gate lines 15A and 15B, respectively, as shown in FIG. 5 . In this case, the gate electrode of the first switch TFT (ST1) is connected to the first gate line 15A, and the data line 14A and the gate node ( Ng) can switch the electrical connection between them. Also, the gate electrode of the second switch TFT (ST2) is connected to the second gate line 15B, and the source node Ns and the sensing line 14B are connected according to the gate pulse SEN from the second gate line 15B. ) can switch the electrical connection between them.

The organic light emitting display device of the present invention having such a pixel array employs an external compensation technique to sense the electrical characteristics of the driving TFT (DT) and correct the input image data (DATA) according to the sensed value. Electrical characteristics of the driving TFT include the threshold voltage of the driving TFT and electron mobility of the driving TFT.

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

The gate control signal GDC includes a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable signal (Gate Output Enable (GOE)), and the like. The gate start pulse GSP is applied to the gate stage generating the first scan signal and controls the gate stage to generate the first scan signal. The gate shift clock GSC is a clock signal commonly input to the gate stages and is a clock signal for shifting the gate start pulse GSP. The gate output enable signal GOE is a masking signal that controls outputs of the gate stages.

The data control signal DDC includes a source start pulse (SSP), a source sampling clock (SSC), and a source output enable signal (SOE). The source start pulse SSP controls data sampling start timing of the data driving circuit 12 . The source sampling clock SSC is a clock signal that controls data sampling timing in each of the source drive ICs based on a rising or falling edge. The source output enable signal SOE controls output timing of the data driving circuit 12 .

The timing controller 11 may distinguish between basic driving for writing image data DATA_V′ and sensing driving for acquiring sensing values, and may generate different control signals DDC and GDC in basic driving and sensing driving. there is. The timing controller 11 may further generate switch control signals for operating the switches (SW1 , SW2 , and SW3 of FIG. 4 or SWa and SWb of FIG. 5 ) in the sensing unit SU in the sensing drive.

The timing controller 11 derives a characteristic deviation of the driving TFT (DT) between sub-pixels based on the digital sensing value (SD) obtained according to the sensing drive, and a threshold capable of reducing the characteristic deviation of the driving TFT (DT). A voltage compensation value and a mobility compensation value may be calculated and reflected in the input image data DATA. The timing controller 11 may update and store the calculated threshold voltage compensation value and mobility compensation value in the memory 16 .

The timing controller 11 analyzes the sensed value SD through the built-in dark spot compensating circuit 20 to find a defective sub-pixel that becomes a dark spot, and derives error coordinates corresponding to the defective sub-pixel. Reasons for occurrence of defective sub-pixels that become dark spots may include OLED short-circuit defects as illustrated in FIGS. 18 to 22 and defects due to progressive deterioration of the driving TFT (DT). The OLED short-circuit defect may be particularly problematic in a sensing line sharing structure in which two or more horizontally adjacent subpixels share one sensing line. On the other hand, defects due to progressive deterioration of the driving TFT (DT) may also be a problem in a sensing line independent structure in which horizontally adjacent subpixels are individually connected to sensing lines. The technical idea of the present invention, which will be described below, is not limited to a cause of defects and a sensing line shared/independent structure.

The dark spot compensation circuit 20 determines compensation coordinates for compensating for the luminance loss due to the dark spots based on the error coordinates, calculates the luminance portion to be compensated for at each of the compensation coordinates, and then calculates the luminance portion The input image data DATA written in the compensation coordinates may be up-modulated by as much as

The timing controller 11 may transmit the modulated image data DATA_V' to the data driving circuit 12 during basic driving to compensate for the luminance loss due to the electrical characteristic deviation of the driving TFT and the dark spot.

The data driving circuit 12 includes at least one source driver Integrated Circuit (IC) (SDIC). This source driver IC (SDIC) is a pixel through a latch array (not shown), a plurality of digital-to-analog converters 121 (hereinafter referred to as DACs) connected to each data line 14A, and sensing lines 14B. and a sensing circuit 122 coupled to the array.

The latch array latches the modulated image data DATA_V′ input from the timing controller 11 based on the data control signal DDC and supplies the latches to the DAC. During basic driving, the DAC may convert modulated image data DATA_V′ input from the timing controller 11 into data voltages for image display and supply the converted data voltages to the data lines 14A. When driving, the DAC generates an on-level sensing data voltage (VON in FIG. 18) and supplies it to the data lines 14A, and generates an off-level sensing data voltage (VOFF in FIG. 18) to the data lines. fields 14A. The on-level sensing data voltage is a voltage that allows the pixel current (Ids) to flow through the driving TFT (DT), and the off-level sensing data voltage does not allow the pixel current (Ids) to flow through the driving TFT (DT). It is the voltage that prevents

The sensing circuit 122 includes a plurality of sensing units SU. The sensing units SU may be implemented as a current sensing type as shown in FIG. 4 or as a voltage sensing type as shown in FIG. 5 .

A sensing operation through the sensing unit SU may be performed during a power-on sequence period before the input image data DATA is written in the display panel 10 . The power-on sequence period refers to a period from when the driving power is turned on until the input image data DATA is written.

The current sensing type sensing unit SU of FIG. 4 directly senses the Ids of the driving TFT transmitted through the sensing line 14B, and may include a current integrator CI and a sample & hold unit SH. The current sensing type sensing unit (SU) supplies the initialization voltage (Vpre) to the sensing line (14B) based on the data control signal (DDC), samples the analog sensing value input through the sensing line (14B), and It can be supplied to a digital converter (hereinafter referred to as an ADC). The current integrator (CI) integrates the pixel current (Ids) of the driving TFT input through the sensing line (14B), and the sampling & holding unit (SH) samples and holds the output voltage (Vout) of the current integrator (CI). to generate an analog sensing value. The ADC sequentially digitally processes the outputs of the sampling & holding units (SH) and transmits the digital sensed value (SD) to the timing controller 11 .

Specifically, the current integrator (CI) is connected to the sensing line 14B and receives the pixel current (Ids) of the driving TFT (DT) from the sensing line 14B through an inverting input terminal (-) and an initialization voltage (Vpre). An amplifier (AMP) including a non-inverting input terminal (+) that receives input, an output terminal that outputs a voltage (Vout) according to the accumulation of pixel current (Ids) during the sensing period, and an inverting input terminal (-) of the amplifier (AMP) It includes a feedback capacitor (Cfb) connected between output terminals, and a first switch (SW1) connected to both ends of the feedback capacitor (Cfb) and turned on/off according to the reset control signal (RST). When the first switch SW1 is turned on, the input terminals (+, -) and the output terminal of the current integrator CI are all reset to the initialization voltage Vpre. The current integration operation performed by the current integrator CI is performed when the first switch SW1 is turned off.

The sampling & holding unit (SH) is turned on according to the sampling control signal (SAM) and the second switch (SW2) connecting the output terminal of the current integrator (CI) to the holding capacitor (Ch), according to the holding control signal (HOLD) The third switch (SW3), which is turned on and connects the holding capacitor (Ch) to the input terminal of the ADC, and one end is connected between the second switch (SW2) and the third switch (SW3) and the other end is connected to the base voltage source (GND) and a holding capacitor (Ch) for storing the voltage (Vout) output from the current integrator (CI).

This current sensing type sensing unit (SU) is advantageous in reducing the sensing time relatively because it is capable of low-current and high-speed sensing.

Meanwhile, the voltage sensing type sensing unit SU of FIG. 5 senses the voltage stored in the line capacitor LCa of the sensing line 14B in response to the Ids of the driving TFT DT, and the initialization switch SW1 and sampling A switch (SW2) and a sample and hold unit (S/H) may be provided. The initialization switch SW1 switches an electrical connection between the input terminal of the reference voltage Vref and the sensing line 14B according to the initialization control signal PRE. The sampling switch SW2 switches an electrical connection between the sensing line 14B and the sample and hold unit S/H according to the sampling control signal SAM. When the source node voltage of the driving TFT (DT) changes according to the Ids of the driving TFT (DT), the sample and hold unit (S/H) is connected to the line capacitor ( The source node voltage of the driving TFT (DT) stored in LCa) is sampled and held as an analog sensing value, and then transmitted to the ADC. The ADC sequentially digitally processes the outputs of the sample and hold units (S/H) and transmits digital sensing values (SD) to the timing controller 11.

The gate driving circuit 13 may generate gate pulses for image display based on the gate control signal GDC during basic driving and then sequentially supply them to the gate lines 15 in a row-sequential manner. The gate driving circuit 13 may generate gate pulses for sensing based on the gate control signal GDC during sensing driving and then supply the gate pulses to the gate lines 15 in a row sequential method or a random method. The gate pulse for sensing may have a wider on-pulse interval than the gate pulse for image display. Each of the gate pulses for image display and sensing applied to each sub-pixel may be singular or plural.

6 shows various apparatuses for scotoma compensation according to the present invention. 7 and 8 schematically show the scotoma compensation procedure of the present invention.

Referring to FIG. 6 , the dark spot compensation circuit 20 of the present invention includes a gray-luminance conversion unit 111, a luminance calculation unit 112, an error detection unit 113, a luminance-voltage conversion unit 114, and a voltage calculation unit ( 115) may be included.

The gray-luminance conversion unit 111 converts the input image data DATA from a grayscale domain to a luminance domain using a first lookup table for conversion between gray (grayscale) and luminance.

As shown in FIG. 7 , the error detection unit 113 analyzes the sensed values SD inputted from the sensing units SU of the data driving circuit 12 line by line to find a defective sub-pixel that is a dark spot, and finds the defective sub-pixel. Error coordinates corresponding to pixels are obtained (S11 to S13). The error detector 113 transfers the obtained error coordinates to the luminance calculator 112 (S14). The error detection unit 113 may perform such a series of error coordinate deriving operations up to the last horizontal pixel line according to a line sequential method (S15).

Meanwhile, the sensing units SU firstly sense all pixels according to a first sensing condition and output a sensing value corresponding to the first sensing condition so that the error detection unit 113 can easily derive the error coordinates. Some pixels may be secondarily sensed according to a second sensing condition different from , and a sensing value corresponding thereto may be output. Here, some pixels may be pixels disposed on a horizontal pixel line including the defective sub-pixel. Operations of these sensing units SU will be described later with reference to FIGS. 18 to 24 .

The luminance calculator 112 modulates the image data DATA_L input from the gray-luminance converter 111 to output modulated data DATA_L' in the luminance domain. To this end, the luminance calculator 112 determines compensation coordinates for compensating for luminance loss due to dark spots based on the error coordinates, as shown in FIG. 8 ( S21 ). The luminance calculator 112 determines compensation weights within the luminance domain for calculating luminance shares compensated for at each of the compensation coordinates based on the position weight and the luminance margin (S22). The luminance calculator 112 may compensate for luminance loss due to error coordinates by up-modulating the input image data written in the compensation coordinates in the luminance domain by an amount corresponding to the luminance share (S23 and S24).

There may be two methods for determining compensation coordinates in the luminance calculator 112 . First, when the defective sub-pixel is at least one of the R, W, G, and B sub-pixels, the luminance calculator 112 selects a sub-pixel that implements the same color as the defective sub-pixel in adjacent pixels adjacent to the defective sub-pixel. Positions of s can be determined as compensation coordinates (see FIGS. 11A to 14).

Next, when the defective subpixel is a W subpixel, the luminance calculator 112 may determine positions of subpixels other than the defective subpixel in the pixel including the defective subpixel as compensation coordinates (FIG. 15A). and FIG. 15B).

The luminance-voltage conversion unit 114 converts the modulation data DATA_L' of the luminance domain input from the luminance calculation unit 112 into voltage domain data using a preset second lookup table for conversion between luminance and voltage. In addition, the luminance-voltage converter 114 secures the luminance margin by further considering the data margin of the voltage domain (DATA_V margin in FIG. 16) in addition to the threshold voltage margin (Vth margin in FIG. 16) input from the voltage calculator 115. After that, it is supplied to the luminance calculation unit 112.

The voltage calculator 115 may calculate a threshold voltage margin (Vth margin in FIG. 16 ) based on the threshold voltage compensation value and the mobility compensation value stored in the memory 16 and supply the calculated threshold voltage margin to the luminance-voltage converter 114 . The voltage calculator 115 applies the threshold voltage compensation value and the mobility compensation value to the voltage domain modulated data DATA_V input from the luminance-voltage converter 114 and outputs the final modulated data DATA_V′ of the voltage domain. do. The final modulated data DATA_V' is supplied to the data driving circuit 12.

FIG. 9 shows the configuration of the luminance calculation unit of FIG. 6 . FIG. 10 shows the configuration of the compensation weight calculation unit of FIG. 9 . 11a and 11b show one compensation scheme for bad sub-pixels. 12 is a diagram for explaining a luminance share compensated for at each of compensation coordinates determined based on error coordinates. 13 shows an example of position weights determined according to the distance between each of the compensation coordinates and the error coordinates. 14 shows an example in which position weights are adjusted according to a result of luminance margin analysis according to image data. 15a and 15b show another compensation scheme for bad sub-pixels. 16 shows a range of a luminance margin determined according to image data within an output voltage range preset in a data driving circuit.

9 to 16 , the luminance calculator 112 includes a buffer 121, a position weight generator 122, a compensation weight calculator 123, and a luminance compensator 124.

The buffer unit 121 stores the error coordinates (Xn, Yn) input from the error detection unit 113, and converts the stored error coordinates (Xn, Yn) to the position weight generation unit 122 according to the data enable signal DE. forward to

The position weight generation unit 122 determines compensation coordinates (Xn', Yn') based on the error coordinates (Xn, Yn) input from the buffer unit 121, and determines the compensation coordinates (Xn', Yn'). Position weights (PW) are generated according to the distance between each and the error coordinates (Xn, Yn) and supplied to the compensation weight calculator 123. The compensation coordinates (Xn', Yn') include compensation coordinate 1 (Xn-1, Yn) having a first position weight (PW1) and compensation coordinate 2 (Xn+1, Yn) having a second position weight (PW2). ), compensation coordinates 3 (Xn, Yn+1) having a third position weight (PW3), and compensation coordinates 4 (Xn, Yn-1) having a fourth position weight (PW4). The position weight generation unit 122 increases the position weight PW in proportion to the distance between each of the compensation coordinates Xn' and Yn' and the error coordinates Xn and Yn, thereby increasing the effect of compensating for the luminance loss. . For example, as shown in FIG. 13, the interval between error coordinates (Xn, Yn) and compensation coordinates 1 (Xn-1, Yn) and the interval between error coordinates (Xn, Yn) and compensation coordinates 2 (Xn+1, Yn) are Each is D2, and the interval between error coordinates (Xn, Yn) and compensation coordinates 3 (Xn, Yn+1) and the interval between error coordinates (Xn, Yn) and compensation coordinates 4 (Xn, Yn-1) are D1 (D1), respectively. is less than D2), the position weight generator 122 sets the position weights (PW) given to compensation coordinates 1 (Xn-1, Yn) and compensation coordinates 2 (Xn+1, Yn) to 20%. and the position weight (PW) given to compensation coordinates 3 (Xn, Yn+1) and compensation coordinates 4 (Xn, Yn-1) can be generated at 30%.

The compensation weight calculator 123 receives a luminance margin from the luminance-voltage converter 114 and receives compensation coordinates (Xn', Yn') including the position weight PW from the position weight generator 122. . The compensation weight calculation unit 123 includes the luminance margin, the luminance according to the input image data to be written into the compensation coordinates (Xn', Yn'), the preset maximum luminance, the position weight (PW), and the error coordinates (Xn, Yn'). A compensation weight (MW) for calculating the luminance share for each of the compensation coordinates is determined using luminance according to input image data to be written in Yn).

The luminance compensator 124 multiplies the input image data to be written to the error coordinates (Xn, Yn) by the compensation weight (MW) input from the compensation weight calculator 123, and divides the luminance into the compensation coordinates (Xn'). In addition to the input image data to be written in ,Yn'), the luminance of the compensation coordinates is increased by the luminance share. For example, as shown in FIG. 12 , the luminance compensator 124 converts the luminance of compensation coordinate 1 (Xn-1, Yn) into the first luminance division "DATA_L(Xn,Yn)*PW(Xn-1, Yn)", and the luminance of compensation coordinate 2 (Xn+1,Yn) is increased by "DATA_L(Xn,Yn)*PW(Xn+1,Yn)", which is the second luminance share, and compensation coordinate 3 (Xn ,Yn+1) is increased by "DATA_L(Xn,Yn)*PW(Xn,Yn+1)", which is the third luminance share, and the luminance of compensation coordinate 4 (Xn,Yn-1) is increased to the fourth luminance. It can be increased by "DATA_L (Xn, Yn) * PW (Xn, Yn-1)", which is the share. Here, the sum of the first to fourth luminance shares may be equal to "DATA_L(Xn,Yn)", which is a luminance loss at error coordinates (Xn,Yn), and when an additional weight is applied to improve visibility, the luminance It may be slightly different from the loss "DATA_L(Xn,Yn)".

Meanwhile, the compensation weight calculation unit 123 may include a margin analysis unit 1231 and a position weight adjustment unit 1232 as shown in FIG. 10 in order to adjust the compensation weight MW according to the luminance margin.

The margin analyzer 1231 includes compensation coordinates (in addition to the luminance according to the input image data to be written in the compensation coordinates (Xn', Yn') within a preset maximum output luminance including the data margin and the threshold voltage margin. It is analyzed for each of the compensation coordinates (Xn', Yn') whether or not the luminance margin capable of implementing the luminance share of Xn', Yn' is satisfied.

The position weight adjuster 1232 may adjust the compensation weight MW by adjusting the position weight PW of each of the compensation coordinates Xn' and Yn' based on the luminance margin analysis result.

As shown in FIG. 14, the position weight adjuster 1232 reduces the position weight PW of the first compensation coordinates (Xn, Yn+1) for which the luminance margin is not satisfied among the compensation coordinates to a range where the luminance margin is satisfied (for example, For example, from 30% to 10%), at least one or more second compensation coordinates (Xn+1,Yn) (Xn,Yn-1) for which the luminance margin is satisfied. Compensation by sharing the reduced position weight (20%) (for example, additional 10% sharing at compensation coordinate 2 (Xn+1,Yn), and additional 10% sharing at compensation coordinate 4 (Xn,Yn-1)) can do.

Meanwhile, when the defective sub-pixel is the W sub-pixel PW, the luminance calculator 112 calculates the defective W sub-pixel PW in the pixel UPXL including the defective W sub-pixel PW as shown in FIGS. 15A and 15B in addition to the above method. Positions of the R, G, and B subpixels PR, PG, and PB excluding the subpixel PW may be determined as compensation coordinates. 15B shows luminance distributions for subpixels PR, PG, and PB constituting the same pixel as the white subpixel PW in order to compensate for the luminance loss due to the W subpixel PW, which is a defective subpixel. is shown These luminance shares may be differently controlled for each color in consideration of color coordinates. For example, the luminance divisions may be controlled such that R:G:B=2:7:1 is satisfied, but is not limited thereto. Adjustment ratios of the luminance divisions may vary according to models, specifications, and the like.

17 shows a pixel arrangement in which sub-pixels of the same color are disposed closest to each other among adjacent pixels.

The sub-pixel arrangement of the present invention may be modified as shown in the right side of FIG. 17 so that compensation coordinates adjacent to the error coordinates are arranged at similar intervals. Referring to FIG. 17 , in odd-numbered horizontal pixel lines OHL and even-numbered horizontal pixel lines EHL, the sub-pixel arrangement order of vertically adjacent pixels is different. In other words, the subpixels constituting the first pixel UPXL1 in the odd-numbered horizontal pixel line OHL include the first color subpixel PR, the second color subpixel PW, and the third color subpixel PG. ) and the fourth color sub-pixel PB are arranged in that order. On the other hand, sub-pixels constituting the second pixel UPXL2 vertically adjacent to the first pixel UPXL1 in the even-th horizontal pixel line EHL include a third color sub-pixel PG and a fourth color sub-pixel. (PB), the first color subpixel PR, and the second color subpixel PW are arranged in that order.

If compensation coordinates adjacent to the error coordinates are arranged at similar intervals, it becomes easier to set position weights for the compensation coordinates.

18 to 24 show in detail a sensing process for accurately deriving error coordinates. 18 shows a principle in which sub-pixels within a pixel are individually sensed under the sensing line sharing structure according to the present invention.

As shown in FIG. 18, when each pixel UPXL is composed of R sub-pixels PR, G sub-pixels PG, B sub-pixels PB, and W sub-pixels PW sharing the same sensing line, 1 horizontal A total of four sensing operations are required to sense a pixel line. In the first sensing operation, the on-level sensing data voltage VON is applied only to the R sub-pixels (PR) located on one horizontal pixel line to sense only the R sub-pixels (PR) at the same time, During the second sensing, the on-level sensing data voltage VON is applied only to the G subpixels PG belonging to the first horizontal pixel line to simultaneously sense only the G subpixels PG, and the third sensing At this time, only the B sub-pixels (PB) belonging to the first horizontal pixel line are applied with the on-level sensing data voltage (VON) to simultaneously sense only the B sub-pixels (PB), and during the 4th sensing, the first horizontal The on-level sensing data voltage VON is applied only to the W sub-pixels PW belonging to the pixel line to simultaneously sense only the W sub-pixels PW. Under the sensing line sharing structure, all sub-pixels are sensed according to the above-described sequential sensing method for each color in order to increase sensing accuracy. However, as shown in FIGS. 19 to 22 , when one sub-pixel existing in the same pixel is defective, it is difficult to obtain a desired sensing result even if individual sensing is performed in units of sub-pixels according to the sequential sensing method for each color.

19 shows the path of pixel current when the OLED senses a shorted defective sub-pixel. And, FIG. 20 shows the sensing result in the case where the OLED senses a short-circuited defective sub-pixel.

First, referring to FIGS. 19 and 20 , a principle of obtaining a sensing voltage by the sensing unit SU will be briefly described as follows.

During the initialization period Tint, the first switch SW1 is turned on by the reset control signal RST, and accordingly, the input terminals (+-) and the output terminal of the current integrator CI are reset to the initialization voltage Vpre. do. During the initialization period Tint, the output voltage Vout of the current integrator CI is maintained at the initialization voltage Vpre.

During the sensing period Tsen, the first switch SW1 is turned off and the second switch SW2 is turned on by the sampling control signal SAM, so that the pixel current Ix input from the sub-pixel is converted to the feedback capacitor Cfb. ) is accumulated. Accordingly, a voltage difference proportional to the accumulated current is generated between both ends of the feedback capacitor Cfb (ΔV=(1/C)*∫idt). At this time, since the potential of the inverting input terminal (-) of the current integrator (CI) is fixed to the initialization voltage (Vpre) by the virtual ground, the output voltage of the current integrator (CI) is equal to the voltage difference caused by the accumulated current. (Vout) is lowered from the initialization voltage (Vpre). During the sensing period Tsen, the output voltage Vout of the current integrator CI is stored as a sensing voltage in the holding capacitor Ch.

During the sampling period Tsam, the second switch SW2 is turned off and the third switch SW3 is turned on by the holding control signal HOLD, so that the sensing voltage stored in the holding capacitor Ch is output to the ADC accordingly. .

Thus, in order for all of the pixel current Ix flowing through the driving TFT to be accumulated in the current integrator CI, there must be no current leakage through the OLED. However, as shown in FIG. 19, when sensing a defective sub-pixel in which a short circuit occurs in the OLED, a part of the pixel current (Iy2) leaks into the input terminal of the low-potential driving voltage (EVSS), and the pixel current accumulated in the current integrator (CI). (Iy1) decreases. Therefore, as shown in FIG. 20 , the sensing voltage Vsen2 for the defective subpixel is relatively higher than the sensing voltage Vsen1 for the normal subpixel, and accordingly, the voltage difference between the sensing voltage Vsen2 and the initialization voltage Vpre ( ΔV2) is smaller than the voltage difference ΔV1 between the sensing voltage Vsen1 and the initialization voltage Vpre.

Through the relative size of the voltage difference, the present invention can detect whether a defective sub-pixel is included in a pixel.

21 shows a current path when sensing a defective sub-pixel within a single pixel. 22 shows a current path when sensing a normal subpixel adjacent to a defective subpixel within a single pixel.

As shown in FIGS. 21 and 22 , when there are defective sub-pixels Pa and normal sub-pixels Pb sharing the same sensing line 14B within a single pixel UPXL, the A difference occurs between the first sensing voltage and the second sensing voltage for the normal subpixel Pb.

In the sensing line sharing structure, a defect occurring in one sub-pixel within the same pixel affects sensing results for the remaining normal sub-pixels within the same pixel. This is because, as shown in FIG. 22 , some of the pixel current Ib2 of the normal subpixel Pb leaks to the defective subpixel Pa via the sensing line 14B.

Specifically, the leakage current Ib2 when sensing the normal subpixel Pb as shown in FIG. 22 is smaller than the leakage current Ia2 when sensing the defective subpixel Pa as shown in FIG. 21 . This is because the leakage current Ib2 has to pass through two more switch TFTs ST2 compared to the leakage current Ia2, and the resistance affected by that amount is large. For this reason, the second sensing voltage Vsen2 for the defective subpixel Pa is relatively higher than the first sensing voltage Vsen1 for the normal subpixel Pb.

A difference in sensing voltage between a normal sub-pixel and a defective sub-pixel within the same pixel is not substantially large. In order to accurately detect a defective sub-pixel within the same pixel, it is necessary to change sensing conditions.

23 and 24 show various examples of changing sensing conditions in order to increase a difference between a sensing value between a defective subpixel and a normal subpixel within the same pixel.

The sensing unit SU of the present invention firstly senses all pixels according to a first sensing condition, outputs a corresponding sensed value, and secondarily senses some pixels according to a second sensing condition different from the first sensing condition. It outputs the sensed value corresponding to it. Here, some pixels refer to pixels disposed on a horizontal pixel line including defective sub-pixels.

The error detection unit stores the positions of bad pixels based on the sensing values obtained through the primary sensing of all pixels, and accurately locates the defective sub-pixels based on the sensing values obtained through the secondary sensing of the bad pixels. find

A first sensing condition for primary sensing of all pixels and a second sensing condition for secondary sensing of bad pixels are set to be different from each other. The second sensing condition is for precise sensing.

During the sensing operation, the voltage difference (ΔV=(1/C)*∫idt) across the feedback capacitor Cfb is proportional to the sensing period dt and inversely proportional to the size C of the feedback capacitor Cfb. Therefore, the sensing discrimination of the value sensed through the current integrator CI increases as the current accumulation time (ie, the sensing period) increases and the size of the feedback capacitor included in the current integrator CI decreases. Improving the sensing discrimination means that the voltage difference ΔV across the feedback capacitor Cfb increases.

As one method for more accurate sensing in secondary sensing, the sensing condition setting unit (not shown) may further reduce the size of the feedback capacitor compared to that in primary sensing, as shown in FIG. 23 . The sensing condition setting unit may reduce the size of the feedback capacitor according to the second sensing condition compared to the size of the feedback capacitor according to the first sensing condition by adjusting the number of switches S1 to Sn turned on. 23, a plurality of feedback capacitors Cfb1 to Cfbn are connected in parallel to the inverting input terminal (-) of the amplifier AMP, and a plurality of switches S1 to Sn are connected to the output terminal of the amplifier AMP. They are connected in parallel with each other, and the feedback capacitors Cfb1 to Cfbn and the switches S1 to Sn may be connected in series with each other.

As another method for more precise sensing in the secondary sensing, the sensing condition setting unit (not shown) may lengthen the sensing period Tsen compared to the first sensing condition as shown in FIG. 24 ( S12 ). As the sensing period Tsen increases, a large amount of current is accumulated in the feedback capacitor Cfb, so the voltage difference ΔV across the feedback capacitor Cfb increases. For example, as shown in FIG. 24 , when the sensing period Tsen increases by a predetermined time ΔS, the voltage difference ΔV across the feedback capacitor Cfb increases from ΔVa to ΔVb. Accordingly, discrimination between the sensing voltages Vsen2a and Vsen2b is improved that much.

As described above, the present invention can dramatically improve the defect rate by compensating for the luminance loss due to the defective sub-pixel using neighboring sub-pixels.

In addition, the present invention can accurately detect the position of a defective sub-pixel within a relatively short time by performing primary sensing and secondary sensing with different sensing conditions.

Furthermore, according to the present invention, not only W dark spots but also R, G, and B dark spots can be corrected, so that an organic light emitting display device with better visibility and reliability can be implemented.

Through the above description, those skilled in the art will understand that various changes and modifications are possible without departing from the spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be determined by the claims.

10: display panel 11: timing controller
12: data driving circuit 13: gate driving circuit
14: data lines 15: gate lines
16: memory 112: luminance calculation unit
113: error detection unit 115: voltage calculation unit
122: position weight generation unit 123: compensation weight generation unit
124: luminance compensation unit 1231: margin analysis unit
1232: position weight adjustment unit

Claims (17)

a display panel including a plurality of pixels, each pixel including a first color subpixel, a second color subpixel, a third color subpixel, and a fourth color subpixel;
a sensing unit connected to the pixels through a plurality of sensing lines, sensing electrical characteristics of subpixels and outputting sensing values;
an error detection unit analyzing the sensed values to find defective sub-pixels that are dark spots and deriving error coordinates corresponding to the defective sub-pixels; and
Compensation coordinates for compensating for luminance loss due to the dark spots are determined based on the error coordinates, luminance contributions to be compensated for at each of the compensation coordinates are calculated, and then the luminance contributions are written into the compensation coordinates. A luminance calculation unit for up-modulating input image data to be
The luminance calculation unit determines locations of subpixels having the same color as the defective subpixel in adjacent pixels adjacent to the defective subpixel, using the compensation coordinates;
The defective subpixel is at least one of the first to fourth color subpixels. delete delete According to claim 1,
The luminance calculator,
a position weight generating unit generating position weights according to the distance between each of the compensation coordinates and the error coordinates;
a compensation weight calculator configured to determine a compensation weight for calculating the luminance share for each of the compensation coordinates, based on the position weight and the luminance according to the input image data to be written to the compensation coordinates; and
and a luminance compensation unit that increases the luminance of the compensation coordinates by the luminance contribution by adding the luminance share obtained by multiplying the input image data to be written to the error coordinates by the compensation weight to the input image data to be written to the compensation coordinates. organic light emitting display. According to claim 4,
The compensation weight calculation unit,
Whether or not the luminance margin capable of realizing the luminance share of the compensation coordinates in addition to the luminance according to the input image data to be written into the compensation coordinates is satisfied within the preset maximum output luminance including the data margin and the threshold voltage margin. a margin analyzer for analyzing P for each of the compensation coordinates; and
and a position weight adjuster configured to adjust the position weight of each of the compensation coordinates based on a result of the luminance margin analysis. According to claim 5,
The position weight adjustment unit,
Among the compensation coordinates, the position weight of the first compensation coordinate in which the luminance margin is not satisfied is reduced to a range where the luminance margin is satisfied, and the position weight of the first compensation coordinate in at least one second compensation coordinate in which the luminance margin is satisfied is reduced. An organic light emitting display device that divides and compensates for According to claim 1,
The sensing unit,
Primary sensing of all pixels according to a first sensing condition to output a corresponding sensing value, and secondary sensing of some pixels according to a second sensing condition different from the first sensing condition to output a corresponding sensing value; ,
The partial pixels are pixels disposed on a horizontal pixel line including the defective sub-pixel. According to claim 1,
In the odd-numbered horizontal pixel line and the even-numbered horizontal pixel line of the display panel, the sub-pixel arrangement order of vertically adjacent pixels is different from each other;
subpixels constituting a first pixel in the odd-numbered horizontal pixel line are arranged in the order of the first color subpixel, the second color subpixel, the third color subpixel, and the fourth color subpixel;
The subpixels constituting the second pixel vertically adjacent to the first pixel in the even-th horizontal pixel line include the third color subpixel, the fourth color subpixel, the first color subpixel, and the second color subpixel. An organic light emitting display device arranged in order of color sub-pixels. A dark spot processing method of an organic light emitting display device having a display panel including a plurality of pixels, each pixel including a first color subpixel, a second color subpixel, a third color subpixel, and a fourth color subpixel, the method comprising:
sensing electrical characteristics of the sub-pixels through a sensing unit connected to the pixels through a plurality of sensing lines and outputting a sensed value;
analyzing the sensed values to find defective sub-pixels that are dark spots, and deriving error coordinates corresponding to the defective sub-pixels; and
Compensation coordinates for compensating for luminance loss due to the dark spots are determined based on the error coordinates, luminance contributions to be compensated for at each of the compensation coordinates are calculated, and then the luminance contributions are written into the compensation coordinates. Including the step of up-modulating the input image data to be,
Determining compensation coordinates for compensating for the luminance loss due to the dark spots,
determining locations of subpixels that display the same color as the defective subpixel in adjacent pixels adjacent to the defective subpixel, using the compensation coordinates, wherein the defective subpixel has the first to fourth colors; A method for processing a dark spot in an organic light emitting display device that is at least one of subpixels. delete delete According to claim 9,
In the step of up-modulating the input image data written to the compensation coordinates,
generating position weights according to the distance between each of the compensation coordinates and the error coordinates;
determining a compensation weight for calculating the luminance share for each of the compensation coordinates based on the position weight and the luminance according to the input image data to be written into the compensation coordinates; and
Increasing the luminance of the compensation coordinates by the luminance contribution by adding the luminance share obtained by multiplying the input image data to be written to the error coordinates by the compensation weight to the input image data to be written to the compensation coordinates, respectively. A method for processing dark spots in an organic light emitting display device. According to claim 12,
The step of determining a compensation weight for calculating the luminance share,
In addition to the luminance according to the input image data to be written into the compensation coordinates, within the preset maximum output luminance including the data margin and the threshold voltage margin, whether the luminance margin capable of implementing the luminance division of the compensation coordinates is satisfied. Analyzing each of the compensation coordinates; and
and adjusting the position weight based on the luminance margin analysis result. According to claim 13,
The step of determining a compensation weight for calculating the luminance share,
Among the compensation coordinates, the position weight of the first compensation coordinate in which the luminance margin is not satisfied is reduced to a range where the luminance margin is satisfied, and the position weight of the first compensation coordinate in at least one second compensation coordinate in which the luminance margin is satisfied is reduced. A dark spot processing method of an organic light emitting display device that divides and compensates for . According to claim 9,
The step of sensing the electrical characteristics of the subpixels and outputting the sensed values,
Primary sensing of all pixels according to a first sensing condition to output a corresponding sensing value, and secondary sensing of some pixels according to a second sensing condition different from the first sensing condition to output a corresponding sensing value step, wherein the some pixels are pixels disposed on a horizontal pixel line including the defective sub-pixel.
a display panel including a plurality of pixels, each pixel including a first color subpixel, a second color subpixel, a third color subpixel, and a fourth color subpixel;
a sensing unit connected to the pixels through a plurality of sensing lines, sensing electrical characteristics of subpixels and outputting sensing values;
an error detection unit analyzing the sensed values to find defective sub-pixels that are dark spots and deriving error coordinates corresponding to the defective sub-pixels; and
Compensation coordinates for compensating for luminance loss due to the dark spots are determined based on the error coordinates, luminance contributions to be compensated for at each of the compensation coordinates are calculated, and then the luminance contributions are written into the compensation coordinates. A luminance calculation unit for up-modulating input image data to be
The sensing unit,
Primary sensing of all pixels according to a first sensing condition to output a corresponding sensing value, and secondary sensing of some pixels according to a second sensing condition different from the first sensing condition to output a corresponding sensing value; ,
The partial pixels are pixels disposed on a horizontal pixel line including the defective sub-pixel. A dark spot processing method of an organic light emitting display device having a display panel including a plurality of pixels, each pixel including a first color subpixel, a second color subpixel, a third color subpixel, and a fourth color subpixel, the method comprising:
sensing electrical characteristics of the sub-pixels through a sensing unit connected to the pixels through a plurality of sensing lines and outputting a sensed value;
analyzing the sensed values to find defective sub-pixels that are dark spots, and deriving error coordinates corresponding to the defective sub-pixels; and
Compensation coordinates for compensating for luminance loss due to the dark spots are determined based on the error coordinates, luminance contributions to be compensated for at each of the compensation coordinates are calculated, and then the luminance contributions are written into the compensation coordinates. Including the step of up-modulating the input image data to be,
The step of sensing the electrical characteristics of the subpixels and outputting the sensed values,
Primary sensing of all pixels according to a first sensing condition to output a corresponding sensing value, and secondary sensing of some pixels according to a second sensing condition different from the first sensing condition to output a corresponding sensing value step, wherein the some pixels are pixels disposed on a horizontal pixel line including the defective sub-pixel.

Images