KR102232872B1 - Organic light emitting display - Google Patents

Abstract

The present invention relates to an organic light-emitting display device capable of electrically compensating for line defects. The timing control unit of the organic light-emitting display device according to the present invention uses sensing data from a data driver to provide adjacent sub-pixels located on the same horizontal line. First and second compensation data are generated, compared, and final compensation data located within the first and second compensation data ranges is output based on the comparison result value.

Description

Organic light emitting display device {ORGANIC LIGHT EMITTING DISPLAY}

The present invention relates to an organic light-emitting display device, and more particularly, to an organic light-emitting display device capable of electrically compensating for line defects.

An image display device that embodies a variety of information on a screen is a core technology in the information and communication era, and is evolving in a direction of thinner, lighter, portable, and high performance. Accordingly, as a flat panel display device capable of reducing the weight and volume, which is a disadvantage of a cathode ray tube (CRT), an organic light-emitting display device that displays an image by controlling the amount of light emitted from an organic light-emitting layer is in the spotlight.

In the organic light emitting diode display, a plurality of pixels are arranged in a matrix to display an image. Here, each pixel includes a light-emitting element and a pixel driving circuit including a plurality of transistors that independently drive the light-emitting element.

In the OLED display, a minute short occurs between signal lines due to external factors such as static electricity, as well as internal factors such as particles, cracks, misalignment of pads, and narrow wiring layouts introduced during a manufacturing process.

Such a minute short is not recognized at first, but when the organic light emitting display device is continuously driven, it proceeds to a line defect. When the characteristic of the driving transistor is sensed using the abnormal sub-pixel in which the progressive line defect has occurred, compensation data is abnormally formed. In particular, since white sub-pixels have an average amount of usage higher than each of the red, green, and blue sub-pixels, the deterioration speed of the white sub-pixel is relatively increased compared to the deterioration speed of the other sub-pixels. Accordingly, the sensing value of the white sub-pixel is sensed higher than that of the other sub-pixels. The compensation data of the white sub-pixels sensed with a high sensing value is set lower than the compensation data of the sub-pixels of other colors, resulting in dark line defects in the white sub-pixels, and bright line defects in the red, green, and blue sub-pixels. have.

The present invention is to solve the above problem, and the present invention is to provide an organic light emitting display device capable of electrically compensating for line defects.

In order to achieve the above object, an organic light emitting display device according to the present invention includes a display panel including a unit pixel consisting of red, green, blue, and white sub-pixels; A data driver configured to generate sensing data by sensing characteristics of transistors formed in each of the sub-pixels; And a timing controller for controlling the data driver. In particular, the timing controller of the organic light emitting diode display according to the present invention generates first and second compensation data of adjacent sub-pixels located on the same horizontal line by using sensing data, and determines whether the second compensation data is normal. And outputting final compensation data located within the first and second compensation data ranges according to the determination result.

The organic light emitting diode display according to the present invention generates final compensation data by replacing compensation data abnormally formed due to a line defect with compensation data or average data of adjacent sub-pixels. Accordingly, the organic light emitting diode display according to the present invention can electrically compensate even if a line defect occurs, thereby improving reliability by preventing the occurrence of bright lines and dark lines.

1 is a block diagram illustrating an organic light emitting display device according to the present invention.
FIG. 2 is a diagram illustrating a sub-pixel of the organic light emitting diode display illustrated in FIG. 1.
FIG. 3 is a diagram illustrating a timing control unit illustrated in FIG. 1.
4 is a block diagram for explaining in detail the data processing unit shown in FIG. 3.
5A and 5B are diagrams for explaining driving of the data output unit illustrated in FIG. 4.
6 is a block diagram specifically illustrating a second embodiment of the data processing unit shown in FIG. 3.
7 is a flowchart illustrating a first embodiment of a method of driving the organic light emitting display device illustrated in FIG. 1.
8 is a flowchart illustrating a second exemplary embodiment of a method of driving the organic light emitting display device illustrated in FIG. 1.
9 is a block diagram illustrating in detail a third embodiment of the data processing unit shown in FIG. 3.
10 is a flowchart illustrating a method of driving an organic light emitting display device having a data processing unit illustrated in FIG. 9.

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

1 is a block diagram illustrating an organic light emitting display device according to the present invention.

The organic light emitting display device illustrated in FIG. 1 includes a data driver 104, a gate driver 106, a panel driver 108 including a timing controller 110, and a light emitting display panel 102.

The light emitting display panel 102 includes a plurality of unit pixels P including a red sub-pixel SPR, a green sub-pixel SPG, a blue sub-pixel SPB, and a white sub-pixel SPW. The arrangement of sub-pixels in each unit pixel P is very diverse, and the red sub-pixel SPR, white sub-pixel SPW, blue sub-pixel SPB, and green sub-pixel SPG shown in FIG. The order arrangement is only a specific example and is not limited thereto.

Each of the sub-pixels SPR, SPG, SPW, and SPB is formed in a pixel area provided at the intersection of the gate line GL and the data line DL, and each of the sub-pixels SPR, SPG, SPW, and SPB is shown in FIG. 2. As shown in FIG. 1, a switching transistor T_SW, a driving transistor T_Dr, a storage capacitor Cst, a sensing transistor T_Se, and an organic light emitting diode OLED are provided. The organic light emitting diode OLED operates to emit light according to a driving current formed by the transistor T_Dr. The switching transistor T_Sw performs a switching operation so that the data signal supplied through the data line DL is stored as a data voltage in the storage capacitor Cst in response to the gate signal supplied through the gate line GL. The driving transistor T_Dr operates so that a driving current flows between the high potential line VDD and the low potential line VSS according to the data voltage stored in the storage capacitor Cst. The sensing transistor T_Se supplies the reference voltage Vref supplied to the sensing line SEL to the source electrode of the driving transistor T_Dr in response to a gate signal supplied through the gate line GL. The threshold voltage of the driving transistor DR is sensed through the sensing transistor T_Se and the sensing line SEL, and the data voltage is compensated in proportion to a difference between the sensed threshold voltage and the reference threshold voltage. Since the configuration of the sensing transistor T_Se and the sensing line SEL is very diverse, the structure of FIG. 2 is a specific example and is not limited thereto.

The panel driver 108 includes a data driver 104, a gate driver 106, and a timing controller 110.

The data driver 104 converts digital pixel data into an analog data voltage using a data control signal DCS and a gamma voltage from the timing controller 110, and converts the changed analog data voltage to a data line ( DL). In particular, the data driver 104 generates the voltage sensed through the sensing transistor T_Se as sensing data in digital form and supplies it to the timing controller 108, and controls signals and gamma from the timing controller 108. The digital compensation data DATA is converted into an analog data voltage using the voltage, and the changed analog data voltage is supplied to the data line DL.

The gate driver 106 supplies a high or low gate voltage to the gate lines GL1 to GLm formed on the light emitting display panel 102 in response to the gate control signal GCS from the timing controller 110. .

The timing controller 110 stores the sensing data SData input from the data driver 104 and compensation values determined based on the sensing data SData in a memory including a plurality of lookup tables. Then, after generating digital compensation data DATA by varying data input from the outside using compensation values, the digital compensation data DATA is supplied to the data driver 104.

To this end, the timing control unit 110 includes a control signal generation unit 120 and a data processing unit 130 as shown in FIG. 3.

The control signal generator 120 generates a gate control signal (GCS) and a data control signal (DCS) for controlling driving timings of the gate driver 106 and the data driver 104 based on a synchronization signal input from the outside. do. The generated gate control signal GCS is supplied to the gate driver 106 and the data control signal DCS is supplied to the data driver 104.

The data processing unit 130 generates digital compensation data DATA by correcting the input data RGB based on the sensing data SData from the data driving unit 104, and then converts the digital compensation data DATA to the data driving unit. Supply to (104).

To this end, the data processing unit 130 includes a four-color data conversion unit 132, a data correction unit 134, a look-up table 136, a data classification unit 138, and a comparison unit 140 as shown in FIG. 4. ) And a data output unit 144.

The four-color data conversion unit 132 converts red, green, and blue input data RGB of each unit pixel input from the outside in a frame unit, into red, green, blue, and white pixel data RGBW. . For example, the four-color data converter 132 converts input data RGB having a minimum gray level value (or a common gray level value) from the red, green, and blue input data RGB of a unit pixel into white pixel data ( W), and reflecting the generated white pixel data W to the red, green, and blue input data RGB, respectively, to generate red, green, and blue pixel data R, G, and B. At this time, the four-color data conversion unit 112 subtracts and calculates the white pixel data W from each of the red, green, and blue input data RGB, and performs red, green, and blue pixel data (R, G, B). Each can be created.

The lookup table 136 stores sensing data SData from the data driver 104 and a compensation value determined based on the sensing data. Here, the compensation value is a value obtained by compensating for a deviation of a data voltage for a change in sensing data, for example, the sensing data SData by sensing the threshold voltage of the driving transistor T_Dr, through a pre-simulation process. This compensation value is individually set for each sensing data sensed by the threshold voltage of the driving transistor T_Dr.

The data correction unit 134 corrects the red, green, blue, and white pixel data RGBW from the four-color data conversion unit 132 by using the compensation value stored in the lookup table 134 to obtain digital compensation data R′. G'B'W') is generated, and the digital compensation data R'G'B'W' is supplied to the data classification unit 138.

The data classification unit 138 classifies red, green, blue, and white compensation data R'G'B'W' input from the data correction unit 134 by color. Here, the data classification unit 138 classifies compensation data R'G'B'W' of sub-pixels located on the same horizontal line by color.

The comparison unit 140 compares two compensation data adjacent to the left and right that implement the same color located on the same horizontal line that is classified and supplied by the data classification unit 138, and generates a comparison signal CS according to the comparison result. It is generated and supplied to the data output unit 144. That is, the comparison unit 140 generates a high logic comparison signal CS when the difference between the two first and second compensation data values adjacent to each other implementing the same color on the same horizontal line is greater than or equal to the threshold value, and When the difference is less than the threshold value, a low logic comparison signal CS is generated.

For example, as illustrated in FIGS. 5A and 5B, the first and second compensation of the n-2th and n-1th white sub-pixels Wn-2 and Wn-1 positioned on the same horizontal line Since the absolute value (|14-12|=2) of the difference between the data values is less than the threshold value (for example, 4), the comparison signal CS of the row logic is generated. And, the absolute value of the difference between the first and second compensation data values of the n-1th and nth white sub-pixels Wn-1 and Wn located on the same horizontal line (│12-20│=8) Since it is equal to or greater than this threshold (for example, 4), a high logic comparison signal CS is generated.

The data output unit 144 outputs the second compensation data of the current sub-pixel as it is according to the result of the comparison unit 140, or is located within the range of the first compensation data of the previous sub-pixel and the second compensation data of the current sub-pixel. Data is output as final compensation data. That is, when the comparison signal CS of the row logic is input from the comparison unit 140, the data output unit 144 determines that the line defect is not normal and performs a second compensation as shown in FIGS. 5A and 5B. The data is output as it is as final compensation data DATA of the current sub-pixel. In addition, when a high logic comparison signal is input from the comparison unit 140, the data output unit 144 determines that a line defect has occurred abnormally, and the first compensation data of the previous sub-pixel and the second compensation of the current sub-pixel are determined. Data located within the data range is output as final compensation data DATA of the current sub-pixel. For example, as shown in FIG. 5A, the data output unit 144 transfers the first compensation data 12 of the previous sub-pixel Wn-1 that implements the same color positioned on the same horizontal line to the current sub-pixel ( Wn) of the final compensation data (12). In addition, the data output unit 144 includes the first compensation data 12 of the previous sub-pixel Wn-1 that implements the same color positioned on the same horizontal line, and the current sub-pixel Wn, as shown in FIG. 5B. The average data 16 of the second compensation data 20 of may be output as final compensation data. In this case, the data processing unit 130 may further include an average data generation unit 142 positioned between the data classification unit 138 and the data output unit 144 as shown in FIG. 6. That is, the average data generation unit 142 is the average data (Ra'Ga'Ba'Wa') of the first and second compensation data that implements the same color in the same horizontal line classified and supplied by the data classification unit 138. ) Is calculated and supplied to the data output unit 144. In addition, the average data generation unit 142 may calculate the average data (Ra'Ga'Ba'Wa') of compensation data values of all sub-pixels implementing the same color on the same horizontal line and supply it to the data output unit 144. have.

7 is a flowchart illustrating a method of driving an organic light emitting display device according to the present invention.

First, an image is displayed on the light emitting display panel 102, and sensing data is generated by sensing a threshold voltage of the driving transistor T_Dr (S102). Compensation data of each sub-pixel is generated by using the sensing data (S104). Then, the first and second compensation data DATAn-1 and DATAn of two adjacent sub-pixels implementing the same color positioned on the same horizontal line are compared (S106).

If the comparison value is greater than or equal to the threshold value, the compensation data of the current sub-pixel is determined as abnormal compensation data in which a line defect has occurred, and the average data or the first compensation data DATAn-1 of the previous sub-pixel implementing the same color are determined. The final compensation data of the current sub-pixel is output (S108) to perform normal driving (S112).

On the other hand, if the comparison value is less than the threshold value, the compensation data of the current sub-pixel is determined as normal compensation data without line defects, and the second compensation data DATAn is output as the final compensation data of the current sub-pixel as it is. (S110) to drive normally (S112).

Meanwhile, in the present invention, it is determined whether the difference between the first and second compensation data DATAn-1 and DATAn of two adjacent sub-pixels implementing the same color located on the same horizontal line exceeds a threshold value. Although described as an example, in addition to the comparison unit 140 and the data output unit 144 shown in FIGS. 4 and 6, the compensation data R'G'B' of the red, green, and blue sub-pixels included in the current unit pixel ) May be determined whether it is normal compensation data or abnormal compensation data by determining a difference between the compensation data W′ of the white sub-pixel.

That is, as shown in FIG. 8, if the compensation data R'G'B' of the red, green, and blue sub-pixels is larger than the compensation data W'of the white sub-pixel (S206), each sub-pixel of the current unit pixel The compensation data DATA'n of the pixel is determined as abnormal compensation data. Accordingly, the data output unit 144 converts the final compensation data of the current unit pixel into the first compensation data DATA′n-1 of the previous unit pixel or the first and second compensation data DATA′n-1,DATA′. The average data, which is the average of n), is substituted and supplied to the data driver 104 (S208).

And, if the compensation data (R'G'B') of the red, green, and blue sub-pixels is smaller than the compensation data (W') of the white sub-pixel (S206), the compensation data of each sub-pixel included in the current unit pixel Is determined as normal compensation data. Accordingly, the data output unit 144 supplies the second compensation data DATA'n of the current unit pixel as final compensation data to the data driver 1104 (S210).

In addition, the data processing unit 130 of the present invention may include two comparison units as shown in FIG. 9. That is, as shown in FIG. 9, the first comparison unit 140a determines whether the difference between the first and second compensation data DATAn-1 and DATAn of two adjacent sub-pixels implementing the same color exceeds the threshold value. Is determined to generate a first comparison signal CS1. In addition, the second comparison unit 140b determines a difference between the compensation data R'G'B' of the red, green, and blue sub-pixels included in the current unit pixel and the compensation data W'of the white sub-pixels. A second comparison signal CS2 is generated. Here, the first comparison unit 140a shown in FIG. 9 is the same as the comparison unit 140 shown in FIG. 4, and the second comparison unit 140b is the same as the comparison operation described in step S206 shown in FIG. Therefore, a detailed description thereof will be omitted.

In this case, the data output unit 144 may transmit the second compensation data DATAn' as it is, according to the first comparison signal CS1 or the second comparison signal CS2, as shown in FIG. 10. Output as compensation data (S312), final compensation data (DATA'n-1) or average data located within the range of the first and second compensation data (S310).

As described above, the organic light emitting display device according to the present invention generates final compensation data by replacing compensation data abnormally formed due to line defects with compensation data or average data of adjacent sub-pixels. Accordingly, the organic light emitting diode display according to the present invention can electrically compensate even if a line defect occurs, thereby improving reliability by preventing the occurrence of bright lines and dark lines.

The above description is merely illustrative of the present invention, and various modifications may be made without departing from the technical spirit of the present invention by those of ordinary skill in the technical field to which the present invention pertains. Therefore, the embodiments disclosed in the specification of the present invention do not limit the present invention. The scope of the present invention should be construed by the following claims, and all technologies within the scope equivalent thereto should be construed as being included in the scope of the present invention.

102: display panel 104: data driver
106: gate driver 108: panel driver
110: timing control unit

Claims (5)

A display panel including a unit pixel composed of red, green, blue, and white sub-pixels;
A data driver configured to generate sensing data by sensing characteristics of transistors formed in each of the sub-pixels;
Using the sensing data, first and second compensation data of adjacent sub-pixels located on the same horizontal line are generated, determine whether the second compensation data is normal, and the first and second compensation data are determined according to the determination result. It has a timing control unit for outputting the final compensation data located within the compensation data range,
When the difference between the first and second compensation data is less than a threshold, the timing controller determines the second compensation data as normal and supplies the final compensation data of the current sub-pixel to the data driver,
When the difference exceeds a threshold value, the first compensation data or the average data of the first and second compensation data is supplied to the data driver as the final compensation data of the current sub-pixel. Device. delete The method of claim 1,
The timing control unit
A data correction unit generating the first and second compensation data of the previous and the current sub-pixels implementing the same color positioned on the same horizontal line by using sensing data from the data driver;
A data classification unit for classifying the first and second compensation data from the data correction unit according to color;
A comparison unit comparing differences between the first and second compensation data classified and supplied by the data classification unit;
If the difference between the first and second compensation data is less than the threshold value, the second compensation data of the current sub-pixel is determined as normal and supplied to the data driver as it is, and if the difference exceeds the threshold value, the first compensation An organic light-emitting display device comprising: a data output unit supplying data to the data driver. The method of claim 1,
The timing control unit
A data correction unit generating the first and second compensation data corresponding to previous and current sub-pixels implementing the same color positioned on the same horizontal line by using sensing data from the data driver;
A data classification unit for classifying the first and second compensation data from the data correction unit according to color;
An average data generation unit that calculates average data of the first and second compensation data classified and supplied by the data classification unit;
A comparison unit comparing differences between the first and second compensation data classified and supplied by the data classification unit;
If the difference between the first and second compensation data is less than a threshold value, the second compensation data of the current sub-pixel is determined as normal and supplied to the data driver as it is, and if the difference exceeds the threshold value, the first And a data output unit supplying average data, which is an average of second compensation data, to the data driver. The method of claim 1,
The timing control unit
A data correction unit for generating the first and second compensation data corresponding to previous and current unit pixels positioned on the same horizontal line by using sensing data from the data driver;
A data classification unit for classifying each of the first and second compensation data from the data correction unit according to color;
A comparison unit comparing a difference between compensation data of red, green, and blue sub-pixels included in second compensation data of a current unit pixel classified and supplied by the data classifying unit and compensation data of white sub-pixels;
If the compensation data of the red, green, and blue sub-pixels is smaller than the compensation data of the white sub-pixel, the second compensation data of the current unit pixel is determined as normal and the second compensation data is supplied to the data driver as it is, When the compensation data of the red, green, and blue sub-pixels is larger than the compensation data of the white sub-pixel, the first compensation data or average data that is an average of the first and second compensation data is the final compensation data of the current unit pixel. And a data output unit supplied to the data driver.

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