KR20160043744A - Organic light emitting diode display device - Google Patents

Abstract

The present invention relates to an OLED display device including a white sub-pixel, which is capable of performing precise image display even when a defect occurs in the white sub-pixel. The OLED display device according to the present invention comprises: a display panel which includes a plurality of pixels, wherein one of the pixels is formed of a white sub-pixel and a colored sub-pixel; a data drive unit which supplies data voltage to the pixel; a gate drive unit which selects the pixel to be supplied with the data voltage; and a timing controller which converts video data, input from the outside, to first pixel data to be supplied to a non-defective one of the pixels, converts the video data into second pixel data to be supplied only to a colored sub-pixel included in a defective pixel, with respect to the defective pixel, i.e., a sub-pixel for which a defect has occurred in its white sub-pixel, and transfers the first pixel data and the second pixel data to the data drive unit.

Description

 TECHNICAL FIELD [0001] The present invention relates to an organic light emitting diode (OLED) display device,

The present invention relates to an organic light emitting diode (OLED) display device, and more particularly, to an organic light emitting diode display device capable of accurately displaying an image even when a white subpixel is defective in an organic light emitting diode display device including white subpixels .

An organic light emitting diode (OLED) display device is a self-luminous device that emits an organic light emitting layer by recombination of electrons and holes. It is expected to be a next-generation display device because it has a high luminance, a low driving voltage and an ultra-thin film.

Such an OLED display device emits light by the current supplied to the OLED element by the driving TFT provided in the pixel driving circuit, and the light emission amount is increased or decreased in proportion to the supplied current. Therefore, the driving TFT controls the amount of current to control the emission of the OLED.

Such an OLED display device is rapidly deteriorated when the amount of current is increased to emit light with a high luminance, thereby deteriorating the characteristics. For example, when a high-luminance image is displayed for a long time, the degradation progresses and the characteristics of the OLED element deteriorate, making it difficult to realize a desired quality image. In order to solve this problem, there is a method of increasing the light emitting area, but it is not easy to increase the light emitting area due to the limited panel area.

Therefore, in recent OLED display devices, a red (R), a green (G), and a blue (B) colors are formed so as to display an image of achromatic (white, black, gray) White (W) subpixels are added in addition to the subpixels to assist the luminance representation.

When defects are generated in a white pixel in an OLED display composed of four color subpixels, an image is displayed by three color subpixels except a white pixel. When driving with only three color subpixels, luminance and chroma are accurately expressed There is a problem that the display quality is deteriorated.

Accordingly, it is an object of the present invention to provide an OLED display device capable of displaying an accurate image even when a defect occurs in a white sub-pixel in an OLED display device including a white sub-pixel.

In order to achieve the above object, in an OLED display device according to the present invention, when a defect occurs in white subpixels of some pixels in an OLED display panel in which four color subpixels of white, red, blue and green form one pixel , The normal pixel and the defective pixel are supplied with the data converted by the first and second color coordinates determined to display the same image with respect to the same data so that the defective pixel is detected by the colored sub- A timing controller, a data driver, a gate driver, and a display panel for outputting the same image as the image outputted by the pixel.

In the OLED display according to the present invention, only pixels having defects in white subpixels among the four color subpixels are driven by the three color subpixels, and three color subpixels are formed according to the color coordinates previously configured to correspond to the four color subpixels The same image as the image displayed by the four color subpixels can be displayed even if defects occur in the white subpixels.

The OLED display according to the present invention can be used without discarding the defective display panel and can stably provide a high display quality image even when defects are generated during use.

1 is a view illustrating an organic light emitting diode display according to an embodiment of the present invention.
2 is an exemplary diagram showing an example of the circuit configuration of subpixels constituting the display panel.
3 is a flow chart for explaining driving of an OLED display according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be noted that the drawings denoted by the same reference numerals in the drawings denote the same reference numerals whenever possible, in other drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. And certain features shown in the drawings are to be enlarged or reduced or simplified for ease of explanation, and the drawings and their components are not necessarily drawn to scale. However, those skilled in the art will readily understand these details.

1 is a view illustrating an organic light emitting diode display according to an embodiment of the present invention. 2 is an exemplary diagram showing an example of the circuit configuration of subpixels constituting the display panel.

1 and 2, an organic light emitting diode (OLED) display device according to the present invention includes a display panel 10, a data driver 20, a gate driver 30, and a timing controller 40 ).

In the present invention, one pixel is constituted by a white subpixel and a plurality of colored subpixels, and pixel data different from the defective pixel of the white subpixel and the normal pixel and data voltages generated thereby are supplied and driven . Accordingly, the present invention can display an image of the same quality as a normal pixel even when a defect occurs in a white sub-pixel, thereby maintaining a high-quality image display quality, and continuously displaying It is possible to make the device usable.

The display panel 10 includes data lines DLm: DL1 to DLm (where m is a natural number) formed in the first direction of the display panel 10 and a gate line GLn (DLm) formed in a direction orthogonal to the data line DLm : GL1 to GLn, where n is a natural number), and a pixel P formed in a pixel region defined at the intersection of the gate line GLn and the data line DLm and having a pixel circuit.

The pixel P constitutes one pixel P by the white subpixel W and the colored subpixel RGB. Here, the colored subpixels RGB each include a red subpixel R, a green subpixel G, and a blue subpixel B, respectively. Each of the sub-pixels RGBW is selected by a gate signal, and when selected, charges the data voltage Vdata supplied from the data driver 20 to emit light.

In particular, the pixel P of the present invention is driven by being divided into a normal pixel P and a defective pixel P '. Specifically, the normal pixel P is a pixel whose normal white subpixel W is normal. The first pixel data DATA supplied by the timing controller 40 is supplied to the first data voltage Vdata ). The defective pixel P 'is a pixel in which the white sub-pixel W is defective and the light emission of the white sub-pixel W is not normally performed. The defective pixel P 'emits the second pixel data DATA' supplied from the timing controller 40 by the second data voltage Vdata converted by the data driver 20. [ In particular, the defective pixel P 'is arranged so as to represent the image by the remaining colored subpixels (RGB) constituted in the same pixel P' without driving the defective white subpixel W, DATA ') and the second data voltage (Vdata'). This will be described in more detail below.

Each of the subpixels SP may include first and second switching TFTs SW1 and SW2, a driving TFT DT, a storage capacitor Cst, and an OLED element. Here, the circuit diagram of the subpixel SP shown in FIG. 2 can be applied to various types of circuit configurations known only by way of example, and the present invention is not limited thereto.

The first switching TFT SW1 of the sub-pixel SP has a gate electrode connected to the gate line GLo, a first electrode connected to the data line DLp, a second electrode connected to the first node n1, Is connected to the gate electrode of the driving TFT DT. The driving TFT SW2 has a gate electrode connected to the first node n1, a first electrode connected to the first power supply line VDD, and a second electrode connected to the second node n2. The storage capacitor Cst is connected between the first node n1 and the second node n2 and the OLED element OLED is connected between the second node n2 and the second power line Vss. The second switching TFT SW2 has a first electrode connected to the reference line REF, a second electrode connected to the second node, and a gate electrode connected to the control signal line. Here, the control signal line may be one of the gate lines or a separately formed signal line, but the present invention is not limited thereto.

In the display period, the second switching TFT SW2 supplies the reference voltage supplied through the reference line to the second node n2 to initialize the second node n2, and the first switching TFT SW1 supplies the reference voltage supplied through the gate line And supplies the data voltage supplied through the data line DLp to the first node n1.

The storage capacitor Cst charges the difference voltage between the data voltage (Vdata) and the reference voltage in the display mode and drives the drive TFT on by the charged voltage.

The driving TFT DT is turned on by the voltage supplied from the storage capacitor Cst and supplies the current supplied by the power supply from the first power supply line to the OLED element OLED to emit light to the OLED element OLED .

The data driver 20 converts the first pixel data DATA or the second pixel data DATA 'transferred from the timing controller 40 into the first data voltage Vdata or the second data voltage Vdata' And supplies the converted first and second data voltages Vdata and Vdata 'to the subpixel SP selected by the data control signal DCS transmitted from the timing controller 40.

The gate driver 30 supplies the gate signal to the gate line GLn of the display panel 10 in response to the gate control signal GCS from the timing controller 40. [ The gate driving unit 30 supplies a gate signal for sequentially driving the gate line GLn in response to the gate control signal GCS.

The timing controller 40 controls the data driver 20 and the gate driver 30 to supply a data voltage to the pixel P so that an image is displayed.

In particular, the timing controller 40 collects information on the normal pixel P and the defective pixel P ', and generates pixel data generated by different color coordinates on the normal pixel P and the defective pixel P' And transmits the generated pixel data to the data driver 20.

Specifically, the timing controller 40 converts input data input from the outside into pixel data (DATA) in order to transmit the data to the data driver 20. At this time, the timing controller 40 generates the pixel data DATA supplied to the normal pixel P by performing compensation with the first color coordinate, and the pixel data DATA 'supplied to the defective pixel P' By performing compensation by two color coordinates.

In particular, the timing controller 40 compensates for the pixel having a defect in the white subpixel W by the second color coordinate, converts it into the pixel data DATA ', and transmits the pixel data DATA' to the data driver.

That is, the timing controller 40 controls the red subpixel R, the blue subpixel B, and the green subpixel R, which are the white subpixels and the colored subpixels SP, for the pixels for which no defect is generated in the white subpixel W. [ (DATA) to convert the input data (Idata) into the first pixel data (DATA) so that the image is expressed by the four pixels of the pixel (G). At this time, the timing controller 40 outputs the input data (Idata) to the first pixel data (DATA) through the first color coordinates in which the color values and the compensation values for the four pixels are predetermined .

On the other hand, in the timing controller 40, the input data to be supplied to the defective pixel P 'including the defective white subpixel W is divided into three subpixels RGB by the color subpixel SP, The input data Idata is converted into the second pixel data DATA '. At this time, the timing controller 40 outputs the input data Idata to the second pixel data DATA ', which is the data of each of the three subpixels, through the second color coordinate in which the color values for the three pixels and the compensation value for the three pixels are predetermined, ). The second color coordinates refer to a color coordinate corresponding to the first color coordinate and a color coordinate to which the compensation value for each sub-pixel is applied so that the hue of the first color coordinate is represented by three sub-pixels.

More specifically, in order to represent an image represented by four sub-pixels WRGB by three sub-pixels RGB, a white balance must be adjusted and luminance compensation for each sub-pixel must be performed do. Therefore, the second color coordinate is adjusted so that the color coordinates represented by the normal pixel P can be equally represented by the defective pixel P 'driven only by the three sub-pixels RGB. And the compensation value is added to compensate for the difference of the characteristics of each sub pixel (RGB).

The timing controller 40 transmits the first and second pixel data DATA and DATA 'to be supplied to the finishing pixel P and the defective pixel P' to the data driver 20, Is supplied to the pixels selected by the gate driver 30, thereby displaying an image.

3 is a flow chart for explaining driving of an OLED display according to the present invention.

Referring to FIG. 3, the driving of the OLED display according to the present invention includes a preparation step S00, a sensing step S10, a driving determination step S20, a defect and normal pixel driving preparation step S31 and S36, Steps S41 and S46, and a driving step S50.

The preparation step S00 is a step in which the first color coordinate and the second color coordinate are prepared for driving the OLED display. In this preparation step, a first color coordinate for generating first pixel data (DATA) for expressing the input data (Idata) by the four-color sub-pixel (RGBW) is provided. When the image is represented by the normal pixel P constituted by the four-color sub-pixel RGBW, the first color coordinate may be a coordinate form or a value for the color, saturation, It is defined as a numerical value. In addition, a compensation value for compensating the threshold voltage or mobility is defined in the first color coordinate according to the characteristics of each of the sub-pixels RGBW constituting the normal pixels P, respectively. That is, a compensation value for allowing the subpixels RGBW of the normal pixel P to correctly express the color designated by the first color coordinate is included in the first color coordinate.

The first color coordinates may be provided for each subpixel to form a color coordinate including a compensation value for each subpixel. Only one basic first color coordinate is provided for all the subpixels, and the compensation value for each subpixel is separately The compensation value may be additionally applied after applying the first color coordinate, but the present invention is not limited thereto.

Similarly, a second color coordinate corresponding to the first color coordinate is also provided. This second color coordinate has a value for hue, saturation and brightness so that an image which can be represented by a normal pixel P is expressed by three color subpixels (RGB) when an image is represented by three color subpixels (RGB) Coordinate or a resin value. Also, in the second color coordinate system, a compensation value for compensating the threshold voltage or the mobility is defined according to the characteristics of each of the sub-pixels RGB similarly to the first color coordinate system. Such a second color coordinate may also be provided for each subpixel (RGB) including a compensation value for each subpixel (RGB) as in the first color coordinate system, and a second color coordinate may be provided and each subpixel The compensation values for the subpixels (RGB) may be provided, but the present invention is not limited thereto.

The sensing step S10 is a step in which the timing controller 40 detects whether any of the white sub-pixels W of the display panel 10 has a defect. In this sensing step S10, the position of the sub-pixel in which the defect occurs in the white sub-pixel W and the position thereof are confirmed by a known method.

The drive determination step S20 is a step of determining whether the pixel data to be supplied in the current sequence is supplied to the subpixels of the defective pixel or the subpixel of the normal pixel. When the pixel data is supplied to the defective pixel in the driving determination step S20, the following steps S36 and S46 are performed. When pixel data is supplied to the normal pixel, the following steps S31 and S41 are performed. In the following, each step will be described separately.

The defect and normal pixel driving preparation steps (S31 and S36) are a step in which the timing controller 40 calls the first color coordinate or the second color coordinate depending on whether the pixel to which the current pixel data is to be supplied is a normal or a defective pixel. That is, the timing controller 40 calls the first color coordinate when the pixel to be supplied with the current pixel data is the normal pixel P in the drive determination step S20, and calls the second color coordinate when the pixel is defective pixel P ' .

The data conversion steps S41 and S46 are steps in which the timing controller 40 converts the input data into the pixel data (DATA, DATA ') by the first color coordinate system or the second color coordinate system. The timing controller 40 supplies the input data Idata to each of the sub pixels RGBW of the normal pixel P by using the first color coordinate if the pixel P to which the current pixel data is to be supplied is a normal pixel P Into the first pixel data DATA (S41). On the other hand, when the pixel P to which the current pixel data is to be supplied is a defective pixel P, the timing controller 40 uses the second color coordinate to input data Idata to the colored subpixel RGB of the defective pixel P ' To the second pixel data DATA 'to be supplied.

In the driving step S50, the timing controller 40 transmits the first or second pixel data DATA and DATA 'to the data driver 20, and the data driver 20 supplies the first or second pixel data (DATA, DATA ') into a first data voltage (Vdata) or a second data voltage (Vdata') and supplies the selected data to the selected subpixel (RGBW or RGB). The subpixels RGBW or RGB supplied with the first or second data voltages Vdata and Vdata 'emit light by the supplied first or second data voltages Vdata and Vdata' .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, . ≪ / RTI > Accordingly, such modifications are deemed to be within the scope of the present invention, and the scope of the present invention should be determined by the following claims.

10: Display panel
20:
30: Gate driver
40: Timing controller

Claims (4)

A display panel having a plurality of pixels, wherein one pixel is constituted by white subpixels and colored subpixels;
A data driver for supplying a data voltage to the pixel;
A gate driver for selecting the pixel to which the data voltage is to be supplied; And
And converting the image data input from the outside into the first pixel data for supplying to the normal pixel among the pixels, wherein, for the defective pixel which is a sub-pixel in which the defect occurs in the white sub-pixel, And a timing controller for converting the first pixel data and the second pixel data into second pixel data for supplying only the subpixels, and for transmitting the first pixel data and the second pixel data to the data driver. The method according to claim 1,
The timing controller
A first color coordinate system for converting the image data into the first pixel data supplied to the normal pixel,
And a second color coordinate where a color coordinate corresponding to the first color coordinate is stored such that the image data is represented by the colored subpixel of the combining pixel. 3. The method of claim 2,
The timing controller
And the second pixel data is generated by compensating the image data according to the second color coordinate. 3. The method of claim 2,
Wherein the second color coordinates are generated by adjusting at least one of white balance, color temperature, and luminance for arbitrary coordinates of the first color coordinate.

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