KR20190047438A - Organic light emitting diode display - Google Patents

Abstract

The present invention relates to an organic light emitting diode display device capable of increasing lifetime by equalizing deterioration of each sub pixel in a display panel. According to the present invention, the organic light emitting diode display device has a plurality of sub pixels which are arranged on each of a plurality of display areas. At least one of the plurality of sub pixels has a light emitting area which is differently formed in accordance with a position of the display area so as to equalize deterioration of each sub pixel, thereby increasing the lifetime.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] 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 improving lifetime by uniformly degrading each sub pixel in a display panel.

The image display device that realizes various information on the screen is a core technology of the information communication age and it is becoming thinner, lighter, more portable and higher performance. Accordingly, a flat panel display device capable of reducing weight and volume, which is a disadvantage of a cathode ray tube (CRT), has attracted attention. Such flat panel display devices include a liquid crystal display (LCD) using a liquid crystal, an OLED display using an organic light emitting diode (OLED), an electrophoretic display using an electrophoretic particle ; EPD).

Among them, the OLED display uses an OLED element, which is self-emitting by the organic light emitting layer between the anode and the cathode, as the sub-pixel, and exhibits excellent image quality such as excellent contrast ratio characteristics. .

However, due to the self-emission characteristics of the OLED display device, the OLED display device is deteriorated with the elapse of driving time, and a difference in brightness is caused by a deterioration difference between adjacent unit pixels, and a color difference occurs due to a deterioration difference between sub- do. Such a difference in brightness and color is perceived by the user and is perceived as a permanent afterimage.

The present invention has been made to solve the above problems, and it is an object of the present invention to provide an organic light emitting diode display device capable of improving deterioration of each sub-pixel in a display panel,

According to an aspect of the present invention, there is provided an organic light emitting diode (OLED) display device including a plurality of sub-pixels disposed in a plurality of display regions, wherein at least one of the plurality of sub- The light emitting area is formed differently.

In the present invention, the light emission areas of the respective sub-pixels are formed differently depending on the position of the display area. That is, in the present invention, the light emitting area of the white sub-pixels arranged in the outer display area is wider than that of the white sub-pixels arranged in the main display area, and is arranged in the outer display area which is the light emitting area of the red sub- Is wider than the red sub-pixel. Accordingly, in the present invention, the white afterimage in the outer display area, the time of occurrence of the red afterimage in the main display area can be maximally delayed, and the lifespan of the sub pixels arranged in the outer display area and the main display area becomes equal, .

1 is a block diagram showing an organic light emitting diode display device according to the present invention.
2 is a view showing each sub-pixel of the display panel shown in Fig.
FIG. 3 is a view showing a structure in which the display panel shown in FIG. 1 is divided into a plurality of outer display areas and a plurality of main display areas.
FIG. 4 is a view for explaining the light emitting area of each sub-pixel in the main display area and the sub-display area shown in FIG.
FIG. 5A is a view showing sub-pixels arranged in the outer display area shown in FIG. 4, and FIG. 5B is a view showing sub-pixels arranged in the main display area shown in FIG.

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

1 is a block diagram showing an OLED display device having an image processing circuit according to the present invention.

1 includes a display panel 100, a panel driver including a data driver 108 and a scan driver 106 for driving the display panel 100, a timing controller (not shown) for controlling the panel driver, 120).

The scan driver 106 sequentially drives the scan lines SL of the display panel 100 in response to a scan control signal from the timing controller 120. The scan driver 106 supplies a scan pulse in a high state for each scan period of each scan line SL and a scan pulse in a low state during the remaining period in which the scan line SL is driven.

The data driver 108 converts the digital data from the timing controller 120 into an analog data voltage in response to the data control signal DCS from the timing controller 120 so that data Line DL.

The timing controller 120 is connected to the data driver 120 using a plurality of synchronizing signals (i.e., a vertical synchronizing signal Vsync and a horizontal synchronizing signal Hsync) input from a host computer (not shown), a data enable signal, A data control signal DCS for controlling the driving timing of the scan driver 108 and a scan control signal SCS for controlling the driving timing of the scan driver 106 are generated. The timing controller 120 outputs the generated data control signal DCS and the scan control signal SCS to the data driver 108 and the scan driver 106, respectively. The data control signal DCS includes a source start pulse and a source sampling clock for controlling the latch of the data signal, a polarity control signal for controlling the polarity of the data signal, a source output enable signal for controlling the output period of the data signal, . The scan control signal SCS includes a scan start pulse and a scan shift clock for controlling scanning of a scan signal, and a scan output enable signal for controlling an output period of the scan signal. Further, the timing controller 120 processes the image data input from the host system (not shown) and supplies the processed image data to the data driver 108.

The display panel 100 displays an image through unit pixels arranged in a matrix form. The unit pixel is composed of red (R), green (G) and blue (B) subpixels SP or red (R), green (G), blue (B) . Each sub-pixel SP includes a pixel driving circuit and an organic light emitting element OLED, as shown in Fig.

The pixel driver circuit includes first and second switching transistors ST1 and ST2, a driving transistor DT, and a capacitor Cst. Here, the configuration of the pixel driving circuit is not limited to the structure of FIG. 2, and a pixel driving circuit of various configurations can be used.

The first switching transistor ST1 is turned on by the control of the first scan line SL1 to transfer the data voltage from the data line DL to the gate electrode of the driving transistor DT.

The second switching transistor ST2 is turned on by the control of the second scan line SL2 to transfer a reference voltage from the reference line RL to the source electrode of the driving transistor DT, (DT) to the reference line (RL). The first and second switching transistors ST1 and ST2 may be controlled by different scan lines SL1 and SL2 or may be controlled by the same scan line.

The driving transistor DT is switched in accordance with the data signal supplied from the first switching transistor ST1 to control the current flowing from the high potential supply line PL to the organic light emitting element OLED.

The storage capacitor Cst is connected between the scan terminal of the drive transistor DT and the low potential voltage supply line VSS to charge the difference voltage therebetween and supply the drive voltage to the drive transistor DT.

The organic light emitting diode OLED is electrically connected between the source terminal of the driving transistor DT and the low potential voltage supply line VSS and emits light by a current corresponding to the data signal supplied from the driving transistor DT. To this end, the organic light emitting device OLED includes an anode electrode connected to the source terminal of the driving transistor DT, an organic layer formed on the anode electrode, and a cathode electrode formed on the organic layer. Here, the organic layer may include a hole injection layer / a hole transporting layer / a light emitting layer / an electron transporting layer / an electron injection layer.

Each of the red (R), green (G), blue (B) and white (W) subpixels SP is switched from the high potential power supply VDD And controls the magnitude of a current flowing to the organic light emitting device OLED to emit light in the light emitting layer of the organic light emitting device OLED to display a predetermined color.

In particular, in order to achieve the optimum luminance for each color, it is necessary to secure a proper aperture ratio for each sub-pixel SP. Here, the aperture ratio is a ratio occupied by the light emitting region in each sub-pixel SP, and the lifetime of the organic light emitting element can be improved by optimizing the aperture ratio.

For example, in order to improve the overall luminance of the organic light emitting diode display device, the white (W) sub-pixel SP is formed to have the largest light emitting area than the other sub-pixels SP, The green G subpixel SP is formed to be larger than the red subpixel SP and the green subpixel SP is formed to be larger than the red subpixel SP and the blue subpixel SP is formed to be larger than the red subpixel SP, The light emitting region is formed to be the smallest. Therefore, the aperture ratio is set higher in the order of the white (W) sub-pixel SP, the blue (B) sub-pixel SP, the red (R) sub-pixel SP and the green (G) sub-pixel SP.

In this case, if the aperture ratio is derived for each sub-pixel only considering the optimal luminance average for each color, deterioration of a specific sub-pixel at a specific position of the display panel 100 is biased according to an image implemented on the display panel 100 And a color afterimage is generated. For example, in a region where a stereoscopic image such as a caption and a logo is implemented, the deterioration of the white (W) sub-pixel SP is biased relative to the other sub-pixels SP, resulting in a white afterimage. In the region where the main image is mainly implemented, the deterioration of the red (R) subpixel SP is biased relative to the other subpixels SP, and a red afterimage is generated.

Therefore, in the present invention, the display panel 100 is divided into a plurality of display areas, and the degree of deterioration of the red (R), green (G), blue (B) (R), green (G), blue (B), and white (W) sub-pixels are optimized by considering the average of the luminance of each sub-pixel.

3, the display panel 100 is divided into outer display areas BA (BA1 to BA5) and main display areas MA (MA1 to MA4). The outer display area BA corresponds to the upper left BA1 and upper right BA2 and the lower areas BA3, BA4 and BA5 in the entire screen. The main display area MA is a central area corresponding to the remaining area of the outer display area, and a main image is implemented.

In the outer display area BA, the stereoscopic image is implemented at a fixed position for a long time by using white-based image data. Here, the stereoscopic image includes a logo, date information, time information, weather information, channel information, content related information, broadcast program related information, and subtitles. As a result, the frequency of use of the white (W) sub-pixel SP in the outer display area BA is larger than that of the other sub-pixels SP, Is severe. 4, the light emitting area EA of the white (W) sub-pixel arranged in the outer display area BA is divided into the white (W) sub-pixel SP) than the light-emitting region EA. The light emitting area EA of the white (W) sub pixel arranged in the outer display area BA is divided into red (R), green (G) and blue (B) sub pixels SP are formed larger than the respective light emitting regions EA.

Thus, in the present invention, the light-emitting area of the white (W) sub-pixel SP disposed in the outer display area BA is formed wider than the white (W) sub-pixel SP of the main display area MA. Accordingly, in the present invention, since the deterioration speed of the white (W) sub-pixel SP disposed in the outer display area BA is reduced, the time during which the white afterimage is generated in the outer display area BA is 2.5 times And the lifetime of the white (W) subpixel SP in the outer display area BA becomes equal to that of the other subpixels.

In the main display area MA, the red (R), green (G), and blue (B) sub pixels SP are used more frequently than the white (W) sub pixels SP. Particularly, in the main display area MA, a moving image such as a human face is frequently implemented. Therefore, in the main display area MA, the use frequency of the red (R) subpixel SP is relatively large, The deterioration of the sub-pixel SP is severe. In this case, a red afterimage is generated in the main display area MA, and the lifetime of the red (R) subpixel SP is shorter than that of the other subpixels SP. 4, the light emitting region EA of the red (R) sub-pixel SP disposed in the main display region MA is divided into the red (R) sub-pixel (SP). Particularly, in the main display areas MA1 and MA3 located at the center of the display panel 100, human faces and the like are often implemented more than the remaining main display areas MA2 and MA4. Accordingly, the light emitting area EA of the red sub-pixels of the main display areas MA1 and MA3 located at the center is formed larger than the remaining main display areas MA2 and MA4. In this case, red (R), white (W), blue (B), and green (G) subpixels (SP) are arranged in the main display areas MA1 and MA3 located at the center of the display panel 100 . In the main display areas MA2 and MA4 except for the main display areas MA1 and MA3 located at the center of the display panel 100, white (W), red (R), blue (B) ) Sub-pixel (SP).

As described above, in the present invention, the light emitting area of the red (R) subpixel SP disposed in the main display area MA is formed wider than the red (R) subpixel SP of the outer display area BA. Accordingly, in the present invention, since the deterioration rate of the red (R) subpixel SP disposed in the main display area MA is reduced, the time during which the red afterimage occurs in the main display area MA is reduced by 2.5 times So that the lifetime of the red (R) subpixel SP in the main display area MA becomes equal to that of the other subpixels.

FIGS. 5A and 5B are plan views illustrating the respective sub-pixels of the organic light emitting display shown in FIG.

The organic light emitting display shown in FIGS. 5A and 5B includes a plurality of unit pixels including red (R), green (G), blue (B), and white (W) subpixels SP.

Each of the red (R), green (G), blue (B) and white (W) subpixels SP includes first and second switching transistors ST1 and ST2 arranged in the non- (DT) and a storage capacitor (Cst), and an OLED disposed in the light emitting region (EA). At this time, the non-emission area of each sub-pixel SP is the same, but the emission area is set differently depending on the position of each sub-pixel SP.

Data lines DLR and DLW for supplying the red data voltage and the white data voltage are arranged between the red (R) and white (W) subpixels SP, A reference voltage line RL for supplying a reference voltage Vref is disposed between the green and blue sub pixels SPG and SPB and a green data voltage and a blue data voltage are provided between the green and blue sub pixels SPG and SPB. And a high potential voltage line PL for supplying a high potential voltage VDD is arranged between the green (G) and red (R) sub pixel areas SP.

At this time, the light emitting area EA of the white (W) sub pixel arranged in the outer display area BA is divided into red (R), green (G) and blue (B) Emitting region EA. To this end, the horizontal spacing distance between the data line DLW and the reference line RL for supplying the white data voltage spaced with the white (W) sub-pixel SP between the remaining signal lines Is larger than the horizontal separation distance. Accordingly, the width LW of the white (W) sub-pixel SP is longer than the width LR, LG, and LB of the remaining sub-pixels SP, can do. The width LB of the blue sub-pixel SP whose lifetime is relatively shorter than that of the red (R) and green (G) sub-pixels SP is smaller than that of the red (R) And the width LG of the green (G) sub-pixel SP is set to be smaller than that of the other sub-pixels SP in order to match the color temperature. Therefore, in the outer display area BA, the light emitting area is broadened in the order of white (W), blue (B), red (R) and green (G) subpixels (SP).

The light emitting area EA of the red (R) sub pixel (SP) arranged in the main display areas MA1 and MA3 disposed at the center of the main display area MA, Emitting region EA of each of the white (W), green (G) and blue (B) sub- To this end, the horizontal spacing distance between the data line DLR and the power supply line PL for supplying the red data voltage spaced apart by the red (W) sub-pixel SP is set to the remaining signal line Is larger than the horizontal separation distance. Accordingly, the width LR of the red (R) sub-pixel SP is longer than the width LW, LB, and LG of the remaining sub-pixels SP, can do. In order to improve the overall luminance of the main display region disposed at the center portion, the width of the white W sub-pixel SP is set larger than the width of the blue sub-pixel SP and the green sub- And the width of the blue sub-pixel SP having a shorter life span as compared with the green (G) sub-pixel SP is set larger than the green (G) sub-pixel SP, The width of the pixel SP is made smaller than that of the other sub-pixels SP. Therefore, in the main display areas MA1 and MA3 arranged at the center, the light emitting area is widened in the order of red (R), white (W), blue (B), and green (G) subpixels (SP). In the main display areas MA2 and MA4 in which the human face is implemented more frequently than the center part of the main display area MA, white (W), red (R), blue (B) (SP).

Meanwhile, in the present invention, for example, a structure in which the data line DL, the reference line RL, and the power source line PL are extended in the longitudinal direction and the area of the light emitting region EA of each sub pixel SP is set is exemplified The scan lines SL1 and SL2 extending in the horizontal direction are bent to set the light emitting area of the light emitting area EA of each sub pixel SP and the data line DL extending in the vertical direction, The scan lines SL1 and SL2 extending in the horizontal direction and the power supply line PL may be bent to set the light emitting area of each sub-pixel SP.

Meanwhile, in the present invention, a structure in which a stereoscopic image such as a caption and a logo is implemented is disposed on the outer periphery of the display panel. However, the stereoscopic image may be implemented in the main display area. In this case, the light emitting area of the red sub-pixel of the main display area in which the stereoscopic image is implemented is formed wider than the red sub-pixel of the display area in which the stereoscopic image is not realized.

Also, in the present invention, the red after-image and the after-after-image are described as an example. However, green and blue after-images may also be generated depending on the image displayed on the display panel. In this case, the image to be implemented in the display panel may be divided and analyzed according to the positions in the display panel, and then the optimum opening of each sub-pixel may be designed for each position at the time of manufacturing the display panel. Since the brightness of the OLED element of each sub-pixel depends on the amount of current, the driving voltage for each position (for example, a differential design of at least one of a data voltage and a scan voltage is unnecessary).

The foregoing description is merely illustrative of the present invention, and various modifications may be made by those skilled in the art without departing from the spirit of the present invention. Accordingly, the embodiments disclosed in the specification of the present invention are not intended to limit the present invention. The scope of the present invention should be construed according to the following claims, and all the techniques within the scope of equivalents should be construed as being included in the scope of the present invention.

100: display panel 106: scan driver
108: Data driver 120: Timing controller

Claims (6)

A plurality of display areas;
And a plurality of sub-pixels arranged in the display region and implementing different colors,
Wherein at least one of the plurality of sub-pixels has a light-emitting area according to a position of the display area. The method according to claim 1,
The plurality of display areas
At least one outer display area in which a still image is continuously displayed for a predetermined period of time;
And at least one main display area which is a display area other than the outer display area,
Wherein the plurality of sub-pixels are red, green, blue, and white sub-pixels. 3. The method of claim 2,
And the light emitting area of the white sub-pixel disposed in the outer display area is larger than the light emitting area of the white sub-pixel disposed in the main display area. The method of claim 3,
And the light emitting area is broadened in the order of the white, blue, red and green sub-pixels in the outer display area. 4. The method according to any one of claims 2 to 3,
And the light emitting area of the red sub-pixel disposed in the main display area is larger than the light emitting area of the red sub-pixel disposed in the sub-display area. 6. The method of claim 5,
Wherein a light emitting area of each of the red, white, blue, and green subpixels increases in the main display region of at least one of the plurality of main display regions,
And a light emitting area is broadened in the order of white, red, blue, and green subpixels in the remaining main display region among the plurality of main display regions.

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