KR100712288B1 - flat panel display having image composed of low brightness pixel in a part of a display area and fabrication method of the same - Google Patents

Abstract

Provided is a flat panel display and a method of manufacturing the same. The flat panel display includes a pixel array in which a plurality of pixels are arranged. The reference luminance of some of the pixels of the pixel array is lower than the reference luminance of the remaining pixels. The low luminance pixels form a predetermined image.

Low brightness, deteriorated, organic light emitting display device

Description

Flat panel display having image composed of low brightness pixel in a part of a display area and fabrication method of the same}

1 is a diagram schematically illustrating a pixel array of an organic light emitting display device according to an exemplary embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of the pixel of FIG. 1.

3A is an enlarged view of some pixels in a deterioration process.

3B is a diagram illustrating a pixel array having low luminance pixels.

4 is a graph showing a change in relative luminance over time between a low luminance pixel and a normal pixel.

The present invention relates to a flat panel display, and more particularly, to a flat panel display having an image composed of low luminance pixels on a portion of a screen.

Flat panel displays have recently emerged as display devices replacing cathode-ray tube displays due to their light weight and thinness. Such flat panel displays include liquid crystal displays (LCDs), organic light emitting displays (OLEDs), plasma display panels (PDPs), and field emission displays; FED).

The flat panel display includes a pixel array including a plurality of pixels constituting a screen and a controller for applying an electrical signal to each pixel of the pixel array. The pixels display image information by an electrical signal applied from the controller, and thus an image is displayed on the screen.

On the other hand, as consumer preferences are diversified, some of the screens may require unique character display for each preference. However, flat panel display devices to date do not satisfy the needs of consumers.

SUMMARY OF THE INVENTION The present invention has been made in an effort to solve the above-described problems of the related art, and to provide a flat panel display device and a method of manufacturing the same, capable of displaying a special display according to a consumer's preference on a part of a screen.

In order to achieve the above technical problem, an embodiment of the present invention provides a flat panel display device. The flat panel display includes a pixel array in which a plurality of pixels are arranged. The reference luminance of some of the pixels of the pixel array is lower than the reference luminance of the remaining pixels. The low luminance pixels form a predetermined image.

The low luminance pixels may be degraded. In addition, the pixel may include an organic light emitting photodiode.

In order to achieve the above technical problem, another embodiment of the present invention provides a method of manufacturing a flat panel display device. The manufacturing method includes forming a pixel array in which a plurality of pixels are arranged on a substrate. Some pixels of the pixel array are degraded so that their reference luminance is lower than the reference luminance of the remaining pixels. The low luminance pixels form a predetermined image.

Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings in order to describe the present invention in more detail. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. In the figures, where a layer is said to be "on" another layer or substrate, it may be formed directly on the other layer or substrate, or a third layer may be interposed therebetween. Like numbers refer to like elements throughout the specification.

FIG. 1 is a schematic view of a pixel array of an organic light emitting display device according to an embodiment of the present invention, and FIG. 2 is an equivalent circuit diagram of the pixel shown in FIG. 1.

1 and 2, the organic light emitting display device includes a pixel array PA. The pixel array PA includes a plurality of pixels P. The pixels P are arranged in n rows and m columns. In detail, n scan lines SL1 to SLn and m data lines DL1 to DLm are arranged while crossing each other. The pixels P are positioned at intersections of the scan lines SL1 to SLn and the data lines DL1 to DLm, respectively.

Each pixel P includes a switching transistor M1, a capacitor Cst, a driving transistor M2, and an organic light emitting diode OLED. The switching transistor M1 has a gate connected to the scan line SL, a source connected to the data line DL, and applied to the data line DL by a scan signal applied to the scan line SL. Switched data signals. The capacitor Cst is connected between the drain of the switching thin film transistor M1 and the power line VDD to maintain the data signal for a predetermined period of time. The driving thin film transistor M2 has a gate connected to the capacitor Cst, a source connected to the power line VDD, a drain connected to the organic light emitting diode OLED, and a magnitude of the data signal. The voltage proportional to is supplied to the organic light emitting diode OLED.

The organic light emitting diode OLED includes an anode (not shown), a cathode (not shown), and an organic light emitting layer (not shown) interposed between the anode and the cathode. A voltage proportional to the magnitude of the data signal is supplied to the anode, and a reference voltage VSS is applied to the cathode. In this case, holes are injected from the anode into the organic light emitting layer, electrons are injected from the cathode into the organic light emitting layer, holes and electrons injected into the organic light emitting layer are combined in the organic light emitting layer to generate excitons. These excitons emit light as they transition from the excited state to the ground state.

The reference luminance of some pixels P _{LB of the} pixels P is lower than that of the other pixels. The low luminance pixels P _LB form a predetermined image on a screen. In the present specification, the reference luminance refers to the luminance when the voltage difference or current difference between the anode and the cathode is the same for all of the selected pixels. The low luminance pixels P _LB are used for excessive driving. It may be pixels degraded by.

Hereinafter, a method of manufacturing an organic light emitting display device according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2 again.

First, a pixel array PA in which a plurality of pixels P is arranged is formed.

Subsequently, some pixels P _LB of the pixel array PA are degraded such that their reference luminance is lower than the highest luminance of the remaining pixels.

_Degrading the some pixels P _LB may be performed by continuously driving the some pixels P _LB. However, in this case, since it takes a long time until the highest luminance of the some pixels P _LB is lowered, the voltage difference or the current difference between the anode and the cathode of the some pixels P _LB may be increased to shorten the time. have. As a result, the organic light emitting layers of the pixels P _LB may deteriorate to exhibit low reference luminance. Accordingly, when the entire pixel array PA is driven, the low luminance pixels P _LB continuously display lower luminance than the remaining pixels, and thus the low luminance pixels P _LB are displayed on the screen. It is possible to form a predetermined image.

3A is an enlarged view of some pixels in a deterioration process, and FIG. 3B is a view of a pixel array including low luminance pixels.

Referring to FIG. 3A, some pixels that may represent an image as illustrated in the pixel array are selected. Some of the pixels include a red pattern R made of red pixels, a green pattern G made of green pixels, a blue pattern B made of blue pixels, and a white pattern W. The white pattern W includes a red pixel, a green pixel, and a blue pixel.

By applying a data voltage to the data lines of the selected pixels, applying a power supply voltage to the power lines, and applying a reference voltage to the cathodes, driving the selected pixels until the reference luminance of the selected pixels is reduced. Deteriorate

Thereafter, as shown in FIG. 3B, only the blue pixels of the pixel array PA are driven. As a result, the blue pixels of the low luminance pixels P _LB that are degraded to exhibit a low reference luminance exhibit lower luminance than the other blue pixels to form a predetermined image on the screen.

4 is a graph showing a change in relative luminance over time between a low luminance pixel and a normal pixel.

Referring to FIG. 4, even in the normal pixel A that has not undergone the deterioration process, the relative luminance decreases as the driving time elapses. The relative luminance refers to the ratio of the reference luminance after a specific time elapses with respect to the initial reference luminance.

In addition, the relative luminance of the low luminance pixel B deteriorated to have an initial reference luminance of about 90% compared to the normal pixel A also decreases with time. However, the ratio between the luminance of the low luminance pixel B and the luminance of the normal pixel A may be substantially constant over time. Therefore, the low luminance pixel B has a lower luminance characteristic than a normal pixel when the pixel array implements a predetermined image, thereby forming an image on the screen.

As described above, according to the present invention, some pixels of the pixel array have a lower reference luminance than the other pixels, and the low luminance pixels form a predetermined image to form a flat display having a special display that matches a consumer's preference on a part of the screen. A device can be provided.

Claims (5)

A plurality of pixels are arranged, the reference luminance of some of the pixels is lower than the reference luminance of the remaining pixels, the low luminance pixels include a pixel array for forming a predetermined image. The method of claim 1, And the low luminance pixels are degraded. The method of claim 1, And the pixel includes an organic light emitting diode. Forming a pixel array in which a plurality of pixels are arranged on a substrate, And deteriorating some pixels of the pixel array such that a reference luminance thereof is lower than a reference luminance of the remaining pixels, wherein the low luminance pixels form a predetermined image. The method of claim 4, wherein And the pixel comprises an organic light emitting diode having an anode, a cathode, and an organic light emitting layer interposed between the anode and the cathode.

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