KR20020027930A - EL Display using a plastic substrate - Google Patents

Abstract

The present invention relates to an organic light emitting display device using a plastic substrate, comprising: an anode electrode on an upper surface of a base substrate including a circular polarizing plate that blocks reflected light and a protective sheet that protects the circular polarizing plate; An organic light emitting device including a cathode is formed.

Then, the contrast is improved because the circularly polarizing plate blocks the reflected light reflected from the cathode electrode, and since the glass substrate and the circularly polarizing plate are not doubled, the organic light emitting diode display can be reduced in thickness and manufacturing cost can be reduced.

In addition, the base substrate is a plastic-based material is not damaged by shock or vibration can improve the reliability of the product.

Description

Organic light emitting display device using a plastic substrate {EL Display using a plastic substrate}

The present invention relates to an organic light emitting display using a plastic substrate. More particularly, the present invention relates to a top surface of a circular polarizing plate using a circular polarizing plate installed on a surface of a base substrate as a base substrate in order to improve contrast of the organic light emitting display. By forming an organic light emitting device, the present invention relates to an organic light emitting display using a plastic substrate for improving durability of a product and reducing manufacturing cost.

CRT (Cathode Ray Tube), one of the commonly used display devices, is mainly used for monitors such as TVs, measuring devices, and information terminal devices.However, due to the weight and size of the CRT itself, Could not respond actively to the demand.

In order to replace the CRT, flat panel displays having advantages such as light weight, short size, and low power consumption are being actively developed, and demand thereof is continuously increasing. Until now, the demand for liquid crystal display devices for displaying information using the electro-optical properties of liquid crystals among flat panel display devices has been the highest, and technology development has been focused on liquid crystal display devices.

However, since the LCD is a light-receiving device that displays an image by controlling the amount of light coming from the outside, its driving is complicated and a separate light source for illuminating the liquid crystal panel, i.e., a backlight assembly, is necessary. There are many disadvantages in various aspects, such as light and small size and price competitiveness of the liquid crystal display device.

As a result, an organic light emitting display, which is a self-luminous device that has a fast response speed, excellent luminance, and a simple structure, is advantageous in terms of price competitiveness and can be easily and lightly shortened, compared to a liquid crystal display device, which is a light-receiving element. Development of the device is actively underway. The organic light emitting device is attracting attention as a next-generation flat panel display device following the liquid crystal display device because of its various uses such as a backlight of a liquid crystal display device, a portable terminal, an automobile navigation system, a laptop computer, and a wall-mounted TV.

The organic light emitting diode display is formed of an organic light emitting part that emits light by itself between an anode electrode to which positive power is applied and a cathode electrode to which negative power is applied, and the organic light emitting diodes are formed from holes and cathode electrodes transferred from the anode electrode to the organic light emitting part. The electrons transferred to the negative side recombine to emit light.

The structure of the organic light emitting diode display will be briefly described as follows.

First, anode electrodes to which positive power is applied are formed on a screen display area, which is a part where a screen is displayed by depositing ITO metal on a base substrate, for example, an organic substrate that transmits light, and patterning the ITO metal. The outer side of is electrically connected with the drive to form leads for supplying positive or negative power to the anode electrode and the cathode electrodes to be formed in a subsequent process.

Thereafter, the photoresist is thickly coated, the photoresist is photo-developed to form partitions having high heights intersecting the anode electrodes at predetermined portions of the display area, and then the barrier ribs are deposited by depositing an organic material having a predetermined color. An organic light emitting part for emitting light by the flow of current is formed therebetween.

Subsequently, the cathode forming metal, that is, aluminum is deposited on the upper surface of the organic light emitting part, thereby forming cathode electrodes intersecting the anode electrodes between the partition walls.

In the case of the organic light emitting diode display having the above-described configuration, since the light flowing into the organic light emitting diode from the outside through the glass substrate is reflected by the cathode electrode formed of a metal such as aluminum and returned to the organic substrate, the contrast of the organic light emitting diode display is reduced. do. This is more serious when a black screen is displayed on the OLED display.

Therefore, in recent years, in order to prevent the contrast of an organic light emitting display from degrading by reflected light, the circularly-polarizing plate which blocks reflected light is used on the surface of the glass substrate on which a screen is displayed. Therefore, the manufacturing cost of the organic light emitting diode display is increased.

In addition, in the case of the glass substrate on which the organic light emitting element is formed, since the impact is easily broken by the impact or vibration applied from the outside, a problem occurs that the reliability of the product is lowered.

In addition, due to the thickness of the glass substrate and the thickness of the circularly-flat plate attached to the surface of the glass substrate, it is difficult to reduce the thickness of the organic light emitting display device.

Accordingly, an object of the present invention is to use a plastic having a thin thickness and strong impact as a base substrate of an organic light emitting display device.

Other objects of the present invention will become more apparent from the following detailed description and the accompanying drawings.

1 is a cross-sectional view schematically illustrating a structure of an organic light emitting diode display according to the present invention.

FIG. 2 is an enlarged view illustrating a main part of the enlarged portion A of FIG. 1 and illustrates a structure of a base substrate according to an embodiment.

3 is a cross-sectional view showing the structure of a base substrate according to another embodiment.

In order to achieve the above object, the present invention is composed of a circular polarizing plate and a reflective sheet, the organic material including an anode electrode, an organic light emitting part and a cathode electrode to generate light by the flow of current on the upper surface of the base substrate to block the reflected light A light emitting element is formed.

Preferably, the circularly polarizing plate is a polarizing plate for selectively passing only the light vibrating in an arbitrary direction, and the circularly polarized light so as to rotate in a predetermined direction of light in any direction passing through the polarizing plate When composed of plates, the protective sheet is attached to the surface of the polarizing plate Each sheet is attached to the surface of the plate to protect them.

Hereinafter, a structure and a manufacturing method of an organic light emitting diode display according to the present invention will be described with reference to FIGS. 1 to 3.

Hereinafter, a structure and a manufacturing method of an organic light emitting diode display according to the present invention will be described with reference to FIGS. 4 through 7.

As shown in FIG. 1, the organic light emitting diode display 100 includes an anode 210, an organic light emitting unit 220, and a cathode electrode 230 to display information, and an organic light emitting diode. The device 200 is formed and includes a base substrate 110 that improves contrast by blocking reflected light reflected from the cathode electrode 230.

As shown in FIG. 1, the base substrate 110 includes a circular polarizing plate 120 and protective sheets 150 and 152.

As shown in FIG. 2, the circularly polarizing plate 120 according to an exemplary embodiment may be attached to a polarizing plate 122 that selectively passes only light traveling in a 방향 or y direction, and attached to an upper surface of the polarizing plate 122. ) Or circularly polarized light to rotate in a predetermined direction, or change the circularly polarized light into light vibrating in the y or y direction It consists of a plate 124. In addition, the protective sheets 150 and 152 may be formed on the surface of the polarizing plate 122. Each sheet is attached to the surface of the plate 124 to protect them.

As shown in FIG. 3, the circularly polarizing plate 120 according to another embodiment has one protective sheet 150 and 152 attached to each of the upper and lower surfaces of the polarizing plate 122 and the upper surface of the protective sheet 152. on The plate 124 is installed and formed.

Referring to the process of forming the organic light emitting device on the upper surface of the circular polarizing plate configured as described above is as follows.

First, a transparent metal that transmits light to the upper surface of the base substrate 110, for example, ITO metal, is deposited at a low temperature at a temperature at which the base substrate 110 of the plastic system is not deformed, and then photolithography and etching techniques are performed. To pattern the ITO metal. Then, the anode electrodes 210 are formed in a stripe shape along the longitudinal direction of the base substrate 110 in the screen display area of the upper surface of the base substrate 110 by being spaced apart from each other by a predetermined distance, and the anode outside the screen display area. Leads 240 supplying power to the anode electrodes 210 and each of the electrodes to be formed in a subsequent process are formed in one row at one end in the longitudinal direction of the electrodes 210 and at one side in the width direction of the anode electrode 210. .

When the ITO metal is patterned as described above, after the photoresist is thickly coated on the upper surface of the base substrate 110 on which the anode electrodes 210 are formed, the photoresist is exposed and anisotropically etched to clean the organic light emitting part to be formed in a subsequent process. Partition walls 250 are formed to separate and prevent the cathode electrodes from shorting. Here, the barrier rib 250 crosses the anode electrodes 210 on the same line as the space between the leads 240 formed on one side of the anode electrode 210 in the width direction of the screen display areas of the base substrate 110. The strip is formed long in shape.

When the partitions 250 are formed in the screen display area of the base substrate 110, the shadow mask is positioned on the top surfaces of the partitions 250 and the upper portions of the anode electrodes 210 exposed between the partitions 250. Since organic materials for generating red, green, and blue light are sequentially deposited on the surface, the organic light emitting part 220 for generating red, green, and blue light is formed by the flow of current.

When the organic light emitting parts 220 are formed on the anode electrodes 210 positioned between the partition walls 250, the anodes are formed between the partition walls 250 by depositing aluminum on the upper surface of the base substrate 110 at a low temperature. The cathode electrodes 230 intersecting with the electrodes 210 are formed in a stripe shape.

When the organic light emitting diode display 100 is driven as described above, holes are transmitted from the anode electrode 210 to the organic light emitting unit 220, and electrons are transferred from the cathode electrode 230 to the organic light emitting unit 220. Then, the organic light emitting unit 220 recombines the electrons to emit red, green, and blue light having a predetermined brightness, and the red, green, and blue light are merged into one while passing through the base substrate 110, and thus, light of a predetermined color. Therefore, a desired image is displayed on the surface of the base substrate 110.

Meanwhile, while the organic light emitting diode display 100 is driven, light is introduced into the organic light emitting diode 200 from the outside through the base substrate 110, and the light is emitted from the cathode electrodes 230 formed of aluminum. Reflected back to the base substrate 110. When the reflected light passes through the base substrate 110 and comes out again, contrast decreases.

However, in the present invention, the reflected light is blocked by the circularly polarizing plate 120 constituting the base substrate 110.

When the circularly polarizing plate 120 blocks the reflected light in more detail, the light traveling in one of the external light traveling in the y or y directions is introduced into the polarizing plate 122.

For example, when the light traveling in the ｘ direction passes through the polarizer 122, the light passing through the polarizer 122 is The plate 124 changes the light to rotate clockwise.

The light which is turned into the light rotating in the clockwise direction is reflected from the cathode electrodes 230 formed of aluminum after passing through the anode electrode 210 and the organic light emitting unit 220, and thus, the organic light emitting unit 220 and the anode electrode 210. Through The plate 124 is reached.

Here, when light is reflected from the cathode electrode 230, the light rotating in the clockwise direction is changed to the light rotating in the counterclockwise direction.

Like this, the reflected light rotating counterclockwise Once the plate 124 is reached, The plate 124 changes this reflected light into light oscillating in the y direction. therefore, The reflected light changed into the light vibrating in the y direction at the plate 124 does not pass through the polarizing plate 122 passing only the light vibrating in the y direction, and thus the reflected light does not come back to the surface of the base substrate 110.

As described above, when the organic light emitting element is formed on the upper surface of the base substrate composed of the circular polarizing plate and the protective sheet, the contrast can be prevented from being lowered by the reflected light.

In addition, since the organic substrate and the circular polarizer are not used in duplicate, the organic light emitting diode display can be reduced in thickness and manufacturing cost can be reduced.

In addition, the base substrate is made of a plastic-based material and thus is not damaged by impact or vibration, thereby improving the reliability of the product.

Claims (3)

An organic light emitting device for displaying predetermined information and including anode electrodes, organic light emitting parts, and cathode electrodes; The organic light emitting device is formed on the upper surface, and the light generated by the organic light emitting device itself and transmits from the outside to reflect the reflected light reflected from the organic light emitting device comprises a plastic base base substrate An organic light emitting display using a plastic substrate. The method of claim 1, wherein the base substrate a polarizing plate for selectively passing only the light traveling in one of the light traveling in the ｘ and y directions; Installed on the upper surface of the polarizer to circularly polarize the light passing through the polarizer in a predetermined direction, and converts the light reflected from the cathode electrode into light vibrating in the opposite direction to the light transmitted from the polarizer; Plates and The polarizing plate and the Attached to the surface of the plate, respectively; An organic light emitting display using a plastic substrate, characterized in that consisting of protective sheets for protecting the plate. The method of claim 1, wherein the base substrate a polarizing plate for selectively passing only the light traveling in any one direction of light traveling in the y and y directions, Protective sheets respectively attached to upper and lower surfaces of the polarizer to protect the polarizer; Circularly polarized light so that the light passing through the polarizing plate rotates in a predetermined direction, and converts the light reflected from the cathode electrode into light vibrating in the opposite direction to the light transmitted from the polarizing plate An organic light emitting display using a plastic substrate, characterized in that consisting of a plate.