KR19990073222A - Multicolor paper-like Display fabricated by ink-jet method - Google Patents

Abstract

The present invention relates to the manufacture of flat panel displays in the form of paper, and more particularly, to a plastic substrate in an ink-jet form after dissolving a luminescent organic substance and an organic substance which facilitates electron transfer and an organic substance that facilitates hole movement into a solution. It relates to a technique for producing a paper-like display by forming a light emitting layer by spraying on

To this end, the present invention, the step of etching the indium-tin oxide electrode coated on a transparent plastic, such as polyethylene terephthalate (PET), the desired pattern to form a light emitting region on the electrode plate Forming an inkjet method, forming an organic material and an upper electrode on the plate on which the ink is formed, and then sealing the multilayer film structure by using an epoxy resin or the like on the entire surface after the step. have.

Description

Multicolor paper-like display fabricated by ink-jet method

The present invention relates to the manufacture of flat panel displays in the form of paper, and more particularly, to a plastic substrate in an ink-jet form after dissolving a luminescent organic substance and an organic substance which facilitates electron transfer and an organic substance that facilitates hole movement into a solution. The present invention relates to a technique for manufacturing a paper-like display by forming a light emitting layer by spraying on the same.

In general, information displays until recently were limited to the area of cathode ray tube (CRT) univariate, but with the development of the information society, the amount of information that humans can access and the types of information that humans can access become diverse. Therefore, a new concept display is required. For example, in the case of a device used in an environment where mobility is emphasized such as personal handheld or a car or an aircraft, light and small weight and low power consumption are important factors, and when used as an information transmission medium for the public, the viewing angle is wide and the luminance is high. High display characteristics of the large screen is required. In other words, the answer to "what type of display is suitable for a user's specific needs and how to develop such a display?" Has been developed over the last decade and the development of a flat panel display (FPD).

Representative technologies for flat panel display (FPD) include liquid crystal display (LCD), plasma display panel (PDP), field emitter display (FED), and electroluminescent display (ELD). ), A digital mirror display (DMD), and the like. Each of these displays has its own advantages as well as its disadvantages, which are advantageous depending on the application. Currently, liquid crystal displays, which account for more than 30% of all information display products and are rapidly replacing cathode ray tubes, are often restricted in terms of operating temperature, viewing angle, and screen size. It is known that the field emission display or plasma display panel still needs to be much lowered in price for commercialization, and there are technical problems to be solved. Ultimately, the most important factor in the successful development of future displays is the low rate of cost / performance and applicability.

In the present invention, various processes to considerably lower the price of the display and maximize the applicability have been considered. The research on the organic electroluminescent display to which the present invention is directed was conducted in Japan and the United States after Dr. Tang and VanSlyke of Eastman Kodak announced the fabrication of innovative devices through the implementation of multilayer light emitting films using sublimation in vacuum. It became full-scale. However, its commercialization is delayed due to its short lifespan, difficulty in the process of pattern formation, and low luminous efficiency. The recently developed conductive polymer electroluminescent displays exhibit luminous efficiency comparable to that of conventional inorganic semiconductor electroluminescent displays, and can be made inexpensive, simple in manufacturing process, large in area and flexible in display. It is known that its potential as a next-generation display is very high.

There are many technical problems to be solved prior to the commercialization of organic electroluminescent display. Firstly, the interface characteristics between each layer existing inside the device and the lifetime of the device accordingly, and secondly, It is required to improve deterioration characteristics through securing stability and developing surface stabilization technology. However, above all, the development of a light emitting layer forming technology and a process that can prevent the oxidation and deterioration of organic materials used in the light emitting layer is a problem that must be solved for smooth commercialization. For example, in FIG. 1, the most commonly used vacuum deposition process is used to form the light emitting layer, and then the pixel is formed by patterning the light emitting layer based on a photolithography process in order to realize a natural color. Due to this, there is a problem in that the life of the device can be reduced because it is inevitable to be deteriorated, and there is a problem that the overall process cost is very high.

The present invention is to solve the above problems by dissolving the organic light emitting material in a suitable solvent to make an ink, and then to reproduce the shape of the desired shape by inkjet spraying method on a thin plastic, it is possible to fundamentally modify the organic matter that can occur during photo-etching It is an object of the present invention to provide a method that can be prevented and can be reproduced as a light-emitting image that is already designed by a user and stored in a computer. It is also an object of the present invention to produce a color paper display, more specifically, a paper lamp, which can be applied to a toy for children because of its flexibility and stability in handling because it is not broken like glass.

In order to achieve the above object, the present invention provides a method for etching an indium-tin oxide (ITO) electrode coated on a transparent plastic such as polyethylene terephthalate (PET), and forming a desired pattern to form a light emitting region on the electrode plate. Forming by the inkjet method, as shown in Figure 2, forming the organic material and the upper electrode on the plate on which the ink is formed, the sealing step for protecting the multilayer film structure using an epoxy resin or the like on the entire surface after the step It is characterized by consisting of.

1 is a structure of a generally used organic electroluminescent display

2 is a block diagram of a device used to form a light emitting layer in the structure of a paper display;

3A is a sectional view of a monochromatic paper display obtained in Example 1

3B is a sectional view of the colored paper display obtained from Example 2;

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

Example 1 Paper Display Manufacturing Method

The color paper display of the present invention is manufactured through the following steps.

① The solution injected through the inkjet head is a material that can easily supply holes to the light emitting layer. More specifically, chloroform or 1,2-dichloroethane is dissolved in a solvent mixed with isoprophylalcohol in an appropriate ratio to form holes for the same layer of ink.

② Fill the ink solution thus prepared into the cartridge of the inkjet printer.

③ After washing the plastic substrate coated with ITO, put it in the inkjet printer connected to the computer, and connect the desired shape already input to the computer to the printer filled with the ink made in ① to form a hole transport layer as shown in FIG. 3A. .

(4) A light emitting organic substance is applied to the plastic substrate as shown in Fig. 3A. At this time, the luminescent material that can be used is commercialized, more specifically, PPV-based polymer material such as poly (2-methoxy-5-2-ethy-hexyloxy) -1,4-phenylene-inylene (MEM-PPV) The coating method is applied and low molecular weight organic materials such as DCM2, Quinacridone and DPVBi are vacuum deposited together with tris (8-hydroxy qunolinate) aluminum (Alq).

⑤ The upper electrode is formed by depositing LiAl / Al or MgAg / Mg metal having a low work function for easy electron entry into the light emitting layer.

⑥ A final display is obtained by laminating and sealing the plastic plate on which the upper electrode is completed with another plastic plate. In this case, the light emitting area is limited to an area in which the hole transport layer is located.

Example 2

① There are four inkjet cartridges used in commercial printers. A cartridge using black ink is used as a black matrix and is filled with a polymer that can act as an inter-pixel insulation, and more specifically, an insulating polymer such as polyimide is dissolved in a solvent to fill the ink. The red ink is mixed with polyvinylcarbazol (PVK), 2,5-bis (1,2-naphtyl) -1,3,4-oxadiazol (BND), which can facilitate electron transfer, and dye Nile red. Make and fill the ink in the same way as Use the same method as above for green ink and blue ink, but use green dye Coumarin 6 or Coumarin 540 instead of Nile red and blue dye 1,1,4,4-Tetaphenyl-1,3-butadiene or courmarin 47 do.

② Install the ink for the black matrix in the printer or the solution spraying device. Instead of the red, green, and blue ink, install the luminous solutions prepared in ①.

③ Print the image as it is input to the computer.

④ Form the upper electrode and then suture to manufacture the display. In this case, when electricity is applied to the electrode, the printed solution emits a unique color in proportion, thereby displaying various information.

As described above, the present invention is a method of forming an ink by dissolving a light emitting organic material on a plastic substrate and then forming a pattern by an inkjet spraying method. It can be used as an instrument to display information. In particular, it is unbreakable and can be applied over a very wide range of applications.

Claims (5)

Paper display patterned with information or shape based on inkjet method on PET coated with transparent electrode The method of claim 1, wherein the hole transport layer organic material is patterned. The method of claim 1, wherein the inkjet cartridge is filled with a pattern of ink used as a black matrix. The method of claim 1, wherein the red, green, and blue inks are filled and sprayed onto the ITO. The method of claim 1, wherein the plastic is laminated and sealed.