KR101207407B1 - OLED having high-definition - Google Patents

Abstract

The present invention relates to an organic light emitting device, and more particularly to a support substrate; An organic light emitting unit formed on one surface of the support substrate and including an organic light emitting layer between a pair of electrodes; An encapsulation substrate positioned above the organic light emitting part; And an encapsulant that couples the support substrate and the encapsulation substrate, and provides an organic electroluminescent device having a high quality including a dot-type film having an embossed or engraved dot shape on an outer surface of the encapsulation substrate.

Description

Organic electroluminescent device having high picture quality {OLED having high-definition}

The present invention relates to an organic electroluminescent device, and more particularly, to an organic electroluminescent device having high image quality by increasing the contrast ratio.

In the organic light emitting device, the organic light emitting unit is generally injected by injecting electrons and holes into the light emitting layer from the electron injection electrode and the hole injection electrode, respectively. It is a device that emits light when an exciton in which electrons and holes are combined falls from an excited state to a ground state.

Due to this principle, unlike the conventional thin film liquid crystal display device, since a separate light source is not required, there is an advantage in that the volume and weight of the device can be reduced.

In addition, the organic EL device exhibits high quality panel characteristics (low power, high brightness, high reaction rate, low weight). OELD is considered to be a powerful next-generation display that can be applied to portable communication products such as mobile communication terminal, CNS (Car Navigation System), personal digital assistances (PDA), Palm PC, etc.

In general, the organic light emitting device is composed of a transparent support substrate and a sealing substrate spaced apart from each other, the support substrate and the sealing substrate is encapsulated with each other by a sealing material (encapsulation). An array portion including a plurality of thin film transistors, gates, data lines, and storage capacitors is formed on an upper portion of the support substrate. have. In this case, the organic layer expresses the colors of red (R), green (G), and blue (B), and in general, red (R), green (G), and blue (B) colors for each pixel. A separate organic material emitting light is used as a pattern.

Since the organic light emitting device (OLED) is a self-luminous type, the viewing angle is wider than the LCD, the contrast is good, and since the backlight is not required, the organic light emitting device (OLED) can be reduced in weight and advantageous in terms of power consumption. In addition, it is easy to display video because it has a sensitive screen and quick response time compared to other displays, and unlike LCD, it is attracting attention as a next-generation display because it is composed of solid thin film, which is strong in vibration and has a relatively wide use temperature range.

Various methods have been sought for the organic EL device to have a clear picture quality, but the clear contrast ratio is an important factor in order to have a clear picture quality. Contrast Ratio can be defined as "(brightness of white light + brightness of reflected light) ÷ (brightness of black light + brightness of reflected light), and the higher the clear contrast ratio, the clearer the image quality. The electrode layer of the light emitting part becomes visible, and thus a problem of poor image quality occurs.

Two related variables which the contrast ratio can improve can be improved by decreasing the reflectance and increasing the transmittance.

Conventionally, the organic light emitting device has included a λ / 4 film and a polarizing film on the display substrate visible to increase the contrast ratio. In this case, the clear contrast ratio is increased and the image quality is clear, but since the λ / 4 film and the polarizing film are expensive, the production cost is high and the transmittance is excessively suppressed due to the polarizing film. The problem caused by the unnecessary polarization of light, such as causing a non-uniformity of the image quality is raised.

Therefore, in order to solve such a problem, it is desired to develop an organic light emitting device capable of realizing clear image quality by increasing the contrast contrast ratio without using the λ / 4 film and the polarizing film, and reducing the production cost while improving the transmittance.

SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide an organic electroluminescent device capable of realizing a stereoscopic screen with a reduction in production costs, an improvement in brightness from a display device, and an improvement in contrast ratio. have.

Another object of the present invention is to provide an organic light emitting device which improves transmittance and does not cause polarization.

It is still another object of the present invention to provide an organic light emitting display device having high contrast and high contrast.

The present invention to achieve the above object is a support substrate; An organic light emitting unit formed on one surface of the support substrate and including an organic light emitting layer between a pair of electrodes; An encapsulation substrate positioned above the organic light emitting part; And an encapsulant that couples the support substrate and the encapsulation substrate, and provides an organic electroluminescent device having a high quality including a dot-type film having an embossed or engraved dot shape on an outer surface of the encapsulation substrate.

In another aspect, the present invention provides an organic electroluminescent device having a high picture quality, characterized in that the dot shape is a dark color to block external light, the occupancy area occupied by the dot shape is 30 to 40%.

In addition, the present invention is an organic having a high picture quality, characterized in that the portion of the surface of the dot-shaped film outside the dot shape is dark to block external light, the occupancy area occupied by the portion outside the dot shape is 30 to 40% An electroluminescent device is provided.

In addition, the dark color of the present invention provides an organic EL device having a high quality, characterized in that it comprises a light absorbing material.

In another aspect, the present invention provides an organic electroluminescent device having a high picture quality, characterized in that the light absorbing material comprises carbon black, black inorganic material, organic material or metal.

In another aspect, the present invention provides an organic electroluminescent device having a high picture quality, characterized in that the average diameter of the dot shape is 300nm ~ 100㎛.

In another aspect, the present invention provides an organic electroluminescent device characterized in that the coating is made on the outermost surface of the sealing substrate or the protective film is additionally included.

In another aspect, the present invention provides an organic electroluminescent device having a high image quality further comprises a planarization layer functioning as a buffer layer between the upper surface of the support substrate and the lower surface of the organic electroluminescent unit.

In another aspect, the present invention provides an organic electroluminescent device having a high picture quality, characterized in that the inner space partitioned by the support substrate and the sealing substrate is filled with an inert gas of nitrogen, neon or argon.

In another aspect, the present invention provides an organic electroluminescent device having a high-definition, characterized in that the organic electroluminescent unit is stacked between the electrode layer and the electrode layer, a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, an electron injection layer in order. .

The organic electroluminescent device according to the present invention does not use a polarizing film, thereby realizing a viewing angle characteristic suitable for improving luminance and configuring a stereoscopic screen, while reducing production cost.

In addition, the organic EL device according to the present invention has an effect of improving transmittance and not causing polarization.

In addition, the organic light emitting device according to the present invention has the effect that the contrast ratio is improved to display high quality.

1 is a cross-sectional view of an organic light emitting display device according to an embodiment of the present invention.
Figure 2 shows a perspective view of a dot-type film laminated on the outer surface of the organic light emitting device according to an embodiment of the present invention.
Figure 3 shows a perspective view of a dot-type film laminated on the outer surface of the organic light emitting device according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that, in the drawings, the same components or parts have the same reference numerals as much as possible. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

The terms " about ", " substantially ", etc. used to the extent that they are used herein are intended to be taken to mean an approximation to or in the numerical value of the manufacturing and material tolerances inherent in the meanings mentioned, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

1 is a cross-sectional view of an organic light emitting display device according to an embodiment of the present invention.

According to FIG. 1, the present invention provides an organic light emitting device that emits light toward a sealing substrate, and includes a support substrate 110, an organic light emitting unit 130 formed on one surface of the support substrate, that is, a support substrate, and the organic light emitting unit. And a sealing substrate 120 positioned on the supporting substrate 110 so as to block from the substrate. In addition, a dot-type film 140 is formed on the outer surface of the sealing substrate 120.

Conventional organic light emitting devices have been difficult to be used directly in various display devices in which high quality is an important factor due to the visible problem of the electrode layer of the organic light emitting part. Accordingly, the λ / 4 film and the polarizing film on the outer surface of the sealing substrate. By bonding to improve the visibility to provide a high-quality organic electroluminescent device. However, although there are advantages of high quality, it is difficult to implement a stereoscopic screen due to the high cost and polarizing film. The present inventors have completed the invention by including a dot film 140 so that high quality and stereoscopic screen can be realized while reducing production costs. .

The organic light emitting device according to the present invention serves to improve the contrast ratio. The contrast ratio is defined as "(luminance of white light + luminance of reflected light) ÷ (luminance of black light + luminance of reflected light). The greater the contrast ratio, the higher the quality of the organic light emitting device.

Two related variables that the clear contrast ratio improves can be improved due to the decrease in the reflectance and the increase in the transmittance. The present invention can be seen that the clear contrast ratio is improved by decreasing the reflectance.

Figure 2 shows a perspective view of a dot-type film laminated on the outer surface of the organic light emitting device according to an embodiment of the present invention.

The dot film 140 is preferably a circular dot shape of an embossed or engraved shape on the emission surface side of the film, but is not limited thereto, and may be a polygon other than a triangle and a quadrangle.

The dot shape has a function of shielding external light, and may have a dark color to absorb external light. For example, a light absorbing material may be included. The light absorbing material may generally use carbon black, but is not limited thereto, and may include black inorganic material, organic material, or metal.

The dot-shaped average diameter is preferably 300nm ~ 100㎛, it may be arranged irregularly. Moreover, it is preferable that the occupancy area rate which the said dot shape occupies is 50% or less, and it is more preferable that it is 30 to 40%. Since the dot-type film 140 is located on the outer surface of the support substrate, the reflectance of light entering the film from external light may be reduced, and thus the contrast ratio may be further improved.

Figure 3 shows a perspective view of a dot-type film laminated on the outer surface of the organic light emitting device according to another embodiment of the present invention.

Optionally, a portion of the surface of the dot-type film 140 may have a dark color on a portion other than the embossed or engraved dot shape to absorb external light. For example, a light absorbing material using carbon black may be included in a portion other than a dot shape, or a dark colored film may be stacked.

The average diameter of the dot shape is preferably an average diameter of the dot shape is 300nm ~ 100㎛, may be arranged irregularly. Moreover, it is preferable that it is 50% or less, and, as for the occupation area ratio which the part other than the said dot shape occupies, it is more preferable that it is 30 to 40%. Since the dot-type film 140 is located on the outer surface of the support substrate, the reflectance of light entering the film from external light may be reduced, and thus the contrast ratio may be further improved.

The dot film 140 is preferably a transparent resin film having ultraviolet ray permeability. As the material of the upper dot film 140, polyethylene terephthalate (PET), polycarbonate (PC), polyvinyl chloride (PVC), or the like may be used. .

In addition, the outer surface, that is, the outermost surface of the encapsulation substrate may be additionally coated or a protective film may be adhered to protect the dot film 140. Non-limiting examples of the coating may be made of a hard coating or antifouling coating. In addition, the refractive index of the coating or protective film is preferably smaller than the refractive index of the dot-type film 140.

Meanwhile, the support substrate and the sealing substrate 120 may be made of thin glass alone, or an optical film may be implemented as a support on one or both of the upper and lower surfaces of the upper or lower surfaces of the thin glass.

It is preferable that the thickness of the thin glass of the said support substrate and the said sealing substrate is 10-1000 micrometers. In the supporting substrate and the sealing substrate of the present invention, the support laminated on the thin glass is preferably a transparent optical film, and the optical film of the supporting substrate may be embodied on one or both of the upper and lower surfaces of the thin glass. have. By supporting the optical film as a support, the strength of the substrate is increased, so that the glass does not easily break even when the glass is subjected to an external impact. In addition, more than 90% of the glass is damaged at the corners during the process. By preserving the glass strength is preserved. On the other hand, since the dot film 140 is located on the upper surface of the sealing substrate, it is preferable that the support is formed only on the lower surface of the thin glass in the case of the sealing substrate.

With regard to the laminated glass, the glass is not only excellent in transparency but also a barrier layer, because the glass is excellent in hardness and chemically stable, has high heat resistance and resistance to reactive materials, and is excellent in transparency to light. It forms a barrier to block oxygen or moisture from the outside. In the case of high gas permeability such as oxygen or moisture through the substrate in relation to the barrier property, the material constituting the display element is affected by the transmitted oxygen or water, which shortens the lifespan and reduces the luminous efficiency. The quality of the product can depend on how good it is. As the thin glass is used as a flat panel display device, oxygen and water vapor permeability are measured, and as a result, excellent barrier properties and light transmittance can be obtained.

The optical film used for the supporting substrate 110 and the sealing substrate 120 of the present invention is polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycarbonate (PC), polyethylene sulfone (PES), transparent polyimide (PI) ), Polyarylate (PAR), polycyclic olefin (PCO), cross-linked epoxy, cross-linked urethane film may be used any one selected from the group consisting of.

In addition, the thin glass and the support of the supporting substrate 110 and the sealing substrate 120 may be formed of a support of the same material, and the thin glass is used in the same thickness.

As described above, the advantage of using the same thickness of the thin glass and using the support of the same material is that, first, since the support substrate 110 and the sealing substrate 120 are formed of the same material, the coefficient of thermal expansion of the support substrate 110 and the sealing substrate 120 is the same. It is possible to improve the mechanical strength of the panel against temperature changes. Second, by forming the sealing substrate 120 using a glass substrate, the panel can be thinner and lighter than in the case of employing the metal sealing substrate 120. Third, since the substrate using glass is higher in surface smoothness than the sealing substrate 120 made of metal or the like, a gap is hardly formed at the interface with the sealing material, and the adhesive force can be increased.

Therefore, oxygen, moisture, etc. are hard to penetrate from the outside, and sealing performance can be improved.

Meanwhile, the planarization layer 150 functioning as a buffer layer may be formed on the upper surface of the support substrate 110 according to an embodiment of the present invention. The planarization layer 150 may be obtained by partially hydrolyzing the composition for forming an organic or organic-inorganic hybrid layer to form a sol solution, and then coating and curing it on the support substrate 110, which is a transparent substrate. The coating method may be a method such as spin coating, roll coating, bar coating, dip coating, gravure coating, spray coating. The sol state curing method may be used, such as thermal curing, UV curing, infrared curing, high frequency heat treatment. The thickness after the flattening layer is cured is 0.1 µm to 50 µm, preferably 0.1 µm to 20 µm, and more preferably 0.1 µm to 10 µm. If the thickness is thinner than 0.1 μm, it is susceptible to failure due to pinhole defects, and suffers from a limitation in that leakage current occurs later. In addition, if the thickness exceeds 50 μm, cracks and surfaces may occur. There is a problem of uneven formation.

In the present invention, the planarization layer 150 functioning as a buffer layer is important in terms of surface flatness Ra (average of roughness). If the planarization layer 150 is not flat, defects occur when the connection electrode and the organic light emitting layer on the planarization layer are deposited. As a result, leakage current occurs, and thus the life of the organic light emitting part is limited. Accordingly, in the present invention, the flatness of the planarization layer 150 is preferably 0.5 nm to 5 nm, and more preferably 0.5 to 1 nm, based on the stylus method. In addition, the organic material having a roughness of about 5 nm to 50 nm or a root-mean-square roughness (RMS value) in the maximum peak-to-valley roughness in the present invention. It is desirable to provide an electroluminescent device. In this case, the luminance is increased at the same voltage, thereby improving the quality of the organic light emitting device.

Meanwhile, referring to the organic light emitting unit, the organic light emitting unit 130 is formed of an electrode layer and an organic layer, and the electrode layer 131 supplies a cathode electrode and a hole for supplying electrons. An organic light emitting layer 133 is disposed so that anode electrodes are disposed to face each other, and are disposed between these cathode electrodes and the anode electrode to emit light.

The electrode layer 131 may be formed of ITO, IZO, ZnO, or In ₂ O ₃ . The electrode layer 131 may be formed in a predetermined pattern.

In addition, the organic light emitting layer 133 disposed between the electrode layers 131 may be a low molecular or polymer organic layer. When the low molecular organic layer is used, a hole injection layer (HIL), a hole transport layer (HTL), and an organic layer may be used. An emission layer (EML), an electron injection layer (EIL), an electron injection layer (ETL) and the like may be formed by stacking a single or a composite structure, and the low molecular weight organic layer may be formed by vacuum deposition. It can be formed by the method.

In the case of the polymer organic layer, the structure may include a hole transporting layer (HTL) and a light emitting layer (EML). In this case, PEDOT is used as the hole transporting layer, and polyvinylvinylene (PPV) and polyfluorene (PPV) are used as the emitting layer. Polymer organic materials such as polyfluorene) may be used and may be formed by screen printing or inkjet printing.

In the organic light emitting unit 130, as anode and cathode voltages are applied to the anode electrode and the cathode electrode, holes injected from the anode electrode are moved to the light emitting layer, and electrons are injected from the cathode electrode to the light emitting layer. Electrons and holes recombine in to generate excitons, and as the excitons change from the excited state to the ground state, the fluorescent molecules in the light emitting layer emit light to form an image. The light emitting layer has a light emitting layer formed of a three-layer structure by sequentially stacking light emitting layers implementing red (R), green (G), and blue (B), or a light emitting layer having a complementary color relationship. It may be formed in a single layer structure consisting of a light emitting layer to implement.

In addition, the support substrate 110 and the sealing substrate 120 may be bonded through the sealing material 160. The encapsulant 160 bonds the support substrate 110 and the encapsulation substrate 120 through a thermosetting adhesive or a UV curable adhesive, and may be positioned along an edge of the encapsulation substrate 120. The encapsulant 160 forms an encapsulant 160 in a width of 0.1 to 2 mm at an edge portion of the encapsulation substrate 120 to bond the support substrate 110 including the organic light emitting unit 130 and the encapsulation substrate 120. The sealant 160 may be formed by printing using a screen mask or by applying a sealant dispense or a syringe directly to a corresponding position. In one embodiment of the present invention was provided using a Nagase (XNR 5570) product as a UV (Ultra violate) curing adhesive provided in a rectangular frame shape installed outside the light emitting area.

On the other hand, the inner space partitioned by the support substrate 110 and the sealing substrate 120 is preferably formed in a vacuum or to fill the inert gas. The inert gas is preferably filled with a gas such as nitrogen, neon or argon. In particular, when the inert gas is filled, it is in a state capable of adequately protecting the penetration of oxygen and moisture.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. It will be clear to those who have knowledge of.

Claims (10)

Support substrates; An organic light emitting unit formed on one surface of the support substrate and including an organic light emitting layer between a pair of electrodes; An encapsulation substrate positioned above the organic light emitting part; And a sealing material for coupling the supporting substrate and the sealing substrate, wherein the outer surface of the sealing substrate includes a dot-shaped film having a dot shape of an embossed or engraved shape,
The dot-shaped portion of the surface of the dot-shaped film is dark to block external light, the dark color is a light absorbing material containing any one of carbon black, black inorganic material, organic material or metal,
The area ratio occupied by the dot-shaped portion is 30 to 40%,
The dot-shaped average diameter of the organic electroluminescent device having a high quality, characterized in that 300nm ~ 100㎛. delete delete delete delete delete The method of claim 1,
The organic electroluminescent device, characterized in that the coating is made on the outermost surface of the sealing substrate or a protective film is additionally included. The method of claim 1,
And a flattening layer functioning as a buffer layer between an upper surface of the support substrate and a lower surface of the organic light emitting unit. The method of claim 1,
The organic electroluminescent device having a high picture quality, characterized in that the inner space partitioned by the support substrate and the sealing substrate is filled with an inert gas of nitrogen, neon or argon. The method of claim 1,
The organic electroluminescent device having a high picture quality, characterized in that the organic electroluminescent unit is sequentially stacked between the electrode layer and the electrode layer, a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, an electron injection layer.

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