KR102224029B1 - Organic light emitting display panel and display device - Google Patents

Abstract

The present invention may include a substrate and a first anti-reflection film formed on one side of the substrate to prevent reflection of external light. In addition, the present invention is formed on the entire surface of the other side of the substrate, includes at least one second anti-reflective film including a material absorbing light of the first wavelength band, is formed on the entire surface of the second anti-reflective film, and the second wavelength It provides an organic light emitting display panel and a display device including at least one third anti-reflective layer including a material that absorbs light in a band.

Description

Organic light emitting display panel and display device {ORGANIC LIGHT EMITTING DISPLAY PANEL AND DISPLAY DEVICE}

The present invention relates to an organic light emitting display panel and a display device.

In the field of flat panel display devices, until now, light and low power consumption liquid crystal display devices have been widely used, but liquid crystal display devices are non-emissive devices that cannot generate light by themselves. ratio), viewing angle, and large area.

Accordingly, the development of new flat panel display devices capable of overcoming the shortcomings of such liquid crystal display devices is being actively developed. As one of the new flat panel display devices, an organic light emitting display device is a light emitting device that generates light by itself, liquid crystal display Compared to the device, it has superior luminance, viewing angle, and contrast ratio, and because it does not require a backlight, it is possible to be lightweight and thin, and it is advantageous in terms of power consumption.

The organic light-emitting display panel of the organic light-emitting display device displays an image using light emitted from an organic light-emitting device connected to a thin film transistor in each pixel area, and the organic light-emitting device is formed of an organic material between an anode and a cathode. As a device that emits light by forming an organic light emitting layer and applying an electric field, it can be driven at a low voltage, consumes relatively little power, and can be manufactured on a light and flexible substrate.

When such an organic light-emitting display device is used outdoors or in a bright place, the visibility of the organic light-emitting display panel decreases, the luminance decreases, the contrast ratio characteristics decrease, and the element is caused by light introduced from the outside. There is a problem that the reliability is deteriorated due to deterioration.

In addition, when the organic light emitting display device has a structure that prevents reflection of external light, the viewing angle characteristic is deteriorated according to the structure, and the manufacturing cost is high.

An object of the present invention is to provide an organic light emitting display panel and display device that improves visibility, luminance, and contrast ratio characteristics, improves reliability, improves viewing angle characteristics, and reduces manufacturing costs.

In order to solve the above-described problem, the present invention, in one aspect, may include a substrate and a first antireflection film formed on one side of the substrate and preventing reflection of external light. In addition, the present invention is formed on the entire surface of the other side of the substrate, is formed on at least one second anti-reflection film and the second anti-reflective film including a material absorbing light of the first wavelength band, the light of the second wavelength band. It provides an organic light-emitting display panel including at least one third anti-reflective layer including a material that absorbs.

In another aspect, the present invention provides a display device including a substrate and an antireflection structure formed of at least one multilayer structure including a material that is deposited on the entire surface of the substrate and absorbs light in the visible or ultraviolet band. .

The present invention has the effect of improving visibility, luminance, and contrast ratio characteristics of an organic light emitting display panel and a display device, improving reliability, improving viewing angle characteristics, and reducing manufacturing costs.

1 is a system configuration diagram of a display device to which embodiments are applied.
2A is a schematic cross-sectional view of a display device to which embodiments are applied.
2B is a schematic cross-sectional view of a display device according to an exemplary embodiment.
3 is a cross-sectional view of an organic light emitting display panel according to another exemplary embodiment.
4 is a cross-sectional view of an organic light emitting display panel according to another exemplary embodiment.
5 is a cross-sectional view of an organic light emitting display panel according to another exemplary embodiment.
6 is a cross-sectional view of an organic light emitting display panel according to another exemplary embodiment.
7 is a graph showing a relationship between a thickness of a second anti-reflective layer and a reflectance of an organic light emitting display panel according to another exemplary embodiment.
8 is a graph showing the relationship between the thickness and transmittance of a third anti-reflective layer of an organic light emitting display panel according to another exemplary embodiment.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to elements of each drawing, it should be noted that the same elements are assigned the same numerals as possible, even if they are indicated on different drawings. In addition, in describing the embodiments of the present invention, when it is determined that a detailed description of a related known configuration or function may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

In addition, in describing the constituent elements of the invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are for distinguishing the constituent element from other constituent elements, and the nature, order, or order of the constituent element is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected or connected to that other component, but another component between each component It will be understood that elements may be “connected”, “coupled” or “connected”. In the same context, when it is described that a component is formed "above" or "below" another component, the component is all formed directly on the other component or indirectly through another component. It should be understood as including.

1 is a system configuration diagram of a display device to which embodiments are applied.

Referring to FIG. 1, the display device 100 includes 140, a data driver 120, a gate driver 130, a timing controller 110, and the like.

Here, the display device 100 may be an organic light emitting display device or a liquid crystal display device, but is not limited thereto.

First, the timing controller 110 controls the data driver 120 based on external timing signals such as vertical/horizontal synchronization signals (Vsync, Hsync) input from the host system, image data, and clock signals CLK. A data control signal (DCS) for controlling the gate driver 130 and a gate control signal (GCS) for controlling the gate driver 130 are output. In addition, the timing controller 110 converts the image data (data) input from the host system into a data signal format used by the data driver 120 and supplies the converted image data (data') to the data driver 120. have.

In response to the data control signal DCS and the converted image data data' input from the timing controller 110, the data driver 120 converts the image data data' into a data signal that is a voltage value corresponding to the grayscale value. It is converted into an analog pixel signal or data voltage) and supplied to the data lines D1 to Dm.

The gate driver 130 sequentially supplies scan signals (gate pulses, scan pulses, and gate-on signals) to the gate lines G1 to Gn in response to the gate control signal GCS input from the timing controller 110.

Meanwhile, each pixel P on the display panel 140 may be formed in a pixel region defined by the data lines D1 to Dm and the gate lines G1 to Gn and disposed in a matrix form. It may include a pixel electrode (Anode) as an electrode and a common electrode (Cathode) as a second electrode.

In each pixel P, gate lines G1 to Gn, data lines D1 to Dm, and high potential voltage lines for supplying a high potential voltage are formed. In addition, at least one transistor is formed in each pixel P.

In addition, since the display panel 140 according to the exemplary embodiment does not include a structure of a polarizing plate or a polarizing layer, in order to prevent the visibility, brightness, and contrast ratio characteristics from deteriorating due to reflection of light flowing from the outside, An antireflection film (not shown) made of a layered structure may be provided.

Specifically, the display device 100 is deposited on a substrate (not shown) and an entire surface of the substrate (not shown), and is formed of at least one multi-layer structure including a material absorbing light in the visible or ultraviolet band. (Not shown) may be included. Accordingly, a certain amount of visible light introduced from the outside of the display device 100 is absorbed to improve visibility, brightness, and contrast ratio characteristics. In addition, by protecting the components inside the display device 100 from ultraviolet rays, it is possible to prevent deterioration of the elements.

This will be described in more detail below with reference to the drawings.

2A is a schematic cross-sectional view of a display device to which embodiments are applied.

Referring to FIG. 2A, the display device 100 is deposited on the substrate 204 and the entire surface of the substrate 204, and is formed of one or more multi-layered structures including a material that absorbs light in the visible or ultraviolet band. A prevention structure 210 may be included.

The substrate 204 may be not only a glass substrate, but also a plastic substrate including polyethylen terephthalate (PET), polyethylen naphthalate (PEN), polyimide, or the like. In addition, a buffering layer for blocking penetration of impurity elements may be further provided on the substrate 204. The buffer layer may be formed of, for example, a single layer or multiple layers of silicon nitride or silicon oxide.

The anti-reflection structure 210 may be one or more multi-layers or multi-layers, and is made of, for example, an anti-reflection film comprising a material absorbing light in the visible band and an anti-reflection film comprising a material absorbing light in the ultraviolet band. I can.

Meanwhile, a display device 230 may be formed on the antireflection structure 210. The display device 230 may be, for example, an organic light emitting diode (OLED) including organic layers, and may be a liquid crystal display device including a cell and liquid crystal molecules.

In this specification, for convenience of description, an organic light-emitting display panel including an organic light-emitting diode is mainly described as an example, but it should be noted that the present disclosure is not limited thereto.

Meanwhile, an encapsulation layer 250 may be formed on the display device 230. The encapsulation layer 250 functions to protect the display device 230 from an external environment. The encapsulation layer 250 may be in the form of a thin thin film, may be in a form using a frit, which is a glass powder, or may be in a hybrid form using these forms. In addition, a frit sealing method using a frit may be used, or a face sealing method in which a thin film metal is deposited on the entire surface may be used.

2B is a schematic cross-sectional view of a display device according to an exemplary embodiment.

Referring to FIG. 2B, the display device 100 includes a low-reflective film 202 formed on one surface (lower surface in the drawing) of the substrate 204, and an antireflection structure formed on the other surface (upper surface in the drawing) of the substrate 204. 210, a display device 230 formed on the antireflection structure 210, and an encapsulation layer 250 formed on the display device 230. Here, the anti-reflection structure 210 may be formed of a second anti-reflective film 212 and a third anti-reflective film 214.

Specifically, the low-reflective film 202 may be attached to the surface opposite to the surface on which the anti-reflection structure 210 is formed on the substrate 204. In this specification, the low-reflective film 202 refers to the same structure as the first anti-reflective film 202. The low-reflective film 202, for example, when light is introduced from the outside (downward in the drawing), the external light is reflected from the substrate 204 to perform a function of preventing impairing the visibility or contrast characteristics. I can. The low-reflective film 202 may include a material that absorbs visible or ultraviolet rays, or may have a structure capable of reducing reflection of external light. In addition, the low-reflective film 202 has an appropriate refractive index so as to cause destructive interference between the light reflected from the interface between the substrate 204 and the low-reflective film 202 and the light reflected from the surface of the low-reflective film 202. It may also contain substances.

In the antireflection structure 210, the second antireflection layer 212 may include, for example, a material that absorbs light in a visible band. A material that absorbs light in the visible light band may be, for example, calcium (Ca) or calcium alloy.

Meanwhile, the absorption rate of light in the visible ray band introduced from the outside may increase in proportion to _{the thickness t 1 of the second anti-reflective layer 212.}

The third anti-reflective layer 214 may include, for example, a material that absorbs light in an ultraviolet band. Here, the material absorbing light in the ultraviolet band may be, for example, a metal oxide such as titanium oxide (TiOx), zinc oxide (ZnO), and tin oxide (SnOx). Since these materials have an energy bandgap of 380 nm or less, they are absorbed when ultraviolet rays are incident. The size of the material absorbing light in the ultraviolet band may be approximately 5 nm to 100 nm.

Here, the absorption rate of light in the visible ray band introduced from the outside may increase in proportion to _{the thickness t 2 of the third anti-reflective layer 214.}

On the other hand, in order to prevent the visibility, brightness, and contrast ratio characteristics from being deteriorated due to reflection of external light, the display device 100 is additionally located on the substrate 204, a conductive layer (not shown) and one or more low-reflection layers (not shown). It may include a pattern (not shown) made of a multi-layered structure made of Si). Here, the pattern (not shown) may be signal lines (not shown), electrodes of a transistor (not shown), a light blocking layer 216, and the like, which will be described in detail in the related drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail by taking an organic light emitting display panel as an example of the display device 100.

3 is a cross-sectional view of an organic light emitting display panel according to another exemplary embodiment.

Referring to FIG. 3, the organic light emitting display panel 200 is formed on a substrate 204 and one side of the substrate 204, and a first antireflection film ( 202), is formed on the entire surface of the other side of the substrate 204, is formed on the entire surface of the second anti-reflective film 212 and the second anti-reflective film 212 including a material absorbing light of the first wavelength band, It may include at least one third anti-reflective layer 214 including a material that absorbs light in the 2 wavelength band.

The organic light emitting display panel 200 may include a first insulating layer 222 sequentially formed on the third anti-reflective layer 214, a signal line, a planarization layer 228, and the like. In addition, the organic light emitting display panel 200 includes a first electrode 232 formed on the planarization layer 228, a bank 234 formed in a matrix shape along the edge of the first electrode 232, and the first electrode 232 An organic layer 236 formed to cover the bank 234, a second electrode 238 that is a common electrode formed on the organic layer 236, and an encapsulation layer 250 formed on the second electrode 238. I can.

In the light emission method of the organic light emitting display panel 200, a top emission method in which light emitted from the organic layer 236 is emitted in the direction of the encapsulation layer 250, and a top emission method in which the light emitted from the organic layer 236 is emitted in the direction of the encapsulation layer 250, There is a bottom emission method. The light emission method of the organic light emitting display panel 200 of the present specification is a lower light emission method for convenience of description, but the present invention is not limited thereto, and may be a top light emission method. In the case of the upper emission method, the first antireflection layer 202 and the antireflection structure 210 are positioned on the upper layer of the organic light emitting display panel 200.

On the other hand, the first anti-reflective film 202 means the same structure as the low-reflective film 202 of FIG. 2B. For example, when light is incident from the outside (the lower side in the drawing), the substrate 204 It may perform a function of preventing external light from being reflected and impairing visibility or contrast ratio characteristics. The first antireflection layer 202 may include a material that absorbs visible or ultraviolet rays, or may have a structure capable of reducing reflection of external light. In addition, the first anti-reflection film 202 has an appropriate refractive index so as to cause destructive interference between the light reflected at the interface between the substrate 204 and the low reflection film 202 and the light reflected from the surface of the low reflection film 202. It may also include a material having. Accordingly, the first anti-reflection film 202 has an effect of extinguishing by absorbing external light or causing a destructive interference phenomenon.

Here, the first wavelength band may be a visible light band, and the second wavelength band may be an ultraviolet band, but is not limited thereto.

The substrate 204 may be made of not only glass, but also PET, PEN, or polyimide-based plastic material.

Meanwhile, an antireflection structure 210 may be formed on the substrate 204 to prevent reflection of light flowing from the outside. In FIG. 3, as an example, an organic light-emitting display panel 200 having a double-layer structure of the second anti-reflective layer 212 and the third anti-reflective layer 214 is illustrated. However, this is for convenience of description, and the organic light emitting display panel 200 may be formed in a multilayer structure such as a triple layer or a quadruple layer.

The second anti-reflective layer 212 of the organic light emitting display panel 200 may be made of a material capable of absorbing light in the first wavelength band incident from the outside by matching the energy band gap with the light in the first wavelength band. have. The first wavelength band may be a visible light band. Such a material may be, for example, calcium or an alloy of calcium and another metal, but is not limited thereto, and may be another material capable of absorbing light in a visible ray band.

The second anti-reflective layer 212 performs a function of uniformly reducing external light in the first wavelength band over all wavelengths.

In addition, the second anti-reflective layer 212 may be a neutral density filter. The neutral density filter performs a function of constantly reducing the transmittance amount of light in the entire range of visible light, that is, in a wavelength range of 380 nm to 780 nm.

The thickness t ₁ of the second anti-reflective film 212 may be proportional to the amount of absorption of the second anti-reflective film 212 with respect to light in the visible ray band introduced from the outside. In other words, as the thickness t ₁ of the second anti-reflective layer 212 is increased, the amount of light in the visible ray band to be absorbed may increase. _{In terms of reflectivity, it means that the greater the thickness t 1} of the second anti-reflective layer 212, the less reflective external light may be.

Accordingly, by lowering the reflectance at which light in the visible band among external light is reflected by various wirings and electrodes inside the device, it is possible to prevent a decrease in visibility, a decrease in brightness, and a decrease in contrast ratio characteristics of the organic light-emitting display panel 200. .

_{In addition, by adjusting the thickness t 1} of the second anti-reflective layer 212, the transmittance of light may be adjusted. In the organic light emitting display panel 200 of the bottom emission type, since the second anti-reflective layer 212 is formed on the entire surface of the substrate 204, light generated from the organic layer 236 is also applied to the second anti-reflective layer 212. Because it passes, it is necessary to design an appropriate transmittance. Accordingly, through the second anti-reflective layer 212, there is an effect of controlling the transmittance of light in a trade-off relationship and the reflectance of external light.

On the other hand, the second anti-reflection film 212 is an incell type film deposited inside the organic light emitting display panel 200, and is formed by chemical vapor deposition (CVD) or physical vapor deposition (Physical Vapor Deposition). Vapor Deposition, PVD) can be formed. The second anti-reflective layer 212 may be made of a material having heat resistance so that properties are not deteriorated by heat generated during deposition or patterning of other structures.

_{The thickness t 1} of the second anti-reflective layer 212 may be thickened by increasing the deposition time, or may be thickened in the form of a multilayer structure through a plurality of deposition processes.

A third anti-reflective film 214 may be formed on the second anti-reflective film 212. Here, the third anti-reflective layer 214 may be made of a material having an energy band gap capable of absorbing light in the second wavelength band (for example, an ultraviolet band of 380 nm or less). For example, the third anti-reflective layer 214 may be made of a metal oxide such as TiOx, ZnO, and SnOx, but is not limited thereto, and any material capable of absorbing ultraviolet rays and having heat resistance may correspond to this.

_{Like the second anti-reflective film 212 described above, the thickness t 2} of the third anti-reflective film 214 of the organic light-emitting display panel 200 and the second anti-reflective film 212 introduced from the outside. The absorption amount of the third anti-reflective layer 214 for the light of the 2 wavelength band may be proportional. _{That is, as the thickness t 2} of the third anti-reflective layer 214 increases, the amount of light in the second wavelength band to be absorbed may increase, and reflectance of external light may decrease.

Light in the ultraviolet band incident from the outside may cause deterioration of internal devices such as transistors. Accordingly, as described above, by lowering the reflectance of light in the ultraviolet band, which is the second wavelength of external light, it is possible to prevent device deterioration or electrical characteristics of the OLED display panel 200 from deteriorating.

On the other hand, the size of the material absorbing light in the ultraviolet band of the third anti-reflective layer 214 may be a nanoscale size of 5 nm to 100 nm, and specifically, in the organic layer 236 of the organic light emitting display panel 200 It may be less than half the wavelength of the generated light.

Light introduced from the outside may be incident under the substrate 204, and in this case, light in the second wavelength band may be absorbed by the third anti-reflective layer 214. On the other hand, in the organic light emitting display panel 200 of the lower emission type, light generated from the organic layer 236 also passes through the third anti-reflective layer 214. At this time, when the size of the light absorbing material is larger than 1/2 of the wavelength of light generated in the organic layer 236, scattering of light may occur, thereby reducing visibility and brightness. Accordingly, the size of the material included in the third anti-reflective layer 214 may be less than 1/2 of the wavelength of light generated from the organic layer 236.

The third anti-reflective layer 214 may be made of a material having heat resistance so that properties are not deteriorated by heat generated during deposition or patterning of other structures such as transistors.

Meanwhile, since the organic light emitting display panel 200 according to the embodiments of the present invention has a structure that does not have a polarizing layer or a polarizing plate structure, light in the visible light band and light in the ultraviolet band introduced from the outside are It means non-polarization.

Meanwhile, the first insulating layer 222 of the organic light emitting display panel 200 may be a gate insulating layer, and SiO _x , SiN _x , SiON, Al ₂ O ₃ , TiO ₂ , Ta ₂ O ₅ , HfO ₂ , ZrO ₂ , It may be an inorganic insulating material including any one of BST and PZT, an organic insulating material including benzocyclobutene (BCB) or acrylic resin, or a combination thereof.

A transistor (not shown) or a plurality of signal lines (Line) may be formed on the first insulating layer 222, and a planarization layer 228 may be formed to planarize the transistor (not shown).

Here, at least one of the electrodes or signal lines of the transistor (not shown) may include one or more low-reflective layers (not shown), and this low-reflective layer (not shown) is external light introduced through the substrate 204. It may be made of a material that absorbs light, a light absorber is applied, or may be made of a metal oxide. This will be described in detail in the part related to FIG. 4.

Meanwhile, a first electrode 232 and a bank 234 are formed on the planarization layer 228.

Here, the first electrode 232 may be an anode electrode (anode), a relatively large work function value, a transparent conductive material, for example, a metal oxide such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), Mixtures of metals and oxides such as ZnO:Al or SnO2:Sb, poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDT), polypyrrole and polyaniline It may be made of a conductive polymer such as. In addition, the first electrode 232 may be a carbon nano tube (CNT), graphene, silver nano wire, or the like.

The bank 234 has a matrix-like lattice structure as a whole of the substrate 204, surrounds the edge of the first electrode 232, and exposes a part of the first electrode 232. The bank 234 may be formed of an inorganic insulating material such as SiNx or SiOx, or an organic insulating material such as benzocyclobutene or acrylic resin, or a combination thereof, but is not limited thereto.

Meanwhile, the organic layer 236 formed to cover the bank 234 and the first electrode 232 is a hole injection layer (HIL) so that holes and electrons can be transported smoothly to form excitons. , A hole transfer layer (HTL), an organic light emitting layer (EL), an electron transfer layer (ETL), an electron injection layer (EIL), and the like may be sequentially stacked and included.

The second electrode 238 may be a metal having a high reflectance in the case of a lower light emitting method, and a single layer of an alloy composed of a first metal, for example Ag, and a second metal, for example, Mg, etc. There may be multiple layers of. With respect to light incident from the outside, a ratio of reflection of external light from the second electrode 238 is greater than that of reflection from other components.

The encapsulation layer 250 positioned at the top may be formed in various ways in consideration of mechanical strength, moisture permeability, productivity, and the like so that the internal element can be protected from an environment such as moisture or oxygen from the outside.

4 is a cross-sectional view of an organic light emitting display panel according to another exemplary embodiment.

Referring to FIG. 4, the organic light emitting display panel 200 includes an antireflection structure 210 formed on a substrate 204, and the antireflection structure 210 includes a second antireflection layer 212 and a third antireflection layer. It can be made of (214). In addition, the organic light emitting display panel 200 may include a transistor formed on the antireflection structure 210, and the transistor includes a gate 223, a first insulating layer 222, a semiconductor layer 224, and a first electrode 232 A source electrode/drain electrode 225 electrically connected to) may be included. A planarization layer 228, a first electrode 232, a bank 234, an organic layer 236, a second electrode 238, and an encapsulation layer 250 are sequentially stacked on the transistor.

A description of the same configuration as the organic light emitting display panel 200 of FIG. 3 will be omitted.

As an example, the transistor of the organic light emitting display panel 200 of FIG. 4 has a bottom gate method. Here, the electrodes 223 and 225 of the transistor may include one or more low reflection layers 223b and 225b, and these low reflection layers 223b and 225b are made of a material that absorbs external light introduced through the substrate 204. Alternatively, a light absorber may be applied, or may be made of a metal oxide.

Specifically, the low reflection layers 223b and 225b are metal oxides such as Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO), or metals that absorb light such as Mo, Cr, Ti, Ta, Mn, and Nb, or these It may be made of an alloy of, and may have a black-based color.

When the low reflection layers 223b and 225b are metal oxides, between the light reflected from the surfaces of the low reflection layers 223b and 225b and the light reflected at the interface between the low reflection layers 223b and 225b and the conductive layers 223a and 223b Destructive interference occurs, blocking the reflection of external light.

In the case of the organic light-emitting display panel 200 of the present invention that does not include a structure of a polarizing plate or a polarizing layer, external light is reflected by various signal lines and electrodes 223 and 225, so that visibility, brightness, and contrast ratio are characteristic. Problems of lowering the back may occur. To prevent this problem, low reflection layers 223b and 225b may be provided on the organic light emitting display panel 200.

5 is a cross-sectional view of an organic light emitting display panel according to another exemplary embodiment.

Referring to FIG. 5, the organic light-emitting display panel 200 includes a substrate 204 having a first antireflection film 202 formed on one side (lower surface in the drawing) and the other side of the substrate 204 (upper surface in the drawing). ) Formed on the anti-reflection structure 210, may include a transistor formed on the anti-reflection structure 210.

The antireflection structure 210 of another embodiment may include a second antireflection film 212, a third antireflection film 214, and a fourth antireflection film 212'. Here, the fourth anti-reflective layer 212 ′ may include a material that absorbs light in the visible band or a material that absorbs light in the ultraviolet band. Also, depending on the thickness of the fourth anti-reflective layer 212 ′, light absorption or reflectance may vary.

However, the antireflection structure 210 of the organic light emitting display panel 200 according to the present invention is not limited thereto, and may be formed of a multilayer including more layers.

Meanwhile, the organic light emitting display panel 200 includes a first insulating layer 222 insulating the gate 223 and the semiconductor layer 224, and a second insulating layer 226 insulating the gate 223 and the source/drain electrodes 225. ), and a third insulating layer 227 insulating the source electrode/drain electrode 225 from the first electrode 232. In addition, a lower planarization layer 218 for insulating and planarizing the light blocking layer 216 and the semiconductor layer 224 may be additionally included.

Meanwhile, as an example of the transistor of FIG. 5, a top gate method is shown, and the organic light emitting display panel 200 additionally includes a light blocking layer 216 for protecting the semiconductor layer 224 from external light. Can include.

The light blocking layer 216 and the source electrode/drain electrode 225 include conductive layers 216a and 225a, and include one or more low reflection layers 216b and 225b to reduce reflection of light incident from the outside. I can. Although only one low reflection layer 216b and 225b is shown in the drawing, the present invention is not limited thereto, and low reflection layers 216b and 225b made of multiple layers may be provided.

Hereinafter, effects of the display device 100 according to the present invention will be described in detail in FIGS. 6 to 8.

6 is a cross-sectional view of an organic light emitting display panel according to another exemplary embodiment.

Referring to FIG. 6, in the case of the lower light emitting type organic light emitting display panel 200, while a user is using the display device 100, external light L1 and L2 may be incident from the lower portion of the substrate 204. have.

In the case of light in the visible light band among the external light (L1, L2), it is reflected by the substrate 204 or an internal signal line, the electrode of the transistor, the second electrode 238, etc., reducing visibility and reducing the brightness and contrast ratio characteristics. You can lower it.

In addition, in the case of light in the ultraviolet band among the external lights L1 and L2, the internal display device 230 and the transistor may be deteriorated.

As shown in FIG. 6, the first light L1, which is an external light, is reflected from the surface of the substrate 204, but is partially absorbed by the first antireflection film 202, or a phase delay occurs due to a difference in refractive index. It can also be extinguished through destructive interference.

The second light L2, which is external light, may pass through the substrate 204 and reach the antireflection structure 210. Of the second light L2, the light L2a ′ in the visible light band may be partially absorbed by a material absorbing visible light of the second anti-reflective layer 212. The second anti-reflective layer 212 may evenly absorb the wavelength of the entire visible light region, thereby evenly reducing the reflectance of the organic light emitting display panel 200.

In this case, the transmittance and reflectance may be adjusted by adjusting _{the thickness t 1} of the second anti-reflective layer 212. Specifically, the transmittance and reflectance are in inverse proportion, and after passing through the second anti-reflective layer 212, the reflectance of the reflected light to the outside of the substrate 204 is reduced by ^{the square of the transmittance (transmittance 2).} It is done. In other words, since the second anti-reflective film 212 is transmitted twice, the reflectance can be inversely proportional to the square of the transmittance. For example, the reflectance of the second anti-reflective film 212 designed with a transmittance of 70% is 49%, and the reflectance of the second anti-reflective film 212 designed with a transmittance of 60% is 36%.

Accordingly, due to the presence of the second anti-reflective layer 212, the luminous characteristics of the organic light emitting display panel 200, that is, visibility, brightness, contrast ratio characteristics, and the like may be improved.

Meanwhile, the light L2b' in the ultraviolet band among the second light L2 may pass through the second anti-reflective layer 212 and reach the third anti-reflective layer 214. Ultraviolet rays may be blocked by a material that absorbs light in the ultraviolet band of the third anti-reflection film 214, and the amount of absorption may be controlled by adjusting the _{thickness t 2.} Accordingly, deterioration of the internal device is prevented and the reliability of the device is improved.

In addition, reflection of external light is prevented by the low reflection layers 216b, 223b, 225b formed on the electrodes 223 and 225, the light blocking layer 216, and the signal line of the transistor, thereby improving visibility, brightness, and contrast ratio. I can.

In addition, since the antireflection structure 210 having a multilayer structure of the organic light emitting display panel 200 according to the present invention is deposited on the entire surface of the substrate 204, manufacturing cost is reduced.

In addition, since the anti-reflection structure 210 has a material that absorbs light in the visible and ultraviolet bands and is evenly distributed over the entire surface, the screen looks the same even when the viewing angle is changed, and the viewing angle characteristics are improved. The effect occurs.

7 is a graph illustrating a relationship between _{a thickness t 1} of a second anti-reflective layer and reflectance of an organic light emitting display panel according to another exemplary embodiment. Where t is the previously described t ₁ .

In FIG. 7, Ref. (Reference), which is a comparative example, means reflectance of the second electrode 238 made of metal in the organic light emitting display panel 200, and t is a second electrode made of calcium (Ca). It means _{the thickness t 1} of the antireflection film 212.

7, the second when the thickness (t ₁₎ of the anti-reflection film (212) 10nm, the reflectance was 60%, and the second when the thickness (t ₁₎ of the anti-reflection film (212) 20nm has 50% It can be seen that it is.

By the presence of the second anti-reflection film 212, the reflectance of the external light in the visible light band (400 nm to 700 nm), which is the aforementioned first wavelength band, is reduced, and the thickness t _{1 of the second anti-reflective film 212 is reduced.} It can be seen that the thicker it is, the more the reflectivity is reduced. Accordingly, visibility, luminance, and contrast ratio characteristics, which are luminous characteristics of the organic light-emitting display panel 200, are improved.

8 is a graph showing the relationship between the thickness and transmittance of a third anti-reflective layer of an organic light emitting display panel according to another exemplary embodiment.

In FIG. 8, Ref. (Reference), which is a comparative example, refers to the reflectance of the second electrode 238 made of metal in the organic light emitting display panel 200, and t is the third antireflection film 214 made of ZnO. It means the thickness (t ₂ ).

_{When the thickness t 2} of the third anti-reflective film 214 is 50 nm, it can be seen that the transmittance in the ultraviolet band (200 nm to 380 nm) is approximately 20% to 35%, and the third anti-reflective film 214 When the thickness t ₂ of is 100 nm, it can be seen that the transmittance of light in the ultraviolet band is approximately 5% to 15%. In addition, from the viewpoint of reflectance, it can be seen that the thicker the _{thickness t 2, the lower the reflectance.}

Therefore, due to the presence of the third anti-reflection film 214, the reflectance of external light in the ultraviolet band (the second wavelength band described above) is reduced, and deterioration of internal components can be prevented.

The embodiments have been described above with reference to the drawings, but the present invention is not limited thereto.

The terms such as "include", "consist of" or "have" described above mean that the corresponding component may be embedded, unless otherwise specified, and thus other components are not excluded. It should be construed as being able to further include other components. All terms, including technical or scientific terms, unless otherwise defined, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms generally used, such as terms defined in the dictionary, should be interpreted as being consistent with the meaning in the context of the related technology, and are not interpreted as ideal or excessively formal meanings unless explicitly defined in the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Claims (10)

Board;
A first anti-reflection film formed on one side of the substrate and preventing reflection of external light;
At least one second anti-reflective layer formed on the entire surface of the other side of the substrate and including a material absorbing light in a first wavelength band, which is a visible ray band;
At least one third anti-reflective film formed on the entire surface of the second anti-reflective film and comprising a material absorbing light of a second wavelength band, which is an ultraviolet band;
A display device positioned on the third anti-reflection film in a region overlapping with the second anti-reflection film and the third anti-reflection film and generating light of the first wavelength band emitted below the substrate; And
Including a transistor positioned on the third anti-reflective layer,
At least one of the electrodes of the transistor includes a conductive layer and at least one low-reflective layer positioned between the conductive layer and the third anti-reflective layer,
The organic light-emitting display panel, wherein the low-reflective layer is made of a material that absorbs external light introduced through the substrate, a light absorber is applied, or is made of a metal oxide. The method of claim 1,
The organic light-emitting display panel, wherein the thickness of the second anti-reflective film is proportional to the amount of absorption of the second anti-reflective film with respect to the light of the first wavelength band introduced from the outside. The method of claim 1,
An organic light-emitting display panel, wherein the thickness of the third anti-reflective layer is proportional to the amount of absorption of the third anti-reflective layer with respect to the light of the second wavelength band introduced from the outside and transmitted through the second anti-reflective layer. The method of claim 1,
The size of the material absorbing light of the second wavelength band of the third anti-reflection film is,
An organic light emitting display panel, characterized in that less than 1/2 of a wavelength of light generated by the display device. The method of claim 1,
The second anti-reflection layer is an organic light emitting display panel, characterized in that the neutral density filter (Neutral Density Filter). The method of claim 1,
The organic light-emitting display panel, wherein the visible light band and the ultraviolet light band are non-polarized. delete Board;
An antireflection structure formed on the entire surface of the substrate and having at least one multilayer structure including a material absorbing light in the visible or ultraviolet band;
A display device positioned on the anti-reflective structure in an area overlapping the anti-reflective structure and generating light in the visible light band emitted below the substrate; And
It is located on the anti-reflective structure, and includes a pattern made of a multi-layered structure consisting of a conductive layer and at least one low-reflective layer positioned between the conductive layer and the anti-reflective structure,
The display device according to claim 1, wherein the low reflection layer is made of a material that absorbs external light introduced through the substrate, a light absorber is applied, or is made of a metal oxide. The method of claim 8,
A display device, wherein a low-reflective film is attached to a surface of the substrate opposite to a surface on which the anti-reflection structure is formed. delete

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