KR20170080343A - Transparent flexible display device - Google Patents

Abstract

The present invention provides a light control device capable of uniformly spreading a sealant during a laminating process, comprising a first substrate and a second substrate facing each other, a first substrate facing the first substrate, A second electrode disposed on one surface of the second substrate facing the first substrate, liquid crystal cells arranged between the first electrode and the second electrode, the liquid crystal cells transmitting or shielding light, A first dam structure which surrounds the inside of the sealant contacting with the liquid crystal cells and is provided at a boundary between the sealant and the liquid crystal cells and a second dam structure which surrounds the outer side of the sealant, Dam structures.

Description

TRANSPARENT FLEXIBLE DISPLAY DEVICE [0002]

The present invention relates to a transparent flexible display device.

Recently, as the information age is approaching, a display field for processing and displaying a large amount of information has been rapidly developed, and various display devices have been developed in response to this. Specific examples of such a display device include a liquid crystal display device (LCD), a plasma display panel (PDP), a field emission display device (FED), an electroluminescent display device An electroluminescence display device (ELD), and an organic light emitting diode (OLED).

The organic light emitting display device using the dual organic light emitting device has high brightness and low operating voltage characteristics and is self-emitting type that emits light by itself, so that the contrast ratio is good and the ultra thin display can be realized . In addition, the response time is as short as several microseconds, the moving picture is easy to implement, the viewing angle is not limited, and the characteristic is stable even at low temperatures.

2. Description of the Related Art In recent years, a lot of efforts have been made to implement a flat panel display device as a flexible display device in order to realize various purposes such as easy portability and various types of configurations and prevention of breakage. For example, a flexible liquid crystal display device and a flexible organic light emitting display device can be manufactured by disposing a liquid crystal display device and an organic light emitting display device on a flexible substrate such as plastic.

In addition, a transparent flexible display device has been developed in which a transparent portion is provided in such a flexible display device, and when the image is not implemented, the transparent flexible display device can display objects on the back surface thereof.

1 is a view schematically showing a conventional transparent flexible display device.

Referring to FIG. 1, a conventional transparent flexible display device includes an antireflection film 1, an adhesive 2, a sealing layer 3, a transmission portion 4, a thin film transistor 5, a multi-buffer layer 6 ), A transparent PI layer (7), and a color filter layer (8).

The antireflection film 1 is disposed on the upper and lower sides of the transparent flexible display device, and uses a flexible polymer material. Refractive index and thickness are designed according to the properties of such a polymer material, and reflectance caused by external light is induced to cancel out interference to reduce reflectance.

In order to improve the adhesion of the antireflection film (1), the antireflection film (1) is disposed on the side in contact with the transparent flexible display device. Although not shown in the drawings, a support made of a polymer or metal is required between the adhesive 2 and the antireflection film 1. The thickness of the antireflection film 1 is thin so that uniform deposition can be achieved.

The sealing layer 3 serves to seal the light emitting layer, and is located at the top of the light emitting layer.

The transmissive portion 4 is a region where the color filter layer 8 is not disposed in the same layer as the color filter layer 8 and external light passes through.

The thin film transistor 5 includes a driving element for driving an image in a display mode.

The multi-buffer layer 6 prevents moisture from permeating into the transparent flexible display device.

Although the transparent PI layer 7 is not shown in the drawing, the sacrificial layer is removed and serves as a substrate of a transparent flexible display device.

Such conventional transparent flexible display devices have the following problems.

First, the sum of the thicknesses of the antireflection film 1, the adhesive 2 and the support of the transparent flexible display device generally has a value of 75 to 100 탆. Such a thickness may decrease the flexibility of the transparent flexible display device .

Second, cracks in the organic and inorganic layers may occur due to the low flexibility of such a transparent flexible display device.

Third, when bending a transparent flexible display device, it may be difficult to design a neutral plane that reduces the influence of external force.

Therefore, the present inventors have studied a method for maximizing the flexibility of the transparent flexible display device while preventing the increase of the reflectance of the transparent flexible display device while minimizing the thickness of the antireflection film.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a transparent flexible display device in which an antireflection film, an adhesive, and a support are removed to minimize the thickness.

Another object of the present invention is to provide a transparent flexible display device with improved flexibility.

Another object of the present invention is to provide a transparent flexible display device with reduced reflectance and improved visibility.

According to an aspect of the present invention, there is provided a transparent flexible display device including a substrate including a display region and a transmissive region, a thin film transistor layer formed on the substrate and including an inorganic layer, And a first reflection reduction part provided between the thin film transistor layer and the light emitting element layer, wherein the inorganic layer has an opening area in the transmission area, and the first reflection reduction part comprises: And is provided in the transmission region.

And a second reflection reducing member disposed on the bottom surface of the substrate.

According to the solution of the above-mentioned problems, the following effects can be obtained.

First, it is possible to obtain a transparent flexible display device in which the thickness is minimized to improve the aesthetics.

Secondly, it is possible to obtain a transparent flexible display device in which flexibility is improved by minimizing the thickness.

Third, a transparent flexible display device capable of minimizing the thickness and preventing cracks can be obtained.

Fourth, a transparent flexible display device with improved reflectivity and visibility can be obtained.

In addition to the effects of the present invention mentioned above, other features and advantages of the present invention will be described below, or may be apparent to those skilled in the art from the description and the description.

1 is a schematic view showing a cross-sectional view of a general transparent flexible display device
2 is a cross-sectional view showing a transparent flexible display device according to a first embodiment of the present invention.
3 is a diagram showing the effect of the first reflection reducing section.
4 is a cross-sectional view showing a transparent flexible display device according to a second embodiment of the present invention.
5 is a diagram showing the effect of the second reflection reducing section.
6 is a diagram showing the effects of the first and second reflection reduction sections.
7 is a cross-sectional view showing a transparent flexible display device according to a third embodiment of the present invention.
8 is a cross-sectional view showing a transparent flexible display device according to a fourth embodiment of the present invention.
9 is a cross-sectional view showing a transparent flexible display device according to a fifth embodiment of the present invention.
10 is a cross-sectional view showing a transparent flexible display device according to a sixth embodiment of the present invention.
11 is a further cross-sectional view showing a transparent flexible display device according to a sixth embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, and the like disclosed in the drawings for describing the embodiments of the present invention are illustrative, and thus the present invention is not limited thereto. Like reference numerals refer to like elements throughout the specification. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. In the case where the word 'includes', 'having', 'done', etc. are used in this specification, other parts can be added unless '~ only' is used. Unless the context clearly dictates otherwise, including the plural unless the context clearly dictates otherwise.

In interpreting the constituent elements, it is construed to include the error range even if there is no separate description.

In the case of a description of the positional relationship, for example, if the positional relationship between two parts is described as 'on', 'on top', 'under', and 'next to' Or " direct " is not used, one or more other portions may be located between the two portions.

In the case of a description of a temporal relationship, for example, if the temporal relationship is described by 'after', 'after', 'after', 'before', etc., May not be continuous unless they are not used.

The first, second, etc. are used to describe various components, but these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical spirit of the present invention.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other, partially or wholly, technically various interlocking and driving, and that the embodiments may be practiced independently of each other, It is possible.

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

2 is a view showing a transparent flexible display device according to the present invention. 3 is a view showing light incident on a transmission portion and light reflected by a transparent flexible display device according to the present invention.

Referring to FIG. 2, the organic light emitting diode display according to an exemplary embodiment of the present invention includes a display unit and a transmissive unit provided on a substrate 105. First, the configuration of the display unit will be described and a description of the transmission unit will be given.

A multi-buffer layer 107, a passivation layer 145, a planarization layer 171, an inorganic layer 173, a bank layer 175, an anode electrode 180, and a passivation layer 173 are formed on the substrate 105 of the display unit. An organic light emitting layer 190, and a cathode electrode 200.

The substrate 105 may be a transparent plastic film. For example, the substrate 105 may include a COP (cyclo olefin polymer) such as a cellulose resin such as TAC (triacetyl cellulose) or DAC (diacetyl cellulose), a Norbornene derivative, polyolefin such as polyolefin such as acrylic resin, polycarbonate, PE or polypropylene such as poly (methylmethacrylate), polyvinyl alcohol (PVA), polyetheretherketone (PES) sulfide), polyetheretherketone (PEEK), polyetherimide (PEI), polyethylenenaphthalate (PEN) and polyethyleneterephthalate (PET), polyimide (PI), polysulfone (PSF) But is not limited thereto.

The multi-buffer layer 107 may include an oxide / nitride-containing inorganic material such as Si, Al, Ba, Mo, Cu, Mo, And serves to prevent diffusion of a substance contained on the substrate 105 into the thin film transistor T during a high temperature process during the manufacturing process of the thin film transistor T. [ In addition, the multi-buffer layer 107 can also prevent moisture and moisture from entering the inside of the transparent flexible display device.

The thin film transistor layer T includes an active layer 110, a gate insulating layer 120, a gate electrode 130, an interlayer insulating layer 140, a source electrode 150, and a drain electrode 160.

The active layer 110 is formed on the substrate 105 so as to overlap with the gate electrode 130. The active layer 110 may be formed of a silicon-based semiconductor material or an oxide-based semiconductor material. Although not shown, a light shielding film may be additionally formed between the substrate 105 and the active layer 110. In this case, external light incident through the lower surface of the substrate 105 is shielded by the light shielding film, The problem that the active layer 110 is damaged by external light can be prevented.

The gate insulating layer 120 is formed on the active layer 110. The gate insulating layer 120 functions to isolate the active layer 110 from the gate electrode 130. The gate insulating layer 120 may be formed of an inorganic insulating material such as a silicon oxide layer (SiO _x ), a silicon nitride layer (SiN _x ), or a multilayer thereof. However, the gate insulating layer 120 is not limited thereto. The gate insulating layer 120 may extend to the region PA.

The gate electrode 130 is formed on the gate insulating layer 120. The gate electrode 130 is formed to overlap the active layer 110 with the gate insulating layer 120 therebetween. The gate electrode 130 may be formed of any one selected from the group consisting of Mo, Al, Cr, Au, Ti, Ni, Ne, And may be a single layer or multiple layers made of these alloys, but it is not necessarily limited thereto.

The interlayer insulating layer 140 is formed on the gate electrode 130. The interlayer insulating layer 140 may be formed of the same inorganic insulating material as the gate insulating layer 120, for example, a silicon oxide layer (SiO _x ), a silicon nitride layer (SiN _x ), or a multilayer thereof. However, It is not.

The source electrode 150 and the drain electrode 160 are formed to face each other on the interlayer insulating layer 140. The first contact hole CH1 exposing the one end region of the active layer 110 and the second contact hole CH1 exposing the other end region of the active layer 110 are formed in the gate insulating layer 120 and the interlayer insulating layer 140, The source electrode 150 is connected to the other end region of the active layer 110 through the second contact hole CH2 and the drain electrode 160 is connected to the first contact hole CH2, (CH1) to the one end region of the active layer (110).

The source electrode 150 may include a lower source electrode 151, a central source electrode 152, and an upper source electrode 153.

The lower source electrode 151 may be formed between the interlayer insulating layer 140 and the central source electrode 152 to improve adhesion between the interlayer insulating layer 140 and the central source electrode 152. [ have. In addition, the lower source electrode 151 may protect the lower surface of the central source electrode 152, thereby preventing the lower surface of the central source electrode 152 from being corroded. Therefore, the degree of oxidation of the lower source electrode 151 may be less than the degree of oxidation of the central source electrode 152. That is, the material of the lower source electrode 151 may be made of a material having higher corrosion resistance than the material of the central source electrode 152. As described above, the lower source electrode 151 serves as an adhesion promoting layer or an anti-corrosion layer, and may be made of an alloy of molybdenum and titanium (MoTi), but is not limited thereto.

The central source electrode 152 is formed between the lower source electrode 151 and the upper source electrode 153. The central source electrode 152 may be made of copper (Cu), which is a metal having a low resistance, but is not limited thereto. The central source electrode 152 may be formed of a metal having a relatively lower resistance than the lower source electrode 151 and the upper source electrode 153. The thickness of the central source electrode 152 may be greater than the thickness of the lower source electrode 151 and the upper source electrode 153 to reduce the total resistance of the source electrode 150. [

The upper source electrode 153 is formed on the upper surface of the central source electrode 152 to prevent the upper surface of the central source electrode 152 from being corroded. Thus, the degree of oxidation of the upper source electrode 153 may be less than the degree of oxidation of the central source electrode 152. That is, the material of the upper source electrode 153 may be made of a material having higher corrosion resistance than the material of the central source electrode 152. The upper source electrode 153 may be made of a transparent conductive material such as ITO, but is not limited thereto.

The drain electrode 160 may include a lower drain electrode 161, a center drain electrode 162, and an upper drain electrode 163, similar to the source electrode 150 described above.

The lower drain electrode 161 is formed between the interlayer insulating layer 140 and the central drain electrode 162 to improve adhesion between the interlayer insulating layer 140 and the center drain electrode 162 Also, the lower surface of the central drain electrode 162 can be prevented from being corroded. Therefore, the degree of oxidation of the lower drain electrode 161 may be lower than the degree of oxidation of the center drain electrode 162. That is, the material forming the lower drain electrode 161 may be made of a material having a higher corrosion resistance than the material forming the center drain electrode 162. As described above, the lower drain electrode 161 may be made of the same molybdenum and titanium alloy (MoTi) as the lower source electrode 151, but is not limited thereto.

The central drain electrode 162 is formed between the lower drain electrode 161 and the upper drain electrode 163 and may be made of the same copper as the central source electrode 152 described above, It is not. The center drain electrode 162 may be made of a metal having a lower resistance than the lower drain electrode 161 and the upper drain electrode 163. The thickness of the center drain electrode 162 may be greater than the thickness of each of the lower drain electrode 161 and the upper drain electrode 163 to reduce the total resistance of the drain electrode 160.

The upper drain electrode 163 is formed on the upper surface of the center drain electrode 162 to prevent the upper surface of the center drain electrode 162 from being corroded. Accordingly, the degree of oxidation of the upper drain electrode 163 may be smaller than the degree of oxidation of the center drain electrode 162. That is, the material of the upper drain electrode 163 may be made of a material having higher corrosion resistance than the material of the central drain electrode 162. The upper drain electrode 163 may be made of a transparent conductive material such as ITO, but is not limited thereto.

The upper drain electrode 163 may be formed of the same material and the same thickness as the upper source electrode 153 and the center drain electrode 162 may be formed of the same material and the same thickness as the central source electrode 152 And the lower drain electrode 161 may be formed of the same material and the same thickness as the lower source electrode 151. In this case, the drain electrode 160 and the source electrode 150 may be formed at the same time There is an advantage that it can be formed.

The structure of the thin film transistor layer T as described above is not limited to the structure shown in the drawings, but may be variously modified in a structure known to those skilled in the art. For example, although the top gate structure in which the gate electrode 130 is formed on the active layer 110 is shown in the drawing, the gate electrode 130 may be formed on the bottom layer of the active layer 110, Or a bottom gate structure.

The passivation layer 145 is formed on the thin film transistor layer T and more specifically on the upper surfaces of the source electrode 150 and the drain electrode 160. The passivation layer 145 functions to protect the thin film transistor layer T. The passivation layer 145 may be formed of an inorganic insulating material such as a silicon oxide film (SiOX) or a silicon nitride film (SiNX). However, the present invention is not limited thereto.

The planarization layer 171 is formed on the passivation layer 165. The planarization layer 171 functions to flatten the upper surface of the substrate 105 on which the thin film transistor T is formed. The planarization layer 171 may be formed of an organic insulating material such as an acryl resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. However, the present invention is not limited thereto.

The inorganic layer 173 may be made of a material including an oxide and a nitride, and may be made of an inorganic material such as SiNx, SiOx, TiOx, AlOx, IGO, IZO, IGZO, or the like. The inorganic layer 173 serves to prevent moisture from penetrating into the inside, and generally has a high refractive index.

The bank layer 175 is formed on the inorganic layer 173 and includes a third contact hole CH3 exposing the source electrode 150 in the passivation layer 145 and the planarization layer 171. [ Thus, the bank layer 175 can prevent moisture from being permeated into the transparent flexible display device. The bank layer 175 may be formed of an organic insulating material such as polyimide resin, acryl resin, benzocyclobutene (BCB), or the like, but is not limited thereto. Also, such a bank layer 175 is made of an organic material and generally has a low refractive index.

The anode electrode 180 is formed on the planarization layer 170. The third contact hole CH3 exposing the source electrode 150 is formed in the passivation layer 165 and the planarization layer 170. The third contact hole CH3 is formed in the passivation layer 165 and the planarization layer 170, And the anode electrode 180 are connected to each other.

Although not shown, the organic light emitting layer 190 may have a structure in which a hole injecting layer, a hole transporting layer, an organic light emitting layer, an electron transporting layer, and an electron injecting layer are sequentially stacked. However, one or more layers of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer may be omitted. The organic light emitting layer may be formed to emit light of the same color, for example white, for each pixel, or may emit light of different colors, for example, red, green, or blue, for each pixel.

The transmissive portion of the transparent flexible display device according to the present invention includes a substrate 105, a multi-buffer layer 107, a gate insulating layer 120, an interlayer insulating layer 140, a passivation layer 145, a planarization layer 171, A bank layer 173, a bank layer 175, and a cathode electrode 200. The description of the overlapping portion with the display portion will be omitted.

In the transmissive portion, the four layers of the multi-buffer layer 107, the gate insulating layer 120, the interlayer insulating layer 140, and the passivation layer 145 are formed by depositing the passivation layer 145, which is the uppermost layer, An opening region (region A) is formed as shown by the process. Thereafter, the planarization layer 171 is entirely deposited on the opening region (region A), and the planarization layer 171 is brought into contact with one surface of the substrate 105.

A planarization layer 171 as a first layer is formed on the upper surface of the substrate 105 corresponding to the lower surface and the A region of the passivation layer 145 in order and the upper surface of the planarization layer 171 is provided with an inorganic layer (173) is formed. A bank layer 175 as a third layer is formed on the upper surface of the inorganic layer 173 and the cathode electrode 200 is entirely deposited on the bank layer 175. Here, the first to third layers may have different refractive indices.

At this time, the flattening layer 171, the inorganic layer 173, and the bank layer 175 on the transmission portion are defined as the first reflection reducing portion 170. An object of the present invention is to provide a transparent flexible display device including an anti-reflection part of an in-cell type capable of reducing the reflectance while minimizing the thickness of the transparent flexible display device. The reflector 170 may have a structure for increasing the transmittance of the light incident to the outside and reducing the reflectance.

 For example, if the refractive index of the substrate 105 in the opening region (region A) contacting the planarization layer 171 is n1 and the refractive index of the planarization layer (region A) formed on the upper surface of the substrate 105 in the opening region And the refractive index of the inorganic layer 173 formed on the upper surface of the planarization layer 171 is n3 and the refractive index of the bank layer 175 formed on the upper surface of the inorganic layer 173 And when the refractive index of the air layer is n5, the magnitude of the refractive index can be reduced steadily from n5 to n1.

Here, when the refractive index of a specific layer is assumed to be x, the refractive index difference between x and x-1 may be smaller than the refractive index difference between x and x-2. In addition, the refractive index difference between x and x + 1 may be smaller than the refractive index difference between x and x + 2. If the refractive index difference between the specific layer and the nearest layer is designed to have a small refractive index difference from the non-adjacent layer, the ratio of the reflected light to the incident external light can be reduced.

That is, referring to FIG. 3 and Equation 1, R1%, R2%, and R3% that are reflected can be calculated.

Assuming that the refractive index of the planarization layer 175 shown in FIG. 3 is n1 and the refractive index of the inorganic layer 173 disposed at the bottom is n2, the light reflected at the interface between the planarization layer 175 and the inorganic layer 173 The light follows the formula shown in equation (1). Therefore, the smaller the value of (n1-n2) located in the molecule, the smaller the ratio of the reflected light to the incident light.

In summary, if the difference in refractive index between the layers of the first reflection reducing section 170 disposed between the air layer and the transparent flexible display device is gradually reduced, the reflectance of the incident light can be reduced. That is, the reflectance is reduced, the visibility can be improved when the image is implemented in the transparent flexible display device, and a clearer transparent mode can be realized when the image is not implemented. Further, in the structure using the conventional antireflection film and adhesive, a transparent flexible display device in which the thickness is minimized can be obtained by using the first reflection reducing portion 170 of the in-cell type, whereby flexibility is secured and cracks can be prevented .

In addition, the first reflection reducing portion 170 of the transparent flexible display device according to the present invention can obtain the effect of reducing the reflectance by alternately depositing the organic material and the inorganic material.

That is, after a first layer including an inorganic material having a low refractive index is formed on the upper surface of the substrate 105 in the opening region (region A), a second layer containing an organic material having a high refractive index is formed on the first layer upper surface . Thereafter, a third layer including an inorganic material having a low refractive index may be formed on the upper surface of the second layer. However, the present invention is not limited thereto, and an inorganic material having a high refractive index and an organic material having a low refractive index may be alternately stacked. For example, the first layer has a refractive index of 1.4 or less when using an organic material of acrylic resin like the planarization layer 171, and the second layer has a refractive index of 1.4 or less, such as inorganic layer 173, When the material is used, the refractive index of the third layer is higher than 1.4 and the refractive index of the third layer is lower than 1.4 when an organic material of acrylic resin such as the bank layer 175 is used.

When an inorganic material having a high refractive index and an organic material having a low refractive index are alternately stacked, destructive interference can be induced with respect to a reflected wavelength by using external light. That is, the destructive interference can be induced by changing the thickness of the laminated structure and the material of each layer using the following equation (2). When the wavelength of the incident light is?, The thickness of the laminated structure is d, and the refractive index of the laminated structure is n, destructive interference according to the following equation (2) can be induced.

In summary, when each layer of the first reflection reducing portion 170 disposed between the air layer and the transparent flexible display device is alternately stacked with the inorganic layer having a high refractive index and the organic layer having a low refractive index, light reflected by the first reflection reducing portion 170 is canceled And the reflectance is reduced. That is, the reflectance is reduced, the visibility can be improved when the image is implemented in the transparent flexible display device, and a clearer transparent mode can be realized when the image is not implemented. Further, in the structure using the conventional antireflection film and adhesive, a transparent flexible display device in which the thickness is minimized can be obtained by using the first reflection reducing portion 170 of the in-cell type, whereby flexibility is secured and cracks can be prevented .

Although the first reflection reduction unit 170 is shown as being composed of three layers in the figure, it is not limited thereto. For example, a plurality of layers having a gradually decreasing refractive index, and may be formed of a plurality of layers in which a high refractive index and a low refractive index are alternately deposited, and the three layers of the first reflective reducing portion 170 are repeated Deposited structure.

4 shows a transparent flexible display device according to a second embodiment of the present invention. 5 is a diagram schematically showing the effect of the second reflection reducing section. 6 is a diagram showing the effect of the present invention using the first reflection reduction unit and the second reflection reduction unit of the transparent flexible display device according to the present invention.

Referring to FIG. 4, the transparent flexible display device according to the second embodiment of the present invention may include a second reflection reducing section 103 on the bottom surface of the substrate 105. The transparent flexible display device according to the second embodiment is provided with the second reflection reducing part 103 in addition to the first embodiment, and a description of the overlapping parts will be omitted.

The second reflection reducing portion 103 is disposed on the lower surface of the substrate 105 and serves to reduce the reflectance of the transparent flexible display device according to the second embodiment of the present invention.

The second reflection reducing portion 103 may be formed of an inorganic material including SiNx, SiOx, TiOx, AlOx, IGO, IZO and IGZO, and may be formed of a plurality of layers. For example, the second reflection reducing section 103 is disposed on the lower surface of the substrate 105 and includes a first reflection reducing layer 103a having a low refractive index and a second reflection reducing layer 103b disposed on the lower surface of the first reflection reducing layer 103a. (103b). Here, the first reflection reducing layer 103a and the second reflection reducing layer 103b may have different refractive indices.

At this time, the refractive index of the first reflection reducing layer 103a and the refractive index of the second reflection reducing layer 103b may be set to be different from each other to reduce the reflectance. For example, the refractive index of the first reflection reduction layer 103a can be set to be smaller than that of the second reflection reduction layer 103b. The difference between the refractive index of the first reflection reduction layer 103a and the refractive index of the second reflection reduction layer 103b can be set small.

Here, when the refractive index of a specific layer of the second reflection reduction unit 103 is x, the refractive index difference between x and x-1 may be smaller than the refractive index difference between x and x-2. In addition, the refractive index difference between x and x + 1 may be smaller than the refractive index difference between x and x + 2. If the refractive index difference between the specific layer and the nearest layer is designed to have a small refractive index difference from the non-adjacent layer, the ratio of the reflected light to the incident external light can be reduced. The ratio of the reflected light can be calculated by referring to FIG. 5 and the above-mentioned Equation 1, and the reflected R2% can be calculated.

Assuming that the refractive index of the second reflection reduction layer 103b shown in FIG. 5 is n1 and the refractive index of the first reflection reduction layer 103a disposed thereunder is n2, the second reflection reduction layer 103b and the second reflection reduction layer 103b The light reflected at the interface of the first reflection reducing layer 103a follows the formula shown in the above-mentioned formula (1). Therefore, the smaller the value of (n1-n2) located in the numerator of Equation 1, the smaller the ratio of the reflected light to the incident light.

In summary, if the difference between the refractive indexes of the respective layers of the second reflection reducing section 103 disposed between the air layer and the transparent flexible display device is gradually reduced, the reflectance to the incident light can be reduced. That is, the reflectance is reduced, the visibility can be improved when the image is implemented in the transparent flexible display device, and a clearer transparent mode can be realized when the image is not implemented. Further, in the structure using the conventional antireflection film and adhesive, a transparent flexible display device in which the thickness is minimized can be obtained by using the first reflection reducing portion 170 of the in-cell type, whereby flexibility is secured and cracks can be prevented .

In addition, the reflectance can be reduced by alternately laminating the second reflection reducing portion with an inorganic material having a high refractive index and an organic material having a low refractive index. The transparent flexible display device according to the second embodiment of the present invention may include a first reflection reducing portion 170 and a second reflection reducing portion 103 at the same time, And a second reflection reduction section 103. The second reflection reduction section 103 is formed of a transparent material.

6 is a view showing the effect of the first reflection reducing section and the second reflection reducing section of the transparent flexible display device according to the present invention.

Referring to FIG. 6, the transparent flexible display device according to the second embodiment of the present invention is provided with a second reflection reducing section 103 having a low refractive index on the bottom surface and a high refractive index A passivation layer 171 having a low refractive index is disposed on an upper surface of the substrate 105 and an inorganic layer 173 having a high refractive index is disposed on an upper surface of the passivation layer 171, And a bank layer 175 having a low refractive index is disposed on the upper surface of the lower electrode 173.

When each layer on the transparent portion of the transparent flexible display device has a laminate structure having a high refractive index and a low refractive index as described above, external light can induce destructive interference with reflected light as shown in Equation (2) .

To summarize, each layer of the first reflection reducing portion 170 and the second reflection reducing portion 103 disposed between the air layer and the transparent flexible display device is alternately made of an inorganic layer having a high refractive index and an organic layer having a low refractive index When stacked, the reflected light is canceled by the incident light and the reflectance is reduced. That is, the reflectance is reduced, the visibility can be improved when the image is implemented in the transparent flexible display device, and a clearer transparent mode can be realized when the image is not implemented. Further, in the structure using the conventional antireflection film and adhesive, the transparent flexible display device with minimized thickness can be obtained by using the insensitive reflection reducing portion 170, and flexibility can be ensured and cracks can be prevented.

FIG. 7 is a diagram showing a second reflection reducing section of the transparent flexible display device according to the third embodiment of the present invention. FIG. This is a modification or addition of a part of the configuration of the second embodiment according to Figs. 4 to 6, and a description of the overlapping portions will be omitted.

The transparent flexible display device according to the third embodiment of the present invention may additionally include first scattering particles 103c in the second reflection reducing section 103. [ In the drawing, the first scattering particles 103c are disposed on the second reflection reducing layer 103b, but the present invention is not limited thereto. For example, the first scattering particles 103c may be disposed on the first reflection reducing layer 103a or on both of the plurality of layers.

As shown in FIG. 7, the first scattering particles 103c may be designed to have a larger particle size than the coating thickness of the second reflection reducing layer 103b, thereby inducing irregular reflection. That is, if the refractive indexes of the second reflection reducing layer 103b and the first scattering particles 103c are set to the same value, the first scattering particles 103c act as irregularities on the surface of the second reflection reducing layer 103b, . The reflectance can be reduced by the diffused reflection. That is, the reflectance is reduced, the visibility can be improved when the image is implemented in the transparent flexible display device, and a clearer transparent mode can be realized when the image is not implemented. Further, by using the second reflection reducing section 103 which does not require an adhesive and a support in a structure using an existing antireflection film, adhesive and support, a transparent flexible display device having a minimized thickness and flexibility can be obtained, .

8 is a diagram showing a second reflection reducing section of a transparent flexible display device according to a fourth embodiment of the present invention. This is a modification or addition of a part of the configuration of the second embodiment according to Figs. 4 to 6, and a description of the overlapping portions will be omitted.

The transparent flexible display device according to the fourth embodiment of the present invention may additionally include second scattering particles 103d in the second reflection reducing section 103. [ In the drawing, the second scattering particles 103d are disposed in the second reflection reducing layer 103b, but the present invention is not limited thereto. For example, the second scattering particles 103d may be disposed on the first reflection reducing layer 103a or on both of the plurality of layers.

As shown in FIG. 8, the second scattering particles 103d can be designed to have a smaller particle size than the coating thickness of the second reflection reducing layer 103b, thereby reducing the internal reflectance. That is, if the refractive index of the second reflection reducing layer 103b is set to be smaller than the refractive index of the second scattering particles 103d. The light incident on the second scattering particles 103d through the second reflection reducing layer 103b is refracted by the second scattering particles 103d having a larger refractive index and the internal reflectance can be reduced. When the internal reflection factor of the second reflection reduction section 103 is reduced in this manner, the reflectivity of the transparent flexible display device can be reduced. That is, the reflectance is reduced, the visibility can be improved when the image is implemented in the transparent flexible display device, and a clearer transparent mode can be realized when the image is not implemented. Further, by using the second reflection reducing section 103 which does not require an adhesive and a support in a structure using an existing antireflection film, adhesive and support, a transparent flexible display device having a minimized thickness and flexibility can be obtained, .

9 is a diagram showing a second reflection reducing section of a transparent flexible display device according to a fifth embodiment of the present invention. This is a modification or addition of a part of the configuration of the second embodiment according to Figs. 4 to 6, and a description of the overlapping portions will be omitted.

The transparent flexible display device according to the fifth embodiment of the present invention may additionally include third scattering particles 103e in the second reflection reducing section 103. [ In the drawing, the third scattering particles 103c are disposed in the second reflection reducing layer 103e, but the present invention is not limited thereto. For example, the third scattering particles 103e may be disposed on the first reflection reducing layer 103a or on both of the plurality of layers.

As shown in FIG. 9, the third scattering particles 103e may be formed as a double layer to change the path of the incident light. That is, light passing through the second reflection reducing layer 103b and incident on the third scattering particles 103e is changed in the optical path by the double layer structure of the third scattering particles 103e. By changing the light path through the third scattering particles 103e in this manner, the reflectance of the second reflection reducing section 103 is reduced, and the reflectivity of the transparent flexible display device can be reduced. That is, the reflectance is reduced, the visibility can be improved when the image is implemented in the transparent flexible display device, and a clearer transparent mode can be realized when the image is not implemented. Further, by using the second reflection reducing section 103 which does not require an adhesive and a support in a structure using an existing antireflection film, adhesive and support, a transparent flexible display device having a minimized thickness and flexibility can be obtained, .

10 and 11 are views showing a second reflection reducing portion of the transparent flexible display device according to the sixth embodiment of the present invention. This is a modification or addition of a part of the configuration of the second embodiment according to Figs. 4 to 6, and a description of the overlapping portions will be omitted.

The transparent flexible display device according to the sixth embodiment of the present invention may further include third scattering particles 103e and fourth scattering particles 103f in the second reflection reducing section 103. [ Although the third scattering particles 103e and the fourth scattering particles 103f are disposed on the second reflection reducing layer 103b, the third scattering particles 103e and the fourth scattering particles 103f are not limited thereto. For example, the third scattering particles 103e and the fourth scattering particles 103f may be disposed on the first reflection reducing layer 103a or on both of the plurality of layers.

Here, both the fourth scattering particles 103f and the third scattering particles 103e may be formed as a double layer. Further, the fourth scattered particles 103f and the third scattered particles 103e may have different refractive indices from each other. For example, the refractive index of the fourth scattering particles 103f may be larger or smaller than that of the third scattering particles 103e. The fourth scattering particles 103f and the third scattering particles 103e may have different sizes from each other. For example, the size of the fourth scattering particles 103f may be larger or smaller than that of the third scattering particles 103e.

Referring to FIGS. 10 and 11, it is possible to more efficiently change the path of the light incident on the fourth scattering particles 103f and the third scattering particles 103e having different sizes and refractive indices. That is, the light that has passed through the second reflection reducing layer 103b and is incident on the fourth scattering particle 103f is again incident on the third scattering particle 103e, and the internal light path is changed. In addition, the third scattering particles 103e and the fourth scattering particles 103f are set larger than the second reflection reducing layer 103b and act as irregularities on the surface of the second reflection reducing layer 103b to induce irregular reflection .

By using the fourth scattering particles 103f and the third scattering particles 103e of the double layer having different refractive indexes and sizes as described above, the reflectance of the second reflection reducing section 103 is reduced to reduce the reflectance of the transparent flexible display device Effect can be obtained. That is, the reflectance is reduced, the visibility can be improved when the image is implemented in the transparent flexible display device, and a clearer transparent mode can be realized when the image is not implemented. Further, by using the second reflection reducing section 103 which does not require an adhesive and a support in a structure using an existing antireflection film, adhesive and support, a transparent flexible display device having a minimized thickness and flexibility can be obtained, .

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 general inventive concept as defined by the appended claims and their equivalents. Will be clear to those who have knowledge of. Therefore, the scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention.

105: substrate 107: multi-buffer layer
120: Gate insulating film 140: Interlayer insulating film
145: passivation layer 171: planarization layer
173: inorganic layer 175: bank layer
180: anode electrode 190: organic light emitting layer
200: cathode electrode 170: first reflection reducing portion
103: second reflection reducing section 103a: first reflection reducing layer
103b: a second reflection reducing layer

Claims (14)

A substrate including a display portion and a transmissive portion;
A thin film transistor layer provided on the substrate;
A light emitting element layer provided on the thin film transistor layer; And
And a first reflection reducing part provided between the thin film transistor layer and the light emitting element layer,
Wherein the first reflection reducing portion is provided in the transmissive portion. The method according to claim 1,
Further comprising an opening region through which the substrate is exposed, wherein the first reflection reducing section is in contact with the substrate through the opening region. 3. The method of claim 2,
Further comprising a planarization layer disposed on the thin film transistor layer and an inorganic layer disposed on the planarization layer, wherein the planarization layer and the inorganic layer are disposed in a region overlapping the opening region. The method according to claim 1,
And a second reflection reducing section disposed on the bottom surface of the substrate. The method of claim 3,
Wherein the first reflection reduction unit comprises:
A first layer disposed on an upper surface of the substrate and a region overlapping the inorganic layer;
A second layer disposed on an upper surface of the first layer; And
And a third layer disposed on an upper surface of the second layer,
Wherein the first layer to the third layer have different refractive indices. 6. The method of claim 5,
Wherein the refractive index of the third layer decreases from the third layer toward the first layer. 6. The method of claim 5,
Wherein the first layer to the third layer are alternately laminated with an organic layer having a high refractive index and an inorganic layer having a low refractive index. 8. The method according to any one of claims 5 to 7,
Wherein the first reflection reduction portion is laminated in plural. 5. The method of claim 4,
Wherein the second reflection reduction unit comprises:
A first reflection reducing layer disposed on the substrate; And
And a second reflection reduction layer disposed on a lower surface of the first reflection reduction layer,
Wherein the first reflection reducing layer and the second reflection reducing layer are inorganic materials having different refractive indices. 10. The method of claim 9,
And the refractive index decreases from the second reflection reduction layer toward the first reflection reduction layer. 5. The method of claim 4,
And the second reflection reducing portion includes scattering particles. 12. The method of claim 11,
The scattering particles are divided into first scattering particles and second scattering particles having different refractive indices,
The size of the first scattering particles is larger than the size of the second scattering particles
Wherein the second reflection reducing portion includes at least one of the first scattering particles or the second scattering particles. 12. The method of claim 11,
The scattering particles have a double layer structure,
Third scattering particles and fourth scattering particles having different refractive indices,
And the second reflection reducing portion includes at least one of the three scattering particles or the fourth scattering particles. 14. The method according to any one of claims 9 to 13,
And the second reflection reduction portion is laminated in plural.

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