KR102167132B1 - Changeable polarizer and method for manufacturing the same, display comprising the same - Google Patents

Abstract

The variable light shielding plate according to an embodiment of the present invention includes a lower substrate having a lower electrode formed thereon, an upper substrate having an upper electrode facing the lower substrate, an electrochromic material injected between the lower substrate and the upper substrate, and the lower substrate And a spacer positioned between the upper substrate and supporting between the lower substrate and the upper substrate, wherein the spacer includes a first layer and a second layer positioned on the first layer, The glass transition temperature is characterized in that it is lower than the glass transition temperature of the first layer.

Description

Variable light shielding plate and its manufacturing method, and a display device including the same

The present invention relates to a variable shading plate, and more particularly, to a variable shading plate capable of maintaining a cell gap of the variable shading plate, a method of manufacturing the same, and a display device including the same.

Flat panel displays (FPDs) are increasing in importance with the development of multimedia. Accordingly, liquid crystal display (LCD), plasma display panel (PDP), field emission display (FED), organic light emitting display device (Organic Light Emitting Display Device), etc. Various flat panel displays are being put into practice. Among them, the liquid crystal display has superior visibility, low average power consumption and heat generation compared to the cathode ray tube, and the organic light emitting display device has a high-speed response speed with a response speed of 1 ms or less, and has a low power consumption. , Since it is self-luminous, there is no problem in the viewing angle, so it is drawing attention as a next-generation flat panel display device.

Recently, the development of transparent organic light emitting display devices has been actively made. A transparent organic light emitting display device may implement a transparent display by having a minimum light emitting portion and a transparent portion through which light can be transmitted as it is. The transparent display may be used as a transparent display or an opaque display according to a user's selection by having a variable light shielding plate that becomes transparent or opaque on the rear of the display.

1 and 2 are views showing a conventional variable light shielding plate. Referring to FIG. 1, in the conventional variable light shielding plate 10, the lower substrate 20 on which the transparent lower electrode 30 is formed and the upper substrate 40 on which the transparent upper electrode 50 are formed face each other, and the sealant 70 is It is formed by cementing. Between the lower electrode 30 and the upper electrode 50, an electrochromic material 60 that changes color by an electric field between the lower electrode 30 and the upper electrode 50 is formed, and the upper substrate 40 and the lower substrate Spacers 80 are provided to maintain a cell gap between (20).

Referring to FIG. 2, the above-described conventional variable light shielding plate 10 may be made of plastic flexible substrates. When the substrates are bent or bent, it becomes impossible to maintain the cell gap. Accordingly, the cell gap of the variable light shielding plate 10 is There is a problem in that the transmission and blocking rate of light become non-uniform due to non-uniformity.

The present invention provides a variable light shielding plate capable of maintaining a cell gap of the variable light shielding plate, a method of manufacturing the same, and a display device including the same.

In order to achieve the above object, the variable light shielding plate according to an embodiment of the present invention includes a lower substrate on which a lower electrode is formed, an upper substrate on which an upper electrode is formed facing the lower substrate, and is injected between the lower substrate and the upper substrate. An electrochromic material, and a spacer positioned between the lower substrate and the upper substrate and supporting between the lower substrate and the upper substrate, wherein the spacer includes a first layer and a second layer positioned on the first layer Including, but characterized in that the glass transition temperature of the second layer is lower than the glass transition temperature of the first layer.

The first layer is made of a spherical ball (ball) and the second layer is a layer surrounding the ball.

The spacer is characterized in that the ball spacer.

The first layer is a layer in contact with the lower electrode, and the second layer is on the first layer and is a layer in contact with the upper electrode.

The spacer is characterized in that the column spacer.

In addition, the method of manufacturing a variable light shielding plate according to an exemplary embodiment of the present invention includes forming a lower electrode on a lower substrate and forming an upper electrode on the upper substrate, as a first layer and a second layer on the lower electrode. Forming a spacer consisting of, wherein the glass transition temperature of the second layer is lower than the glass transition temperature of the first layer, bonding the lower substrate and the upper substrate with a sealant, the lower substrate and the And applying heat and pressure to an upper substrate to bond the spacer to the upper substrate on which the upper electrode is formed, and injecting an electrochromic material between the lower substrate and the upper substrate.

Heat applied to the upper and lower substrates is higher than the glass transition temperature of the second layer and lower than the glass transition temperature of the first layer.

In addition, the display device according to an exemplary embodiment of the present invention includes a display panel displaying an image and a variable light shielding plate positioned at a rear surface of the display panel to block or transmit light, wherein the variable light shielding plate includes a lower substrate on which a lower electrode is formed. And an upper substrate facing the lower substrate and on which an upper electrode is formed, an electrochromic material injected between the lower substrate and the upper substrate, and positioned between the lower substrate and the upper substrate, and between the lower substrate and the upper substrate. And a spacer to support, wherein the spacer includes a first layer and a second layer positioned on the first layer, wherein the glass transition temperature of the second layer is lower than the glass transition temperature of the first layer. do.

In an exemplary embodiment of the present invention, a variable light shielding plate and a display device including the same form a spacer including a second layer having a lower glass transition temperature than the first layer and adhere the spacers to the substrates, thereby forming a cell gap of the variable light shielding plate. There is an advantage in that the transmission and blocking rate of light can be made uniform by maintaining.

1 and 2 are views showing a conventional variable light shielding plate.
3 is a view showing a variable light shielding plate according to an embodiment of the present invention.
4 is a schematic diagram showing the operation of the variable light shielding plate according to an embodiment of the present invention.
5 is a view showing a spacer of a variable light shielding plate according to an embodiment of the present invention.
6 is a view showing a spacer of a variable light shielding plate according to another embodiment of the present invention.
7 is a view showing a method of manufacturing a variable light shielding plate according to an embodiment of the present invention for each process.
8 is an image showing a variable shading plate manufactured according to an embodiment of the present invention.
9 is an image showing a cross section of a variable shading plate manufactured according to an embodiment of the present invention.

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

3 is a view showing a variable light shielding plate according to an embodiment of the present invention, and FIG. 4 is a schematic diagram showing an operation of the variable light shielding plate according to an embodiment of the present invention.

Referring to FIG. 3, the variable light shielding plate 100 according to an embodiment of the present invention includes a lower substrate 110 on which a lower electrode 120 is formed, an upper substrate 130 on which the upper electrode 140 is formed, and an upper substrate. An electrochromic material injected into the cell gap formed by the spacer 170 between the upper substrate 130 and the lower substrate 110 and formed between the spacer 170 to support the spacer 170 and the lower substrate 110 ( 160).

The lower substrate 110 and the upper substrate 130 are made of a transparent and flexible plastic substrate, for example, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethylene etherphthalate ( poly ethylene ether phthalate), polycarbonate (PC), polyarylate, polyether imide, polyether sulfonate, polyimide or polyacrylate It may be made of any one or more selected from.

The lower electrode 120 and the upper electrode 140 respectively formed on the lower substrate 110 and the upper substrate 130 are transparent electrodes, for example, transparent conduction such as ITO (Indium Tin Oxide) and IZO (Indium Zinc Oxide). It can be made of material. In addition, the lower electrode 120 and the upper electrode 140 may further stack a metal such as copper or molybdenum on the above-described transparent conductive material. In addition, the lower substrate 110 and the upper substrate 130 are bonded together by a sealant, and a spacer 170 for maintaining a cell gap between the lower substrate 110 and the upper substrate 130 is positioned. The spacers 170 are adhered to the lower substrate 110 and the upper substrate 130, respectively, to maintain a cell gap between the lower substrate 110 and the upper substrate 130.

In addition, an electrochromic material 160 that changes color by an electric field is injected between the lower substrate 110 and the upper substrate 130 to constitute the variable light shielding plate 100 of the present invention. When a voltage is applied to the lower electrode 120 and the upper electrode 140 of the variable light shielding plate 100 configured as described above, the electrochromic material 160 displays black to block light. On the other hand, when no voltage is applied to the lower electrode 120 and the upper electrode 140, the electrochromic material 160 becomes transparent and transmits light. Therefore, it acts as a variable shading plate capable of transmitting or blocking light.

On the other hand, the electrochromic material 160 is a material that changes color by an electric field, for example, WO ₃ , NiOxHy, Nb ₂ O ₅ , TiO ₂ , MoO ₃ Among inorganic substances selected from among, or polymers containing repeating units derived from thiophene, carbazole, phenylene vinylene, acetylene, aniline, phenylenediamine and pyrrole monomers, viologen derivatives, phenothiazine and tetrathiafulvalene It contains selected organic matter. Since the electrochromic material exhibits black shielding and transparent transmission, when the electrochromic material is selected, it may be a material that changes from transparent to black or from black to transparent. If it is difficult to implement black with one color, black may be expressed with a combination of cyan, yellow, and deep red or a combination of red, green, and blue.

The electrochromic material described above is used by being dispersed in a transparent liquid electrolyte or used by forming a film together with a transparent solid electrolyte. As the liquid electrolyte, 1M LiOH aqueous solution, 1M LiClO ₄ aqueous solution, 1M KOH aqueous solution, etc. can be used, and as the solid electrolyte, Poly-AMPS, Poly(VAP), Modified PEO/LiCF ₃ SO ₃ etc. can be used. have. In particular, a solid electrolyte is a material capable of transmitting ions in a solid state, and is environmentally friendly because there is no problem such as leakage of liquid when manufacturing a device, and it has the advantage of being able to manufacture in any desired shape because it can be thinned. The electrochromic material dispersion in which the electrochromic material is dispersed in an electrolyte is mixed with an electrochromic material to prepare an electrochromic dispersion.

Referring to FIG. 4, the variable light shielding plate 100 including the electrochromic material 160 described above operates as follows. The variable light shielding plate 100 is positioned on the rear surface of the display panel DP, which is a transparent display that implements an image. At this time, the electrochromic material 160 of the variable shading plate 100 changes from transparent to black according to the application of voltage. If the user desires an opaque display, an electric field is formed between the lower electrode 120 and the upper electrode 140 so that the electrochromic material 160 displays black to block light. On the other hand, when a user desires a transparent display, if an electric field is not formed between the lower electrode 120 and the upper electrode 140, the electrochromic material 160 is itself transparent and transmits light. Accordingly, the display device according to the exemplary embodiment of the present invention may implement a transparent or opaque display by including the variable light blocking plate 100.

The variable light shielding plate according to an embodiment of the present invention described above includes a spacer supporting between an upper substrate on which an upper electrode is formed and a lower substrate on which a lower electrode is formed. In more detail, the spacer of the present invention will be described with reference to the following drawings. 5 is a view showing a spacer of a variable light shielding plate according to an embodiment of the present invention, and FIG. 6 is a view showing a spacer of a variable light shielding plate according to another embodiment of the present invention.

Referring to FIG. 5, the spacer 170 according to an embodiment of the present invention is formed between the upper electrode 140 and the lower electrode 120, and includes a first layer 171 and a second layer 172. . The spacer 170 is a column spacer, the first layer 171 is in contact with the lower electrode 120 and the second layer 172 is located on the first layer 171 and the upper electrode 140 It consists of a structure that makes contact with. In particular, in the spacer 170 of the present invention, the glass transition temperature of the second layer 172 contacting the upper electrode 140 is lower than the glass transition temperature of the first layer 171. Since the spacer 170 is basically formed directly on the lower electrode 120, the first layer 171 of the spacer 170 is adhered while making contact with the lower electrode 120. On the other hand, the second layer 172 formed on the first layer 171 of the spacer 170 is not adhered to the upper electrode 140 in contact. Accordingly, in the present invention, a second layer 172 having a lower glass transition temperature than the first layer 171 of the spacer 170 is formed, and the second layer ( The 172 may be melted and adhered to the upper electrode 140.

To this end, the spacer 170 of the present invention has a lower glass transition temperature of the second layer 172 than the first layer 171. As a method of lowering the glass transition temperature of the second layer 172, a material having a lower glass transition temperature than the first layer 171 is used, or the same material as the first layer 171 is used, but a plasticizer or methyl group is used. The glass transition temperature can be lowered by adding more. However, a method of forming the second layer 172 to have a low glass transition temperature is not limited thereto, and any other known method may be used.

Meanwhile, referring to FIG. 6 showing a spacer 170 according to another embodiment of the present invention, the shape of the spacer 170 may be formed of a ball spacer 170, unlike the column spacer 170 described above. . In the case of the ball spacer 170, the first layer 171 may be formed of a spherical ball, and the second layer 172 may be formed of a layer surrounding the ball. In the case of the ball spacer 170, the material and properties of the first layer and the second layer of the column spacer 170 are the same. That is, the second layer 172 having a lower glass transition temperature than the first layer 171 of the ball spacer 170 is formed, and the second layer 172 is formed through a heating process after bonding the upper and lower substrates to be described later. May be melted and adhered to the upper electrode 140 and the lower electrode 120, respectively.

The above-described spacer may be made of a resist of a negative or positive type, and includes, for example, a binder polymer, a monomer, a photoinitiator, a dye, and a plasticizer. The binder polymer imparts film-forming properties to the resist layer, and in the case of an alkali developing type, develops or peels properties with an alkaline aqueous solution. The monomer and the photopolymerization initiator cause a crosslinking reaction by radical polymerization by light from an ultraviolet exposure group. As a result, the resist layer is cured and does not dissolve in the developer, and a negative type image is formed. In addition, in addition to the basic composition, a number of additives are contained, thereby satisfying various characteristics required for the resist.

In more detail, as the binder polymer, a linear copolymer of radically polymerizable monomers such as acrylic or styrene is used to impart thermal crosslinkability and thermal fluidity to the resist layer. In the case of the alkali developing type, a copolymer of a monomer having a carboxyl group is used, and it exhibits a function as a surfactant similar to soap in a weakly alkaline developer. The binder polymer emulsifies another resist component insoluble in water, and the resist component is dissolved in the developer in an emulsion state.

The monomer is usually used in combination with several types of radically polymerizable compounds having 1 to 3 (meta)Acrylo groups in the molecule. In order to form a three-dimensional crosslinking, two to three functional monomers are the center, but a monofunctional monomer is sometimes added in order to improve the flexibility or peeling speed of the cured resist. In addition, in order to obtain sufficient mechanical strength (for example, tenting strength), a polyfunctional monomer having 4 or more functions may be used. Although the alkali ester-based monomer has higher sensitivity than the meta-acrylic ester-based, the chemical resistance tends to decrease somewhat. The monomer also has a function as a plasticizer of the binder polymer, and may impart flexibility at room temperature and fluidity during heating during lamination. Currently, several types of monomers are used, some of which are exemplified below.

The photopolymerization initiator generally has a sufficient spectral sensitivity in a wavelength range of 300 to 400 nm, and is not sensitive to visible light of 450 nm or more. This is because ultraviolet rays of 300 nm or less are absorbed by a polyester mask film or a polyethylene carrier film and do not reach the resist layer, and when they are exposed to visible light of 450 nm or more, handling in a UV blocking room such as a yellow room becomes impossible. Representative compositions are illustrated below. The photopolymerization initiator is a component that controls the sensitivity distribution of the resist, and an optimal component is selected according to the purpose of use of the dry film resist.

The resist layer is colored with a basic dye. Blue or green colors are common, but some red colors are also used. In order to facilitate the inspection of the cured pattern, a dye that develops in ultraviolet rays is added, but there are cases where a fading dye is used for the same purpose. Representative examples are shown below.

In order to impart sufficient adhesion to the resist layer and the copper surface, and to suppress lifting or liquid penetration in etching or plating processes, a copper surface adhesive is added. In the case of the alkali developing type, since the carboxyl group in the binder polymer imparts coplanar adhesion, there is a case where a separate coplanar adhesion agent is not added.

The plasticizer is added to lower the glass transition temperature of the binder polymer by the monomer. Representative plasticizers are shown below.

Hereinafter, a method of manufacturing a variable light shielding plate according to an embodiment of the present invention described above will be described. 7 is a view showing a method of manufacturing a variable light shielding plate according to an embodiment of the present invention for each process.

Referring to FIG. 7A, a lower electrode 120 is formed by depositing a transparent conductive material on the lower substrate 110 made of plastic. Subsequently, after applying and curing a negative type first resist, a second resist having a lower glass transition temperature than the first photoresist is applied, cured, and patterned to laminate the first layer 171 and the second layer 172 Formed spacers 170 are formed.

Next, referring to (b), the upper electrode 140 is formed by depositing a transparent conductive material on the upper substrate 130 made of plastic. In addition, after the sealant 150 is applied to the upper substrate 130 and bonded to the lower substrate 110, the electrochromic material 160 is mixed with an electrolyte, injected, and sealed.

Next, referring to (c), the second layer 172 of the spacer 170 is melted by applying pressure to the upper substrate 130 and the lower substrate 110 and simultaneously applying heat. At this time, the applied heat applies a temperature equal to or higher than the glass transition temperature of the second layer 172 but a temperature lower than the glass transition temperature of the first layer 171. In addition, the second layer 172 of the spacer 170 is adhered to the upper electrode 140 by applying heat for a period of time not to completely melt the second layer 172. Thus, a variable light shielding plate according to an embodiment of the present invention is manufactured.

Hereinafter, the variable light shielding plate of the present invention will be described in detail in the following experimental examples. However, the following experimental examples are only illustrative of the present invention, and the present invention is not limited to the following experimental examples.

<Example>

ITO was formed to a thickness of 1500 Å on the PET substrate, and 6000 Å of copper and 3000 Å of molybdenum were further formed to prepare upper and lower electrodes on the upper and lower substrates, respectively. At this time, the width of the electrodes was 40 μm, and the pitch of the electrodes was 1 mm. Spacers having different glass transition temperatures were patterned on the lower electrode to form and adhered with a sealant. In addition, an 18-inch variable light shielding plate was manufactured by mixing and injecting an electrochromic material representing transparency and black into a lithium electrolyte.

Nine measurement positions of the prepared variable shading plate were determined, and transmittance, shading rate, and color coordinate were measured, respectively, and are shown in Table 1 below. In addition, the manufactured variable shading plate is shown as an image in FIG. 9, and a cross-sectional image of the manufactured variable shading plate is shown in FIG. 10.

#

Measuring position One 2 3 4 5 6 7 8 9 Transmittance (%) 74.21 72.01 71.99 71.67 71.63 69.84 74.52 72.86 73.81 Shading rate (%) 86.46 86.50 87.01 86.40 85.56 86.36 85.89 84.12 85.69 Color coordinates
(x,y)
Transparency 0.3020.327 0.300
0.327 0.298 0.325 0.303 0.329 0.304 0.330 0.300 0.327 0.303 0.329 0.305 0.331 0.303 0.329 Shading 0.192
0.161 0.192
0.161 0.189
0.157 0.194
0.166 0.196
0.171 0.193
0.166 0.193
0.165 0.200
0.180 0.194
0.167

Referring to Table 1, the average transmittance in each region of the variable shading plate manufactured according to the embodiment of the present invention is 73%, indicating a deviation of about 2.3%, and the average shading rate is 86%, indicating a deviation of about 1.4%. It could be used as a variable shading plate. In addition, there was no problem in performing the function of the variable light-shielding plate in the color coordinates of transparent and light-shielding. Meanwhile, referring to FIGS. 9 and 10, it was confirmed that a spacer was adhered to each of the substrates in the variable light shielding plate manufactured according to the exemplary embodiment of the present invention.

As described above, in the variable light shielding plate and the display device including the same according to an embodiment of the present invention, a spacer including a second layer having a lower glass transition temperature than the first layer is formed and the spacers are adhered to the substrates. There is an advantage that the light transmission and blocking rate can be made uniform by maintaining the cell gap of.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above is in other specific forms without changing the technical spirit or essential features of the present invention by those skilled in the art. It will be appreciated that it can be implemented. Therefore, the embodiments described above are illustrative in all respects and should be understood as non-limiting. In addition, the scope of the present invention is indicated by the claims to be described later rather than the detailed description. In addition, all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

100: variable shading plate 110: lower substrate
120: lower electrode 130: upper substrate
140: upper electrode 150: sealant
160: electrochromic material 170: spacer

Claims (9)

A lower substrate having a lower electrode and an upper substrate facing the lower substrate and having an upper electrode;
An electrochromic material injected between the lower substrate and the upper substrate; And
And a spacer positioned between the lower substrate and the upper substrate and supporting between the lower substrate and the upper substrate,
The spacer includes a first layer and a second layer positioned on the first layer, wherein the glass transition temperature of the second layer is lower than the glass transition temperature of the first layer,
The second layer is directly adhered to at least one of the lower electrode and the upper electrode,
The second layer includes the same binder polymer as the first layer, a monomer, a photopolymerization initiator, and a dye, and the second layer is further added with a plasticizer or a methyl group to lower the glass transition temperature,
The binder polymer includes a styrene-based, and the monomer includes a multifunctional monomer.
The method of claim 1,
The first layer is made of a spherical ball (ball), the second layer is a variable light shielding plate, characterized in that the layer surrounding the ball.
The method of claim 2,
The spacer is a variable light shielding plate, characterized in that the ball spacer.
The method of claim 1,
The first layer is a layer in contact with the lower electrode, and the second layer is a layer on the first layer and in contact with the upper electrode.
The method of claim 4,
The spacer is a variable light shielding plate, characterized in that the column spacer.
Forming a lower electrode on a lower substrate and forming an upper electrode on the upper substrate;
Forming a spacer comprising a first layer and a second layer on the lower electrode, wherein the glass transition temperature of the second layer is lower than the glass transition temperature of the first layer;
Bonding the lower substrate and the upper substrate with a sealant;
Bonding the spacer and the upper substrate on which the upper electrode is formed by applying heat and pressure to the lower substrate and the upper substrate; And
Injecting an electrochromic material between the lower substrate and the upper substrate,
The second layer is directly adhered to at least one of the lower electrode and the upper electrode,
The second layer includes the same binder polymer as the first layer, a monomer, a photopolymerization initiator, and a dye, and the second layer is further added with a plasticizer or a methyl group to lower the glass transition temperature,
The binder polymer includes a styrene-based, and the monomer includes a polyfunctional monomer.
The method of claim 6,
Heat applied to the upper substrate and the lower substrate is higher than the glass transition temperature of the second layer and lower than the glass transition temperature of the first layer.
A display panel that displays an image; And
A variable light shielding plate positioned at the rear of the display panel to block or transmit light,
The variable shading plate,
A lower substrate on which a lower electrode is formed, an upper substrate on which an upper electrode is formed facing the lower substrate, an electrochromic material injected between the lower substrate and the upper substrate, and the lower substrate positioned between the lower substrate and the upper substrate And a spacer supporting between the upper substrate and the spacer, wherein the spacer includes a first layer and a second layer positioned on the first layer, wherein the glass transition temperature of the second layer is Lower than the temperature,
The second layer is directly adhered to at least one of the lower electrode and the upper electrode,
The second layer includes the same binder polymer as the first layer, a monomer, a photopolymerization initiator, and a dye, and the second layer is further added with a plasticizer or a methyl group to lower the glass transition temperature,
The binder polymer includes a styrene system, and the monomer includes a polyfunctional monomer. delete

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