KR20090065094A - Optical member for display apparatus and filter for display apparatus having the same - Google Patents

Abstract

An optical member for a display device and a filter for a display device including the same are provided to lower reflectance by performing not only an anti-reflection function by optical interference but also an absorbing function of an outer light. An optical member(100) for a display device includes a first member(110), a first coating layer, and a second coating layer. The first member is made of transparent resin material. The first coating layer(120) is formed on one surface of the first member, and has a first refractive index. The second coating layer(140) is formed on the first coating layer, includes a carbon black particle(131), and has a second refractive index of a size lower than the first refractive index.

Description

Optical member for display apparatus and filter for display apparatus including same {Optical member for display apparatus and filter for display apparatus having the same}

The present invention relates to an optical member for a display device and a filter for a display device including the same, and more particularly, an optical member for a display device that can increase contrast ratio of a display by lowering reflectance of external light and increasing absorption efficiency. The present invention relates to a filter for a display device including the same.

As the modern society is highly informationized, image display-related parts and devices have been remarkably advanced and disseminated. Among them, display apparatuses for displaying images are widely used for television apparatuses, monitor apparatuses of personal computers, and the like, and thinning is progressing at the same time as these displays are enlarged.

In general, a plasma display panel (PDP) device is in the spotlight as a next-generation display device because it can satisfy both an enlargement and a thinning at the same time as a cathode ray tube (CRT) representing a conventional display device.

The PDP apparatus displays an image using a gas discharge phenomenon, and is excellent in various display capabilities such as display capacity, brightness, contrast, afterimage, viewing angle, and the like. In addition, the PDP device is easier to be enlarged than other display devices, and is considered as a thin light emitting display device having the most suitable characteristics as a high quality digital television in the future.

The PDP device generates a discharge in the gas between the electrodes by a direct current or an alternating current voltage applied to the electrode, and excites the phosphor by the radiation of ultraviolet rays, which emits light.

However, due to its driving characteristics, the PDP device has a high emission amount of electromagnetic waves and near infrared rays, high surface reflection of the phosphor, and color purity of the PDP device due to the orange light emitted from the encapsulated helium (He) or xenon (Xe), which does not reach the cathode ray tube. There is this. Electromagnetic waves and near-infrared rays generated by PDP devices may have a harmful effect on the human body and may cause malfunctions of precision devices such as cordless phones or remote controls. In order to use such a PDP apparatus, it is required to suppress the emission of electromagnetic waves and near-infrared rays emitted from the PDP apparatus below a predetermined value.

To this end, there is a method of mounting the electromagnetic shielding plate on the front of the display portion of the display, and the electromagnetic shielding plate used as the front plate is required not to degrade the transparency of the display display screen in addition to the function of shielding the electromagnetic waves.

However, the PDP requires not only electromagnetic shielding but also various functions such as near-infrared shielding, reduced reflected light, improved color purity, and improved contrast ratio. The PDP filter is a structure in which functional layers such as an electromagnetic shielding layer, a near infrared shielding layer, a color correction layer, an external light shielding layer, an antireflection layer, or a composite layer that simultaneously performs two or more of these functions are stacked. At the same time, a lot of efforts are being made to simplify and economically improve the manufacturing process.

The antireflection layer is attached to the front surface of the filter, and a technique for forming the antireflection layer includes a wet coating method in which a solution is applied on a film and then repeatedly dried, and a dry method by sputtering and vapor deposition. The former is difficult to laminate while precisely reproducing the thickness of the film, and the latter has a problem of high manufacturing cost and low productivity because of high precision but using vacuum. In order to solve this problem, it is advantageous to reduce the number of layers for expressing the antireflection function by optical interference as much as possible and to apply wet coating. However, to realize this, a material having a sufficiently low refractive index capable of wet coating is required.

As such a material, it has been studied to use a silicone resin and hollow silica fine particles having an average particle size of 5 to 2000 nm and a cavity formed therein. However, hollow silica is an expensive material, which increases the manufacturing cost and the reflection color of the filter. This red color has a problem in that the image quality of the display is lowered.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical member for a display device that can lower the reflectance by exhibiting a function of preventing reflection by optical interference as well as absorbing external light.

It is another object of the present invention to provide an optical member for display having low manufacturing cost and achromatic color.

Another object of the present invention is to provide a filter for a display device including the optical member as described above, which can further increase the absorption efficiency of external light.

Technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

An optical member for a display device according to an aspect of the present invention is formed on a first substrate made of a transparent resin material, a first coating layer formed on one surface of the first substrate, and having a first refractive index, and formed on the first coating layer and carbon black. And a second coating layer including particles and having a second refractive index having a size smaller than the first refractive index.

The present invention is characterized in that the carbon black particles are dispersed in the second coating layer so as to correspond to the entire surface of the first coating layer to form a carbon black film.

The present invention is also characterized in that the carbon black film has a thickness of less than 10 nm.

In the optical member for a display device according to another aspect of the present invention, the carbon black film is formed by arranging spherical or elliptical carbon black particles in a single layer.

The present invention also includes at least one resin selected from the group consisting of polyethylene terephthalate (PET), triacetyl cellulose (TAC), polymethylmethacrylate (PMMA) and polyvinyl alcohol (PVA). It is characterized by.

The present invention is also characterized in that the adhesive layer (PSA) is disposed on the other surface of the first substrate.

In the optical member for a display device according to another aspect of the invention the refractive index of the first coating layer is 1.8 to 2.5 and the thickness is 5nm to 50nm, the refractive index of the second coating layer is 1.3 to 1.5 and the thickness is 50nm to 150nm. .

The present invention is also characterized in that the first coating layer comprises at least one oxide selected from the group consisting of titanium oxide (TiO 2), indium tin oxide (ITO), antimony oxide (Sb 2 O 3) and zinc oxide (ZnO).

The present invention is also characterized in that the second coating layer comprises at least one resin selected from the group consisting of silica resins and fluorine resins.

The optical member for a display device according to another aspect of the present invention further includes a dye in which the second coating layer selectively absorbs the wavelength according to the wavelength of light. The dye includes at least one of cyanine-based, anthraquinone-based, naphthoquinone-based, phthalocyanine-based, naphthalocyanine-based, dimonium-based, nickel dithiol-based, azo-based, stryl-based, phthalocyanine-based and methine-based dyes. .

In the optical member for a display device according to another aspect of the present invention, the first coating layer and the second coating layer are alternately stacked two to four times on the first substrate.

The present invention is also characterized in that the reflectance of the optical member for display device is 2% or less.

The present invention is also characterized in that the optical member for display device is achromatic.

An optical member for a display device according to another aspect of the present invention includes a second substrate made of a transparent resin material and a third coating layer formed on one surface of the second substrate and including carbon black particles and a polymer resin.

The third coating layer includes at least one polymer resin selected from the group consisting of acrylic resins, urethane resins, epoxy resins, silica resins, and fluorine resins.

The carbon black particles are dispersed in the third coating layer to correspond to the entire surface of the second substrate to form a carbon black film, and the carbon black film has a thickness of less than 10 nm.

The present invention is also characterized in that the adhesive layer (PSA) is disposed on the other surface of the second substrate.

A display device filter according to an aspect of the present invention includes a filter base having an external light shielding film including a substrate and an external light shielding pattern formed on one surface of the substrate, and an optical member for display device formed on one surface of the filter base. . The optical member for the display device includes: i) a first substrate made of a transparent resin material, ii) a first coating layer formed on one surface of the first substrate and having a first refractive index, and iii) a carbon black formed on the first coating layer. And a second coating layer including particles and having a second refractive index having a size smaller than the first refractive index. The base material included in the filter base may be a transparent resin material as in the first base material, but a glass substrate such as semi-tempered glass may be used.

The external light shielding pattern is a stripe pattern having a wedge-shaped, rectangular, trapezoidal or U-shaped cross-sectional shape, and includes carbon black.

According to another aspect of the present invention, a filter for a display device includes a filter base having an external light shielding film including a substrate and an external light shielding pattern formed on one surface of the substrate, and an optical member for display device formed on one surface of the filter base. do. The optical member for a display device includes: i) a second substrate made of a transparent resin material; ii) a third coating layer formed on one surface of the first substrate and comprising carbon black particles and a polymer resin.

The display device to which the optical member for the display device and the filter for the display device are applied according to the present invention include a plasma display panel (PDP) device, an organic light emitting diode (OLED) device, and an LCD that implement RGB with pixels of a grid pattern. (Liquid Crystal Display) device or FED (Field Emission Display) device. Hereinafter, the present invention will be described using a PDP device and a PDP filter used for convenience of description, but the present invention is not limited thereto and may be applied to the aforementioned various display devices and filters for display devices used therein.

The optical member for a display device according to the present invention can exhibit a low refractive index because it can exhibit a low refractive index and absorb light.

In addition, the optical member for a display device according to the present invention does not use hollow silica can reduce the manufacturing cost. In addition, since the reflection color is achromatic, the image quality is excellent by not changing the color of the display, and the appearance of the display can be improved because the color of the optical member itself is achromatic.

The filter for a display device according to the present invention is excellent in absorption efficiency of external light and can increase the contrast ratio in the bright room of the display, thereby improving visibility.

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

1 is a cross-sectional view of an optical member for a display apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the optical member 100 for a display device includes a first substrate 110, a first coating layer 120, a second coating layer 140, and an adhesive layer 150. The second coating layer 140 includes a carbon black film 130 made of carbon black particles 131 and a polymer resin 142.

The first substrate 110 has a material of a transparent resin, at least selected from the group consisting of polyethylene terephthalate (PET), triacetyl cellulose (TAC), polymethyl methacrylate (PMMA) and polyvinyl alcohol (PVA) It is characterized by including one resin.

The first coating layer 120 is formed on one surface of the first substrate 110, and the adhesive layer 150 is formed on the other surface of the first substrate 110. However, the present invention is not limited thereto, and the adhesive layer 150 may be excluded from the configuration of the present invention.

The first coating layer 120 has a higher refractive index than the second coating layer 140 and is thin. Optical properties of the optical member 100 for a display device may be controlled by adjusting the refractive index and the thickness of the first coating layer 120 and the second coating layer 140. That is, the light incident from the outside causes some refraction and partial reflection on the interface between the first coating layer 120 and the second coating layer 140 and the interface between the first coating layer 120 and the first substrate 110. At this time, if the mutual interference occurs due to the phase difference of the light reflected from the different boundary surface, the amount of light reflected by the external light toward the viewer is reduced to increase the contrast ratio of the screen.

Accordingly, the degree of antireflection may vary according to the refractive index and the thickness range of the first coating layer 120 and the second coating layer 140. The refractive index of the first coating layer 120 is 1.8 to 2.5, preferably about 2.0, and the refractive index of the second coating layer 140 is 1.3 to 1.5, preferably about 1.46. In addition, the thickness of the first coating layer 120 is 5nm to 50nm, the thickness of the second coating layer 140 is 50nm to 150nm. If the thickness of the first coating layer 120 is not optimized and is too thick or too thin, the reflectance is increased, so that the desired anti-reflection performance is not exhibited. In addition, when the thickness of the second coating layer 140 is too thick or too thin, a predetermined reflectance cannot be obtained. As the refractive index of the first coating layer 120 is higher and the refractive index of the second coating layer 140 is lower, antireflection performance may increase.

The first coating layer 120 may include titanium oxide, indium tin oxide (ITO), antimony oxide (Sb 2 O 3), and zinc oxide (ZnO). The above materials have high refractive index and transparent properties. The oxides may be used alone or in combination of two or more thereof. In addition, when the first coating layer and the second coating layer are stacked a plurality of times, the type of oxide used in each of the first coating layers may be the same or different.

Resin 142 of the second coating layer is characterized in that it comprises silicon oxide or fluorine-based resin, or a combination thereof. The above materials have a lower refractive index than the first coating layer 120 and have electrical insulation properties.

A plurality of carbon black particles 131 are included in the second coating layer 140. Conventionally, hollow silica was used, but manufacturing cost was disadvantageous. In the present invention, by using the carbon black it is possible to lower the manufacturing cost, and to add a light absorption function, it is possible to lower the reflectance compared to the conventional optical member.

The carbon black particles 131 are dispersed in the second coating layer 140 to correspond to the entire surface of the first coating layer 120 to form a carbon black film 130. Since the thickness H of the carbon black film 130 is smaller than 10 nm, it may not affect the transmission of the image emitted from the panel. That is, the carbon black particles 131 are disposed in a form of a thin carbon black film without being randomly distributed in the second coating layer 140. The carbon black particles 131 have a spherical or oval shape and are arranged in a single layer. However, the present invention is not limited thereto, and the carbon black particles may be of different kinds. In addition, the carbon black film 130 may be formed by stacking carbon black particles without forming a single layer within a range in which the thickness of the carbon black film 130 is smaller than 10 nm.

The optical member 100 for the display device includes carbon black particles 131 and has a reflectance of 2% or less. In addition, the optical member 100 for the display device may absorb external light when the power of the display device is turned off, so that the reflection color can be implemented in achromatic color, thereby improving the appearance of the display.

The polymer resin 142 of the second coating layer further includes a pigment that selectively absorbs the wavelength according to the wavelength of light, so that the optical member 100 may perform not only an antireflection function but also a color correction function. The dye includes at least one of cyanine, anthraquinone, naphthoquinone, phthalocyanine, naphthalocyanine, dimonium, nickel dithiol, azo, stryl, phthalocyanine and methine dyes.

In addition, although not shown, the optical member for a display device according to another aspect of the present invention may be alternately alternately stacked two to four times on the substrate and the first coating layer and the second coating layer. Compared with a structure in which the first coating layer and the second coating layer are laminated only once, the lamination of the first coating layer and the second coating layer may be performed without increasing the light transmittance of the film and at the same time, further increasing the effect of preventing the reflection of external light. Therefore, the optical member for a display device of the present invention may have a structure in which the first coating layer and the second coating layer are alternately stacked two to four times.

The adhesive layer 150 may include a copolymer such as a perfluoro alkyl ether, a vinyl ether, a vinyl ester, or the like. In addition, the adhesive layer 150 may further include a polyisocyanate, a melamine compound, an epoxy resin compound, and the like.

Hereinafter, an optical member for a display apparatus according to another exemplary embodiment of the present invention will be described, and descriptions overlapping with the aforementioned contents will be omitted.

2 is a cross-sectional view of an optical member for a display apparatus according to another exemplary embodiment of the present invention.

Referring to FIG. 2, the optical member 200 for a display device includes a second substrate 210, a third coating layer 240, and an adhesive layer 250. The third coating layer 240 includes a carbon black film 230 made of carbon black particles 231 and a polymer resin 220.

The third coating layer 240 is formed on one surface of the second substrate 210, and the adhesive layer 250 is formed on the other surface of the second substrate 210.

The second substrate 210 is a transparent resin substrate, and like the first substrate 110 described above, polyethylene terephthalate (PET), triacetyl cellulose (TAC), polymethyl methacrylate (PMMA), and poly Vinyl alcohol (PVA) is characterized in that it comprises at least one resin selected from the group consisting of.

The polymer resin 220 of the third coating layer includes at least one polymer resin selected from the group consisting of an acrylic resin, a urethane resin, an epoxy resin, a silica resin, and a fluorine resin.

The carbon black particles 231 are dispersed in the third coating layer 240 to correspond to the entire surface of the second substrate 210 to form a carbon black film 230, and the carbon black film 230 has a thickness of 10 It is characterized by smaller than nm.

The optical member 200 for a display device according to the present exemplary embodiment includes a carbon black film 230 capable of shielding external light due to absorption of light in the third coating layer 240, thereby providing a function of reflecting and absorbing external light even in a single layer. Can be done.

Hereinafter, a filter for a display device according to an exemplary embodiment of the present invention will be described.

3 is a cross-sectional view of a filter for a display device according to an embodiment of the present invention.

Referring to FIG. 3, the filter 300 for a display device includes an optical member 310 for a display device and a filter base. The filter base may include an electromagnetic wave shielding film 320, an external light shielding film 330, and an adhesive layer 340, but may further include other functional films such as a near infrared shielding film and a color correction film, although not shown.

The adhesive layer 340 is for attaching the panel assembly and the filter 300 for the display device. Panel incident light 390 incident from the panel assembly passes through the functional layers in filter 300 and then displays the image toward the viewer. The display device filter 300 reflects and absorbs external environmental light 380 such as direct sunlight, fluorescent lamps, incandescent lamps, and the like, thereby preventing display quality degradation of the display.

The optical member 310 for the display device includes a first substrate 311, a first coating layer 312, and a second coating layer 315 made of a transparent resin material, and the second coating layer 3150 may include carbon black particles. It consists of a carbon black film 313 and a resin 314. Since the optical member 310 for the display device is the same as that of FIG. 1, redundant descriptions thereof will be omitted.

Although not shown, the filter 300 for a display device according to another exemplary embodiment of the present invention may use the one shown in FIG. 2 as a display optical member.

Meanwhile, the electromagnetic shielding film 320 which is a part of the filter base serves to block electromagnetic waves generated from the panel assembly of the display device. In order to shield the electromagnetic waves, the surface of the display needs to be covered with a highly conductive object. As the electromagnetic wave shielding layer 320 for shielding electromagnetic waves according to an embodiment of the present invention, a multilayer transparent conductive film including a conductive mesh film or a metal thin film and a high refractive index transparent thin film may be used.

As the conductive mesh film, generally, a metal mesh ground or a metal coating on a mesh of synthetic resin or metal fiber can be used. As a material of the metal which comprises a conductive mesh film, if the metal which is excellent in electroconductivity and workability, such as copper, chromium, nickel, silver, molybdenum, aluminum, can be used, for example.

In addition, the multilayer transparent conductive film may be a high refractive transparent thin film represented by indium tin oxide (ITO) to shield the electromagnetic waves. Examples of the multilayer transparent conductive film include a multilayer thin film in which metal thin films such as gold, silver, copper, platinum, and palladium are alternately stacked with high refractive index transparent thin films such as indium oxide, ditin oxide, and zinc oxide.

The external light shielding film 330, which is part of the filter base, includes a substrate 322 and an external light shielding pattern 334 formed on one surface of the substrate 322.

The external light shielding pattern 334 is made of a wedge-shaped stripe, that is, a triangular prism structure having a plurality of intaglio three-dimensional shapes, but the present invention is not limited thereto. The external light shielding pattern may be embossed or intaglio. It can have a two-dimensional or three-dimensional shape. The external light shielding pattern 334 is formed by filling a light absorbing material such as carbon black in an intaglio pattern having a predetermined cross-sectional shape. In the present embodiment, the external light shielding pattern 334 has a wedge-shaped cross section, but may have a rectangular, trapezoidal, or U-shaped cross section.

In the present embodiment, the external light shielding pattern 334 has a wedge-shaped bottom surface of the external light shielding pattern 334 parallel to one surface of the substrate 332, but the panel assembly is not limited thereto. That is, the wedge-shaped bottom surface of the external light shielding pattern 334 parallel to one surface of the substrate 332 may face the viewer, and the external light shielding pattern may be formed on both surfaces of the substrate.

The substrate 332 is a plate-like support made of a transparent material that transmits visible light, and may include polyethylene terephthalate (PET), acrylic, polycarbonate (PC), urethane acrylate (Urethane Acrylate), It may be made of polyester, epoxy acrylate, brominated acrylate, polyvinyl chloride (PVC), and the like.

The external light shielding film 330 absorbs external light to prevent external environment light 380 from entering the panel assembly and totally reflects the panel incident light 390 emitted from the panel assembly toward the viewer. Thus, a high transmittance to visible light and a high contrast ratio can be obtained. In addition, the filter 300 for display device according to the present invention is excellent in the light absorption efficiency because the absorption of the external light by the external light shielding film 330 and the carbon black film 313 is made of a double.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

1 is a cross-sectional view of an optical member for a display apparatus according to an embodiment of the present invention.

2 is a cross-sectional view of an optical member for a display apparatus according to another exemplary embodiment of the present invention.

3 is a cross-sectional view of a filter for a display device according to an embodiment of the present invention.

[Description of Major Symbols in Drawing]

100, 200: optical member for display device

110, 210, 311: substrate 120: first coating layer

130 and 230: carbon black film 131 and 231: carbon black particles

140: second coating layer 142, 220: polymer resin

150, 250: adhesive layer 240: third coating layer

300: filter for display device 310: optical member for display device

312: first coating layer 313: carbon black film

314: polymer resin 315: second coating layer

320: electromagnetic shielding film 330: external light shielding film

332: base material 334: external light shielding pattern

340: adhesive layer 380: external ambient light

390: panel incident light

Claims (18)

A first substrate made of a transparent resin material; A first coating layer formed on one surface of the first substrate and having a first refractive index; And A second coating layer formed on the first coating layer and including carbon black particles, the second coating layer having a second refractive index smaller than the first refractive index; Optical member for display device comprising a. The method of claim 1, The carbon black particles are dispersed in the second coating layer so as to correspond to the entire surface of the first coating layer to form a carbon black film optical member for a display device. The method of claim 2, The thickness of the carbon black film is less than 10nm optical member for display device. The method of claim 3, The carbon black film is an optical member for a display device, characterized in that the spherical or oval carbon black particles are formed in a single layer arrangement. The method of claim 1, The first substrate comprises at least one resin selected from the group consisting of polyethylene terephthalate (PET), triacetyl cellulose (TAC), polymethyl methacrylate (PMMA) and polyvinyl alcohol (PVA) Optical member for display device. The method of claim 1, An adhesive layer (PSA) is disposed on the other surface of the first substrate, the optical member for display device. The method of claim 1, The refractive index of the first coating layer is 1.8 to 2.5, the thickness is 5nm to 50nm, the refractive index of the second coating layer is 1.3 to 1.5 and the thickness is 50nm to 150nm optical member for the display device. The method of claim 1, The first coating layer includes at least one oxide selected from the group consisting of titanium oxide (TiO 2), indium tin oxide (ITO), antimony oxide (Sb 2 O 3), and zinc oxide (ZnO). . The method of claim 1, The second coating layer is an optical member for a display device, characterized in that at least one resin selected from the group consisting of silica resin and fluorine resin. The method of claim 1, The second coating layer further comprises a pigment for selectively absorbing wavelengths according to the wavelength of light. The method of claim 1, And the first coating layer and the second coating layer are alternately stacked two to four times on the first substrate. The method of claim 1, The reflectance of the optical member for display device is 2% or less, the optical member for display device. The method of claim 1, The optical member for display device is achromatic color, characterized in that the display member optical member. 2nd base material of transparent resin material; And A third coating layer formed on one surface of the second substrate and including carbon black particles and a polymer resin; Optical member for display device comprising a. The method of claim 14, The third coating layer is an optical member for a display device comprising at least one polymer resin selected from the group consisting of acrylic resins, urethane resins, epoxy resins, silica resins and fluorine resins. The method of claim 14, The carbon black particles are dispersed in the third coating layer so as to correspond to the entire surface of the second substrate to form a carbon black film, and the thickness of the carbon black film is less than 10 nm. A filter base having an external light shielding film including a substrate and an external light shielding pattern formed on one surface of the substrate; And A display device filter comprising a display device optical member formed on one surface of the filter base, wherein the display device optical member, i) a first base material of transparent resin material; ii) a first coating layer formed on one surface of the first substrate and having a first refractive index; And iii) a second coating layer formed on the first coating layer and comprising carbon black particles, the second coating layer having a second refractive index having a size smaller than the first refractive index; Filter for a display device comprising a. The method of claim 17, The external light shielding pattern is a stripe pattern having a wedge-shaped, rectangular, trapezoidal or U-shaped cross-sectional shape, and comprises a carbon black filter for a display device.

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