KR20100013046A - Method of manufacturing an optical filter as plasma display panel using roll to roll gravure offset printing process - Google Patents

Abstract

PURPOSE: A manufacturing method of an optical filter for a plasma display panel using a roll to roll gravure offset printing method is provided to maximize the contrast ratio, and to reduce loss of image light by irradiating ultraviolet rays on light sensitive transparent resin. CONSTITUTION: An electromagnetic wave shielding pattern is printed on a conductive paste component with a roll to roll gravure offset printing method. An infrared ray hardening resin is coated on the electromagnetic wave shielding pattern(20). The transparent resin in which light absorbing particles are mixed is filled in a waveguide(40). A color compensating layer(60) is formed on an external light absorbing unit(50) according to a laminating process.

Description

Method of manufacturing an optical filter as plasma display panel using Roll to Roll gravure offset printing process}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multifunctional optical filter for a plasma display panel. More particularly, the present invention relates to a light waveguide gap formed by simply forming a pattern by a roll to roll gravure offset printing method. The present invention relates to a method for manufacturing an optical filter for blocking external light by using a method of filling a light absorbing material by a roll laminating method in a simplified process.

The present invention relates to a multifunctional optical filter for a plasma display panel, which enables electromagnetic shielding and contrast ratio improvement at the same time, and which is integrated with a near infrared ray blocking, selective light absorbing layer, and an antireflection layer, and more particularly, a gravure offset printing. The present invention relates to a PDP optical filter which forms an electromagnetic shielding layer directly on a transparent substrate and fills an absorbing material in a gap between the optical waveguides formed along the pattern shape by a roll laminating method.

Plasma display panels are easier to be enlarged than other image display devices, and are thin light-emitting display devices that have the most suitable characteristics as high quality digital televisions in the future. However, the plasma display panel has a high emission amount of electromagnetic waves and near-infrared rays, high surface reflection in the partition walls and phosphors, and low contrast ratio and color purity of the cathode ray tube due to the orange light emitted from the encapsulated gas helium. Therefore, the display panel generally not only prevents harmful effects of human body and electromagnetic equipment by electromagnetic waves and near-infrared rays, but also reduces surface reflection, improves contrast, and improves electromagnetic shielding, near-infrared blocking, contrast enhancement, and surface to improve color purity. An optical filter having antireflection and color purity improvement functions is employed.

The conventional optical filter for PDP uses a metal etched mesh film, a metal fiber, or a metal coated organic fiber, which is formed by attaching a copper foil onto a polyester base film and patterning it to block such harmful electromagnetic waves. It can be broadly classified into a fiber mash type processed and patterned, or a conductive film type in which a metal (Ag) layer and a dielectric layer are alternately coated with a multilayer thin film by a dry coating method such as sputtering.

However, these electromagnetic shielding layer has a problem in that the manufacturing process is complicated and the amount of raw materials lost in the manufacturing process is high, and a separate film base material and an adhesive layer for attaching the film when the filter is manufactured by using a separate film substrate for forming the electromagnetic shielding layer are separately. In particular, since the existing electromagnetic wave shielding layer formed by mesh type has high haze, it is difficult to obtain clear image quality. Therefore, in order to use it as a filter, a process of transparentizing using a separate transparent resin layer or adhesive layer is required. Have

In order to solve this problem, Patent No. 0791205, "Optical filter for display panel and its manufacturing method", which forms an electromagnetic shielding layer by directly forming a conductive mesh pattern using a gravure offset printing method on a glass support. It is characterized by.

In addition, the partition walls and the phosphors constituting the unit cell of the plasma display panel improve luminous efficiency, and the partition walls use low-resistance white materials and use red, green, and blue phosphors to realize color. For this reason, the panel has a structural disadvantage that the contrast and color purity are degraded due to surface reflection by external light. In order to solve this problem, efforts have been made to improve the contrast in each field such as applying a black coating to the partition wall or employing a black optical filter having an appropriate transmittance. However, the blackening process on the bulkhead does not have a great effect, so it is necessary to supplement it in the filter. In the optical filter field, the light transmittance filter has a problem that the overall light intensity of the panel is lowered as well as the image light emitted from the panel. .

Designed to solve such a problem is a registered optical patent No. 0655087 "Optical light blocking device applied to the display", and designed an optical waveguide by an exposure process on a transparent substrate so that the image light of the panel can be transmitted without filtration, An external light blocking structure is formed by filling transparent resin containing light absorbing material in the gap of the optical waveguide.

It is an object of the present invention to directly print an electromagnetic shielding pattern on a substrate using a roll-to-roll gravure offset printing method, to cure by ultraviolet exposure method, and to apply UV light after applying a photoreactive transparent resin onto the printed substrate. By irradiating, it is providing the optical filter manufacturing method which does not require an expensive mask.

In addition, in order to create a structure that blocks external light, the light absorbing material is filled between the waveguides and a laminating method is used to deposit a film with a pressure sensitive adhesive having near infrared ray blocking and color correction on the filled light absorbing material. The coating is intended to provide an optical filter manufacturing method that can increase the absorption of external light, reduce the loss of image light that is internal light, maximize the contrast ratio, simplify the process, and obtain an increased production speed.

In the optical filter for PDP comprising an antireflection layer, a transparent substrate, a selective light absorbing layer, a contrast enhancement layer, an electromagnetic wave shielding layer and a near infrared ray shielding layer according to the present invention for achieving the above object, (a) using a conductive paste composition Printing an electromagnetic wave blocking pattern on a substrate by a gravure offset printing method; (b) coating a UV curable resin on the printed electromagnetic shielding pattern; (c) irradiating ultraviolet rays under the electromagnetic wave blocking pattern to expose them; (d) immersing and developing the UV curable resin laminated on the substrate after the exposure is finished; (e) forming a near infrared ray blocking and color correction layer on the external light absorbing portion by using a laminating process while simultaneously filling the transparent resin mixed with the light absorbing particles between the waveguides, wherein the near infrared ray blocking and color correction layer is formed on the PSA. A near-infrared blocking and color correction material is incorporated, and the PSA substrate is formed of an anti-reflective coating film, a transparent resin filling and near-infrared blocking and color correction layer forming step; (f) curing the filled transparent resin by exposing scattered light over the waveguide to completely cure the waveguide and the external light absorbing portion; (g) anti-glare hard coating (Anti-Glare-Hard-Coating) on the substrate; characterized by the configuration features.

As described above, the optical filter for PDP according to the present invention is formed by directly printing an electromagnetic shielding pattern on a transparent substrate such as a transparent film or glass, thereby eliminating the need to form an electromagnetic shielding pattern using an expensive photomask. Since the polyester film and the adhesive layer are not required, the structure of the filter is simplified, the loss of raw materials is reduced, and the production cost can be reduced.

In addition, since the external light blocking structure can be easily obtained by irradiating UV light through a pre-formed electromagnetic wave blocking pattern without using a mask, the exposure process can be simplified, the production time can be shortened and the mass production yield can be increased, and the transmittance and transparency It can be raised to improve the display quality.

In addition, the transparent resin containing light absorbing material in the gap between the waveguides is filled with a roll laminating method, and a pressure sensitive adhesive containing near infrared ray blocking and color correction materials is integrated with the antireflective coating film to simplify the process. Therefore, production time reduction effect and mass production yield improvement can be expected.

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

According to the present invention, the process is simplified by directly printing a conductive electromagnetic shielding pattern using a gravure offset printing method on a transparent substrate, which is a transparent film or glass, and by applying a photoreactive transparent resin on a substrate on which the electromagnetic shielding pattern is printed, UV light After the irradiation, the light absorbing material is filled by the upper and lower rolls in a lamination method, and at the same time, the near-infrared blocking layer is formed, which can significantly increase productivity and maximize uniformity and production yield.

The functional layers included in the optical filter for display of the present invention may be a conventional functional layer known in the art, and may have a conventional function, for example, antireflection function, selective light absorption function, electromagnetic wave blocking function, contrast enhancement Function, and near-infrared cut off function.

1 is a cross-sectional view showing a laminated structure of an optical filter of the present invention attached to a PDP panel.

As shown in FIG. 1, the optical filter 100 for display attached to the PDP panel 200 includes an antireflection layer 70, a substrate 10, an external light absorbing unit 50, a near infrared ray blocking layer, and a color correction layer 60. ) And an antireflection layer 80.

At the outermost side of the optical filter 100, an anti-reflection layer 80 for suppressing reflection of external light is disposed, and a contrast including a near-infrared blocking and color correction layer 60 including a near-infrared blocking material and a light selective absorbing material is provided. The external light absorbing portion 50 to be improved may be laminated on the front or rear surface of the transparent substrate 10 having the electromagnetic wave shielding layer directly formed thereon to obtain an optical filter for display.

The near-infrared blocking material may be a mixed pigment of nickel complex and diammonium, a dye or an organic dye of a compound containing copper or zinc ions, and the photo-selective absorbing material may be octaphenyltetraazaporphyrin or tetraaza. Derivative pigments in which a metal element is present as a central group in the porphyrin ring and in which any substance in the group consisting of ammonia, water and halogen form a coordinating bond with the metal element may be used. The pigment may be mixed with a UV-curable transparent resin to prepare a solution, and filled between the waveguides to prepare an external light absorbing part 50 to improve contrast.

The anti-reflection layer 80 may be formed by performing a hard coating made of an acrylic resin on the base film and then forming a low refractive index single layer or alternately laminating a high refractive index transparent film and a low refractive index transparent film. Examples thereof include vacuum deposition of the material and roll coating or die coating of the solution containing the material by a wet method.

The anti-reflection layer 80, the near infrared ray blocking and color correction layer 60, and the external light absorbing portion 50 may be formed on a separate substrate 10, and are formed by incorporating the near infrared ray blocking and selective absorbing pigment into the adhesive. You may.

2 to 7 are views showing the shape of the optical filter according to the step of configuring the optical filter 100 for PDP according to the first embodiment of the present invention.

An optical filter according to a first embodiment of the present invention,

(a) printing the electromagnetic wave shielding pattern on the substrate by using a conductive paste composition and using a gravure offset printing method;

(b) coating a UV curable resin on the printed electromagnetic shielding pattern;

(c) irradiating ultraviolet rays under the electromagnetic wave blocking pattern to expose them;

(d) immersing and developing the UV curable resin laminated on the substrate after the exposure is finished;

(e) forming a near infrared ray blocking and color correction layer on the external light absorbing portion by using a laminating process while simultaneously filling the transparent resin mixed with light absorbing particles between the waveguides, wherein the near infrared ray blocking and color correction layer is formed on the PSA. A near-infrared blocking and color correction material is incorporated, and the PSA substrate is formed of an anti-reflective coating film, a transparent resin filling and near-infrared blocking and color correction layer forming step;

(f) curing the filled transparent resin by exposing scattered light over the waveguide to completely cure the waveguide and the external light absorbing portion; And

(g) anti-glare hard coating (Anti-Glare-Hard-Coating) on the substrate; characterized by the configuration features.

Referring to the optical filter manufacturing method as described above in detail, it has the following features.

In order to manufacture the optical filter for PDP according to the present invention, the electromagnetic shielding pattern 20 is first printed on the substrate 10 of FIG. 2 by a gravure offset method (see FIG. 3). In this case, the substrate may be a transparent film, sheet, glass, or the like.

The electromagnetic wave shielding pattern according to the present invention has a contrast enhancement structure manufactured in consideration of transmittance, horizontal and vertical viewing angles, and moiré with a panel pattern using a simulation tool. In addition, it is designed in a pattern that maximizes the electromagnetic shielding efficiency in addition to the above optical characteristics by using the HFSS (High Frequency Structure Simulator). Such a pattern is preferably inclined at an angle of 3 to 50 degrees to the horizontal pattern of the panel, and the vertical line width of the electromagnetic shielding pattern is produced by dividing the stages. Preferably, the vertical pattern is repeated by dividing the stage into two to three stages. In addition, each cell of the electromagnetic shielding pattern has a horizontal size of 100 to 2000 μm, a line width of 5 to 40 μm, a vertical size of 50 to 300 μm, and a line width of 5 to 40 μm. The material constituting the electromagnetic wave shielding pattern is a conductive paste composition of UV and EB curing type, and includes nano-sized metal powder, contains additives and solvents to obtain dispersion safety, and controls curing rate and degree of curing. It includes a binder and a curing agent, and includes a material for improving the printability of the pattern to improve the straightness, adhesion, line width spreadability, film stability of the pattern.

Since the conventional electromagnetic wave shielding layer formed of a mesh type has high haze, it is difficult to realize a clear image quality, but in order to use it as a filter, a process of making it transparent using a separate transparent resin layer or an adhesive layer is necessary. In the case of the optical filter for display manufactured by using the electromagnetic wave shielding layer printed directly on the glass by the gravure offset printing method using the printing paste composition as described above, the haze value is about 3% and excellent in transparency.

A UV curable monomer or oligomer (hereinafter referred to as UV curable resin), which becomes the material of the waveguide, is coated on the printed electromagnetic wave shielding pattern (see Fig. 4). At this time, the photoinitiator is added to the UV curable resin 30. At this time, the UV curable resin, which is a coating agent, has a high transparency and a difference between the PET and the refractive index is 0.01 or less, and when cured, the shrinkage of the resin itself is within 3 to 5%, and the adhesion to the substrate is high and the curing is performed. Subsequent hardness of 2H or more, less deformation due to heat or moisture, yellowing by heat or light, and includes two or more kinds of initiators having different reaction wavelengths, and includes a material that improves leveling during coating. As the photoinitiator added to the coating agent, benzyl dimethyl ketal, diethyl oxy acetophenone, hydroxy methpropiophenone or the like or a mixture thereof may be used.

When ultraviolet rays are exposed from the bottom of the electromagnetic wave shielding pattern 20, the coated UV curable resin is divided into a cured part and an uncured part. Since the electromagnetic wave shielding pattern was directly printed on the substrate by the gravure offset method, it can be cured without using a separate mask.

After exposure, when the UV curable resin 30 laminated on the transparent substrate is immersed in a developing solution, the cured portion becomes the waveguide 40, and the remaining uncured portion is removed (see FIG. 5). In this case, isopropane alcohol (IPA), methanol, water, toluene, acetone, propylene glycol mono methyl ether acetate (PGMEA), and the like may be used as the developer.

 After the development, the waveguide formed after drying is removed from the developer and dried.The waveguide, which is formed after drying, is semi-cured, and the height and sidewall slope of the waveguide can maximize the external light blocking effect. It may vary depending on the pattern.

After the drying process, the transparent waveguide is filled with a transparent resin mixed with light absorbing particles between the waveguides in a semi-cured state. It may be possible (see Fig. 6). According to the present invention, a black fill process is used to fill the transparent resin between the waveguides. Specifically, the light absorbing material is filled into the light absorbing portion between the waveguides by the upper and lower rolls while supplying the light absorbing material and at the same time preventing reflection. (Anti-Reflection coating) Laminates the coated substrate and the PSA-integrated film containing the near infrared ray blocking and color correction pigments. It fills the absorbing material between the waveguides and fills the light absorbing material without using the squeeze method, but fills the light absorbing material using the lamination method. Since the coating is made in one process, the process is simple and has an advantage of increasing production speed.

After the transparent resin is completely filled in the light absorbing portion between the waveguides, the transparent resin is cured by being exposed to scattered light above the transparent resin between the waveguides, thereby forming an external light absorbing portion 50 between the waveguides.

The anti-glare hard coating layer 70 is formed on the substrate 10 to be opposite to the near-infrared cutoff and color correction layer 60 (see FIG. 7).

PDP optical filter according to a second embodiment of the present invention,

(a) printing the electromagnetic wave shielding pattern 20 on the substrate 10 by using a conductive paste composition and using a gravure offset printing method;

(b) coating the UV curable resin on the opposite side of the substrate 10 on which the printed electromagnetic shielding pattern 20 is printed;

(c) exposing the ultraviolet light over the electromagnetic wave shielding pattern 20 to expose the light;

(d) immersing and developing the UV curable resin 30 laminated on the substrate after the exposure is finished;

(e) forming a near infrared ray blocking and color correction layer 60 on the external light absorbing portion by using a laminating process at the same time as filling the transparent resin mixed with light absorbing particles between the waveguides, the near infrared ray blocking and color correction layer The near-infrared blocking and color correction materials are incorporated into the silver PSA, and the PSA substrate is formed by using an anti-reflective coating film, transparent resin filling and near-infrared blocking and color correction layer forming steps;

(f) exposing scattered light on the waveguide 40 to cure the filled transparent resin to form an external light absorbing portion 50; And

(g) forming an anti-glare hard coating layer 70 on the electromagnetic wave shielding pattern 20.

In the second embodiment, unlike the first embodiment, the UV curable resin 30, which is a material of the waveguide, is formed on the substrate opposite to the electromagnetic wave shielding pattern (see FIGS. 2 and 3) printed by a gravure offset printing process. Coated (see Figure 8).

Next, after irradiating ultraviolet rays or applying heat from the electromagnetic wave shielding pattern 20, the UV curable resin 30 laminated on a transparent substrate is immersed in a developing solution to remove the uncured portion (see FIG. 9). .

After the development is completed, the developer is taken out of the developing solution and subjected to a drying process, and then the transparent resin is filled between the semi-cured waveguides 40. At the same time, the film is laminated with an anti-reflection coating coated substrate and a PSA incorporating a near infrared ray blocking and color correction pigment.

After the transparent resin is completely filled in the light absorbing portion between the waveguides, the scattered light is exposed on the waveguide 40 to cure the filled transparent resin to form the external light absorbing portion 50 (see FIG. 10).

Next, the anti-glare hard coating is performed on the electromagnetic wave shielding pattern to prevent glare and to prevent glare (see FIG. 11). Other contents are the same as those of the first embodiment, and further description thereof will be omitted.

12 to 14 are views showing various patterns implemented in the optical filter for display according to the present invention, and as shown, may have a polygonal network structure.

The optical filter for PDP thus formed may be fixedly used through a separate jig to a TV set.

The above description is merely illustrative of the technical details of the present invention, and those skilled in the art to which the present invention pertains may various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

1 is a cross-sectional view showing the configuration of an optical filter.

2 to 7 are cross-sectional views showing forms of optical filter manufacturing steps according to the first preferred embodiment of the optical filter for display according to the present invention.

8 to 11 are cross-sectional views showing forms of optical filter manufacturing steps according to a second preferred embodiment of the optical filter for display according to the present invention.

12 to 14 are views showing various patterns implemented in the optical filter for display according to the present invention.

** Explanation of symbols on the main parts of the drawing **

10: substrate 20: electromagnetic wave blocking pattern

30: UV curable resin 40: Waveguide

50: external light absorbing unit 60: near infrared ray blocking and color correction layer

70 anti-glare hard coating layer (reflective layer)

80: antireflection layer

100: optical filter 200: PDP panel

Claims (9)

In the optical filter for display comprising an antireflection layer, a transparent substrate, an optional light absorbing layer, a contrast enhancement layer, an electromagnetic wave shielding layer and a near infrared ray shielding layer, (a) printing the electromagnetic wave shielding pattern on the substrate by using a conductive paste composition and using a gravure offset printing method; (b) coating a UV curable resin on the printed electromagnetic shielding pattern; (c) irradiating ultraviolet rays under the electromagnetic wave blocking pattern to expose them; (d) immersing and developing the UV curable resin laminated on the substrate after the exposure is finished; (e) forming a near infrared ray blocking and color correction layer on the external light absorbing portion by using a laminating process while simultaneously filling the transparent resin mixed with the light absorbing particles between the waveguides, wherein the near infrared ray blocking and color correction layer is formed on the PSA. A near-infrared blocking and color correction material is incorporated, and the PSA substrate is formed of an anti-reflective coating film, a transparent resin filling and near-infrared blocking and color correction layer forming step; (f) curing the filled transparent resin by exposing scattered light over the waveguide to completely cure the waveguide and the external light absorbing portion; And (g) anti-glare hard coating (Anti-Glare-Hard-Coating) on the substrate; characterized in that Method for manufacturing optical filter for display. In the optical filter for display comprising an antireflection layer, a transparent substrate, an optional light absorbing layer, an electromagnetic wave shielding layer and a near infrared ray shielding layer, (a) printing the electromagnetic wave shielding pattern on the substrate by using a conductive paste composition and using a gravure offset printing method; (b) coating a UV curable resin on the opposite side of the substrate on which the printed electromagnetic shielding pattern is printed; (c) irradiating ultraviolet rays over the electromagnetic wave shielding pattern to expose the light; (d) immersing and developing the UV curable resin laminated on the substrate after the exposure is finished; (e) forming a near infrared ray blocking and color correction layer on the external light absorbing portion by using a laminating process while simultaneously filling the transparent resin mixed with the light absorbing particles between the waveguides, wherein the near infrared ray blocking and color correction layer is formed on the PSA. A near-infrared blocking and color correction material is incorporated, and the PSA substrate is formed of an anti-reflective coating film, a transparent resin filling and near-infrared blocking and color correction layer forming step; (f) exposing scattered light on the waveguide to cure the filled transparent resin to form an external light absorbing portion; (g) forming an anti-glare hard coating layer on the electromagnetic wave shielding pattern; Method for manufacturing optical filter for display. The method according to claim 1 or 2, The electromagnetic wave blocking pattern is a structure that can eliminate the moiré phenomenon with the panel pattern Method for manufacturing optical filter for display. The method according to claim 1 or 2, The electromagnetic wave blocking pattern is a structure that can improve the contrast when the waveguide is formed Method for manufacturing optical filter for display. The method according to claim 1 or 2, The electromagnetic shielding pattern is a structure that maximizes the electromagnetic shielding efficiency using HFSS Method for manufacturing optical filter for display. The method according to claim 1 or 2, The electromagnetic shielding pattern is manufactured by tilting the panel horizontal pattern 3 to 50 degrees, and the vertical pattern is configured to be shifted from each other in 2 to 5 steps. Method for manufacturing optical filter for display. The method according to claim 1 or 2, The horizontal size of each cell of the electromagnetic wave blocking pattern is 100 ~ 2000㎛, line width 5 ~ 40㎛, vertical size is 50 ~ 300㎛, characterized in that the line width 5 ~ 40㎛ Method for manufacturing optical filter for display. The method according to claim 1 or 2, The near-infrared blocking and color correction material is incorporated into the PSA is characterized in that the integrally manufactured with the anti-reflective coating film Method for manufacturing optical filter for display. The method according to claim 1 or 2, The electromagnetic wave blocking pattern has a polygonal network structure Method for manufacturing optical filter for display.

Images