KR20100088759A - External light blodking film and optical filter having the same - Google Patents

Abstract

PURPOSE: An external light shielding and an optical filter having the same are provided to improve the external light shielding performance and the transmittivity. CONSTITUTION: A reflection preventing layer(120) restrains the reflection of the external light, and improves the visibility. An electromagnetic wave shield layer(130) uses an electromagnetic wave shielding layer(130a) of the conductive mesh type or an electromagnetic wave shield layer of conductive film type. An external light shielding layer(140) comprises a base(143) of transparent resin and an external light shield pattern(145).

Description

External light shielding film and optical filter having same {EXTERNAL LIGHT BLODKING FILM AND OPTICAL FILTER HAVING THE SAME}

The present invention relates to a display device, and more particularly, to an external light shielding film and an optical filter used in the display device.

Display devices include televisions, PC monitors, portable display devices, and the like. Display devices have tended to have larger screen sizes and thinner screens.

Accordingly, Cathode Ray Tube (CRT) devices, which are representative of display devices, include Liquid Crystal Display (LCD), Plasma Display Panel (PDP) devices, and Field Emission Display devices. : Flat panel display (FPD), such as FED) and organic light emitting display (OLED).

PDP devices have been spotlighted for their excellent display ability such as brightness, contrast, afterimage, viewing angle, and the like.

In the PDP apparatus, discharge occurs in the gas between the electrodes by a direct current or an alternating voltage applied to the electrodes, and the image is displayed by emitting light by excitation of the phosphor by the radiation of ultraviolet rays.

However, the PDP device has a problem in that a large amount of electromagnetic waves and near infrared rays are emitted. Electromagnetic waves and near-infrared rays have a harmful effect on the human body and may cause malfunctions of precision devices such as cordless phones and remote controls. In addition, due to the orange light emitted from the He or Xe gas there is a problem that the color purity is not as good as compared to the CRT device.

Therefore, the PDP apparatus employs a PDP filter to solve this problem. PD filter is installed in front of the display module.

However, the conventional PDP filter has the following problems.

The filter includes an external light shielding film to improve the visibility of the PD device. However, the transmittance of the currently used external light shielding film is less than about 70%, which is a limiting factor in improving the transmittance of the filter employing the same. In addition, due to the external light shielding film, a significant level of contrast contrast (BRCR) has been improved, but is still required to improve the external light shielding performance compared to LCD TVs that are still competing in the thin-film TV market.

The present invention has been made in order to solve the above-described needs, the object of the present invention is to provide an excellent external light shielding film and filter having an improved external light shielding performance and transmittance than conventional external light shielding film by optimizing the shape and dimensions of the wedge shaped external light shielding part. have.

In order to achieve the above object, the present invention is an external light shielding film for an optical filter disposed in front of the display device, the substrate and an external light shielding pattern formed on the substrate, the light absorbing material is filled to absorb external light The outer light shielding pattern is formed by arranging a plurality of wedge shaped outer light shielding parts, and 0.24 ≤ (width of the wedge shaped light shielding part) / (pitch of the wedge shaped light shielding part) ≤ 0.28 and 5 ≤ (wedge shaped outer light) It provides an external light shielding film characterized in that the height of the shield) / (the width of the wedge-shaped external light shielding portion) ≤ 8.

More preferably, 0.24 ≤ (width of the wedge shaped light shield) / (pitch of the wedge shaped light shield) ≤ 0.26 and 6 ≤ (height of the wedge shaped light shield) / (width of the wedge shaped light shield) ≤ 8, and even more preferably, 0.24 ≤ (width of the wedge shaped light shield) / (pitch of the wedge shaped light shield) ≤ 0.26 and 6 ≤ (height of the wedge shaped light shield) / (wedge shaped light) Width of the shielding part) ≤ 7.

Preferably, the wedge shaped exterior light shielding portion is arranged such that its bottom surface faces the display module of the display device.

The external light shielding film may include a support material, and the substrate may be laminated on the support material.

In addition, the present invention provides an optical filter comprising the external light shielding film.

According to the above configuration, the present invention has a higher transmittance than the conventional external light shielding film to prevent the loss of light emitted from the display module, there is an effect that can further increase the transmittance control range in the filter development.

In addition, it is possible to provide a higher contrast ratio under bright room conditions by improving external light absorption performance.

Through this, the present invention can provide an external light shielding film capable of displaying a clear image and an optical filter for a display device applying the same.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1 is an exploded perspective view schematically illustrating a display device according to a first exemplary embodiment of the present invention.

Referring to FIG. 1, a PDP device 300, which is a type of display device according to an embodiment of the present invention, may include a case 310, a cover 320, a driving circuit board 330, and a display module 340. ) And a filter 100.

The cover 320 covers the case at the front of the case. The driving circuit 330 is accommodated in the case 310. The display module 340 includes a light emitting cell in which gas discharge occurs and displays an image.

The filter 100 is mounted in front of the display module 340. The electromagnetic shielding layer 130 of the filter 100 to be described later may be grounded with the case 310 through the cover 320. Through this, electromagnetic waves generated from the display module 340 are shielded from being transmitted to the viewer.

The optical filter for display device of the present invention is a transparent substrate 110, anti-reflection layer 120, electromagnetic shielding layer 130, external light shielding layer 140, color correction layer, near infrared shielding layer 180, anti-glare layer 190 And various functional optical layers may be included, if necessary.

2 is a cross-sectional view schematically showing the structure of a filter according to a second embodiment of the present invention.

The filter of Figure 2 is sequentially from the front of the anti-reflection layer 120, the near infrared shielding layer 180, the transparent substrate 110, the electromagnetic shielding layer 130, the external light shielding layer 140 and the anti-glare film (Anti-Glare film) It includes.

However, FIG. 2 is merely illustrative of embodiments of the present invention and various modifications are possible.

For example, the type of layers constituting the filter of the present invention may be variously selected according to the function of the filter to be obtained. For example, the layers constituting the filter of FIG. 2 may be deleted or other layers added at any time as needed.

In addition, the filter of the present invention may have various modified embodiments even in the stacking order thereof. For example, the stacking order of the layers constituting the filter of FIG. 2 may be modified at any time as needed.

It is also possible to have a hybrid layer that performs a combination of functions performed by two or more layers. For example, the near-infrared shielding layer 180 may be formed as a separate layer as shown in FIG. 2, or may be configured as a hybrid layer including a near-infrared material in the color correction layer.

Separate each floor.

Transparent substrate (110)

The material of the transparent substrate 110 may include an inorganic compound molding and an organic polymer molding. Examples of the inorganic compound molded article include semi-tempered glass, quartz, and the like.

Organic compound moldings include polyethylene terephthalate (PET), acrylic (poly), polycarbonate (PC), urethane acrylate (polyurethane acrylate), polyester (polyester), epoxy acrylate (Epoxy acrylate), Brominated acrylate (PolyVinyl Chloride, PVC), etc. are mentioned.

The transparent substrate 110 may be transparent in the visible light region, and preferably, the transmittance of the visible light is 80% or more.

Anti-reflection layer 120

The antireflection layer 120 suppresses reflection of external light to improve visibility.

The antireflection layer may be formed of a thin film such as i) fluorine-based transparent polymer resin, ii) magnesium fluoride, iii) silicon-based resin, iv) silicon oxide, or the like having a refractive index of 1.5 or less, preferably 1.4 or less, in the visible region. A single layer formed by the optical film thickness of / 4 wavelength can be used.

In addition, it is reflected that two or more layers of thin films of inorganic compounds such as metal oxides, fluorides, silicides, borides, carbides, nitrides and sulfides having different refractive indices or organic compounds such as silicone resins, acrylic resins and fluorine resins are laminated. It can be used as a prevention layer. For example, the antireflection layer may have a structure in which a low refractive index oxide film such as SiO ₂ and a high refractive index oxide film such as TiO ₂ or Nb ₂ O ₅ are alternately stacked.

Electromagnetic shielding layer (130)

The electromagnetic shielding layer 130 is typically an electromagnetic shielding layer 130a of a conductive mesh type or an electromagnetic shielding layer of a conductive film type.

In FIG. 2, the electromagnetic shielding layer 130a of the conductive mesh type is shown. The electromagnetic shielding layer 130a of the conductive mesh type typically has a structure in which a conductive mesh pattern is formed on a backing.

As the conductive mesh pattern, i) metal mesh, ii) metal coating on synthetic resin mesh, or iii) metal coating on metal fiber mesh can be used.

As the material of the metal constituting the metal mesh pattern, for example, copper, chromium, nickel, silver, molybdenum, tungsten, aluminum, and the like can be used as long as the metal has excellent electrical conductivity and processability.

Compared with the electromagnetic shielding layer of the conductive film type described below, the electromagnetic shielding layer 130a of the conductive mesh type does not have a near infrared shielding performance, and thus has a separate near infrared shielding layer and / or an electromagnetic shielding layer of the conductive mesh type 130a. The near-infrared absorbing pigment | dye can be contained in the support material of this.

The electromagnetic shielding layer of the conductive film type may be composed of a multilayer transparent foil by alternately stacking a metal thin film and a metal oxide thin film. As the metal thin film, gold, silver, copper, platinum, palladium, or the like can be used. As the metal oxide thin film, indium tin oxide (ITO), ditin tin oxide, zinc oxide (ZnO), zinc oxide doped with aluminum (AZO), or the like may be used.

The electromagnetic shielding layer of the conductive film type has an effect of shielding near infrared rays. Instead of forming a near-infrared shielding layer, two functions of shielding electromagnetic waves and near-infrared rays can be performed only by the electromagnetic shielding layer of the conductive film type. In this case, of course, the near-infrared shielding layer may be formed separately.

External light shielding layer 140

The external light shielding layer 140 includes a transparent resin substrate 143 and an external light shielding pattern 145 formed on one surface of the substrate.

Although not shown, the external light shielding layer may include a backing. In this case, the substrate is formed on the support member. The support material is preferably a transparent resin film. For example, polyethylene terephthalate (PolyEthylene Terephthalate) (PET), polycarbonate (PC), polyvinyl chloride (PVC), or the like may be used as the material of the support material. As the support material, a film having an inherent function of the filter, for example, an antireflection layer 120, a color correction layer, or an electromagnetic shielding layer 130 may be used.

The substrate 143 is made of a transparent material that transmits visible light, and includes polyethylene terephthalate (PET), acrylic, polycarbonate (PC), urethane acrylate (polyurethane acrylate), and polyester (polyester). ), Epoxy acrylate (Epoxy Acrylate), brominated acrylate (Brominate Acrylate), polyvinyl chloride (PolyVinyl Chloride, PVC), and the like.

In addition, the substrate may be made of a thermoplastic resin, a thermosetting resin, an ultraviolet curable resin, and the like.

An intaglio pattern to be filled with the light absorbing material, etc. is formed on the substrate by a roll forming method, a hot press method, a casting method, an injection molding method, or the like.

The external light shielding pattern may be formed using an ultraviolet curable resin mixed with a light absorbing material. As the light absorbing material, a black inorganic material and / or an organic material that can absorb light is used, and typically carbon black This is used. In addition, the external light shielding pattern may include a conductive material such as a metal. When the external light shielding pattern is formed by adding the metal powder, the external light shielding pattern may perform an electromagnetic shielding function because the electrical resistance may be adjusted according to the concentration of the metal powder. If black surfaces or black metal are used, external light shielding and electromagnetic shielding can be effectively implemented.

The external light shield pattern 145 includes a plurality of external light shields. When viewed from the front, the external light shield is typically formed long in the horizontal direction. Accordingly, the external light shielding pattern 145 typically has a stripe pattern when viewed from the front, but may also have various modified embodiments such as a wavy pattern, a mesh pattern, and the like.

The external light shielding portion typically has a wedge shape, that is, a trapezoidal shape or a triangular shape when viewed from the side. This includes isosceles triangles and isosceles trapezoids, as well as various other wedge-shaped shapes. For example, the upper surface of the external light shielding portion may be formed as an inclined surface, and the lower surface may be formed as a horizontal surface.

In order to improve the transmittance and the external light absorption performance of the external light shielding film, the following two conditions must be satisfied simultaneously.

0.24 ≤ (width of the wedge shaped light shield) / (pitch of the wedge shaped light shield) ≤ 0.28 and 5 ≤ (height of the wedge shaped light shield) / (width of the wedge shaped light shield) ≤ 8.

Here, the pitch of the external light shielding means the distance between the corresponding points of the two external light shielding.

Table 1 shows the results of manufacturing the external light shielding film by varying the two factors and measuring the transmittance and the external light reflectance. (Front roughness of PDPD device: 150 Lux, after attaching filter to the front of SDI W2 PDP module, external light reflectance was measured)

b / p h / b b Transmittance External light reflectance Test Example 1 25 6.5 19.0 75% 0.8 Test Example 2 27 6.1 20.0 73% 0.9 Comparative Example 1 30 4.6 22.3 68% 1.2

Test Example 1

A roll mold is produced in the shape of a wedge having the dimensions specified in Test Example 1. Using a comma coater on one side of the optical PET as a backing material, a urethane-acrylic UV resin with a solid-state refractive index of 1.53 was coated with a thickness of about 150 μm, and then a pattern was formed by using a wedge-shaped mold manufactured and UV cured. To produce a substrate. Black ink in which carbon black having an average particle diameter of 50 nm is dispersed at a 3% weight ratio is mixed with a UV cured resin to produce a black resin having a refractive index of 1.53. The resin was poured onto the substrate on which the intaglio pattern was formed, and black resin was filled into the pattern by wiping to complete the external light shielding film.

Test Example 2

The roll mold is produced in the shape of the wedge of the dimension specified in the test example 2. The surface of the optical PET is coated with a comma coater on a urethane acrylic UV resin having a solid-state refractive index of 1.53 to a thickness of about 150 μm, and then a pattern is formed using a mold and UV cured. Black ink in which carbon black having an average particle diameter of 50 nm is dispersed at a 3% weight ratio is mixed with a UV cured resin to produce a black resin having a refractive index of 1.53. This resin was poured onto the substrate on which the pattern was formed, and black resin was formed in the pattern using the wiping method.

Comparative Example 1

The roll mold is produced in the shape of the wedge of the dimension specified in the comparative example 1. On one side of the optical PET, a urethane arc UV resin having a solid-state refractive index of 1.53 is coated with a microvia to a thickness of about 150 μm, and then a pattern is formed using a wedge-shaped mold and UV cured. Black ink in which carbon black having an average particle diameter of 50 nm is dispersed at a 3% weight ratio is mixed with a UV cured resin to produce a black resin having a refractive index of 1.53. This resin was poured onto the substrate on which the pattern was formed, and black resin was formed in the pattern using the wiping method.

Comparative Example 1 is the structure of the external light shielding film most widely used at present. As in Test Examples 1 and 2, it can be seen that as the trapezoidal height of the wedge is 5 times or more the width / pitch ratio of the width of the external light shielding portion, the transmittance is higher than that of Comparative Example 1. In addition, as the external light absorbency is better, the external light reflectance value is smaller, but the external light reflectance values of Test Examples 1 and 2 are lower than those of Comparative Example 1, and thus the external light shielding performance is further improved.

3 is a rear enlarged picture of the external light shielding film of Test Example 2, and FIG. 4 is a cross-sectional enlarged picture of the external light shielding film of Test Example 2. FIG.

In Fig. 3, an external light shielding film having a width, b of 20.83 μm, a pitch, p of 75.18 μm, and an interval between the external light shielding parts of 51.55 μm is shown.

In Fig. 4, the width (on the back) of the external light shielding part, b is 20.69 m, the width at the front of the external light shielding part is 11.11 m, the height of the external light shielding part, h is 126.36 m, and the height (thickness) of the substrate is 135 m. It shows an external light shielding film.

FIG. 5 is a graph showing BRCR and transmittance values obtained by testing while changing b / p while fixing h.

Fixing h at 102 μm and measuring the transmittance and bright room contrast ratio (BRCR) at different b / p results in Table 2 and FIG. 5.

b / p h External light reflectance Transmittance BRCR Viewing angle 30% 102 μm 1.21 68% 526.7 24.3 27% 102 μm 1.47 72% 447.2 25 25% 102 μm 1.8 75% 406.4 25.9 21% 102 μm 2.263 79% 341.0 27.8

As b / p increases, the BRCR increases but the transmittance value decreases drastically. Since b / p can find a tradeoff between transmittance and BRCR characteristics between 24% and 28%, it is possible to find conditions to minimize display brightness losses while effectively blocking external light in this range.

6 is a graph showing BRCR and viewing angle values obtained by testing while changing h / b while fixing b / p.

By fixing b / p at 27% and measuring the BRCR and viewing angle with increasing h, the results in Table 3 and FIG. 6 can be obtained.

b / p h External light reflectance Transmittance BRCR Viewing angle 27% 102 (BS length x 5.1) 1.47 72% 447.2 25 27% 120 (BS length x 6.0) 1.21 71% 535.7 22 27% 146 (BS length x 7.3) 0.81 70% 789 18

As can be seen in Table 3 and FIG. 6, as the height of h / b increases, the BRCR increases but the viewing angle decreases. Therefore, in order to increase the BRCR, h / b cannot be increased indefinitely, and h / b is preferably 6 to 7 considering the viewing angle.

To summarize the above test results, h is 6 ~ 7 and b / p is 24 ~ 28% range in order to maximize the external light shielding effect and improve the transmittance to prevent luminance loss.

Here, BRCR (Bright Room Contrast Ratio) is expressed as a white luminance / black luminance value, and the viewing angle is represented by averaging the upper and lower angle values at the time when the luminance becomes 1/2 of the front of the display device.

Table 4 below shows another test result.

b / p h / b Transmittance BRCR Viewing angle 21% 5 80 233.8 39.1 30% 5 68 569 23.5 21% 8 78 341 32.9 30% 8 66 672.9 20.9 25% 6 74 475.9 25.2

As a result of the test, drawing the optimal graph of the dimensions of the external light shielding part that can improve the transmittance of 3% or more and maintain the viewing angle characteristics while increasing the external light shielding effect compared to the existing external light shielding film, b / p is 24 ~ 26, h / b is 6 or more is applicable. However, the height of the wedge cannot be raised indefinitely by the mold processing technology, and when the height of the wedge is increased, the viewing angle characteristic deteriorates, so the height of the wedge is preferably about 6-8.

When summarizing the test results, b / p should preferably have a value of 0.24 to 0.28, more preferably 0.24 to 0.26, and h / b is preferably 5 to 8, more preferably 6 to 8 Even more preferably, it should have a value of 6-7.

As can be seen from the above test, since the values of b / p and h / b correlate to BRCR, transmittance and viewing angle, only one of the two conditions of the present invention is satisfied. Can not achieve the purpose.

For example, even if the value of b / p is within the above range, if the value of h / b is less than 5, the object of the present invention cannot be achieved. That is, in the present invention, the above two conditions need to be satisfied together, and only in this case, excellent BRCR, transmittance, and viewing angle characteristics can be obtained by synergistic interaction with each other.

The external light shielding pattern 145 typically has a wedge-shaped bottom surface facing the display module, but the present invention is not limited thereto. That is, the wedge bottom surface may face the viewer, and the wedge pattern may be formed on both the front and back surfaces of the substrate.

In addition, the external light shielding pattern 145 is typically formed in an intaglio with respect to the substrate 143, it may be formed in an embossed.

The external light shielding layer 140 absorbs external light to prevent external environment light from entering the display module. The wedge slope of the external light shielding layer 140 totally reflects the screen light emitted from the display module toward the viewer. Therefore, the visible light emitted from the display is effectively transmitted while the external light is effectively blocked, thereby contrasting the contrast in indoor lighting conditions or outdoor exterior lighting conditions (external light enters the filter obliquely from above) that is most similar to the actual viewing conditions of the display device. Increase the rain to provide clear images.

Color Correction Layer

The color correction layer changes or corrects the color balance by reducing or adjusting the amounts of red (R), green (G), and blue (B). The color correction layer may include a polymer resin in which a coloring pigment and a neon cut pigment are mixed.

The color correction layer uses various pigments to increase the color reproduction range of the display and to improve the sharpness of the screen. As such a dye, a dye or a pigment can be used.

In general, red visible light generated from plasma in the display module tends to appear changed to orange. Therefore, the orange cut (neon light) is absorbed using a neon cut dye to lower the transmittance of light in the wavelength band.

The neon-cut dye is not particularly limited because it only absorbs 10% to 90% of light having a wavelength of 550 to 610, but is not particularly limited. Cyanine-based, polymethine-based, squarylium salt-based, phthalocyanine-based, naphthalocyanine-based and quinone-based , Azaporphyrin-based, azo-based, azochelate-based, azurenium-based, pyryllium-based, croconium-based, indoaniline-chelated-based, indonaphthol-chelated-based, dithiol metal complexes, pyrromethene-based, azomethine-based, xanthene-based, Oxonol system, etc. can be used.

As the coloring pigment, cyanine, anthraquinone, naphthoquinone, phthalocyanine, naphthalocyanine, dimonium, nickel dithiol, azo, stryl, phthalocyanine, methine, porphyrin, azaporphyrin, And the like can be used.

However, the pigment | dye of this invention is not limited to the kind illustrated above. Since the type and concentration of the dye are determined by the absorption wavelength, absorption coefficient, and transmission characteristics required for the display, the dye is not limited to a specific kind or numerical value.

Near Infrared Shielding Layer (180)

Since PDP devices generate strong near infrared rays over a wide wavelength range, it is necessary to use a near infrared shielding layer capable of absorbing near infrared rays over a wide wavelength range.

The near infrared shielding layer 180 functions to shield near infrared rays in the 850 to 950 nm wavelength range that causes malfunction of electronic devices such as a wireless telephone or a remote controller. Near-infrared radiation emitted by the PDP device is shielded by the near-infrared shielding layer 180, so that even if a remote control device, an optical communication device, or the like is used in the vicinity of the PDP device, the operation is not disturbed.

The near infrared shielding layer may comprise a near infrared absorbing material. As the near-infrared absorbing material, a material that selectively absorbs wavelength light in the near infrared region is required.

The near-infrared absorbing material usable in the present invention is not particularly limited, i) mixed pigment of nickel complex and diammonium, ii) compound dye containing copper ions and zinc ions, iii) cyanine dye, iv) anthraqui Non-dye, v) squarylium-based compound, vi) azomethine-based compound, vii) ocisonol compound, viii) azo-based compound and ix) at least one selected from the group consisting of benzylidene-based compounds can be used.

Adhesive layer

Although not shown, a transparent pressure-sensitive adhesive or an adhesive may be used when pasting each layer of the present invention. Specific materials include i) acrylic adhesives, ii) silicone adhesives, iii) urethane adhesives, iv) polyvinylbutyral adhesives (PMB), v) ethylene-vinyl acetate adhesives (EVA), vi) polyvinylether adhesives, vii A) saturated amorphous polyester adhesive, viii) melamine resin adhesive, and the like.

However, depending on the layer, it can be formed by a direct coating method without mediating the adhesive layer. For example, the near-infrared shield layer 180 of FIG. 2 may be formed by being directly coated on the rear surface of the anti-reflection layer 120. In addition, the conductive film type electromagnetic shielding layer is typically formed by direct coating on the back surface of the transparent substrate.

The adhesive layer is typically transparent, but may have a color including a neon cut dye and / or a coloring pigment. In this case, the adhesive layer has a color correction function in place of the color correction layer or by assisting the color correction layer.

The PDP filter and the PDP device have been described so far for the convenience of description, but the present invention is not limited thereto. It can be applied to a large display device such as an FED device, ii) a small mobile display device such as PDA (Personal Digital Assistants), a small game machine display window, a mobile phone display window, and iii) a flexible display device. .

 1 is an exploded perspective view schematically illustrating a display device according to a first exemplary embodiment of the present invention.

2 is a cross-sectional view showing the structure of a filter according to a second embodiment of the present invention.

Figure 3 is a rear enlarged photograph of the external light shielding film of Test Example 2.

Figure 4 is an enlarged cross-sectional picture of the external light shielding film of Test Example 2.

FIG. 5 is a graph showing BRCR and transmittance values obtained by testing while changing b / p while fixing h.

6 is a graph showing BRCR and viewing angle values obtained by testing while changing h / b while fixing b / p.

Claims (6)

An external light shielding film for an optical filter disposed in front of a display device, Materials and It is formed on the substrate, the light absorbing material is filled with an external light shielding pattern for absorbing external light, The external light shielding pattern is made of a plurality of wedge-shaped external light shielding is arranged 0.24 ≤ (width of the wedge shaped light shield) / (pitch of the wedge shaped light shield) ≤ 0.28 and 5 ≤ (height of the wedge shaped external light shielding part) / (width of the wedge shaped external light shielding part) ≤ 8, characterized in that the external light shielding film. The method of claim 1, The external light shielding film, characterized in that the bottom surface is arranged so that the bottom surface facing the display module of the display device. The method of claim 1, The external light shielding film includes a support material, The substrate is an external light shielding film, characterized in that formed on the support material laminated. The method of claim 1, 0.24 ≤ (width of the wedge shaped light shield) / (pitch of the wedge shaped light shield) ≤ 0.26 and 6 ≤ (height of the wedge-shaped outer light shielding part) / (width of the wedge-shaped outer light shielding part) ≤ 8, characterized in that the external light shielding film. The method of claim 4, wherein 6 ≤ (height of the wedge-shaped outer light shielding portion) / (width of the wedge-shaped outer light shielding portion) ≤ 7 characterized in that the external light shielding film. An optical filter comprising the external light shielding film of any one of claims 1 to 5.

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