KR20160030854A

KR20160030854A - Method for quantitatively evaluating glare

Info

Publication number: KR20160030854A
Application number: KR1020150126817A
Authority: KR
Inventors: 겐 후루이
Original assignee: 다이니폰 인사츠 가부시키가이샤
Priority date: 2014-09-11
Filing date: 2015-09-08
Publication date: 2016-03-21
Also published as: TWI682157B; JP2016057227A; JP6471435B2; KR102022142B1; TW201627649A

Abstract

The present invention provides a method for quantitatively evaluating glare, which is highly correlated with the glare when the antiglare film is visually observed in the oblique direction, without actually evaluating the degree of occurrence of glare on the antiglare film in the oblique direction . According to one aspect of the present invention, there is provided an optical recording medium comprising a light-transmitting base material 31 and an antiglare layer 32 formed on the light-transmitting base material 31 and having an uneven surface 32A, Wherein the surface 30A of the antiglare film 30 is measured from the lattice matrix filter 20 disposed on the side of the back surface 30B of the antiglare film 30 to the quantitative evaluation of the glare of the antiglare film 30. [ The light from the white light source 10 is incident on the antiglare film 30 from the side of the back surface 30B of the antiglare film 30 through the matrix filter 20 and the antiglare film 30 30, and introduces the transmitted light as an image, calculates a standard deviation of the variation of the luminance distribution based on the introduced image, and sets the obtained standard deviation as a glare value , A quantitative evaluation method of glare is provided.

Description

[0001] METHOD FOR QUANTITATIVELY EVALUATING GLARE [0002]

The present invention relates to a quantitative evaluation method of glare.

An image display surface of an image display device such as a liquid crystal display (LCD), a cathode ray tube display (CRT), a plasma display (PDP), a light emitting device display (ELD), and a field emission display (FED) And an antiglare film having irregularities on the surface and an antireflection film having an antireflection layer on the outermost surface are provided in order to suppress the projection of the observer's background and the like.

The antiglare film scatters the external light on the uneven surface of the antiglare layer to suppress the projection of the background of the observer and the observer. The antiglare film mainly comprises a light-transmitting substrate and an antiglare layer formed on the light-transmitting substrate and having an uneven surface.

In the image display apparatus, glare may occur due to the influence of the uneven surface of the black matrix and the antiglare film. As a result, various methods for evaluating the glare of the antiglare film have been proposed (see Patent Documents 1 to 4).

Japanese Patent Application Laid-Open No. 2000-304648 Japanese Patent Application Laid-Open No. 2003-279485 Japanese Patent Laid-Open No. 2007-71723 Japanese Patent Application Laid-Open No. 2009-236621

Glare may have a stronger side when viewing the screen in the oblique direction with an angle of 30 degrees or more with respect to the normal direction of the screen than when viewed from the front side with the naked eye, Even when the glare is not confirmed, the glare may be confirmed when the screen is viewed with the naked eye in the oblique direction.

In particular, in an ultra-high-precision image display device having a horizontal pixel number of 3000 or more called 4K2K (3840 horizontal pixels / 2160 vertical pixels)), glare easily occurs when the screen is viewed from the oblique direction with the naked eye.

With respect to the glare problem when the screen is viewed with the naked eye in such an oblique direction, the glare evaluation methods of Patent Documents 1 to 4 have no correlation with the glare when viewed from the oblique direction, and can not be properly evaluated.

On the other hand, even if the glare of the antiglare film is photographed and evaluated in the oblique direction using the CCD camera in the oblique direction, the CCD camera can not be focused on the entire evaluation target, and therefore evaluation can not be appropriately performed. Further, in practice, it is desired to visually evaluate whether glare occurs in the antiglare film in the oblique direction or not, because there is a possibility that a deviation may occur according to individual differences, and therefore, an objective quantitative evaluation method is required.

The present invention has been made to solve the above problems. That is, there is provided a method of quantitatively evaluating glare, which is highly correlated with the glare when the antiglare film is visually observed in the oblique direction, without actually evaluating the degree of occurrence of glare on the antiglare film in the oblique direction .

According to one aspect of the present invention, there is provided a quantitative evaluation method of glare of an antiglare film having a light-transmitting base material and an antiglare layer formed on the light-transmitting base material and having an uneven surface, The surface of the film was irradiated with light from a white light source through the matrix filter in a state that the surface of the film was spaced by 2.0 mm or more from the lattice matrix filter disposed on the back side of the antiglare film, Capturing the transmitted light emitted from the surface of the antiglare film, introducing the transmitted light as an image, obtaining a standard deviation of the variation of the luminance distribution based on the introduced image, and calculating a value of the obtained standard deviation as A quantitative evaluation method of the glare is provided.

According to the quantitative evaluation method of glare according to an embodiment of the present invention, since the glare is evaluated while the surface of the antiglare film is separated from the matrix filter by 2.0 mm or more, the degree of glare in the antiglare film is actually measured visually Even if it is not evaluated, the degree of glare can be confirmed by numerical values when the antiglare film is visually observed in the oblique direction.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram for explaining a quantitative evaluation method of glare according to an embodiment; Fig.
2 is a schematic structural view of the antiglare film shown in Fig.
3 is a schematic structural view of another antiglare film.

Hereinafter, a quantitative evaluation method of glare of an antiglare film according to an embodiment will be described with reference to the drawings. Fig. 1 is a view for explaining a quantitative evaluation method of glare of an antiglare film according to the present embodiment, Fig. 2 is a schematic constitutional view of an antiglare film shown in Fig. 1, and Fig. 3 is a schematic constitutional view of another antiglare film . In the present specification, terms such as "film", "sheet", "plate" and the like are not distinguished from each other only on the basis of the difference in designation. Thus, for example, the term " film " is a concept including a member which may also be referred to as a sheet or a plate. As one specific example, the "antiglare film" also includes a member called "antiglare sheet" or "dummy plate".

First, as shown in Fig. 1, a white light source 10, a lattice matrix filter 20, an antiglare film 30, and an image pickup device 40 are arranged in this order. By using a combination of the white light source 10 and the matrix filter 20, a liquid crystal display can be reproduced in a pseudo manner.

As the white light source 10, a white surface light source is preferable in order to more faithfully reproduce a pseudo liquid crystal display. As a white light source, for example, LIGHTBOX manufactured by HAKUBA can be mentioned. The white light source 10 is arranged slightly spaced from the matrix filter 20.

The lattice-shaped matrix filter 20 shown in Fig. 1 is formed of a black matrix. Specifically, for example, the matrix filter 20 is composed of only a black matrix formed with a length of 85 nm, a width of 65 nm, a thickness of 1 nm, and a pitch of 127 μm × 127 μm (200 ppi) And functions as a filter. Although a pseudo color filter is used as the matrix filter, a colored color filter may be used as the matrix filter.

The matrix filter 20 is formed on one surface of a light-permeable support plate 50 such as a glass plate. Specifically, the matrix filter 20 is formed on the surface 50A of the support plate 50 on the white light source 10 side.

1 and 2, the antiglare film 30 to be evaluated comprises a light-transmitting base material 31, an antiglare layer 32 formed on the light-transmitting base material 31 and having an uneven surface 32A, .

The surface 30A of the antiglare film 30 is an uneven surface reflecting the uneven surface 32A of the antiglare layer 32. [ 2 does not have a functional layer such as a low refractive index layer formed on the antiglare layer 32 so that the irregular surface 32A of the antiglare layer 32 is formed on the surface of the antiglare film 30 (30A). In addition, the functional layer 71 may be formed on the antiglare layer 32 like the antiglare film 70 shown in Fig. In this case, the surface 71A of the functional layer 71 is the surface 70A of the antiglare film 70. The "functional layer" is a layer intended to exhibit a certain function in the antiglare film, specifically, a layer for exerting functions such as antireflection property, antistatic property or antifouling property . The functional layer may be not only a single layer but also a laminate of two or more layers. In the case where a low refractive index layer having a refractive index lower than the refractive index of the antiglare layer 32 is used as the functional layer 71, the low refractive index layer has a thin film thickness. Therefore, on the surface of the low refractive index layer, The concavo-convex shape in Fig. Therefore, the concavo-convex shape on the surface 70A of the antiglare film 70 is substantially the concavo-convex shape on the uneven surface 32A of the antiglare layer 32. [

The surface 30A of the antiglare film 30 is separated from the matrix filter 20 disposed on the side of the back surface 30B of the antiglare film 30 by 2.0 mm or more. That is, the distance d shown in Fig. 1 is 2.0 mm or more. Here, in the present specification, "the surface of the antiglare film is spaced by 2.0 mm or more from the matrix filter" means that the antiglare film is spaced apart from the rear surface of the antiglare film in the direction normal to the back surface thereof, Means that the distance from the position where the antiglare film is formed to the side of the antiglare film of the matrix filter is 2.0 mm or more. Whether or not the distance is 2.0 mm or more may be determined by directly measuring the distance from the surface of the antiglare film to the side of the antiglare film on the side of the antiglare film. And the total thickness of the antiglare film and the member existing between them. The "back side" of the antiglare film in this specification means a side opposite to the surface of the antiglare film. In the present embodiment, the back surface 30B of the antiglare film 30 is a surface opposite to the surface on the side of the antiglare layer 32 in the light-transparent base material 31. [ When the antiglare film 70 is used, the matrix filter 20 is disposed on the back side 70B side of the antiglare film 70. Further, since the surface of the antiglare film is an uneven surface, the thickness of the antiglare film differs depending on the place, but the "thickness of the antiglare film" means that the thickness of the antiglare film is measured by 10 points and means the average value .

The lower limit of the distance between the matrix filter 20 and the surface 30A of the antiglare film 30 is preferably 3.0 mm or more. The upper limit of the distance between the matrix filter 20 and the surface 30A of the antiglare film 30 is preferably 10 mm or less and more preferably 8 mm or less. If the distance between the matrix filter and the antiglare film exceeds 10 mm, glare is less likely to be generated, and the glare may not be properly evaluated.

The distance between the matrix filter 20 and the surface 30A of the antiglare film 30 is set between the matrix filter 20 and the surface 30A of the antiglare film 30, A spacer 60 having transparency may be interposed. The spacer 60 may be a glass plate or the like. In this embodiment, the support plate 50 and the spacer 60 are in contact with each other.

When the matrix filter 20 is formed on the support plate 50 and the spacer 60 is interposed between the matrix filter 20 and the antiglare film 30, The distance between the matrix filter 20 and the antiglare film 30 can be reliably set to 2.0 mm or more.

In this embodiment, the support plate 50 and the spacer 60 are interposed between the matrix filter 20 and the antiglare film 30, but when the thickness of the support 50 is 2.0 mm or more, The distance between the matrix filter 20 and the surface 30A of the antiglare film 30 can be 2.0 mm or more so that the spacers 60 do not need to be interposed. If the distance between the matrix filter 20 and the surface 30A of the antiglare film 30 is 2.0 mm or more, an air layer may be interposed between the matrix filter 20 and the antiglare film 30, When the air layer is interposed, it is preferable that the matrix filter 20 and the antiglare film 30 are filled with a transparent medium other than the gas, because reflection at the interface may adversely affect the measurement. The antiglare film 30 is attached to the spacer 60 with a transparent pressure-sensitive adhesive (not shown).

The antiglare film 30 is provided with a light-transmitting base material 31 and an antiglare layer 32. The light-transmitting base material 31 is not particularly limited as far as it has light transmittance. For example, a cellulose acylate base, Based substrate, a polycarbonate substrate, an acrylate-based polymer substrate, a polyester substrate, or a glass substrate.

The thickness of the light-permeable base material 31 is not particularly limited, but it may be 5 占 퐉 or more and 1000 占 퐉 or less. The lower limit of the thickness of the light-transparent base material 31 is preferably 15 占 퐉 or more , And more preferably 25 m or more. The upper limit of the thickness of the light-transmitting base material 31 is preferably 80 占 퐉 or less from the viewpoint of thinning.

The antiglare layer 32 is a layer exhibiting antifogging properties. The antiglare layer 32 may exhibit flicker resistance and exhibit other functions. Specifically, the antiglare layer 32 may be a layer exhibiting antistatic properties and exhibiting functions such as hard coatability, antireflection property, antistatic property, or antifouling property, for example.

The thickness of the antiglare layer 32 is not particularly limited, but it is possible to set the thickness of the antiglare layer 32 to 1 m or more and 20 m or less. The thickness of the antiglare layer 32 is a value measured from an image of a section electron microscope (TEM, STEM) using image processing software. Here, since the surface of the antiglare layer is an irregular surface, the thickness of the antiglare layer means the thickness of the antiglare layer measured at 10 points, which means the average value.

As a method of forming the uneven surface 32A of the antiglare layer 32, for example, a method of forming an uneven surface by using a composition for an antiglare layer containing a curable resin precursor (A) as a binder resin after curing and fine particles, (B) a method of forming an uneven surface by a transfer method using a mold, (C) a method of forming an uneven surface by roughening the surface of the antiglare layer by sandblasting, or (D) To form an uneven surface. Of these, the method (A) described above is preferable in view of easiness of production. When the antiglare layer is formed by the method of (A) above, the antiglare layer contains a binder resin and fine particles.

The imaging device 40 is used for imaging the transmitted light emitted from the surface 30A of the antiglare film 30 but a CCD camera (Charge-Coupled Device camera) can be used as the imaging device 40 .

Although the distance between the antiglare film 30 and the image pickup device 40 is different depending on the resolution of the image pickup device 40, it is preferably 200 mm or more and 300 mm or less, for example. At the time of photographing, the focus of the image pickup device 40 is adjusted to the antiglare film 30, and the diaphragm is appropriately positioned.

The image pickup device 40 is electrically connected to an image processing apparatus 80 for performing image processing and the like and for obtaining a standard deviation of variations in the luminance distribution in the transmitted light.

The light from the white light source 10 is incident from the side of the back surface 30B of the antiglare film 30 via the matrix filter 20 and the antiglare film 30 30 by the image capturing device 40. The image capturing device 40 captures the transmitted light.

Then, the transmitted light obtained by photographing is introduced into the image processing apparatus 80 as an image. The introduced image is subjected to image processing so as to obtain an appropriate value in quantifying the glare. The image processing includes, for example, low-pass filtering, shading correction, and contrast emphasis. Image processing can be performed by image processing software such as ImagePro Plus ver.6.2 (manufactured by Media Cybernetics). Hereinafter, the case where ImagePro Plus ver.6.2 is used as the image processing software will be described.

In the image processing, first, an area to be subjected to image processing is selected for the introduced image. This is because only the portion where the anti-ghost film exists is subjected to image processing. Specifically, for example, an area of 200 x 160 pixels is selected.

Subsequently, in this area, an image of 8-bit gray scale is converted into 16-bit gray scale in order to prevent an underflow in calculation of image processing. Subsequently, the image is filtered to remove components derived from the black matrix pattern. This filtering is performed by applying a low-pass filter so that the matrix filter becomes unknown. Specifically, for example, a low-pass filter is selected from the emphasis tap of the filter command, and filtering is performed under the condition of 3 × 3, frequency 3, and intensity 10.

After filtering, shading correction is performed, and then contrast enhancement is performed. The emphasis of the contrast is processing for facilitating the viewing of the luminance distribution in evaluating the glare. Specifically, for example, the contrast is set at 96 and the luminance is set at 48.

The image thus obtained is converted into 8-bit grayscale, and the variation of the value for each pixel is calculated as a standard deviation value with respect to 150 x 110 pixels in the 8-bit grayscale. The glare property of the antiglare film can be evaluated by comparing the obtained glare value with a predetermined value. The smaller the glare value is, the smaller the glare value. Therefore, the glare value is preferably 14 or less, more preferably 12 or less. In the present specification, the term " oblique direction " means a direction in which an angle of not less than 30 degrees is left or right from the normal direction of the light-transmitting base material in the antiglare film.

In the present embodiment, the glare of the antiglare film 30 is evaluated in a state where the surface 30A of the antiglare film 30 is separated from the matrix filter 20 by 2.0 mm or more. Although the reason for this is not clear, the present inventors have found that when the glare of the antiglare film is evaluated while the surface 30A of the antiglare film 30 is separated from the matrix filter by 2.0 mm or more, We have found the surprising fact that it correlates with the evaluation of glare on the antiglare film when it is seen. Therefore, according to the present embodiment, the degree of glare when the antiglare film is viewed visually in the oblique direction can be confirmed by numerical values, without actually evaluating the glare generated in the anticorrosion film in the oblique direction.

An antiglare film having a glare value of 12 or less obtained by the evaluation method of the present embodiment is used in a built-in image display apparatus. In particular, an antiglare film having a number of horizontal pixels of 3000 or more called 4K2K (3840 horizontal pixels, 2160 vertical pixels) Is preferably used in an image display device of the present invention.

[Example]

In order to explain the present invention in detail, the present invention will be described with reference to the following examples, but the present invention is not limited to these examples.

&Lt; Preparation of composition for antiglare layer >

First, each component was blended so as to have the composition shown below to obtain a composition for an antiglare layer.

(Composition 1 for the antiglare layer)

Silica fine particles (octyl silane-treated fumed silica, average primary particle diameter 12 nm, manufactured by Nippon Aerosil Co., Ltd.): 0.5 parts by mass

Silica fine particles (methyl silane-treated fumed silica, average primary particle diameter 12 nm, manufactured by Nippon Aerosil Co., Ltd.): 0.2 parts by mass

Pentaerythritol tetraacrylate (PETTA) (product name: PETA, manufactured by Daicel-Cytec): 50 parts by mass

Urethane acrylate (trade name: "V-4000BA", manufactured by DIC): 50 parts by mass

Polymerization initiator (Irgacure 184, manufactured by BASF Japan): 5 parts by mass

Polyether-modified silicone (product name: TSF4460, manufactured by Momentive Performance Materials Ltd.): 0.025 parts by mass

Toluene: 70 parts by mass

Isopropyl alcohol: 40 parts by mass

Cyclohexanone: 40 parts by mass

(Composition 2 for the antiglare layer)

- Organic fine particles (spherical polyacryl-styrene copolymer particles, particle diameter 3.5 mu; refractive index 1.545, manufactured by Sekisui Chemical Co., Ltd.): 12 parts by mass

38 parts by mass of pentaerythritol triacrylate (trade name: KAYARAD-PET-30, manufactured by Nippon Kayaku Co., Ltd.)

· EO-modified triacrylate of isocyanuric acid (product name: "M-313", manufactured by Toagosei Co., Ltd.): 22 parts by mass

Inorganic fine particles (silica having a reactive functional group introduced on its surface, average primary particle diameter 12 nm, solvent MIBK, solid content 30%, manufactured by Nissan Kagaku Co., Ltd.): 120 parts by mass

Toluene: 135 parts by mass

(Composition 3 for the antiglare layer)

20 parts by mass of organic fine particles (spherical polyacryl-styrene copolymer particles, particle diameter 5 mu m, refractive index 1.525, manufactured by Sekisui Chemical Co., Ltd.)

· Isocyanuric acid EO-modified triacrylate (product name: "M-313", manufactured by Toagosei Co., Ltd.): 22 parts

Toluene: 135 parts by mass

(Composition 4 for an antiglare layer)

· Organic fine particles (hydrophilized acrylic-styrene copolymer particles, average particle diameter 2.0 μm, refractive index 1.55, manufactured by Sekisui Chemical Co., Ltd.): 3 parts by mass

Fumed silica (treated with methylsilane, average particle diameter 12 nm, manufactured by Nippon Aerosil Co., Ltd.): 1 part by mass

Pentaerythritol tetraacrylate (PETTA) (product name: PETA, manufactured by Daicel-Cytec): 60 parts by mass

Urethane acrylate (product name: UV1700B, manufactured by Nippon Goisha Chemical Co., Ltd., weight average molecular weight: 2000, number of functional groups: 10): 40 parts by weight

Polyether-modified silicone (TSF4460, manufactured by Momentive Performance Materials): 0.025 parts by mass

Toluene: 105 parts by weight

Isopropyl alcohol: 30 parts by mass

Cyclohexanone: 15 parts by mass

(Composition 5 for antiglare layer)

Organic fine particles (spherical polystyrene particles, particle size 3.5 mu; refractive index 1.59, manufactured by Soeken Kagaku Co., Ltd.): 12 parts by mass

90 parts by mass of pentaerythritol triacrylate (trade name: KAYARAD-PET-30, manufactured by Nippon Kayaku Co., Ltd.)

Acrylic polymer (molecular weight: 75,000, manufactured by Mitsubishi Rayon Co., Ltd.): 10 parts by mass

Polymerization initiator (Irgacure 184, manufactured by BASF Japan): 3 parts by mass

Toluene: 145 parts by mass

Cyclohexanone: 60 parts by mass

(Composition 6 for the antiglare layer)

Inorganic fine particles (gel method monodisperse silica, small number of treated water, average particle diameter (laser diffraction scattering method) 4.1 mu m, Fuji Silicia Kakaku Co., Ltd.): 14 mass parts

· 100 parts by mass of pentaerythritol triacrylate (trade name: KAYARAD-PET-30, manufactured by Nippon Kayaku Co., Ltd.)

Polyether-modified silicone (TSF4460, manufactured by Momentive Performance Materials): 0.2 parts by mass

Toluene: 150 parts by weight

MIBK: 35 parts by mass

&Lt; Preparation of composition for low refractive index layer &

Each component was blended so as to have the composition shown below to obtain a composition for a low refractive index layer.

(Composition for low refractive index layer)

(Solid content of hollow silica fine particles: 20 mass%, solution: methyl isobutyl ketone, average particle diameter: 50 nm): 40 mass parts

Pentaerythritol triacrylate (PETA) (product name: PETIA, manufactured by Daicel-Cytec): 10 parts by mass

Polymerization initiator (Irgacure 127, manufactured by BASF Japan): 0.35 parts by mass

Modified silicone oil (X22164E; Shin-Etsu Chemical Co., Ltd.): 0.5 parts by mass

Methyl isobutyl ketone (MIBK): 320 parts by mass

Propylene glycol monomethyl ether acetate (PGMEA): 161 parts by mass

A triacetylcellulose resin film (TD60UL, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 60 占 퐉 as a light-transmitting base material was prepared, and the antiglare layer composition 1 was coated on one side of the triacetylcellulose resin film to form a coating film. Subsequently, dry air at 50 DEG C was passed through the formed coating film for 15 seconds at a flow rate of 0.2 m / s, and then dried at 70 DEG C for 30 seconds at a flow rate of 10 m / s and dried to evaporate the solvent in the coating film , And an ultraviolet ray was irradiated under a nitrogen atmosphere (oxygen concentration: 200 ppm or less) so that the accumulated light quantity was 100 mJ / cm 2 to cure the coating film to form an antiglare layer having a thickness of 4.0 탆 .

In the sample 2, an antiglare film was prepared in the same manner as in the sample 1, except that the composition for the antiglare layer 2 was used in place of the composition for the antiglare layer 1 and the thickness at the time of curing of the antiglare layer was 5.0 탆.

In the sample 3, an antiglare film was prepared in the same manner as in the sample 1 except that the composition for an antiglare layer 3 was used in place of the composition for an antiglare layer 1, and the thickness at the time of curing of the antiglare layer was 7.0 탆.

In Sample 4, an antiglare film was prepared in the same manner as in Sample 1 except that the composition for an antiglare layer 4 was used in place of the composition for a antiglare layer 1.

In the sample 5, an antiglare film was prepared in the same manner as in the sample 1 except that the composition for an antiglare layer 5 was used in place of the composition for an antiglare layer 1, and the thickness at the time of curing of the antiglare layer was 4.5 탆.

In the sample 6, an antiglare film was prepared in the same manner as in the sample 1 except that the composition for an antiglare layer 6 was used in place of the composition for an antiglare layer 1, and the thickness at the time of curing of the antiglare layer was 2.0 탆.

In Sample 7, an antiglare layer was formed on the triacetylcellulose resin film in the same manner as in Sample 1, except that the amount of ultraviolet light was 50 mJ / cm 2. Subsequently, a composition for a low refractive index layer was applied to the surface of the antiglare layer so as to have a film thickness of 0.1 mu m after drying (40 DEG C x 1 minute), and then exposed to ultraviolet rays at an integrated light quantity of 100 mJ / And irradiated with ultraviolet rays and cured to form a low refractive index layer to prepare an antiglare film for Sample 7.

In each of the antiglare films of Samples 1 to 7, a glass plate having a thickness of 3 mm was bonded to the back surface of the antiglare film (the side opposite to the side where the antiglare layer of the triacetylcellulose resin film was formed) with a transparent pressure-sensitive adhesive. The glass surface on which the antiglare film on the glass plate was not bonded and the glass surface on which the black matrix was not formed on the glass plate having the thickness of 0.7 mm on which the black matrix of 200 ppi was formed on one side was joined with water. That is, in Samples 1 to 7, the surface of the antiglare film was separated from the black matrix by 3.76 mm. Light of a white surface light source (LIGHTBOX produced by HAKUBA, average luminance of 1000 cd / m 2) was irradiated from the black matrix side to the thus obtained laminate, and glare was generated in a pseudo manner. This was photographed by a CCD camera (KP-M1, C mount adapter, a contact ring; PK-11A Nikon, camera lens: 50 mm, F1.4s NIKKOR) from the antiglare film side. The distance between the CCD camera and the antiglare film was 250 mm, and the focus of the CCD camera was adjusted to the antiglare film. An image photographed with a CCD camera was introduced into a personal computer, and analyzed with image processing software (ImagePro Plus ver. 6.2; manufactured by Media Cybernetics) as follows. First, an area of 200 x 160 pixels was selected from the introduced image, and in this area, it was converted into 16 bit gray scale. Subsequently, a low-pass filter was selected from the emphasis tap of the filter command, and the filter was placed under conditions of 3x3, frequency 3, and intensity 10. Thereby removing components derived from the black matrix pattern. Subsequently, planarization was selected, and shading correction was performed under the condition of background: darkness and object width 10. Then, contrast was emphasized by setting the contrast to 96 and the brightness to 48 with the contrast emphasizing command. The obtained image is converted into 8-bit gray scale, and the variation of the value for each pixel is calculated as a standard deviation value with respect to 150 x 110 pixels of the obtained image. The smaller the glare value, the less glare it can be.

In each of the antiglare films of Samples 1 to 7, the back surface of the antiglare film was bonded to a glass surface on which a black matrix of 200 ppi was formed on one side and a 0.7 mm thick glass plate on which a black matrix was not formed with a transparent pressure-sensitive adhesive. That is, in Samples 1 to 7, the surface of the antiglare film was separated from the black matrix by 0.76 mm. Light of a white surface light source (LIGHTBOX produced by HAKUBA, average luminance of 1000 cd / m 2) was irradiated from the black matrix side to the thus obtained laminate, and glare was generated in a pseudo manner. This was photographed by a CCD camera (KP-M1, C mount adapter, close-up ring; PK-11A Nikon, camera lens: 50 mm, F1.4s NIKKOR) from the antiglare film side. The distance between the CCD camera and the antiglare film was 250 mm, and the focus of the CCD camera was adjusted to the antiglare film. An image photographed with a CCD camera was introduced into a personal computer, and analyzed with image processing software (ImagePro Plus ver. 6.2; manufactured by Media Cybernetics) as follows. First, an area of 200 x 160 pixels was selected from the introduced image, and in this area, it was converted into 16-bit gray scale. Next, a low-pass filter was selected from the emphasis tap of the filter command, and the filter was placed under the conditions of 3x3, the number of times 3, and the intensity of 10. Thereby removing components derived from the black matrix pattern. Subsequently, planarization was selected, and shading correction was performed under the condition of background: darkness and object width 10. Then, contrast was emphasized by setting the contrast to 96 and the brightness to 48 with the contrast emphasizing command. The obtained image is converted into 8-bit gray scale, and the variation of the value for each pixel is calculated as a standard deviation value with respect to 150 x 110 pixels of the obtained image.

&Lt; Evaluation of Glare by the naked eye &

In each of the antiglare films of Samples 1 to 7, glare was visually evaluated as follows. A white plate light source with a luminance of 1500 cd / m 2, a glass plate with a thickness of 0.7 mm on which a black matrix of 200 ppi was formed on one side, and an antiglare film were stacked in this order from the bottom to a triacetyl Visual evaluation was carried out from a direction in which the cellulosic resin film was inclined 45 degrees to the left and right from the normal direction. The degree of glare was observed, and it was judged to be four stages of 1 to 4. Here, 1, 2, 3, and 4 are listed in order of glare. That is, the largest glare becomes 1 and the smallest glare becomes four.

The results are shown in Table 1 below.

As shown in Table 1, the results of the glare evaluation method of the comparative example did not correspond to the results of the glare evaluation by the naked eye. On the other hand, the results of the glare evaluation method according to the embodiment corresponded to the results of the glare evaluation with the naked eye. Thus, according to the glare evaluation method of the embodiment, it is possible to evaluate how much glare occurs when the glare film is visually observed in the oblique direction, without actually evaluating the degree of glare on the glare film in the oblique direction .

10: White light source
20: Matrix filter
30, 70: Antiglare film
30A, 70A: surface
30B and 70B:
31: light-transmitting substrate
32: Visible layer
32A, 71A: uneven surface
40:
50: Support plate
60: Spacer
71: Functional layer

Claims

A quantitative evaluation method of glare of an antiglare film having a light-transmitting base material and an antiglare layer formed on the light-transmitting base material and having an uneven surface,
The surface of the antiglare film is irradiated with light from the white light source through the matrix filter in a state in which the surface of the antiglare film is separated from the lattice matrix filter disposed on the back side of the antiglare film by 2.0 mm or more, The method according to any one of claims 1 to 3, further comprising the steps of: introducing, from the back side of the film, the transmitted light emitted from the surface of the antiglare film, introducing the transmitted light as an image, obtaining a standard deviation of the fluctuation of the luminance distribution based on the introduced image, As a glare value.

The method according to claim 1,
Wherein a spacer having light transmittance is disposed between the matrix filter and the antiglare film.

The method according to claim 1,
And calculating a standard deviation of the variation of the luminance distribution after the image of the introduced image is subjected to image processing.

The method according to claim 1,
Wherein the matrix filter is constituted by a black matrix.

The method according to claim 1,
And the photographing of the transmitted light is performed by a CCD camera.