JP2009122371A - Anti-glare film and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-glare film sufficiently suppressing degradation of visibility due to whitening or glaring, and having excellent anti-glare performance of preventing reflection, and to provide an image display device using the anti-glare film. <P>SOLUTION: The anti-glare film includes a resin base film 101, and an anti-glare layer 102 having an irregular surface, which is laminated on a surface of the resin base film 101. The anti-glare layer 102 is made of a transparent resin 104 having light diffusing particles 103 dispersed therein, and the light diffusing particles 103 have a non-spherical shape having an aspect ratio of 1 or more, the aspect ratio being represented by L<SB>max</SB>/L<SB>ver</SB>, wherein L<SB>max</SB>is the maximum length of a project plane when the particle is projected so that the projected area is minimized, and L<SB>ver</SB>is the maximum length of the project plane in a direction orthogonal to the L<SB>max</SB>direction. The irregular shape on the surface of the anti-glare layer 102 is formed by an embossing method using a metal die. The image display device uses this anti-glare film. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an antiglare film that can be suitably applied to an image display device and the like, and an image display device using the same, and more specifically, an antiglare film that is sufficiently prevented from glare and whitish and has excellent visibility, and The present invention relates to an image display device using the antiglare film.

  In an image display device such as a liquid crystal display, a plasma display panel, a cathode ray tube (CRT) display, and an organic electroluminescence (EL) display, visibility is significantly impaired when external light is reflected on the display surface. Conventionally, in order to prevent such reflection of external light, televisions and personal computers that emphasize image quality, video cameras and digital cameras that are used outdoors with strong external light, and mobile phones that display using reflected light In a telephone or the like, a film layer for preventing external light from being reflected is provided on the surface of an image display device. As such a film layer, an anti-glare treatment is performed to scatter incident light by blurring the incident light by forming fine irregularities on the film and the surface subjected to the antireflection treatment utilizing interference by the optical multilayer film. Films are commonly used. Among these, the former non-reflective film needs to form a multilayer film having a uniform optical film thickness, and thus increases the cost. On the other hand, since the latter anti-glare film can be manufactured comparatively cheaply, it is widely used for applications such as large monitors and personal computers.

  For example, in Patent Document 1, a translucent resin containing translucent fine particles (fillers) such as styrene beads having a particle diameter of 0.5 to 5 μm and cohesive silica is applied to the surface of a transparent substrate film. The production of an antiglare film is described. However, since the filler used is amorphous such as beads (spherical) or cohesive silica, there is a problem that a sufficient light scattering effect in the translucent resin layer by the filler cannot be obtained. It was. If the light scattering effect is insufficient, when an anti-glare surface consisting of irregularities is provided on the outermost surface of a high-definition image display device, the pixels and the irregularities of the anti-glare surface interfere with each other, so-called “glare” occurs. The sharpness of the image is lowered, and the visibility of the display image is lowered.

  In addition, as described in Patent Document 1, a resin solution in which a filler is dispersed is applied onto a base film, and the coating film thickness is adjusted to cause random unevenness by exposing the filler to the coating film surface. According to the method of forming on the substrate film, the arrangement and shape of the surface irregularities are affected by the dispersion state and application state of the filler in the resin solution, so it is difficult to obtain the surface irregularities as intended. In addition, there is a problem that sufficient anti-glare performance cannot be obtained with a low haze. Furthermore, when such a conventional anti-glare film is disposed on the surface of an image display device, there is a problem that the entire display surface becomes whitish due to scattered light, and the display becomes cloudy, so-called whitening is likely to occur. It was.

On the other hand, Patent Document 2 describes that a flat scatterer is dispersed in a translucent resin to form a light diffusion film, and Patent Document 3 describes that flat (unshaped) resin particles are provided. A method of manufacturing is described.
JP 11-326608 A JP 2003-195015 A JP 2004-27008 A

  The present invention has been made in view of the above-described problems of the prior art, and the deterioration of visibility due to whitishness and glare is sufficiently suppressed. An object is to provide a glare film and an image display device using the antiglare film.

The antiglare film according to the present invention is an antiglare film comprising a resin base film and an antiglare layer having a concavo-convex shape on the surface laminated on the resin base film surface. It is a layer made of a transparent resin in which non-spherical light diffusing particles having an aspect ratio exceeding 1 represented by the following formula (1) are dispersed, and the uneven shape of the antiglare layer surface uses a metal mold. It is an anti-glare film formed by the embossing method.
Aspect ratio = L _max / L _ver (1)
Here, L _max is the maximum length of the projection surface when the projection area of the light diffusing particles is minimized, and L _ver is a direction orthogonal to the L _max direction on the projection surface. The maximum length.

  In the antiglare film of the present invention, the uneven shape of the antiglare layer surface is preferably a surface uneven shape mainly formed by a transparent resin, and more preferably, the light diffusing particles are embedded in the antiglare layer. Yes.

  The aspect ratio of the light diffusing particles is preferably in the range of 1.2 to 2. Examples of the shape of the light diffusing particles include a meteorite shape, a convex lens shape, and a shape equivalent thereto. The light diffusing particles are preferably made of an organic resin. The light diffusing particles are preferably contained within a range of 10 to 35 parts by weight with respect to 100 parts by weight of the transparent resin.

  The transparent resin is preferably a photocurable resin or a thermoplastic resin. Further, the refractive index difference between the transparent resin and the light diffusing particles is preferably in the range of 0.02 to 0.5.

  The haze of the antiglare film of the present invention is preferably in the range of 2 to 40%. The antiglare film of the present invention may further have a low reflection film on the uneven surface of the antiglare layer.

  According to the present invention, there is provided an image display device comprising at least the antiglare film described above and an image display element, wherein the antiglare film is disposed on the viewing side of the image display element.

  The antiglare film of the present invention has excellent antiglare performance such as prevention of reflection and prevention of reflection due to sufficiently reduced visibility due to whitishness and glare. And the image display apparatus which has arrange | positioned the anti-glare film of this invention is excellent in brightness, anti-glare performance, and visibility.

<Anti-glare film>
FIG. 1 is a schematic cross-sectional view showing a preferred example of the antiglare film of the present invention. As shown in FIG. 1, the antiglare film of the present invention includes a resin base film 101 and an antiglare layer 102 having an uneven shape on the surface, which is laminated on the surface of the resin base film 101. The antiglare layer 102 is made of a transparent resin 104 in which non-spherical light diffusing particles 103 are dispersed. In the present invention, the surface unevenness of the antiglare layer 102 is formed by an embossing method using a metal mold.

  As the transparent resin constituting the antiglare layer, a substantially optically transparent ultraviolet curable resin, a photocurable resin such as a visible light curable resin, and a thermoplastic resin can be preferably used. By using these resins, irregularities can be formed on the surface of the antiglare layer by an embossing method such as a UV embossing method or a hot embossing method described later.

  The ultraviolet curable resin is not particularly limited, and a conventionally known resin can be used. For example, one or more polyfunctional acrylates such as trimethylolpropane triacrylate and pentaerythritol tetraacrylate, and “Irgacure 907”, “Irgacure 184” (above, manufactured by Ciba Specialty Chemicals), “ A mixture with a photopolymerization initiator such as “Lucirin TPO” (manufactured by BASF) can be used as an ultraviolet curable resin. In addition, a visible light curable resin that can be cured with visible light having a wavelength longer than that of ultraviolet light can be used by appropriately selecting a photopolymerization initiator instead of the ultraviolet curable resin.

  The thermoplastic resin may be any material as long as it is substantially transparent, for example, polymethyl methacrylate, polycarbonate, polyethylene terephthalate, triacetyl cellulose, thermoplastics such as amorphous cyclic polyolefin using norbornene compounds as monomers. Resins can be mentioned.

In the present invention, non-spherical particles having an aspect ratio exceeding 1 represented by the following formula (1) are used as the light diffusing particles dispersed in the antiglare layer.
Aspect ratio = L _max / L _ver (1)
Here, L _max is the maximum length of the projection surface when the projection area of the light diffusing particles is minimized, and L _ver is a direction orthogonal to the L _max direction on the projection surface. The maximum length. By using such non-spherical light diffusing particles, glare can be effectively suppressed. In order to suppress glare more effectively, the aspect ratio is preferably 1.2 to 2. When the aspect ratio exceeds 2, the particles tend to protrude from the surface of the antiglare layer when the uneven shape of the surface of the antiglare layer is formed by the embossing method.

2 is a schematic view showing an example of the shape of the non-spherical light diffusing particles according to the present invention, FIG. 2 (a) is a schematic perspective view, FIG. 2 (b) is a schematic plan view, and FIG. c) is a schematic top view. In the non-spherical particles illustrated in FIG. 2, L _max is a length indicated by B in FIG. 2, and L _ver is a length indicated by A. The non-spherical light diffusing particles used in the present invention may have a convex lens shape (a shape obtained by dividing a meteorite shape in half) or a shape equivalent to these in addition to the meteorite shape as shown in FIG. .

  The non-spherical light diffusing particles are preferably particles made of an organic resin. Specific examples of light diffusing particles made of an organic resin preferably used include, for example, melamine resin beads (refractive index 1.57), acrylic resin (polymethyl methacrylate) beads (refractive index 1.49), methyl Methacrylate-styrene copolymer beads (refractive index 1.50-1.59), polycarbonate beads (refractive index 1.55), polyethylene beads (refractive index 1.53), polyvinyl chloride beads (refractive index 1.46) And silicone resin beads (refractive index: 1.43 to 1.50). The refractive index of the light diffusing particles needs to have a value different from the refractive index of the transparent resin in order to impart a light diffusing function to the antiglare layer. The difference in refractive index between the transparent resin and the light diffusing particles is preferably 0.02 to 0.5, more preferably 0.02 to 0.05. When the difference in refractive index is less than 0.02, a sufficient light diffusion function cannot be imparted, and when the difference in refractive index exceeds 0.5, the light transmittance is reduced or colored. There is a tendency to cause problems such as. The materials of the transparent resin and the light diffusing particles are appropriately selected in consideration of the preferable refractive index difference.

  The average particle diameter of the non-spherical light diffusing particles is preferably an average particle diameter in terms of a volume equivalent sphere diameter measured by a Coulter method, and is preferably 3 to 30 μm, more preferably 3 to 12 μm. When the average particle size of the non-spherical light diffusing particles is less than 3 μm, the scattered light intensity on the wide angle side increases, and as a result, the contrast tends to be lowered when applied to an image display device. When the average particle size exceeds 30 μm, the required scattering effect may not be obtained.

  In the antiglare layer, the non-spherical light diffusing particles are preferably contained in an amount of 10 to 35 parts by weight with respect to 100 parts by weight of the transparent resin. When the content of the non-spherical light diffusing particles is less than 10 parts by weight, a sufficient light scattering effect cannot be obtained and glare tends to occur. In addition, when the content of non-spherical light diffusing particles exceeds 35 parts by weight, the light scattering effect is increased, resulting in an increase in haze, and the screen becomes dark when applied to an image display device, so that visibility is improved. And the contrast tends to decrease. The content of the non-spherical light diffusing particles is more preferably 15 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the transparent resin. In the case where the transparent resin is a resin composition containing, for example, a photopolymerization initiator, the content of the non-spherical light diffusing particles is a value relative to 100 parts by weight of the resin component in the resin composition. .

  The thickness of the antiglare layer is not particularly limited, but is preferably about 5 to 30 μm, more preferably 10 to 25 μm. When the thickness of the antiglare layer is less than 5 μm, the non-spherical light diffusing particles protrude from the surface of the antiglare layer, adversely affect the optical properties, or the light scattering effect cannot be obtained and glare occurs. There is a tendency to do. On the other hand, when the thickness of the antiglare layer exceeds 30 μm, the film tends to break or the film curls due to the curing shrinkage of the transparent resin when the antiglare layer is formed, and the productivity tends to decrease.

  The said resin base film can be comprised from transparent resin. The transparent resin that can be used for the resin base film is only required to be substantially optically transparent. For example, polymethyl methacrylate, polycarbonate, polyethylene terephthalate, triacetyl cellulose, polypropylene, norbornene-based compounds are used as monomers. Mention may be made of thermoplastic resins such as amorphous cyclic polyolefins. A resin base film can be obtained by forming such a resin into a film using a solvent casting method or an extrusion method. The transparent resin used for the resin base film and the transparent resin used for the antiglare layer may be the same or different materials.

  The thickness of the resin base film is preferably 30 μm or more and 120 μm or less, and more preferably 40 μm or more and 80 μm or less. When the thickness of the resin base film is less than 30 μm, the film curls due to the curing shrinkage of the transparent resin when the antiglare layer is formed, and the productivity is lowered. Moreover, it is not preferable that the thickness of the resin base film exceeds 120 μm from the viewpoint of the recent demand for thinning of the image display device and the cost.

The antiglare film of the present invention, which is a laminate of a resin base film and an antiglare layer having an uneven surface shape, can be produced, for example, by the following method.
(1) After applying a photocurable resin-containing liquid in which non-spherical light diffusing particles are dispersed on the surface of the resin base film and pressing a metal mold against the formed photocurable resin layer, A method in which light irradiation is performed in a state where a metal mold is in close contact, the photocurable resin layer is cured, and then a resin base film on which a cured product layer (antiglare layer) is laminated is peeled from the metal mold.
(2) After dispersing non-spherical light diffusing particles in the molten thermoplastic resin, it is formed into a film shape and bonded to a resin base film, and then this laminated film is heated in a metal mold. A method of imparting a surface irregularity shape to the thermoplastic resin layer.

  In any of the above methods, an antiglare film is obtained by using a metal mold having a concavo-convex shape on the surface and transferring the surface concavo-convex shape of the metal mold to the film. The metal mold shape transfer method shown in the above (1) is a so-called “UV embossing method”, and the metal mold shape transfer method shown in the above (2) is “hot embossing”. It is what is called the "law". In the present invention, a photocurable resin other than an ultraviolet curable resin such as a visible light curable resin can be used as the photocurable resin, but a photocurable resin other than the ultraviolet curable resin is used. In some cases, it is included in the “UV embossing method”.

  In the UV embossing method, a photocurable resin layer is formed on the surface of a resin base film, and the photocurable resin layer is cured while being pressed against the uneven surface of the mold, so that the uneven shape of the mold is photocurable. Transferred to the resin layer. More specifically, a resin liquid containing a photocurable resin such as an ultraviolet curable resin and non-spherical light diffusing particles is applied onto a resin base film, and the formed photocurable resin layer is made of metal. In the state of being in close contact with the uneven surface of the mold, light such as ultraviolet rays is irradiated from the resin base film side to cure the photocurable resin layer. Then, the shape of a metal mold is transcribe | transferred to the said hardened | cured material layer by peeling the resin base film in which the hardened | cured material layer (anti-glare layer) was formed from the metal metal mold | die.

  On the other hand, in the hot embossing method, first, a molten thermoplastic resin is prepared, and non-spherical light diffusing particles are dispersed therein to obtain a resin liquid, which is then formed into a film shape. Examples of the method for forming a film include a solvent casting method and an extrusion method. Next, the resin substrate film is bonded to the thermoplastic resin film with or without using an adhesive or an adhesive. Next, the laminated film is heated to soften the thermoplastic resin film, and then pressed against the uneven surface of the metal mold to transfer the surface uneven shape of the metal mold to the thermoplastic resin film. Among the above embossing methods, the UV embossing method is preferable from the viewpoint of productivity.

  According to the method for forming surface irregularities using the embossing method as described above, the arrangement and shape of the irregularities can be adjusted regardless of the dispersion state of the non-spherical light diffusing particles in the resin liquid and the application state of the resin liquid. By controlling only the arrangement and shape of the surface irregularities of the mold, the arrangement and shape of the irregularities formed on the antiglare film can be controlled, so that a desired surface irregularity shape can be obtained. Further, the uneven shape on the surface of the antiglare layer formed by the embossing method is a transferred shape of the uneven shape of the metal mold, and is a surface uneven shape formed mainly by the transparent resin constituting the antiglare layer. That is, according to the surface irregularity forming method using the embossing method, the non-spherical light diffusing particles are embedded in the anti-glare layer, so that the non-spherical light diffusing particles are formed on the surface of the anti-glare layer. It is possible to avoid or suppress the problem of protruding and making the uneven surface shape uneven. Therefore, according to the surface unevenness forming method using the embossing method, it is possible to form a desired uniform surface unevenness shape, thereby improving the antiglare property of the antiglare film.

  As a method for producing a metal mold having an uneven surface shape used for the embossing method, for example, as described in JP-A-2007-156132, the average particle diameter is in the range of 15 to 35 μm on the polished metal surface. It is possible to preferably use a method of forming irregularities by hitting the fine particles on the surface and performing electroless nickel plating on the irregular surfaces. In this method, the ruggedness formed by hitting the fine particles is dulled (relaxed) by electroless nickel plating, so that there is substantially no flat portion, and a favorable optical characteristic is exhibited. A metal mold having a concavo-convex shape suitable for obtaining a dazzling film can be obtained.

  Japanese Patent Laid-Open No. 2007-237541 discloses a process in which copper plating or nickel plating is applied to the surface of a metal substrate, the plated surface is polished, fine particles are applied to the polished surface to form unevenness, and the uneven shape is blunted. A method is described in which chrome plating is applied to the concavo-convex surface. Also by this method, a metal mold having a concavo-convex shape suitable for obtaining an antiglare film exhibiting preferable optical properties can be obtained and preferably used.

  The shape of the metal mold may be a flat metal plate or a cylindrical metal roll. If a metal mold | die is produced using a metal roll, an anti-glare film can be manufactured in a continuous roll shape.

  As described above, the antiglare film of the present invention which is a laminate of the resin base film and the antiglare layer having an uneven surface shape preferably has a haze of 2 to 40%, and 2 to 15%. More preferably. When the haze is less than 2%, the glare-suppressing effect is insufficient, and when it is more than 40%, it is not preferable because a decrease in visibility and a significant decrease in contrast ratio due to occurrence of whitening are confirmed. The haze of the antiglare film is measured in accordance with JIS K 7136 by bonding the antiglare film and the glass substrate using an optically transparent adhesive so that the uneven surface becomes the surface. .

  The antiglare film of the present invention has a reflectance R (30) at a reflection angle of 30 ° of 0.04% to 0.2% when light is incident from the antiglare layer side at an incident angle of 30 °. The reflectance R (40) at a reflection angle of 40 ° is preferably 0.005% or more and 0.02% or less, and the reflectance R (50) at a reflection angle of 50 ° is preferably 0.0015% or less. . By making the reflectance R (30), the reflectance R (40) and the reflectance R (50) within the above ranges, the anti-glare is more effectively suppressed while showing excellent anti-glare performance. A film is provided.

  Here, the reflectance for each angle when light is incident at an incident angle of 30 ° from the antiglare layer side will be described. FIG. 3 is a perspective view schematically showing an incident direction and a reflection direction of light from the antiglare layer side with respect to the antiglare film when the reflectance is obtained. Referring to FIG. 3, the reflected light in the direction of the reflection angle 30 °, that is, the regular reflection direction 305 with respect to the light 303 incident at 30 ° from the normal 302 on the antiglare layer side of the antiglare film 301. Let R (30) be the reflectance (that is, regular reflectance). Of the light 306 reflected at an arbitrary reflection angle θ, the reflectance of reflected light at θ = 40 ° and the reflectance of reflected light at θ = 50 ° are R (40) and R (50), respectively. . The direction of the reflected light when measuring the reflectance (the reflection direction of the light 306 reflected at the regular reflection direction 305 and the reflection angle θ) is within the plane 308 including the direction of the incident light 303 and the normal 302. To do.

  4 shows the reflection angle θ and the reflectance (reflectance) of the light 306 reflected at the reflection angle θ with respect to the light 303 incident at an angle of 30 ° from the normal 302 on the antiglare layer side of the antiglare film 301 in FIG. Is an example of a graph plotting the relationship with logarithmic scale). Such a graph representing the relationship between the reflection angle and the reflectance, or the reflectance for each reflection angle read therefrom may be referred to as a reflection profile. As shown in this graph, the regular reflectance R (30) is a reflectance peak for the light 303 incident at 30 °, and the reflectance tends to decrease as the angle deviates from the regular reflection direction.

  When the regular reflectance R (30) exceeds 0.2%, a sufficient antiglare function cannot be obtained, and the visibility tends to decrease. On the other hand, even if the regular reflectance R (30) is too small, it tends to cause whitishness, so it is preferably 0.04% or more. On the other hand, if R (40) exceeds 0.02%, whitening tends to occur, and if it is less than 0.005%, sufficient antiglare property is not exhibited. R (50) is preferably 0.0015% or less, because if it is too large, whitening tends to occur. From the viewpoint of whitishness, R (50) is preferably as small as possible, but practically the lower limit is about 0.0001%.

  In the antiglare film of the present invention, R (30), R (40) and R (50) are within the above range, and R (35) / R (30) is 0.4 or more and 0.8. The following is more preferable. Here, R (35) is defined in the same manner as described above, and is a reflectance in a direction of a reflection angle of 35 ° with respect to light incident at an incident angle of 30 °. By satisfying these requirements, it is possible to obtain an antiglare film that exhibits a sufficient antiglare property, has a low haze, and is further suppressed in whiteness and glare. Such preferable reflectance characteristics can be obtained by controlling the uneven shape of the metal mold used in the embossing method. The value of R (35) / R (30) corresponds to the inclination near the reflection angle of 30 ° in FIG. 4, that is, the inclination near the regular reflection angle. This is because the reflectance is shown on a logarithmic scale in FIG. When the inclination of the reflection profile near the regular reflection angle is steep, that is, when the value of R (35) / R (30) is less than 0.4, the reflection of the light source is abruptly reflected near the regular reflection angle. As a result, the reflected image is reflected and the antiglare property is lowered. Focusing only on the anti-reflection effect, it is preferable that the inclination in the vicinity of the regular reflection angle is approximately 0, that is, the value of R (35) / R (30) is approximately 1, but R (35). When the value of / R (30) exceeds 0.8, whitening is likely to occur. Accordingly, R (35) / R (30) is preferably 0.8 or less.

  In the example of the reflection profile shown in FIG. 4, the regular reflectance R (30) is about 0.074%, R (40) is about 0.013%, and R (50) is about 0.0004%. . The value of R (35) / R (30) is about 0.6.

  The shape of the reflection profile in the case where the requirements regarding the above four reflectance characteristics, that is, R (30), R (40), R (60), and R (35) / R (30) are satisfied is the regular reflectance. R (30) is low, the inclination near the specular reflection angle is small, and the angle at which the reflectivity is about 1/10 of the specular reflectivity has a spread of about ± 10 ° from the specular reflection direction. The reflectance on the side is kept low. By setting the reflection profile to such a shape, an antiglare film exhibiting excellent antiglare properties while having a low haze is obtained. When the reflection profile does not show such a shape, that is, the inclination near the regular reflection angle is large, and the angle at which the reflectance is about 1/10 of the regular reflectance is about ± 10 ° from the regular reflection direction. When there is no spread, it means that the reflectivity is drastically decreased due to a slight change in angle from the regular reflection direction, and as a result, a reflected image tends to appear.

  Specifically, when an arbitrary light source is reflected with respect to the antiglare film showing the preferable reflection profile, a reflected light amount close to regular reflected light is obtained in the range of the regular reflection angle ± 10 °, and as a result The image of the light source can be sufficiently scattered and blurred. On the other hand, when an arbitrary light source is reflected on an anti-glare film that has a large inclination near the regular reflection angle and does not show a widened reflection profile, the light source is drastically changed by slightly changing the angle from the regular reflection direction. The reflected light from the is reduced. This means that the regular reflection light and the surroundings can be clearly distinguished, that is, the reflected light is imaged and reflected.

  In measuring the reflectance of the antiglare film, it is necessary to accurately measure the reflectance of 0.001% or less. Therefore, it is effective to use a detector with a wide dynamic range. As such a detector, for example, a commercially available optical power meter can be used, and an aperture is provided in front of the detector of this optical power meter so that the angle at which the antiglare film is viewed is 2 °. Measurements can be made using an angular photometer. As incident light, visible light of 380 to 780 nm can be used, and as a measurement light source, a collimated light emitted from a light source such as a halogen lamp may be used, or a monochromatic light source such as a laser is used in parallel. A high degree may be used. In the case of an antiglare film having a smooth and transparent back surface, reflection from the back surface of the antiglare film may affect the measured value. For example, the smooth surface of the antiglare film is adhered to a black acrylic resin plate with an adhesive or It is preferable that only the reflectance on the outermost surface of the antiglare film can be measured by optical adhesion using a liquid such as water or glycerin.

  In view of the above, the reflectances R (30), R (35), R (40) and R (50) defined in the present invention are measured as follows. That is, the uneven surface of the antiglare film is irradiated with parallel light from a He—Ne laser from a direction inclined by 30 ° with respect to the film normal, and the angle in a plane including the film normal and the light incident direction is set. Measure the reflectivity when changed. In the measurement of reflectance, both “3292 03 optical power sensor” and “3292 optical power meter” manufactured by Yokogawa Electric Corporation are used.

Further, the antiglare film of the present invention has the above R (30), R (40) and R (50) within the above range, and the surface unevenness of the antiglare film shown in the following (a) to (f). More preferably, at least one of the requirements regarding the shape is satisfied. By satisfying these requirements, it is possible to obtain an antiglare film that exhibits a sufficient antiglare property, has a low haze, and is further suppressed in whiteness and glare. A preferable uneven surface shape as shown in the following (a) to (f) can be obtained by controlling the uneven shape of the metal mold used in the embossing method.
(A) the arithmetic mean height P _a in an arbitrary cross section curve of the antiglare film uneven surface is not more than 0.21μm than 0.09 .mu.m.
(B) The maximum cross-sectional height P _t in an arbitrary cross-sectional curve on the uneven surface of the antiglare film is 0.5 μm or more and 1.2 μm or less.
(C) average length PS _m in an arbitrary cross section curve of the antiglare film uneven surface is 12μm or more 20μm or less.
(D) When the elevation of each point on the uneven surface of the antiglare film is represented by a histogram, the peak of the histogram is the midpoint (height) between the highest point (height 100%) and the lowest point (height 0%). 50%) and within a range of ± 10%.
(E) It has 150 or more and 350 or less convex parts in the area | region of 200 micrometers x 200 micrometers.
(F) The average area of the polygon formed when the surface of the antiglare film surface irregularities is Voronoi-divided with the apex of the convex part of the surface asperity being 100 μm ² or more and 300 μm ² or less.

First, the above (a) to (c) will be described. The arithmetic average height P _a , the maximum cross-sectional height P _t, and the average length PS _m are defined in JIS B 0601 (same as ISO 4287). Arithmetic average height P _a is also referred to as center line average roughness.

If the arithmetic average height P _a in the cross section curve of the uneven surface is less than 0.09μm, the surface of the antiglare film is almost flat, not show sufficient antiglare performance. Also, arithmetic mean height P _a is the case 0.21μm greater than, the surface shape becomes too rough, problems can arise such as Shirochake and glare. If the maximum section height P _t in a cross section curve of the uneven surface is less than 0.5μm it is also antiglare film surface becomes substantially flat, not show sufficient antiglare performance. Further, when the maximum section height P _t is larger than 1.2μm, also the surface shape becomes too rough, problems can arise such as Shirochake and glare. When the average length PS _m in the cross section curve of the uneven surface is less than 12μm, the surface shape becomes rough, problems can arise such as Shirochake and glare. Further, if the average length PS _m is greater than 20μm, also antiglare film surface becomes substantially flat, not show sufficient antiglare performance.

In the present invention, the arithmetic average height P _a in the cross section curve of the uneven surface, the maximum section height P _t and average length PS _m is measured according to JIS B 0601. Such measurement can be performed using a commercially available general contact type surface roughness meter. In addition, the surface shape can be measured by a device such as a confocal microscope, an interference microscope, or an atomic force microscope (AFM), and can be obtained by calculation from the three-dimensional information of the surface shape. In order to ensure a sufficient reference length, three or more areas of 200 μm × 200 μm or more are measured, and the average value thereof is taken as the measured value.

  Next, the above (d) will be described. This requirement means that the peak of the histogram is in the range of 40% to 60% with respect to the difference between the highest and lowest elevations (maximum elevation). If the peak does not exist within ± 10% from the midpoint, in other words, if the peak appears at a position greater than 60% or less than 40% relative to the maximum elevation, the surface shape becomes rough as a result. , Glare is likely to occur. In addition, the texture of the appearance tends to be reduced.

  In determining the elevation histogram, the surface shape is measured with a confocal microscope, interference microscope, atomic force microscope (AFM), etc., and the three-dimensional coordinate values of each point on the surface of the antiglare film are obtained. It is determined by the algorithm shown below. That is, after obtaining the highest and lowest elevations on the antiglare film surface, the difference between the elevation of the measurement point and the lowest point (the height of that point) is the difference between the highest and lowest points (maximum elevation). ) To obtain the relative height of each point. The peak position of the histogram is obtained by expressing the obtained relative height as a histogram with the highest point being 100% and the lowest point being 0%. The histogram needs to be divided so that the peak position is not affected by the error of the data, and is displayed divided into about 10 to 30. In this measurement, in order to reduce the error, three or more points of an area of 200 μm × 200 μm or more are measured, and the average value is taken as a measured value.

  FIG. 5 shows an example of an elevation histogram. In this figure, the horizontal axis represents the ratio (unit%) of the height of the measurement point to the difference (maximum elevation) between the above-mentioned highest and lowest points, and is divided in increments of 5%. . For example, the leftmost vertical bar indicates the distribution of a set whose height ratio is in the range of 0 to 5%, and the ratio of height increases by 5% as it goes to the right. In this figure, a scale is displayed every three divisions on the horizontal axis. The vertical axis represents the height distribution and is a value that becomes 1 when integrated. In this example, the peak position appears at a position of 45% to 50% with respect to the maximum altitude.

  Next, (e) will be described. When the number of convex portions in the 200 μm × 200 μm region is less than 150, glare due to interference with pixels occurs when used in combination with a high-definition image display device, and the image tends to be difficult to see. is there. Moreover, when the number of convex parts exceeds 350, as a result, the inclination angle of the surface irregularity shape becomes steep, and whitening is likely to occur.

  In determining the number of protrusions on the concavo-convex surface of the antiglare film, the surface shape is measured with an apparatus such as a confocal microscope, an interference microscope, an atomic force microscope (AFM), etc. After obtaining a coordinate value, a convex portion is determined by the following algorithm, and the number of the convex portions is counted. That is, when an arbitrary point on the surface of the antiglare film is focused on, there is no point higher than the focused point around that point, and the altitude on the uneven surface of that point is the highest of the uneven surface. When the altitude of the point is higher than the middle of the lowest point, the point is assumed to be the vertex of the convex portion, and the number of convex vertices thus obtained is counted to obtain the number of convex portions. More specifically, as shown in FIG. 6, paying attention to an arbitrary point 601 on the surface of the antiglare film, a circle having a radius of 2 μm to 5 μm parallel to the reference surface 603 of the antiglare film is drawn around the point 601. The point on the antiglare film surface 602 included in the plane of the projected circle 604 of the circle does not have a point that is higher than the point of interest 601 and is on the uneven surface of the point. When the altitude is higher than the midpoint between the highest altitude and the lowest altitude of the uneven surface, it is determined that the point 601 is the apex of the convex portion, and the number of convex portions is obtained. At this time, the radius of the projected circle 604 is required to be a size that does not count fine irregularities on the sample surface and does not include a plurality of convex portions, and is preferably about 3 μm. In the measurement, in order to reduce the error, three or more points of a 200 μm × 200 μm region are measured, and the average value is used as a measured value.

  When measurement is performed using a confocal microscope, the magnification of the objective lens is about 50 times, and the measurement is performed with reduced resolution. This is because if the measurement is performed at a high resolution, fine irregularities on the surface of the sample are measured, and the counting of the convex portions is hindered. Note that when the objective lens is set to a low magnification, the resolution in the height direction is also reduced, so that the surface shape may be difficult to measure in the case of a sample with few irregularities. In such a case, after measuring with a high-magnification objective lens, a low-pass filter is applied to the obtained data to remove high spatial frequency components so that the fine roughness observed on the uneven surface cannot be seen. After that, the number of convex parts is counted.

  Next, the above (f) will be described. First, the Voronoi division will be explained. When several points (called mother points) are arranged on a plane, the plane can be divided depending on which mother point is closest to any point in the plane. The figure is called Voronoi diagram, and the division is called Voronoi division. FIG. 7 shows an example in which the surface of the surface of the antiglare film is Voronoi divided with the apex of the convex portion as a base point. As shown in FIG. 7, a Voronoi polygon 702 (sometimes called a Voronoi region) including the mother point is assigned to each of a large number of mother points 701 by Voronoi division. In the Voronoi diagram, the number of generating points coincides with the number of Voronoi regions.

When the average area of Voronoi polygons formed when Voronoi is divided using the top of the convex part as the base point is less than 100 μm ² , the inclination angle of the antiglare film surface becomes steep, resulting in whitening. It becomes easy to do. On the other hand, when the average area of the Voronoi polygon is larger than 300 μm ² , the uneven surface shape becomes rough and glare is likely to occur.

  Equipment such as confocal microscope, interference microscope, and atomic force microscope (AFM) is used to determine the average area of Voronoi polygons obtained by performing Voronoi division using the top of the convex part of the antiglare film as a generating point. After measuring the surface shape and obtaining the three-dimensional coordinate value of each point on the surface of the antiglare film, the Voronoi division is performed by the following algorithm to obtain the average area of the Voronoi polygon. That is, according to the algorithm described above with reference to FIG. 6, first, the vertex of the convex portion on the surface of the antiglare film is obtained, and then the vertex of the convex portion is projected onto the reference surface of the antiglare film. After that, all the three-dimensional coordinates obtained by measuring the surface shape are projected onto the reference plane, and all the projected points are assigned to the nearest generating points to perform Voronoi division and obtained by division. By determining the area of the polygon, the average area of the Voronoi polygon is determined. In the measurement, in order to reduce the error, the Voronoi polygon 703 that is in contact with the boundary of the measurement visual field is not included in calculating the average area. In order to reduce the measurement error, three or more areas of 200 μm × 200 μm or more are measured, and the average value is taken as the measured value.

In addition, the anti-glare film of this invention may have the low reflection film 801 in the outermost surface, ie, the uneven | corrugated surface side of an anti-glare layer, as FIG. 8 shows. Even in the absence of a low reflection film, a sufficient antiglare function is exhibited, but the antiglare property can be further improved by providing a low reflection film on the outermost surface. The low reflection film can be formed by providing a layer of a low refractive index material having a lower refractive index on the antiglare layer. Specific examples of such a low refractive index material include lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), aluminum fluoride (AlF ₃ ), cryolite (3NaF · AlF ₃ or Na ₃ AlF _6). ) And other inorganic low-reflective materials containing acrylic resin, epoxy resin, etc .; fluorine-based or silicone-based organic compounds, thermoplastic resins, thermosetting resins, UV-curable resins, etc. An organic low reflection material can be mentioned.

  The antiglare film of the present invention is excellent in the antiglare effect and effectively prevents whiteness and glare, so that it has excellent visibility when mounted on an image display device. When the image display device is a liquid crystal display, this antiglare film can be applied to the polarizing plate. In other words, in general, there are many polarizing plates in which a protective film is bonded to at least one surface of a polarizing film made of a polyvinyl alcohol-based resin film adsorbed and oriented with iodine or a dichroic dye. The antiglare film of the present invention is used. By attaching the polarizing film and the antiglare film of the present invention on the resin base film side of the antiglare film, an antiglare polarizing plate can be obtained. In this case, the other surface of the polarizing film may be in a state where nothing is laminated, another protective film or an optical film may be laminated, and an adhesive layer for bonding to a liquid crystal cell. May be formed. In addition, the antiglare film of the present invention is bonded on the side of the resin substrate film on the protective film of the polarizing plate having a protective film bonded to at least one surface of the polarizing film to obtain an antiglare polarizing plate. You can also Furthermore, in the polarizing plate having a protective film bonded to at least one side, after bonding the resin base film to the polarizing film as the protective film, by forming the antiglare layer on the resin base film, It can also be set as an anti-glare polarizing plate.

  An image display device can be obtained by combining the antiglare film or the antiglare polarizing plate of the present invention with an image display element. Here, the image display element is typically a liquid crystal panel that includes a liquid crystal cell in which liquid crystal is sealed between upper and lower substrates and displays an image by changing the alignment state of the liquid crystal by applying a voltage. The antiglare film or the antiglare polarizing plate of the present invention can also be applied to various known displays such as a display panel, a CRT display, and an organic EL display. In the image display device of the present invention, the antiglare film is disposed on the viewing side with respect to the image display element. Under the present circumstances, it arrange | positions so that the uneven surface of an anti-glare film, ie, the glare-proof layer side, may become an outer side (viewing side). The antiglare film may be directly bonded to the surface of the image display element. When the liquid crystal panel is used as the image display means, for example, as described above, the antiglare film is bonded to the surface of the liquid crystal panel via the polarizing film. You can also Thus, the image display device provided with the antiglare film of the present invention can scatter incident light due to the unevenness of the surface of the antiglare film and blur the reflected image, giving excellent visibility. Further, even when the antiglare film of the present invention is applied to a high-definition image display device, whitishness and glare are effectively prevented and excellent antiglare properties are exhibited.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. The evaluation method of the antiglare film performed in common in the following examples and comparative examples is as follows.

(1) Measurement of haze of antiglare film In order to prevent warping, an antiglare film is bonded to a glass substrate using an optically transparent pressure-sensitive adhesive so that the uneven surface becomes the surface. It used for the measurement. As a measuring device, a haze meter “HM-150” manufactured by Murakami Color Research Laboratory Co., Ltd. based on JIS K 7136 was used.

(2) Evaluation of glare The glare was evaluated by the following method. That is, first, a photomask having a unit cell pattern shown in FIG. 9 was produced. In this figure, the unit cell 900 has a key-shaped chrome light shielding pattern 901 with a line width of 10 μm formed on a transparent substrate, and a portion where the chrome light shielding pattern 901 is not formed is an opening 902. Here, a unit cell having a size of 254 μm × 84 μm (vertical × horizontal in the figure), and therefore, an opening 902 having a size of 244 μm × 74 μm (vertical × horizontal in the figure) was used. A large number of unit cells shown in the figure are arranged vertically and horizontally to form a photomask.

  Then, as shown in FIG. 10, the photomask 903 is placed in the light box 905 with the chrome light shielding pattern 901 facing up, and the antiglare film 1001 is bonded to the glass plate 907 with an adhesive so that the uneven surface is the surface. The obtained sample is placed on a photomask 903. A light source 906 is disposed in the light box 905. In this state, by visually observing at a position 909 that is about 30 cm away from the sample, the degree of glare was sensory evaluated in seven stages. Level 1 is a state in which no glare is recognized, level 3 is a state in which a slight glare is observed, and level 7 is a state in which intense glare is observed. Glare is recognized when anti-glare film of level 1 to 3 is placed on the outermost surface of a 26-52 inch large TV display of full high-definition data format, mobile phones of XVGA and VGA display formats, car navigation systems, etc. I can't.

<Example 1>
(A) Production of Embossing Mold The surface of an aluminum roll having a diameter of 300 mm (A5056 according to JIS) was mirror-polished. To the outer surface of the obtained mirror-polished aluminum roll, using a blasting device (obtained from Fuji Seisakusho Co., Ltd.), zirconia beads “TZ-SX-17” (trade name, average particle diameter) manufactured by Tosoh Corporation 20 μm) was blasted at a blast pressure of 0.1 MPa (gauge pressure, the same applies hereinafter), and the surface was made uneven. The uneven surface of the resulting uneven aluminum roll was subjected to electroless bright nickel plating to produce a metal mold. The plating thickness was set to 15 μm, and after plating, the plating thickness was measured using a β-ray film thickness measuring device (trade name “Fischer Scope MMS”, obtained from Fisher Instruments Co., Ltd.) and found to be 17.2 μm. It was.

(B) Production of anti-glare film Photo-curable resin composition “GRANDIC PC1141” manufactured by Dainippon Ink and Chemicals, Inc. (trade name, refractive index after curing: 1.514, photopolymerization initiator is blended. ) Is dissolved in ethyl acetate to obtain a solution having a resin component concentration of 45% by weight, and non-spherical light diffusing particles A (aspect ratio L _max / L _ver 1.6, average particle size) made of acrylic resin. A coating solution was prepared by adding 15 parts by weight of a particle (converted into a volume equivalent sphere diameter) of 6 μm and a refractive index of 1.49 per 100 parts by weight of the resin component in the solution.

This coating solution was applied onto an 80 μm thick triacetylcellulose (TAC) film (resin base film) so that the coating thickness after drying was 21 μm, and dried for 3 minutes in a dryer set at 60 ° C. I let you. The dried film was adhered to the concavo-convex surface of the metal mold prepared above with a rubber roll so that the photocurable resin layer was on the nickel plating layer side. In this state, the photocurable resin layer was cured by irradiating light from an electrodeless mercury lamp with an intensity of 20 mW / cm ² from the TAC film side so that the amount of light in terms of h-line was 300 mJ / cm ² . Then, the TAC film was peeled from the mold together with the cured product layer, and a transparent antiglare film composed of a laminate of a cured product (antiglare layer) having irregularities on the surface and the TAC film was produced. The optical characteristics of the antiglare film were evaluated by the above method.

  Table 1 shows the properties of the non-spherical light diffusing particles used, the thickness of the antiglare layer, and the optical characteristics of the antiglare film.

<Examples 2 to 4>
As non-spherical light diffusing particles, light diffusing particles B to D each made of an acrylic resin were used, and the addition amount and the thickness of the antiglare layer were changed as shown in Table 1 in the same manner as in Example 1. Thus, an antiglare film was produced. Table 1 shows the optical characteristics of the obtained antiglare film. In addition, all the non-spherical particles made of the acrylic resin used in Examples 1 to 4 were obtained from Sekisui Chemical Co., Ltd., and the shape thereof was a meteorite shape (biconvex lens shape).

<Comparative Examples 1-9>
As the light diffusing particles, the following spherical particles were used, and an antiglare film was produced in the same manner as in Example 1 except that the addition amount and the thickness of the antiglare layer were changed as shown in Table 1. Table 1 shows the optical characteristics of the obtained antiglare film.
(1) Comparative Example 1: Light diffusing particles MX-500 [acrylic resin spherical particles, average particle size 5 μm, manufactured by Soken Chemical]
(2) Comparative Example 2: Light diffusing particles SX-500 [polystyrene spherical particles, average particle size 5 μm, manufactured by Soken Chemical]
(3) Comparative Example 3: Light diffusing particles SX-713L [polystyrene spherical particles, average particle size 7.2 μm, manufactured by Soken Chemical]
(4) Comparative Example 4: Light diffusing particles KE-P-250 [amorphous silica, average particle size 2.5 μm, manufactured by Nippon Shokubai]
(5) Comparative Example 5: Light diffusing particles KE-P-150 [amorphous silica, average particle size 1.5 μm, manufactured by Nippon Shokubai]
(6) Comparative Example 6: Light diffusing particle Tospearl 130 [silicone particles, average particle size 3 μm, manufactured by Toshiba Silicone]
(7) Comparative Example 7: Light diffusing particles XX-104K [Methyl methacrylate-styrene copolymer spherical particles, average particle size 7.5 μm, manufactured by Sekisui Plastics Co., Ltd.]
(8) Comparative Example 8: Light diffusing particles XX-111K [Methyl methacrylate-styrene copolymer spherical particles, average particle size of 5 μm, manufactured by Sekisui Plastics Co., Ltd.]
(9) Comparative Example 9: Light diffusing particles SFP-30M [silica spherical particles, average particle size 0.5 μm, manufactured by Denki Kagaku Kogyo]

  In Table 1, for example, when Example 1 is compared with Comparative Example 1, for example, light diffusing particles having an aspect ratio exceeding 1 are used although the properties and haze values other than the aspect ratio of the light diffusing particles are almost equal. In Example 1, the glare was slightly felt, and in Comparative Example 1 using true spherical light diffusing particles, glare was clearly felt. Also in Examples 2-4, compared with Comparative Examples 1-9, it became a result that it was hard to feel glare with respect to a haze value.

<Example 5>
An ultraviolet curable resin composition (refractive index after curing 1.53) in which the following components were dissolved in ethyl acetate at a solid content concentration of 60% was prepared.

Pentaerythritol triacrylate 60 parts Multifunctional urethanated acrylate 40 parts (Reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate)
Next, with respect to 100 parts by weight of the resin component of the ultraviolet curable resin composition, “Lucirin TPO” (made by BASF, chemical name: 2,4,6-trimethylbenzoyldiphenyl) is used as a photopolymerization initiator. 5 parts by weight of phosphine oxide) and 15 parts by weight of the light diffusing particles A used in Example 1 were added to prepare a coating solution.

  This coating solution was applied onto a 80 μm thick triacetylcellulose (TAC) film (resin base film) so that the coating thickness after drying was 11.4 μm. Thereafter, the same procedure as in Example 1 was performed. An antiglare film was produced. The optical characteristics of the antiglare film were evaluated by the above method. Table 2 shows the properties of the non-spherical light diffusing particles used, the thickness of the antiglare layer, and the optical characteristics of the antiglare film. In addition, in order to evaluate the contrast, the antiglare is applied to a polarizing plate (trade name “Sumikaran SRDB31E”, manufactured by Sumitomo Chemical Co., Ltd.) in which a transparent protective film is attached to both surfaces of a polyvinyl alcohol-iodine linear polarizing film. The film was stuck on the resin base film side through an adhesive to produce an antiglare polarizing plate.

<Example 6>
An antiglare film was prepared in the same manner as in Example 5 except that the addition amount of the light diffusing particles was changed as shown in Table 2, and the antiglare polarizer was further adhered to the polarizing plate. Produced. Table 2 shows the optical properties of the obtained antiglare film.

  Moreover, using each anti-glare polarizing plate obtained in Examples 5 and 6, a liquid crystal display device was produced as follows, and the contrast was evaluated. The results are also shown in Table 2.

(Contrast evaluation)
First, the polarizing plate on the back side and the display surface side is peeled off from a commercially available liquid crystal television (“LC-32GS10” manufactured by Sharp Corporation). The produced anti-glare polarizing plate has the anti-glare film side as the surface (opposite side of the liquid crystal cell), and on the back side, a polarizing plate “Sumikaran SRDB31E” manufactured by Sumitomo Chemical Co., Ltd. Was bonded via an adhesive so that the absorption axis of the film coincided with the absorption axis of the original polarizing plate. Next, the liquid crystal television thus obtained was activated in a dark room, and using a luminance meter “BM5A” manufactured by Topcon Corporation, the luminance in the black display state and the white display state was measured, and the contrast was calculated. Here, the contrast is represented by the ratio of the luminance in the white display state to the luminance in the black display state.

<Comparative Examples 10 and 11>
As the light diffusing particles, the anti-glare film was prepared in the same manner as in Example 5 except that the light diffusing particles MX-500 used in Comparative Example 1 were used and the addition amount was as shown in Table 2. Further, it was attached to a polarizing plate to produce an antiglare polarizing plate. Table 2 shows the evaluation results of the obtained antiglare film and antiglare polarizing plate.

  It was found that the contrast of the liquid crystal display devices using the antiglare films of Examples 5 and 6 was equal to or higher than that of Comparative Examples 10 and 11.

<Comparative Example 12 and Comparative Example 13>
The coating solutions used in Examples 5 and 6 were each coated on a triacetyl cellulose (TAC) film (resin base film) having a thickness of 80 μm and dried in a dryer set at 60 ° C. for 3 minutes. Without bringing the dried film into close contact with the metal mold (that is, with the coated surface being opened), light from an electrodeless mercury lamp with an intensity of 20 mW / cm ² from the coated surface side is 300 mJ / light in terms of h-line conversion. The photocurable resin layer was cured by irradiation so as to be cm ² . Thus, a transparent antiglare film comprising a laminate of a cured product (antiglare layer) having irregularities on the surface and a TAC film was produced. Table 3 shows the optical properties of the obtained antiglare film. In addition, what was produced from the coating liquid used in Example 5 is Comparative Example 12, and what was produced from the coating liquid used in Example 6 is Comparative Example 13.

  In the antiglare films of Examples 1 to 6 and Comparative Examples 1 to 11 produced by transferring the surface unevenness shape of the metal mold, whitishness was not observed, but Comparative Example 12 in which the embossing method was not used. In and 13, a clear whitish was observed. In Comparative Examples 12 and 13, since an appropriate surface shape by embossing is not formed, the light diffusing particles cannot be completely embedded in the antiglare layer, and the particles protrude from the surface of the antiglare layer. There was also a glare caused by.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The anti-glare film of the present invention is more visible than the image display element for various displays such as liquid crystal panels, plasma display panels, cathode ray tube (CRT) displays, organic EL displays, and SEDs. By arranging in this manner, it is possible to blur the reflected image without generating whiteness and glare, and to provide excellent visibility.

It is a cross-sectional schematic diagram which shows a preferable example of the anti-glare film of this invention. It is the schematic which shows an example of the shape of the non-spherical light diffusable particle used for this invention. It is a perspective view which shows typically the incident direction and reflection direction of the light from the glare-proof layer side when calculating | requiring a reflectance. It is an example of the graph which plotted the relationship between the reflection angle and the reflectance (a reflectance is a logarithmic scale) of the reflected light with respect to the light which injected at an angle of 30 degrees from the normal line of an anti-glare film. It is an example which represented the altitude histogram of the anti-glare film on the graph. It is a perspective view which shows typically the algorithm of the convex part determination of an anti-glare film. It is a Voronoi figure which shows an example when performing Voronoi division | segmentation by using the convex-part vertex of an anti-glare film as a base point. It is a cross-sectional schematic diagram which shows another preferable example of the anti-glare film of this invention. It is a top view which shows the unit cell of the pattern for glare evaluation. It is a cross-sectional schematic diagram which shows the state of glare evaluation.

Explanation of symbols

  101 resin base film, 102 antiglare layer, 103 light diffusing particles, 104 transparent resin, 301,1001 antiglare film, 302 normal line of antiglare film, 303 light incident at an angle of 30 °, 305 regular reflection Direction, 306 light reflected at a reflection angle θ, 308 plane including incident light direction and normal line of antiglare film, 601 arbitrary point on antiglare film, 602 antiglare film surface, 603 antiglare film reference surface, 604 Projection circle of anti-glare film centered on any point on anti-glare film on anti-glare film reference plane, 701 Voronoi division mother point (projection point of convex vertex), 702 Voronoi polygon, 703 Measurement boundary Voronoi polygon in contact, 801 low reflection film, 900 photomask unit cell, 901 photomask chrome shading pattern, 902 photomask opening Mouth, 903 Photomask, 905 Light box, 906 Light source, 907 Glass plate, 909 Glare observation position.

Claims (11)

An anti-glare film comprising a resin base film and an anti-glare layer laminated on the surface of the resin base film and having an uneven shape on the surface,
The antiglare layer is a layer made of a transparent resin in which non-spherical light diffusing particles having an aspect ratio of more than 1 represented by the following formula (1) are dispersed,
The uneven shape of the surface of the antiglare layer is an antiglare film formed by an embossing method using a metal mold.
Aspect ratio = L _max / L _ver (1)
Here, L _max is the maximum length of the projection surface when the projection area of the light diffusing particles is minimized, and L _ver is a direction orthogonal to the L _max direction on the projection surface. The maximum length.   2. The antiglare film according to claim 1, wherein the uneven shape of the antiglare layer surface is a surface uneven shape mainly formed by the transparent resin.   The antiglare film according to claim 2, wherein the light diffusing particles are buried in an antiglare layer.   The antiglare film according to any one of claims 1 to 3, wherein an aspect ratio of the light diffusing particles is in a range of 1.2 to 2.   The antiglare film according to any one of claims 1 to 4, wherein the light diffusing particles have a meteorite shape or a convex lens shape.   The anti-glare film according to any one of claims 1 to 5, wherein the light diffusing particles are made of an organic resin and are contained within a range of 10 to 35 parts by weight with respect to 100 parts by weight of the transparent resin.   The antiglare film according to any one of claims 1 to 6, wherein the transparent resin is a photocurable resin or a thermoplastic resin.   The antiglare film according to any one of claims 1 to 7, wherein a difference in refractive index between the transparent resin and the light diffusing particles is in a range of 0.02 to 0.5.   The antiglare film according to any one of claims 1 to 8, wherein the haze is in the range of 2 to 40%.   The anti-glare film according to any one of claims 1 to 9, further comprising a low-reflection film on the uneven surface of the anti-glare layer. It comprises at least the antiglare film according to any one of claims 1 to 10 and an image display element,
The antiglare film is an image display device disposed on the viewing side of the image display element.

Images