TWI499809B - Antiglare filim and liquid crystal display device - Google Patents

Description

Anti-glare film and liquid crystal display device

The present invention relates to an anti-glare film excellent in anti-glare property and a liquid crystal display device having the anti-glare film.

[Anti-glare film]

For an image display device such as a liquid crystal display and a plasma display panel, a Braun tube (CRT) display, or an organic electroluminescence (EL) display, visual recognition is performed when external light is reflected on the display surface thereof. Sex will be significantly impaired. In order to prevent the reflection of such external light, in the TVs and personal computers that emphasize image quality, cameras and digital cameras used outside the house where external light is strong, and mobile phones that use reflected light for display, etc., An anti-glare film is used on the surface of the display device to prevent external light from being reflected.

As such an anti-glare film, for example, JP-A-2006-53371 discloses an anti-glare film which is produced by electroless plating after polishing a substrate and performing sandblasting. Nickel is produced by a roll having fine unevenness on its surface, and is cured while pressing the uneven surface of the roll against the photocurable resin layer formed on the TAC film.

[Liquid Crystal Display Device]

The liquid crystal display device is characterized by its advantages such as light weight, thinness, and low power consumption, and its use in televisions, personal computers, portable terminals, and the like is progressing. In the liquid crystal display device used for the purpose of displaying a video on a television or the like, the visibility is particularly important in the contrast ratio when viewed from the front and the contrast ratio when viewed from the oblique direction.

In addition, the visibility of the liquid crystal display device is significantly impaired when external light is reflected on the display surface thereof. In order to prevent this kind of external light from entering, it is always in the image of TVs and personal computers that pay attention to image quality, cameras and digital cameras that are used outside the house, and mobile phones that use reflected light for display. An anti-glare film is used on the surface of the display device to prevent external light from being reflected.

In addition to the anti-glare property, the anti-glare film is required to exhibit a good contrast when disposed on the surface of the image display device, and suppress the so-called "whitening" when disposed on the surface of the liquid crystal display device. "Occurrence occurs; and when the surface of the liquid crystal display device is disposed on the surface of the liquid crystal display device, the occurrence of a so-called "glittering" phenomenon is suppressed. Here, the "fading" causes the entire display surface to become white due to the scattered light, and the display becomes unclear. The above-mentioned "flashing" causes interference between the pixels of the liquid crystal display device and the surface unevenness of the anti-glare film, and as a result, a brightness distribution cloth is generated and it is difficult to view.

[Problem of the first invention]

In addition to the anti-glare property, the anti-glare film is required to exhibit good contrast when disposed on the surface of the image display device, and suppress the occurrence of so-called "fading" when disposed on the surface of the liquid crystal display device. When the surface of the liquid crystal display device is disposed on the surface of the liquid crystal display device, the occurrence of a so-called "flashing" phenomenon is suppressed. The above-mentioned "fading" means that the entire display surface is whitened by the scattered light, and the display becomes unclear; the above-mentioned "flashing" refers to liquid crystal. The pixel of the display device and the surface uneven shape of the anti-glare film interfere with each other, and as a result, a luminance distribution occurs, which is difficult to view. However, since the anti-glare film described in Patent Document 1 is produced by using a mold having a concavo-convex shape by sandblasting, it is insufficient in the accuracy of the concavo-convex shape, and in particular, it may have a period of 50 μm or more. The relatively large concave and convex shape is therefore prone to "flashing".

[Second Problem of the Invention]

A liquid crystal display device having improved contrast ratio, viewing angle characteristics, and anti-glare property is disclosed in Japanese Laid-Open Patent Publication No. Hei. No. 2006-039270 and Japanese Patent Laid-Open Publication No. Hei No. 2007-256766. A liquid crystal display device of a board, wherein the polarizing plate has a predetermined retardation film and an anti-glare film. More specifically, Japanese Laid-Open Patent Publication No. 2006-039270 discloses a liquid crystal display device by a liquid crystal cell, a linear polarizer, a uniaxial or biaxial property in a vertical alignment mode. The phase difference plate and the completely biaxial phase difference plate are applied together to an anti-glare layer which is divided into a predetermined domain area, and the visual recognition property is improved. In addition, Japanese Laid-Open Patent Publication No. 2007-256766 discloses a liquid crystal display device in which a linear polarizer is disposed above and below a liquid crystal cell in a vertical alignment mode, and between either a cell substrate and a linear polarizer. A positively uniaxial or biaxial phase difference plate is disposed, and a completely biaxial phase difference plate is disposed between the phase difference plate and the case substrate or between another case substrate and the linear polarizer, and in addition, The surface side, that is, the identification side, is provided with an anti-glare layer that imparts specific optical characteristics and has a specific surface shape, whereby the visibility is improved.

However, the anti-glare film described in JP-A-2006-256766 and JP-A-2007-256766 are produced by using an embossing die having a concave-convex shape by sandblasting, so that the accuracy of the uneven shape is insufficient. However, there is a case in which a relatively large uneven shape having a period of 50 μm or more is present, and thus there is a problem that "flashing" is liable to occur.

[Third Problem of the Invention]

As a liquid crystal display device having improved contrast ratio, viewing angle characteristics, and anti-glare property, Japanese Laid-Open Patent Publication No. Hei. No. 2006-053511 and Japanese Patent Laid-Open No. Hei. No. 2007-256765 disclose that a twisted nematic liquid crystal display device is disposed. A liquid crystal display device of a polarizing plate, wherein the polarizing plate has a predetermined optical anisotropic layer and an anti-glare film. More specifically, Japanese Laid-Open Patent Publication No. 2006-053511 discloses a liquid crystal display device in which a liquid crystal cell and a linear polarizer are formed by sandwiching a twisted nematic liquid crystal between two electrode substrates. An optically anisotropic layer which is optically negative or positive uniaxial and whose optical axis is inclined from the normal direction of the film by 5 to 50° is applied to an anti-glare layer which is divided into a predetermined domain area, and visually recognizable. Got an improvement. Further, Japanese Laid-Open Patent Publication No. 2007-256765 discloses a liquid crystal display device in which a liquid crystal cell, a linear polarizer, and an optical body are formed by sandwiching a twisted nematic liquid crystal between two electrode substrates. An optically anisotropic layer having a negative or positive uniaxiality and having an optical axis inclined from the normal direction of the film by 5 to 50° is disposed together with an anti-glare layer imparting specific optical characteristics and having a specific surface shape, and visually recognizing Sex has been improved.

However, since the anti-glare film described in Japanese Laid-Open Patent Publication No. Hei. No. 2007-256765 and the embossing film formed by the blasting process have been formed by blasting, the accuracy of the uneven shape is insufficient. However, there is a case in which a relatively large uneven shape having a period of 50 μm or more is present, and thus there is a problem that "flashing" is liable to occur.

[Fourth Problem of the Invention]

A liquid crystal display device in which a polarizing plate is disposed in a liquid crystal display device of a planar switch (IPS) mode is disclosed in Japanese Laid-Open Patent Publication No. 2008-209861, which is a liquid crystal display device having a contrast ratio, a viewing angle characteristic, and an anti-glare property. The polarizing plate has a predetermined retardation film and an anti-glare film. More specifically, Japanese Laid-Open Patent Publication No. 2008-209861 discloses a liquid crystal display device in which a polarizing plate is disposed above and below the liquid crystal cell of the IPS mode, and at least one phase is disposed between the back side polarizing plate and the cassette substrate. In the difference plate, the phase difference value of the birefringent layer existing between the liquid crystal cell side surface of the polarizer constituting the back side polarizing plate and the back surface side substrate surface of the liquid crystal cell is set to a predetermined range, and the front side is formed. The thickness direction phase difference between the liquid crystal cell side surface of the polarizer of the side polarizing plate and the front side substrate surface of the liquid crystal cell is close to zero, and the identification side is disposed on the display side, that is, the identification side is given a specific optical characteristic and has a specific The anti-glare layer of the surface shape is further improved by contrast and the like.

However, since the anti-glare film described in Japanese Laid-Open Patent Publication No. 2008-209861 is produced by using an embossing die having a concavo-convex shape by sandblasting, the accuracy of the concavo-convex shape is insufficient, and in particular, it may have a holding thickness of 50 μm or more. The cycle has a relatively large concave-convex shape, so there is a problem that "sparkle" is liable to occur.

It is an object of the first invention to provide an anti-glare film which exhibits excellent anti-glare properties and exhibits good contrast and prevents deterioration of visual recognition caused by occurrence of "fading" and "flashing".

[First invention]

According to a first aspect of the invention, there is provided an anti-glare film comprising a transparent support and an anti-glare layer, wherein the anti-glare layer is formed on the transparent support and has a fine uneven surface having fine irregularities on a side opposite to the transparent support, The internal haze is 1% or less, and the surface haze is 0.4% or more and 10% or less, and is incident from the main normal direction of the average surface of the fine uneven surface, and includes the highest level from the fine uneven surface. a plane wave having a wavelength of 550 nm which is an imaginary plane parallel to the average surface of the fine uneven surface, that is, a maximum elevation plane, and a complex amplitude of the highest elevation surface from the elevation of the fine uneven surface and an anti-glare layer The refractive index is calculated, and the one-dimensional power spectrum of the complex amplitude is expressed as the intensity of the spatial frequency, and has a spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less. Two inflection points.

In one aspect of the anti-glare film of the first aspect of the invention, it is preferred that the second-order derivative of the spatial frequency-dependent one-dimensional power spectrum of the complex amplitude is at a spatial frequency of 0.024 μm ^-1 . positive.

In one aspect of the anti-glare film of the first aspect of the invention, the ratio of the micro-faces having an inclination angle of 5 or more in the fine uneven surface is less than 10%.

The anti-glare film of the first invention exhibits excellent anti-glare properties and exhibits good contrast, preventing deterioration of visual recognition caused by occurrence of "fading" and "flashing".

A second object of the present invention is to provide a liquid crystal display device which exhibits excellent anti-glare properties and exhibits good contrast and wide viewing angle characteristics without occurrence of "fading" and "flashing". The resulting visual recognition decline.

[Second invention]

A second aspect of the invention provides a liquid crystal display device including: a liquid crystal cell in which liquid crystal is sealed between a pair of mutually parallel card substrates, the liquid crystal being in a state of no voltage application in the vicinity of the cell substrate relative to the cell substrate Oriented in a substantially vertical direction; a front side polarizing film disposed on an identification side of the liquid crystal cell; a rear side polarizing film disposed on an opposite side thereof; and at least one retardation film disposed on the back side polarizing film and the liquid crystal Between the boxes and/or between the front side polarizing film and the liquid crystal cell; the anti-glare film comprising a transparent support and an anti-glare layer, wherein the anti-glare layer is formed on the transparent support and provided on the transparent support The anti-glare film has a fine uneven surface having fine irregularities on the opposite side of the body, and the anti-glare film is disposed on the opposite side of the surface of the front-side polarizing film facing the liquid crystal cell so that the anti-glare layer is the most recognizable side. The internal haze of the antiglare film is 1% or less, the surface haze is 0.4% or more and 10% or less, and the average surface from the fine uneven surface is a plane wave having a wavelength of 550 nm emitted from a virtual plane having the highest elevation point and having a point of highest elevation parallel to the average plane of the fine uneven surface, and having a wavelength of 550 nm, the complex amplitude of the highest elevation surface The elevation of the surface of the fine concavo-convex surface and the refractive index of the anti-glare layer are calculated; the one-dimensional power spectrum of the complex amplitude is expressed as the intensity of the spatial frequency, and the spatial frequency is 0.032 μm ^-1 or more and 0.064 μm. Within the range of ^-1 or less, there are two inflection points.

In one aspect of the liquid crystal display device of the second aspect of the invention, it is preferable that the in-plane retardation value R ₀ of the retardation film is 50 nm or more and 80 nm or less, and the retardation phase difference R _th of the retardation film is 120 nm. Above 250nm.

In one aspect of the liquid crystal display device of the second aspect of the invention, it is preferable that the second-order derivative function related to the spatial frequency of the one-dimensional power spectrum of the complex amplitude is positive at a spatial frequency of 0.024 μm ^-1 .

In one aspect of the liquid crystal display device of the second aspect of the invention, it is preferable that the ratio of the micro-faces having an inclination angle of 5 or more in the fine uneven surface is less than 10%.

The liquid crystal display device of the second aspect of the invention exhibits excellent anti-glare properties, exhibits good contrast and wide viewing angle characteristics, and prevents deterioration in visual recognition caused by occurrence of "fading" and "flashing".

A third object of the present invention is to provide a liquid crystal display device which exhibits excellent anti-glare properties and exhibits good contrast and wide viewing angle characteristics without occurrence of "fading" and "flashing". The resulting visual recognition decline.

[Third invention]

According to a third aspect of the invention, a liquid crystal display device includes: a liquid crystal cell in which a twisted nematic type liquid crystal is sealed between a pair of mutually parallel cassette substrates; and a front side polarizing film is disposed in the liquid crystal cell An identification side of the liquid crystal cell; a back side polarizing film disposed on the opposite side; and an optical anisotropic layer disposed between the back side polarizing film and the liquid crystal cell and the front side polarizing film And an anti-glare film comprising: a transparent support and an anti-glare layer, wherein the anti-glare layer is formed on the transparent support and has a side opposite to the transparent support The anti-glare film is disposed on the side opposite to the surface of the front-side polarizing film facing the liquid crystal cell so that the anti-glare layer is positioned closest to the side of the anti-glare layer, and the anti-glare film is characterized in that the anti-glare film The internal haze of the glare film is 1% or less, the surface haze is 0.4% or more and 10% or less, and the main normal direction of the average surface from the fine uneven surface is a plane wave having a wavelength of 550 nm which is incident on the surface of the fine uneven surface and having a point having the highest elevation and which is parallel to the average surface of the fine uneven surface, that is, the highest elevation surface, and the complex amplitude of the highest elevation surface is from the fine unevenness The elevation of the surface and the refractive index of the anti-glare layer are calculated; the one-dimensional power spectrum of the complex amplitude is expressed as the intensity of the spatial frequency, and the spatial frequency is 0.032 μm ^-1 or more and 0.064 μm ^-1 or less. Within the range, there are two inflection points.

In one aspect of the liquid crystal display device of the third aspect of the invention, it is preferable that the optical anisotropic layer is disposed between the back side polarizing film and the liquid crystal cell and between the front side polarizing film and the liquid crystal cell.

In one aspect of the liquid crystal display device of the third aspect of the invention, it is preferable that the optically anisotropic layer is optically negative or positive uniaxial, and the optical axis thereof is inclined from the normal direction of the film by 5 Layer to 50°.

In one aspect of the liquid crystal display device of the third aspect of the invention, it is preferable that the second-order derivative function relating to the spatial frequency of the one-dimensional power spectrum of the complex amplitude is positive at a spatial frequency of 0.024 μm ^-1 .

In one aspect of the liquid crystal display device of the third aspect of the invention, it is preferable that the ratio of the micro-faces having an inclination angle of 5 or more in the fine uneven surface is less than 10%.

The liquid crystal display device of the third invention exhibits excellent anti-glare properties, exhibits good contrast and wide viewing angle characteristics, and prevents visual recognition degradation caused by occurrence of "fading" and "flashing".

A fourth object of the present invention is to provide a liquid crystal display device which exhibits excellent anti-glare properties and exhibits good contrast and wide viewing angle characteristics without occurrence of "fading" and "flashing". The resulting visual recognition decline.

[Fourth invention]

According to a fourth aspect of the invention, there is provided a liquid crystal display device comprising: a liquid crystal cell in which liquid crystal is sealed between a pair of mutually parallel cassette substrates, the liquid crystal being oriented in substantially the same direction parallel to the cassette substrate; and a front side polarizing film, The anti-glare film includes a transparent support and an anti-glare layer, and the anti-glare layer is disposed on the transparent side of the liquid crystal cell, and is disposed on the opposite side of the liquid crystal cell; a fine concavo-convex surface having fine concavities and convexities on the opposite side of the transparent support, and the anti-glare film is disposed opposite to the surface of the front-side polarizing film facing the liquid crystal cell so that the anti-glare layer is the most recognizable side. The side surface is characterized in that the internal haze of the antiglare film is 1% or less, and the surface haze is 0.4% or more and 10% or less, and is incident on the main normal direction of the average surface of the fine uneven surface, and The surface of the fine uneven surface includes a plane having the highest elevation and a plane parallel to the average surface of the fine uneven surface, that is, a plane having a wavelength of 550 nm which is emitted from the highest elevation plane. The complex amplitude of the above-mentioned highest elevation surface is calculated from the elevation of the above-mentioned fine concave-convex surface and the refractive index of the anti-glare layer; the one-dimensional power spectrum of the complex amplitude is expressed as the intensity of the spatial frequency, at the spatial frequency It has two inflection points in the range of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less.

In one aspect of the liquid crystal display device of the fourth aspect of the invention, it is preferable that the liquid crystal cell side surface of the front side polarizing film does not have a transparent protective film, and the front side polarizing film is directly bonded to the front side of the liquid crystal cell. surface.

Further, in one aspect of the liquid crystal display device of the fourth aspect of the invention, it is preferable that the liquid crystal cell side surface of the front side polarizing film has a transparent protective film, and the thickness direction phase difference R _{th of} the transparent protective film is - In the range of 10 nm to +40 nm. In this case, the transparent protective film is preferably composed of a cellulose acetate resin or a norbornene resin.

In one aspect of the liquid crystal display device of the fourth aspect of the invention, it is preferable that the second-order derivative function relating to the spatial frequency of the one-dimensional power spectrum of the complex amplitude is positive when the spatial frequency is 0.024 μm ^-1 .

In one aspect of the liquid crystal display device of the fourth aspect of the invention, it is preferable that the ratio of the micro-faces having an inclination angle of 5 or more in the fine uneven surface is less than 10%.

The liquid crystal display device of the fourth invention exhibits excellent anti-glare properties, exhibits good contrast and wide viewing angle characteristics, and prevents visual recognition degradation caused by occurrence of "fading" and "flashing".

[A first embodiment of the present invention]

<Anti-glare film>

Hereinafter, the best mode for carrying out the first invention will be described in detail.

The anti-glare film of the first aspect of the invention includes a transparent support and an anti-glare layer, and the anti-glare layer is formed on the transparent support and has a fine uneven surface having fine irregularities on a side opposite to the transparent support. Further, the anti-glare film has an internal haze of 1% or less and a surface haze of 0.4% or more and 10% or less.

In addition, the anti-glare film of the first aspect of the invention has a feature that the wavelength is 550 nm which is irradiated in the main normal direction perpendicular to the average surface of the fine uneven surface and is incident from the side of the transparent support and emitted from the side of the anti-glare layer. The plane wave, the complex amplitude of the highest elevation surface is calculated from the elevation of the above-mentioned fine concave surface and the refractive index of the antiglare layer, and the one-dimensional power spectrum of the complex amplitude is expressed as the intensity of the spatial frequency, The spatial frequency is in the range of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less, and has two inflection points. Here, the average surface of the fine uneven surface refers to a plane obtained from the average value at the time of measuring the elevation of the fine uneven surface. The highest elevation plane is a virtual plane parallel to the average surface of the fine uneven surface, and is a plane including the point of the highest elevation in the fine uneven surface.

The period of the fine uneven surface of the antiglare film has been evaluated by the average length RSm of the roughness curve elements described in JIS B 0601, the average length PSm of the section curve elements, and the average length WSm of the waviness curve elements. However, in such a conventional evaluation method, it is not possible to accurately evaluate a plurality of cycles included in the fine uneven surface. Therefore, the relationship between the glare and the fine uneven surface and the relationship between the anti-glare property and the fine uneven surface cannot be accurately evaluated, and it is difficult to produce an anti-glare film which has both suppression of glare and sufficient anti-glare property. .

The present inventors have found that in the antiglare film including the transparent support and the antiglare layer (which is formed on the transparent support and provided with fine uneven surfaces having fine irregularities on the side opposite to the transparent support), The complex amplitude of the above-mentioned plane wave of the highest elevation surface shows a specific spatial frequency distribution, which not only exhibits a sufficient anti-glare effect, but also sufficiently prevents dizziness. Here, the "complex amplitude of the plane wave of the highest elevation surface" is a value calculated from the elevation of the fine uneven surface and the refractive index of the antiglare layer. In other words, according to the first aspect of the invention, the shape of the fine uneven surface of the anti-glare film is such that the inflection point of the one-dimensional power spectrum of the complex amplitude is within a specific range. Thus, the first invention can provide an anti-glare film which exhibits both excellent anti-glare properties and prevents deterioration of visual recognition due to fading, and is not disposed on the surface of a high-definition image display device. High contrast occurs when glare occurs.

First, the elevation of the fine uneven surface of the anti-glare film (anti-glare layer) will be described. Fig. 1 is a perspective view schematically showing the surface of the anti-glare film of the first invention. As shown in Fig. 1, the anti-glare film 1 of the first aspect of the invention includes an anti-glare layer, and the anti-glare layer has a fine uneven surface on which fine irregularities 2 are formed.

The "elevation of the fine uneven surface" as used in the first aspect of the present invention means that the arbitrary normal point P on the surface of the anti-glare film 1 and the elevation reference surface (the elevation is used as a reference of 0 μm) are in the main normal direction (perpendicular to the elevation reference). The straight line distance of the direction of the face. Here, the elevation reference plane is a virtual plane parallel to the average surface of the fine uneven surface, and is a plane including a point having the lowest elevation when measuring the elevation of the fine uneven surface. As shown in Fig. 1, when the rectangular coordinate in the average plane of the fine uneven surface is represented by (x, y), the height of the fine uneven surface of the coordinate (x, y) is h (x, y). In the first drawing, the projection surface 3 which is a plane on which the entire surface of the anti-glare film 1 is projected is shown.

The three-dimensional information of the surface shape measured by a device such as a confocal microscope, an interference microscope, or an atomic energy microscope (AFM) can be obtained from the elevation of the fine uneven surface. The horizontal resolution required by the measuring instrument is at least 5 μm or less, preferably 2 μm or less, and the vertical resolution is at least 0.1 μm or less, preferably 0.01 μm or less. As a non-contact three-dimensional surface shape/roughness measuring instrument suitable for the measurement, a New View 5000 series (developed by Zygo Corporation, available from Zygo Co., Ltd. in Japan), a three-dimensional microscope PLμ2300 (developed by Sensofar) can be cited. Wait. In terms of the measurement area, since the resolution of the two-dimensional power spectrum requiring a complex amplitude is 0.008 μm ^-1 or less, it is preferably at least 125 μm × 125 μm or more, more preferably 500 μm × 500 μm or more.

Fig. 2 is a view schematically showing the elevation h(x, y) of the fine concavo-convex surface and the elevation reference surface 20 (including the point having the lowest elevation when measuring the elevation of the fine concavo-convex surface and parallel to the average surface of the fine concavo-convex surface) The relationship between the imaginary plane and the highest elevation surface 21 (including a virtual plane having the highest elevation in the fine uneven surface and parallel to the average surface of the fine uneven surface). Here, the elevation of the highest elevation surface 21 is set to h _max (μm).

The optical path length d(x, y) between the elevation reference plane 20 and the highest elevation plane 21 at coordinates (x, y) can be expressed by the two-dimensional function h(x, y) associated with the elevation (1) To represent.

[Math 1]

d ( x , y )= n _AG h ( x , y )+ n _air [ h _max - h ( x , y )] (1)

Here, n _AG is the refractive index of the antiglare layer, and n _air is the refractive index of air. Here, when the refractive index n _{air of the air is} approximately 1, the formula (1) can be expressed by the formula (2).

[Math 2]

d ( x , y )=( n _AG -1) h ( x , y )+ h _max (2)

Next, the plane wave at the single wavelength λ is irradiated along the main normal direction 5 of the film (the direction perpendicular to the average surface of the fine uneven surface) and is incident from the transparent support side (the elevation reference surface 20 side) on the anti-glare layer side. The complex amplitude of the plane wave in the case where the (highest elevation surface 21 side) is emitted will be described. The complex amplitude refers to a portion that does not include a time element when the fluctuation amplitude is expressed in a plural form. The amplitude of a plane wave of a single wavelength λ can be generally expressed in the plural form by the following formula (3).

[Math 3]

Here, A is the maximum amplitude of the plane wave, π is the pi, i is the imaginary unit, z is the coordinate of the z-axis direction (main normal direction 5) (length of the optical path from the origin), ω is the angular frequency, t is Time, ψ ₀ is the initial phase.

In equation (3), the term that does not depend on time is a complex amplitude. Therefore, the complex amplitude ψ(x, y) of the coordinates (x, y) of the plane wave represented by the equation (3) at the highest elevation plane 21 can be used in the time-independent term of the equation (3). The optical path length d (x, y) is represented by the following formula (4) in which z is substituted.

[Math 4]

Further, in the equation (4), the maximum amplitude A and the initial phase ψ _{0 of the} plane wave are not dependent on the coordinates (x, y), and the shape distribution of the fine uneven surface at the coordinates (x, y) is specified. In the first invention, it is constant, and therefore, A = 1 and ψ ₀ = 0 are assumed as follows. Further, when the above formula (2) is substituted, the complex amplitude Ψ(x, y) can be expressed by the following formula (5). Further, in the first invention, λ = 550 nm is used as a reference.

[Math 5]

Next, a method of obtaining a power spectrum of a complex amplitude will be described. First, the two-dimensional function Ψ(f _x , f _y ) is obtained from the two-dimensional function ψ(x, y) expressed by the equation (5) by the two-dimensional Fourier transform defined by the equation (6).

[Math 6]

Here, f _x and f _y are spatial frequencies in the x direction and the y direction, respectively, and have a reciprocal of the length. By two-dimensional function Ψ (f _x, f _y) obtained square, the complex amplitude can be obtained a two-dimensional power spectrum ^{_{Ψ 2 (f x, f y}} ). The two-dimensional power spectrum Ψ ² (f _x , f _y ) represents a spatial frequency distribution of complex amplitudes calculated from the elevation of the fine uneven surface of the anti-glare film.

Next, a method of obtaining a two-dimensional power spectrum of a complex amplitude calculated from the elevation of the fine uneven surface of the anti-glare film will be specifically described. The three-dimensional information of the surface shape actually measured by the above-described confocal microscope, interference microscope, atomic energy microscope, or the like is usually obtained as a discrete value, that is, an elevation corresponding to a plurality of measurement points. Fig. 3 is a schematic diagram showing a state in which the function h(x, y) indicating the elevation is discretely obtained. As shown in Fig. 3, when the rectangular coordinate in the plane of the film is represented by (x, y) and is divided by the line Δx in the x-axis direction and every △ in the y-axis direction on the film projection surface 3. When the line divided by y is indicated by a broken line, in actual measurement, the elevation of the fine uneven surface is obtained as a discrete elevation value at the intersection of the respective broken lines on the film projection surface 3.

The number of the obtained elevation values is determined by the measurement range and Δx and Δy, as shown in Fig. 3, when the measurement range in the x-axis direction is set to X = (M-1) Δx, and the measurement in the y-axis direction When the range is set to Y=(N-1)Δy, the number of elevation values obtained is M×N.

As shown in Fig. 3, the coordinates of the point of view A on the film projection surface 3 are (j?x, k?y) (here, j is 0 or more and M-1 or less, and k is 0 or more and N When -1 or less), the elevation of the point P on the film surface corresponding to the eye point A can be expressed as h (j Δx, k Δy).

Here, the measurement intervals Δx and Δy depend on the horizontal resolution of the measuring instrument, and in order to accurately evaluate the fine uneven surface, as described above, it is preferable that both Δx and Δy are 5 μm or less, and more preferably 2 μm or less. Further, as described above, the measurement ranges X and Y are preferably 125 μm or more, and more preferably 500 μm or more.

Thus, in the actual measurement, the function indicating the elevation of the fine uneven surface is obtained as a discrete function h(x, y) having M × N values. From the discrete function h(x, y) obtained by the measurement, the complex amplitude Ψ(x, y) represented by the equation (5) is obtained, and is defined by the complex amplitude Ψ(x, y) and by the equation (7) The discrete Fourier transform is used to find the discrete function Ψ(f _x ,f _y ). By squaring the discrete function Ψ(f _x ,f _y ), the discrete function 二维^{2 of} the two-dimensional power spectrum is obtained (f _x ,f _y ). 1 in the formula (7) is an integer of -M/2 or more and M/2 or less, and m is an integer of -N/2 or more and N/2 or less. Further, Δf _x and Δf _y are frequency intervals in the x direction and the y direction, respectively, and are defined by the equations (8) and (9).

[Math 7]

[Math 8]

[Math 9]

Here, as shown in Fig. 4, the fine uneven surface of the anti-glare film of the first aspect of the invention is randomly formed by the unevenness, so the two-dimensional power spectrum Ψ ² (f _x , f _y in the frequency space (spatial frequency region) ) is symmetric with respect to the origin (f _x =0, f _y =0). Thus, the two-dimensional function Ψ ² (f _x , f _y ) can be transformed into a one-dimensional function Ψ ² (f) with a distance f (unit: μm ^-1 ) from the origin in the frequency space. The anti-glare film of the first aspect of the invention has the feature that the one-dimensional power spectrum obtained from the one-dimensional function Ψ ² (f) is constant.

Specifically, first, as shown in FIG. 5, in the frequency space, the pair is located at an origin of O (f _x =0, f _y =0) is (n-1/2) Δf or more and is insufficient (n). +1/2) The number N _n of all the points of the distance Δf (black circles in Fig. 5) is calculated. In the example shown in Fig. 5, N _n = 16. Next, the total value of Ψ ² (f _x , f _y ) at all points of the distance (n-1/2) Δf or more and less than (n+1/2) Δf from the origin OΨ ² _n (the total value of Ψ ² (f _x , f _y ) of the black dot in Fig. 5) is calculated as shown in equation (10), and the total value Ψ ² _{n is} divided by the number of points N The value obtained is taken as the value of Ψ ² (f).

[Math 10]

Here, in the case of M≧N, n is an integer of 0 or more and N/2 or less; and in the case of M<N, n is an integer of 0 or more and M/2 or less. Further, as shown in FIG. 3, M and N mean the number of measurement points in the x-axis direction and the number of measurement points in the y-axis direction, respectively. Further, Δf is (Δf _x + Δf _y )/2.

Figure 6 shows the one-dimensional power spectrum Ψ ² (f) of the complex amplitude thus obtained. The one-dimensional power spectrum shown in Fig. 6 contains noise. When the inflection point of the one-dimensional power spectrum is sought, in order to eliminate the influence of the noise, it is transformed into a dispersion of every 0.008 μn ^-1 by linear interpolation. Function to reduce noise. Fig. 7 shows a state in which the one-dimensional power spectrum Ψ ² (f) is transformed into a discrete function of every 0.008 μm ^-1 by linear interpolation. In the example of Fig. 7, the value of the spatial frequency of 0.016 μm ^-1 is linearly interpolated, and the largest spatial frequency, which is a spatial frequency smaller than the spatial frequency of 0.016 μm ^-1 , is 153 ² (f) of 0.0153 μm ^-1 . ) value than 0.016μm ^-1 17.7915 and large spatial frequencies a spatial frequency i.e., the smallest of 0.0164μm ^-1 Ψ ² (f) the value of 16.1581, a spatial frequency calculated value of 16.8135 0.016μm ^-1. Fig. 8 shows the result of transforming the one-dimensional power spectrum Ψ ² (f) of Fig. 6 into a discrete function of a spatial frequency of 0.008 μm ^-1 . It can be seen that the one-dimensional power spectrum Ψ ² (f) noise after conversion to a discrete function of a spatial frequency of 0.008 μm ^-1 is small.

The inflection point of the one-dimensional power spectrum Ψ ² (f) of the complex amplitude can be calculated from the second-order derivative function of the one-dimensional power spectrum Ψ ² (f) of the discrete function with a spatial frequency of 0.008 μm ^-1 . Specifically, the second derivative function can be calculated using the difference method of equation (11).

[Math 11]

Figure 9 shows the second-order derivative of the one-dimensional power spectrum Ψ ² (f) of Figure 8. As can be seen from Fig. 9, the second derivative function d ² Ψ ² (f)/df ² is twice in the range of the spatial frequency of 0.032 μm ^-1 or more and 0,064 μm ^-1 or less and the horizontal axis (d ² Ψ ² (f)/df ² =0) crossover, in the range of the spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less, the side having a low spatial frequency has a reverse point which is negative from the positive direction, and has a side having a high spatial frequency. A reversal point from negative to positive. In addition, the "reflexion point" of the graph when the one-dimensional power spectrum of the complex amplitude is expressed as the intensity of the spatial frequency is the same as the general term, and is the one-dimensional power spectrum Ψ ² (f) The second derivative function d ² Ψ ² (f)/df ² becomes a point on the graph of the one-dimensional power spectrum Ψ ² (f) corresponding to the spatial frequency of zero.

Further, in the anti-glare film of the first aspect of the invention, in order to efficiently prevent glare and obtain a sufficient anti-glare effect, the second-order derivative function d ² Ψ ² (f)/df ² of the one-dimensional power spectrum of the complex amplitude is When the spatial frequency is 0.024 μm ^-1 , it is preferably positive. That is, the one-dimensional power spectrum of the complex amplitude preferably has a convex downward shape at a spatial frequency of 0.024 μm ^-1 .

Next, the relationship between the one-dimensional power spectrum of the complex amplitude calculated from the elevation of the fine uneven surface and the refractive index of the antiglare layer, and the antiglare effect and the glare of the antiglare film will be described.

(Evaluation of anti-glare effect)

The antiglare effect of the antiglare film can be evaluated by the reflectance of the reflection measured by the method specified in JIS K 7105. In this specification, the reflection sharpness is obtained by using four kinds of optical combs having a width ratio of a dark portion and a bright portion of 1:1 and a width of 0.125 mm, 0.5 mm, 1.0 mm, and 2.0 mm at an incident angle of light 45. ° The measured brightness is expressed as the sum of the sharpness (unit: %). However, in the case of using an optical comb having a width of 0.125 mm, in the anti-glare film specified by the first invention, the measurement error of the sharpness is large, and therefore, in the reflection sharpness of the first invention, The sharpness is measured by using an optical comb having a width of 0.125 mm, and the sum of sharpness measured by using three kinds of optical combs having widths of 0.5 mm, 1.0 mm, and 2.0 mm is called reflection sharpness. Therefore, the maximum value of the reflection sharpness thus defined is 300%. The smaller the reflection sharpness is, the higher the anti-glare effect of the anti-glare film is.

Regarding the anti-glare film having various fine uneven surfaces, the intensity and reflection of the one-dimensional power spectrum Ψ ² (f) of the complex amplitude at each spatial frequency in the range of the spatial frequency of 0.0024 to 0.3 μm ^-1 The correlation between degrees is analyzed. As a result, it is understood that the intensity of Ψ ² (f) having a spatial frequency of 0.03 μm ^-1 is increased, the reflection sharpness is efficiently reduced, and the anti-glare effect is improved. Fig. 10 shows the relationship between the intensity of Ψ ² (f) and the reflection sharpness at a spatial frequency of 0.03 μm ^-1 . As can be seen from the figure, in order to improve the antiglare effect of the antiglare film, it is necessary to increase the intensity of the one-dimensional power spectrum Ψ ² (f) of a complex amplitude at a spatial frequency of 0.03 μm ^-1 .

(evaluation of dizziness)

On the other hand, the glare of the anti-glare film was evaluated by the following method. That is, a photo mask having a unit pattern as shown in the plan view of Fig. 11 is first prepared. In the figure, the unit 40 forms a key-shaped chrome-shielding pattern 41 having a line width of 10 μm on the transparent substrate, and a portion where the chrome-shielding pattern 41 is not formed is the opening portion 42. Here, since the size of the cell is 211 μm × 70 μm (vertical × horizontal in the drawing), a pattern having an opening size of 201 μm × 60 μm (vertical × horizontal in the drawing) is used. Many of the illustrated units are juxtaposed side by side to form a reticle.

Then, as shown in the schematic cross-sectional view of Fig. 12, the chrome-shielding pattern 41 of the mask 43 is placed on the diffusion plate 50 on the light box 45 in the upper side, and the adhesive is used. The anti-glare film 1 is placed on the photomask 43 with a sample in which the uneven surface is bonded to the glass plate 47 so that the uneven surface thereof becomes a surface. A light source 46 is disposed in the light box 45. In this state, the degree of glare was evaluated by seven levels by visual observation at a position 49 of about 30 cm from the sample. The first stage is in a state where no dizziness is seen at all, the seventh level is equivalent to the state in which strong dizziness is observed, and the fourth level is a state in which a slight dizziness is observed.

Regarding the anti-glare film having various fine uneven surfaces, the intensity of the one-dimensional power spectrum Ψ ² (f) of the complex amplitude at each spatial frequency in the range of the spatial frequency of 0.0024 to 0.3 μm ^-1 and the above-mentioned flash When the correlation between the evaluation results of the glare was analyzed, it was found that the degree of glare increased by increasing the intensity at a spatial frequency of 0.02 μm ^-1 . Fig. 13 shows the relationship between the intensity of Ψ ² (f) and the reflection sharpness at a spatial frequency of 0.02 μm ^-1 . As can be seen from the figure, in order to prevent the glare of the anti-glare film, it is necessary to reduce the intensity of the one-dimensional power spectrum Ψ ² (f) of the complex amplitude having a spatial frequency of 0.02 μm ^-1 .

As described above, the anti-glare film of the first aspect of the invention is characterized in that the one-dimensional power spectrum of the complex amplitude calculated from the elevation of the surface of the fine uneven surface is in a range of a spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less. Has two inflection points. In addition, the second-order derivative function related to the spatial frequency of the one-dimensional power spectrum of the complex amplitude is preferably positive when the spatial frequency is 0.024 μm ^-1 . The first anti-glare film of the present invention which exhibits such a frequency distribution (one-dimensional power spectrum) has a one-dimensional power spectrum Ψ ² (f) of a complex amplitude having a downward convex shape at a spatial frequency of around 0.02 μm ^-1 After the spatial frequency is 0.03 μm ^-1 , the one-dimensional power spectrum Ψ ² (f) of the complex amplitude has an upward convex shape, and a one-dimensional power spectrum of the complex amplitude at a spatial frequency of around 0.01 μm ^{-1 2} (f) has a downward convex shape. As a result, it is possible to reduce the intensity of the one-dimensional power spectrum Ψ ² (f) of the complex amplitude at a spatial frequency of 0.02 μm ^-1 which is the cause of the occurrence of glare, and it is possible to improve the space which contributes to the anti-glare effect. The intensity of the one-dimensional power spectrum Ψ ² (f) of complex amplitude with a frequency of 0.03 μm ^-1 . In addition, it is possible to reduce a high spatial frequency component of 0.1 μm ^-1 or more by causing the anti-glare property to function inefficiently and scattering light incident on the surface of the fine uneven surface to cause fading.

Further, the present inventors have found that, in the anti-glare film, when each of the minute faces constituting the fine uneven surface shows a specific inclination distribution, it exhibits excellent anti-glare performance and is more effective in preventing fading efficiently. In other words, in the anti-glare film of the first aspect of the invention, the ratio of the micro-faces having an inclination angle of 5 or more in the fine uneven surface is less than 10%. When the ratio of the micro-faces having an inclination angle of 5 or more in the fine uneven surface is more than 10%, the minute surface of the uneven surface having a steep inclination angle is increased, and the light from the surroundings is concentrated, and the display surface is easily changed as a whole. White faded. In order to suppress such a condensing effect and prevent fading, the ratio of the minute surface having an inclination angle of 5 or more in the fine uneven surface is preferably as small as possible, and is preferably less than 5%, more preferably less than 2%.

Here, the "inclination angle of the minute surface of the fine uneven surface" as used in the first aspect of the present invention means that the above-mentioned inclusion point is formed at any point P on the surface of the anti-glare film 1 shown in Fig. 1 The unevenness of the minute surface of P takes into consideration the angle θ formed by the normal line 6 of the local portion and the main normal direction 5 of the film. The inclination angle of the fine uneven surface can be obtained from the three-dimensional information of the surface shape measured by a device such as a confocal microscope, an interference microscope, or an atomic energy microscope (AFM), similarly to the elevation.

Fig. 14 is a schematic view for explaining a method of measuring the inclination of the minute surface of the fine uneven surface. When the method of determining the specific inclination angle is described, as shown in FIG. 14, the eye point A on the virtual plane FGHI indicated by the broken line is determined, and near the eye point A on the x-axis passing through the eye point A, Points B and D are obtained substantially symmetrically with respect to point A; and points C and E are obtained substantially symmetrically with respect to point A in the vicinity of eye point A on the y-axis passing through eye point A, thereby determining the four Points Q, R, S, and T on the film surface corresponding to points B, C, D, and E. Further, in Fig. 14, the rectangular coordinates in the plane of the film are represented by (x, y), and the coordinates in the thickness direction of the film are represented by z. The plane FGHI is a line passing through a point C on the y-axis and parallel to the x-axis and passing through a point E on the same y-axis and parallel to the x-axis and passing through a point B on the x-axis and parallel to the y-axis The straight line and the surface formed by the intersections F, G, H, and I of the straight line passing through the point D on the same x-axis and parallel to the y-axis. Further, in Fig. 14, the position of the actual film surface is located above the plane FGHI, and of course, the position of the actual film surface is sometimes located by the position at which the eye point A is obtained. Above the plane FGHI, sometimes below.

Moreover, the inclination angle of the obtained surface shape data can be obtained by the polar angle of the local normal (vector) 6 (the angle θ formed with the main normal direction 5 of the film in Fig. 1) Further, it is obtained that the local normal (vector) 6 is an actual film corresponding to the point P on the actual film surface corresponding to the point of view A and the four points B, C, D, and E obtained in the vicinity thereof. The normal vectors 6a, 6b, 6c of the four planes of the polygons (ie, the four triangles PQR, PRS, PST, PTQ) of the total of the points Q, R, S, and T on the surface And 6d averaged. For each measurement point (micro surface), after obtaining the inclination angle, the histogram is calculated.

Fig. 15 is a graph showing an example of a histogram of the inclination distribution of the minute surface of the fine uneven surface of the anti-glare film. In the graph shown in Fig. 15, the horizontal axis is the inclination angle and is divided by a scale of 0.50. For example, the leftmost straight bar indicates the distribution of the set in which the inclination angle is in the range of 0 to 0.5°, and below, from left to right, the scale is increased by 0.5° by the angle. In the figure, each of the two scales on the horizontal axis represents the upper limit value of the value, and for example, the portion having "1" on the horizontal axis represents the distribution of the set of minute faces whose inclination angle is in the range of 0.5 to 1°. Further, the vertical axis indicates the ratio with respect to the entire collection, and is a value that becomes 1 if the total is obtained. In this example, the ratio of the minute faces having an inclination angle of 5 or more is substantially zero.

Further, the surface haze of the first anti-glare film of the present invention is preferably 0.4% or more and 10% or less, and the internal haze is preferably 1% or less. Here, the surface haze and the internal haze of the anti-glare film were measured as described above. In other words, first, after the antiglare layer is formed on the transparent support, the antiglare film and the glass substrate are pasted with a transparent adhesive so that the side of the transparent support in which the antiglare layer is not formed becomes the joint surface. Then, light was incident from the side of the glass substrate, and the haze was measured based on JIS K 7136. The haze thus measured corresponds to the full haze of the anti-glare film. Next, the triacetyl cellulose film having a haze of approximately 0 was bonded to the surface of the fine concavo-convex shape of the antiglare layer with glycerin, and the haze was measured again based on JIS K 7136. In terms of the haze, the surface haze caused by the fine uneven shape is substantially eliminated by the triacetyl cellulose film attached to the surface unevenness, and thus can be regarded as the "internal haze of the anti-glare film". ". Therefore, the "surface haze" of the anti-glare film is obtained from the following formula (12).

Surface haze = full haze - internal haze (12)

The surface haze of the anti-glare film is 10% or less from the viewpoint of suppressing fading, and is preferably 5% or less in order to more effectively suppress fading. For the same reason, the surface haze is preferably 4.3% or less. On the other hand, in order to obtain sufficient anti-glare property, the surface haze is preferably 0.4% or more, more preferably 10% or more. For the same reason, the surface haze is more preferably 2.7% or more. In addition, when the anti-glare film of the first aspect of the invention is disposed on the surface of the image display device, the internal haze needs to be 1% or less from the viewpoint of efficiently exhibiting high contrast. Further, for the same reason, the internal haze is preferably 0.1% or less.

The conventional anti-glare film is produced by coating a resin solution in which fine particles are dispersed on a transparent support, and adjusting the thickness of the coating film to expose the fine particles to the surface of the coating film, thereby forming random irregularities on the surface. Chip. In the antiglare film produced by dispersing fine particles, in order to eliminate glare, a refractive index difference is often provided between the binder resin and the fine particles to scatter light, and the internal haze is intentionally imparted. When such an anti-glare film is disposed on the surface of the image display device, the contrast is lowered by scattering of light at the interface between the fine particles and the adhesive resin. On the other hand, in the anti-glare film of the first aspect of the invention, as described above, since the frequency distribution (one-dimensional power spectrum) of the complex amplitude calculated from the elevation of the surface of the fine uneven surface is appropriately designed, it is not necessary. Scatter light to eliminate glare. Therefore, the internal haze which is a cause of the decrease in contrast is preferably as small as possible.

<Method for Producing Anti-Glare Film>

In the anti-glare film of the first aspect of the invention, in order to obtain the above-described complex amplitude frequency distribution (one-dimensional power spectrum) with high precision, it is preferable to use a one-dimensional power spectrum at a spatial frequency of more than 0 μm ^-1 and 0.04 μm ^-1 or less. A pattern having a maximum value and having a maximum value in a range of a spatial frequency of more than 0.04 μm ^-1 and 0.08 μm ^-1 or less is produced. Here, the "pattern" means image data for forming a fine uneven surface of the first anti-glare film of the present invention, a mask having a light transmitting portion and a light blocking portion, and the like.

The two-dimensional power spectrum of the pattern is obtained by calculation, that is, for example, in the case where the pattern is image data, after the image data is converted into binarized image data of two gradation (gradation), The two-dimensional function g(x, y) is used to represent the gradation of the image data, the obtained two-dimensional function g(x, y) is Fourier transformed, and the two-dimensional function G(f _x , f _y ) is calculated, and then The resulting two-dimensional function G(f _x , f _y ) is squared. Here, x and y represent rectangular coordinates in the plane of the image data, and f _x and f _y represent the frequency in the x direction and the frequency in the y direction.

As in the case of the two-dimensional power spectrum of the complex amplitude of the fine uneven surface of the antiglare layer, the same is true for the two-dimensional power spectrum of the pattern, and the two-dimensional function g(x, y) of the gradation is set as a discrete function. The situation that comes to it is the usual situation. In this case, as in the case of the two-dimensional power spectrum for finding the complex amplitude, the two-dimensional power spectrum may be calculated by the discrete Fourier transform. Like the one-dimensional power spectrum of the complex amplitude, the one-dimensional power spectrum of the pattern is obtained from the two-dimensional power spectrum of the pattern.

Fig. 16 is a view showing a part of image data which is a pattern used for producing the anti-glare film of the first invention. The image data shown in Fig. 16 is 33 mm × 33 mm in size and is made at 12,800 dpi.

Figure 17 is a two-dimensional power spectrum G(f _x , f _y ) obtained by discrete Fourier transform of the two-dimensional discrete function g(x, y) of the gradation shown in Fig. 16 and the complex amplitude The one-dimensional power spectrum is similarly represented as a function of the distance f from the origin. The figure shows that the pattern shown in Figure 16 has a maximum value at 0.063μm ^-1 spatial frequencies, but does not have the spatial frequency is greater than a maximum value in the range of 0 m ^{-1 -1} and 0.04 m or less.

In the case where the one-dimensional power spectrum of the pattern for producing the anti-glare film (anti-glare layer) has a maximum value when it is larger than 0 μm ^-1 and 0.04 μm ^-1 or less, as a result, the complex amplitude of the obtained anti-glare film The one-dimensional power spectrum does not have a downward convex shape when the spatial frequency is around 0.02 μm ^-1 . Further, in the case where the one-dimensional power spectrum of the pattern does not have a maximum value when it is larger than 0.04 μm ^-1 and 0.08 μm ^-1 or less, as a result, the one-dimensional power spectrum of the complex amplitude of the obtained anti-glare film is at a spatial frequency. There is no 向上 having an upward convex shape after 0.03 μm ^-1 . Therefore, the elimination of the glare and the sufficient anti-glare property cannot be achieved.

In order to form a pattern having a maximum value when the one-dimensional power spectrum is greater than 0 μm ⁻¹ and 0.04 μm ⁻¹ or less, and having a maximum value when it is greater than 0.04 μm ⁻¹ and 0.08 μm ⁻¹ or less, as long as it has 10 μm or more and is insufficient The dots of 20 μm in diameter can be randomly and uniformly arranged. The diameter of the randomly arranged dots may be one type or multiple types. Further, in order to more effectively from such a point randomly arranged pattern made by removing a spatial frequency component of 0.04μm ^-1 or less, the frequency can also be used through the following components 0.04μm ^-1 i.e. the removal of a particular spatial The pattern obtained by the high-pass filter is used as a pattern for producing an anti-glare film. In addition, in order to more effectively remove a component having a spatial frequency of 0.04 μm ^-1 or less from a pattern in which dots are randomly arranged, and having a maximum value when it is larger than 0.04 μm ^-1 and 0.08 μm ^-1 or less, A pattern obtained by passing a band pass filter that removes a component having a specific spatial frequency of less than 0.04 μm ^-1 and a component having a specific spatial frequency of 0.08 μm ^-1 or less, or a specific spatial frequency or more, can be used as an anti-glare film. pattern. In the case of patterning by a method of passing through a high-pass filter, a band-pass filter, or the like, as a pattern before passing through the filter, randomization having a darkness determined by a random number or a computer-generated simulated random number may also be used. The pattern of the brightness distribution.

In the antiglare film of the first aspect of the invention, as described above, the spatial frequency distribution of the fine uneven surface of the antiglare layer is preferably suitably formed. Therefore, the anti-glare film of the first aspect of the invention is preferably produced by an embossing method in which a mold having a fine uneven surface is produced by the above-described pattern, and the unevenness of the produced mold is obtained. The photocurable resin layer or the like which has been transferred onto the transparent support is surface-released, and then the antiglare layer and the transparent support which have transferred the uneven surface are peeled off from the mold to produce an antiglare film.

Here, as the embossing method, a UV embossing method using a photocurable resin and a hot embossing method using a thermoplastic resin are exemplified, and from the viewpoint of productivity, a UV embossing method is preferred.

In the UV embossing method, a photocurable resin layer is formed on the surface of a transparent support, and the photocurable resin layer is pressed against the uneven surface of the mold to be solidified, whereby the uneven surface of the mold is transferred. A method of using a photocurable resin layer. Specifically, the ultraviolet curable resin is applied to the transparent support, and the ultraviolet curable resin is cured by irradiating ultraviolet rays from the transparent support side while the coated ultraviolet curable resin is in close contact with the uneven surface of the mold. Thereafter, the transparent support having the cured ultraviolet curable resin layer formed thereon is peeled off from the mold, whereby the shape of the mold is transferred to the ultraviolet curable resin.

In the case of the UV embossing method, the transparent support may be a film which is substantially optically transparent, and examples thereof include a triacetyl cellulose film, a polyethylene terephthalate film, and a poly A solvent-cast film such as a methyl methacrylate film, a polycarbonate film, or a thermoplastic resin such as an amorphous cyclic polyolefin having a norbornene-based compound as a monomer, and a resin film such as an extruded film.

In addition, the type of the ultraviolet curable resin in the case of the UV embossing method is not particularly limited, and a commercially available suitable resin can be used. Further, a resin in which a photoinitiator which is appropriately selected is combined with an ultraviolet curable resin and which is curable by visible light having a longer wavelength than ultraviolet rays can also be used. Specifically, a polyfunctional acrylate such as trimethylolpropane triacrylate or pentaerythritol tetraacrylate is used alone or in combination of two or more kinds thereof, and trishydroxymethyl group is preferred. Polyfunctional acrylates such as propane triacrylate and pentaerythritol tetraacrylate, and IRGACURE 907 (developed by Ciba specialty chemicals), IRGACURE 184 (developed by Ciba specialty chemicals), 2,4,6-trimethylbenzylidene - Photopolymerization initiators such as diphenylphosphine oxide (Lucirin) TPO (developed by BASF Corporation) are used in combination.

On the other hand, the hot embossing method is a method in which a transparent support formed of a thermoplastic resin is pressed against a mold in a heated state and the surface shape of the mold is transferred to a transparent support. As the transparent support used in the hot embossing method, if it is a substantially transparent support, what kind of support can be used, for example, polymethyl methacrylate, polycarbonate, polyethylene terephthalate can be used. A solvent cast film, an extruded film, or the like of a thermoplastic resin such as a glycol ester, triethyl fluorene cellulose, or an amorphous cyclic polyolefin having a norbornene compound as a monomer. These transparent resin films are also preferably used as a transparent support for coating an ultraviolet curable resin by the above UV embossing method.

<Method for Producing Mold for Manufacturing Anti-Glare Film>

Next, a method of manufacturing a mold used for the production of the anti-glare film of the first aspect of the invention will be described. In the method for producing a mold for use in the production of the anti-glare film of the first aspect of the invention, the method of obtaining a predetermined surface shape of the above-described pattern is not particularly limited, and fine irregularities are produced for high precision and good reproducibility. The surface preferably comprises substantially [1] first plating step, [2] grinding step, [3] photosensitive resin film coating step, [4] exposure step, [5] development step, [6] first etching step [7] Photosensitive resin film peeling step, [8] second etching step, [9] second plating step. Fig. 18 is a view schematically showing a preferred example of the first half of the method for producing a mold used for the production of the antiglare film of the first invention. Fig. 18 is a schematic representation of the cross section of the mold of each step. Hereinafter, each step of the method for producing a mold used for the production of the anti-glare film of the first invention will be described in detail with reference to Fig. 18.

[1] First plating step

In the method for producing a mold used in the production of the anti-glare film of the first aspect of the invention, first, the surface of the substrate used for the mold is subjected to copper plating or nickel plating. As described above, by performing copper plating or nickel plating on the surface of the substrate for a mold, it is possible to improve the adhesion and gloss of chrome plating in the subsequent second plating step. This is because copper plating or nickel plating has a high coating property and a high smoothing effect, so that fine irregularities and pores of the substrate for a mold are filled, thereby forming a flat and shiny surface. . By the characteristics of these copper plating or nickel plating, even if chrome plating is performed in the second plating step to be described later, it is considered that the roughness of the chrome-plated surface caused by minute irregularities and pores of the substrate is eliminated, and copper plating is also performed. Or nickel plating is highly coated, so the occurrence of fine cracks is reduced.

As the copper or nickel used in the first plating step, in addition to the respective pure metals, an alloy mainly composed of copper or an alloy mainly composed of nickel may be used. Therefore, the "copper" referred to in the present specification is It means copper and copper alloy, and "nickel" means nickel and nickel alloy. The copper plating and the nickel plating may be performed by electrolytic plating or by electroless plating, and usually electrolytic plating is used.

When copper plating or nickel plating is performed, when the plating layer is too thin, the influence of the surface of the substrate is not completely excluded, so the thickness thereof is preferably 50 μm or more. The upper limit of the thickness of the plating layer is not a critical value, but it is usually about 500 μm from the relationship with cost and the like.

Further, in the method for producing a mold according to the first aspect of the invention, aluminum, iron, or the like is used as a metal material which is preferably used for forming a substrate. In addition, from the convenience of use, it is more preferably lightweight aluminum. The same applies to aluminum and iron as described herein, and in addition to pure metal, an alloy mainly composed of aluminum or iron may be used.

Further, the shape of the substrate is not particularly limited as long as it is a suitable shape which has been conventionally used in the art, and may be a flat plate shape or a cylindrical or cylindrical roller. When a mold is produced using a roll-shaped base material, there is an advantage that the anti-glare film can be manufactured into a continuous roll shape.

[2] Grinding step

In the subsequent grinding step, the surface of the substrate subjected to copper plating or nickel plating in the first plating step described above is ground. In the method for producing a mold according to the first aspect of the invention, it is preferred that the surface of the substrate is ground to an approximately mirror state through the step. This is because the metal plate and the metal roll to be the base material are often subjected to machining such as cutting and grinding in order to obtain desired precision, thereby leaving machining marks on the surface of the substrate, even if copper plating is performed. In the case of nickel plating, the processing marks are often left, and in the state where plating is performed, the surface is not completely smooth. In other words, even if the surface to which such a deep processing mark or the like is left is subjected to a later-described process, unevenness such as a processing mark tends to be deeper than the unevenness formed after each step, and there is a possibility that the influence of the processing mark or the like is left. In the case where the mold is made of an anti-glare film, it tends to have an unpredictable effect on the optical characteristics. In addition, the "machining mark" refers to a fine tool mark which is generated when cutting, grinding, etc. are performed in order to make a metal which is a material of a metal plate and a metal roll into a predetermined shape and the desired precision. Fig. 18(a) is a view schematically showing a flat substrate 7 for a mold having copper plating or nickel plating on the surface thereof in the first plating step (for the copper plating or nickel plating layer formed in this step, The state of the surface 8 which has been mirror-polished by the grinding step is also shown.

The method of polishing the surface of the substrate on which copper plating or nickel plating is applied is not particularly limited, and any of a mechanical polishing method, an electrolytic polishing method, and a chemical polishing method can be used. As the mechanical polishing method, for example, a superfinishing method, a polishing, a fluid polishing method, a buffing method, or the like can be exemplified.

Further, in the polishing step, the surface 7 of the substrate for the mold may be mirror-finished by mirror-cutting using a cutting tool. The material and shape of the cutting tool at this time are not particularly limited, and a superhard tool, a CBN tool, a ceramic tool, a diamond tool, or the like can be used. However, from the viewpoint of processing accuracy, a diamond tool is preferably used. The surface roughness after polishing is preferably 0.1 μm or less, more preferably 0.05 μm or less, based on the center line average roughness Ra defined by JIS B 0601. When the center line average roughness Ra after grinding is more than 0.1 μm, there is a possibility that the influence of the surface roughness after polishing is left on the uneven shape of the final mold surface, which is not preferable. In addition, the lower limit of the center line average roughness Ra is not particularly limited, and from the viewpoint of processing time and processing cost, there is a limit naturally, and thus no special designation is required.

[3] Photosensitive resin film coating step

In the next photosensitive resin film application step, the photosensitive resin is applied to the surface 8 of the substrate 7 which has been subjected to mirror polishing by the above-described polishing step, and is coated with a solution dissolved in a solvent, followed by heating and drying. Thus, a photosensitive resin film is formed. Fig. 18(b) schematically shows a state in which the photosensitive resin film 9 is formed on the surface 8 of the substrate 7.

As the photosensitive resin, a conventionally known photosensitive resin can be used. For example, as a negative-type photosensitive resin having a property of curing a photosensitive portion, a monomer having an acrylate having a propenyl group or a methacryl group in a molecule, and a mixture of a prepolymer, a diazide, and a diene rubber can be used. And a polyvinyl cinnamate compound or the like. In addition, a phenol resin type, a phenol resin type, or the like can be used as the positive-type photosensitive resin which removes the property of only the non-photosensitive portion by the photosensitive portion by development. In addition, various additives such as a sensitizer, a development accelerator, an adhesion modifier, and a coatability improver may be mixed in the photosensitive resin as needed.

When these photosensitive resins are applied to the surface 8 of the substrate 7, in order to form a good coating film, it is preferably diluted with a suitable solvent and applied, and a cellosolve solvent or a propylene glycol solvent can be used. An ester solvent, an alcohol solvent, a ketone solvent, a highly polar solvent, or the like.

As a method of applying the photosensitive resin solution, meniscus coating, fountain blade coating, dip coating, spin coating, roll coating, screw extrusion coating, air knife coating, blade coating, curtain coating, circumferential coating, etc. may be used. A well-known method. The thickness of the coating film is preferably in the range of 1 to 6 μm after drying.

[4] Exposure step

In the next exposure step, the one-dimensional power spectrum described above does not have a maximum value when it is greater than 0 μm ^-1 and 0.04 μm ^-1 or less, and has a maximum value when it is greater than 0.04 μm ^-1 and 0.08 μm ^-1 or less. The pattern is exposed on the photosensitive resin film 9 formed by the above-described photosensitive resin film coating step. The light source used in the exposure step may be appropriately selected according to the photosensitive wavelength and sensitivity of the photosensitive resin after application, and for example, a g line (wavelength: 436 nm) of a high pressure mercury lamp or an h line of a high pressure mercury lamp (wavelength: 405 nm) can be used. ), i-line (wavelength: 365 nm) of high-pressure mercury lamp, semiconductor laser light (wavelength: 830 nm, 532 nm, 488 nm, 405 nm, etc.), YAG laser light (wavelength: 1064 nm), KrF excimer laser light (wavelength: 248 nm), ArF Excimer laser light (wavelength: 193 nm), F2 excimer laser light (wavelength: 157 nm), and the like.

In the method for producing a mold according to the first aspect of the invention, in order to form the surface uneven shape with high precision, it is preferable to perform exposure in a state where the above-described pattern is precisely controlled on the photosensitive resin film in the exposure step. In the method for producing a mold according to the first aspect of the invention, in order to accurately expose the pattern on the photosensitive resin film, it is preferable to form the pattern as image data on a computer and to emit laser light from a computer-controlled laser. Laser light is used to depict a pattern based on its image data. In the case of performing laser light drawing, a laser light drawing device for printing can be used. Examples of such a laser light drawing device include Laser Stream FX (developed by Think Laboratory Co., Ltd.).

Fig. 18(c) schematically shows a state in which the pattern has been exposed on the photosensitive resin film 9. When the photosensitive resin film is formed of a negative-type photosensitive resin, the exposed region 10 undergoes a crosslinking reaction of the resin by exposure, and the solubility with respect to a developing solution to be described later is lowered. Thus, in the developing step, the unexposed area 11 is dissolved by the developer, and only the exposed area 10 remains on the surface of the substrate to become a mask. On the other hand, when the photosensitive resin film is formed from the positive photosensitive resin, the exposed region 10 is exposed, the resin bond is cut, and the solubility with respect to the developer described later increases. Thus, in the developing step, the exposed region 10 is dissolved by the developer, and only the unexposed region 11 remains on the surface of the substrate to become a mask.

[5] Development step

In the next development step, in the case where the photosensitive resin film 9 is a negative-type photosensitive resin, the unexposed region 11 is dissolved by the developer, and only the exposed region 10 remains on the substrate for the mold, and is connected. The first etching step that follows serves as a mask. On the other hand, when the positive photosensitive resin is used for the photosensitive resin film 9, only the exposed region 10 is dissolved by the developer, and the unexposed region 11 remains on the substrate for the mold as the next A mask of an etching step functions.

As the developer used in the developing step, a conventionally known developer can be used. Examples thereof include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium citrate, sodium metasilicate, and aqueous ammonia; and first amines such as ethylamine and n-propylamine, diethylamine, and n-di a second amine such as butylamine; a third amine such as triethylamine or methyldiethylamine; an alcohol amine such as dimethylethanolamine or triethanolamine; tetramethylammonium hydroxide, tetraethylhydroxyammonium or trimethylamine a fourth-order ammonium salt such as hydroxyethylhydroxyammonium; an alkaline aqueous solution such as a cyclic amine such as pyrrole or acridine; an organic solvent such as xylene or toluene; and the like.

The developing method of the developing step is not particularly limited, and methods such as immersion development, spray development, magnetic brush development, and ultrasonic development can be used.

(d) of FIG. 18 is a view schematically showing a state in which the photosensitive resin film 9 is subjected to development processing using a negative-type photosensitive resin. In Fig. 18(c), the unexposed area 11 is dissolved by the developer, and only the exposed area 10 remains on the surface of the substrate to become the mask 12. (e) of FIG. 18 is a view schematically showing a state in which the photosensitive resin film 9 is subjected to development processing using a positive-type photosensitive resin. In Fig. 18(c), the exposed region 10 is dissolved by the developer, and only the unexposed region 11 remains on the surface of the substrate to become the mask 12.

[6] First etching step

In the next first etching step, after the above-described development step, the photosensitive resin film remaining on the surface of the substrate for a mold is used as a mask, and the substrate for the mold of the unmasked portion is mainly used. Etching.

Fig. 19 is a view schematically showing a preferred example of the latter half of the method for manufacturing the mold of the first invention. Fig. 19(a) schematically shows a state in which the mold substrate 7 for the maskless region 13 is mainly etched by the first etching step. The substrate 7 for the mold of the lower portion of the mask 12 is not etched from the surface of the substrate for the mold, but etching is performed from the unmasked region 13 as the etching progresses. Thus, in the vicinity of the boundary between the mask 12 and the maskless region 13, the substrate 7 for the mold of the lower portion of the mask 12 is also etched. Hereinafter, in the vicinity of the boundary between the mask 12 and the maskless region 13, the case where the mold substrate 7 at the lower portion of the mask 12 is also etched is referred to as lateral etching.

The etching treatment in the first etching step is usually performed by using iron chloride (FeCl ₃ ) liquid, copper chloride (CuCl ₂ ) liquid, alkaline etching liquid (Cu(NH ₃ ) ₄ Cl ₂ ), or the like by etching the metal surface. However, it is also possible to use a strong acid such as hydrochloric acid or sulfuric acid, or a reverse electrolytic etching which is carried out by applying a potential opposite to that at the time of electrolytic plating. The concave shape formed by the base material for a mold when the etching treatment is performed differs depending on the type of the base metal, the type of the photosensitive resin film, the etching method, and the like. Therefore, the shape cannot be generalized, but the etching amount is 10 μm or less. In this case, the metal surface that is in contact with the etching liquid is etched substantially in the same direction. The amount of etching referred to herein is the thickness of the substrate which is reduced by etching.

The etching amount of the first etching step is preferably from 1 to 50 μm, more preferably from 2 to 10 μm. When the etching amount is less than 1 μm, the uneven shape is hardly formed on the metal surface, and the mold is substantially flat, so that the anti-glare property is not exhibited. Further, when the etching amount exceeds 50 μm, the difference in height of the uneven shape formed on the metal surface increases, and the anti-glare film formed using the obtained mold may be discolored, which is not preferable. The etching process in the first etching step may be performed by one etching process, or may be performed by dividing the etching process into two or more. Here, when the etching treatment is performed in two or more steps, the total amount of etching of the second or more etching treatment is preferably from 1 to 50 μm.

[7] Photosensitive resin film peeling step

In the next photosensitive resin film peeling step, the remaining photosensitive resin film used as a mask in the first etching step is completely dissolved and removed. In the photosensitive resin film peeling step, the photosensitive resin film is dissolved using a peeling liquid. As the peeling liquid, the same liquid as the above-mentioned developing solution can be used, and the pH, temperature, concentration, immersion time, and the like can be changed, and when the negative-type photosensitive resin film is used, the exposed portion can be used. In the case of the photosensitive resin film, the photosensitive resin film in the non-exposed portion is completely dissolved and removed. The peeling method of the photosensitive resin film peeling step is not particularly limited, and methods such as immersion development, spray development, magnetic brush development, and ultrasonic development can be used.

(b) of FIG. 19 is a view schematically showing a state in which the photosensitive resin film used as a mask in the first etching step is completely dissolved and removed by the photosensitive resin film peeling step. The first surface uneven shape 15 is formed on the surface of the substrate for a mold by the mask 12 of the photosensitive resin film and etching.

[8] Second etching step

In the second etching step, the first surface uneven shape 15 formed by the first etching step is used to passivate the photosensitive resin film as a mask by an etching process. By the second etching treatment, the portion of the first surface uneven shape 15 formed by the first etching treatment is steeply inclined, and the optical characteristics of the anti-glare film produced by the obtained mold are changed in a preferable direction. . Fig. 19(c) shows that the portion of the first surface uneven shape 15 of the substrate 7 for the mold is passivated by the second etching treatment and the portion whose surface is steeply inclined is passivated and the second surface uneven shape 16 having a gentle surface inclination is formed. status.

The etching treatment in the second etching step is also the same as in the first etching step, and generally, a ferric chloride (FeCl ₃ ) solution, a copper chloride (CuCl ₂ ) solution, an alkaline etching solution (Cu(NH ₃ ) ₄ Cl ₂ ), or the like is used. It is carried out by etching the surface, but a strong acid such as hydrochloric acid or sulfuric acid may be used, or reverse electrolytic etching by applying a potential opposite to that at the time of electrolytic plating may be employed. The passivation state of the unevenness after the etching treatment is different depending on the type of the underlying metal, the etching method, and the size and depth of the unevenness obtained by the first etching step. Therefore, the passivation state cannot be generalized, but the control passivation state is the largest. The factor is the amount of etching. The amount of etching referred to herein is also the thickness of the substrate which is reduced by etching as in the first etching step. When the etching amount is small, the effect of passivating the surface shape of the unevenness obtained by the first etching step is insufficient, and the optical characteristics of the antiglare film obtained by transferring the uneven shape to the transparent film are not so good. On the other hand, when the etching amount is large, the uneven shape is almost eliminated, and the mold is substantially flat, so that the anti-glare property is not exhibited. Therefore, the etching amount is preferably in the range of 1 to 50 μm, more preferably in the range of 4 to 20 μm. The etching treatment in the second etching step may be performed by one etching treatment as in the first etching step, or may be performed by dividing the etching treatment into two or more. Here, when the etching treatment is performed in two or more steps, the total amount of etching of the second or more etching treatment is preferably from 1 to 50 μm.

[9] Second plating step

Next, by performing chrome plating, the second surface relief shape 16 is passivated and the mold surface is protected. Fig. 19(d) shows a state in which the chromium plating layer 17 is formed on the second surface uneven shape 16 formed by the etching treatment in the second etching step as described above, and the surface 18 of the chromium plating layer is passivated.

In the first aspect of the invention, chrome plating having a gloss, a high hardness, a small friction coefficient, and imparting good mold release property is used for surfaces such as a flat plate and a roll. The type of chrome plating is not particularly limited, but chrome plating which exhibits good gloss such as so-called gloss chrome plating and decorative chrome plating is preferably used. The chrome plating is usually carried out by electrolysis, and as its plating solution, an aqueous solution containing chromium trioxide (CrO ₃ ) and a small amount of sulfuric acid is used. The thickness of the chrome plating can be controlled by adjusting the current density and the electrolysis time.

Further, in the second plating step, plating other than chrome plating is not preferable. The reason is that in the plating other than chromium, the hardness and the abrasion resistance are low, the durability of the mold is lowered, and the unevenness is worn or the mold is damaged during use. In the antiglare film obtained from such a mold, it is difficult to obtain a sufficient antiglare function, and the possibility of occurrence of defects on the film is also high.

In addition, the grinding of the surface after plating is still not preferable in the first invention. The reason is as follows: by polishing, a flat portion is generated on the outermost surface, so that optical characteristics may be deteriorated, and since the shape control factor is increased, shape control with good reproducibility is difficult.

As described above, in the first aspect of the invention, it is preferable to use the chrome-plated surface as the uneven surface of the mold without polishing the surface after the chrome plating is performed. The reason is that by chrome plating the surface on which the fine surface uneven shape is formed, a mold in which the uneven shape is passivated and the surface hardness thereof is improved is obtained. The passivation state of the concavities and convexities at this time differs depending on the type of the base metal, the size and depth of the concavities and convexities obtained from the first etching step, and the type and thickness of the plating, and therefore cannot be generalized, but the control passivation state is the largest. The factor is still the plating thickness. When the thickness of the chrome plating is thin, the effect of passivating the surface shape of the unevenness obtained before the chrome plating is insufficient, and the optical characteristics of the antiglare film obtained by transferring the uneven shape to the transparent film are not so good. On the other hand, when the plating thickness is too thick, the productivity is deteriorated, and a projection-like plating defect called a nodule also occurs, which is not preferable. Therefore, the thickness of the chrome plating is preferably in the range of 1 to 10 μm, more preferably in the range of 3 to 6 μm.

The chrome plating layer formed in the second plating step is preferably formed to have a Vickers hardness of 800 or more, more preferably 1,000 or more. When the Vickers hardness of the chrome plating layer is less than 800, the durability of the mold is lowered, and the hardness is lowered by the chrome plating because the plating solution is abnormally formed in the plating solution composition, the electrolysis condition, and the like. The possibility is high, and the possibility of adversely affecting the occurrence of defects is also high.

[Examples]

Hereinafter, the first invention will be further described in detail by way of examples, but the first invention is not limited to the embodiments. In the examples, the % and the parts indicating the content or the amount used are the weight basis unless otherwise specified. Moreover, the evaluation method of the mold or the anti-glare film of the following examples is as follows.

[1] Measurement of surface shape of anti-glare film

(measurement of the elevation of the surface)

The elevation of the surface of the anti-glare film was measured using a three-dimensional microscope PLμ2300 (developed by Sensofar Co.). In order to prevent the sample from being warped, an optically transparent adhesive is used, and the surface is attached to the glass substrate so that the uneven surface becomes a surface, and is used for measurement. At the time of measurement, the magnification of the objective lens was set to 10 times for measurement. The horizontal resolutions Δx and Δy are both 1.66 μm, and the measurement area is 1270 μm × 950 μm.

(power spectrum of complex amplitude)

From the central portion of the measurement data obtained above, 512 × 512 (measured area, 850 μm × 850 μm) data were extracted, and the elevation of the fine uneven surface of the anti-glare film was set as a two-dimensional function h(x, y). Find out. From the obtained two-dimensional function h(x, y), the complex amplitude is calculated as a two-dimensional function ψ(x, y). The wavelength λ at the time of calculating the complex amplitude was set to 550 nm. The two-dimensional function ψ(x, y) is subjected to discrete Fourier transform to obtain a two-dimensional function Ψ(f _x , f _y ). The two-dimensional function Ψ(f _x ,f _y ) is squared to calculate the two-dimensional function 二维² (f _x ,f _y ) of the two-dimensional power spectrum, and then the function of the distance f from the origin is calculated, that is, the one-dimensional power spectrum The one-dimensional function Ψ ² (f). By linearly interpolating the one-dimensional function Ψ ² (f), a discrete function every 0.008 μm ^-1 is obtained. From the discrete function of every 0.008 μm ^-1 , that is, the second derivative of Ψ ² (f), the inflection point of the one-dimensional power spectrum of the complex amplitude is calculated.

(inclination of the fine concave surface)

Based on the measurement data obtained above, a histogram of the inclination angle of the uneven surface is calculated based on the above-described algorithm, and the distribution of each inclination angle is obtained from the histogram, and the ratio of the surface having the inclination angle of 5 or more is calculated.

(surface roughness parameter of fine uneven surface)

The surface roughness parameter of the anti-glare film was measured using a surface roughness measuring instrument Surftest SJ-301 developed by Mitsuyo Co., Ltd. based on JIS B 0601. In order to prevent warpage of the sample, an optically transparent adhesive is used, and the surface of the uneven surface is bonded to the glass substrate to be used for measurement.

[2] Measurement of optical properties of anti-glare film

(haze)

The measurement of the full haze of the anti-glare film is as follows. The anti-glare film is bonded to the glass substrate by using an optically transparent adhesive on the surface opposite to the anti-glare layer forming surface, and the obtained glass substrate is bonded to the glass substrate. The anti-glare film was used to measure light from the side of the glass substrate, and was measured using a hazemeter "HM-150" type developed by Murakami Color Research Institute, JIS K 7136. In addition, the measurement of the internal haze was carried out by attaching a triacetyl cellulose film having a haze of substantially 0 to the uneven surface of the antiglare layer with glycerin, and measuring again based on JIS K 7136. The surface haze is calculated based on the above formula (12).

(through vividness)

The transmission sensibility of the anti-glare film was measured using a mapping measuring instrument "ICM-IDP" developed by Sugatest Co., Ltd. based on JIS K 7105. In this case, in order to prevent the warpage of the sample, an optically transparent adhesive is applied to the glass substrate so that the fine uneven surface of the glare layer becomes a surface, and is used for measurement. In this state, light was incident from the glass side, and measurement was performed. The measured value here is a total value of values measured using four types of optical combs having a width of the dark portion and the bright portion of 0.125 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively. The maximum value of the transmission sharpness at this time is 400%.

(reflective sharpness)

The reflectance of the anti-glare film was measured using a mapping measuring instrument "ICM-1DP" developed by Sugatest Co., Ltd. based on JIS K 7105. In this case, in order to prevent the warpage of the sample, an optically transparent adhesive is applied to the black acrylic substrate so that the fine uneven surface of the glare layer becomes a surface, and is used for measurement. In this state, light was incident at 45° from the uneven surface side, and measurement was performed. The measured value here is a total value of values measured using four types of optical combs having a width of the dark portion and the bright portion of 0.5 mm, 1.0 mm, and 2.0 mm, respectively. The maximum value of the reflection sharpness at this time is 300%.

[3] Measurement of mechanical properties of anti-glare film

(pencil hardness)

The pencil hardness of the antiglare film was measured by the method specified in JIS K5600-5-4. Specifically, an electric pencil scratch hardness tester (developed by Yasuda Precision Instruments Co., Ltd.) based on this specification was used, and measurement was performed with a load of 500 g.

[4] Evaluation of anti-glare properties of anti-glare film

(Visual evaluation of reflection and fading)

In order to prevent reflection from the back surface of the anti-glare film, the anti-glare film is bonded to the black acrylic plate so that the uneven surface becomes the surface, and the inside of the bright room with the fluorescent lamp is visually observed from the uneven surface side. The presence or absence of the fluorescent lamp and the degree of fading were visually evaluated. The reflection and fading were performed in three stages of 1 to 3, respectively, and evaluated by the following criteria.

Reflect

1: No reflection was observed.

2: A slight reflection was observed.

3: Observing the reflection clearly.

fade

1: No fading was observed.

2: A slight fading was observed.

3: Fading was clearly observed.

(evaluation of dizziness)

The glare was evaluated in the following order. That is, first, a photomask having a unit pattern shown in a plan view in Fig. 11 is prepared. In the figure, in the unit 40, a chrome-shielding pattern 41 having a line width of 10 μm and a key shape is formed on a transparent substrate, and a portion where the chrome-shielding pattern 41 is not formed is an opening portion 42. Here, since the size of the cell is 211 μm × 70 μm (vertical × horizontal in the drawing), the size of the opening is 201 μm × 60 μm (vertical × horizontal). Many of the illustrated units are juxtaposed side by side to form a reticle.

Then, as shown in the schematic cross-sectional view of Fig. 12, the chrome-shielding pattern 41 of the mask 43 is placed on the light box 45 so as to be positioned on the upper side, and the anti-glare film 1 is made to have the surface of the anti-glare film 1 by the adhesive. The sample attached to the glass plate 47 is placed on the reticle 43. A light source 46 is disposed in the light box 45. In this state, visual observation was performed at a position 49 of about 30 cm from the sample, whereby the degree of glare was evaluated by seven levels. The first stage is in a state where no dizziness is seen at all, the seventh level is equivalent to the state in which strong dizziness is observed, and the fourth level is a state in which a slight dizziness is observed.

[5] Evaluation of patterns for the manufacture of anti-glare films

The created pattern data is set to binarized image data of two gradation, and the gradation is represented by a two-dimensional discrete function g(x, y). The horizontal resolutions Δx and Δy of the discrete function g(x, y) are both set to 2 μm. A discrete Fourier transform is performed on the obtained two-dimensional function g(x, y) to obtain a two-dimensional function G(f _x , f _y ). Square the two-dimensional function G(f _x , f _y ), calculate the two-dimensional function G ² (f _x , f _y ) of the two-dimensional power spectrum, and then calculate the function of the distance f from the origin, that is, the one-dimensional power spectrum. One-dimensional function G ² (f).

<Example 1>

(Production of mold for manufacturing anti-glare film)

A roller of a Ballard copper plating was prepared on the surface of an aluminum roller (JIS A5056) having a diameter of 200 mm. Ballard copper plating is composed of a copper plating layer/thin silver plating layer/surface copper plating layer, and the thickness of the entire plating layer is set to 200 μm. The copper plating surface is mirror-polished, and a photosensitive resin is applied to the surface of the copper plating after polishing, and dried to form a photosensitive resin film. Next, the following pattern is exposed and developed on the photosensitive resin film by laser light, and the pattern is the pattern shown in FIG. 16 (passing through the pattern having a random luminance distribution and removing 0.035 μm ^-1 or less The low spatial frequency component and the band-pass filter of a high spatial frequency component of 0.15 μm ^-1 or more are formed by repeating the parallel arrangement. Exposure and development of laser light were carried out using Laser Stream FX (developed by Think Laboratory Co., Ltd.). A positive photosensitive resin is used for the photosensitive resin film.

Thereafter, the first etching treatment is performed with a copper chloride solution. The etching amount at this time was set to 3 μm. The photosensitive resin film was removed from the roll after the first etching treatment, and the second etching treatment was performed again with the copper chloride liquid. The etching amount at this time was set to 6 μm. Thereafter, chrome plating was performed to prepare a mold A. At this time, the chrome plating thickness was set to 4 μm.

(Formation of anti-glare film)

Each of the following components was dissolved in ethyl acetate at a solid concentration of 60%, and an ultraviolet curable resin composition A having a refractive index of 1.53 after curing was purchased.

60 parts of pentaerythritol triacrylate

40 parts of multifunctional urethane acrylate

(Reactive product of hexamethylene diisocyanate and pentaerythritol triacrylate) diphenyl (2,4,6-trimethoxybenzylidene) phosphine oxide 5 parts

The ultraviolet curable resin composition A was applied onto a triacetyl cellulose (TAC) film having a thickness of 80 μm so as to have a coating thickness after drying of 7 μm, and dried in a dryer set at 60° C. for three minutes. The dried film is pressed against the uneven surface of the mold A obtained in advance so that the photocurable resin composition layer becomes the mold side by a rubber roller, and is adhered to each other. In this state, light from a high-pressure mercury lamp having a strength of 20 mW/cm ^{2 was} irradiated from the TAC film side to an amount of 200 mJ/cm ² in terms of an h-line conversion, and the photocurable resin composition layer was cured. Thereafter, the TAC film was peeled off from the mold together with the cured resin to prepare a transparent anti-glare film A composed of a laminate of a cured resin having irregularities on the surface and a TAC film.

<Example 2>

An anti-glare film B was produced in the same manner as in Example 1 except that the mold B was produced in the same manner as in Example 1 except that the etching amount of the second etching treatment was changed to 8 μm.

<Example 3>

An anti-glare film C was produced in the same manner as in Example 1 except that the mold C was used in the same manner as in Example 1 except that the etching amount of the second etching treatment was changed to 10 μm.

<Example 4>

The pattern is exposed on the photosensitive resin film by laser light, and the pattern is a pattern shown in FIG. 20 (passing a low spatial frequency component of 0.033 μm ^-1 or less from a pattern having a random luminance distribution. It is prepared by repeating the parallel arrangement with a band-pass filter having a high spatial frequency component of 0.15 μm ^-1 or more, except that the etching amount of the first etching treatment is set to 4 μm, and the etching amount of the second etching treatment is set to 8 μm. In the same manner as in Example 1, except that the mold D was used, an anti-glare film D was produced in the same manner as in Example 1 except that the mold D was used.

<Comparative column 1>

The pattern is exposed on the photosensitive resin film by laser light, and the pattern is a pattern shown in Fig. 21 (passing a low spatial frequency component of 0.023 μm ^-1 or less from a pattern having a random luminance distribution. It is prepared by repeating the parallel arrangement with a band-pass filter having a high spatial frequency component of 0.15 μm ^-1 or more, except that the etching amount of the first etching treatment is set to 4 μm, and the etching amount of the second etching treatment is set to 10 μm. In the same manner as in Example 4, a mold E was produced, and an anti-glare film E was produced in the same manner as in Example 1 except that the mold E was used.

<Comparative Example 2>

The pattern is exposed on the photosensitive resin film by laser light, and the pattern is a pattern shown in Fig. 22 (passing a low spatial frequency component of 0.043 μm ^-1 or less from a pattern having a random luminance distribution. A mold F was produced in the same manner as in Example 3 except that the mold F was used in the same manner as in Example 3 except that the band-pass filter having a high spatial frequency component of 0.15 μm ^-1 or more was used in the same manner. In the same manner, an anti-glare film F was produced.

<Comparative Example 3>

The surface of an aluminum roller (JIS A5056) having a diameter of 300 mm was mirror-polished, and a sandblasting device (developed by Fujifilm Co., Ltd.) was used. The surface of the polished aluminum was pressed at a pressure of 0.1 MPa (gauge pressure, the same below). ), the amount of beads used is 8 g/cm ² (the surface area of the roll is on average per 1 cm ² , the same applies hereinafter), and the zirconia beads TZ-SX-17 (developed by Tosoh Co., Ltd., average particle diameter: 20 μm), Thereby, the surface is covered with irregularities. The obtained aluminum roll having irregularities was subjected to electroless nickel plating to prepare a mold G. At this time, the thickness of the electroless nickel plating was set to 15 μm. An anti-glare film G was produced in the same manner as in Example 1 except that the obtained mold G was used.

The results are shown in Table 1. Further, Fig. 17 shows a one-dimensional power spectrum obtained from the pattern used in the production of the anti-glare films A to C; and Fig. 23 shows a one-dimensional power spectrum G obtained from the pattern used in the production of the anti-glare films D to F. ² (f). As can be seen from FIGS. 17 and 23, the one-dimensional power spectrum of the pattern used in the production of the anti-glare films A to D does not have a maximum value at a spatial frequency of more than 0 μm ^-1 and 0.04 μm ^-1 or less, and is larger than 0.04 μm. ^-1 and 0.08 Pμm ^-1 or less have a maximum value. On the other hand, it is understood that the pattern used in the production of the anti-glare film E has a maximum value when it is larger than 0 μm ^-1 and 0.04 μm ^-1 or less, and the pattern used in the production of the anti-glare film F is more than 0.04 μm ^-1 and 0.08 μm. There is no maximum value when ^-1 or less. Figure 24 shows the second-order derivative function d ² Ψ ² (f)/df ² of the one-dimensional power spectrum of the complex amplitude calculated from the elevation of the anti-glare films A to D, and Fig. 25 shows the anti-glare film E to G The second-order derivative function d ² Ψ ² (f)/df ² of the one-dimensional power spectrum of the complex amplitude calculated by the elevation.

As can be seen from Figs. 24 and 25, the power spectrum of the complex amplitude calculated from the elevation of the anti-glare films A to D and F has two refractions in the range of a spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less. However, the one-dimensional power spectrum of the complex amplitude calculated from the elevation of the anti-glare films E and G is not a power spectrum having two inflection points in the range of a spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less.

As is clear from the results shown in Table 1, all of the anti-glare films A to D which satisfy the requirements of the first aspect of the present invention do not substantially glare, and exhibit sufficient anti-glare properties, and substantially no fading occurs. Further, when disposed in the image display device, the contrast is not lowered. On the other hand, as shown in Fig. 25, the anti-glare films E and G are not one-dimensional power spectrum of the complex amplitude calculated from the elevation, and have two inverses in the range of the spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less. The anti-glare film of the vertices shows a tendency to cause glare. The anti-glare film F although the one-dimensional power spectrum of the complex amplitude satisfies the requirements of the first invention, the surface haze does not satisfy the requirements of the first invention, and thus reflection is observed.

[Symbol Description]

1 anti-glare film

2 Bumps formed on the surface of the film

3 film projection surface

5 The main normal direction of the film

6 normal of local location

6a to 6d polyhedral normal vector

7 mold substrate

8 Surface of the substrate ground by the grinding step

9 photosensitive resin film

10 exposed areas

11 unexposed area

12 mask

13 unmasked area

15 First surface uneven shape (concavo-convex shape of the surface of the substrate for the mold after the first etching step)

16 second surface uneven shape (concave-convex shape of the surface of the substrate for the mold after the second etching step)

17 chrome layer

18 chrome surface

20 elevation datum

21 highest elevation surface

40 reticle unit

41 reticle chrome shade pattern

42 the opening of the mask

43 mask

45 light box

46 light source

47 glass plate

49 flashing observation position

50 diffuser

[An embodiment of the second invention]

<Liquid crystal display device>

The liquid crystal display device of the present invention includes a liquid crystal cell in which liquid crystal is sealed between a pair of mutually parallel cassette substrates, and the liquid crystal is oriented in a substantially vertical direction with respect to the cassette substrate in the vicinity of the cassette substrate in a voltage-free application state; The side polarizing film is disposed on the recognition side of the liquid crystal cell; the back side polarizing film is disposed on the opposite side; and at least one retardation film is disposed between the back side polarizing film and the liquid crystal cell and/or the front side polarized light Between the film and the liquid crystal cell; the anti-glare film includes a transparent support and an anti-glare layer, and the anti-glare layer is formed on the transparent support and has a fine uneven surface having fine irregularities on the opposite side of the transparent support. Moreover, the anti-glare film is disposed on the opposite side of the surface of the front-side polarizing film facing the liquid crystal cell so that the anti-glare layer is the most recognizable side.

The liquid crystal display device of the second aspect of the invention has a feature in the shape of the fine uneven surface of the anti-glare film (anti-glare layer). The anti-glare film is the same as the first invention.

27 to 32 show a specific example of the liquid crystal display device of the second invention. The liquid crystal display device shown in FIGS. 27 to 32 includes a liquid crystal cell 110 and a pair of polarizing films (front side polarizing film 120 and back side polarizing film 121) disposed so as to sandwich the liquid crystal cell 110, and arrangement The retardation films 130 and 131 between the back side polarizing film 121 and the liquid crystal cell 110 and/or between the front side polarizing film 120 and the liquid crystal cell 110. Further, on the side opposite to the surface of the front side polarizing film 120 opposed to the liquid crystal cell 110, the antiglare film 1 composed of the transparent support 101 and the antiglare layer 100 is laminated so that the antiglare layer 100 is the most recognizable side. .

As described above, the liquid crystal display device of the second aspect of the invention includes a liquid crystal cell, a pair of polarizing films (front side polarizing film and back side polarizing film), at least one retardation film, and an anti-glare film. However, the transparent protective film which will be described later is an arbitrary structure provided between them as needed. That is, the combination of the positions at which the transparent protective film is provided is not particularly limited, and a liquid crystal display device in which the transparent protective film is not provided at all is also included in the second invention. Next, various configurations of the liquid crystal display device of the second aspect of the present invention will be described with reference to Figs. 27 to 32.

In the liquid crystal display device shown in Fig. 27, the first retardation film 130 is disposed between the cell substrate 111 and the front side polarizing film 120. Further, a second retardation film 131 is disposed between the cell substrate 112 on the opposite side of the first retardation film 130 and the back side polarizing film 121. Moreover, the anti-glare film 1 is disposed on the surface on the side opposite to the side facing the liquid crystal cell 110 of the front side polarizing film 120, that is, on the display surface (recognition) side. The anti-glare film 1 is composed of a transparent support 101 and an anti-glare layer 100. The anti-glare layer 100 is formed on the transparent support and has a fine uneven surface having fine irregularities on the opposite side of the transparent support. Further, the anti-glare film 1 is disposed such that the anti-glare layer 100 is the most recognizable side.

In the liquid crystal display device shown in Fig. 27, retardation films 130 and 131 are provided on both sides (front side and back side) of the liquid crystal cell 110. However, in the liquid crystal display device of the second aspect of the invention, a retardation film may be provided on both sides of the liquid crystal cell, or a retardation film may be provided only on the front side or the back side. Fig. 28 shows a configuration in which a retardation film is provided only on the front side. In Fig. 28, the phase difference film 131 of Fig. 27 is replaced with a transparent protective film 104.

Further, in the liquid crystal display device shown in Fig. 27, the transparent protective film 102 is laminated on the back side of the back side polarizing film 121. In the liquid crystal display device of the second aspect of the invention, the transparent protective film is not necessarily required. However, as shown in Figs. 27 to 32, it is preferable to arrange a transparent protective film on at least the back side of the back side polarizing film.

In the liquid crystal display device shown in Fig. 29, a transparent protective film 103 is provided between the front side polarizing film 120 and the retardation film 130, and is different from the liquid crystal display device shown in Fig. 27 in this point. Further, the first retardation film 130 of the liquid crystal display device shown in Fig. 27 can also function as a transparent protective film.

The liquid crystal display device shown in Fig. 30 has a configuration in which a transparent protective film 104 is provided between the back side polarizing film 121 and the retardation film 131 as compared with the liquid crystal display device shown in Fig. 29.

The liquid crystal display device shown in Fig. 31 does not have a retardation film on the front side of the liquid crystal cell 110, and is different from the liquid crystal display device shown in Fig. 30 in this point. On the other hand, the liquid crystal display device shown in Fig. 32 does not have a retardation film on the back side of the liquid crystal cell 110, and is different from the liquid crystal display device shown in Fig. 30 in this point.

For example, as shown in FIG. 30 and FIG. 31, when the retardation film 131 is disposed on the back side of the liquid crystal cell 110, the retardation film 131 functions to protect the transparent protective film of the back side polarizing film 121, and can be omitted. Transparent protective film 104. In this case, it is also preferable to provide the transparent protective film 102 on the back side of the back side polarizing film 121.

The liquid crystal display device according to the second aspect of the present invention is not limited to the configuration shown in Figs. 27 to 32, and includes the configuration in which the transparent protective film 104 is changed to a retardation film in Fig. 32 and the structures in Figs. 27 to 32. A configuration in which a transparent protective film is provided between the retardation films 130 and 131 and the liquid crystal cell 110 also includes a configuration in which a transparent protective film is not used.

A backlight (not shown) for supplying light to the liquid crystal cell 110 is usually provided on the more back surface side of the back side polarizing film 121 (the back side of the transparent film 102).

(liquid crystal cell)

The liquid crystal cell 110 has two block substrates 111 and 112 which are parallel to each other, and a liquid crystal layer 115 in which liquid crystal (clamp-hold) is sealed between the two cassette substrates, and is provided on the opposite faces of the cassette substrates 111 and 112, respectively. Electrodes 113, 114. Further, the liquid crystal of the liquid crystal layer 115 of the liquid crystal cell 110 is at least in the vicinity of the cassette substrates 111, 112 (generally from one cassette substrate 111 to the other cassette substrate 112) in a voltage-free application state, and is substantially perpendicular to the cassette substrate. Orientation in the direction. Thus, the liquid crystal cell 110 which is targeted in the second invention is a so-called liquid crystal cell of a vertical alignment mode.

(polarized film)

The front side polarizing film 120 and the back side polarizing film 121 may be of a type that transmits linearly polarized light that vibrates in one direction perpendicular to each other in the film surface and absorbs linearly polarized light that vibrates in the other direction, and is generally used as a polarizing film or A film known as a polarizing plate. Specifically, for example, a polyvinyl alcohol-based polarizing film in which a polyvinyl alcohol film is subjected to uniaxial extention and high dichroism pigment dyeing and also boric acid cross-linking can be used. . Further, an iodine-based polarizer using iodine as a high dichroic dye and a dye-based polarizer using a dichroic organic dye as a high dichroic dye can be used. Further, a polarizing plate in which a transparent protective film is laminated on one or both sides of such a polarizing film may be used for the liquid crystal display device of the second aspect of the invention.

(phase difference film)

The in-plane retardation value R ₀ of the first retardation film 130 and the second retardation film 131 is 50 nm or more and 80 nm or less, and the thickness direction retardation R _{th is} preferably 120 nm or more and 250 nm or less. When the in-plane retardation value R ₀ and the thickness direction retardation value R _{th of the} first retardation film 130 and the second retardation film 131 are outside these ranges, the viewing angle characteristics are degraded, which is not preferable. Further, for the same reason, it is more preferable that the in-plane retardation value R ₀ is 55 nm or more and 80 nm or less, and the thickness direction retardation value R _th is 124 nm or more and 250 nm or less.

Here, the refractive index of the in-plane slow axis direction of the film (the direction in which the refractive index is maximum in the film plane) is n _x , and the in-plane axis direction of the film (in-plane fast axis direction) (the direction perpendicular to the direction of the slow axis, that is, the direction in which the refractive index is the smallest), the refractive index is n _y , the refractive index in the thickness direction of the film is n _z , and the thickness of the film is set. In the case of d, the in-plane phase difference value R ₀ and the thickness direction phase difference value R _th are defined by the following equations (13) and (14), respectively.

R ₀ =(n _x -n _y )×d ‧‧‧(13)

R _th =[(n _x +n _y )/2-n _z ]×d ‧‧‧(14)

The retardation axes of the retardation films 130 and 131 are arranged in a substantially parallel relationship or a substantially perpendicular relationship with the transmission axis of the adjacent polarizing film 120 or 121. The term "substantially" when the retardation axes of the retardation films 130 and 131 and the transmission axis of the polarizing film adjacent thereto are substantially parallel or substantially perpendicular means that although it is desired to be completely parallel or perpendicular, Practically, it is allowed to be about ±5° around its angle. The retardation axes of the retardation films 130 and 131 and the transmission axis of the polarizing film adjacent thereto are preferably arranged in a substantially parallel relationship.

The retardation film having such characteristics can be obtained by subjecting a film composed of a transparent resin having a positive refractive index anisotropic property to uniaxial or biaxial stretching under appropriate conditions. As the transparent resin having a positive refractive index and an anisotropy, a cellulose resin typified by a deuterated cellulose such as triacetyl cellulose, a cyclic olefin resin, or a polycarbonate can be used. Here, the cyclic olefin resin is a resin in which a cyclic olefin such as norbornene or dimethylene sulfoxide is a monomer, and is commercially available as "Zeonor Film" (trade name: developed by Optes). . In addition, examples of the triacetonitrile cellulose film include "VA-TAC film" (trade name: Konic minolta) and "VA-TAC film" (trade name: Fujifilm). In the above-mentioned transparent resin, since the photoelastic coefficient is small and the occurrence of uneven in-plane characteristics due to thermal deformation under the use conditions is small, triacetyl cellulose and a cyclic olefin resin are preferably used.

The first retardation film 130 or the second retardation film 131 and the liquid crystal cell 110 are usually adhered via a binder. As the binder, a binder excellent in transparency such as acrylic is usually used. Further, the first retardation film 130 and the second retardation film 131 having the above characteristics may be disposed to be replaced with each other.

(transparent protective film)

The transparent protective film is not particularly limited as long as it is a transparent film, and various known transparent protective films used for liquid crystal display devices and the like can be used, and examples thereof include a triacetyl cellulose (TAC) film and an acrylic resin. A film, a polyethylene terephthalate film, an unstretched norbornene film, or the like.

[Examples]

Hereinafter, the second invention will be further described in detail by way of examples, but the second invention is not limited to the embodiments. In the examples, the % and the parts indicating the content or the amount used are based on weight unless otherwise specified. Moreover, the evaluation method of the mold or the anti-glare film of the following examples is as follows.

[1] Measurement of surface shape of anti-glare film

(measurement of the elevation of the surface)

The elevation of the surface of the anti-glare film was measured using a three-dimensional microscope PLμ2300 (developed by Sensofar Co.). In order to prevent the sample from being warped, an optically transparent adhesive is used, and the surface is attached to the glass substrate so that the uneven surface becomes a surface, and is used for measurement. At the time of measurement, the magnification of the objective lens was set to 10 times for measurement. The horizontal resolutions Δx and Δy are both 1.66 μm, and the measurement area is 1270 μm × 950 μm.

(power spectrum of complex amplitude)

From the central portion of the measurement data obtained above, 512 × 512 (measured area, 850 μm × 850 μm) data were extracted, and the elevation of the fine uneven surface of the anti-glare film was set as a two-dimensional function h(x, y). Find out. From the obtained two-dimensional function h(x, y), the complex amplitude is calculated as a two-dimensional function ψ(x, y). The wavelength λ at the time of calculating the complex amplitude was set to 550 nm. The two-dimensional function ψ(x, y) is subjected to discrete Fourier transform to obtain a two-dimensional function Ψ(f _x , f _y ). The two-dimensional function Ψ(f _x ,f _y ) is squared to calculate the two-dimensional function 二维² (f _x ,f _y ) of the two-dimensional power spectrum, and then the function of the distance f from the origin is calculated, that is, the one-dimensional power spectrum The one-dimensional function Ψ ² (f). By linearly interpolating the one-dimensional function Ψ ² (f), a discrete function every 0.008 μm ^-1 is formed. From the discrete function of every 0.008 μm ^-1 , that is, the second derivative of Ψ ² (f), the inflection point of the one-dimensional power spectrum of the complex amplitude is calculated.

(inclination of the fine concave surface)

Based on the measurement data obtained above, a histogram of the inclination angle of the uneven surface is calculated based on the above-described algorithm, and the distribution of each inclination angle is obtained from the histogram, and the ratio of the surface having the inclination angle of 5 or more is calculated.

(surface roughness parameter of fine uneven surface)

The surface roughness parameter of the anti-glare film was measured using a surface roughness measuring instrument Surftest SJ-301 developed by Mitsuyo Co., Ltd. based on JIS B 0601. In order to prevent warpage of the sample, an optically transparent adhesive is used, and the surface of the uneven surface is bonded to the glass substrate to be used for measurement.

[2] Measurement of optical properties of anti-glare film

(haze)

The measurement of the full haze of the anti-glare film is as follows. The anti-glare film is bonded to the glass substrate by using an optically transparent adhesive on the surface opposite to the anti-glare layer forming surface, and the obtained glass substrate is bonded to the glass substrate. The anti-glare film was used to measure light from the glass substrate side, and was measured using a haze meter "HM-150" type developed by Murakami Color Technology Research Institute, JIS K 7136. In addition, the measurement of the internal haze was carried out by attaching a triacetyl cellulose film having a haze of substantially 0 to the uneven surface of the antiglare layer with glycerin, and measuring again based on JIS K 7136. The surface haze is calculated based on the above formula (12).

(through vividness)

The transmission sensibility of the anti-glare film was measured using a mapping measuring instrument "ICM-IDP" developed by Sugatest Co., Ltd. based on JIS K 7105. In this case, in order to prevent the warpage of the sample, an optically transparent adhesive is used, and the fine concavo-convex shape surface of the glare layer is bonded to the glass substrate so as to be a surface, and is used for measurement. In this state, light was incident from the glass side, and measurement was performed. The measured value here is a total value obtained by measuring four optical combs having a width of the dark portion and the bright portion of 0.125 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively. The maximum value of the transmission sharpness at this time is 400%.

(reflective sharpness)

The reflectance of the anti-glare film was measured using a mapping measuring instrument "ICM-1DP" developed by Sugatest Co., Ltd. based on JIS K 7105. In this case, in order to prevent the warpage of the sample, an optically transparent adhesive is used, and the fine embossed surface of the glare layer is bonded to the black acrylic substrate so as to prevent the surface of the glare layer from being applied to the black acrylic substrate. In this state, light was incident at 45° from the uneven surface side, and measurement was performed. The measured value here is a total value obtained by measuring four kinds of optical combs having a width of the dark portion and the bright portion of 0.5 mm, 1.0 mm, and 2.0 mm, respectively. The maximum value of the reflection sharpness at this time is 300%.

[3] Measurement of mechanical properties of anti-glare film

(pencil hardness)

The pencil hardness of the antiglare film was measured by the method specified in JIS K5600-5-4. Specifically, an electric pencil scratch hardness tester (developed by Yasuda Precision Instruments Co., Ltd.) based on this specification was used, and measurement was performed with a load of 500 g.

[4] Evaluation of liquid crystal display devices

(contrast)

In the dark room, the backlight of the liquid crystal display device was turned on, and the brightness of the liquid crystal display device in the black display state and the white display state was measured using a brightness meter BM5A type (developed by Topcon Co., Ltd.), and the contrast was calculated. Here, the contrast is expressed by the ratio of the brightness of the white display state to the brightness of the black display state.

(reflection, fading, dizziness)

The contrast evaluation system described above was moved to a bright room, and as a black display state, the reflection state and fading were visually observed. Next, in the bright room, as a white display state, visual observation was also performed regarding the flare. The evaluation criteria relating to the state of reflection, fading, and glare are as follows.

(a) reflected

1: No reflection was observed.

2: A slight reflection was observed.

3: Observing the reflection clearly.

(b) Fading

1: No fading was observed.

2: A slight fading was observed.

3: Fading was clearly observed.

(c) flashing

1, can not see the dizziness.

2. A slight dizziness was observed.

3. Strong dizziness was observed.

[5] Evaluation of patterns for the manufacture of anti-glare films

The created pattern data is set to binarized image data of two gradation, and the gradation is represented by a two-dimensional discrete function g(x, y). The horizontal resolutions Δx and Δy of the discrete function g(x, y) are both set to 2 μm. A discrete Fourier transform is performed on the obtained two-dimensional function g(x, y) to obtain a two-dimensional function G(f _x , f _y ). Square the two-dimensional function G(f _x , f _y ), calculate the two-dimensional function G ² (f _x , f _y ) of the two-dimensional power spectrum, and then calculate the function of the distance f from the origin, that is, the one-dimensional power spectrum. One-dimensional function G ² (f).

<Example 21>

(A) Production of polarizing film

A polyvinyl alcohol film having an average polymerization degree of about 2400, a degree of saponification of 99.9 mol% or more and a thickness of 75 μm was immersed in pure water at 30 ° C, and then immersed in a mass ratio of iodine/potassium iodide/water at 30 ° C. An aqueous solution of 0.02/2/100. Thereafter, it was immersed in an aqueous solution having a mass ratio of potassium iodide/boric acid/water of 12/5/100. Subsequently, it was washed with pure water at 8 ° C, and then dried at 65 ° C to obtain a polarizing film which was adsorbed by iodine orientation on polyvinyl alcohol. The stretching was mainly carried out in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio was 5.3 times.

(B) Production of a mold for manufacturing an anti-glare film

A roller of a Ballard copper plating was prepared on the surface of an aluminum roller (JIS A5056) having a diameter of 200 mm. The Ballard copper plating is composed of a copper plating layer/thin silver plating layer/surface copper plating layer, and the thickness of the entire plating layer is set to be about 200 μm. The copper plating surface is mirror-polished, and a photosensitive resin is applied to the surface of the copper plating after polishing, and dried to form a photosensitive resin film. Next, the following pattern is exposed and developed on the photosensitive resin film by laser light, and the pattern is the pattern shown in FIG. 16 (passing through the pattern having a random luminance distribution and removing 0.035 μm ^-1 or less The low spatial frequency component and the band-pass filter of a high spatial frequency component of 0.15 μm ^-1 or more are formed by repeating the parallel arrangement. Exposure and development of laser light were carried out by Laser Stream FX (developed by Think Laboratory, Inc.). A positive photosensitive resin is used for the photosensitive resin film.

Thereafter, the first etching treatment is performed with a copper chloride solution. The etching amount at this time was set to 3 μm. The photosensitive resin film was removed from the roller after the first etching treatment, and the second etching treatment was performed again with the copper chloride solution. The etching amount at this time was set to 10 μm. Thereafter, chrome plating was performed to prepare a mold A. At this time, the chrome plating thickness was set to 4 μm.

(C) (production of anti-glare film)

Each of the following components was dissolved in ethyl acetate at a solid concentration of 60%, and an ultraviolet curable resin composition A having a refractive index of 1.53 after curing was purchased.

60 parts of pentaerythritol triacrylate

40 parts of multifunctional urethane acrylate

(Reactive product of hexamethylene diisocyanate and pentaerythritol triacrylate) diphenyl (2,4,6-trimethoxybenzylidene) phosphine oxide 5 parts

The ultraviolet curable resin composition A was applied onto a triacetyl cellulose (TAC) film having a thickness of 80 μm so as to have a coating thickness after drying of 7 μm, and dried in a dryer set at 60° C. for three minutes. The dried film is pressed against the uneven surface of the mold A obtained in advance so that the photocurable resin composition layer becomes the mold side by a rubber roller, and is adhered to each other. In this state, light from a high-pressure mercury lamp having a strength of 20 mW/cm ^{2 was} irradiated from the TAC film side to a light amount meter of 200 mJ/cm ² to cure the photocurable resin composition layer. Thereafter, the TAC film was peeled off from the mold together with the cured resin, and a transparent anti-glare film A composed of a laminate of a cured resin (anti-glare layer) having irregularities on the surface and a TAC film was produced.

(D) Production of anti-glare polarizing plate

For 100 parts by weight of water, 1.8 parts by weight of a carboxy-modified polyvinyl alcohol "Cola Liboville KL318" sold by Kuraray (a company having a degree of modification of 2 mol%) was dissolved, and 1.5 parts by weight of water was added thereto. A poly-polyamine epoxy resin, which is a "sumilex resin 650" (a 30% aqueous solution) sold by Sumika Chemtex Co., Ltd., was dissolved to prepare a polyvinyl alcohol-based adhesive.

After the saponification treatment was performed on the side opposite to the side on which the antiglare layer A of the antiglare film A was formed, 10 μm of the polyvinyl alcohol-based adhesive prepared as described above was applied by a screw extrusion coater, and then attached thereto. A polyvinyl alcohol-iodine polarizing film obtained in advance. Further, after coating the polyvinyl alcohol-based adhesive prepared as described above on the surface of the polyvinyl alcohol-iodine polarizing film opposite to the surface to which the anti-glare film is bonded, the surface is subjected to the surface coating. The drawn norbornene-based resin film (developed by ZEONOR, 0ptes) having a thickness of 70 μm and an in-plane retardation value R ₀ of 55 nm and a thickness direction retardation R _th of 124 nm was bonded. Thereafter, it was dried at 80 ° C for 5 minutes, and further cured at room temperature for one day to obtain an anti-glare polarizing plate A.

(E) Production of liquid crystal display device

The polarizing plate is peeled off from the liquid crystal cell of a commercially available liquid crystal television (LC-32ES50, Sharp Co., Ltd.) equipped with a liquid crystal display element (i.e., image display element) having a vertical alignment mode, on the back of the liquid crystal cell. On the (backlight side) side, a polarizing plate in which a TAC film and a polarizing film and a stretch norbornene-based resin film (ZEONOR, in-plane retardation value R ₀ is 55 nm, thickness direction retardation R _th is 124 nm) are bonded thereto In the front side (recognition side) of the liquid crystal cell, the anti-glare polarizing plate A is bonded via the adhesive layer so that the absorption axis of the polarizing plate is aligned with the absorption axis direction of the polarizing plate which is originally adhered to the liquid crystal television. , made into a liquid crystal panel. Next, the liquid crystal panel is assembled by a configuration of a backlight/light diffusing plate/liquid crystal panel to produce a liquid crystal display device A (that is, an image display device).

<Comparative column 21>

The surface of an aluminum roller (JIS A5056) having a diameter of 300 mm was mirror-polished, and a sandblasting device (developed by Fujifilm Co., Ltd.) was used. The surface of the polished aluminum was pressed at a pressure of 0.1 MPa (gauge pressure, the same below). ), the amount of beads used is 8 g/cm ² (the surface area of the roll is on average per 1 cm ² , the same applies hereinafter), and the zirconia beads TZ-SX-17 (developed by Tosoh Co., Ltd., average particle diameter: 20 μm), The surface is covered with irregularities. The obtained aluminum roll having irregularities was subjected to electroless nickel plating to prepare a mold B. At this time, the thickness of the electroless nickel plating was set to 15 μm. An anti-glare film B was produced in the same manner as in Example 21 except that the obtained mold B was used. Further, an anti-glare polarizing plate B and a liquid crystal display device B were produced in the same manner as in Example 21 except that the anti-glare film B was used.

<Comparative column 22>

The anti-glare film on the identification side polarizing plate of the commercially available liquid crystal television (LC-32ES50, developed by Sharp Co., Ltd.) is peeled off (the anti-glare is formed by dispersing fine particles in the hard coat layer) Layer), an anti-glare film C is obtained. An anti-glare polarizing plate C and a liquid crystal display device C were produced in the same manner as in Example 21 except that the anti-glare film C was used.

Fig. 17 shows a power spectrum G ² (f) obtained from the pattern used in the production of the anti-glare film A. It is understood that the power spectrum of the pattern used in the production of the anti-glare film A does not have a maximum value when the spatial frequency is more than 0 μm ^-1 and 0.04 μm ^-1 or less, and has a maximum value when it is more than 0.04 μm ^-1 and 0.08 μm ^-1 or less. .

Further, Fig. 26 shows the second-order derivative function d ² Ψ ² (f) / df ² of the power spectrum of the complex amplitude calculated from the elevation of the anti-glare films A to C. As can be seen from Fig. 26, the one-dimensional power spectrum of the complex amplitude calculated from the elevation of the anti-glare film A has two inflection points in the range of a spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less, but The one-dimensional power spectrum of the complex amplitude calculated by the elevation of the glare films B and C is not a power spectrum having two inflection points in the range of a spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less.

The anti-glare films A to C and the liquid crystal display devices A to C produced in Example 21 and Comparative Examples 21 and 22, and the results of the above evaluations are shown in Table 2.

As is clear from the results shown in Table 2, all of the image display devices A (Example 21) satisfying the requirements of the second aspect of the present invention did not cause glare at all, showing sufficient anti-glare property, and no fading occurred, showing Higher contrast. Further, when the image display device A is visually observed in a dark room or a bright room, it has a wide viewing angle characteristic. On the other hand, the image display device B (Comparative Example 21) using the anti-glare film B (see Fig. 26) which does not satisfy the requirements of the second aspect of the present invention shows a tendency to cause glare. Further, in the image display device C (Comparative Example 22) using the anti-glare film C having a high internal haze, the contrast did not occur, but the contrast was lowered.

[Symbol Description]

1 anti-glare film

2 Concavities and convexities formed on the surface of the film

3 film projection surface

5 The main normal direction of the film

6 normal of local location

6a to 6d polyhedral normal vector

7 mold substrate

8 Surface of the substrate ground by the grinding step

9 photosensitive resin film

10 exposed areas

11 unexposed area

12 mask

13 unmasked area

15 First surface uneven shape (concavo-convex shape of the surface of the substrate for the mold after the first etching step)

16 second surface uneven shape (concave-convex shape of the surface of the substrate for the mold after the second etching step)

17 chrome layer

18 chrome surface

20 elevation datum

21 highest elevation surface

40 reticle unit

41 reticle chrome shade pattern

42 the opening of the mask

43 mask

45 light box

46 light source

47 glass plate

49 flashing observation position

50 diffuser

100 anti-glare layer

101 transparent support

102, 103, 104 transparent protective film

110 liquid crystal cell

111, 112 box substrate

113, 114 electrodes

115 liquid crystal layer

120 (front side) polarizing film

121 (back side) polarizing film

130 (first) retardation film

131 (second) retardation film

[A third embodiment of the present invention]

<Liquid crystal display device>

A liquid crystal display device according to a third aspect of the present invention includes: a liquid crystal cell in which twisted nematic liquid crystal is sealed between a pair of mutually parallel cassette substrates; a front side polarizing film is disposed on an identification side of the liquid crystal cell; and a back side polarizing film is disposed. Arranging on the opposite side of the identification side of the liquid crystal cell; the optically anisotropic layer is disposed between the back side polarizing film and the liquid crystal cell and between at least one of the front side polarizing film and the liquid crystal cell; The anti-glare film includes a transparent support and an anti-glare layer, and the anti-glare layer is formed on the transparent support and has a fine uneven surface having fine irregularities on the opposite side of the transparent support, and the anti-glare film is prevented The glare layer is disposed on the opposite side of the surface facing the liquid crystal cell of the front side polarizing film so as to be the most recognizable side.

Figs. 34 to 36 show a specific example of the liquid crystal display device of the third invention. The liquid crystal display device shown in FIGS. 34 to 36 includes a liquid crystal cell 110, a pair of polarizing films 120 and 121 disposed so as to sandwich the liquid crystal cell 110, and a polarizing film and a liquid crystal cell in one or both of them. The optically anisotropic layers 330, 331 are disposed between 110.

The liquid crystal cell 110 has two block substrates 111 and 112 which are parallel to each other, and a liquid crystal layer 115 in which liquid crystal is sealed (interposed and held) between the two cassette substrates 111 and 112, on the opposing faces of the cassette substrates 111 and 112. Electrodes 113, 114 are provided, respectively. Further, the liquid crystal of the liquid crystal layer 115 of the liquid crystal cell 110 is a so-called twisted nematic liquid crystal.

In the liquid crystal display device shown in FIG. 34, the first optically anisotropic layer 330 is disposed between the cassette substrate 111 and the polarizing film 120. Further, a second optical anisotropic layer 331 is disposed between the cell substrate 112 opposite to the first optical anisotropic layer 330 and the polarizing film 121.

Further, in the liquid crystal display device shown in FIG. 34, a surface on the display surface (identification) side which is a surface opposite to the side facing the liquid crystal cell 110 of one of the polarizing films 120 is disposed to impart predetermined optical characteristics. An anti-glare film 1 having a predetermined surface shape. The anti-glare film 1 includes a transparent support 101 and an anti-glare layer 100. The anti-glare layer 100 is formed on the transparent support and has a fine uneven surface having fine irregularities on the opposite side of the transparent support. The anti-glare film 1 is disposed on the side opposite to the surface of the front-side polarizing film 120 facing the liquid crystal cell 110 such that the anti-glare layer 100 is the most recognizable side. The liquid crystal display device of the third aspect of the invention has a feature in the shape of the fine uneven surface of the anti-glare film 1. The anti-glare film 1 is the same as the first invention.

(twisted nematic liquid crystal)

The twisted nematic (hereinafter, simply referred to as "TN") type liquid crystal used in the liquid crystal display device of the third aspect of the present invention is a liquid crystal in which the alignment state of liquid crystal molecules is changed in a vertical electric field in which a voltage is applied perpendicularly to the substrate surface. In the TN mode, when the liquid crystal molecules are traced from one substrate to the other substrate, the liquid crystal alignment in a state where no voltage is applied is reversed by 90 degrees between the upper and lower substrates in the respective portions in the plane parallel to the substrate. The state of the (twisted) state is oriented parallel to the substrate surface.

In the conventional TN liquid crystal display device, the viewing angle characteristics are not sufficient due to the anisotropy of the refractive index due to the pretilt of the liquid crystal material in the liquid crystal cell. Japanese Patent Publication No. 6-214116 discloses an optically anisotropic layer that exhibits a negative uniaxiality and has an optical axis that is inclined with respect to a film surface, and is disposed on a TN liquid crystal display. Between the liquid crystal cell of the device and the polarizing plate. Japanese Laid-Open Patent Publication No. Hei 10-186356 discloses an optical compensation film in which a liquid crystal polymer exhibiting a positive uniaxiality is fixed in a liquid crystal state, and an optical compensation film is disclosed. The optical compensation film is applied to a TN type liquid crystal display device to realize a technique of expanding an angle of view. By using such an optically anisotropic layer in which the optical axis is inclined with respect to the film surface as an optical compensation film (phase difference plate), the improvement of the viewing angle of the TN liquid crystal display device is successfully achieved.

(optical anisotropic layer)

In the third aspect of the invention, the optically anisotropic layer may be disposed between at least one of the back side polarizing film and the liquid crystal cell and between the front side polarizing film and the liquid crystal cell, but is preferably disposed on the back side. Between the side polarizing film and the liquid crystal cell and between the front side polarizing film and the liquid crystal cell.

As the optically anisotropic layer, an optically anisotropic layer which optically exhibits negative uniaxiality and whose optical axis is inclined by 5 to 50° from the normal direction of the film, and optically exhibits positive uniaxiality and which is optically The optical axis is inclined from the normal direction of the film by an optically anisotropic layer of 5 to 50°.

As the optically anisotropic layer which optically exhibits negative uniaxiality and whose optical axis is inclined by 5 to 50° from the normal direction of the film, it is preferably used, for example, on a transparent resin film composed of triacetyl cellulose or the like. An organic compound described in JP-A-H06-214116, in particular, a compound having a liquid crystallinity and having a discotic molecular structure, and a compound which exhibits liquid crystallinity but exhibits negative refractive index anisotropy by an electric field or a magnetic field, And a film or the like which is oriented such that the optical axis is inclined from 5 to 50° from the film normal direction. The orientation is not only an orientation in one direction, but also a so-called hybrid orientation in which, for example, the inclination increases from one surface of the film to the other.

As an organic compound having a discotic molecular structure exhibiting liquid crystallinity, a low molecular or high molecular discotic liquid crystal is exemplified, for example, on a mother nucleus having a planar structure such as triphenylene, tribenzylbenzene or benzene. An organic compound having a linear substituent such as an alkyl group, an alkoxy group, an alkyl-substituted benzoic acid group or an alkoxy-substituted benzoic acid group is radially bonded. Among them, it is preferred that the absorbed organic compound is not displayed in the visible light region.

The organic compound having a discotic molecular structure may be used alone or in combination with other organic compounds such as a polymer matrix, in order to obtain a desired orientation. The organic compound to be used in combination is an organic compound which can disperse an organic compound having a discotic molecular structure and an organic compound having a discotic molecular structure or a discotic molecular structure to a degree that does not scatter light. Specially limited. As a film in which a layer composed of such a liquid crystalline compound is provided on a transparent base film made of a cellulose resin and the optical axis is inclined with respect to the normal line of the film, for example, a WV film (Fuji Photo Film (share) is preferably used. Ltd.))).

In addition, as an optically anisotropic layer which optically shows positive uniaxiality and the optical axis is inclined by 5 to 50 degrees from the normal direction of the film, for example, a transparent substrate composed of a cellulose resin or the like is mentioned. An organic compound film having an elongated rod-like structure as described in JP-A-10-186356, in particular, a compound film exhibiting nematic liquid crystallinity and having a molecular structure imparting positive optical anisotropy, and not displaying A film which exhibits liquid crystallinity but exhibits a positive refractive index anisotropy by an electric field or a magnetic field, and is oriented such that the optical axis is inclined from 5 to 50° in the normal direction of the film. The orientation is not only an orientation in one direction, but also a so-called hybrid orientation in which, for example, the inclination increases from one surface of the film to the other. As a film in which a layer composed of a nematic liquid crystal compound is provided on a transparent base film and the optical axis is inclined with respect to the film normal, for example, an NH film (developed by Nippon Oil Co., Ltd.) can be preferably used.

Further, by vacuum evaporation, formation of a thin film can be realized, and evaporation of a dielectric exhibiting a positive refractive index anisotropy on a transparent substrate film from a direction inclined with respect to a normal line thereof is performed during vapor deposition. It is also possible to obtain an optically anisotropic layer which is optically positively uniaxial and whose optical axis is inclined by 5 to 50° from the normal direction of the film. The dielectric used for this purpose may be any one of a dielectric material composed of an inorganic compound and a dielectric material composed of an organic compound, but it is preferably in terms of stability against heat acting during vacuum vapor deposition. Use an inorganic dielectric. As the inorganic dielectric material, it is preferable to use yttrium oxide (Ta ₂ O ₅ ), tungsten oxide (WO ₃ ), cerium oxide (SiO ₂ ), cerium oxide (SiO), or cerium oxide for the purpose of excellent transparency. A metal oxide such as (Bi ₂ O ₅ ) or ruthenium oxide (Nd ₂ O ₃ ). Among the metal oxides, it is more preferable to use a metal oxide such as ruthenium oxide, tungsten oxide or ruthenium oxide which is easy to exhibit an anisotropic refractive index and a hard film.

In the case where an optically anisotropic layer which exhibits a dielectric layer having a refractive index anisotropy is laminated on such a transparent base film, the optically anisotropic layer is in accordance with the transparent base film side and the polarizing film or The transparent protective film laminated together is laminated on the polarizing film or the transparent protective film in a facing manner.

Further, in the TN mode, in order to further improve the viewing angle characteristics and display characteristics, it is preferable to arrange an optical anisotropic layer on the back side polarizing plate which is paired with the liquid crystal cell. As the optically anisotropic layer 331 provided between the back side polarizing film 121 and the cassette substrate 112, it is preferable to use optically negative or positive uniaxiality as described above and the optical axis thereof is from the normal direction of the film. An optically anisotropic layer that is inclined between 5 and 50 degrees.

(polarized film)

The front side polarizing film 120 and the back side polarizing film 121 may be a type of polarized film or polarized light that transmits linearly polarized light that vibrates in one direction perpendicular to each other in the film surface and absorbs linearly polarized light that vibrates in the other direction. The film is known from the board. Specifically, for example, a polyvinyl alcohol-based polarizing film in which a polyvinyl alcohol film is uniaxially stretched and a high dichroic dye is dyed and a boric acid cross-linking is also used can be used. Further, an iodine-based polarizer using iodine as a high dichroic dye and a dye-based polarizer using a dichroic organic dye as a high dichroic dye can be used. Further, the polyvinyl alcohol-based polarizing film itself may be laminated on one surface or both surfaces of a polyvinyl alcohol-based polarizing film, and a triacetyl cellulose (TAC) film, an acrylic resin film, or a polyparaphenylene may be laminated. A polarizing plate of a transparent protective film such as a glycolic acid ester film or an unstretched norbornene film.

In the liquid crystal display device shown in FIG. 34, an anti-glare film 1 composed of a transparent support 101 and an anti-glare layer 100 is laminated on the front surface side of the first polarizing film 120, and laminated on the back side of the second polarizing film 121. There is a transparent protective film 102.

Further, in the liquid crystal display device shown in FIG. 35, an anti-glare film 1 and a transparent protective film 103 composed of a transparent support 101 and an anti-glare layer 100 are laminated on the front surface side and the back surface side of the first polarizing film 120, A transparent protective film 102 is laminated on the back side of the second polarizing film 121.

Further, in the liquid crystal display device shown in Fig. 36, an anti-glare film 1 composed of a transparent support 101 and an anti-glare layer 100 is laminated on the front side of the first polarizing film 120, in front of the second polarizing film 121. Transparent protective films 104 and 102 are laminated on the side and back sides.

Further, in the liquid crystal display device shown in Fig. 35, the first retardation film 330 functions as the transparent protective film 103, and the transparent protective film 103 can be omitted.

In the liquid crystal display device shown in FIGS. 34 to 36, the transparent protective film 102 is disposed on the back side of the back side polarizing film 121. As shown in FIGS. 34 and 35, when the optically anisotropic layer 331 is disposed on one surface thereof, the optically anisotropic layer 331 functions as a transparent protective film for protecting the polarizing film 121. In this case, it is also preferable to provide the transparent protective film as described above on the other surface of the polarizing film 121.

A backlight (not shown) for supplying light to the liquid crystal cell 110 is usually provided on the back side of the back side polarizing film 121 (the back side of the transparent film 103).

[Examples]

Hereinafter, the third invention will be further described in detail by way of examples, but the third invention is not limited to the embodiments. In the examples, the % and the parts indicating the content or the amount used are based on weight unless otherwise specified. Moreover, the evaluation method of the mold or the anti-glare film of the following examples is as follows.

[1] Measurement of surface shape of anti-glare film

(measurement of the elevation of the surface)

The elevation of the surface of the anti-glare film was measured using a three-dimensional microscope PLμ2300 (developed by Sensofar Co.). In order to prevent the sample from being warped, an optically transparent adhesive is used, and the surface is attached to the glass substrate so that the uneven surface becomes a surface, and is used for measurement. At the time of measurement, the magnification of the objective lens was set to 10 times for measurement. The horizontal resolutions Δx and Δy are both 1.66 μm, and the measurement area is 1270 μm × 950 μm.

(power spectrum of complex amplitude)

From the central portion of the measurement data obtained above, 512 × 512 (measured area, 850 μm × 850 μm) data were extracted, and the elevation of the fine uneven surface of the anti-glare film was set as a two-dimensional function h(x, y). Find out. From the obtained two-dimensional function h(x, y), the complex amplitude is calculated as a two-dimensional function ψ(x, y). The wavelength λ at the time of calculating the complex amplitude was set to 550 nm. The two-dimensional function ψ(x, y) is subjected to discrete Fourier transform to obtain a two-dimensional function Ψ(f _x , f _y ). The two-dimensional function Ψ(f _x ,f _y ) is squared to calculate the two-dimensional function 二维² (f _x ,f _y ) of the two-dimensional power spectrum, and then the function of the distance f from the origin is calculated, that is, the one-dimensional power spectrum The one-dimensional function Ψ ² (f). By linearly interpolating the one-dimensional function Ψ ² (f), a discrete function every 0.008 μm ^-1 is formed. From the discrete function of every 0.008 μm ^-1 , that is, the second derivative of Ψ ² (f), the inflection point of the one-dimensional power spectrum of the complex amplitude is calculated.

(inclination of the fine concave surface)

Based on the measurement data obtained above, a histogram of the inclination angle of the uneven surface is calculated based on the above-described algorithm, and the distribution of the inclination angle is obtained from the histogram, and the ratio of the surface having the inclination angle of 5 or more is calculated.

(surface roughness parameter of fine uneven surface)

The surface roughness parameter of the anti-glare film was measured using a surface roughness measuring instrument Surftest SJ-301 developed by JIS B 0601 (company) mitutoyo Co., Ltd. In order to prevent warpage of the sample, an optically transparent adhesive is used, and the surface of the uneven surface is bonded to the glass substrate to be used for measurement.

[2] Measurement of optical properties of anti-glare film

(haze)

The measurement of the full haze of the anti-glare film is as follows. The optically transparent adhesive is used to bond the anti-glare film to the glass substrate with the surface on the opposite side of the anti-glare layer forming surface, and the anti-glare film is bonded to the glass substrate. The glare film was irradiated with light from the glass substrate side, and was measured using a haze measuring instrument "HM-150" type developed by Murakami Color Technology Research Institute, JIS K 7136. In addition, the measurement of the internal haze was carried out by attaching a triacetyl cellulose film having a haze of substantially 0 to the uneven surface of the antiglare layer with glycerin, and measuring again based on JIS K 7136. The surface haze is calculated based on the above formula (12).

(through vividness)

The transmission sensibility of the anti-glare film was measured using a mapping measuring instrument "ICM-IDP" developed by Sugatest Co., Ltd. based on JIS K 7105. In this case, in order to prevent the warpage of the sample, an optically transparent adhesive is used, and the fine concavo-convex shape surface of the glare layer is bonded to the glass substrate so as to be a surface, and is used for measurement. In this state, light was incident from the glass side, and measurement was performed. The measured value here is a total value obtained by measuring four optical combs having a width of the dark portion and the bright portion of 0.125 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively. The maximum value of the transmission sharpness at this time is 400%.

(reflective sharpness)

The reflectance of the anti-glare film was measured using a mapping measuring instrument "ICM-1DP" developed by Sugatest Co., Ltd. based on JIS K 7105. In this case, in order to prevent the warpage of the sample, an optically transparent adhesive is used, and the fine embossed surface of the glare layer is bonded to the black acrylic substrate so as to prevent the surface of the glare layer from being applied to the black acrylic substrate. In this state, light was incident at 45° from the uneven surface side, and measurement was performed. The measured value here is a total value obtained by measuring four kinds of optical combs having a width of the dark portion and the bright portion of 0.5 mm, 1.0 mm, and 2.0 mm, respectively. The maximum value of the reflection sharpness at this time is 300%.

[3] Measurement of mechanical properties of anti-glare film

(pencil hardness)

The pencil hardness of the antiglare film was measured by the method specified in JIS K5600-5-4. Specifically, an electric pencil scratch hardness tester (developed by Yasuda Precision Instruments Co., Ltd.) based on this specification was used, and measurement was performed with a load of 500 g.

[4] Evaluation of liquid crystal display devices

(contrast)

In the dark room, the backlight of the liquid crystal display device was turned on, and the brightness of the liquid crystal display device in the black display state and the white display state was measured using a brightness meter BM5A type (developed by Topcon Co., Ltd.), and the contrast was calculated. Here, the contrast is expressed by the ratio of the brightness of the white display state to the brightness of the black display state.

(reflection, fading, dizziness)

The contrast evaluation system described above was moved to a bright room, and as a black display state, the reflection state and fading were visually observed. Next, in the bright room, as a white display state, visual observation was also performed regarding the flare. The evaluation criteria relating to the state of reflection, fading, and glare are as follows.

(a) reflected

1: No reflection was observed.

2: A slight reflection was observed.

3: Observing the reflection clearly.

(b) Fading

1: No fading was observed.

2: A slight fading was observed.

3: Fading was clearly observed.

(c) flashing

1, can not see the dizziness.

2. A slight dizziness was observed.

3. Strong dizziness was observed.

[5] Evaluation of patterns for the manufacture of anti-glare films

The created pattern data is set to binarized image data of two gradation, and the gradation is represented by a two-dimensional discrete function g(x, y). The horizontal resolutions Δx and Δy of the discrete function g(x, y) are both set to 2 μm. A discrete Fourier transform is performed on the obtained two-dimensional function g(x, y) to obtain a two-dimensional function G(f _x , f _y ). Square the two-dimensional function G(f _x , f _y ), calculate the two-dimensional function G ² (f _x , f _y ) of the two-dimensional power spectrum, and then calculate the function of the distance f from the origin, that is, the one-dimensional power spectrum. One-dimensional function G ² (f).

<Example 31>

(A) Production of polarizing film

A polyvinyl alcohol film having an average polymerization degree of about 2400, a degree of saponification of 99.9 mol% or more and a thickness of 75 μm was immersed in pure water at 30 ° C, and then immersed in a mass ratio of iodine/potassium iodide/water at 30 ° C. An aqueous solution of 0.02/2/100. Thereafter, it was immersed in an aqueous solution having a mass ratio of potassium iodide/boric acid/water of 12/5/100. Subsequently, it was washed with pure water at 8 ° C, and then dried at 65 ° C to obtain a polarizing film in which iodine was adsorbed and oriented on polyvinyl alcohol. The stretching was mainly carried out in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio was 5.3 times.

(B) Production of a mold for manufacturing an anti-glare film

A roller of a Ballard copper plating was prepared on the surface of an aluminum roller (JIS A5056) having a diameter of 200 mm. The Ballard copper plating is composed of a copper plating layer/thin silver plating layer/surface copper plating layer, and the thickness of the entire plating layer is set to be about 200 μm. The copper plating surface is mirror-polished, and a photosensitive resin is applied to the surface of the copper plating after polishing, and dried to form a photosensitive resin film. Next, the following pattern is exposed and developed on the photosensitive resin film by laser light, and the pattern is the pattern shown in FIG. 16 (passing through the pattern having a random luminance distribution and removing 0.035 μm ^-1 or less The low spatial frequency component and the band-pass filter of a high spatial frequency component of 0.15 μm ^-1 or more are formed by repeating the parallel arrangement. Exposure and development of laser light were carried out by Laser Stream FX (developed by Think Laboratory, Inc.). A positive photosensitive resin is used for the photosensitive resin film.

Thereafter, the first etching treatment is performed with a copper chloride solution. The etching amount at this time was set to 3 μm. The photosensitive resin film was removed from the roll after the first etching treatment, and the second etching treatment was performed again with the copper chloride liquid. The etching amount at this time was set to 10 μm. Thereafter, chrome plating was performed to prepare a mold A. At this time, the chrome plating thickness was set to 4 μm.

(C) (production of anti-glare film)

Each of the following components was dissolved in ethyl acetate at a solid concentration of 60%, and an ultraviolet curable resin composition A having a refractive index of 1.53 after curing was purchased.

60 parts of pentaerythritol triacrylate

40 parts of multifunctional urethane acrylate

(Reactive product of hexamethylene diisocyanate and pentaerythritol triacrylate) diphenyl (2,4,6-trimethoxybenzylidene) phosphine oxide 5 parts

The ultraviolet curable resin composition A was applied onto a triacetyl cellulose (TAC) film having a thickness of 80 μm so as to have a coating thickness after drying of 7 μm, and dried in a dryer set at 60° C. for three minutes. The dried film is pressed against the uneven surface of the mold A obtained in advance so that the photocurable resin composition layer becomes the mold side by a rubber roller, and is adhered to each other. In this state, light from a high-pressure mercury lamp having a strength of 20 mW/cm ^{2 was} irradiated from the TAC film side to an amount of 200 mJ/cm ² in terms of an h-line conversion, and the photocurable resin composition layer was cured. Thereafter, the TAC film was peeled off from the mold together with the cured resin, and a transparent anti-glare film A composed of a laminate of a cured resin (anti-glare layer) having irregularities on the surface and a TAC film was produced.

(D) Production of anti-glare polarizing plate

For 100 parts by weight of water, 1.8 parts by weight of a carboxyl modified polyvinyl alcohol "Cola Liboville KL318" sold by Kuraray (Company degree: 2 mol%) was dissolved, and 1.5 parts by weight of water was added thereto. A poly-polyamine epoxy resin, which is a "Sumilex resin 650" (a 30% aqueous solution) sold by Sumika Chemtex Co., Ltd., was dissolved to prepare a polyvinyl alcohol-based adhesive.

After the saponification treatment was performed on the side opposite to the side on which the antiglare layer A of the antiglare film A was formed, 10 μm of the polyvinyl alcohol-based adhesive prepared as described above was applied by a screw extrusion coater, and then attached thereto. A polyvinyl alcohol-iodine polarizing film obtained in advance. Further, after coating a 10 μm-long polyvinyl alcohol-based adhesive prepared as described above on a surface of the polyvinyl alcohol-iodine polarizing film opposite to the surface to which the anti-glare film is bonded, with a screw extrusion coater, The film of the optically oriented layer (trade name "WV film", developed by Fuji Photo Film Co., Ltd.) is bonded after saponification, and the optically anisotropic layer is coated and fixed on the substrate. a negatively uniaxial discotic liquid crystal molecule whose optical axis is sequentially inclined from 5 to 50° from the normal direction of the film, and the apparent optical axis as a whole is located from the normal line. 18° direction. Thereafter, it was dried at 80 ° C for 5 minutes, and further cured at room temperature for one day to obtain an anti-glare polarizing plate A.

(E) Production of liquid crystal display device

The polarizing plate is peeled off from the liquid crystal cell of a commercially available monitor (W2261VG-PF, LG Electronics) equipped with a TN mode liquid crystal display element (ie, an image display element), and is on the back side (backlight side) side of the liquid crystal cell. An optical anisotropic layer [trade name "WV film", developed by Fuji Photo Film Co., Ltd.) and a triethylene fluorene fiber adhered to the other side of the polarizer will be adhered to one side of the polyvinyl alcohol-iodine linear polarizer. A linear film polarizer/optical directional layer laminate [product name "Sumikalan SRH862A", developed by Sumitomo Chemical Co., Ltd.], and the above-mentioned anti-glare polarizing plate A is formed on the front side (recognition side) of the liquid crystal cell The absorption axis of the polarizing plate is bonded to the absorption axis direction of the polarizing plate of the liquid crystal television, and is bonded to the liquid crystal panel through the adhesive layer; and the optical anisotropic layer [trade name" In the WV film ", developed by Fuji Photo Film Co., Ltd.], optically negative uniaxial discotic liquid crystal molecules are coated and fixed on a substrate, and the optical axis thereof is 5 to 50 from the normal direction of the film. Tilting in order The mixed orientation, as the overall apparent optical axis, lies in a direction from the normal of about 18°. Next, the liquid crystal panel is assembled by a configuration of a backlight/light diffusing plate/liquid crystal panel to form a liquid crystal display device A (that is, an image display device).

<Comparative Example 31>

The surface of an aluminum roller (JIS A5056) having a diameter of 300 mm was mirror-polished, and a sandblasting device (developed by Fujifilm Co., Ltd.) was used. The surface of the polished aluminum was pressed at a pressure of 0.1 MPa (gauge pressure, the same below). ), the amount of beads used is 8 g/cm ² (the surface area of the roll is on average per 1 cm ² , the same applies hereinafter), and the zirconia beads TZ-SX-17 (developed by Tosoh Co., Ltd., average particle diameter: 20 μm), The surface is covered with irregularities. The obtained aluminum roll having irregularities was subjected to electroless nickel plating to prepare a mold B. At this time, the thickness of the electroless nickel plating was set to 15 μm. An anti-glare film B was produced in the same manner as in Example 31 except that the obtained mold B was used. Further, an anti-glare polarizing plate B and a liquid crystal display device B were produced in the same manner as in Example 31 except that the anti-glare film B was used.

Fig. 17 shows a power spectrum G ² (f) obtained from the pattern used in the production of the anti-glare film A. It is understood that the power spectrum of the pattern used in the production of the anti-glare film A does not have a maximum value when the spatial frequency is more than 0 μm ^-1 and 0.04 μm ^-1 or less, and has a maximum value when it is more than 0.04 μm ^-1 and 0.08 μm ^-1 or less. .

Further, Fig. 33 shows the second-order derivative function d ² Ψ ² (f)/df ² of the power spectrum of the complex amplitude calculated from the elevations of the anti-glare films A and B. As can be seen from Fig. 33, the one-dimensional power spectrum of the complex amplitude calculated from the elevation of the anti-glare film A has two inflection points in the range of the spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less, but from the anti-glare The one-dimensional power spectrum of the complex amplitude calculated by the elevation of the films B and C is not a power spectrum having two inflection points in the range of a spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less.

The anti-glare films A and B and the liquid crystal display devices A and B produced in Example 31 and Comparative Example 31 are shown in Table 3 as a result of performing the above evaluations.

As is clear from the results shown in Table 3, all of the image display devices A (Example 31) satisfying the requirements of the third aspect of the present invention did not cause glare at all, showing sufficient anti-glare properties, and no fading occurred, showing Higher contrast and wide field of view characteristics. On the other hand, the image display device B (Comparative Example 31) using the anti-glare film B (see Fig. 33) which does not satisfy the requirements of the third invention shows a tendency to cause glare.

[Symbol Description]

1 anti-glare film

2 Concavities and convexities formed on the surface of the film

3 film projection surface

5 The main normal direction of the film

6 normal of local location

6a to 6d polyhedral normal vector

7 mold substrate

8 Surface of the substrate ground by the grinding step

9 photosensitive resin film

10 exposed areas

11 unexposed area

12 mask

13 unmasked area

15 First surface uneven shape (concavo-convex shape of the surface of the substrate for the mold after the first etching step)

16 second surface uneven shape (concave-convex shape of the surface of the substrate for the mold after the second etching step)

17 chrome layer

18 chrome surface

20 elevation datum

21 highest elevation surface

40 reticle unit

41 reticle chrome shade pattern

42 the opening of the mask

43 mask

45 light box

46 light source

47 glass plate

49 flashing observation position

50 diffuser

100 anti-glare layer

101 transparent support

102, 103, 104 transparent protective film

110 liquid crystal cell

111, 112 box substrate

113, 114 electrodes

115 liquid crystal layer

120 (front side) polarizing film

121 (back side) polarizing film

330 (first) optical anisotropic layer

331 (second) optical anisotropic layer

[A fourth embodiment of the present invention]

<Liquid crystal display device>

A liquid crystal display device according to a fourth aspect of the present invention includes: a liquid crystal cell in which liquid crystal is sealed between a pair of mutually parallel cassette substrates, and the liquid crystal is oriented in substantially the same direction parallel to the cassette substrate; and a front side polarizing film is disposed in the liquid crystal display device. a recognition side of the liquid crystal cell; a rear side polarizing film disposed on the opposite side; the anti-glare film including a transparent support and an anti-glare layer, wherein the anti-glare layer is formed on the transparent support and is provided on the transparent support The fine uneven surface having the fine unevenness on the side is disposed on the opposite side of the surface of the front-side polarizing film facing the liquid crystal cell so that the anti-glare layer is the most recognizable side.

Figures 37 and 38 show a specific example of the liquid crystal display device of the fourth invention. In the liquid crystal display device of the fourth aspect of the invention, the front side polarizing film 120 is disposed on the side of the liquid crystal cell 110, and the back side polarizing film 121 is disposed on the opposite side.

The liquid crystal cell 110 is sealed with liquid crystal between a pair of mutually parallel cassette substrates 111 and 112 to form a liquid crystal layer 413. In the liquid crystal layer 413, in the no-voltage application state, the liquid crystal molecules 414 are oriented substantially parallel to the cell substrates / 111, 112 and in substantially the same direction. Further, the orientation of the long axis of the liquid crystal molecules 414 is changed in parallel with the plane of the cell substrate by the change in the voltage applied to the liquid crystal cell, and display is performed. That is, the liquid crystal display device of the fourth aspect of the invention is a so-called liquid crystal display device of a planar switch (IPS) mode. In the liquid crystal display device of the IPS mode, since the liquid crystal molecules are aligned in the same direction parallel to the substrate surface, the viewing angle characteristics are superior to those of the other modes.

Regarding the front side polarizing film 120, FIG. 37 shows that the anti-glare film 1 composed of the transparent supporting body 101 and the anti-glare layer 100 is provided on the identification side surface of the polarizing film 120, and is also provided with transparent protection on the side surface of the liquid crystal cell. An example of the film 103. Further, Fig. 38 shows that the anti-glare film 1 composed of the transparent support 101 and the anti-glare layer 100 is provided on the surface of the identification side of the polarizing film 120, and a transparent protective film is not provided on the side surface of the liquid crystal cell, but a polarizing film is provided. 120 is an example in which it is directly bonded to the cassette substrate 111 of the liquid crystal cell 110. In Figs. 37 and 38, only the presence or absence of the transparent protective film 103 is different.

Here, as shown in FIG. 37, in the case where the transparent protective film 103 is present between the polarizing film 120 and the cassette substrate 111, the thickness direction phase difference _{Rth of} the transparent protective film is preferably from -10 nm to +40 nm. In the range, it is more preferably in the range of -0.1 nm to +40 nm. Further, in the case where there are other layers between the polarizing film 120 and the cassette substrate 111, it is preferable that the thickness direction phase difference _Rth between the surface of the liquid crystal cell 110 of the polarizing film 120 and the front side surface of the liquid crystal cell is In the range of -10 nm to +40 nm. As shown in Fig. 38, in the case where the polarizing film 120 is directly bonded to the cassette substrate 111, the phase difference from the liquid crystal cell side surface of the polarizing film 120 to the front side surface of the liquid crystal cell (the cassette substrate 111) is zero.

Here, the planar phase difference R ₀ and the thickness direction phase difference R _{th of the} birefringent layer and the retardation film are n _x in the retardation axis direction in the plane of each film, and are in-plane and retarded. When the refractive index in the direction perpendicular to the axis is n _y , the refractive index in the thickness direction is n _z , and the film thickness is d, they are defined by the following formulas (A) and (B).

R ₀ =(n _x -n _y )×d (A)

R _th =[(n _x +n _y )/2-n _z ]×d (B)

In other words, the plane phase difference R ₀ is a value obtained by multiplying the in-plane refractive index difference by the film thickness, and the thickness direction phase difference R _th is a value obtained by multiplying the difference between the in-plane average refractive index and the thickness direction refractive index by the film thickness.

The anti-glare film 1 is disposed on the surface on the display surface (recognition) side of the front side polarizing film 120. The anti-glare film 1 includes a transparent support 101 and an anti-glare layer 100. The anti-glare layer 100 is formed on the transparent support and has a fine uneven surface having fine irregularities on the opposite side of the transparent support. The anti-glare film 1 is a film which imparts predetermined optical characteristics and has a predetermined surface shape. The anti-glare film 1 is disposed on the side opposite to the surface of the front-side polarizing film 120 facing the liquid crystal cell 110 such that the anti-glare layer 100 is the most recognizable side. The liquid crystal display device of the fourth aspect of the invention has a feature in the shape of the fine uneven surface of the anti-glare film 1. The anti-glare film 1 is the same as the first invention.

The retardation film 130 may be disposed between the back side polarizing film 121 and the liquid crystal cell 110. In this case, the thickness direction phase difference of the birefringent layer including the retardation film 130 existing between the liquid crystal cell side surface of the back side polarizing film 121 and the surface of the cell substrate 112 on the back side of the liquid crystal cell 110 is present. The sum of R _th is preferably in the range of -40 nm to +40 nm, and the sum of the in-plane phase differences R ₀ of both is preferably in the range of 100 nm to 300 nm.

The front side polarizing plate composed of the front side polarizing film 120, the anti-glare film 1 and the transparent protective film 103, and the liquid crystal cell 110 (between the transparent protective film 103 and the liquid crystal cell 110) and the Fig. 38 are shown in Fig. 37. The front side polarizing film 120 and the front side polarizing film 1 and the liquid crystal cell 110 (between the polarizing film 120 and the liquid crystal cell 110) are usually adhered with an adhesive, respectively. Further, in Figs. 37 and 38, between the back side polarizing plate and the retardation film 130 (between the transparent protective film 104 and the retardation film 130) composed of the back side polarizing film 121 and the transparent protective films 102 and 104 or The phase difference film 130 and the liquid crystal cell 110 are also usually adhered with a binder, respectively. As such a binder, a binder excellent in transparency such as acrylic is usually used. 0286

A backlight (not shown) for supplying light to the liquid crystal cell 110 is usually provided on the back side polarizing film 121 on the back surface of the transparent protective film 102.

(polarized film)

The front side polarizing film 120 and the back side polarizing film 121 may be a type of polarized film or a polarizing plate that transmits linearly polarized light that vibrates in one direction perpendicular to each other in the film surface and absorbs linearly polarized light that vibrates in the other direction. And the film is known. Specifically, for example, a polyvinyl alcohol-based polarizing film in which a polyvinyl alcohol film is uniaxially stretched and a high dichroic dye is dyed and a boric acid cross-linking is also used can be used. Further, an iodine-based polarizer using iodine as a high dichroic dye and a dye-based polarizer using a dichroic organic dye as a high dichroic dye can be used. In the polyvinyl alcohol-based polarizing film subjected to such stretching and dyeing, the stretching direction is the absorption axis, and the direction perpendicular to the absorption axis in the plane becomes the transmission axis.

In the liquid crystal display device of the fourth aspect of the invention, the transmission axis of the back side polarizing film 121 is substantially parallel to the longitudinal axis of the liquid crystal molecule, which is the slow phase axis of the liquid crystal layer 413 in the liquid crystal cell 110. Configured in a roughly vertical manner. Further, the transmission axis of the back side polarizing film 121 and the transmission axis of the front side polarizing film 120 are arranged substantially perpendicularly. In the present specification, the term "substantially" when it is said to be substantially parallel or substantially perpendicular means that it is preferably completely parallel or perpendicular, but practically, it is allowed to be about ±5° around the angle. When the transmission axis of the back side polarizing film 121 and the slow axis of the liquid crystal layer 413 of the voltageless application state are parallel, the liquid crystal display device is normally black. On the other hand, when the transmission axis of the back side polarizing film 121 and the slow axis of the liquid crystal layer 413 of the voltageless application state are perpendicular to each other, the liquid crystal display device is normally white. The transmission axis of the back side polarizing film 121 and the slow axis of the liquid crystal layer 413 of the voltageless application state are preferably arranged substantially in parallel.

In the fourth aspect of the invention, the surface of the front side polarizing film 120 opposite to the surface facing the liquid crystal cell 110, that is, the surface on the display surface (identification) side, is disposed on the surface having the predetermined optical characteristics and having a predetermined surface shape. Glare film 1.

(low phase difference transparent protective film)

As shown in Fig. 37, in the case where the transparent protective film 103 is also disposed on the liquid crystal cell side of the front side polarizing film 120, between the liquid crystal cell side surface of the front side polarizing film 120 and the front side surface of the liquid crystal cell 110 The birefringent layer present is only the transparent protective film 103 disposed on the liquid crystal cell side of the front side polarizing film 12. In this case, the thickness direction phase difference R _{th of} the transparent protective film 103 may be in the range of -10 nm to +40 nm, but it is particularly preferably in the range of -10 nm to +10 nm, and more preferably further. -5 nm to +5 nm range.

For example, in the case of a cyclic olefin-based resin film, a film having no orientation and having a thickness direction retardation _Rth of 10 nm or less and further 5 nm or less can be commercially obtained. In addition, as for the cellulose acetate-based resin film such as triacetin cellulose, a film having no orientation and having a thickness direction retardation _Rth of 10 nm or less and further 5 nm or less can be commercially obtained. In addition, even in the solvent-cast film of a cellulose acetate-based resin film such as triacetonitrile cellulose, the thickness direction retardation _Rth of the thin film is 40 nm or less. A commercially available product of a transparent protective film having a low phase difference is a non-oriented cyclic olefin resin film or a non-oriented cellulose acetate resin film (Z-TAC developed by Fujifilm Co., Ltd.). (R ₀ = 2 nm, R _th = 0 nm), KC4UE (thickness 40 μm, R ₀ = 0.7 nm, R _th = -0.1 nm, etc.) developed by Konica Minolta Opto Co., Ltd., thin-walled cellulose acetate Resin film.

In addition, the transparent protective film may not be provided on the liquid crystal cell side of the front side polarizing film 120, and the polarizing film 120 may be directly bonded to the front surface side of the liquid crystal cell 110 (the cassette substrate 111) via an adhesive or the like. In this case, the thickness direction phase difference R _th from the liquid crystal cell side surface of the front side polarizing film 120 to the front side surface of the liquid crystal cell 110 is substantially zero.

Here, in terms of the phase difference value of the film, it can be developed, for example, by attaching a film to be measured to a glass plate via a binder, using a commercially available phase difference measuring device, for example, Prince Measurement Equipment Co., Ltd. "KOBRA-21ADH" and the like are directly measured. In the phase difference measuring device as described above, for example, the in-plane phase difference R _{0 of} the film is measured by a rotational-detection method with monochromatic light having a wavelength of 559 nm; on the other hand, the in-plane of the film is measured. The retardation axis is the tilting axis and the phase difference R ₄₀ when tilted by 40 degrees, using the thickness d of the film and the average refractive index n _{0 of the} film, from the following formulas (A), (D) and (E), by numerical values In the calculation, n _x , n _{y ,} and n _{z are obtained} , and these are substituted into the above formula (B), and the thickness direction phase difference R _{th is} calculated. Further, the formula (A) is the same as described above.

R ₀ =(n _x -n _y )×d (A)

R ₄₀ =(n _x -n _y ')×d/cos(φ) Formula (D)

(n _x +n _y +n _z )/3=n ₀ (E)

among them,

φ=sin ^-1 [sin(40°)/n ₀ ]

n _y '=n _y ×n _z /[n _y ² ×sin ² (φ)+n _z ² ×cos ² (φ)] ^1/2

(transparent protective film, transparent support)

The transparent protective films 104 and 102 provided on both surfaces of the back side polarizing film 121 and the transparent support 101 of the antiglare film 1 are usually composed of a transparent resin film, for example, cellulose acetate containing triacetyl cellulose. An ester-based resin, a cyclic olefin-based resin having a polycyclic cyclic olefin such as norbornene or dimethylene quinolate, or a polycarbonate-based resin. Among them, a cellulose acetate-based resin (particularly, triacetyl cellulose) and a cyclic olefin-based resin are preferably used. Among the commercial products of the cyclic olefin resin, "ARTON" sold by JSR shares, "ZEONOR" and "ZEONEX" (both trade names) sold by Japan Zeon Co., Ltd., and the like are available.

(phase difference film)

As shown in FIGS. 37 and 38, at least one retardation film 130 may be disposed between the back side polarizing film 121 and the liquid crystal cell 110 on the back side of the liquid crystal cell 110. Further, in the liquid crystal display device of the fourth invention, a retardation film is not essential.

The retardation film 130 disposed between the back side polarizing film 121 and the liquid crystal cell 110 may be disposed such that the slow axis and the absorption axis of the back side polarizing film 121 are substantially parallel or substantially perpendicular, but particularly preferably Vertical configuration. Further, the retardation film 130 is preferably disposed so as to be substantially parallel to the longitudinal axis of the liquid crystal molecule, which is the slow phase axis of the liquid crystal layer 413 located in the liquid crystal cell 110.

When the retardation film 130 is disposed between the back side polarizing film 121 and the liquid crystal cell 110, it exists between the liquid crystal cell side surface of the back side polarizing film 121 and the back side surface of the liquid crystal cell 110 (the cassette substrate 112). The sum of the thickness direction phase differences R _th of the birefringent layer including the retardation film 130 is preferably in the range of -40 nm to +40 nm, and the sum of the in-plane phase differences R ₀ of the both is preferably 100 nm to The range of 300 nm. When the sum of R _th exceeds ±40 nm, the hue deviation caused by the angle of view increases, which is not preferable, and when the sum of R ₀ is out of the range, the brightness and the hue deviation caused by the angle of view are deteriorated, Not good.

As shown in FIGS. 37 and 38, when the transparent protective film 104 is provided on the liquid crystal cell 110 side surface (between the back side polarizing film 121 and the retardation film 130) of the back side polarizing film 121, as the transparent protective film, It is preferable to use a so-called C-type cathode plate in which the in-plane principal refractive indices n _x and n _{y are} substantially the same, and there is almost no in-plane phase difference, and the refractive index n _{z in the} thickness direction is larger than the in-plane main body. The refractive indices n _x and n _{y are} slightly smaller, have a negative uniaxiality, and their optical axes appear in a substantially normal direction. In the C-type cathode plate, the thickness direction phase difference R _th takes a positive value. When a C-type cathode plate is used, the retardation film 130 disposed between the back side polarizing film 121 and the liquid crystal cell 110 has a shape of n _x ≧n _z >n _y or n _z >n _x >n. The refractive index structure of _y and the thickness direction phase difference R _th may be formed into a film having a substantially zero or negative value so as to satisfy the above conditions in a combination of a phase difference with the thickness direction of the transparent protective film 104. Specifically, the thermoplastic resin film disclosed in Japanese Laid-Open Patent Publication No. Hei 7-230007 is uniaxially stretched and oriented in the thickness direction, and has a negative refractive index difference in polystyrene or the like. A so-called A-type cathode plate (which may also be biaxial) obtained by stretching a directional thermoplastic resin film along a uniaxial or biaxial direction, a so-called C type having a positive uniaxiality and an optical axis in the normal direction of the film. A film of a so-called A-type cathode plate having a negative uniaxiality and an optical axis in a direction parallel to the film surface is laminated on the anode plate.

As described above, in the case where the retardation film 130 is disposed, two or more retardation films may be used in combination to bring the liquid crystal cell side surface of the back side polarizing film 121 to the liquid crystal cell 110 (the cassette substrate). The phase difference between the back side surfaces of 112) reaches the desired phase difference.

In addition, the transparent protective film 104 on the liquid crystal cell side of the back side polarizing film 121 may be omitted, and the retardation film 130 may function as a protective layer of the back side polarizing film 121. In this case, the retardation film 130 itself in the thickness direction retardation R _th + -40nm to retardation R ₀ and can be in the range of 100nm to 300nm in the plane in the range of 40nm. In this case, it is also possible to use a film in which the thermoplastic resin film as described above is uniaxially stretched and also oriented in the thickness direction, and a type A cathode plate or a C type anode plate which may also be biaxial. A film or the like in which an A-type cathode plate is laminated.

When the material of the retardation film 130 is described, a polycarbonate resin is preferably used as the film in which the thermoplastic resin film is uniaxially stretched and oriented in the thickness direction. As the A-type cathode plate, a styrene-based resin, an N-phenylmaleic acid imide/α-olefin copolymer resin, or the like is preferably used. Further, the C-type anode plate is obtained by forming a rod-like liquid crystal compound layer on the vertical alignment film.

Further, the retardation film 130 disposed between the back side polarizing film 121 and the liquid crystal cell 110 is preferably used as n _x , n _{y ,} and n _z as in the case of deriving the above formulas (A) and (B). The three-direction refractive index as defined and the Nz coefficient defined by the following formula (C) is in the range of -0.5 to +0.5.

Nz=(n _x -n _z )/(n _x -n _y ) Formula (C)

The Nz coefficient is a ratio of the difference between the in-plane maximum refractive index (refractive index in the slow axis direction) and the refractive index in the thickness direction to the in-plane refractive index difference, and is an index indicating the degree of orientation in the thickness direction. For example, in a so-called A-type anode plate (n _x >n _y ≒n _z ) showing positive uniaxiality and an optical axis in the plane, Nz≒1; showing negative uniaxiality and the optical axis is in-plane In the so-called A-type cathode plate (n _x ≒n _z >n _y ), Nz ≒ 0. In the case where a laminate composed of a plurality of pieces is used as the retardation film 130, the Nz coefficient of the entire laminate is preferably within the above range.

In the case where a laminate composed of a plurality of blocks is used as the retardation film 130, and at least two of them have an in-plane phase difference, each of the retardation films having an in-plane retardation is used. The retardation axes are stacked in the same direction, and an example in which the in-plane phase difference of the entire laminate is the sum of the in-plane phase difference values is a general example. Similarly, in the case where the back side polarizing film 121 has the transparent protective film 104 on the liquid crystal cell side, when the transparent protective film 104 has an in-plane phase difference, the slow axis and the retardation axis of the retardation film 130 are in the same direction. An example of cascading is a general example. However, if the in-plane retardation of the transparent protective film 104 is, for example, about 5 nm or less, the value is virtually negligible, so that the direction of the slow axis may not be particularly noted. Further, the thickness direction phase difference of the entire laminate is the sum of the thickness direction phase differences shown by the respective retardation films laminated.

Further, on the front side of the liquid crystal cell 110, a retardation film may be provided between the front side polarizing film 120 and the liquid crystal cell 110 as needed, in that case, from the liquid crystal cell side surface of the front side polarizing film 120 to the liquid crystal. The thickness direction phase difference _Rth between the front side surfaces of the cartridge 110 (the cassette substrate 111) is also preferably in the range of -10 nm to +40 nm. When the thickness direction phase difference _Rth between the liquid crystal cell side surface of the front side polarizing film 120 and the front side surface of the liquid crystal cell 110 is out of the range, the color tone is realized by the retardation film 130 disposed on the back side. The compensation is not appropriate, so the tendency of blue enhancement is enhanced in the hue when viewing the picture from the oblique direction.

[Examples]

Hereinafter, the fourth invention will be further described in detail by way of examples, but the fourth invention is not limited to the embodiments. In the examples, the % and the parts indicating the content or the amount used are the weight basis unless otherwise specified. Moreover, the evaluation method of the mold or the anti-glare film of the following examples is as follows.

[1] Measurement of surface shape of anti-glare film

(measurement of the elevation of the surface)

The elevation of the surface of the anti-glare film was measured using a three-dimensional microscope PLμ2300 (developed by Sensofar Co.). In order to prevent the sample from being warped, an optically transparent adhesive is used, and the surface is attached to the glass substrate so that the uneven surface becomes a surface, and is used for measurement. At the time of measurement, the magnification of the objective lens was set to 10 times for measurement. The horizontal resolutions Δx and Δy are both 1.66 μm, and the measurement area is 1270 μm × 950 μm.

(power spectrum of complex amplitude)

From the central portion of the measurement data obtained above, 512 × 512 (measured area, 850 μm × 850 μm) data were extracted, and the elevation of the fine uneven surface of the anti-glare film was set as a two-dimensional function h(x, y). Find out. From the obtained two-dimensional function h(x, y), the complex amplitude is calculated as a two-dimensional function ψ(x, y). The wavelength λ at the time of calculating the complex amplitude was set to 550 nm. The two-dimensional function ψ(x, y) is subjected to discrete Fourier transform to obtain a two-dimensional function Ψ(f _x , f _y ). The two-dimensional function Ψ(f _x ,f _y ) is squared to calculate the two-dimensional function 二维² (f _x ,f _y ) of the two-dimensional power spectrum, and then the function of the distance f from the origin is calculated, that is, the one-dimensional power spectrum The one-dimensional function Ψ ² (f). By linearly interpolating the one-dimensional function Ψ ² (f), a discrete function every 0.008 μm ^-1 is formed. From the discrete function of every 0.008 μm ^-1 , that is, the second derivative of Ψ ² (f), the inflection point of the one-dimensional power spectrum of the complex amplitude is calculated.

(inclination of the fine concave surface)

Based on the measurement data obtained above, a histogram of the inclination angle of the uneven surface is calculated based on the above-described algorithm, and the distribution of each inclination angle is obtained from the histogram, and the ratio of the surface having the inclination angle of 5 or more is calculated.

(surface roughness parameter of fine uneven surface)

The surface roughness parameter of the anti-glare film was measured using a surface roughness measuring instrument Surftest SJ-301 developed by JIS B 0601 (company) mitutoyo. In order to prevent warpage of the sample, an optically transparent adhesive is used, and the surface of the uneven surface is bonded to the glass substrate to be used for measurement.

[2] Measurement of optical properties of anti-glare film

(haze)

The measurement of the full haze of the anti-glare film is as follows. The anti-glare film is bonded to the glass substrate by using an optically transparent adhesive on the surface opposite to the anti-glare layer forming surface, and the obtained glass substrate is bonded to the glass substrate. The anti-glare film was used to measure light from the glass substrate side, and was measured using a haze meter "HM-150" type developed by Murakami Color Technology Research Institute, JIS K 7136. In addition, the measurement of the internal haze was carried out by attaching a triacetyl cellulose film having a haze of substantially 0 to the uneven surface of the antiglare layer with glycerin, and measuring again based on JIS K 7136. The surface haze is calculated based on the above formula (12).

(through vividness)

The transmission sensibility of the anti-glare film was measured using a mapping measuring instrument "ICM-IDP" developed by Sugatest (Company Co., Ltd.) based on JIS K 7105. In this case, in order to prevent the warpage of the sample, an optically transparent adhesive is used, and the fine concavo-convex shape surface of the glare layer is bonded to the glass substrate so as to be a surface, and is used for measurement. In this state, light was incident from the glass side, and measurement was performed. The measured value here is a total value obtained by measuring four optical combs having a width of the dark portion and the bright portion of 0.125 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively. The maximum value of the transmission sharpness at this time is 400%.

(reflective sharpness)

The reflection sharpness of the anti-glare film was measured using a mapping measuring instrument "ICM-1DP" developed by Sugatest (Company Co., Ltd.) based on JIS K 7105. In this case, in order to prevent the warpage of the sample, an optically transparent adhesive is used, and the fine embossed surface of the glare layer is bonded to the black acrylic substrate so as to prevent the surface of the glare layer from being applied to the black acrylic substrate. In this state, light was incident at 45° from the uneven surface side, and measurement was performed. The measured value here is a total value obtained by measuring four kinds of optical combs having a width of the dark portion and the bright portion of 0.5 mm, 1.0 mm, and 2.0 mm, respectively. The maximum value of the reflection sharpness at this time is 300%.

[3] Measurement of mechanical properties of anti-glare film

(pencil hardness)

The pencil hardness of the antiglare film was measured by the method specified in JIS K5600-5-4. Specifically, an electric pencil scratch hardness tester (developed by Yasuda Precision Instruments Co., Ltd.) based on this specification was used, and measurement was performed with a load of 500 g.

[4] Evaluation of liquid crystal display devices

(contrast)

In the dark room, the backlight of the liquid crystal display device was turned on, and the brightness of the liquid crystal display device in the black display state and the white display state was measured using a brightness meter BM5A type (developed by Topcon Co., Ltd.), and the contrast was calculated. Here, the contrast is expressed by the ratio of the brightness of the white display state to the brightness of the black display state.

(reflection, fading, dizziness)

The contrast evaluation system described above was moved to a bright room, and as a black display state, the reflection state and fading were visually observed. Next, in the bright room, as a white display state, visual observation was also performed regarding the flare. The evaluation criteria relating to the state of reflection, fading, and glare are as follows.

(a) reflected

1: No reflection was observed.

2: A slight reflection was observed.

3: Observing the reflection clearly.

(b) Fading

1: No fading was observed.

2: A slight fading was observed.

3: Fading was clearly observed.

(c) flashing

1, can not see the dizziness.

2. A slight dizziness was observed.

3. Strong dizziness was observed.

[5] Evaluation of patterns for the manufacture of anti-glare films

The created pattern data is set to binarized image data of two gradation, and the gradation is represented by a two-dimensional discrete function g(x, y). The horizontal resolutions Δx and Δy of the discrete function g(x, y) are both set to 2 μm. A discrete Fourier transform is performed on the obtained two-dimensional function g(x, y) to obtain a two-dimensional function G(f _x , f _y ). Square the two-dimensional function G(f _x , f _y ), calculate the two-dimensional function G ² (f _x , f _y ) of the two-dimensional power spectrum, and then calculate the function of the distance f from the origin, that is, the one-dimensional power spectrum. One-dimensional function G ² (f).

<Example 41>

(A) Production of polarizing film

A polyvinyl alcohol film having an average polymerization degree of about 2400, a degree of saponification of 99.9 mol% or more and a thickness of 75 μm was immersed in pure water at 30 ° C, and then immersed in a mass ratio of iodine/potassium iodide/water at 30 ° C. An aqueous solution of 0.02/2/100. Thereafter, it was immersed in an aqueous solution having a mass ratio of potassium iodide/boric acid/water of 12/5/100. Subsequently, it was washed with pure water at 8 ° C, and then dried at 65 ° C to obtain a polarizing film in which iodine was adsorbed and oriented on polyvinyl alcohol. The stretching was mainly carried out in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio was 5.3 times.

(B) Production of a mold for manufacturing an anti-glare film

A roller of a Ballard copper plating was prepared on the surface of an aluminum roller (JIS A5056) having a diameter of 200 mm. The Ballard copper plating is composed of a copper plating layer/thin silver plating layer/surface copper plating layer, and the thickness of the entire plating layer is set to be about 200 μm. The copper plating surface is mirror-polished, and a photosensitive resin is applied to the surface of the copper plating after polishing, and dried to form a photosensitive resin film. Next, the following pattern is exposed and developed on the photosensitive resin film by laser light, and the pattern is the pattern shown in FIG. 16 (passing through the pattern having a random luminance distribution and removing 0.035 μm ^-1 or less The low spatial frequency component and the band-pass filter of a high spatial frequency component of 0.15 μm ^-1 or more are formed by repeating the parallel arrangement. Exposure and development of laser light were carried out by Laser Stream FX (developed by Think Laboratory, Inc.). A positive photosensitive resin is used for the photosensitive resin film.

Thereafter, the first etching treatment is performed with a copper chloride solution. The etching amount at this time was set to 3 μm. The photosensitive resin film was removed from the roll after the first etching treatment, and the second etching treatment was performed again with the copper chloride liquid. The etching amount at this time was set to 10 μm. Thereafter, chrome plating was performed to prepare a mold A. At this time, the chrome plating thickness was set to 4 μm.

(C) (production of anti-glare film)

Each of the following components was dissolved in ethyl acetate at a solid concentration of 60%, and an ultraviolet curable resin composition A having a refractive index of 1.53 after curing was purchased.

60 parts of pentaerythritol triacrylate

40 parts of multifunctional urethane acrylate

(Reactive product of hexamethylene diisocyanate and pentaerythritol triacrylate) diphenyl (2,4,6-trimethoxybenzyl fluorenyl) phosphine oxide 5 parts

The ultraviolet curable resin composition A was applied onto a triacetyl cellulose (TAC) film having a thickness of 80 μm so as to have a coating thickness after drying of 7 μm, and dried in a dryer set at 60° C. for three minutes. The dried film is pressed against the uneven surface of the mold A obtained in advance so that the photocurable resin composition layer becomes the mold side by a rubber roller, and is adhered to each other. In this state, light from a high-pressure mercury lamp having a strength of 20 mW/cm ^{2 was} irradiated from the TAC film side to an amount of 200 mJ/cm ² in terms of an h-line conversion, and the photocurable resin composition layer was cured. Thereafter, the TAC film was peeled off from the mold together with the cured resin, and a transparent anti-glare film A composed of a laminate of a cured resin (anti-glare layer) having irregularities on the surface and a TAC film was produced.

(D) Production of anti-glare polarizing plate

1.8 parts by weight of a carboxy-modified polyvinyl alcohol "Cola Liboville KL318" sold by Kuraray (Company degree: 2 mol%) was dissolved with respect to 100 parts by weight of water, and 1.5 parts by weight was further added. A water-soluble polyamine epoxy resin, that is, "Sumilex resin 650" (a 30% aqueous solution having a solid content) sold by Sumika Chemtex Co., Ltd., was dissolved to prepare a polyvinyl alcohol-based adhesive.

After the saponification treatment was performed on the side opposite to the side on which the antiglare layer A of the antiglare film A was formed, 10 μm of the polyvinyl alcohol-based adhesive prepared as described above was applied by a screw extrusion coater, and then attached thereto. A polyvinyl alcohol-iodine polarizing film obtained in advance. In addition, the polyvinyl alcohol-based adhesive prepared as described above was applied to the surface of the polyvinyl alcohol-iodine polarizing film opposite to the surface to which the antiglare film was bonded, and then saponified. A transparent protective film (KC4UE, thickness 40 μm, R ₀ = 0.7 nm, R _th = -0.1 nm) developed by Konica Minolta Opto Co., Ltd. having a thickness of 40 μm was applied. Thereafter, it was dried at 80 ° C for 5 minutes, and further cured at room temperature for one day to obtain an anti-glare polarizing plate A.

(E) Production of the back side polarizing plate

The polycarbonate film was subjected to thickness orientation by a method described in JP-A-7-230007 to prepare a retardation film having a three-dimensional orientation of R ₀ = 178 nm and R _th = -34.2 nm. The retardation film is bonded to a polarizing plate (trade name "Sumikalan SRW842A", which is a protective film made of triacetyl cellulose on both sides of a polarizing film of polyvinyl alcohol-iodine, via a binder, Sumitomo Chemical ( Co., Ltd. was developed to produce a back side polarizing plate with R _th = 55 nm and R ₀ = 1 nm). At this time, the retardation axis of the retardation film and the absorption axis of the polarizing plate are arranged to be perpendicular to each other.

(F) Production of liquid crystal display device

The polarizing plate was peeled off from the liquid crystal cell of a commercially available television set (W32L-H9000, manufactured by Hitachi, Ltd.) equipped with an IPS mode liquid crystal display element (ie, an image display element), on the back side of the liquid crystal cell ( The back side polarizing plate and the anti-glare polarizing plate A on the front side (recognition side) of the liquid crystal cell are both adhered to the absorption axis of the polarizing plate of the liquid crystal television. In a consistent manner, they were bonded together via an adhesive layer to form a liquid crystal panel. Next, the liquid crystal panel is assembled by a configuration of a backlight/light diffusing plate/liquid crystal panel to produce a liquid crystal display device A (that is, an image display device).

<Comparative column 41>

The surface of an aluminum roller (JIS A5056) having a diameter of 300 mm was mirror-polished, and a sandblasting device (developed by Fujifilm Co., Ltd.) was used. The surface of the polished aluminum was pressed at a pressure of 0.1 MPa (gauge pressure, the same below). ), the amount of beads used is 8 g/cm ² (the surface area of the roll is on average per 1 cm ² , the same applies hereinafter), and the zirconia beads TZ-SX-17 (developed by Tosoh Co., Ltd., average particle diameter: 20 μm), The surface is covered with irregularities. The obtained aluminum roll having irregularities was subjected to electroless nickel plating to prepare a mold B. At this time, the thickness of the electroless nickel plating was set to 15 μm. An anti-glare film B was produced in the same manner as in Example 41 except that the obtained mold B was used. Further, an anti-glare polarizing plate B and a liquid crystal display device B were produced in the same manner as in Example 41 except that the anti-glare film B was used.

Fig. 17 shows a power spectrum G ² (f) obtained from the pattern used in the production of the anti-glare film A. It is understood that the power spectrum of the pattern used in the production of the anti-glare film A does not have a maximum value when the spatial frequency is more than 0 μm ^-1 and 0.04 μm ^-1 or less, and has a maximum value when it is more than 0.04 μm ^-1 and 0.08 μm ^-1 or less. .

Further, Fig. 33 shows the second-order derivative function d ² Ψ ² (f)/df ² of the power spectrum of the complex amplitude calculated from the elevations of the anti-glare films A and B. As can be seen from Fig. 33, the one-dimensional power spectrum of the complex amplitude calculated from the elevation of the anti-glare film A has two inflection points in the range of a spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less, but The one-dimensional power spectrum of the complex amplitude calculated by the elevation of the glare film B is not a power spectrum having two inflection points in the range of a spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less.

The anti-glare films A and B and the liquid crystal display devices A and B produced in Example 41 and Comparative Example 41 are shown in Table 4 as a result of performing the above evaluations.

As is clear from the results shown in Table 4, all of the image display devices A (Example 41) satisfying the requirements of the fourth invention did not cause glare at all, showing sufficient anti-glare properties, and no fading occurred. Higher contrast and wide field of view characteristics. On the other hand, the image display device B (Comparative Example 41) using the anti-glare film B (see Fig. 33) which does not satisfy the requirements of the fourth invention shows a tendency to cause glare.

1. . . Anti-glare film

2. . . Bumps formed on the surface of the film

3. . . Film projection surface

5. . . Main normal direction of the film

6. . . Normal of local location

6a to 6d. . . Polyhedral normal vector

7. . . Mold base

8. . . Surface of the substrate ground by the grinding step

9. . . Photosensitive resin film

10. . . Exposed area

11. . . Unexposed area

12. . . Mask

13. . . Unmasked area

15. . . First surface uneven shape (concavo-convex shape of the surface of the substrate for the mold after the first etching step)

16. . . Second surface uneven shape (concave-convex shape of the surface of the substrate for the mold after the second etching step)

17. . . Chrome plating

18. . . Chrome-plated surface

20. . . Elevation datum

twenty one. . . Highest elevation

40. . . Photomask unit

41. . . Chrome opaque pattern of the mask

42. . . Opening of the mask

43. . . Mask

45. . . Light box

46. . . light source

47. . . glass plate

49. . . Flashing observation position

50. . . Diffuser

100. . . Anti-glare layer

101. . . Transparent support

102, 103, 104. . . Transparent protective film

110. . . Liquid crystal cell

111, 112. . . Box substrate

120. . . (front side) polarizing film

121. . . (back side) polarizing film

130. . . Phase difference film

413. . . Liquid crystal layer

414. . . Liquid crystal molecule

Fig. 1 is a perspective view schematically showing the surface of the anti-glare film of the first to fourth inventions.

Fig. 2 is a schematic view showing the relationship between the elevation h(x, y) of the fine uneven surface and the elevation reference surface and the highest elevation surface.

Fig. 3 is a schematic diagram showing a state in which the function h(x, y) indicating the elevation is discretely obtained.

Fig. 4 is a view showing the elevation of the fine uneven surface of the anti-glare film of the first to fourth inventions by a two-dimensional discrete function h(x, y).

Fig. 5 is a schematic diagram for explaining a method of averaging the two-dimensional power spectrum Ψ ² (f _x , f _y ) from the distance f from the origin of the frequency space.

Fig. 6 is a view showing a one-dimensional power spectrum Ψ ² (f) obtained by performing discrete Fourier transform on the complex amplitude calculated from the two-dimensional function h(x, y) shown in Fig. 3.

Fig. 7 is a view showing a state in which linear interpolation is performed on the one-dimensional power spectrum Ψ ² (f) of the complex amplitude.

Fig. 8 is a view showing a one-dimensional power spectrum obtained by linearly interpolating the one-dimensional power spectrum Ψ ² (f) of the complex amplitude of Fig. 6 as a discrete function of every 0.008 μm ^-1 . Ψ ² (f) diagram.

Fig. 9 is a view showing a second-order derivative function d ² Ψ ² (f)/df ² of the one-dimensional power spectrum Ψ ² (f) of the complex amplitude of Fig. 8.

Fig. 10 is a graph showing the relationship between the intensity of the one-dimensional power spectrum Ψ ² (f) having a spatial frequency of 0.03 μm ^-1 and the reflectance sharpness.

Fig. 11 is a plan view showing a unit of a pattern for evaluation of a glare.

Fig. 12 is a schematic cross-sectional view showing a state in which the glare evaluation is performed.

Fig. 13 is a graph showing the relationship between the intensity of the one-dimensional power spectrum Ψ ² (f) having a spatial frequency of 0.02 μm ^-1 and the evaluation result of the glare.

Fig. 14 is a schematic view for explaining a method of measuring the inclination of the fine uneven surface.

Fig. 15 is a graph showing an example of a histogram of the inclination distribution of the minute surface of the fine uneven surface of the anti-glare film.

Fig. 16 is a view schematically showing image data which is a pattern used for producing the anti-glare films of the first to fourth aspects of the present invention.

Fig. 17 is a view showing a power spectrum G ² (f) obtained by performing discrete Fourier transform on the pattern shown in Fig. 16.

Fig. 18 is a view schematically showing a preferred example of the first half of the method for producing a mold which is preferably used in the production of the anti-glare film of the first to fourth embodiments of the present invention.

Fig. 19 is a view schematically showing a preferred example of the latter half of the method for producing a mold which is preferably used in the production of the anti-glare film of the first to fourth embodiments of the present invention.

Fig. 20 is a view showing a pattern used in the production of the mold of the fourth embodiment.

Fig. 21 is a view showing a pattern used in the production of a mold of Comparative Example 1.

Fig. 22 is a view showing a pattern used in the production of the mold of the second embodiment.

Fig. 23 is a view showing a power spectrum G ² (f) of the pattern shown in Figs. 20 to 22 .

Fig. 24 is a view showing the second-order derivative function d ² Ψ ² (f)/df ² of the one-dimensional power spectrum of the complex amplitude calculated from the elevations of the anti-glare films of Examples 1 to 4.

Fig. 25 is a view showing the second-order derivative function d ² Ψ ² (f)/df ² of the one-dimensional power spectrum of the complex amplitude calculated from the elevation of the anti-glare film of Comparative Examples 1 to 3.

Figure 26 is a diagram showing the second-order derivative function d ² Ψ ² (f)/ of the one-dimensional power spectrum of the complex amplitude calculated from the elevations of the anti-glare films A to C used in Example 21, Comparative Example 21, and Comparative Example 22. Figure of df ² .

Figure 27 is a schematic cross-sectional view showing an example of a liquid crystal display device of the second invention.

Fig. 28 is a schematic cross-sectional view showing another example of the liquid crystal display device of the second invention.

Fig. 29 is a schematic cross-sectional view showing still another example of the liquid crystal display device of the second invention.

Fig. 30 is a schematic cross-sectional view showing still another example of the liquid crystal display device of the second invention.

Fig. 31 is a schematic cross-sectional view showing still another example of the liquid crystal display device of the second invention.

Figure 32 is a schematic cross-sectional view showing still another example of the liquid crystal display device of the second invention.

Figure 33 is a diagram showing the second-order derivative function d ² Ψ ² of the one-dimensional power spectrum of the complex amplitude calculated from the elevations of the anti-glare film A used in Examples 31 and 41 and the anti-glare film B used in Comparative Examples 31 and 41. (f) / df ² map.

Figure 34 is a schematic cross-sectional view showing an example of a liquid crystal display device of the third invention.

Figure 35 is a schematic cross-sectional view showing another example of the liquid crystal display device of the third invention.

Figure 36 is a schematic cross-sectional view showing still another example of the liquid crystal display device of the third invention.

Figure 37 is a schematic cross-sectional view showing an example of a liquid crystal display device of a fourth invention.

Figure 38 is a schematic cross-sectional view showing another example of the liquid crystal display device of the fourth invention.

1. . . Anti-glare film

5. . . Main normal direction of the film

20. . . Elevation datum

twenty one. . . Highest elevation

Claims (14)

An anti-glare film comprising a transparent support and an anti-glare layer, wherein the anti-glare layer is formed on the transparent support and has a fine uneven surface having fine irregularities on the opposite side of the transparent support, characterized in that the internal haze It is 1% or less, and the surface haze is 0.4% or more and 10% or less, and is incident from the main normal direction of the average surface of the fine uneven surface, and includes the point having the highest elevation from the fine uneven surface and the above-mentioned fineness An imaginary plane parallel to the average surface of the concave-convex surface, that is, a plane wave having a wavelength of 550 nm emitted from the highest elevation surface, and a complex amplitude of the highest elevation surface is calculated from the elevation of the fine uneven surface and the refractive index of the anti-glare layer. The one-dimensional power spectrum of the complex amplitude is expressed as a graph showing the intensity of the spatial frequency, and has two inflection points in a range of a spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less. . The anti-glare film according to claim 1, wherein the second-order derivative function of the one-dimensional power spectrum of the complex amplitude and the spatial frequency is positive when the spatial frequency is 0.024 μm ^-1 . The anti-glare film according to the first or second aspect of the invention, wherein the ratio of the micro-faces having an inclination angle of 5 or more in the fine uneven surface is less than 10%. A liquid crystal display device comprising: a liquid crystal cell in which liquid crystal is sealed between a pair of mutually parallel cassette substrates, the liquid crystal being oriented in a substantially vertical direction with respect to the cassette substrate in the vicinity of the cassette substrate in a voltage-free application state; a side polarizing film disposed on an identification side of the liquid crystal cell; a rear side polarizing film disposed on an opposite side of the identification side of the liquid crystal cell; and at least one retardation film on the back side polarizing film and the liquid crystal cell And/or disposed between the front side polarizing film and the liquid crystal cell; the anti-glare film includes a transparent support and an anti-glare layer, wherein the anti-glare layer is formed on the transparent support and is provided on the transparent support The anti-glare film has a fine uneven surface having a fine concavity and convexity, and the anti-glare film is disposed on the opposite side of the surface of the front-side polarizing film facing the liquid crystal cell so that the anti-glare layer is the most recognizable side. The anti-glare film has an internal haze of 1% or less and a surface haze of 0.4% or more and 10% or less, and is related to the fine uneven surface. a plane wave having a wavelength of 550 nm emitted from a virtual plane having the highest elevation and a plane parallel to the average plane of the fine uneven surface, and having a wavelength of 550 nm, which is the highest elevation surface The complex amplitude is calculated from the elevation of the fine uneven surface and the refractive index of the antiglare layer, and the one-dimensional power spectrum of the complex amplitude is expressed as the intensity of the spatial frequency, and the spatial frequency is 0.032 μm ^-1 or more. And in the range of 0.064 μm ^-1 or less, there are two inflection points. The liquid crystal display device according to claim 4, wherein the retardation film has an in-plane retardation value R ₀ of 50 nm or more and 80 nm or less, and a thickness direction phase difference R _th of the retardation film is 120 nm or more. And below 250nm. A liquid crystal display device comprising: a liquid crystal cell in which twisted nematic liquid crystal is sealed between a pair of mutually parallel cassette substrates; a front side polarizing film disposed on an identification side of the liquid crystal cell; and a back side polarizing film; Arranging on the opposite side of the identification side of the liquid crystal cell; the optically anisotropic layer is disposed between the back side polarizing film and the liquid crystal cell, and at least one of the front side polarizing film and the liquid crystal cell An anti-glare film comprising a transparent support and an anti-glare layer, wherein the anti-glare layer is formed on the transparent support and has a fine uneven surface having fine irregularities on the opposite side of the transparent support, and the anti-glare The film is disposed on the opposite side of the surface of the front side polarizing film facing the liquid crystal cell so that the antiglare layer is the most recognizable side, and the internal haze of the antiglare film is 1% or less. The surface haze is 0.4% or more and 10% or less, and is incident on the main normal direction of the average surface of the fine uneven surface, and includes the highest level from the fine uneven surface. a high-point, a plane wave parallel to the average surface of the fine uneven surface, that is, a plane wave having a wavelength of 550 nm emitted from the highest elevation surface, and the complex amplitude of the highest elevation surface is obtained from the elevation of the fine uneven surface and the refractive index of the anti-glare layer. The graph obtained when the one-dimensional power spectrum of the complex amplitude is expressed as the intensity of the spatial frequency has two inflection points in a range of a spatial frequency of 0.032 μm ^-1 or more and 0.064 μm ^-1 or less. The liquid crystal display device according to claim 6, wherein the optically anisotropic layer is disposed between the back side polarizing film and the liquid crystal cell and between the front side polarizing film and the liquid crystal cell. The liquid crystal display device according to claim 6, wherein the optically anisotropic layer is optically negative or positive uniaxial, and an optical axis thereof is inclined by 5 to 50° from a normal direction of the film. Layer. A liquid crystal display device comprising: a liquid crystal cell in which liquid crystal is sealed between a pair of mutually parallel cassette substrates, the liquid crystal being oriented in substantially the same direction parallel to the cassette substrate; and a front side polarizing film disposed in the liquid crystal cell The front side polarizing film is disposed on the opposite side of the recognition side of the liquid crystal cell; the anti-glare film includes a transparent support and an anti-glare layer, and the anti-glare layer is formed on the transparent support and has The anti-glare film has a fine uneven surface on the opposite side of the transparent support, and the anti-glare film is disposed on the opposite side of the surface of the front-side polarizing film facing the liquid crystal cell so that the anti-glare layer is the most recognizable side. The anti-glare film has an internal haze of 1% or less and a surface haze of 0.4% or more and 10% or less, and is incident on the fine normal groove from the main normal direction of the average surface of the fine uneven surface. a plane wave having a wavelength of 550 nm emitted from a virtual plane having the highest elevation point and parallel to the average surface of the fine uneven surface, that is, the highest elevation surface. The complex amplitude of the highest elevation surface is calculated from the elevation of the above-mentioned fine concave-convex surface and the refractive index of the anti-glare layer, and the one-dimensional power spectrum of the complex amplitude is expressed as the intensity of the spatial frequency, and the spatial frequency is 0.032. range of less than 0.064μm ^{-1 -1 μm} having two inner fold points. The liquid crystal display device according to claim 9, wherein the front side polarizing film is directly bonded to the front side surface of the liquid crystal cell. The liquid crystal display device according to claim 9, wherein the liquid crystal cell side surface of the front side polarizing film has a transparent protective film having a thickness direction phase difference R _th of -10 nm to +40 nm In the range. The liquid crystal display device according to claim 11, wherein the transparent protective film is made of a cellulose acetate resin or a norbornene resin. The liquid crystal display device according to any one of claims 4 to 12, wherein the second-order derivative function of the one-dimensional power spectrum of the complex amplitude and the spatial frequency is positive when the spatial frequency is 0.024 μm ^-1 . The liquid crystal display device according to any one of the fourth aspect of the invention, wherein the ratio of the micro-faces having an inclination angle of 5 or more in the fine uneven surface is less than 10%.