JP6706088B2 - Display device, protective film used therefor, method of manufacturing display device, and method of using protective film - Google Patents

Description

The present invention relates to a display device such as a liquid crystal display device, a plasma display device, an EL display device, a cathode ray tube display device, and an LED display device, and more particularly to a display device provided with a protective film for preventing glare (sparkle).

In a display device such as a liquid crystal display device, a plasma display device, an EL display device, a cathode ray tube display device, an LED display device, etc., in recent years, the definition of an image has become higher, and the pixel pitch of the display screen (in other words, the size of one pixel). ) Is getting smaller.
In addition, many display devices include a protective film having a fine uneven surface, such as an antiglare film, in order to make the image easy to see.
In a high-definition display device, fine unevenness of a protective film and light from pixels of a display screen interfere with each other, resulting in moire image interference fringes, and a glare phenomenon in which an image is rough and difficult to see.

Various proposals have been made to suppress the generation of glare.

In the technology described in Patent Document 1, in a Newton-ring prevention sheet used for a touch panel, the average particle diameter of particles in the Newton-ring prevention layer and the coefficient of variation are adjusted to prevent glare.

Patent Document 2 discloses a method for quantitatively evaluating variations in brightness due to glare. Specifically, in this evaluation method, a display image is captured by a CCD camera, the captured image is Fourier-transformed, regular periodic components generated by pixels of the display image are removed, and then inverse Fourier transform is performed.

Patent Document 3 discloses an antiglare film glare evaluation device for objective evaluation.

JP, 2005-265864, A JP, 2009-175041, A Japanese Patent No. 3766342

Since the degree of glare caused by the combination of the protective film and the light emitting body varies depending on the combined light emitting body, even if only the protective film is improved as in Patent Document 1, it is not possible to suppress the generation of glare in any display device.

Further, Patent Documents 2 and 3 disclose evaluating the presence or absence of glare and the degree thereof, but disclose a specific configuration for realizing glare prevention in a combination of a light-emitting body and a protective film. Absent. Further, the evaluation methods described in Patent Documents 2 and 3 are based on analyzing the luminance value of the data obtained from the captured image. However, the evaluation based on the brightness value does not always coincide with the visual result in a high definition display device.

An object of the present invention is to prevent glare in a display device in which a light-emitting body and a protective film are combined by setting a glare index and a variation width determined by using a predetermined glare evaluation method within a predetermined range.

The display device of the present invention includes a light-emitting body whose surface is divided by a plurality of pixels, and a protective film disposed on the light-emitting surface of the light-emitting body, and is an evaluation method including the following steps AF. When evaluated, the glaring index is 3.0 or less and the variation width is 1.1 or less:
Step A: a step of obtaining a color image data by photographing the light emitting body through the protective film by the photographing means while the light emitting body is turned on,
Step B: a step of performing a Fourier transform on the color image data obtained in step A, removing frequency components corresponding to the array of pixels from the data after the Fourier transform, and then performing an inverse Fourier transform,
Step C: a step of calculating a standard deviation value of RGB values of the data obtained in step B and an average value thereof,
Step D: Steps A to D are performed without disposing the protective film on the luminous body, and an average value of standard deviation values of RGB values is calculated as a reference value,
Step E: a step of calculating the deviation amount between the average value of the standard deviation values of the RGB values calculated in step C and the reference value calculated in step D as a glare index, and step F: the RGB values calculated in step C. A step of calculating a difference between standard deviations as a variation width.

Further, according to one aspect of the display device of the present invention, the luminous body has a pixel density of 300 pixels/inch (PPI) or more.

Further, according to one aspect of the display device of the present invention, the protective film includes an uneven layer including a matting agent and a binder resin and having unevenness on the surface.

Further, according to one aspect of the display device of the present invention, the uneven layer of the protective film contains the matting agent in an amount of 0.5 to 15 parts by weight based on 100 parts by weight of the binder resin.

In addition, the protective film of the present invention has an in-plane sectioned by a plurality of pixels, a light-emitting body having a pixel density of 300 pixels/inch (PPI) or more, and a light-emitting surface of the light-emitting body. It is used for a display device provided with a protective film arranged, and has a glaring index of 3.0 or less and a variation width of 1 when evaluated by an evaluation method including the following steps A to F (referred to as "glare evaluation method"). .1 or less:
Step A: a step of obtaining a color image data by photographing the light emitting body through the protective film by the photographing means while the light emitting body is turned on,
Step B: a step of performing a Fourier transform on the color image data obtained in step A, removing frequency components corresponding to the array of pixels from the data after the Fourier transform, and then performing an inverse Fourier transform,
Step C: a step of calculating a standard deviation value of RGB values of the data obtained in step B and an average value thereof,
Step D: Steps A to C are performed without disposing the protective film on the light emitter, and a step of calculating an average value of standard deviation values of RGB values as a reference value,
Step E: a step of calculating the deviation amount between the average value of the standard deviation values of the RGB values calculated in step C and the reference value calculated in step D as a glare index, and step F: the RGB values calculated in step C. A step of calculating a difference between standard deviations as a variation width.
In addition, a method of manufacturing a display device including a protective film and a light-emitting body whose surface is divided into a plurality of pixels according to the present invention,
Disposing the protective film on the light emitting surface of the light emitting body,
A step of performing a glare evaluation method,
In the step of disposing the protective film, a protective film having a glaring index of 3.0 or less and a variation width of 1.1 or less when evaluated in the glaring evaluation method is used as the protective film.
In addition, the method of using the protective film of the present invention is evaluated by a glaring evaluation method, and a protective film having a glaring index of 3.0 or less and a variation width of 1.1 or less is classified by a plurality of pixels in the plane. It is used for a display device provided with the luminous body.

INDUSTRIAL APPLICABILITY The present invention can provide a display device that prevents glare in a display device in which a light-emitting body and a protective film are combined by setting a glare index and a variation width determined using a predetermined glare evaluation method within a predetermined range.

FIG. 3 illustrates a display device which is an example of the present invention. Sectional drawing of the display apparatus which is another example of this invention. Sectional drawing of the display apparatus which is another example of this invention. Sectional drawing of the display apparatus which is another example of this invention. Sectional drawing of the display apparatus which is another example of this invention. The figure explaining an example of the screen structure (pixel structure) of a light-emitting body. (A) Sectional drawing which shows an example of the protective film used for the display apparatus of this invention, (b) and (c) Sectional drawing which shows the other example of the protective film used for the display apparatus of this invention. Flow chart for calculating glare index and variation width Explanatory drawing showing an outline of a glare evaluation device

Hereinafter, embodiments of the display device of the present invention will be described.

The display device 24 of the present embodiment includes the light-emitting body 23 and the protective film 1, and has a scintillation index of 3.0 or less and a scatter width of 1.1 or less measured by a predetermined scintillation evaluation method.

First, the configuration of the display device of this embodiment will be described.

The display device 24 of the present embodiment basically includes a light emitting body 23 and a protective film 1, as shown in FIG. In the display device 24, the protective film 1 is arranged, for example, on the surface of the light emitting body 23 with the uneven layer 2 as the surface (the side 10 on which the viewer of the display screen observes).

As an example of another embodiment of the display device, as shown in FIGS. 2 to 5, the display device 24 can be configured to include the surface member 22, and the protective film 1 is provided on the surface member 22.

Examples of the surface member 22 include a protective plate 22a, a touch panel 22b, a polarizing plate 22c, and a combination of two or more of these. In this embodiment, the protective film 1 is included in at least a part of the surface members 22 (22a, 22b, 22c).

The protection plate 22a can be formed of, for example, a transparent resin plate represented by an acrylic resin plate. The thickness of the protective plate 22a is usually about 0.1 to 2.0 mm.

The method of the touch panel 22b is not particularly limited, and it can be configured by, for example, a resistive film type touch panel, a capacitance type touch panel, or the like.

For example, the surface member 22 protecting plate 22a, when the touch panel 22b or polarizer 22c,, as shown in FIG. 2, a on the light emitting surface of the light emitter 23, the surface of the surface member 22 (22a, 22b, 22c) The display device 24 may be configured by laminating the protective film 1 on the side.

Further, as shown in FIG. 3, for example, when the surface member 22 is the protective plate 22a or the touch panel 22b, the display device 24 is configured by laminating the protective film 1 on the back side of the surface member 22 (22a, 22b). You can also do it. In this case, the protective film 1 is arranged so that the uneven layer 2 of the protective film 1 faces the light emitting body 23.

In addition, as shown in FIG. 4, when the thickness of the protective film 1 can be increased, the display device 24a may be configured by providing the protective film 1 itself as the protective plate 22a on the light emitting body 23.

Further, as shown in FIG. 5, the display device 24b may be configured by using the protective film 1 itself as a member of the outermost surface, the middle (not shown), and the rearmost surface (not shown) of the touch panel 22b.

The light emitter 23 has a screen structure of a dot matrix display system, and has a function of displaying an image by a large number of pixels arranged vertically and horizontally. Examples of such a light emitter 23 include a liquid crystal display device and a plasma display device. Examples include display devices, EL display devices, cathode ray tube display devices, and LED display devices.

FIG. 6 shows a structure of a liquid crystal display device as an example of the light emitting body 23. The light-emitting body 23 includes, for example, in the LCD panel 84, a plurality of pixels 85 (pixels) formed in a grid using wirings from the X driver (data driver) 81 and wirings from the Y driver (address driver) 82. : Pixel). The definition (PPI (pixels per inch)) is determined by the size of the pixel pitch 83.
Since the generation of glare becomes remarkable as the definition becomes higher, the problem of glare is more serious in the light-emitting body 23 having a higher PPI due to the higher definition than in the light-emitting body 23 having a low PPI. Therefore, the present invention is suitably applied to a display device using a light emitting body having a high PPI. Specifically, the light emitter 23 having pixels of 100 PPI or more, 200 PPI or more, 250 PPI or more, 300 PPI or more, or 325 PPI or more is targeted.

Next, an outline of the protective film 1 of this embodiment used for the display device 24 will be described.
The protective film 1 has a glare prevention function, and may further have an antiglare function or a Newton's ring prevention function depending on the arrangement of the protective film 1.

As shown in FIGS. 7A to 7C, the protective film 1 includes an uneven layer 2. The concavo-convex layer 2 may be laminated on one surface of the support 5 (FIG. 7A) or on both sides of the support 5 (FIG. 7B). It may be a layer ((c) in FIG. 7).
Further, when the uneven layer 2 is laminated on one surface of the support 5 (FIG. 7A), the back coat layer, the antistatic layer, Alternatively, an adhesive layer (not shown) may be provided. Alternatively, a back coat layer, an antistatic layer, or an adhesive layer (not shown) may be provided on the surface opposite to the uneven surface of the uneven layer 2 single layer (FIG. 7C). The uneven layer 2 is formed of a binder resin 4 and a matting agent 3. Alternatively, it is formed by a roughening method such as a sandblasting method, an embossing method, a shaping method using a mold, an etching method, or the like. Details will be described later.

Next, a glaring evaluation method for determining the glaring index and the variation width of the display device having the above configuration will be described with reference to FIG. The glare evaluation method mainly includes a step A (S1 in FIG. 8) for obtaining color image data by photographing the light-emitting body 23 through the protective film 1 by the photographing means while the light-emitting body 23 is turned on, and step A. The obtained color image data is Fourier-transformed, the frequency component corresponding to the pixel array is removed from the Fourier-transformed data, and then the inverse Fourier transform is performed in step B (S2 in FIG. 8) and step B. perform step C (S3 in FIG. 8) to calculate the standard deviation and the average value of the RGB values of the data, the step C from step a not place a protective film 1 to the light emitting element 23, the standard deviation of the RGB values A step D (S4 in FIG. 8) in which the average value of the values is calculated as a reference value, and a deviation amount between the average value of the standard deviation values of the RGB values calculated in step C and the reference value calculated in step D is determined by a glare index. And step F (S5 of FIG. 8) and step F (S6 of FIG. 8) of calculating the difference between the standard deviations of the RGB values calculated in step C as the variation width.

Such a glare evaluation method can be measured using, for example, a glare evaluation apparatus 60 shown in FIG. The glare evaluation device 60 mainly includes a photographing unit 61 for color-imaging an image displayed on the display device 24, and an image data processing unit 63 for processing a color image obtained by imaging to calculate a glare index or the like. Equipped with. If necessary, the glare evaluation apparatus can further include an image display unit 64 for displaying the image processed by the image data processing unit 63.

Further, step A to step F will be described in detail.

(Step A)
As shown in FIG. 9, a display device 24 is placed below the image capturing means 61 so that the image can be captured at a vertical position on the light emitting surface of the light emitting body 23. Except for obtaining the reference value (Y _ref ) of the average values of the standard deviations of RGB described below, the display device 24 uses the uneven layer 2 as the surface (on the side of the photographing unit 61) and on the light emitting surface of the light emitting body 23. The protective film 1 is disposed on the.

In the display device 24 having the protective film 1, a uniform single color is generated from the light source (not shown) of the light emitter 23. For example, it is possible to perform white display by setting the display color to "#FFFFFF" in hexadecimal display with the light amount of the light source set to the maximum. Subsequently, the image displayed by the light-emitting body 23 with a single color from the light source is color-photographed by the photographing means 61 through the protective film 1 to acquire color image data. At that time, it is preferable that the resolution of the photographing means 61 is smaller than that of the light emitting body 23.

(Step B)
Next, the image data processing unit 63 extracts an arbitrary colorimetric area from the color image data acquired by the photographing unit 61. As the color measurement area, for example, a color measurement area of 500 pixels×500 pixels can be extracted. The image data processing unit 63 performs a two-dimensional Fourier transform process on the extracted region. By this processing, a two-dimensional Fourier spectrum can be obtained. Subsequently, the image data processing unit 63 removes the high frequency component, which is a regular periodic component generated by the pixels of the image displayed on the light emitting body 23, from each of the obtained two-dimensional Fourier spectra.

By performing such processing, it is possible to remove from the two-dimensional Fourier spectrum a specific pattern (such as a grid pattern) generated from the gaps between the pixels or the wiring. In addition, highly accurate evaluation can be performed as compared with the conventional glare evaluation method that removes only the frequencies with bright lines.

After that, the image data processing means 63 performs an inverse Fourier transform process on the two-dimensional Fourier spectrum from which the high frequency component has been removed. By performing such a process, it is possible to acquire an image in a state where a specific pattern that is redundant for evaluation is removed.

(Step C)
Then, in the present embodiment, the image data obtained by the inverse Fourier transform process is processed by the image data processing means 63. This data processing is data processing for calculating a glare evaluation value.

As the flow of data processing, first, from image data subjected to inverse Fourier transform, R value, G value, B value of each pixel (pixel), standard deviation of R value, standard deviation of G value, standard of B value Calculate the deviation.
Next, the average value of the RGB standard deviation values is calculated from the calculated RGB standard deviation values. If the standard deviation values of each RGB are X _R , X _G , and X _B , the average value (Y) of the standard deviation values of RGB can be calculated using the following formula.
[Equation 1]
Y=(X _R +X _G +X _B )/3 (Formula 1)

(Step D)
In the display device 24 in which the protective film 1 is not arranged on the light emitting surface of the light emitting body 23, the above steps A to C are performed, and the R value, G value, B value, and R value of each pixel (pixel) are executed. The standard deviation of, the standard deviation of the G value, and the standard deviation of the B value are calculated. The average value of the RGB standard deviation values is calculated as a reference value from the calculated RGB standard deviation values. If the standard deviation values of each RGB are X _Rref , X _Gref , and X _Bref , the reference value (Y _ref ) that is the average value of the RGB standard deviation values is as follows.
[Equation 2]
Y _ref =(X _Rref +X _Gref +X _Bref )/3 (Equation 2)

(Step E)
The deviation amount between the average value of the RGB standard deviation values calculated in step C (Y) and the reference value of the average value of the RGB standard deviation values calculated in step D (Y _ref ) is calculated as a glare index (S). .. For example, the glare index (S) is obtained by calculating the difference between Y and Y _ref as shown in the following formula.
[Equation 3]
S=Y-Y _ref (Equation 3)

The glaring index (S) is an index indicating how the variations in the light emission of the respective RGB pixels match, as compared with the display device 24 without the protective film 1 and the display device 24 with the protective film 1.
Therefore, the larger the difference value between the Y value of the display device 24 having the protective film 1 and the Y _ref value of the display device 24 excluding the protective film 1, the greater the degree of glare, and the smaller the evaluation value, the smaller the degree of glare. Become.

In the display device 24 of the present embodiment, the glare index measured by the above-described glare evaluation method is 3.0 or less, preferably 2.5 or less, more preferably 2.0 or less. By setting the glare index to 3.0 or less, glare can be prevented even in the display device 24 using the light emitting body 23 having various PPIs.

(Step F)
Next, using the standard deviation of the RGB values calculated from step C, the difference between the standard deviations of the RGB values is calculated as the variation width (D). Since the variation width is an index that indicates the degree of variation in the light emission of each of the RGB pixels within the same plane, the accuracy of the glare evaluation can be increased by determining the variation width.
Specifically, when the maximum value of the standard deviations X _R , X _G , and X _B of the RGB values calculated in step C is X _{max and the} minimum value is X _min , the maximum value (X _max ) and the minimum value are obtained. The difference from the value (X _min ) is calculated as the variation width (D). For example, the variation width (D) can be calculated using the following formula.
[Formula 4]
D=X _max −X _min (Equation 4)

The display device 24 of this embodiment has a variation width (D) of 1.1 or less, preferably 1.0 or less, and more preferably 0.5 or less. By setting the ratio to 1.1 or less, the accuracy of the glare evaluation can be improved as compared with the visual glare evaluation.

In the above-described evaluation method, the RGB color system is used as the index indicating the color, but the XYZ color system may be used.

When the evaluation device 60 includes the image display means 64 (see FIG. 9), the image acquired in step B is displayed on the image display means 64 at the output destination so that the chromaticity can be visually checked on the image display means 64. -It is possible to check the variation in brightness.

A specific configuration of the protective film 1 for obtaining the above glare prevention effect and the like will be described. The concavo-convex layer 2 which is a main component of the protective film 1 contains a binder resin 4 and a matting agent 3 (see FIG. 7). Examples of the binder resin 4 include ionizing radiation curable resin, thermosetting resin and thermoplastic resin.

The uneven layer 2 is composed of a cured product of a curable composition (curable resin precursor), and has a plurality of convex portions caused by the matting agent 3 on the surface. Here, the cured product is a curable resin as a main curing agent, and a curing aid such as a polymerization initiator, a polymerization accelerator (such as an ultraviolet sensitizer) or a curing agent, which is necessary for curing the curable resin. Is used in the concept that also includes.

As the ionizing radiation curable resin, a resin that is crosslinked and cured by irradiation with ionizing radiation (ultraviolet ray or electron beam) is used. As such a material, it is possible to use one kind or a mixture of two or more kinds such as a cationic photopolymerizable resin capable of cationic photopolymerization, a photopolymerizable prepolymer capable of radical photopolymerization or a photopolymerizable monomer. it can.

Examples of the cationic photopolymerizable resin include epoxy resins such as bisphenol epoxy resin, novolac epoxy resin, alicyclic epoxy resin, and aliphatic epoxy resin, and vinyl ether resin.

As the photopolymerizable prepolymer, an acrylic prepolymer having two or more acryloyl groups in one molecule and having a three-dimensional network structure by being crosslinked and cured is particularly preferably used. As the acrylic prepolymer, urethane acrylate, polyester acrylate, epoxy acrylate, melamine acrylate, polyfluoroalkyl acrylate, silicone acrylate and the like can be used. Further, although these acrylic prepolymers can be used alone, it is preferable to add a photopolymerizable monomer in order to improve the crosslinkability and the hardness of the functional layer.

Examples of the photopolymerizable monomer include monofunctional acrylic monomers such as 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and butoxyethyl acrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol. One of difunctional acrylic monomers such as diacrylate, polyethylene glycol diacrylate, hydroxypivalic acid ester neopentyl glycol diacrylate, and polyfunctional acrylic monomers such as dipentaerythritol hexaacrylate, trimethylpropane triacrylate, pentaerythritol triacrylate, etc., or Two or more kinds are used.

The ionizing radiation-curable resin is, in addition to the above-mentioned photo-cationic polymerizable resin, photo-polymerizable prepolymer or photo-polymerizable monomer, when it is cured by ultraviolet irradiation, it is a curing assistant such as a photopolymerization initiator or an ultraviolet sensitizer. It is preferable to include an agent. As the photopolymerization initiator, acetophenones, benzophenones, Michler's ketone, benzoin, benzylmethyl ketal, benzoyl benzoate, α-acyl oxime esters, thioxanthones, and other radical photopolymerization initiators, onium salts, sulfonates, and organometallics. Examples include photocationic polymerization initiators such as complexes. Examples of the UV sensitizer include n-butylamine, triethylamine, tri-n-butylphosphine and the like.

In addition, the photopolymerization accelerator can reduce the polymerization trouble due to air at the time of curing to accelerate the curing rate, and examples thereof include p-dimethylaminobenzoic acid isoamyl ester and p-dimethylaminobenzoic acid ethyl ester. Can be mentioned.

Further, as the ionizing radiation curable resin, an ionizing radiation curable organic-inorganic hybrid resin may be used. Ionizing radiation-curable organic-inorganic hybrid resin (hereinafter sometimes simply abbreviated as "organic-inorganic hybrid resin") is an organic substance and an inorganic substance, which is different from the old composites represented by glass fiber reinforced plastic (FRP). The method of mixing is intimate, and the state of dispersion is at or near the molecular level, and by irradiation with ionizing radiation, the inorganic component and the organic component react with each other to form a film.

Examples of the inorganic component in the organic-inorganic hybrid resin include metal oxides such as silica and titania, and silica is preferable. Examples of the silica include reactive silica having a photosensitive group having photopolymerization reactivity introduced on the surface. The content of the inorganic component in the organic-inorganic hybrid resin is preferably 10% by weight or more, more preferably 20% by weight, preferably 65% by weight or less, more preferably 40% by weight or less.

As the organic component in the organic-inorganic hybrid resin, a compound having a polymerizable unsaturated group capable of polymerizing with the inorganic component (preferably reactive silica) (for example, having two or more polymerizable unsaturated groups in the molecule) And a polyunsaturated organic compound, or a monounsaturated organic compound having one polymerizable unsaturated group in the molecule).

As the thermosetting resin, silicone resin, phenol resin, urea resin, melamine resin, furan resin, unsaturated polyester resin, epoxy resin, diallyl phthalate resin, guanamine resin, ketone resin, Examples include amino alkyd resins, urethane resins, acrylic resins, polycarbonate resins and the like. These can be used alone, but it is desirable to add a curing agent in order to further improve the crosslinkability and the hardness of the crosslinked cured coating film.

As the curing agent, compounds such as polyisocyanate, amino resin, epoxy resin and carboxylic acid can be appropriately used according to the compatible resin.

As the thermoplastic resin, ABS resin, norbornene resin, silicone resin, nylon resin, polyacetal resin, polycarbonate resin, modified polyphenylene ether resin, polybutylene terephthalate, polyethylene terephthalate, sulfone resin, imide resin, fluorine resin Resin, styrene resin, acrylic resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin, polyester resin, urethane resin, nylon resin, rubber resin, polyvinyl ether, polyvinyl Examples thereof include alcohol, polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol and the like.

The binder resin 4 may be one or more resins selected from ionizing radiation curable resins, thermosetting resins, and thermoplastic resins. From the viewpoint of softening the curing shrinkage of the ionizing radiation-curable resin, the binder resin 4 is preferably a composite resin in which an ionizing radiation-curable resin and another resin are combined.

In the present embodiment, the binder resin 4 is preferably a composite resin in which an ionizing radiation curable resin and a thermoplastic resin are combined. In that case, the content of the ionizing radiation curable resin is 60% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more. The greater the amount of ionizing radiation curable resin, the better the scratch resistance. Further, by mixing the thermoplastic resin, glare can be suppressed as compared with the case where only the ionizing radiation curable resin is used.

Examples of the matting agent 3 include inorganic particles (for example, calcium carbonate, magnesium carbonate, barium sulfate, aluminum hydroxide, silica, kaolin, clay, talc, etc.) and resin particles (for example, acrylic resin particles, polystyrene resin particles, polyurethane resin). Particles, polyethylene resin particles, benzoguanamine resin particles, epoxy resin particles, silicone resin particles and the like). Among them, spherical fine particles are preferable from the viewpoint of handleability and controllability of the surface shape. In addition, the resin particles are preferable in that the difference in refractive index between the resin particles and the resin component can be easily brought close to each other, the occurrence of sparkles can be easily prevented, and the transparency can be hardly impaired.

The average particle diameter of the matting agent 3 cannot be generally determined because it varies depending on the relationship with the light emitting body 23 or the thickness of the uneven layer 2, but is 0.5 μm or more, preferably 0.8 μm or more, more preferably 1 μm or more, It is more preferably 2 μm or more and 8 μm or less, preferably 6 μm or less, and more preferably 4 μm or less. When the average particle size of the matting agent 3 is 8 μm or less, sparkle induction can be easily prevented, and when the average particle size is 0.5 μm or more, antiglare property and Newton's ring preventing property can be easily exhibited.
Further, when the particle size of the matting agent 3 becomes small, there is a tendency that glare is less likely to occur when the PPI of the light emitting body 23 becomes large. Therefore, the average particle size of the matting agent 3 is preferably small, and the average particle size is 4 μm. The following is preferable.

The matting agent 3 can be composed of a combination of a plurality of matting agents having different average particle diameters. When a matting agent having a different average particle size is included, for example, the average particle size is preferably 5 nm or more, more preferably 10 nm or more, further preferably 15 nm or more, preferably less than 500 nm, more preferably 300 nm or less, More preferably, the thickness is 200 nm or less. By using a plurality of matting agents having different average particle sizes in combination, it is easy to suppress the expression of sparkle.

The content of the matting agent 3 is 0.5 parts by weight or more, preferably 1.0 parts by weight or more, more preferably 2.0 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the binder resin. The amount is preferably 10 parts by weight or less, more preferably 5.0 parts by weight or less, still more preferably 4.0 parts by weight or less. When the content is 100 parts by weight or less with respect to 100 parts by weight, it is possible to easily prevent the sparkle from being induced, and when the content is 0.5 parts by weight or more, the antiglare property and the Newton ring prevention property are exhibited. Can be made easier. When two kinds (the first matting agent and the second matting agent) are used in combination, the weight ratio of the first matting agent and the second matting agent in all matting agents is from 100:0 to 10.00. It is preferably 20:80.

The "average particle size" and "variation coefficient of particle size distribution" of the matting agent in this example are values measured by the Coulter counter method. The Coulter counter method is a method of electrically measuring the number and size of matting agent particles dispersed in a solution, in which the particles are dispersed in an electrolytic solution and electricity is applied by using suction force. This is a method of measuring a voltage pulse proportional to the volume of a particle, in which the electrolytic solution is replaced by the volume of the particle and the resistance increases when the particle passes through the pores. Therefore, by electrically measuring the height and number of this voltage pulse, the number of particles and the volume of each particle are measured, and the particle size and particle size distribution are obtained.

Additives such as a leveling agent, an ultraviolet absorber and an antioxidant may be added to the curable composition.

When the support 5 is provided, the support 5 is, for example, a transparent film formed of a material such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyethylene, polypropylene, polystyrene, triacetyl cellulose, and acrylic. Is mentioned. Among these, a polyethylene terephthalate film which has been stretched, particularly biaxially stretched, is preferable in terms of excellent mechanical strength and dimensional stability. Further, those in which the surface of the support 5 is subjected to corona discharge treatment or an easily adhesive layer is provided to improve the adhesiveness with the optical functional layer 12 are also suitably used. The thickness of the support 5 varies depending on the relationship of the light emitter 23, but is generally 12 to 250 μm, and preferably 25 to 200 μm. In this case, the thickness of the coating film forming the uneven layer 2 is 1 to 20 μm, preferably 2 to 10 μm.

In the above-described embodiment, the method of forming the unevenness of the uneven layer 2 has been described as the coating method of the particle-containing resin, but the method is not limited to this, and for example, a sandblasting method, an embossing method, a shaping method using a mold, A roughening method such as an etching method may be used.
In the present embodiment, the concavo-convex layer 2 can be formed by applying the above-mentioned curable composition of the present embodiment onto the support 5, curing the composition by irradiating it with ionizing radiation, and then curing the composition.

The total light transmittance (JIS K7361-1:1997) of the protective film 1 is preferably 85% or more, more preferably 88% or more. By setting the total light transmittance to 85% or more, it is possible to prevent deterioration of image visibility.
The haze of the protective film 1 (JIS K7136:2000) is preferably large in consideration of the prevention of glare and glare, but when transparency is required due to the use of the protective film 1, it is 30% or less. , Preferably 20% or less. By setting the haze to 30% or less, it is possible to prevent deterioration of image visibility.

The arithmetic average roughness Ra (JIS B0601:2001) of the uneven layer 2 of the protective film 1 is 0.03 μm or more, preferably 0.05 μm or more and 0.30 μm or less, preferably 0.25 μm or less. is there. By setting Ra to 0.03 μm or more, blocking and Newton's rings can be prevented. By setting the thickness to 0.30 μm or less, glare can be prevented.

Such a protective film 1 can be used for a display device 24 having a light emitting body 23. That is, the method of using the protective film 1 of the present embodiment evaluates a protective film having a glaring index of 3.0 or less and a variation width of 1.1 or less when evaluated by an evaluation method including the above-described steps A to F. The display device 24 is provided with a light-emitting body whose surface is divided by a plurality of pixels.
That is, the protective film 1 can be used to manufacture the display device 24 including the light-emitting body 23 whose surface is divided into a plurality of pixels and the protective film 1.
According to the embodiment described above, it is possible to provide a display device in which glare is prevented in the combination of the light-emitting body 23 having any PPI and the protective film 1.
In addition, since the glare can be quantitatively evaluated by using the glare evaluation method of the above-described embodiment, it is possible to provide a display device having an effect of preventing glare based on an objective evaluation that is not affected by the eyesight and the sensitivity of the observer.

Hereinafter, the present invention will be described in more detail with reference to experimental examples in which the embodiments of the present invention are made more specific. In this experimental example, “part” and “%” are based on weight unless otherwise specified.

1. Protective film <Protective film 1 and 2>
A transparent polyester film having a thickness of 125 μm (Cosmoshine A4350: Toyobo Co., Ltd.) is coated with the coating solution for the uneven layer of the protective film 1 or 2 having the following formulation, dried, and irradiated with ultraviolet rays to form an uneven layer having a thickness of 3 μm. It formed, and the protective films 1 and 2 were obtained.

<Protective film 3>
As a protective film, KB film G50 (base material thickness 125 μm) manufactured by KIMOTO was used.

<Protective film 4>
As a protective film, KB film G90VC manufactured by KIMOTO (base material thickness 125 μm) was used.

<Protective films 5 and 6>
A 125 μm thick transparent polyester film (Cosmo Shine A4350: Toyobo Co., Ltd.) was coated with the coating solution for the uneven layer of the protective film 5 or 6 having the following formulation, dried, and irradiated with ultraviolet rays to form an uneven layer having a thickness of 3 μm. It formed, and the protective films 5 and 6 were obtained.

<Protective film 7>
It was prepared in the same manner as in the protective film 6, except that the coating solution for the uneven layer of the protective film 6 was applied to both surfaces of the transparent polyester film.

Prescription of Protective Film The following table shows the formulation of the coating liquid for the concavo-convex layer of the protective films 1, 2, 5, and 6.

The sources of the materials used for the coating liquid for the uneven layer of the protective films 1, 2, 5 and 6 are shown below.

2. Preparation of Display Device The protective films 1 to 7 were arranged on the upper surface (on the light emitting surface of the light emitting body) of the display screen of the light emitting body (light source LED) of 163 PPI (Experimental Examples 1 to 7). The protective film was arranged so that the uneven layer was on the surface. In addition, in order to obtain a reference value (Y _ref ) described later, a display device (light emitter) from which the protective films 1 to 7 were removed was prepared. A display device was similarly prepared for a light emitting body (light source LED) of 326 PPI (Experimental Examples 10 to 16). Further, for the 264 PPI light-emitting body (light source LED), display devices were similarly prepared except that protective films 4 and 7 were used as protective films (Experimental Examples 8 and 9).

3. Measurement of Glitter Index and Variation Width A display device having the above-described protective film is allowed to stand still, and a light source provided inside the display device (light-emitting body) is set to a maximum light amount and a display color is displayed in hexadecimal notation. #FFFFFF” was set and displayed in white.
Glitter evaluation device (Ikegami Tsushinki Co., Ltd., camera: RTC-21, number of pixels: QXGA (2048*1536 pixels), lens: FUJIFILM from the top of the display device so that the position is vertical to the light emitting surface of the display device. The image displayed through the protective film was color photographed using TF25-DA (25 mm). Photographic measurements were taken in a dark room.

An area of 500 pixels×500 pixels was extracted from the image obtained by photographing, and Fourier transform and inverse Fourier transform processing was performed. From the processed image, the R value, G value, B value, and standard deviation (X _R , X _G , X _B ) of the R value, G value, and B value of each pixel were calculated.
Using Equation 1 described above, the calculated R values were calculated G value, the standard deviation of the B value _{(X R,} X G, _{X B)} average value of from the (Y).

The display device from which the protective film was removed was also photographed as described above, the colorimetric region (500 pixels×500 pixels) was taken out, and the processing such as Fourier transform was performed. From the processed image, the R value, G value, B value, and standard deviation (X _R , X _G , X _B ) of the R value, G value, and B value of each pixel were calculated. The reference value (Y _ref ) which is the average value of the standard deviations of the R value, the G value, and the B value of the display device from which the protective film was removed was calculated using the above-described formula 2.

Next, the difference between Y and Y _ref was calculated as a glare index (S) by using the above-described formula 3.

Furthermore, by subtracting the minimum value of X _R , X _G , and X _B calculated for the display device having the protective film from the maximum value (see the above-mentioned formula 4), the standard deviation of the RGB values can be calculated. The difference was calculated as the variation width (D).

<Measurement conditions>
・Measurement distance: 30cm from the measurement surface to the camera lens
・Measurement angle: perpendicular to the emitting surface

4. Visual Evaluation of Glitter The liquid crystal display screen was visually observed after the entire display screen of the display device used for the measurement of the glaring index and the variation width was green-displayed. As a result, the sparkles that were slightly visible but did not interfere were rated as “◯”, and the sparkles that were clearly visible and disturbed were rated as “x”.

5. result

5. As can be seen from the results shown in Tables 3 to 5, the display devices having a glaring index of less than 3.23 and a variation width of less than 1.15 were evaluated as “◯” by visual evaluation.
Therefore, by using a protective film having a glaring index of 3.0 or less and a variation width of 1.1 or less, it is possible to provide a display device excellent in glaring prevention property even in a display device having an arbitrary PPI. I understood.
Further, as can be seen by comparing the results of Experimental Examples 1 to 4 and Experimental Examples 10 to 13, the protective films 1 to 4 had a visual evaluation of “◯” in the display device of 163 PPI, but a display of 326 PPI. It was "x" in the device. This result shows that even if the glare can be prevented by the display device of the specific PPI, the glare cannot be suppressed by the display device of the high PPI whose resolution has been improved. Therefore, it was found that it is important to evaluate the glare by combining the protective film and the luminescent material.

85... Pixel, 23... Light emitter, 1... Protective film, 24... Display device, 61... Imaging means

Claims (4)

A light emitting body whose surface is divided by a plurality of pixels, and a protective film arranged on the light emitting surface of the light emitting body,
The luminous body has a pixel density of 300 pixels/inch (PPI) or more for partitioning the plane.
The protective film contains a matting agent having a particle size of 0.8 μm or more and 4.0 μm or less and a binder resin, and has an average arithmetic average roughness Ra (JIS B0601:2001) of 0.03 μm or more and 0.30 μm or less on the surface. The uneven layer having the unevenness of
A display device characterized by selecting and using one having a glaring index of 3.0 or less and a variation width of 1.1 or less when evaluated by an evaluation method including the following steps A to F:
Step A: a step of obtaining a color image data by photographing the light emitting body through the protective film by the photographing means while the light emitting body is turned on,
Step B: a step of performing a Fourier transform on the color image data obtained in step A, removing frequency components corresponding to the array of pixels from the data after the Fourier transform, and then performing an inverse Fourier transform,
Step C: a step of calculating a standard deviation value of RBG values of each pixel of the image data after the inverse Fourier transform obtained in step B, and calculating an average value thereof by the formula 1 .
Y=(X _R +X _G +X _B )/3 (Formula 1)
In Formula 1, Y represents an average _value, X _R, X G, each _{X B} R value, standard deviation value of the G and B values.
Step D: Steps A to C are performed without disposing the protective film on the light-emitting body, and the average value of the standard deviation values of RGB values is calculated as a reference value according to Equation 2 .
Y _ref =(X _Rref +X _Gref +X _Bref )/3 (Equation 2)
In Expression 2, Y _ref represents a reference value, and X _Rref , X _Gref , and X _Bref represent standard deviation values of R value, G value, and B value, respectively.
Step E: A step of calculating the deviation amount between the average value of the standard deviation values of the RGB values calculated in step C and the reference value calculated in step D by Equation 3, and calculating the deviation amount S as a glare index.
S=(Y−Y _ref ) (Formula 3)
and,
Step F: A step of calculating the difference between the standard deviations of the RGB values calculated in Step C as the variation width D by Equation 4 .
D=X _max −X _min (Equation 4)
In the formula _{4, X max} is _{X R, X G,} the maximum value of _{X B, X min} represents the minimum value of _{X R, X G, X B} . The display device according to claim 1, wherein
The display device, wherein the concavo-convex layer of the protective film contains the matting agent in an amount of 0.5 to 15 parts by weight based on 100 parts by weight of the binder resin. A method for producing a display device including a light-emitting body whose surface is divided by a plurality of pixels, and a protective film,
Disposing the protective film on the light emitting surface of the light emitting body,
Performing an evaluation method including the following steps AF:
Step A: a step of obtaining a color image data by photographing the light emitting body through the protective film by the photographing means while the light emitting body is turned on,
Step B: a step of performing a Fourier transform on the color image data obtained in step A, removing frequency components corresponding to the array of pixels from the data after the Fourier transform, and then performing an inverse Fourier transform,
Step C: a step of calculating a standard deviation value of RBG values of each pixel of the image data after the inverse Fourier transform obtained in step B, and calculating an average value thereof by the formula 1 .
Y=(X _R +X _G +X _B )/3 (Formula 1)
In Formula 1, Y represents an average _value, X _R, X G, each _{X B} R value, standard deviation value of the G and B values.
Step D: Steps A to C are performed without disposing the protective film on the light emitting body, and the average value of the standard deviation values of RGB values is calculated as a reference value according to Equation 2 .
Y _ref =(X _Rref +X _Gref +X _Bref )/3 (Equation 2)
In Expression 2, Y _ref represents a reference value, and X _Rref , X _Gref , and X _Bref represent standard deviation values of R value, G value, and B value, respectively.
Step E: A step of calculating the deviation amount between the average value of the standard deviation values of the RBG values calculated in step C and the reference value calculated in step D by Equation 3, and calculating this deviation amount S as a glare index.
S=(Y−Y _ref ) (Equation 3) ,
And step F: a step of calculating the difference of the standard deviations of the RGB values calculated in step C as the variation width D by the equation 4 ,
D=X _max −X _min (Equation 4)
In the formula _{4, X max} is _{X R, X G,} the maximum value of _{X B, X min} represents the minimum value of _{X R, X G, X B} .
The step of disposing the protective film is characterized in that a protective film having a glare index of 3.0 or less and a variation width of 1.1 or less when evaluated in the step of the evaluation method is used as the protective film. , A method for manufacturing a display device. Evaluated by an evaluation method including the following steps A to F, a protective film having a glaring index of 3.0 or less and a variation width of 1.1 or less, and a light-emitting body whose in-plane is divided into a plurality of pixels are provided. How to use the protective film characterized by being used for the display device:
Step A: a step of obtaining a color image data by photographing the light emitting body through the protective film by the photographing means while the light emitting body is turned on,
Step B: a step of performing a Fourier transform on the color image data obtained in step A, removing frequency components corresponding to the array of pixels from the data after the Fourier transform, and then performing an inverse Fourier transform,
Step C: a step of calculating a standard deviation value of RBG values of each pixel of the image data after the inverse Fourier transform obtained in step B, and calculating an average value thereof by the formula 1 .
Y=(X _R +X _G +X _B )/3 (Formula 1)
In Formula 1, Y represents an average _value, X _R, X G, each _{X B} R value, standard deviation value of the G and B values.
Step D: Steps A to C are performed without disposing the protective film on the light emitting body, and the average value of the standard deviation values of RGB values is calculated as a reference value according to Equation 2 .
Y _ref =(X _Rref +X _Gref +X _Bref )/3 (Equation 2)
In Expression 2, Y _ref represents a reference value, and X _Rref , X _Gref , and X _Bref represent standard deviation values of R value, G value, and B value, respectively.
Step E: A step of calculating the deviation amount between the average value of the standard deviation values of the RBG values calculated in step C and the reference value calculated in step D by Equation 3, and calculating this deviation amount S as a glare index.
S=(Y−Y _ref ) (Equation 3) ,
And step F: a step of calculating the difference of the standard deviations of the RGB values calculated in step C as the variation width D by the equation 4 ,
D=X _max −X _min (Equation 4)
In the formula _{4, X max} is _{X R, X G,} the maximum value of _{X B, X min} represents the minimum value of _{X R, X G, X B} .

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