JP2009237464A - Image contrast enhancing filter, method of manufacturing the same, and image display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image contrast enhancing filter which is capable of enhancing contrast of a display image and prevents a light-transmissive area being a transmission region of the image from being stained or flawed, and the method of manufacturing the same. <P>SOLUTION: A filter 100 has, on one surface S1 of a transparent base material 4, linear dark color parts 10 formed in parallel along the in-plane direction of the transparent base material 4 and having trapezoidal or approximately trapezoidal cross-sections in a direction perpendicular to their extension direction, and light-transmissive areas 20 between the adjacent dark color parts 10, 10. In the filter 100, each dark color part 10 is formed by filling dark color particles 1 and a transparent resin 2 in a groove-like recess 3 having a trapezoidal or approximately trapezoidal cross-section, and each light-transmissive area 20 is formed by coating the surface (flat portion 8) of the transparent base material 4 with a transparent protective layer 2L made of the transparent resin 2. The filter is configured so that relation of t<dmin<dmax<W and t<dmin<dmax<H are established, wherein: dmin and dmax are minimum particle size and maximum particle size of dark color particles 1 respectively; t is the thickness of the transparent protective layer 2L; and W and H are the maximum width and the depth of the groove-like recess 3, respectively. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image contrast enhancement filter that is preferably provided on the front surface of an image display device such as a PDP, LCD, or CRT, a manufacturing method thereof, and an image display device.

  In image display devices such as a plasma display device (PDP), a liquid crystal display device (LCD), a cathode ray tube display device (CRT), and an electroluminescence display device (EL), studies have been conducted to improve the image quality. It was.

  In particular, as an example of improving the image quality by providing a functional member on the front side of the image display device, for example, Patent Document 1 discloses a screen having a mesh film in which strands are knitted and crossed in order to prevent flickering of an image. It has been proposed to be placed in front of. This reticulated film is thought to be effective in preventing flickering of the image, but when external light such as sunlight or electric light (also referred to as extraneous light) is incident on the screen, the image contrast is lowered. There is. For such a problem, for example, it is conceivable to use a black fiber having light absorption performance as the strand. However, external light is incident from an oblique direction of the screen, while image light is emitted in a direction orthogonal to the screen, so that only the external light is absorbed with high efficiency without improving the image contrast. In order to achieve this, external light incident from an oblique direction of the screen is increased by increasing the length of the black fiber in the depth direction (that is, the direction connecting the image display device and the viewer, in other words, the orthogonal direction of the screen). Must be received over a large area. However, in order to increase the length of the fiber in the depth direction, it is necessary to increase the fiber diameter, and as a result, the width (direction parallel to the screen) is inevitably increased and the image light transmitted to the viewer side is increased. The problem of being disturbed by black fibers arises.

  For example, Patent Document 2 proposes a micromesh type antireflection filter for preventing reflection on the screen of a color cathode ray tube display device. This antireflection filter is made of a micromesh in which nylon single fibers are plain-woven into a mesh shape, and the micromesh is in a constant pitch range with respect to the horizontal pitch and vertical pitch of the dot pitch of the fluorescent film, and The micromesh weft is in a certain angle range with respect to the horizontal scanning line. Such an antireflection filter is considered to be effective in preventing the occurrence of moire, but the problem that the image contrast is lowered when external light such as sunlight or electric light enters the screen cannot be solved.

In order to solve the problem of improving the image contrast, for example, in Patent Document 3, as a contrast enhancement layer constituting a front filter for PDP bonded to a screen, the image is linearly connected in a predetermined direction along the surface direction of the layer, The cross section perpendicular to the extending direction has a trapezoidal shape with the bottom of the wide side facing the observer side, and is connected in a straight line in a direction parallel to the lens part that transmits light and the lens part. The cross-section perpendicular to the extending direction has a wedge-shaped shape with the lower bottom facing the PDP side, and a plurality of light absorbing portions that absorb light are alternately meshed and arranged. Proposes what will be. This front filter is intended to improve image contrast in a mode that also has an electromagnetic wave shielding function.
Japanese Patent Publication No.34-8069 JP-A-62-136741 JP 2007-272161 A

  However, the front filter proposed in Patent Document 3 has insufficient points for further practical use and higher quality, and the solution is required.

  In other words, the front filter proposed in Patent Document 3 has a light-absorbing portion formed by filling a wedge-shaped groove with a paint made of dark resin, and the light-absorbing portion has a wedge-shaped groove portion in parallel. It is formed by applying a paint made of dark resin on the provided surface and then scraping it with a doctor blade or the like. However, when scraping with a doctor blade or the like, dark resin remains in the translucent region (appears as a convex portion with respect to the groove-shaped recess) which is the surface of the transparent base other than the groove, and the translucent property There is a drawback that the light transmittance of the region is lowered and the display image becomes dark. The reason why the dark resin remains in the translucent area is that the flatness of the translucent area is incomplete unlike flat rigid bodies such as glass plates and metal plates, and it is deformed by pressing a doctor blade or the like. This is due to the fact that it is impossible to scrape completely due to, for example, bending and the dark resin paint being liquid and oozing into even a small gap.

  Although it is possible to wipe or polish the dark paint remaining in the translucent area with a cloth soaked with an organic solvent, the number of steps is increased and the translucent area is added with the organic solvent. May become cloudy due to swelling / elution, or scratches may accompany the polishing, and the display image may become cloudy due to these factors.

  Further, the front filter is basically in an exposed state although dark resin remains in the translucent region. Eventually, the translucent area is covered with some kind of member (for example, a front plate), but the exposed translucent area is exposed during various processing steps, transport steps, or storage steps. As a result, there is a problem that the quality of the display image is deteriorated.

  The present invention has been made in order to solve the above-described problems. The object of the present invention is to improve the contrast of a display image and to contaminate or damage a translucent region that is a transmission part of the image. An object of the present invention is to provide an image contrast enhancement filter and a method for manufacturing the same, which are not attached.

  Another object of the present invention is to provide an image display apparatus provided with such an image contrast enhancement filter on a display surface.

  The image contrast enhancement filter of the present invention for solving the above-mentioned problem is a linear and parallel extending direction parallel to the one surface of the transparent substrate along the in-plane direction of the transparent substrate. A cross-sectional shape orthogonal to the trapezoidal or substantially trapezoidal dark color portion and a light-transmitting region between the adjacent dark color portions, wherein the dark color portion has a trapezoidal or substantially trapezoidal cross-sectional shape. The groove-shaped recess is filled with dark particles and a transparent resin, and the translucent region is covered with a transparent protective layer made of a transparent resin, and the dark particles have a minimum particle diameter dmin and Between the maximum particle diameter dmax, the thickness t of the transparent protective layer, and the maximum width W and depth H of the groove-shaped recess, t <dmin <dmax <W and t <dmin <dmax <H The relationship is established.

  According to the present invention, the groove portion having a trapezoidal or substantially trapezoidal cross-sectional shape is filled with dark particles and a transparent resin, and the surface of the transparent substrate is covered with the transparent protective layer made of the transparent resin. The transparent regions are arranged in parallel alternately in the in-plane direction of the transparent substrate, and the minimum particle size and the maximum particle size of the dark particles, the thickness of the transparent protective layer, and the grooves Since the maximum width and depth of the concave portion are configured as described above, dark particles are not present in the light-transmitting region, and the light transmittance of light passing through the light-transmitting region is not deteriorated. As a result, the display image becomes dark and the visibility of the display image is not impaired, and the dark color portion effectively absorbs external light, so that the contrast of the image can be improved.

  Furthermore, according to the present invention, since the transparent region of the transparent base material is covered with the transparent protective layer made of a transparent resin, the transparent region of the image can be transmitted in various processing steps, transport steps, and storage steps. Certain translucent areas are not contaminated or scratched. As a result, it is possible to display a high-quality image without degrading the image quality of the display image.

  In a preferred embodiment of the image contrast improving filter of the present invention, a transparent support is further laminated on the surface of the transparent base material on the side where the transparent protective layer is not formed.

  In a preferred aspect of the image contrast enhancement filter of the present invention, one or more optical filters are further provided on one surface and / or the other surface of the image contrast enhancement filter.

  The image display device of the present invention for solving the above-mentioned problems is the position where the image contrast improving filter of the present invention is opposed to the front surface of the image display unit, and the dark color portion having the larger width of the trapezoid or substantially trapezoid. It is characterized by being arranged so that the bottom side faces the image display unit side.

  According to this invention, since the filter according to the present invention described above is provided on the image display unit side, the quality and contrast of the display image can be improved. In particular, since the dark color portion composed of a trapezoidal shape or a substantially trapezoidal shape is arranged so that the bottom of the larger width portion faces the image display portion side, external light can be effectively absorbed by the dark color portion.

In order to solve the above-mentioned problems, the method for producing an image contrast enhancement filter of the present invention is a method in which a linear shape arranged in parallel along the in-plane direction of one surface and a cross-sectional shape perpendicular to the extending direction is a trapezoid. Alternatively, a step of preparing a transparent substrate formed with a substantially trapezoidal groove-shaped recess, and a step of applying a liquid resin composition having dark particles and a transparent resin to the surface on which the groove-shaped recess is formed. And scraping off the applied liquid resin composition, filling the groove-shaped recesses with the dark particles and the transparent resin, and allowing the dark particles to exist in flat portions other than the groove-shaped recesses. A step of leaving the transparent resin at a predetermined thickness, and solidifying the transparent resin so that the groove-shaped concave portion is a dark color portion, and the flat portion is covered with a transparent protective layer having a predetermined thickness. And at least a process comprising:
Between the minimum particle size dmin and the maximum particle size dmax of the dark color particles, the thickness t ′ of the transparent resin remaining in the flat portion, and the maximum width W and depth H of the groove-shaped recess, t ′ < The relationship is dmin <dmax <W and t ′ <dmin <dmax <H.

  According to this invention, since the minimum particle size and the maximum particle size of the dark particles, the thickness of the transparent resin remaining in the flat portion, and the maximum width and depth of the groove-shaped recess are configured in the above relationship, the liquid resin composition is In the predetermined thickness t ′ remaining on the flat portion after scraping, there are no dark colored particles and only transparent resin is present. Then, by solidifying the transparent resin thereafter, it is possible to manufacture a filter in which the groove-like concave portion is a dark color portion and the flat portion is a translucent region covered with a transparent protective layer having a predetermined thickness. Since the filter manufactured in this way has no dark particles in the light-transmitting region, the light transmittance of the light passing through the light-transmitting region is not deteriorated, and the display image becomes dark and the visibility of the display image is reduced. Will not be damaged. Moreover, since the dark color portion effectively absorbs external light, the contrast of the image can be improved. Furthermore, since the translucent area is covered with a transparent protective layer, the translucent area, which is the transmission area of the image, is contaminated or scratched even after various processing steps, conveyance processes, storage processes, etc. do not do. As a result, it is possible to display a high-quality image without degrading the image quality of the display image.

  In a preferred aspect of the method for producing an image contrast improving filter of the present invention, the predetermined thickness t ′ of the transparent resin is formed to be equal to or greater than the predetermined thickness t of the transparent protective layer.

  According to the image contrast improving filter of the present invention, dark particles are not present in the translucent area, and the light transmissivity of light passing through the translucent area does not deteriorate, so the display image becomes dark and the display image Visibility is not impaired. Moreover, since the dark color portion effectively absorbs external light, the contrast of the image can be improved. Furthermore, since the transparent region of the transparent base material is covered with a transparent protective layer made of a transparent resin, the transparent region that is the transmission region of the image is also present during various processing steps, transport steps, and storage steps. It will not be contaminated or scratched. As a result, it is possible to display a high-quality image without degrading the image quality of the display image.

  According to the method for producing an image contrast improving filter of the present invention, dark particles are not present in the predetermined thickness t ′ remaining on the flat portion after the liquid resin composition is scraped, and only the transparent resin is present. Therefore, by subsequently solidifying the transparent resin, it is possible to manufacture a filter in which the groove-shaped concave portion is a dark color portion and the flat portion is a translucent region covered with a transparent protective layer having a predetermined thickness. As a result, the filter manufactured in this way exhibits the above-mentioned preferable effects, can improve the contrast of the image, and further displays a high-quality image without degrading the image quality of the display image. be able to.

  According to the image display device of the present invention, the quality and contrast of the display image can be improved.

  Hereinafter, an image contrast improving filter, a manufacturing method thereof, and an image display device of the present invention will be described with reference to the drawings. The technical scope of the present invention is not limited to the following embodiments.

[Image contrast enhancement filter]
FIG. 1 is a schematic cross-sectional view (A) showing an example of an image contrast enhancement filter (hereinafter simply referred to as “filter”) of the present invention, and a plan view (B) of the image contrast enhancement filter viewed from the dark color side. FIG. 2 is a perspective view of the filter of the present invention provided with a transparent support. FIG. 3 is a schematic cross-sectional view showing another example of the filter of the present invention.

  As shown in FIGS. 1 and 2, the filter 100 (100 </ b> A, 110 </ b> B) of the present invention is juxtaposed in parallel along the in-plane direction of the transparent substrate 4 on one surface of the transparent substrate 4. A dark color portion 10 having a straight and trapezoidal or substantially trapezoidal cross-sectional shape perpendicular to the extending direction thereof, and a translucent region 20 between adjacent dark color portions 10 and 10 are provided. The dark color portion 10 is configured by filling the groove-shaped concave portion 3 having a trapezoidal or substantially trapezoidal cross-sectional shape with the dark particles 1 and the transparent resin 2. Moreover, the translucent area | region 20 is the transparent protective layer 2L which the surface S1 of the flat part 8 (the part in which the groove-shaped recessed part 3 is not formed, see FIG.4 (C)) of the transparent base material 4 consists of the transparent resin 2. Consists of covered. In the present invention, between the minimum particle diameter dmin and the maximum particle diameter dmax of the dark color particle 1, the thickness t of the transparent protective layer 2L, and the maximum width W and depth H of the groove-shaped recess 3, t < The relationship is dmin <dmax <W and t <dmin <dmax <H.

  In the filter 10 of the present invention having such a configuration, the dark particles 1 are not present in the light-transmitting region 20 and the light transmittance of light passing through the light-transmitting region does not deteriorate, so the display image becomes dark. The visibility of the display image is not impaired. Moreover, in the dark color part 10, since the dark color particle | grains 1 absorb external light effectively, the contrast (defined by the ratio of the brightness | luminance of a white part and a black part of an image, a difference, etc.) can be improved. Further, since the translucent region 20 is covered with the transparent protective layer 2L, the translucent region 20 that is the transmission region of the image is contaminated or scratched during various processing steps, transport steps, and storage steps. It is possible to display a high quality image without being attached and without degrading the image quality of the display image.

  Hereinafter, each component of the filter of the present invention will be described in detail.

(Transparent substrate)
As the transparent base material 4, various kinds of resin materials such as ionizing radiation curable resins, thermosetting resins and thermoplastic resins, or inorganic transparent materials such as glass can be used. Usually, a resin material is preferably used in that it is easy to form the groove-like recess 3, can be light and thin, and is excellent in flexibility. About ionizing radiation curable resin and thermosetting resin, it can select from the thing similar to what was illustrated by the description location of the transparent resin mentioned later, and can be used. Examples of the thermoplastic resin include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin resins such as polyethylene, polypropylene, cyclic polyolefin, and polymethylpentene, polyvinyl chloride, and polyvinylidene chloride. Styrenic resins such as halogen resins, polystyrene, acrylonitrile-styrene copolymers, cellulose resins such as triacetyl cellulose, diacetyl cellulose, and acetate butyrate cellulose, thermoplastic polyurethane resins, polycarbonate resins, polyamide resins, and the like can be used.

  Since the groove-like recess 3 is formed in the transparent base material 4, the thickness thereof needs to be thicker than the depth H of the groove-like recess 3, and is usually in the range of about 20 μm to 5000 μm. That is, the transparent substrate 4 can take various forms of a so-called film, sheet, or plate in terms of thickness.

(Dark part)
As shown in FIGS. 1 and 2, the dark color portion 10 is formed on one surface of the transparent base material 4, and is a straight line arranged in parallel along the in-plane direction of the transparent base material 4. And the cross-sectional shape orthogonal to the extension direction consists of a trapezoid or a substantially trapezoid form. And this dark color part 10 is filled with the dark particle 1 and the transparent resin 2 in the groove-shaped recessed part 3 whose cross-sectional shape is trapezoid or substantially trapezoid.

  First, the shape of the groove-shaped recess 3 will be described. As shown in FIGS. 1 and 2, the groove-shaped recess 3 has a trapezoidal or substantially trapezoidal cross-sectional shape. Here, the cross-sectional shape refers to a cross-sectional shape orthogonal to the extending direction of the groove-shaped recess 3 extending linearly. In addition, as shown in FIG. 4A, the trapezoidal groove-like recess has a wide width W on one side S1 side (lower base) of the transparent substrate 4 and a side on the other side S2 ( The width of the upper bottom) is configured in a narrow manner. In addition, the substantially trapezoidal groove-shaped recess includes a shape having a small difference in width between both sides (upper base and lower base), that is, a shape close to a rectangle or a square. Also included is a shape approximating a triangle cut parallel to the side (bottom base). The groove-like recess 3 is not limited to such a trapezoid or a substantially trapezoid, but may be a square such as a square or a rectangle, or a polygon such as a triangle or a pentagon, but is preferably a trapezoid or a substantially trapezoid as described above. is there.

  In particular, in terms of compatibility with the effect of improving image contrast in the presence of external light, the brightness (brightness) of the image, and the high viewing angle of the image, the groove-shaped recess 3 has a trapezoidal cross-sectional shape and opposes it. There is a significant difference between the widths of both sides (upper and lower bases), a wide bottom is provided on the image display device side (ie, surface S1 side), a narrow bottom is provided on the viewer side (ie, surface S2 side), and the groove It is preferable that the width (maximum width) W of the side (lower base) having the larger depth H is larger.

  Thus, unlike the conventional black fiber, the groove-like recess 3 can set the maximum width W and the depth H independently. The side portion (the depth H direction) of the dark color portion 10 that absorbs most of the external light incident from the oblique direction by increasing the repetition period between the concave portions, increasing the aperture ratio, and increasing the depth H. It is possible to increase the surface area of the side surface. As a result, it is possible to achieve both a high light transmittance of image light and a high light absorption rate of external light, which were impossible with a black fiber mesh. Here, the aperture ratio refers to the ratio of the area of the opening (the portion where the dark color portion 10 is not formed, that is, the translucent region 20) to the total area viewed from the normal direction of the filter 100.

  The angle θ between the inclined surface 5 formed by the interface between the groove-shaped recess 3 and the transparent substrate 4 and the normal line of the light exit surface (line P parallel to the perpendicular incident light with respect to the filter 100) is formed at a predetermined angle. For example, θ is preferably in the range of 3 ° to 15 °. When θ is 3 ° or more, the display light from the image display device sufficiently reaches the observer side, and an effect of improving luminance can be obtained. In addition, the external light incident on the screen in an oblique direction can be absorbed by the dark color portion 10 having a sufficient cross-sectional area, so that reflection of external light can be suppressed and image contrast can be improved. On the other hand, when θ is 15 ° or less, the area of the translucent region (dark color portion non-forming region) through which image light passes can be kept high while maintaining the cross-sectional area of the side surface of the dark color portion 10 that absorbs external light. Therefore, the intensity (luminance) of the image light can be kept high.

  The length of the larger base of the groove-shaped recess 3 (that is, the maximum width W) is preferably about 10 μm to 100 μm, and the length of the smaller base is preferably about 5 μm to 50 μm. The length H is preferably about 10 μm to 200 μm, the period (pitch) of the groove-shaped recess 3 is preferably about 10 μm to 900 μm, and the aperture ratio is preferably about 50% to 90%.

  Next, a material constituting the dark color portion 10, that is, a material filled in the groove-like recess 3 will be described. The dark color portion 10 preferably absorbs most of the visible light wavelength region and absorbs incident visible light (external light) at a high rate. As a result, the external light reflected by the dark color portion 10 is inconspicuous. Even if the reflected light is mixed into the image light, the decrease in the image contrast becomes inconspicuous. Therefore, it is desirable to set the dark color portion 10 to a color that exhibits such an effect. The black color of the dark color portion 10 is ideally ideal, but it is not necessary to be completely black for practical use, and may be a chromatic color as long as it exhibits the above action. Specifically, it may be an achromatic color such as black or dark gray, or a low-lightness chromatic color such as brown, rosy, dark blue, dark green, or dark purple.

  As the dark color particles 1 constituting the dark color portion 10, particles of each color having a predetermined particle diameter can be used. For example, as black particles, black pigments such as carbon black (black) and black iron oxide, resin particles obtained by staining transparent particles such as acrylic with black pigments such as carbon black, and the like are used.

  The dark particles 1 may be pigment particles that are achromatic by mixing various pigments of blue, purple, yellow, and red other than black particles, or resin particles that are dyed with these pigments. Also good. Copper phthalocyanine blue, indanthrene blue, cobalt blue, ultramarine blue, etc. are used as blue pigments, dioxazine violet, etc. are used as purple pigments, and disazo yellow, isoindolinone yellow, yellow lead are used as yellow pigments. As the red pigment, chromophthal red typel, quinacridone red, petal or the like is used, and as the green pigment, copper phthalocyanine green, patina or the like is used. Further, it may be a dark particle 1 having a chromatic color with low brightness, and as an example, one or more of the above-mentioned blue, purple, yellow, red, or green pigments are appropriately mixed and dispersed. If necessary, it may be a colored pigment further mixed with a black pigment, or resin particles obtained by coloring transparent particles such as acrylic with these pigments. Among these dark colored particles 1, black particles are preferred because they have the highest light absorption and do not affect the hue of the filter of the present invention.

  As the particle diameter of the dark particles 1, it is necessary that the minimum particle diameter dmin and the maximum particle diameter dmax satisfy the relationship described later. That is, at least the maximum particle diameter dmax of the dark color particles 1 needs to be smaller than the maximum width W of the groove-shaped recess 3 and smaller than the depth H thereof. On the other hand, the minimum particle diameter dmin of the dark color particles 1 needs to be larger than the thickness of the transparent protective layer 2L. Accordingly, the particle size of the dark particles 1 is arbitrarily selected and used as long as it satisfies such conditions, but is usually arbitrarily selected from the range of 0.1 μm to 100 μm. The minimum particle size dmin and the maximum particle size dmax of the dark color particles 1 can be measured by observing the dark color particles 1 to be used with an electron microscope.

  Various materials such as ionizing radiation curable resin, thermosetting resin, and thermoplastic resin can be used as the transparent resin 2 constituting the dark color portion 10 together with the dark color particles 1. The ionizing radiation curable resin means a resin that is cured by crosslinking or polymerization reaction by irradiation with electromagnetic waves or charged particle beams such as ultraviolet rays or electron beams. Examples of such an ionizing radiation curable resin include an ionizing radiation polymerizable prepolymer and / or an ionizing radiation polymerizable monomer.

  Examples of ionizing radiation polymerizable prepolymers (including oligomers) include polyester (meth) acrylates, epoxy (meth) acrylates, urethane (meth) acrylates, polyol (meth) acrylates, silicon (meth) acrylates, Cationically polymerizable functional groups in molecules such as unsaturated polyester-based polymerizable oligomers having radically polymerizable functional groups in the molecule, or novolak-type epoxy resin prepolymers, aromatic vinyl ether-based resin prepolymers, etc. Examples thereof include a polymerizable oligomer having a group. These ionizing radiation polymerizable prepolymers may be used singly or in combination of two or more. Here, “(meth) acrylate” means “acrylate or methacrylate”.

  The ionizing radiation polymerizable monomer (monomer) is preferably a polyfunctional (meth) acrylate which is a polymerizable monomer having a radical polymerizable functional group in the molecule, specifically ethylene glycol di (meth). Acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, etc. It is done. Examples of the monomer having a cationic polymerizable functional group include alicyclic epoxides such as 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate, glycidyl ethers such as bisphenol A diglycidyl ether, 4 -Vinyl ethers such as hydroxybutyl vinyl ether and oxetanes such as 3-ethyl-3-hydroxymethyloxetane. These ionizing radiation polymerizable monomers may be used alone or in combination of two or more, or may be used in combination with the ionizing radiation polymerizable prepolymer.

  When an ultraviolet curable resin is used as the ionizing radiation curable resin, it is desirable to add about 0.1 to 5 parts by mass of the photopolymerization initiator with respect to 100 parts by mass of the ionizing radiation curable resin. The initiator for photopolymerization can be appropriately selected from those conventionally used and is not particularly limited.

  For polymerizable monomers and polymerizable oligomers having radically polymerizable functional groups in the molecule, benzoin, benzoin methyl ether, acetophenone, dimethylaminoacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one 1-hydroxycyclohexyl phenyl ketone, benzophenone, p-phenylbenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal and the like. In addition, for polymerizable monomers and polymerizable oligomers having a cationic polymerizable functional group in the molecule, aromatic sulfonium salts, aromatic diazonium salts, aromatic iodonium salts, metallocene compounds, benzoin sulfonate esters, etc. It is done. Moreover, as a photosensitizer, p-dimethylbenzoic acid ester, tertiary amines, a thiol type sensitizer, etc. can be used, for example.

  Thermosetting resins include phenolic resin, phenol-formalin resin, urea resin, urea-formalin resin, melamine resin, polyester-melamine resin, melamine-formalin resin, alkyd resin, epoxy resin, epoxy-melamine resin, unsaturated polyester. Examples thereof include resins, polyimide resins, acrylic resins, polysiloxane resins, polyurethane resins, general-purpose two-component curable acrylic resins (acrylic polyol cured products), and the like.

(Translucent area)
The translucent region 20 is as shown in FIGS. The surface S1 of the transparent base material 4 is located between the adjacent dark portions 10 and 10 and covered with the transparent protective layer 2L. In this transparent protective layer 2L, only the transparent resin 2 that fills the groove-shaped recess 3 together with the dark color particles 1 is a groove-shaped recess non-formation portion (also referred to as a convex portion or a translucent opening) of the transparent base material 4. That is, the light-transmitting region 20 is covered. The thickness t of the transparent protective layer 2L is defined by the relationship between the minimum particle size and the maximum particle size of the dark color particles 1 to be used, and is in a range of 0.1 μm to 30 μm as long as the relationship described later is satisfied. It is preferable. When the thickness t of the transparent protective layer 2L is less than 0.1 μm, the transparent protective layer 2L formed on the convex portion which is the flat portion 8 other than the groove-shaped concave portion 3 of the transparent base material 4 is polished or wiped in a normal manufacturing method. It is difficult to realize without the use, and it is insufficient as a protective layer mainly from contamination and scratches on the surface of the translucent region 20. On the other hand, when the thickness t of the transparent protective layer 2L exceeds 30 μm, it is not preferable because the surface protection function becomes excessive quality and unnecessary price increases. In protecting the transparent protective layer 2L from contamination and scratches, an ionizing radiation curable resin or a thermosetting resin having high hardness and excellent scratch resistance is preferable.

(Relationship between dark color and translucent area)
The feature of the present invention is that the components of the dark color portion 10 and the translucent region 20 are configured as follows. That is, the minimum particle size dmin and the maximum particle size dmax of the dark particle 1 are transparent. A relationship of t <dmin <dmax <W and t <dmin <dmax <H is established between the thickness t of the protective layer 2L and the maximum width W and depth H of the groove-shaped recess 3. It is characterized by being composed.

  When the filter 100 of the present invention satisfies such a relationship, the dark color particles 1 exist only in the groove-shaped recess 3 and do not exist in the translucent region 20. On the other hand, the transparent resin 2 exists over both the dark color portion 10 and the translucent region 20, and the translucent region 20 is covered with a transparent protective layer 2 </ b> L made of only the transparent resin 2. Here, the fact that the dark particles 1 are present only in the groove-shaped recesses 3 includes, strictly speaking, those in which a part of the dark color particles 1 are hung in the groove-shaped recesses 3 as shown in FIG. . In particular, in the relationship between the minimum particle size dmin and the thickness t, it is more preferable that dmin / t = 1.5 to 10, and in the relationship between the maximum particle size dmax and W to H, W / dmax = More preferably, it is 2-50, and it is more preferable that H / dmax = 2-100. Note that it is more preferable that H> W from the viewpoint of further improving contrast by absorbing external light.

(Transparent support)
As shown in FIG. 2, the transparent support 6 can be provided on the surface S <b> 2 on the transparent protective layer non-forming side of the transparent substrate 3 as necessary. In the present application, a filter including the transparent support 6 shown in FIG. 2 is denoted by reference numeral 100B, and a filter not including the transparent support 6 shown in FIG. 1 is denoted by reference numeral 100A. The transparent support 6 supports the transparent substrate 4 and reinforces the mechanical strength of the transparent substrate 4, or forms a layer of the transparent substrate 4 and forms the groove-shaped recess 3 on the transparent substrate 4. It is preferably provided for the purpose of providing processing suitability in processing steps such as filling the groove-shaped recess 3 with the composition for forming a dark color portion, forming the transparent protective layer 2L, and laminating the filter 100 on other members. is there. The material of the transparent support 6 can be appropriately selected and applied from the materials described for the transparent substrate 4 described above in light of the purpose of providing the transparent support 6. Further, the thickness of the transparent support 6 may be appropriately selected in view of the purpose of providing the transparent support 6.

  As can be seen from the perspective view of FIG. 2, a large number of the dark colored portions 10 are arranged in parallel along the in-plane direction of the transparent substrate 4, are formed in a straight line shape, and extend in the direction ( The cross-sectional shape orthogonal to the y direction in FIG. 2 has a trapezoidal or substantially trapezoidal shape.

(Combination with other members)
FIG. 3 is a schematic cross-sectional view showing an example in which one or more optical filters are further provided on one surface and / or the other surface of the filter. FIG. 3A shows an example in which an optical filter 40A is provided on the surface on which the dark color portion 10 and the translucent region 20 are formed. FIG. 3B shows the dark color portion 10 and the translucent region 20. FIG. 3C shows an example in which optical filters 40A and 40B are provided on both sides of the optical filter 40B.

  The filter 100 of the present invention can be arbitrarily provided with optical filters (40A, 40B). As an optical filter, for example, one or more optical functions selected from a near-infrared absorption function, a neon light absorption function, a toning function, an ultraviolet absorption function, an antireflection function, an antiglare function, etc. The layer which has, a film thru | or sheet | seat, or a board | plate material can be mentioned. Such an optical filter may be provided as a single layer or a plurality of optical filters may be stacked. Moreover, you may make such a filter function bear the transparent support body 6 mentioned above. As these functional filters, those described in paragraphs 0064 and after of JP-A-2007-272161 can be applied. In the present invention, a layer having other functions such as an electromagnetic wave shielding function, a stain resistance function, an anti-scratch function, and an antistatic function may be further laminated on the optical filter having such an optical function.

[Filter manufacturing method]
Next, production examples of the filter of the present invention will be described. FIG. 4 is a process flow diagram showing an example of the filter manufacturing method of the present invention.

  First, as shown in FIG. 4 (A), a linear groove arranged in parallel along the in-plane direction of one surface S1 and a cross-sectional shape orthogonal to the extending direction is a trapezoidal or substantially trapezoidal groove shape. A transparent substrate 4 in which the recess 3 is formed is prepared. The groove-shaped recess 3 can be processed by various methods. For example, a hot pressing method in which a heated shaping mold is pressed against a thermoplastic resin, a casting method in which a thermoplastic resin composition is injected onto the shaping mold and solidified, an injection molding method, an ultraviolet curable resin composition It can be formed by arbitrarily selecting a method such as a UV casting method in which it is injected into a mold and UV-cured. Among these methods, the UV casting method excellent in mass productivity is more preferable. The UV casting method can be produced by using a roll-shaped mold and continuously embossing the groove-shaped recess 3 while supplying a continuous sheet. An example of a roll-shaped mold is one in which a copper layer is laminated on the surface of a hollow iron cylinder and the inverted shape of the groove-shaped recess 3 to be formed in the copper layer is formed.

  Next, as shown in FIG. 4B, a liquid resin composition 7 having dark particles 1 and a transparent resin 2 is applied to the surface S1 on the side where the groove-shaped recess 3 is formed. Application can be performed using the nozzle 71 or the like. The liquid resin composition is prepared by arbitrarily selecting the dark color particles 1 and the transparent resin 2 described above, and blending a solvent as necessary to obtain a predetermined viscosity. In addition, in order to improve the ease of manufacture, you may add additives, such as a defoaming agent and a leveling agent, to a liquid resin composition.

  Next, as shown in FIG. 4 (C), the applied liquid resin composition 7 is scraped, and the groove-like recesses 3 are filled with the dark particles 1 and the transparent resin 2, and other than the groove-like recesses. Only the transparent resin 2 is left with a predetermined thickness t ′ without the dark particles 1 being present on the flat portion 8. The scraping can be performed, for example, by a wiping method using a doctor blade 72 or the like. At this time, a predetermined gap is formed between the doctor blade 72 or the like and the flat portion 8. The predetermined gap at this time is such that the thickness t ′ of the transparent resin 2 remaining on the flat portion 8 after scraping is equal to or greater than the thickness t of the transparent protective layer 2L formed by the next solidification step. It forms so that the relationship mentioned later may be satisfy | filled.

  Finally, as shown in FIG. 4 (D), the transparent resin 2 is solidified, the groove-like recesses 3 are used as dark portions 10, and the flat portions 8 are covered with a transparent protective layer 2L having a predetermined thickness t. The sex region 20 is assumed. Thus, the filter 100 of the present invention can be manufactured.

  The filter 100 (100A) according to the present invention is manufactured through these steps. In the present invention, the manufacturing conditions are set so that the obtained filter 100 has the following relationship. That is, between the minimum particle diameter dmin and the maximum particle diameter dmax of the dark particles 1, the thickness t ′ of the transparent resin 2 remaining in the flat portion 8, and the maximum width W and depth H of the groove-shaped recess 3 The relationship of t ′ <dmin <dmax <W and t ′ <dmin <dmax <H is established. Therefore, the specifications for the maximum width W and depth H of the groove-shaped recess 3 formed in the transparent substrate 4 to be prepared should satisfy the above relationship, and also satisfy the above relationship when preparing the liquid resin composition. The dark particles 1 are selected, and the gap between the doctor blade and the flat portion 8 is prepared so that the thickness t ′ is obtained even when the liquid resin composition is scraped off by the doctor blade or the like.

  As described above, according to the method for manufacturing a filter according to the present invention, the dark particles 1 are not present in the predetermined thickness t ′ remaining on the flat portion 8 after the liquid resin composition 7 is scraped off, and the transparent resin There are only two. After that, the transparent resin 2 is solidified to manufacture a filter in which the groove-like recess 3 is a dark color portion 10 and the flat portion 8 is a translucent region 10 covered with a transparent protective layer 2L having a predetermined thickness t. it can. In the filter 100 manufactured in this way, since the dark particles 1 do not exist in the translucent region 20, the light transmissivity of light passing through the translucent region 10 does not decrease, and the display image becomes dark and displayed. The visibility of the image is not impaired. In addition, since the dark color portion 10 effectively absorbs external light, the contrast of the image can be improved. Furthermore, since the transparent region 20 is covered with the transparent protective layer 2L, the transparent region 20 that is the transmission region of the image is contaminated or scratched even after various processing steps, conveyance steps, storage steps, and the like. Does not stick. As a result, it is possible to display a high-quality image without degrading the image quality of the display image.

[Image display device]
FIG. 5 is a schematic perspective view showing an example of the image display device of the present invention. As shown in FIG. 5, the image display device 60 of the present invention has a large width of the dark color portion 10 having a trapezoidal shape or a substantially trapezoidal shape at a position facing the front surface of the image display portion 50 with the filter 100 of the present invention. It is arranged so that the bottom of the side faces the image display unit 50 side. By providing the filter of the present invention, the image contrast in the presence of external light can be improved. In addition, the code | symbol 40 in FIG. 5 is an optical filter provided in the observer side of the filter 100. FIG.

  Examples of the image display device to be applied include a plasma panel display device (PDP), a cathode ray tube display device (CRT), a liquid crystal display device (LCD), an electroluminescent display device (EL), and the like. Suitable for use.

  When the filter 100 is directly bonded to the observer side of the image display unit 50, the image display unit 50 and the filter 100 may be bonded via an adhesive layer, or another optical filter and an adhesive layer may be bonded. You may stick together. A so-called pressure-sensitive adhesive is also a form of the adhesive referred to in the present application.

  As described above, according to the image display device 60 of the present invention, since the filter 100 according to the present invention is provided on the image display unit 50 side, the quality and contrast of the display image can be improved. In particular, since the dark color portion 10 having a trapezoidal shape or a substantially trapezoidal shape is arranged so that the base of the larger width faces the image display portion 50 side, the dark color portion 10 can effectively absorb external light.

Hereinafter, the present invention will be described more specifically with reference to examples.
Hereinafter, the present invention will be specifically described with reference to examples. These descriptions do not limit the present invention. In the examples, parts represent parts by weight unless otherwise specified.

Example 1
First, a 188 μm-thick polyethylene terephthalate (PET) sheet (manufactured by Toyobo Co., Ltd .; product name A4300) subjected to a double-sided easy adhesion treatment is prepared as a transparent support 6, and an ultraviolet curing made of a urethane acrylate prepolymer is provided thereon. An adhesive resin was applied to a thickness of 300 μm to form an uncured transparent substrate. A metal shaping roll that can form a groove-shaped recess 3 having an opening width of 20 μm and a depth of 120 μm on the side where the groove-shaped recess 3 is formed with a pitch of 70 μm is pressed against the surface of the uncured transparent substrate. The transparent resin 4 was cured by irradiating ultraviolet rays from the back side while carving a desired groove-like recess shape. Thus, the groove-shaped recess 3 having an opening width of 20 μm and a depth of 120 μm on the side where the groove-shaped recess 3 was formed with a pitch of 70 μm was formed. In addition, since the groove-shaped recessed part 3 is formed in the circumferential direction, the shaping type | mold roll forms the groove-shaped recessed part 3 so that it may extend in the longitudinal direction of a sheet member by rotating on a sheet member. be able to.

  Next, in 100 parts by mass of a transparent acrylic ultraviolet curable prepolymer, 50 parts by mass of black spherical bead-like particles having a minimum particle size of 2 μm and a maximum particle size of 3 μm, 1-hydroxy-cyclohexyl-phenyl-ketone (product (Name: Irgacure 184, manufactured by Ciba Specialty Chemicals) 2 parts by mass were mixed to prepare a liquid ultraviolet curable resin composition 7. This liquid resin composition 7 was applied onto the groove-like recess forming surface side of the transparent substrate 4 having the groove-like recesses formed as described above, and then wiped with a doctor blade 72. At the time of wiping, the transparent resin 2 which is an ultraviolet curable resin was cured by irradiating ultraviolet rays from the back side at the same time. In the wiping, the gap between the flat portion 8 of the transparent substrate 4 and the doctor blade 72 was set to 1.5 μm, and the wiping was repeated twice. As a result, the groove-shaped recess 3 is filled with the UV resin as the transparent resin 2 and the black spherical beads as the dark particles 1, while only the transparent resin 2 remains on the flat portion 8 with a thickness of 1.5 μm. The transparent resin 2 was cured by simultaneous UV irradiation to form a transparent protective layer 2L having a thickness of 1 μm. In this way, the filter 100 of Example 1 was obtained. In the above, [refractive index of transparent resin] − [refractive index of spherical beads] = − 0.003.

(Comparative Example 1)
In Example 1, instead of the spherical bead-shaped particles, black spherical bead-shaped particles having a minimum particle diameter of 0.2 μm and a maximum particle diameter of 3 μm were used, and the same procedure as in Example 1 was performed. A filter was obtained.

(Evaluation)
As a result of observing the flat part 8 of the filter obtained in Example 1 and Comparative Example 1 by magnifying with a microscope, the filter of Example 1 did not have black spherical beads on the flat part 8 which is the translucent region 20. However, the filter of Comparative Example 1 had black spherical beads on the flat portion 8.

1A is a schematic cross-sectional view showing an example of an image contrast enhancement filter of the present invention, and FIG. It is a perspective view of the image contrast improvement filter of this invention provided with the transparent support body. It is typical sectional drawing which shows the other example of the image contrast improvement filter of this invention. It is a process flow figure showing an example of a manufacturing method of a filter of the present invention. It is a typical perspective view which shows an example of the image display apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dark particle 2 Transparent resin 2L Transparent protective layer 3 Groove-shaped recessed part 4 Transparent base material 5 Slope 6 Transparent support 7 Liquid resin composition 8 Flat part 10 Dark color part 20 Translucent area | region 40A, 40B Optical filter 50 Image display apparatus 60 Image display portion 100, 100A, 100B Filter dmin Minimum particle size of dark particles dmax Maximum particle size of dark particles t Transparent protective layer thickness t 'Thickness of transparent resin on flat portion H Depth of groove-like recess W Groove Maximum width of concave part P Normal line θ Angle between slope and normal line

Claims (6)

Adjacent to one side of the transparent base material is a linear portion arranged in parallel along the in-plane direction of the transparent base material, and a dark colored portion having a trapezoidal or substantially trapezoidal cross-sectional shape perpendicular to the extending direction. An image contrast enhancement filter having a translucent region between the dark color portions,
The dark color portion is filled with dark particles and a transparent resin in a groove-like recess having a trapezoidal or substantially trapezoidal cross-sectional shape,
The translucent region has a surface covered with a transparent protective layer made of a transparent resin,
Between the minimum particle size dmin and the maximum particle size dmax of the dark particles, the thickness t of the transparent protective layer, and the maximum width W and depth H of the groove-shaped recess, t <dmin <dmax <W, An image contrast enhancement filter characterized by satisfying a relationship of t <dmin <dmax <H.   The image contrast improving filter according to claim 1, wherein a transparent support is further laminated on the surface of the transparent base material on the non-forming side of the transparent protective layer.   3. An image contrast enhancement filter comprising one or more optical filters on one surface and / or the other surface of the image contrast enhancement filter according to claim 1 or 2.   The image contrast enhancement filter according to claim 1 or 2 is disposed at a position facing the front surface of the image display unit, and a base having a larger width of a dark color portion having a trapezoidal shape or a substantially trapezoidal shape faces the image display portion side. An image display device characterized by comprising: A step of preparing a transparent base material formed with a groove-shaped concave portion having a trapezoidal or substantially trapezoidal cross-sectional shape that is arranged in parallel along the in-plane direction of one surface and orthogonal to the extending direction. When,
Applying a liquid resin composition having dark particles and a transparent resin to the surface on which the groove-shaped recess is formed;
The applied liquid resin composition is scraped off, and the dark color particles and the transparent resin are filled in the groove-like recesses, and the dark color particles are not present in flat portions other than the groove-like recesses. Leaving the transparent resin in a predetermined thickness;
Solidifying the transparent resin, making the groove-like recess a dark color part, and making the flat part a translucent region covered with a transparent protective layer having a predetermined thickness,
Between the minimum particle size dmin and the maximum particle size dmax of the dark color particles, the thickness t ′ of the transparent resin remaining in the flat portion, and the maximum width W and depth H of the groove-shaped recess, t ′ < A method for producing an image contrast enhancement filter, wherein dmin <dmax <W and t ′ <dmin <dmax <H.   The method for producing an image contrast enhancement filter according to claim 5, wherein the predetermined thickness t ′ of the transparent resin is formed to be equal to or greater than the predetermined thickness t of the transparent protective layer.

Images