WO2009116429A1 - 光制御フィルム、これを用いたバックライト装置および凹凸パターン形成用型の作製方法 - Google Patents
光制御フィルム、これを用いたバックライト装置および凹凸パターン形成用型の作製方法 Download PDFInfo
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- WO2009116429A1 WO2009116429A1 PCT/JP2009/054523 JP2009054523W WO2009116429A1 WO 2009116429 A1 WO2009116429 A1 WO 2009116429A1 JP 2009054523 W JP2009054523 W JP 2009054523W WO 2009116429 A1 WO2009116429 A1 WO 2009116429A1
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- light control
- convex
- convex portions
- circular bottom
- control film
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/02—Diffusing elements; Afocal elements
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members
Definitions
- the present invention relates to a backlight device such as a liquid crystal display, a light control film used for illumination, and a backlight device using the same.
- edge light type or direct type backlight devices have been used as light sources for liquid crystal displays.
- Edge-light type backlight devices are used in notebook computers and the like because the thickness of the backlight itself can be reduced, and direct-type backlight devices are often used in large liquid crystal televisions and the like.
- a light control film that collects the light from the backlight device has been incorporated in order to collect the light that is inclined from the front direction in the front direction and improve the front luminance.
- a prism sheet has been used as one of light control films that achieve such an object.
- the prism sheet has a fine regular structure of about several tens of ⁇ m, and although it has a high light condensing property, it generates glare, and when incorporated in a backlight device, moire is generated between the pixels of the liquid crystal panel. This causes a problem that the image quality is deteriorated. Therefore, the occurrence of glare and moire of the light source is suppressed by placing a diffusion film on the prism sheet.
- the front luminance is lowered and the number of parts is increased by placing the diffusion film.
- a light control film different from the prism sheet there is a light control film that can improve the luminance in the front direction of the backlight device by the uneven shape formed on the surface, and can uniformly emit light from the backlight device.
- Patent Document 1 proposes a fine convex shape having a substantially circular bottom surface. Such a convex shape is formed by, for example, a photolithography method, a printing method, or the like (Patent Documents 1 and 2).
- the bottom surface is a convex portion having substantially the same diameter. It is preferable.
- the best way to increase the front brightness by the projections is the close-packed arrangement in which the projections do not overlap each other and are arranged without gaps. In this arrangement, the rule is the same as in the prism sheet example described above. It becomes a structure.
- JP 2004-33811 A (Embodiment of the Invention) Japanese Patent Laid-Open No. 2003-270412 (conventional technology)
- an object of the present invention is to provide a light control film capable of preventing moiré when superimposed on a member having another regular structure while ensuring sufficient front luminance, and a backlight device using the same.
- the present inventor for the above-described problems, has a front / rear pattern that is designed using a unique method for filling the convex portions, while ensuring sufficient front brightness and overlapping with a member having another regular structure.
- the present inventors have found that a light control film capable of preventing moiré can be obtained, and have reached the present invention.
- the light control film of the present invention has a light control layer provided with a concavo-convex pattern having a convex portion having a circular bottom surface of substantially the same diameter on the surface, and the concavo-convex pattern is 1 to n (
- n is an integer greater than or equal to 2)
- the circular bottom surface of the nth (n is an integer greater than or equal to 2) is the first to the (n ⁇ 1) th circular bottom
- the convex portion is arranged so as to be in contact with the circular bottom surface of any one of the first to (n ⁇ 1) th projections without overlapping with the circular bottom surface of the convex portion.
- the ratio of the convex portions arranged so as to be in contact with any circular bottom surface of the two convex portions is 50 to 92%.
- the light control film of the present invention is a light control film having a light control layer provided with a concavo-convex pattern in which a plurality of convex portions having a circular bottom surface of substantially the same diameter are arranged on the surface, wherein the plurality of convex portions Are arranged such that their circular bottom surfaces do not overlap each other and are in contact with the circular bottom surface of one or more other convex portions, and among the plurality of convex portions, the bottom surface is a circular bottom surface of two or more convex portions.
- positioned so that it may contact is 80% or more and less than 100%.
- the regular arrangement means an arrangement that repeats in any direction with the arrangement of any two or more convex portions as a unit.
- the light control film of the present invention is preferably characterized in that the convex portions have substantially the same shape.
- the light control film of the present invention is preferably characterized in that the filling rate of the circular bottom surface of the convex portion in the concave-convex pattern is 70 to 82%.
- the light control film of the present invention is preferably characterized in that the convex portion has an aspect ratio of 0.40 to 0.70.
- the light control film of the present invention is preferably characterized in that the light control layer is composed of a polymer resin.
- the backlight device of the present invention includes a light source, a plate-shaped optical member that emits light incident from the light source from a surface different from the light incident surface, and light disposed in proximity to the plate-shaped optical member.
- the light control film of the present invention is used as the light control film.
- the plate-like optical member is, for example, a light guide plate in which a light source is disposed at one end and a light exit surface is a surface substantially orthogonal to the one end, and the light control film is disposed on the light exit surface of the light guide plate.
- the plate-like optical member is a diffusion plate arranged on one side of the light source, and the light control film is arranged on the opposite side of the diffusion plate from the light source.
- the light control layer is provided with a non-regular concavo-convex pattern on the surface, in which convex portions whose bottom surfaces have substantially the same diameter can be enhanced by a unique filling method. Therefore, it is possible to prevent moiré from being generated even when superimposed on a member having another regular structure while ensuring sufficient front luminance.
- the backlight device of the present invention using such a light control film of the present invention has high front luminance and can be moire-free even when combined with a liquid crystal panel having a regular structure. It becomes possible to have a configuration in which the quality is not lowered and the number of parts is not increased.
- the light control film of the present invention has a light control layer having a concavo-convex pattern on the surface and is characterized by the arrangement of a plurality of convex portions constituting the concavo-convex pattern of the light control layer. Light is incident from the bottom surface side of the convex portion and is emitted toward the concave-convex pattern side (front direction when incorporated in a backlight).
- the plurality of protrusions have a circular bottom surface with substantially the same diameter, and the circular bottom surfaces of one or more other protrusions do not overlap each other. It is arranged to touch.
- the proportion of the convex portions arranged so as to be in contact with any circular bottom surface of two convex portions that are in contact with each other is 50 to 92%.
- connect the circular bottom face of a 2 or more convex part is 80% or more and less than 100%.
- the structure of the light control film of the present invention is not limited to a single light control layer having a concavo-convex pattern on the surface, but may be a structure in which a light control layer is laminated on a support.
- the light control layer of the present invention is mainly composed of a polymer resin.
- the polymer resin include an ionizing radiation curable resin, a thermosetting resin, and a thermoplastic resin.
- the light control layer is used without using fine particles or the like from the viewpoint of suppressing light scattering caused by the difference in refractive index between the substances constituting the light control layer and improving the light collecting property in the front direction. It is preferable to use only a polymer resin.
- ionizing radiation curable resin a photopolymerizable prepolymer that can be crosslinked and cured by irradiation with ionizing radiation (ultraviolet ray or electron beam) can be used.
- An acrylic prepolymer having at least one acryloyl group and having a three-dimensional network structure by crosslinking and curing is particularly preferably used.
- the acrylic prepolymer urethane acrylate, polyester acrylate, epoxy acrylate, melamine acrylate, polyfluoroalkyl acrylate, silicone acrylate and the like can be used.
- these acrylic prepolymers can be used alone, but it is preferable to add a photopolymerizable monomer in order to improve the cross-linking curability and further improve the hardness of the light control layer.
- photopolymerizable monomers examples 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, and diethylene glycol.
- bifunctional acrylic monomer such as diacrylate, polyethylene glycol diacrylate, hydroxypivalate ester neopentyl glycol diacrylate, etc.
- polyfunctional acrylic monomer such as dipentaerythritol hexaacrylate, trimethylpropane triacrylate, pentaerythritol triacrylate or the like Two or more are used.
- the light control layer in addition to the above-mentioned photopolymerizable prepolymer and photopolymerizable monomer, it is preferable to use additives such as a photopolymerization initiator and a photopolymerization accelerator when cured by ultraviolet irradiation.
- additives such as a photopolymerization initiator and a photopolymerization accelerator when cured by ultraviolet irradiation.
- photopolymerization initiator examples include acetophenone, benzophenone, Michler's ketone, benzoin, benzylmethyl ketal, benzoylbenzoate, ⁇ -acyloxime ester, thioxanthone and the like.
- the photopolymerization accelerator can reduce the polymerization obstacle due to oxygen at the time of curing and increase the curing speed.
- p-dimethylaminobenzoic acid isoamyl ester p-dimethylaminobenzoic acid ethyl ester, etc.can be mentioned.
- Thermosetting resins include silicone resins, phenolic resins, urea resins, melamine resins, furan resins, unsaturated polyester resins, epoxy resins, diallyl phthalate resins, guanamine resins, ketone resins, Examples include amino alkyd resins, urethane resins, acrylic resins, and polycarbonate resins. 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.
- a compound such as polyisocyanate, amino resin, epoxy resin, carboxylic acid or the like can be appropriately used in accordance with a suitable resin.
- thermoplastic resins 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 include alcohol, polyvinyl butyral, polyvinyl pyrrolidone, and polyethylene glycol.
- thermosetting resins or thermoplastic resins acrylic thermosetting resins or thermoplastic resins should be used from the viewpoint of obtaining coating strength when used as a light control layer and good transparency. Is preferred.
- thermosetting resins or thermoplastic resins can also be used as thermosetting resins or composite resins in which a plurality of thermoplastic resins are appropriately combined.
- a resin other than the above-described resins can be used in combination as the polymer resin in the light control layer.
- the light control layer includes a lubricant, a fluorescent brightening agent, fine particles, an antistatic agent, a flame retardant, an antibacterial agent, an antifungal agent, and an ultraviolet absorber as long as the effects of the present invention are not impaired.
- a lubricant such as a light stabilizer, an antioxidant, a plasticizer, a leveling agent, a flow regulator, an antifoaming agent, a dispersing agent, a release agent, and a crosslinking agent can also be included.
- the concavo-convex pattern of the light control layer of the present invention is arranged such that the convex portions constituting it are in contact with the circular bottom surfaces of one or more other convex portions without overlapping each other's circular bottom surfaces. ing.
- the proportion of the convex portions arranged so as to be in contact with any circular bottom surface of two convex portions that are in contact with each other is 50 to 92%.
- High front luminance can be ensured by setting the ratio of the convex portions arranged so as to be in contact with any circular bottom surface of the two convex portions in contact with each other to 50% or more.
- the ratio is in the range of 70 to 90%.
- the circular bottom surfaces B to D of the convex portions are in contact with any of the circular bottom surfaces of the two convex portions that are in contact with each other.
- the circular bottom surface B of the convex portion is used as a reference, it is in contact with any of the circular bottom surfaces C and D of the two convex portions that are in contact with each other.
- the circular bottom surface A of the convex portion is in contact with only the circular bottom surface B of the convex portion, the relationship is such that the circular bottom surface of the two convex portions in contact with each other is in contact. Not. Therefore, when all the circular bottom surfaces A to D of the convex portion are examined, the above-mentioned ratio is 75%.
- the convex portions when arranging the convex portions, it is possible to further improve the front luminance by arranging the convex portions so as not to generate a gap that can further arrange the convex portions having a circular bottom surface with substantially the same diameter. It is preferable from the viewpoint.
- FIG. 2A a method for filling the convex portions for realizing the above-described arrangement will be described.
- a method for arranging a plurality of circles on a plane will be described.
- a circle A having a radius r is arranged at an arbitrary position as the first circle.
- the second circle B does not overlap the circle A, and the circle A It arrange
- the position where the third circle C is arranged so as not to overlap with the circles A and B and in contact with either the circle A or the circle B is a position on the line indicated by the dotted line in FIG. .
- C touches both circle A and circle B.
- the fourth circle D touches any one of the circle A, the circle B, and the circle C.
- the positions arranged in this way are the positions on the lines indicated by dotted lines in FIG.
- Three points p1, p2, and p3 on this line are positions where the circle D contacts two or more circles.
- FIG. 2 (e) if the circle D is arranged at the point p3, four circles are arranged as positions where the fifth circle can be arranged as shown by a dotted line in FIG. 2 (f).
- positions where the next circle can be arranged so as to contact one of the circles are defined in a line shape around the circle, and the line contacts two circles.
- the position that will be defined is defined as a point.
- this line is called an arrangement line, and a point is called a specific point.
- circles are arranged on the arrangement line determined by the arrangement of the circles filled up to that point, and at that time, the ratio of arrangement at specific points is controlled. Such circle arrangement is repeated until there are no arrangement lines in the plane where the circle is to be arranged.
- the circle can be arranged in a desired plane without leaving a gap for filling the circle of the same diameter, and all the circles are in contact with any one of the circles without overlapping. Placed in.
- the ratio of the circle that finally touches the two or more circles substantially coincides with the ratio at which the circle is arranged at a specific point.
- the ratio of the circles in contact with two or more circles can be controlled.
- the specific point is a position that touches two or more circles.
- only a position that touches any two of the circles that are in contact with each other may be the specific point.
- only p1 and p3 are specific points
- only p1, p4, and p5 are specific points.
- the ratio of the circles arranged at the specific points determined in this way substantially matches the ratio of the circles arranged so as to be in contact with both of the two circles that finally contact each other.
- FIG. 3 shows an example of a specific flow of the above operation.
- a matrix is set to a predetermined area, and coordinates (x, y) of each grid point are registered.
- the radius r of the circle to be arranged is set.
- the ratio R of the convex portions (circles) in contact with the two or more convex portions (circles) is set (step 301).
- the roughness of the matrix is not particularly limited, but for example, it is preferable that the lattice spacing is 1/20 or less of the radius r of the arranged circle.
- the center of a circle with a radius r (first circle) is placed at a predetermined position (x1, y1), and the pixel value inside it is set to black (step 302).
- the position to be the starting point may be set by the user or may be determined in advance on a predetermined grid on the matrix.
- a lattice point on a circle (arrangement line) having a radius 2r centered on the position (x1, y1) is searched and stored as a set A of arrangement point candidates (step 303).
- the second and subsequent circles are arranged at positions (xi, yj) selected from the set A based on a predetermined selection criterion described later (step 304).
- the coordinates for the next circle placement are determined from the set A of placement point candidates and the set B of specific points (step 307).
- the coordinates are determined so that the ratio of selecting the next coordinates from the set B becomes the initially set value R. For example, if the ratio to be selected from the set B is 1/2 (50%), when 2n circles are arranged, the n circles are changed from the set A (excluding the set B) to the remaining n pieces. Circles select coordinates to be placed from set B. If it is 80%, the arrangement position of four circles out of the five circles arranged sequentially is selected from the set B.
- the criteria for selecting specific coordinates from the set A of arrangement point candidates and the set B of specific points are not particularly limited.
- a random number or the like may be used, and the x coordinate or y coordinate may be at the position (x1, y1). You may make it follow the selection criteria determined suitably, such as selecting the nearest position.
- step 308 The above steps 304 to 307 are repeated until there is no arrangement line in the set area (step 308), and finally the circle can be filled in the area without a gap for adding a new circle.
- the final filling rate of the circles arranged in this way can be obtained by calculating the ratio of the area filled in black to the set area.
- the concave / convex pattern does not have a regular structure, and the filling rate of the convex portions is higher than the filling rate using conventional random numbers (at most 50%). Therefore, a remarkable effect that moire can be prevented while the front luminance is sufficient is exhibited.
- the diameter of the circular bottom surface of the convex portion constituting the concavo-convex pattern is preferably 100 ⁇ m or less as an upper limit, more preferably 80 ⁇ m or less, considering use in combination with a liquid crystal panel.
- the lower limit is preferably 1 ⁇ m or more, and more preferably 3 ⁇ m or more.
- the shape of the convex portion is not particularly limited as long as it has a shape suitable for enhancing the light condensing property on the concave and convex pattern side (front direction of the backlight).
- FIG. Examples thereof include a part of a sphere and a spheroid as shown in (a) to (c), and a rotating body of a line segment having a specific inclination as described in JP-A-2004-280044.
- the aspect ratio of the convex portion is preferably 0.40 to 0.70, and 0.50 to 0.60 from the viewpoint of securing higher front luminance. More preferably.
- the plurality of convex portions have substantially the same shape in both bottom shape and cross-sectional shape.
- the concavo-convex pattern has a filling rate of 70 to 82% of the circular bottom surface of the convex portion from the viewpoint of satisfactorily preventing moiré when superimposed on a member having another regular structure while ensuring sufficient front luminance. It is preferable to do. Furthermore, from the same viewpoint, it is more preferable that the filling rate of the circular bottom surface of the convex portion is 75 to 80%. In the above-described convex arrangement method, the filling rate can be adjusted by adjusting the ratio of selecting the set B of specific points.
- the convex portion having a diameter large enough to enter the gap portion is formed in a gap portion formed between the convex portions (large convex portions) arranged by the convex portion arrangement method of the present invention.
- a convex part smaller than the part (large convex part) can also be arranged. Since the convex portions (large convex portions) are arranged without regularity, the gap portions thereof are not regular, and even if small convex portions are arranged in the gap portions, the arrangement is not regular, and moire is generated. It does not hinder the preventive effect.
- the shape of the small convex portion is not particularly limited, but it is preferable that the shape is substantially similar to the convex portion (large convex portion) from the viewpoint of further improving the light collecting property.
- Such a concavo-convex pattern can be formed by a mold having a concavo-convex pattern complementary to the concavo-convex pattern.
- a method for producing a mold having a concavo-convex pattern complementary to the concavo-convex pattern of the present invention is not particularly limited.
- a cutting tool having a specific cross-sectional shape at the tip using a fine drilling technique is used as a molding die (female die).
- a concave portion having a specific shape is formed on a flat plate by a laser fine processing technique, and this is used as a molding die (female die).
- the thickness of the light control layer is preferably 10 to 300 ⁇ m. By setting the thickness to 10 ⁇ m or more, it is possible to prevent interference unevenness caused by thickness unevenness of the light control layer. On the other hand, handling property can be made favorable by thickness being 300 micrometers or less. Note that the thickness of the light control layer here refers to the thickness from the tip of the convex portion to the opposite surface of the light control layer.
- a highly transparent material such as a glass plate or a plastic film can be used as the support.
- a glass plate it is possible to use a glass plate made of oxide glass such as silicate glass, phosphate glass, borate glass, etc., especially silicate glass, alkali silicate glass, soda lime glass, A silicate glass such as potash lime glass, lead glass, barium glass, borosilicate glass or the like is preferably used as a plate glass.
- plastic film for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyethylene, polypropylene, polystyrene, triacetyl cellulose, acrylic, polyvinyl chloride, norbornene compound, etc. can be used, and stretch processing, particularly biaxial stretching.
- Polyethylene terephthalate film is preferably used because of its excellent mechanical strength and dimensional stability. It is preferable to use a support that has been subjected to an easy adhesion treatment such as a plasma treatment, a corona discharge treatment, a far-ultraviolet irradiation treatment, or an undercoat easy adhesion layer.
- the thickness of the support is not particularly limited and can be appropriately selected depending on the material to be applied. However, considering the handleability as a light control film, it is generally about 25 to 500 ⁇ m, preferably 50 to 300 ⁇ m. Degree.
- a method of forming a light control film provided with the light control layer of the present invention it can be formed by a transfer shaping technique such as 2P (Photo-Polymer) method, embossing method or the like.
- 2P Photo-Polymer
- the polymer resin or the like constituting the light control layer described above is filled in a mold having a concavo-convex pattern complementary to the required concavo-convex pattern, the pattern is transferred, and the polymer resin is then transferred. Etc. is cured and peeled from the mold to obtain a light control film including a light control layer in which a concavo-convex pattern is formed.
- the 2P method it is preferable to employ the 2P method from the viewpoint that the optical film can be produced in a relatively short time and heating and cooling are not required, so that deformation of the constituent members due to heat can be reduced.
- the embossing method it is preferable to employ the viewpoint of a high degree of freedom in the material selectivity of the constituent members and the ability to reduce process costs.
- a light control film can be obtained using photolithography technology. That is, the light control layer is made of an ionizing radiation curable resin, and the ionizing radiation curable resin is irradiated with the ionizing radiation through a mask member including a portion through which the ionizing radiation is transmitted and a portion through which the ionizing radiation is not transmitted. After forming the exposed portion, the ionizing radiation curable resin in the unexposed portion can be removed to obtain a light control film having a light control layer on which the concavo-convex pattern is formed.
- the polymer resin when the polymer resin is an ionizing radiation curable resin, it can be cured by irradiating with electron radiation. Further, when the polymer resin is a thermosetting resin, it can be cured by applying heat.
- the ionizing radiation include ultraviolet rays emitted from ultra high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arcs, metal halide lamps, etc., and ultraviolet rays having a wavelength region of 200 to 400 nm, scanning type and curtain type.
- An electron beam emitted from an electron beam accelerator having a wavelength region of 100 nm or less can be used.
- the light control film of the present invention has an irregular pattern in which the bottom surface has convex portions with substantially the same diameter arranged by a unique method on the surface, and thus has another regular structure while ensuring sufficient front luminance. It can be set as the light control film which can prevent the moire at the time of overlapping with a member.
- a light control film is suitably used as a backlight device such as a liquid crystal display or illumination.
- the backlight device of the present invention comprises at least the light control film of the present invention and a light source.
- the direction of the light control film in the backlight device is not particularly limited, it is preferably used so that the surface having the concavo-convex pattern is on the light emitting surface side.
- the backlight device preferably employs a so-called edge light type or direct type.
- the edge light type backlight device includes a light guide plate, a light source arranged at least at one end of the light guide plate, a light control film of the present invention arranged on the light emitting surface side of the light guide plate, and the like.
- the light control film is preferably used so that the surface having the concavo-convex pattern becomes the light exit surface.
- An optical member such as a prism sheet can also be used between the light guide plate and the light control film.
- the light guide plate is a substantially flat plate shaped so that at least one side surface is a light incident surface and one surface substantially orthogonal to the light incident surface is a light output surface, and is mainly highly transparent such as polymethyl methacrylate.
- a matrix resin selected from various resins. Resin particles having a refractive index different from that of the matrix resin may be added as necessary.
- Each surface of the light guide plate may have a complicated surface shape instead of a uniform plane, or may be provided with diffusion printing such as a dot pattern.
- the light source is disposed at least at one end of the light guide plate, and a cold cathode tube, an LED light source, or the like is mainly used.
- Examples of the shape of the light source include a dot shape, a line shape, and an L shape.
- the edge light type backlight device includes a reflection plate, a polarizing film, an electromagnetic wave shielding film, and the like depending on the purpose.
- FIG. 5 shows an embodiment of the edge light type backlight device of the present invention.
- the backlight device 140 has a configuration in which a light source 142 is provided on both sides of the light guide plate 141, and light control is performed so that the surface having the concavo-convex pattern on the upper side of the light guide plate 141 is opposite to the light guide plate.
- a film 143 is placed.
- the light source 142 is covered with a light source reflector 144 except for a portion facing the light guide plate 141 so that light from the light source is efficiently incident on the light guide plate 141.
- a reflection plate 146 housed in the chassis 145 is provided below the light guide plate 141.
- the direct type backlight device includes the light control film of the present invention and a diffusion plate, a light source, and the like, which are sequentially provided on the surface opposite to the light exit surface of the light control film.
- the light control film is preferably used so that the surface having the concavo-convex pattern becomes the light exit surface.
- An optical member such as a prism sheet can also be used between the diffusion plate and the light control film.
- the diffuser plate is for erasing the lamp pattern of the light source.
- the transparent film (lighting curtain) with the dot pattern formed on the part corresponding to the light source the uneven light diffusion on the transparent substrate So-called light diffusion films having layers can be used alone or in appropriate combination.
- the light source may be the same as that used in the above-described edge light type backlight device.
- the direct type backlight device may include a reflection plate, a polarizing film, an electromagnetic wave shielding film, and the like depending on the purpose.
- FIG. 6 shows an embodiment of a direct backlight device according to the present invention.
- a direct backlight device 150 as shown in the figure, a plurality of light sources 152 are arranged on a reflection plate 156 housed in a chassis 155, and a light control film 153 is placed thereon via a diffusion plate 151. It has a structure.
- the backlight device of the present invention uses a light control film having a surface having a specific uneven pattern on the surface as a light control film for controlling the direction of light emitted from a light source or a light guide plate, the front luminance is increased. Even when used in combination with a liquid crystal panel having a regular structure, the image quality can be improved without generating moiré. Further, it is not necessary to increase the number of parts for improving the quality of the backlight device.
- Example 1 Production of light control film [Example 1] Using a mold a capable of forming and transferring a specific uneven shape formed by a micro-drilling technique, 50 parts of acrylic monomer (methyl methacrylate: Wako Pure Chemical Industries, Ltd.) as a light control layer forming liquid on the mold a ), 45 parts of polyfunctional acrylic monomer (NK Ester A-TMPT-3EO: Shin-Nakamura Chemical Co., Ltd.), 5 parts of photopolymerization initiator (Irgacure 184: Ciba Japan Co., Ltd.) are filled with the mixture.
- acrylic monomer methyl methacrylate: Wako Pure Chemical Industries, Ltd.
- polyfunctional acrylic monomer NK Ester A-TMPT-3EO: Shin-Nakamura Chemical Co., Ltd.
- photopolymerization initiator Irgacure 184: Ciba Japan Co., Ltd.
- the light control film of Example 1 was prepared.
- the mold a used in Example 1 is designed as a concavo-convex pattern in which convex portions having a circular bottom surface with substantially the same diameter of 50 ⁇ m are filled at a filling rate of 80% according to the method for arranging convex portions of the present invention. This is produced by forming a concave portion complementary to the convex portion of the concave-convex pattern on the surface of the mold material.
- the shape of the convex part is a mountain shape as shown in FIG. 4C, the aspect ratio is 0.60, and the convex part is in contact with any circular bottom surface of two convex parts in contact with each other.
- the ratio of the convex portions arranged in this manner was designed to be 89%.
- Example 2 instead of the mold a used in the first embodiment, the same procedure as in the first embodiment except that the mold b capable of shaping and transferring a specific uneven shape formed by the fine hole drilling technique is used.
- the light control film of Example 2 was produced.
- the mold b used in Example 2 was designed to have a concavo-convex pattern in which convex portions having a circular bottom surface with substantially the same diameter of 50 ⁇ m were filled at a filling rate of 73% in accordance with the convex portion arranging method of the present invention. This is produced by forming a concave portion complementary to the convex portion of the concave-convex pattern on the surface of the mold material.
- the shape of the convex part is a mountain shape as shown in FIG. 4C, the aspect ratio is 0.45, and the convex part is in contact with any circular bottom surface of the two convex parts in contact with each other.
- the ratio of convex portions arranged in this way was designed to be 72%.
- FIG. 7 shows the arrangement of the convex portions of the concave / convex pattern designed in this example.
- Example 3 In place of the mold a used in Example 1, a mold c capable of shaping and transferring a specific concavo-convex shape formed by a fine hole drilling technique was used in the same manner as in Example 1, The light control film of Example 3 was produced.
- the mold c used in Example 3 is designed to have a concavo-convex pattern in which convex portions having a circular bottom surface with substantially the same diameter of 50 ⁇ m are filled at a filling rate of 70% according to the method for arranging convex portions of the present invention. This is produced by forming a concave portion complementary to the convex portion of the concave-convex pattern on the surface of the mold material.
- the shape of the convex part is a mountain shape as shown in FIG. 4C, the aspect ratio is 0.50, and the convex part is in contact with any circular bottom surface of two convex parts in contact with each other.
- the ratio of the convex portions arranged in this manner was designed to be 57%.
- Example 4 Using a mold d capable of shape-transferring a specific uneven shape formed by the fine hole drilling technique, the mold d was filled with the same light control layer forming liquid as in Example 1. Thereafter, the light control layer is irradiated with 600 mJ / cm 2 of ultraviolet light from a high-pressure mercury lamp to cure the light control layer, and is peeled off from the mold d, whereby the light control film of Example 4 comprising the light control layer having a thickness of 70 ⁇ m. Was made.
- the mold d used in Example 4 was designed to have a concavo-convex pattern in which convex portions having a circular bottom surface with substantially the same diameter of 50 ⁇ m were filled at a filling rate of 75% according to the method for arranging convex portions of the present invention. This is produced by forming a concave portion complementary to the convex portion of the concave-convex pattern on the surface of the mold material.
- the shape of the convex part is a mountain shape as shown in FIG. 4C, the aspect ratio is 0.35, and the convex part is in contact with any circular bottom surface of two convex parts in contact with each other.
- the ratio of convex portions arranged in this manner was designed to be 79%.
- Example 5 instead of the mold d used in Example 4, the same procedure as in Example 4 was used except that a mold e capable of shaping and transferring a specific uneven shape formed by a fine drilling technique was used.
- the light control film of Example 5 was produced.
- the mold e used in Example 5 was designed to have a concavo-convex pattern in which convex portions having a circular bottom surface with substantially the same diameter of 50 ⁇ m were filled at a filling rate of 69% according to the method for arranging convex portions of the present invention. This is produced by forming a concave portion complementary to the convex portion of the concave-convex pattern on the surface of the mold material.
- the shape of the convex part is a mountain shape as shown in FIG. 4C, the aspect ratio is 0.55, and the convex part is in contact with any circular bottom surface of the two convex parts in contact with each other.
- the ratio of the convex portions arranged in this way was designed to be 51%.
- a 35 ⁇ m thick light control layer is shaped and transferred onto a 188 ⁇ m thick polyethylene naphthalate film (Teonex Q51: Teijin DuPont Films, Inc.) as a support to form a light control layer on the support.
- the light control film was prepared under conditions of a cylinder temperature of 280 degrees and a mold temperature of 85 degrees.
- the light control layer was configured using pellets of polycarbonate resin (Panlite L-1225: Teijin Chemicals) as a polymer resin.
- a mold f capable of forming and transferring a specific uneven shape formed by a fine drilling technique was used.
- the mold f used in Example 6 is designed to have a concavo-convex pattern in which convex portions having a circular bottom surface with substantially the same diameter of 50 ⁇ m are filled at a filling rate of 76% according to the method for arranging convex portions of the present invention. This is produced by forming a concave portion complementary to the convex portion of the concave-convex pattern on the surface of the mold material.
- the shape of the convex part is a mountain shape as shown in FIG. 4C, the aspect ratio is 0.50, and the convex part is in contact with any circular bottom surface of two convex parts in contact with each other.
- the ratio of convex portions arranged in this manner was designed to be 83%.
- Example 7 instead of the mold f used in Example 6, the same procedure as in Example 6 was used except that a mold g capable of shaping and transferring a specific uneven shape formed by the fine drilling technique was used.
- the light control film of Example 7 was produced.
- the mold g used in Example 7 was designed to have a concavo-convex pattern in which convex portions having a circular bottom surface with substantially the same diameter of 50 ⁇ m were filled at a filling rate of 72% according to the method for arranging convex portions of the present invention. This is produced by forming a concave portion complementary to the convex portion of the concave-convex pattern on the surface of the mold material.
- the shape of the convex part is a mountain shape as shown in FIG. 4C, the aspect ratio is 0.65, and the convex part is in contact with any circular bottom surface of the two convex parts in contact with each other.
- the ratio of convex portions arranged in this way was designed to be 68%.
- Example 8 instead of the mold f used in Example 6, the same procedure as in Example 6 was used except that a mold h capable of shaping and transferring a specific uneven shape formed by the fine drilling technique was used.
- the light control film of Example 8 was produced.
- the mold h used in Example 8 was designed to have a concavo-convex pattern in which convex portions having a circular bottom surface with substantially the same diameter of 50 ⁇ m were filled at a filling rate of 81% according to the method for arranging convex portions of the present invention. This is produced by forming a concave portion complementary to the convex portion of the concave-convex pattern on the surface of the mold material.
- the shape of the convex part is a mountain shape as shown in FIG. 4C, the aspect ratio is 0.60, and the convex part is in contact with any circular bottom surface of two convex parts in contact with each other.
- the ratio of the convex portions arranged in this manner was designed to be 90%.
- Example 9 Using an injection molding machine, a light control film composed of a light control layer having a thickness of 30 ⁇ m was produced under conditions of a cylinder temperature of 280 degrees and a mold temperature of 85 degrees.
- the light control layer was configured using pellets of polycarbonate resin (Panlite L-1225: Teijin Chemicals) as a polymer resin.
- a mold i capable of shape-transferring a specific uneven shape formed by a fine drilling technique was used.
- the mold i used in Example 9 was designed to have a concavo-convex pattern in which convex portions having a circular bottom surface with substantially the same diameter of 50 ⁇ m were filled at a filling rate of 78% according to the method for arranging convex portions of the present invention.
- the shape of the convex part is a mountain shape as shown in FIG. 4C, the aspect ratio is 0.75, and the convex part is in contact with any circular bottom surface of two convex parts in contact with each other.
- the ratio of the convex portions arranged in this manner was designed to be 87%.
- Example 10 instead of the mold i used in Example 9, the same procedure as in Example 9 was used except that a mold j capable of shaping and transferring a specific uneven shape formed by the fine drilling technique was used.
- the light control film of Example 10 was produced.
- the mold j used in Example 10 was designed to have a concavo-convex pattern in which convex portions having a circular bottom surface with substantially the same diameter of 50 ⁇ m were filled at a filling rate of 83% according to the method for arranging convex portions of the present invention. This is produced by forming a concave portion complementary to the convex portion of the concave-convex pattern on the surface of the mold material.
- the shape of the convex part is a mountain shape as shown in FIG. 4C, the aspect ratio is 0.50, and the convex part is in contact with any circular bottom surface of two convex parts in contact with each other.
- the ratio of the convex portions arranged in this way was designed to be 92%.
- Comparative Example 1 instead of the mold a used in Example 1, the same procedure as in Example 1 was used except that a mold k capable of shaping and transferring a specific concavo-convex shape formed by a fine drilling technique was used.
- the light control film of Comparative Example 1 was produced.
- the mold k used in Comparative Example 1 is a convex portion having a circular bottom surface with substantially the same diameter of 50 ⁇ m, and the convex portions having substantially the same shape and an aspect ratio of 0.50 are closely packed without overlapping each other.
- the concavo-convex pattern formed (filling rate: 91%) is designed to be shaped and transferred.
- the mold k Since the mold k is designed so that the convex portions are closely packed, all the convex portions of the concavo-convex pattern are formed on the surface of the light control layer of the light control film produced by the mold k. It was arrange
- Comparative Example 2 instead of the mold a used in Example 1, the same procedure as in Example 1 was used except that a mold l capable of shaping and transferring a specific uneven shape formed by a fine drilling technique was used. The light control film of Comparative Example 2 was produced. Note that the mold 1 used in Comparative Example 2 has a circular bottom surface with substantially the same diameter of 50 ⁇ m, and a convex portion having a substantially identical shape with an aspect ratio of 0.60 is randomly generated using a random number without overlapping the circular bottom surfaces. The arranged concavo-convex pattern is designed and manufactured so that the concavo-convex pattern can be shaped and transferred.
- the ratio of the convex portions arranged so as to be in contact with any circular bottom surface of the two convex portions in contact with each other was 0.1% or less. .
- the filling factor of the circular bottom face of the convex portion was 54%.
- Comparative Example 3 instead of the mold f used in Example 6, the same procedure as in Example 6 was used except that a mold m capable of shaping and transferring a specific uneven shape formed by the fine hole drilling technique was used.
- the light control film of Comparative Example 3 was produced.
- the mold m used in Comparative Example 3 is a convex portion having a circular bottom surface with substantially the same diameter of 50 ⁇ m, and the convex portion having substantially the same shape and an aspect ratio of 0.50 is the arrangement of the convex portions of the present invention. According to the method, it was designed so that a concavo-convex pattern filled with a filling rate of 63% can be shaped and transferred.
- the convex portion arrangement method of the present invention was satisfied. That is, when the first convex portion is arbitrarily selected, the second convex portion is arranged so as to be in contact with the circular bottom surface of the first convex portion without overlapping the first convex portion serving as a reference, and then the third convex portion. Are arranged so as to be in contact with the circular bottom surface of any one of the first to second projections without overlapping with all the first to second projections, and the n-th projection is also referred to hereinafter.
- corrugated pattern was 10%.
- a 15-inch edge light type backlight device (one lamp above and below the cold-cathode tube) constructed by installing the light control films of Examples 1 to 10 and Comparative Examples 1 to 3 on the light guide plate.
- the backlight devices of Examples 1 to 10 and Comparative Examples 1 to 3 were obtained.
- the light control films of Examples 1 to 10 each have a light control layer having a concavo-convex pattern on the surface of which convex portions having substantially the same diameter are arranged on the bottom surface. Therefore, the filling rate of the convex portions could be increased, and the front luminance could be sufficiently secured. Further, even when the light control films of Examples 1 to 10 were used while being superposed on a liquid crystal panel having a regular structure, moire did not occur and the image quality of the liquid crystal display was not impaired.
- the aspect ratio of the protrusions constituting the uneven pattern on the surface of the light control layer is 0.40 to 0.70, and the protrusions of the protrusions Since the filling rate was in the range of 70 to 82%, the balance between front luminance and moiré prevention was excellent.
- the aspect ratio of the convex portions constituting the concavo-convex pattern on the surface of the light control layer is 0.50 to 0.60, and the filling ratio of the convex portions is 75. Since it was in the range of ⁇ 80%, the balance between the front luminance and the moire prevention property was particularly excellent.
- the light control film of Comparative Example 1 is provided with a close-packed concavo-convex pattern in which convex portions having substantially the same diameter are arranged on each other without overlapping each other, unlike the method for arranging convex portions of the present invention. Therefore, the front luminance was excellent.
- the light control film of Comparative Example 1 is used while being superposed on a liquid crystal panel having a regular structure, moire is generated and the image quality of the liquid crystal display is deteriorated.
- the light control film of Comparative Example 2 has a light control layer provided with a concavo-convex pattern in which convex portions having substantially the same diameter are randomly arranged using random numbers, unlike the method of arranging convex portions of the present invention. Therefore, when the light control film of Comparative Example 2 and the liquid crystal panel having a regular structure were overlapped, moire did not occur, and the image quality of the liquid crystal display was not impaired.
- the light control film of Comparative Example 2 was not arranged so that almost all of the convex portions of the concavo-convex pattern on the surface of the light control layer were in contact with any circular bottom surface of the two convex portions in contact ( 0.1% or less), the filling rate of the convex portions was low, and the front luminance was poor.
- the light control film of Comparative Example 3 had a light diffusion layer provided with a concavo-convex pattern in which convex portions were arranged by the same method as the convex portion arranging method of the present invention.
- the proportion of the convex portions arranged so as to be in contact with either circular bottom surface of the two convex portions was 10%, so moire did not occur, but the front luminance was poor It became.
- the backlight devices of Comparative Examples 1 to 3 incorporating the light control films of Comparative Examples 1 to 3 use a light control film having a poor balance between front luminance and moiré prevention as described above. Therefore, the quality as a backlight device was low.
- A, B, C, D ... Circular bottom surface 140, 150 ...
- Light guide plate or diffuser plate 142, 152 ...
- Light source 143, 153 ...
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Abstract
Description
また、本発明の光制御フィルムは、好ましくは凸部が略同一形状であることを特徴とするものである。
前述したように、本発明の光制御層の凹凸状パターンは、それを構成する凸部が、互いの円形底面が重なることなく且つ他の1以上の凸部の円形底面と接するように配置されている。ただし複数の凸部のうち、互いに接する2つの凸部のいずれの円形底面にも接するように配置された凸部の割合は50~92%である。
こうして配置した円の最終的な充填率は、設定された面積に対する、黒に塗りつぶされた面積の割合を算出することにより、求めることができる。
特に凸部のアスペクト比(凸部の高さ/円形底面の直径)は、より高い正面輝度を確保する観点から、0.40~0.70とすることが好ましく、0.50~0.60とすることがより好ましい。
前述した凸部の配置方法においては、特定点の集合Bを選択する割合を調整することにより充填率を調整することができる。
[実施例1]
微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型aを用い、金型aに光制御層形成液としてアクリルモノマー 50部(メタクリル酸メチル:和光純薬社)、多官能性アクリルモノマー 45部(NKエステルA-TMPT-3EO:新中村化学工業社)、光重合開始剤 5部(イルガキュア184:チバ・ジャパン社)の混合液を充填し、その上に支持体として厚み100μmのポリエチレンテレフタレートフィルム(コスモシャインA4100:東洋紡績社)を密着させた。その後、光制御層に対し高圧水銀灯により紫外線を600mJ/cm2照射して光制御層を硬化させ、金型aから剥離することで、支持体上に厚み50μmの光制御層が形成された実施例1の光制御フィルムを作製した。
実施例1で用いた金型aは、略同一直径50μmの円形底面を持つ凸部を、本発明の凸部の配置方法にしたがって、80%の充填率で充填した凹凸パターンを設計し、金型材料表面に、この凹凸パターンの凸部と相補形の凹部を形成することにより作製したものである。凹凸パターンにおいて、凸部の形状は図4(c)に示すような山型であってアスペクト比は0.60とし、凸部のうち、接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合が89%となるように設計した。
実施例1で用いた金型aに換えて、微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型bを用いた以外は実施例1と同様にして、実施例2の光制御フィルムを作製した。なお、実施例2で用いた金型bは、略同一直径50μmの円形底面を持つ凸部を、本発明の凸部の配置方法にしたがって、73%の充填率で充填した凹凸パターンを設計し、金型材料表面に、この凹凸パターンの凸部と相補形の凹部を形成することにより作製したものである。凹凸パターンにおいて、凸部の形状は図4(c)に示すような山型であってアスペクト比は0.45とし、凸部のうち、接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合が72%となるように設計した。本実施例で設計した凹凸パターンの凸部配置を図7に示す。
実施例1で用いた金型aに換えて、微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型cを用いた以外は実施例1と同様にして、実施例3の光制御フィルムを作製した。なお実施例3で用いた金型cは、略同一直径50μmの円形底面を持つ凸部を、本発明の凸部の配置方法にしたがって、70%の充填率で充填した凹凸パターンを設計し、金型材料表面に、この凹凸パターンの凸部と相補形の凹部を形成することにより作製したものである。凹凸パターンにおいて、凸部の形状は図4(c)に示すような山型であってアスペクト比は0.50とし、凸部のうち、接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合が57%となるように設計した。
微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型dを用い、金型dに実施例1と同様の光制御層形成液を充填した。その後、光制御層に対し高圧水銀灯により紫外線を600mJ/cm2照射して光制御層を硬化させ、金型dから剥離することで、厚み70μmの光制御層からなる実施例4の光制御フィルムを作製した。なお、実施例4で用いた金型dは、略同一直径50μmの円形底面を持つ凸部を、本発明の凸部の配置方法にしたがって、75%の充填率で充填した凹凸パターンを設計し、金型材料表面に、この凹凸パターンの凸部と相補形の凹部を形成することにより作製したものである。凹凸パターンにおいて、凸部の形状は図4(c)に示すような山型であってアスペクト比は0.35とし、凸部のうち、接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合が79%となるように設計した。
実施例4で用いた金型dに換えて、微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型eを用いた以外は実施例4と同様にして、実施例5の光制御フィルムを作製した。なお、実施例5で用いた金型eは、略同一直径50μmの円形底面を持つ凸部を、本発明の凸部の配置方法にしたがって、69%の充填率で充填した凹凸パターンを設計し、金型材料表面に、この凹凸パターンの凸部と相補形の凹部を形成することにより作製したものである。凹凸パターンにおいて、凸部の形状は図4(c)に示すような山型であってアスペクト比は0.55とし、凸部のうち、接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合が51%となるように設計した。
支持体として厚み188μmのポリエチレンナフタレートフィルム(テオネックスQ51:帝人デュポンフィルム社)上に、射出成形機を用いて厚み35μmの光制御層を賦形転写し、支持体上に光制御層が形成されてなる光制御フィルムを、シリンダー温度280度、金型温度85度の条件下で作製した。光制御層は、高分子樹脂としてポリカーボネート樹脂(パンライトL-1225:帝人化成社)のペレットを用いて構成した。型は、微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型fを用いた。なお、実施例6で用いた金型fは、略同一直径50μmの円形底面を持つ凸部を、本発明の凸部の配置方法にしたがって、76%の充填率で充填した凹凸パターンを設計し、金型材料表面に、この凹凸パターンの凸部と相補形の凹部を形成することにより作製したものである。凹凸パターンにおいて、凸部の形状は図4(c)に示すような山型であってアスペクト比は0.50とし、凸部のうち、接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合が83%となるように設計した。
実施例6で用いた金型fに換えて、微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型gを用いた以外は実施例6と同様にして、実施例7の光制御フィルムを作製した。なお、実施例7で用いた金型gは、略同一直径50μmの円形底面を持つ凸部を、本発明の凸部の配置方法にしたがって、72%の充填率で充填した凹凸パターンを設計し、金型材料表面に、この凹凸パターンの凸部と相補形の凹部を形成することにより作製したものである。凹凸パターンにおいて、凸部の形状は図4(c)に示すような山型であってアスペクト比は0.65とし、凸部のうち、接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合が68%となるように設計した。
実施例6で用いた金型fに換えて、微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型hを用いた以外は実施例6と同様にして、実施例8の光制御フィルムを作製した。なお、実施例8で用いた金型hは、略同一直径50μmの円形底面を持つ凸部を、本発明の凸部の配置方法にしたがって、81%の充填率で充填した凹凸パターンを設計し、金型材料表面に、この凹凸パターンの凸部と相補形の凹部を形成することにより作製したものである。凹凸パターンにおいて、凸部の形状は図4(c)に示すような山型であってアスペクト比は0.60とし、凸部のうち、接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合が90%となるように設計した。
射出成形機を用いて、厚み30μmの光制御層からなる光制御フィルムを、シリンダー温度280度、金型温度85度の条件下で作製した。光制御層は、高分子樹脂としてポリカーボネート樹脂(パンライトL-1225:帝人化成社)のペレットを用いて構成した。型は、微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型iを用いた。なお、実施例9で用いた金型iは、略同一直径50μmの円形底面を持つ凸部を、本発明の凸部の配置方法にしたがって、78%の充填率で充填した凹凸パターンを設計し、金型材料表面に、この凹凸パターンの凸部と相補形の凹部を形成することにより作製したものである。凹凸パターンにおいて、凸部の形状は図4(c)に示すような山型であってアスペクト比は0.75とし、凸部のうち、接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合が87%となるように設計した。
実施例9で用いた金型iに換えて、微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型jを用いた以外は実施例9と同様にして、実施例10の光制御フィルムを作製した。なお、実施例10で用いた金型jは、略同一直径50μmの円形底面を持つ凸部を、本発明の凸部の配置方法にしたがって、83%の充填率で充填した凹凸パターンを設計し、金型材料表面に、この凹凸パターンの凸部と相補形の凹部を形成することにより作製したものである。凹凸パターンにおいて、凸部の形状は図4(c)に示すような山型であってアスペクト比は0.50とし、凸部のうち、接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合が92%となるように設計した。
実施例1で用いた金型aに換えて、微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型kを用いた以外は実施例1と同様にして、比較例1の光制御フィルムを作製した。なお、比較例1で用いた金型kは、略同一直径50μmの円形底面を持つ凸部であって、略同一形状でアスペクト比が0.50の凸部が、互いに重なり合うことなく最密充填(充填率:91%)された凹凸状パターンを賦形転写できるように設計したものである。金型kは、凸部が最密充填されるように設計したものであるため、金型kにより作製された光制御フィルムの光制御層表面には、凹凸状パターンの凸部のすべてが、接した2つの凸部のいずれの円形底面にも接するように配置されていた。
実施例1で用いた金型aに換えて、微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型lを用いた以外は実施例1と同様にして、比較例2の光制御フィルムを作製した。なお、比較例2で用いた金型lは、略同一直径50μmの円形底面を持ち、アスペクト比が0.60の略同一形状の凸部を、乱数を用いて円形底面が重なり合うことなくランダムに配置した凹凸状パターンを設計し、この凹凸パターンを賦形転写できるように作製したものである。この金型により作製された凹凸パターンでは、凸部のうち、接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合は、0.1%以下であった。また、凸部の円形底面の充填率は54%であった。
実施例6で用いた金型fに換えて、微細穴開け加工技術により形成された特定の凹凸形状を賦形転写することができる金型mを用いた以外は実施例6と同様にして、比較例3の光制御フィルムを作製した。なお、比較例3で用いた金型mは、略同一直径50μmの円形底面を持つ凸部であって、略同一形状でアスペクト比が0.50の凸部が、本発明の凸部の配置方法にしたがって、63%の充填率で充填された凹凸状パターンを賦形転写できるように設計した。
次に、実施例1~10及び比較例1~3の光制御フィルムを導光板上に設置して構成した15インチのエッジライト型バックライト装置(冷陰極管上下各1灯)を作製し、実施例1~10及び比較例1~3のバックライト装置とした。
(1)正面輝度
実施例1~10及び比較例1~3の光制御フィルムを用いたエッジライト型バックライト装置の光出射面中心の正面輝度を測定した。光制御フィルムの向きは、凹凸状パターンを有する面が光出射面となるようにした。測定結果を表1に示す(単位は「cd/m2」)。なお、光制御フィルムを用いない状態でのエッジライト型バックライト装置の正面輝度は、1000cd/m2であった。
暗室にて、実施例1~10及び比較例1~3の光制御フィルムを用いた液晶ディスプレイを全白表示で点灯し、正面および斜め方向からの目視によるモアレの発生状況を観察した。モアレがまったく発生しなかったものを「◎」、モアレが若干発生したものの目視ではほとんど確認できない程度であったものを「○」、モアレが若干発生したが視認性に影響を及ぼさない程度であったものを「△」、モアレが発生し視認性に大きく影響を及ぼしたものを「×」として評価した。評価結果を表1に示す。
140、150・・・バックライト装置
141、151・・・導光板或いは拡散板
142、152・・・光源
143、153・・・光制御フィルム
Claims (10)
- 略同一直径の円形底面を持つ凸部を配置した凹凸状パターンを表面に備えた光制御層を有する光制御フィルムであって、
前記凹凸状パターンは、1からn(nは2以上の整数)番目までの凸部を順次配置したときに、n番目の凸部の円形底面が、1番目から(n-1)番目までのすべての凸部の円形底面と重なることなく、1番目から(n-1)番目までのいずれかの凸部の円形底面と接するように配置されてなるものであり、
前記凸部のうち、接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合が50~92%であることを特徴とする光制御フィルム。 - 前記凸部のうち、その底面が2以上の凸部の円形底面と接するように配置された凸部の割合が80%以上100%以下であることを特徴とする請求項1記載の光制御フィルム。
- 前記凸部は、略同一形状であることを特徴とする請求項1又は2に記載の光制御フィルム。
- 前記凹凸状パターンにおける前記凸部の円形底面の充填率が、70~82%であることを特徴とする請求項1から3何れか1項記載の光制御フィルム。
- 前記凸部のアスペクト比が、0.40~0.70であることを特徴とする請求項1から4何れか1項記載の光制御フィルム。
- 前記光制御層は、高分子樹脂により構成されてなることを特徴とする請求項1から5何れか1項記載の光制御フィルム。
- 表面に凹凸状パターンを備えた光制御層を有する光制御フィルムであって、前記凹凸状パターンは、略同一直径の円形底面を持つ複数の第1の凸部と前記第1の凸部より直径の小さい円形底面を持つ第2の凸部を配置してなり、
前記複数の第1の凸部は、互いの円形底面が重なることなく且つ他の1以上の第1の凸部の円形底面と接するように配置されてなり、
前記複数の第1の凸部のうち、底面が接した2つの凸部のいずれの円形底面にも接するように配置されてなる凸部の割合が50~92%であることを特徴とする光制御フィルム。 - 表面に、略同一直径の円形底面を持つ複数の凸部を配置した凹凸状パターンを備えた光制御層を有する光制御フィルムであって、
前記複数の凸部は、互いの円形底面が重なることなく且つ他の1以上の凸部の円形底面と接するように配置されてなり、
前記複数の凸部のうち、その底面が2以上の凸部の円形底面と接するように配置された凸部の割合が80%以上100%未満であることを特徴とする光制御フィルム。 - 光源と、前記光源から入射した光を、光入射面とは異なる面から出射する板状光学部材と、前記板状光学部材に近接して配置される光制御フィルムとを備えたバックライト装置において、前記光制御フィルムとして、請求項1から8何れか1項記載の光制御フィルムを用いたことを特徴とするバックライト装置。
- 表面に凹凸状パターンを備えた光制御層を有する光制御フィルムの前記凹凸パターン形成用型を作製する方法であって、
型の表面に、略同一直径の円形底面を持つ複数の凸部の底面となる円を配置するステップと、
配置された円の内側に、前記凸部の雌型となる凹部を形成するステップとを有し、
前記円を配置するステップでは、1からn(nは2以上の整数)番目までの円を順次配置するステップを、他の円と重ならずに円を配置することが可能な隙間が前記型の表面になくなるまで行い、その際、n番目に配置される円が、1番目から(n-1)番目までのすべての円と重なることなく、1番目から(n-1)番目までのいずれかの円と接するように配置するとともに、接した2つの円のいずれにも接する位置に配置される円の割合を50~92%に制御することを特徴とする型の作製方法。
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WO2012086651A1 (ja) | 2010-12-21 | 2012-06-28 | 株式会社 きもと | 発光素子用微細構造体、当該微細構造体を用いた発光素子及び照明装置 |
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Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
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Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4924356A (en) * | 1988-12-07 | 1990-05-08 | General Electric Company | Illumination system for a display device |
JPH04277733A (ja) * | 1991-03-06 | 1992-10-02 | Nikon Corp | 焦点板の製造方法 |
US5598280A (en) * | 1993-03-23 | 1997-01-28 | Dai Nippon Printing Co., Ltd. | Film lens and a surface light source using the same |
JP2830972B2 (ja) * | 1995-03-06 | 1998-12-02 | 株式会社日立製作所 | 液晶表示装置 |
JP4243779B2 (ja) * | 1997-11-14 | 2009-03-25 | 株式会社ニコン | 拡散板の製造方法および拡散板、並びにマイクロレンズアレイの製造方法およびマイクロレンズアレイ |
US6636363B2 (en) * | 2002-03-11 | 2003-10-21 | Eastman Kodak Company | Bulk complex polymer lens light diffuser |
JP4133420B2 (ja) * | 2002-03-26 | 2008-08-13 | シャープ株式会社 | バックライト及び液晶表示装置 |
JP2004033811A (ja) * | 2002-06-28 | 2004-02-05 | Hitachi Chem Co Ltd | 表面凹凸形成方法、それにより得られる光学フィルム及び拡散反射板並びに拡散反射板の製造方法 |
US6859326B2 (en) * | 2002-09-20 | 2005-02-22 | Corning Incorporated | Random microlens array for optical beam shaping and homogenization |
US7416309B2 (en) * | 2004-12-30 | 2008-08-26 | 3M Innovative Properties Company | Optical film having a surface with rounded structures |
KR100665871B1 (ko) * | 2005-04-21 | 2007-01-10 | 미래나노텍(주) | 액정표시장치의 백라이트 어셈블리 |
JP2006350177A (ja) * | 2005-06-20 | 2006-12-28 | Seiko Epson Corp | 光学シートの製造方法、光学シート、面状照明装置、電気光学装置 |
-
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WO2012086651A1 (ja) | 2010-12-21 | 2012-06-28 | 株式会社 きもと | 発光素子用微細構造体、当該微細構造体を用いた発光素子及び照明装置 |
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