JP2007071930A - Optical component, manufacturing method of the same, direct type surface light source device provided with the same and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical member which can substantially shield ultraviolet rays while transmitting visible light and has high productivity, to provide a manufacturing method of the optical member, to provide a surface light source device using the optical member, and to provide a display device. <P>SOLUTION: A planar light conversion element has a rugged pattern formed on the surface 3a, wherein light emitted from a primary light source 11 is converted toward a prescribed direction of the surface side, so as to enhance directivity of the light and emit the converted light. The rugged pattern is formed as a cured body 3 of a curable resin which may be cured by ultraviolet rays. Further, the cured body 3 is adhered to a surface of a planar transparent resin support 2 via an ultraviolet curable resin which may be the same as the curable resin. An ultraviolet ray shielding layer 4 which substantially shields ultraviolet rays while transmitting visible light is disposed on a surface of the light conversion element. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical component having a concavo-convex pattern on a surface or inside used for a surface light source device, a display device, and the like, and a method for manufacturing the same.

  Liquid crystal display devices (liquid crystal displays) incorporating a backlight unit as a surface light source device are widely used. In such a liquid crystal display device, light emitted from a surface light source device such as a backlight unit arranged in the backlight unit passes through the liquid crystal display element, so that an image displayed on the liquid crystal display element is visually recognized. .

  As an example of such a surface light source device, a backlight unit generally constituted by a primary light source, a light diffusion sheet, and a prism sheet is known. In such a backlight unit, the light emitted from the primary light source is diffused by the light diffusing sheet, is incident on the prism sheet, etc., and has a distribution that shows a peak in a substantially normal direction by the prism portion formed on the prism sheet surface. It is emitted as a light beam. By disposing a liquid crystal display element (display unit) on the emission surface side of the backlight unit, the liquid crystal display element can be illuminated with light emitted from the backlight unit.

  However, for example, when a fluorescent discharge tube (cold cathode tube) is used as the primary light source used in the backlight unit, ultraviolet rays are included in the light emitted from the primary light source. When ultraviolet rays are included in the light transmitted through the liquid crystal display element, the ultraviolet rays damage the liquid crystal display element. Therefore, it is necessary to remove the ultraviolet rays from the illumination light emitted from such a backlight unit.

  An example of such a surface light source device in which the generation of ultraviolet rays is suppressed has a simple structure in which an ultraviolet absorbing layer is provided on one surface of a light diffusion sheet, and many proposals have been made for a long time, and some of them have been put into practical use. (For example, refer to Patent Documents 1 and 2.)

In recent years, in such a surface light source device, light conversion is performed by directly receiving light emitted from a plurality of primary light sources, converting the traveling direction of the light to each primary light source, and converting the light toward a predetermined direction. An optical member provided with an element has been proposed (for example, see Patent Document 3). According to such an optical member, the directivity and uniformity of illumination light by the surface light source device can be improved without providing a light diffusion function.
JP-A-4-18346 (Claims) JP2003-302629A (FIGS. 1 to 6) JP 2002-352611 A

  According to the light diffusing sheet described in Patent Document 1 or 2, since light is diffused by the diffusing sheet, there is a problem that transmission efficiency is lowered. In addition, a separate prism sheet is necessary for irradiating diffused and emitted light toward the liquid crystal display element with enhanced directivity, and there is a problem that the number of members increases.

  On the other hand, the optical member described in Patent Document 3 is improved in directivity and uniformity, but does not consider the shielding of ultraviolet rays. In addition, there is a problem that a highly productive technique for precisely replicating the uneven shape on the surface is not specifically disclosed.

  Therefore, the present invention is a surface-shaped light conversion element having a concave-convex pattern on the surface for converting the light emitted from the primary light source toward a predetermined direction on the surface side to increase the directivity, An object of the present invention is to provide an optical member that transmits visible light but can substantially block ultraviolet rays, and has high productivity, a method for manufacturing the same, a surface light source device using the same, and a display device.

  In general, in order to manufacture an optical member with increased productivity, a molding process using a plastic material as a transparent material is simple. Here, as a method of replicating a fine concavo-convex pattern using a plastic material, for example, a method of manufacturing an optical disc or other optical components is well known. Such a manufacturing method uses an injection molding method, an extrusion molding method, a heat press molding method (compression method), a thermoforming method such as an injection compression molding method (injection / compression method), or a 2P method using a photocurable resin. It has been.

  Here, according to the thermoforming method, if a resin material that transmits visible light but substantially shields ultraviolet rays is used as the resin material to be used, the surface has an uneven pattern, visible light is transmitted but ultraviolet rays are not transmitted. It is possible to directly mold an optical member that can be substantially shielded.

  However, the thermoforming method generally requires a high temperature and a high pressure, so that there is a problem that an increase in size of the apparatus cannot be avoided. Further, in the case of a method for manufacturing an optical component that needs to deflect the traveling direction of light, since the uneven surface as the molding surface includes an inclined portion, a higher degree of unevenness restoration than that of the optical disk is required. Therefore, the product price was expected to be expensive.

  On the other hand, the 2P method using a photocurable resin has an advantage that it can be instantaneously cured by irradiation with ultraviolet rays and a fine uneven pattern of a mold can be faithfully reproduced. However, since the ultraviolet curable resin is a resin that is cured by irradiating ultraviolet rays, there is a problem that it is difficult to produce a practical cured body that substantially shields ultraviolet rays but transmits visible light. . Furthermore, since the obtained cured body also needs to have a certain quality as an optical component (for example, durability against ultraviolet rays and handleability), molding using only an ultraviolet curable resin is not possible. There was also a problem that the price of raw materials would rise compared to the molding method.

  In addition, in recent backlights for liquid crystal televisions and the like, the amount of light from the primary light source tends to increase due to the necessity of improving the luminance, and the ultraviolet rays contained therein increase more and the UV curable resin itself deteriorates due to the ultraviolet rays. The problem of coloring was also assumed.

  Under such circumstances, as a result of intensive studies by the present inventors, ultraviolet rays are formed between a mold for imparting a concavo-convex pattern and a transparent resin substrate having a surface shape such as a film shape, a sheet shape, or a plate shape. Apply UV light from the transparent resin base material side while interposing a curable resin, and cure the UV curable resin by integrating it with the transparent resin base material to produce an optical component. It has been found that the above problems can be solved at once.

  That is, the present invention is a surface-shaped light conversion element having a concave-convex pattern on the surface for converting the light emitted from the primary light source toward a predetermined direction on the surface side to increase the directivity, The concavo-convex pattern is shaped as a cured body of a curable resin that may be cured by ultraviolet rays, and the cured body is transparent in surface shape via an ultraviolet curable resin that may be the same as the curable resin. An optical member that is fixed to one surface of a resin base material based on ultraviolet curing, and an ultraviolet shielding layer that transmits visible light but substantially shields ultraviolet rays is provided on one surface of the light conversion element. It is.

  Here, when an ultraviolet curable resin is selected as the curable resin, a cured body that forms an uneven pattern may be directly fixed to one surface of the transparent resin substrate.

  If comprised in this way, the ultraviolet-ray shielding layer which permeate | transmits visible light but substantially shields an ultraviolet-ray will be provided in one surface of the light conversion element, and an uneven | corrugated pattern is shaped with curable resin. As a result, the concavo-convex pattern for converting the light emitted from the primary light source toward a predetermined direction on the surface side and enhancing the directivity to be emitted is faithfully reproduced, and visible light is transmitted by the ultraviolet shielding layer. Ultraviolet rays can be substantially blocked.

  In addition, since this concavo-convex pattern is fixed to one surface of the surface-shaped transparent resin base material via an ultraviolet curable resin, as a transparent resin base material, by selecting an inexpensive material with good handleability, The price of the cured product is not increased and the handleability is improved.

  Here, the ultraviolet shielding layer may be provided in any part. It is simplest to provide on the surface of the transparent resin substrate. Further, an ultraviolet shielding layer can be provided on the surface of the concavo-convex pattern.

  When such an optical component is used as a surface light source device, it is preferable to dispose a primary light source toward the ultraviolet shielding layer. In this case, the uneven pattern may be disposed on the incident surface facing the primary light source, or may be disposed on the exit surface facing the primary light source. In any case, the ultraviolet ray contained in the light emitted from the primary light source is shielded by the incident surface to the optical component by disposing the ultraviolet shielding layer toward the primary light source. It is possible to suppress degradation based on the above.

  Here, the primary light source may be any of a point light source, a surface light source, and a line light source, and there may be a plurality of primary light sources, but the uniformity and directivity of light emitted from the primary light source is improved. It is preferable that the surface has an uneven pattern that can be injected.

  Such an optical component can be suitably used for a liquid crystal display device including a direct type surface light source device.

  In the present invention, the method for producing the above optical component is not limited, but for example, it is preferably produced by the following method.

  The first optical component manufacturing method includes an intimate process in which an ultraviolet curable resin is interposed between a mold for imparting a concavo-convex pattern and a surface-shaped transparent resin substrate, and a transparent resin substrate. Visible light is transmitted through one surface of a cured body formed by passing through the curing step, a curing step in which the ultraviolet curable resin is integrated with the transparent resin substrate and cured by irradiating ultraviolet rays. The ultraviolet ray includes a shielding layer applying step for providing an ultraviolet shielding layer that substantially shields, and a demolding step for removing the cured body from the mold.

  Further, the second optical component manufacturing method includes providing a transparent curable resin containing an ultraviolet absorber to a mold for providing an uneven pattern, and curing the transparent curable resin to obtain a transparent curable resin. An uneven shielding layer applying step for forming an uneven shielding layer formed in an uneven pattern shape comprising: an intimate contact step in which an ultraviolet curable resin is interposed between the uneven shielding layer and a surface-shaped transparent resin substrate A curing step in which the ultraviolet curable resin is integrated with the transparent resin substrate and cured by irradiating ultraviolet rays through the transparent resin substrate, and a demolding step in which the cured body is removed from the mold. It is characterized by.

  In these optical component manufacturing methods, even when the mold is an opaque mold, the ultraviolet curable resin can be cured by irradiating ultraviolet rays through the transparent resin substrate. Accordingly, it is not necessary to use a transparent mold as a mold, so that the selection range of the mold is widened, and an optical component in which the concavo-convex pattern is reliably restored can be manufactured at a low cost.

  According to the present invention, a light beam conversion element having a surface shape having a concavo-convex pattern on the surface for converting the light beam emitted from the primary light source toward a predetermined direction on the surface side to enhance directivity, Visible light can be transmitted, but ultraviolet light can be substantially blocked, and an optical member with high productivity can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. In the following drawings, for the convenience of explanation, the scale of each part is illustrated by a schematic diagram that is randomly changed.

  First, FIG. 1 is a figure explaining the process of the manufacturing method of the 1st optical component as an example of the manufacturing method of this invention.

Here, the manufacturing method of a 1st optical component includes a close_contact | adherence process, a hardening process, a shielding layer provision process, and a demolding process.
[Close process]
First, the intimate step (FIG. 1a) is a step in which an ultraviolet curable resin is interposed between a mold for imparting an uneven pattern and a surface-shaped transparent resin substrate.

  In FIG. 1A, reference numeral 1 denotes a mold. A transparent resin substrate 2 is disposed on the engraving surface 1 a of the mold 1, and an ultraviolet curable resin 3 is interposed between the mold 1 and the transparent resin substrate 2 in close contact.

  Here, the mold 1 may be transparent or opaque. The surface is provided with an engraving surface 1a for giving a predetermined uneven pattern to the molded product.

  Here, the predetermined concavo-convex pattern is a concavo-convex pattern for converting a light beam emitted from the primary light source toward a predetermined direction on the surface side to emit with enhanced directivity. The uneven pattern is appropriately selected depending on the type and position of the primary light source.

  Such a concavo-convex pattern is formed by arranging convex (protruding) portions having a projecting cross section and / or concave (groove) portions having a concave cross section in one direction or a planar direction. The cross-sectional shape of these convex portions or concave portions may be a desired shape such as a triangular shape, a wedge shape, a trapezoidal shape, another polygonal shape, a wave shape, or a semi-elliptical shape. These convex portions or concave portions are generally arranged at a pitch within a range of 10 μm to 1000 μm, preferably within a range of 20 μm to 500 μm, and particularly within a range of 30 to 300 μm.

  Such a mold 1 is provided with a sculpture surface 1a in which irregularities are engraved on a flat plate or roll of metal, for example. In order to replicate a delicate uneven pattern, the mold is generally made of an opaque material such as metal. However, the mold material is not limited as long as a desired uneven pattern can be formed. For example, a resin mold may be used which may be transparent. Further, an appropriate releasability may be imparted to the engraving surface 1a of these molds, or a release agent may be imparted as necessary.

  Next, the transparent resin base material 2 will not be restrict | limited especially if it is a base material transparent with respect to the light ray from an ultraviolet-ray to visible light. Such a transparent resin base material 2 forms part of the optical component of the present invention, and in addition to being sufficiently optically transparent, it has adhesiveness (adherence to an ultraviolet curable resin described later). It is necessary that the property is good. Moreover, it is preferable that the obtained optical component is a material with good assembly workability and durability, and it is preferable to select a relatively inexpensive material in consideration of the cost of the product. An example of such a transparent resin substrate 2 is a methacrylic resin such as a methacrylic resin, an acrylic resin, a methacryl-styrene copolymer (MS) resin, or a polycarbonate resin. If a material having good adhesion to the ultraviolet curable resin can be selected, for example, other transparent resin substrates such as a polyester resin, a cyclic polyolefin resin, and a polystyrene resin may be used. Such a transparent resin substrate 2 is a planar substrate (planar substrate) such as a film, sheet, or plate, and these planar substrates are wound up by a winding roll or the like. It may be supplied in the form of a long object.

  The ultraviolet curable resin 3 is selected in consideration of adhesiveness (adhesiveness) with the transparent resin substrate 2 and durability as a cured body. Here, the adhesiveness (adhesiveness) means that when the ultraviolet curable resin is cured in a state where the transparent resin substrate 2 and the ultraviolet curable resin 3 are in close contact with each other, the cured body and the transparent resin substrate 2 are separated. It means to fix with practical strength without.

  There are various types of such ultraviolet curable resins, oligomers having one or more functional groups in the molecule that can react to form a crosslinked structure by reacting with ultraviolet irradiation, and one or more similar functional groups in the molecule. Having monomers or both are used. As the oligomer or monomer, those forming radical polymerization curable resins such as unsaturated polyester resins, acrylic resins, ene / thiol resins, or cationic polymerization curable resins such as epoxy resins are formed. Things. Among them, those having an acryloyl group in the molecule are generally used, and epoxy acrylate type, urethane acrylate type, polyester acrylate type, polyol acrylate type oligomers or polymers, and monofunctional, bifunctional or polyfunctional acrylics. Mixtures with system monomers are preferably used.

  Moreover, you may mix | blend various polymerization initiators as needed, and as a polymerization initiator, 2,2-dimethoxy-2-phenylacetone, acetophenone, benzophenone, xanthofluorenone, benzaldehyde, anthraquinone, 1- (4 -Isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4-oxanthone, camphorquinone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, etc. Can be mentioned.

  In the present invention, an ultraviolet curable resin 3 is closely interposed between the mold 1 and the transparent resin substrate 2. Here, the close contact means that the ultraviolet curable resin 3 filled or supplied in the mold is brought into close contact with the engraving surface 1a so that the shape of the engraving surface can be faithfully reproduced. That is, the close contact in the present invention is not necessarily required to be brought into pressure contact with the high pressure, and the resin material may be applied uniformly between the engraving surface 1a of the mold 1 and the transparent resin base material 2.

Moreover, the supply method of the ultraviolet curable resin 3 can also be selected suitably. For example, the ultraviolet curable resin 3 may be supplied directly to the engraving surface 1a, or after the ultraviolet curable resin 3 is supplied to the transparent resin substrate 2 side, the ultraviolet curable resin 3 is directly applied to the engraved surface 1a. May be supplied. Further, an ultraviolet curable resin may be supplied between the engraving surface 1 a and the transparent resin substrate 2. In any supply method, the close contact with the mold 1 and the transparent resin substrate 2 with the ultraviolet curable resin 3 interposed therebetween can suppress the generation of bubbles at each interface.
[Curing process]
Next, as shown in FIG. 1B, the curing process is a process in which the ultraviolet curable resin 3 is integrated with the transparent resin substrate 2 and cured by irradiating the ultraviolet ray UV through the transparent resin substrate 2. is there. Thereby, the transparent resin base material 2 and the cured body 3 are fixed and integrated, and a fine uneven pattern corresponding to the shape of the engraving surface 1a is duplicated on the surface (cured surface) 3a.
[Shielding layer application step]
Next, as shown in FIG. 1C, in the shielding layer applying step, visible light is transmitted through the surface (smooth surface) of the transparent resin substrate 2 of the cured body 3 shaped by passing through the curing step. Is a step of providing an ultraviolet shielding layer 4 that substantially shields ultraviolet rays.

  In order to provide the shielding layer 4, for example, it is easy to laminate an ultraviolet absorbing film, and if the ultraviolet absorbing film is a heat-fusible film, it can be easily laminated because it can be laminated by heat. Such a heat-sealable UV-absorbing film can be prepared, for example, by introducing an appropriate UV-absorbing agent into a transparent commercially available film that can be heat-sealable.

Moreover, this shielding layer 4 can also be provided by the apply | coating method which provides the transparent resin which has an ultraviolet absorptivity to the surface. Such a resin composition may be a curable resin composition that can be polymerized or crosslinked by heat or chemical reaction to form a cured surface. In any case, the cured body must have a property of blocking visible light but transmitting visible light.
[Demolding process]
As shown in FIG. 1 (d), the demolding step is a step of peeling and demolding a surface-shaped molded product such as a plate, film, or sheet from the mold 1. By removing from the mold 1, a fine uneven pattern corresponding to the shape of the engraving surface 1 a is faithfully reproduced on the cured surface 3 a. Thereby, the molded product (optical component) 10 as the target hardening body can be obtained. This molded product 10 is supplied as an optical component 10 as it is.

  When the transparent resin base material 2 is a long or large-area film or sheet shape, and a concavo-convex pattern is formed on the surface thereof, it is cut into a desired size as necessary, and one optical component and You can also

  The obtained optical component 10 has a transparent resin base material 2 as a base material, and a cured body 3 of an ultraviolet curable resin is fixed to one surface of the transparent resin base material 2 and visible light is transmitted to the other surface. An ultraviolet shielding layer 4 that substantially shields ultraviolet rays is provided. In addition, a predetermined uneven pattern corresponding to the uneven pattern of the engraving surface 1 a is formed on the surface 3 a of the cured body 3.

  When such an optical component is used as a direct-type surface light source device, the surface 4a of the smooth ultraviolet shielding layer 4 formed on the transparent resin substrate 2 is used as the incident surface of the primary light source, and UV curable. It is preferable to use the surface 3a having a concavo-convex pattern made of resin as the injection surface.

  Next, FIG. 2 is a figure explaining the process of the manufacturing method of the 2nd optical component as another example of the manufacturing method of this invention.

Moreover, the manufacturing method of a 2nd optical component includes an uneven | corrugated shielding layer provision process, an intimate process, a hardening process, and a demolding process. Hereinafter, each step will be described in order, but the same or equivalent part members as in FIG. 1 are assigned the same numbers, and detailed description may be omitted.
[Uneven layer application step]
As shown in FIG. 2 (a), the uneven layer applying step applies a transparent curable resin containing an ultraviolet absorber to a mold for applying an uneven pattern, and cures the transparent curable resin. This is a step of forming a shielding layer.

  In FIG. 2A, reference numeral 1 denotes a mold having an engraving surface 1a, which is the same as or equivalent to the mold 1 shown in FIG.

A curable resin that can be polymerized by heat, chemical reaction, or the like on the engraving surface 1a of the mold 1 to form a cured surface, and is a curable resin that substantially absorbs ultraviolet rays but transmits visible light. Apply a thin layer. Next, the curable resin is cured by heat or chemical reaction to form the uneven shielding layer (cured body) 4 '. Thereby, the engraving surface 1a is transferred to the surface 4′a of the uneven shielding layer 4 ′ formed by the cured body of the curable resin.
[Close process]
As shown in FIG. 2 (b), the close contact process is a process in which an ultraviolet curable resin 3 is interposed between the uneven shielding layer 4 'and the planar transparent resin base material 2 to make close contact. The transparent resin base material 2 is disposed on the concave / convex shielding layer 4 ′, and an ultraviolet ray that is the same or equivalent to that used in the first manufacturing method between the concave / convex shielding layer 4 ′ and the transparent resin base material 2. The curable resin 3 is intimately interposed.

Here, the close contact means that the ultraviolet curable resin 3 filled or supplied in the mold and the transparent resin base material 2 are brought into close contact with each other, and generation of voids at the interface can be suppressed to cure the ultraviolet curable resin 3. Means. The UV curable resin 3 may be supplied directly to the surface 4a ′, or after the UV curable resin 3 is supplied to the transparent resin substrate 2 side, the UV curable resin 3 is applied to the surface 4a ′. You may supply. Further, an ultraviolet curable resin may be supplied between the surface 4 a ′ and the transparent resin substrate 2. In any of the supply methods, by bringing the ultraviolet curable resin 3 between the mold 1 and the transparent resin substrate 2 so as to be in close contact with each other, generation of voids at each interface can be suppressed. .
[Curing process]
As shown in FIG. 2 (c), the curing step is a step of irradiating ultraviolet rays through the transparent resin substrate 2 to cure the ultraviolet curable resin 3 together with the transparent resin substrate, This is substantially equivalent to the curing step of FIG. Thereby, by irradiating ultraviolet rays through the transparent resin substrate 2, the ultraviolet curable resin 3 is cured, and the transparent resin substrate 2 and the cured body 3 are fixed and integrated. On the surface of the cured body 3, an uneven shielding layer 4 ′ in which fine unevenness is replicated is fixed.
[Demolding process]
As shown in FIG. 2 (d), the desired molded product can be obtained by peeling the molded product 10 from the mold 1. This molded product is cut into a desired size as needed and supplied as the optical component 10.

  The obtained optical component 10 is cured by heat or a chemical reaction on the concavo-convex surface of the transparent resin base material 2 through the cured body 3 of the ultraviolet curable resin on the one surface of the transparent resin base material 2. A concavo-convex shielding layer 4 'containing an ultraviolet absorber is formed.

  When such an optical component is used as a direct-type surface light source device, the surface 2a of the smooth transparent resin substrate 2 is emitted using the uneven surface on which the uneven shielding layer 4 'is formed as the incident surface of the primary light source. It is good to be a surface.

  Next, an example of a modification of the first optical component manufacturing method will be described with reference to FIG. This modification is the same or equivalent to the manufacturing process shown in FIG. 1 except that the shielding layer 4 is provided after the demolding process.

First, as shown in FIGS. 3A and 3B, the intimate process and the curing process are sequentially performed as in the example of FIG.
[Demolding process]
Next, as shown in FIG. 3C, a demolding step is performed prior to application of the shielding layer 4. By removing from the mold 1, a fine uneven pattern corresponding to the shape of the engraving surface 1a is faithfully reproduced on the cured surface 3a.
[Shielding layer application step]
In the shielding layer applying step, as shown in FIG. 3D, visible light is transmitted through the cured surface 3a of the cured body 3 formed by the demolding step, but ultraviolet rays are substantially shielded. This is a step of applying the layer 4.

  A transparent resin composition containing an ultraviolet absorber is applied to the cured surface 3a by an application means such as a spray method. From the viewpoint of uniform film thickness, it is preferable to add a leveling agent such as fluorine, silicone, ether or ester. When the shielding layer 4 is applied to the uneven surface, it is preferable to control the shielding layer 4 to such a thickness that the shape of the uneven surface can be maintained. By blending such a leveling agent, the finished appearance of the coating film is improved, and it can be uniformly applied as a thin film.

  In the obtained optical component 10, a cured body 3 of an ultraviolet curable resin is fixed to one surface of the transparent resin substrate 2, and a concavo-convex pattern corresponding to the concavo-convex pattern of the engraving surface 1 a is formed on the surface 3 a of the cured body 3. ing. The surface 3a is provided with a thin layer of an ultraviolet shielding layer 4 that transmits visible light but substantially shields ultraviolet rays. A predetermined uneven pattern is formed on the surface of the ultraviolet shielding layer 4.

  When such an optical component 10 is used as a direct-type surface light source device, the surface 2a of the transparent transparent resin substrate 2 is emitted with the uneven surface on which the ultraviolet shielding layer 4 is formed as the incident surface of the primary light source. It is good to be a surface.

  Next, an application example of the optical component 10 thus obtained to a surface light source device will be described.

  FIG. 4 is an example in which the optical component 10 obtained by the process of FIG. 1 is used as a direct type surface light source device. In this example, the surface light source device 12 is configured by disposing the ultraviolet shielding layer 4 toward the primary light source 11. Here, in this example, an example of the concavo-convex pattern is disclosed as an example of the concavo-convex pattern applied when a plurality of line light sources are used, and the detailed configuration thereof is described in detail in, for example, Patent Document 3. As a result, each light beam a emitted from the linear light source 11 such as a fluorescent tube as each primary light source is emitted from the surface 3a of the cured body 3 as a light beam b. At that time, the light beam b is converted toward a certain direction (predetermined direction) on the surface side, and directivity and uniformity are improved.

  Next, an application example of the surface light source device 12 thus obtained to a liquid crystal display device as an example of a display device will be described.

  If the liquid crystal display element 13 is disposed facing the surface 3a of the surface light source device 12, a liquid crystal display device 14 as shown in FIG. 5 is formed. According to the liquid crystal display device 14 as described above, light rays a (not shown) divergently emitted from the plurality of line light sources 11... Improve directivity and uniformity from the surface 3 a toward the liquid crystal display element 13. It is emitted (ray b). The light beam b illuminates the liquid crystal display element 13 and is emitted from the liquid crystal display element 13 as a light beam c, so that a high-luminance image can be displayed by the action of the liquid crystal display element 13.

  Even when the primary light source 11 includes ultraviolet rays, the ultraviolet rays are shielded by the ultraviolet shielding layer 4 disposed on the primary light source 11 side of the optical member 10, so that they do not pass through the optical component 10, and the liquid crystal The display element 13 is not substantially irradiated with ultraviolet rays.

Examples The effects of the present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.
Example 1
An acrylic resin (trade name: Paragrass UV00) with a thickness of 2 mm that does not contain an ultraviolet absorber is used as the transparent resin substrate.

  A lenticular concavo-convex mold was cut in advance into a flat Cu mold to form an engraved surface. The pitch of the lenticular shape of this engraving surface is 260 μm, and the depth (height) is 182 μm.

  A predetermined amount of urethane acrylate UV curable resin is applied to the engraving surface. The amount of this coating is not particularly limited, but when a sufficient amount is filled with respect to the engraving surface, and the surface of the applied UV curable resin becomes a smooth surface and the transparent resin substrate is brought into close contact with the void, An amount that does not occur is necessary.

Next, the transparent resin base material was stacked and pressed from above, and after adjusting the thickness according to the optical design, ultraviolet rays of 10 mW / cm ² were irradiated for 5 minutes using a high pressure mercury lamp to cure the ultraviolet resin.

  Next, a flexible ultraviolet absorbing film containing an ultraviolet absorber was thermally laminated on the exposed surface of the transparent resin substrate to integrate the transparent resin substrate and the ultraviolet absorbing film. Thereafter, the molded product was peeled off from the mold to obtain a plate-shaped molded product having an uneven surface and transparent to visible light.

This plate-like molded article is a molded article (optical component) having an uneven surface that has a transmittance of 50% or less at a wavelength of 370 nm or less and does not substantially transmit ultraviolet rays.
(Example 2)
On the surface side of the exposed transparent resin substrate, a predetermined amount of a transparent epoxy resin containing UV absorber (trade name: manufactured by SYSTEM THREE, SB-112) is applied instead of the UV absorbing film of Example 1, and natural Cured. Here, the predetermined amount is such that the ultraviolet shielding rate of the obtained molded product becomes a desired value.

Subsequently, the molded product was peeled from the mold to obtain a transparent plate-shaped molded product having an uneven surface. This plate-shaped molded article is a molded article (optical component) having an uneven surface that has a transmittance of 50% or less at a wavelength of 370 nm or less and does not substantially transmit ultraviolet rays.
(Example 3)
The same mold as that used in Example 1 was used, and the engraved surface of the mold was easily peeled with a fluorine-based resin in advance.

  Next, the UV-absorbing curable resin (composition in which a UV absorber was kneaded with a transparent epoxy resin) used in Example 2 was applied and naturally cured to form an uneven shielding layer 4 'on the engraving surface.

  Thereafter, the same ultraviolet curable resin as used in Example 1 was applied to the surface of the uneven shielding layer 4 ′, and the transparent resin substrate was stacked and closely adjusted in the same manner as in Example 1, Ultraviolet rays were irradiated using a high-pressure mercury lamp.

By peeling the molded product from the mold, a transparent plate-shaped molded product having an uneven surface was obtained. This transparent molded article is a molded article (optical component) having a concavo-convex surface that has a transmittance of 50% or less at a wavelength of 370 nm or less and does not substantially transmit ultraviolet rays.
(Comparative Example 1)
In Example 1, it was set as the transparent plate-shaped molded article which has an uneven surface without laminating | stacking a flexible film. This molded article had a high transmittance at a wavelength of 370 nm or less and did not have an ultraviolet shielding performance.
(Comparative Example 2)
Using an acrylic resin plate (trade name: Comoglass DK-3) containing an ultraviolet absorber in advance as a transparent resin base material, the mold was filled with an ultraviolet curable resin in the same manner as in Example 1, and the transparent resin base material was Again, ultraviolet rays were irradiated from the transparent resin substrate side. The ultraviolet curable resin did not harden sufficiently, and the shape of the mold could not be transferred to the ultraviolet curable resin.
(Comparative Example 3)
The mold was filled with an ultraviolet curable resin containing an ultraviolet absorber, the transparent resin base material was stacked and brought into close contact with each other, and ultraviolet rays were irradiated through the transparent resin substrate in the same manner as in Example 1. The ultraviolet curable resin was sufficient and did not harden, and did not adhere to the transparent resin substrate. Ultraviolet rays were irradiated for a longer time by increasing the irradiation time of the ultraviolet rays. Similarly, the ultraviolet curable resin was not sufficiently cured and the shape of the mold could not be transferred.

  Although the embodiment of the present invention has been described above, the specific configuration is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention.

  For example, only the line light source such as a fluorescent tube is illustrated and described as the primary light source when the optical component according to the present invention is used as the surface light source device. However, the primary light source is not limited to the line light source but is a point light source. Alternatively, it may be a linear light source in which a large number of point light sources such as LED light sources are arranged to form a linear shape.

  In addition, although the shape of the mold is not described in detail, for example, a square in plan view, a roll shape (roll type), and other shapes may be arbitrary.

  In the case of a roll type, a predetermined concavo-convex pattern may be cut by cutting or the like on the surface of the roll by a conventional method to form the engraving surface 1a. By selecting and using a flexible material as the transparent resin base material, it is possible to make it intimately contact with each other via an ultraviolet curable resin supplied between the engraving surface 1a and the flexible transparent resin base material.

  In addition, in the optical component 10 obtained by the process of FIG. 2 or FIG. 3, since the ultraviolet shielding layer is provided on the uneven surface, it is preferable to dispose a primary light source toward the ultraviolet shielding layer.

  The optical component described above is a surface-shaped light conversion element having a concavo-convex pattern on the surface for converting the light emitted from the primary light source toward a predetermined direction on the surface side to increase directivity and emitting the light. Visible light is transmitted, but ultraviolet rays can be substantially blocked. In addition, since the optical component having such a configuration has high productivity, it is not limited to a surface light source device such as a backlight unit of a liquid crystal display device, but can be applied to various display devices such as a monitor device, a lighting announcement, and a traffic sign. Application is expected.

It is a figure explaining the manufacturing process of the optical component which concerns on this invention. It is a figure explaining the manufacturing process of the optical component which concerns on this invention. It is a figure explaining the manufacturing process of the optical component which concerns on this invention. It is a schematic diagram which shows an example of the surface light source device which concerns on this invention. It is a schematic diagram which shows an example of the liquid crystal display device which concerns on this invention.

Explanation of symbols

1: Mold 1a: Engraving surface 2: Transparent resin substrate 2a: Surface 3: UV curable resin (cured body)
3a: Surface 4: UV shielding layer (shielding layer)
4a: Surface 4 ': Concavity and convexity shielding layer (cured body)
4a ': Surface 10: Optical component (molded product)
11: Primary light source 12: Surface light source device (backlight unit)
13: Liquid crystal display element 14: Liquid crystal display device (display device)

Claims (8)

A light beam conversion element having a surface shape having a concavo-convex pattern on the surface for converting the light beam emitted from the primary light source toward a predetermined direction on the surface side to increase directivity,
The concavo-convex pattern is shaped as a cured body of a curable resin that may be cured with ultraviolet rays,
The cured body is fixed to one surface of a transparent resin substrate having a surface shape through an ultraviolet curable resin which may be the same as the curable resin, based on ultraviolet curing,
An optical member, characterized in that an ultraviolet shielding layer that transmits visible light but substantially shields ultraviolet rays is provided on one surface of the light conversion element. The uneven pattern is shaped as a cured body of an ultraviolet curable resin that is fixed to one surface of the transparent resin substrate,
The optical component according to claim 1, wherein the ultraviolet shielding layer is provided on a surface of a transparent resin base material. The optical component according to claim 1, wherein the ultraviolet shielding layer is provided on a surface of the concavo-convex pattern. A surface light source device using the optical component according to claim 1, wherein the primary light source is disposed toward the ultraviolet shielding layer. A display device comprising the direct type surface light source device according to claim 4. It is a manufacturing method of the optical component according to claim 1 or 2,
A close process in which an ultraviolet curable resin is interposed between a mold for imparting a concavo-convex pattern and a surface-shaped transparent resin substrate,
A curing step of irradiating ultraviolet rays through the transparent resin base material to cure the ultraviolet curable resin integrally with the transparent resin base material;
A shielding layer applying step of providing an ultraviolet shielding layer that transmits visible light to one surface of the cured body shaped by passing through the curing step but substantially shields ultraviolet rays;
The manufacturing method of the optical component characterized by including the demolding process which demolds a hardening body from a metal mold | die. It is a manufacturing method of the optical component according to claim 1 or 3,
A concavo-convex shielding layer formed in a concavo-convex pattern shape comprising a transparent curable resin by applying a transparent curable resin containing an ultraviolet absorber to a mold for imparting a concavo-convex pattern, and curing the transparent curable resin. An irregularity layer applying step for forming
An intimate process in which an ultraviolet curable resin is interposed between the uneven shielding layer and the surface-shaped transparent resin substrate,
A curing step of irradiating ultraviolet rays through the transparent resin base material to cure the ultraviolet curable resin integrally with the transparent resin base material;
Demolding process to demold the cured body from the mold,
The manufacturing method of the optical component characterized by including. 8. The method of manufacturing an optical component according to claim 6, wherein the mold is an opaque mold.

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