JP2013068771A - Method for manufacturing curved screen for back transmission type display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a curved screen for a back transmission type display, free from a crack in a hard coat layer, avoiding inclusion of a foreign substance, and with excellent productivity.SOLUTION: A manufacturing method is for a curved screen 100 for a back transmission type display comprising a laminate having a three-dimensional curved surface for transmitting video light from a light incident surface side to a light emitting surface side. The manufacturing method comprises: a laminate preparation step for preparing a tabular laminate 10 with a lamination of a transfer foil 20 in which a curable resin has a semi-cured hard coat layer 21A formed on a detachable support medium 22; and a first curved surface formation step for bending the laminate to obtain a three-dimensional curved surface. The method further comprises: a cure progressing step following the first curved surface formation step for progressing the cure of the hard coat layer; and a support medium separation step following the cure progressing step for separating the detachable support medium. The laminate may be laminated with an optical control layer 30 in which a light absorption part and an optical transmission part are alternately arranged, and a fresnel lens sheet 40.

Description

  The present invention relates to a method of manufacturing a curved screen for a back transmissive display having a curved shape that transmits image light projected from the back side to the front side.

With the widespread use of display devices, display devices are being incorporated into various fields. For example, it is not limited to televisions and their projectors, but is in the fields of amusement equipment and automobiles. In these fields, design features that are in harmony with the whole are very important, in addition to the function of simply capturing images. For this reason, the display surface of the display may be required to have a curved surface instead of a flat surface.
Therefore, for example, Patent Document 1 proposes a liquid crystal display panel with a curved display surface itself.

JP 2009-63701 A

However, as disclosed in Patent Document 1, when the liquid crystal display panel itself is curved, the liquid crystal display panel usually includes a pair of glass substrates, so that the glass substrate is 0.7 mm, 0.5 mm, or the like. Although it is thin, there is a limit to the degree of curved surface.
Also, in the amusement machine and automobile fields, since a human may touch the screen directly, a hard coat layer is necessary as a surface layer in order to prevent the surface from being scratched.

As the resin for the hard coat layer, using an ionizing radiation curable resin rather than a thermosetting resin is superior in terms of preventing scratches on the surface. However, when a laminated body provided with a hard coat layer is bent using a molding die, the yield decreases if a foreign matter such as dust is caught. Therefore, in order to increase the yield, the hard coat layer of the ionizing radiation curable resin is too hard and the foreign matter removing operation is not easy. In this respect, as the resin of the hard coat layer, the thermosetting resin is more applicable than the ionizing radiation curable resin, but the problem of the surface scratch resistance being inferior compared to the ionizing radiation curable resin. There is.
In addition, if a flat screen that is spray-coated with a hard coating using an ionizing radiation curable resin that is excellent in preventing scratches on the surface as a hard coat layer is formed into a curved surface, minute cracks will occur in the hard coat layer, resulting in improved quality. A problem has been found that may reduce. On the other hand, if the hard coat layer is spray-coated after a flat screen is formed into a curved surface, the crack is eliminated.
However, in any case, spray coating has a problem that dust easily adheres and drying time is required, resulting in poor productivity.

  That is, the subject of this invention is providing the manufacturing method which can manufacture with sufficient productivity, even when a hard-coat layer is provided as a curved screen for backside transmissive displays. In addition, even when a hard coat layer is provided as a curved screen for a rear transmission type display, a manufacturing method that can be manufactured with high productivity without causing cracks in the hard coat layer and preventing biting of foreign matters is provided. is there.

The manufacturing method of the curved screen for backside transmissive displays according to the present invention has the following configuration.
(1) A method of manufacturing a curved screen for a rear transmissive display, comprising a laminate that has a curved surface shape by transmitting image light incident from the light incident surface side to the light exit surface side,
As the laminate, a laminate prepared by preparing a laminate in which a transfer foil is laminated and the transfer foil is a transfer foil having a hard coat layer formed on a peelable support. Process,
Including a first curved surface forming step of forming and bending the flat laminate prepared in the laminated body preparation step so as to form a three-dimensional curved surface,
The ionizing radiation curable resin constituting the hard coat layer in the laminate preparation step is in a semi-cured state,
After the first curved surface forming step, the curing progressing step of advancing the curing of the ionizing radiation curable resin of the hard coat layer,
After the curing progressing step, the peelable support of the transfer foil is peeled off, a support peeling step,
A method of manufacturing a curved screen for a rear transmission type display.

(2) A light control layer in which the laminate includes a light absorbing portion arranged along a layer surface so as to be able to absorb light, and a light transmitting portion arranged so as to be able to transmit light between the light absorbing portions. A manufacturing method of the curved screen for back transmission type display of the above (1) including.
(3) The method for producing a curved surface screen for a rear transmission type display according to (1) or (2), wherein the laminate includes a Fresnel lens layer on the most light incident surface side of the laminate.

(4) preparing a Fresnel lens sheet having a Fresnel lens layer, a Fresnel lens sheet preparation step;
A second curved surface molding step of forming and bending the Fresnel lens sheet to form a three-dimensional curved surface;
The light-incident surface side of the laminate that has been bent so as to form a three-dimensional curved surface in the first curved surface forming step, and that is bent so as to form a three-dimensional curved surface, prepared in the second curved surface forming step. A laminating step of laminating a Fresnel lens sheet;
Including
Before or after the laminating step, including a step of curing the hard coat layer,
(1) The manufacturing method of the curved screen for back transmissive displays of (1) or (2).

  According to the present invention, when the curved surface is formed, the hard coat layer is formed not from painting but from the transfer foil, so that it is excellent in productivity and can prevent dust from being caught. Moreover, at the time of curved surface molding, the hard coat layer is cured at a stage before the resin is cured in a semi-cured state and becomes a high-quality coating film, and the remaining curing is advanced after the curved surface molding. Prevents cracks in the coating layer.

Explanatory drawing explaining 1st Embodiment of the manufacturing method of the curved screen for back surface transmission type displays by this invention. Sectional drawing (A) which shows the layer structure of the laminated body prepared at a laminated body preparation process, and sectional drawing (B) which shows the curved screen for back surface transmission type displays manufactured. Sectional drawing which shows another layer structure of the laminated body prepared at a laminated body preparation process. Sectional drawing explaining a shaping | molding method. Explanatory drawing explaining 2nd Embodiment of the manufacturing method of the curved screen for back surface transmission type displays by this invention. Sectional drawing which shows the layer structure of the laminated body prepared by a laminated body preparation process in 2nd Embodiment. Sectional drawing which shows the layer structure of the curved screen for back surface transmissive displays obtained in 2nd Embodiment.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are conceptual diagrams, and the scale relationships, aspect ratios, and the like of components may be exaggerated.

<< A >> 1st Embodiment First, with reference to FIG. 1, 1st Embodiment of the manufacturing method of the curved screen for back surface transmission type displays of this invention is described.
In this embodiment, image light incident from the light incident surface side is transmitted to the light output surface side to form a curved surface shape, and the light output surface side is a convex curved surface toward the outside. To manufacture a curved screen for rear transmissive display.
Therefore, in the present embodiment, a flat laminate having a hard coat layer, a light diffusion layer, a light control layer, a Fresnel lens layer, and the like as a transfer foil is formed into a three-dimensional curved surface to be used for a rear transmission type display. A curved screen is manufactured.

  Hereinafter, it demonstrates from a laminated body preparation process in order of a process.

<< Laminated body preparation process >>
As shown in FIG. 1 (A), in the laminate preparation step, a flat laminate 10 in which a transfer foil 20 is laminated as a flat laminate 10 having a hard coat layer, the transfer foil 20. A laminate 10 is prepared which is a transfer foil 20 in which a semi-cured hard coat layer 21 </ b> A made of a semi-cured ionizing radiation curable resin is formed on a peelable support 22.
In addition to this, the laminated body 10 of the present embodiment shown in FIG. 1A is further laminated with a light diffusion layer 11, a light beam control layer 30, a Fresnel lens sheet 40, and the like.

  The cross-sectional view of FIG. 2 shows details of the layer configuration of the laminate 10 prepared in the present embodiment. The laminated body 10 has a configuration in which a transfer foil 20, a light diffusion layer 11, an optical control layer 30, a reinforcing layer 14, and a Fresnel lens sheet 40 are laminated in order from the light exit surface side Lout with a bonding layer 13 therebetween. is there. The Fresnel lens layer 41 included in the Fresnel lens sheet 40 is the outermost layer and is the light incident surface side Lin.

  Hereinafter, each layer of the laminate 10 will be further described.

[Transfer foil 20]
The transfer foil 20 includes at least a semi-cured hard coat layer 21A as a hard coat layer and a peelable support 22 on which the semi-cured hard coat layer 21A is laminated. The main resin constituting the semi-cured hard coat layer 21A is an ionizing radiation curable resin.

[Semi-cured hard coat layer 21A or hard coat layer 21]
The semi-cured hard coat layer 21A becomes the hard coat layer 21 after the curing proceeds, and becomes a surface layer on the light-emitting surface side Lout of the curved screen 100 for rear transmission type display as shown in FIG. It is a layer that prevents scratches on the surface.
In the present invention, “hard coat” means that a hardness of “HB” or higher is shown in a pencil hardness test specified by JISK5600-5-4 (1994).
The thickness of the semi-cured hard coat layer 21A or the hard coat layer 21 depends on the application and required specifications, but can be, for example, about 5 to 50 μm.

  The semi-cured hard coat layer 21 </ b> A becomes a hard coat layer 21 which is finally fully cured by curing of the resin in a subsequent curing progress step. The hard coat layer 21 constitutes an image display surface of the curved surface screen 100 for rear transmissive display. For this reason, the hard coat layer 21 is made of a transparent curable resin in order to provide scratch resistance against scratches due to contact with other objects and to provide more excellent scratch resistance. Is done. As the curable resin, an ionizing radiation curable resin, which is superior to thermosetting resins such as urethane resins, is used as a main resin. The ionizing radiation curable resin is a resin that is cured by ionizing radiation such as ultraviolet rays and electron beams, and is also called a photocurable resin.

Various types of ionizing radiation curable resins may be used. For example, urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, acrylic acrylate and other acrylate-based prepolymers, polyfunctional acrylate-based monomers, vinyl-based resins. A resin composition comprising one or more polymerizable compounds such as monomers can be used.
This resin composition contains a photopolymerization initiator when these polymerizable compounds are further cured with ultraviolet rays. The resin composition may contain various known additives such as thermoplastic resins such as acrylic resins and polyester resins, and other stabilizers.

In the semi-curing of the ionizing radiation curable resin, it is preferable to keep the curing reaction in a semi-cured state by suppressing the irradiation dose of the ionizing radiation irradiated for curing the ionizing radiation curable resin to an amount that is not completely cured. Semi-curing is not limited to a state where the curing has progressed by 50%, but is a state where the surface of the semi-cured hard coat layer 21A is not less than the degree of curing that is tack-free (touch-dried state) and the curing remains. Means.
In order to achieve a more stable semi-cured state, it is preferable to use a resin composition having two types of curing mechanisms as the curing mechanism of the curing component in the ionizing radiation curable resin. Specifically, for example, there is a combination of a curing mechanism by ionizing radiation using a radical polymerization reaction and a curing mechanism by heat using an addition polymerization reaction of isocyanate.
Such an ionizing radiation curable resin is a resin composition having a radical polymerization reaction component and an addition polymerization reaction component. For example, the above-described polymerizable compound is used as the radical polymerization reaction component, and the addition polymerization reaction component is polyisocyanate, or an isocyanate group-containing radical polymerizable compound obtained by addition polymerization of polyisocyanate and the polymerizable compound, or Use both.
Examples of the polyisocyanate include tolylene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, and trimers thereof.
Also, as a reaction component for addition polymerization reaction with polyisocyanate, a compound having an isocyanate active group such as hydroxyl group or carboxyl group, for example, a polyol compound such as acrylic polyol or polyester polyol, or an acrylate compound such as acrylic acrylate or urethane acrylate , Etc. can be used in combination.

When the resin composition having the two types of curing mechanisms is used, the semi-curing can be performed with either one of the curing mechanisms, thereby achieving stable semi-curing. It is arbitrary which curing mechanism is used for semi-curing, but it is performed with an addition polymerization reaction component that can be thermally polymerized, and the radical polymerization reaction component is cured in a post-curing progressing step. This is preferable in that the cured state is more stable than leaving the components.
In this embodiment, it is semi-cured by this addition polymerization reaction of isocyanate, and is cured by radical polymerization reaction after molding into a curved surface.

[Peelable support 22]
A thermoplastic resin film (or sheet) is used as the peelable support 22. Examples thereof include polyester resins such as polyethylene terephthalate and polyolefin resins such as polypropylene. When the peelable support 22 is peeled off after the semi-cured hard coat layer 21A side has been hardened to a hard coat layer 21 that has been cured, the releasable support 22 is hard coated. In the case where it is difficult to easily peel off from the layer 21, it is preferable to perform a mold release treatment on the surface of the semi-cured hard coat layer 21A. The mold release treatment forms a coating film of melamine resin, silicone resin, alkyd resin or the like.

[Create transfer foil]
After the transfer foil 20 is applied on the peelable support 22 by a coating machine, a semi-cured hard coat layer 21A, and in the present embodiment, the bonding layer 13 is sequentially applied by a coating method such as roll coating. By heating and drying the coating film, it can be easily produced with good productivity and without adhesion of dust. At this time, simultaneously with the heat drying, as the semi-cured hard coat layer 21A, the curing of the heat-polymerizable addition polymerization reaction component in the ionizing radiation curable resin in the layer is promoted to facilitate the semi-cured state. Can do.

[Adhesion of transfer foil]
The transfer foil 20 is bonded to the light diffusion layer 11 via the bonding layer 13. The transfer foil 20 is bonded by pressing the transfer foil 20 against the surface of the light diffusing layer 11 with a transfer roller and bonding with the adhesive force of the bonding layer 13. The bonding layer 13 will be described next.
However, in the present invention, in order to adhere and laminate the semi-cured hard coat layer 21A as the transfer foil 20 to the light diffusion layer 11, the semi-cured hard coat layer 21A itself is thermally fused to exhibit adhesiveness by heating. When it has adhesiveness, the joining layer 13 can be omitted.

[Junction layer 13]
The bonding layer 13 is a layer for bonding the layers on both sides thereof. The bonding layer 13 is provided according to the necessity of the bonding layer 13.
In the present embodiment, the bonding layer 13 is formed by bonding the semi-cured hard coat layer 21 </ b> A and the light diffusion layer 11, bonding the light diffusion layer 11 and the optical control layer 30, and bonding the optical control layer 30 and the reinforcing layer 14. It is used for joining the reinforcing layer 14 and the Fresnel lens sheet 40.
For the bonding layer 13, a thermoplastic resin such as an acrylic resin or a polyester resin, a curable resin such as an epoxy resin, a urethane resin, or an ionizing radiation curable resin can be used.
The bonding layer 13 can be used as a pressure-sensitive adhesive layer, an adhesive layer, or the like.

  In the present embodiment, the bonding layer 13 for bonding the semi-cured hard coat layer 21 </ b> A and the light diffusion layer 11 is formed as a constituent layer of the transfer foil 20. The bonding layer 13 in contact with the semi-cured hard coat layer 21A is preferably made of a thermoplastic resin in order to easily thermally bond the transfer foil 20 by heating at the time of transfer, but it has durability such as heat resistance at the end product. In consideration of the properties, it is preferable to use a post-curing type curable resin that can be heat-sealed when an acrylic resin or the like is bonded. However, in the present invention, the bonding layer 13 for the semi-cured hard coat layer 21A may be applied and adhered to the light diffusion layer 11 side.

[Light diffusion layer 11]
The light diffusion layer 11 is a layer that diffuses the image light incident from the light incident surface side Lin, isotropically diffused, and emits the light from the light output surface side Lout to reach the observer. The light diffusing layer 11 may be made of a known material and a forming method. For example, the light diffusion layer 11 is composed of a base material made of a transparent resin and a diffusion component dispersed in the base material. The light diffusing layer 11 diffuses light isotropically by the refractive index difference between the base material and the diffusing component, or by the reflectivity of the diffusing component itself.
In the present invention, the light diffusing layer 11 may have an aspect in which light is anisotropically diffused in addition to an aspect in which light is isotropically diffused. For example, anisotropic diffusion is performed by adjusting the shape of the diffusion component and the distribution in the base material.
In the present invention, the laminate 10 is preferably a laminate in which at least the light diffusion layer 11, the semi-cured hard coat layer 21 </ b> A, and the peelable support 22 are laminated.

  Examples of the base material that can be used include acrylic resins such as methyl methacrylate-butadiene-styrene copolymer (MBS resin) and methyl methacrylate-styrene copolymer (MS resin), and polycarbonate resins.

  Examples of the diffusion component include resin beads and bubbles. Among them, resin beads are preferable, and those having high transparency are particularly preferable. Examples of such resin beads include acrylic beads, melamine beads, acrylic-styrene beads, polycarbonate beads, polyethylene beads, and polystyrene beads. Among them, acrylic beads are preferable.

The light diffusion layer 11 can be formed by, for example, extruding a resin composition in which the diffusion component is dispersed in the base material.
The thickness of the light diffusion layer 11 is 0.1 to 2 mm, more preferably 0.2 to 1.5 mm. If the thickness is less than this range, the light diffusing ability of the light diffusing layer 11 may be insufficient. If the thickness exceeds this range, the resolution of the image displayed on the curved screen for the rear transmission type display is deteriorated and blurred. There is.

[Optical control layer 30]
The optical control layer 30 is a layer having a function of appropriately absorbing stray light and external light while controlling the optical path of the image light incident from the light incident surface side Lin. The optical control layer 30 can improve image contrast. The optical control layer 30 is provided according to the necessity of optical control. As the optical control layer 30, a known material and a formation method can be used.
The optical control layer 30 includes a large number of light absorbing portions 31 arranged along the layer surface so as to absorb light, and a light transmitting portion 32 arranged so as to transmit light between the light absorbing portions 31. Have. In the cross-sectional view of FIG. 2, the light absorbing portions 31 extend in a direction perpendicular to the paper surface and are arranged at a constant cycle in the left-right direction of the paper surface. The cross-sectional shape of the light absorbing portion 31 in the present embodiment is an isosceles triangle shape as shown in the figure, and the bottom surface side is formed toward the light exit surface side Lout. Further, in the present embodiment, as shown in the figure, the respective light transmitting portions 32 between the light absorbing portions 31 are connected to each other on the apex side of the isosceles triangular light absorbing portion 31. .
In the present invention, the cross-sectional shape of the light absorbing portion 31 and the cross-sectional shape of the light transmitting portion 32 may take various shapes such as a trapezoidal shape in accordance with the light beam control specifications.
Moreover, the relationship between the refractive index Nb of the light absorption part 31 and the refractive index Np of the light transmission part 32 is determined according to the required optical control specification. Usually, the difference in refractive index between the refractive index Nb and the refractive index Np of the light transmitting portion 32 is greater than 0 and 0.06 or less.

[Light absorber 31]
The light absorbing portion 31 is composed of light absorbing particles and a binder in which the light absorbing particles are dispersed. The light absorbing particles act to absorb stray light and external light. The light absorption part 31 can be formed of a light absorption part forming composition in which light absorption particles are dispersed in a binder.

As the light-absorbing particles, light-absorbing colored particles such as carbon black are preferably used, but the light-absorbing particles are not limited to these, and colored particles that selectively absorb a specific wavelength according to the characteristics of the image light. May be used.
Specific examples of such light absorbing particles include organic fine particles colored with metal salts such as carbon black, graphite and black iron oxide, dyes, pigments, colored glass beads, and the like. In particular, colored organic fine particles are preferable from the viewpoints of cost, quality, availability, and the like. More specifically, acrylic crosslinked fine particles containing carbon black, urethane crosslinked fine particles containing carbon black, and the like are preferable.
Such colored particles are usually contained in an amount of 3 to 30% by mass in the light absorbing part forming composition. The average particle diameter of the colored particles is preferably 1.0 to 20 μm.

  In addition, in this invention, in order to provide the light absorption part, the light absorption part 31 may make light absorption part the whole light absorption part with dye other than a light absorption particle.

  As the binder, a resin that is cured by light such as ultraviolet rays is preferable. For example, an acrylate-based ionizing radiation curable resin can be used. As the ionizing radiation curable resin, a composition containing a monomer, a prepolymer, a photopolymerization initiator and the like is preferably used.

[Light transmission part 32]
The light transmission part 32 can be comprised by the binder of the component remove | excluding the light absorption particle from the light absorption part formation composition which comprises the above-mentioned light absorption part 31. FIG. The binder used may be the same as that of the light absorption part 31.

[Method of Forming Light Absorbing Portion 31 and Light Transmitting Portion 32]
The light absorbing portion 31 is formed by filling a groove formed on the surface of the light transmitting portion 32 with a light absorbing portion forming composition containing colored particles by a so-called wiping method, and using a doctor blade. It can be formed by scraping the light-absorbing part forming composition.
The groove of the light transmitting portion 32 can be formed by a photopolymer method (also referred to as 2P method) using an ionizing radiation curable resin and a mold. At this time, a cylindrical mold is used as the mold, and the ionizing radiation curable resin is cured in a state where the ionizing radiation curable resin is sandwiched between the mold and the base material layer 12, thereby continuously forming the ionizing radiation curable resin on the base material layer 12. The light transmission part 32 can be formed.

[Base material layer 12]
The base material layer 12 is a layer used as a base material when forming various layers. In this embodiment, the base material layer 12 is used for the optical control layer 30 and a Fresnel lens layer 41 described later.
For the base material layer 12, for example, a transparent resin such as a polycarbonate resin, an acrylic resin, triacetyl cellulose (TAC), or a cycloolefin resin can be used. Among these, the polycarbonate-based resin is a kind of resin that is preferable in terms of availability, cost, adhesion, and the like. Here, the polycarbonate resin is a resin having polycarbonate as a main polymer, and may contain a filler such as a deterioration inhibitor, a plasticizer, and a softener, and may be a composite with an acrylic resin or the like.

For the purpose of enhancing the adhesion between the base material layer 12 and the adjacent layer, the surface of the base material layer 12 may be subjected to a known adhesion strengthening treatment such as formation of a primer layer.
The thickness of the base material layer 12 is set according to the target layer, and is, for example, 25 to 200 μm.

[Reinforcing layer 14]
The reinforcing layer 14 is insufficient in mechanical strength as the curved screen 100 for a back-transmission display to be manufactured, and cannot maintain a predetermined curved shape, or the image is distorted. This layer is provided to increase rigidity and eliminate such problems when it is unintentionally deformed and the handling and quality are hindered.
The material and thickness of the reinforcing layer 14 are set so that such rigidity can be obtained.
The material of the reinforcing layer 14 is a transparent resin, for example, a polycarbonate resin, or an acrylic resin such as methyl methacrylate-butadiene-styrene copolymer (MBS resin), methyl methacrylate-styrene copolymer (MS resin). Among them, from the viewpoint of heat resistance and the like, a polycarbonate resin is a kind of a preferable resin.
The thickness of the reinforcement layer 14 can be 3-5 mm, for example. If the thickness is too thick, the transmittance of image light may decrease, ghost (double image) may occur, or optical performance may decrease.

[Fresnel lens sheet 40]
The Fresnel lens sheet 40 is a sheet in which a Fresnel lens layer 41 is formed on the base material layer 12.

[Base material layer 12]
The base material layer 12 is a layer that becomes a base material for forming the Fresnel lens layer 41. Since the base material layer 12 has already been described, the description thereof will be omitted.

  However, in the present invention, the base material layer 12 is not essential for the Fresnel lens layer 41. The base material layer 12 adjacent to the Fresnel lens layer 41 may be omitted, and only the Fresnel lens layer 41 may be provided as the curved screen 100 for the rear transmission type display. For example, the laminate 10 shown in FIG. 3 has a configuration in which the Fresnel lens layer 41 is laminated directly adjacent to the reinforcing layer 14. The other layer portions of the laminate 10 shown in FIG. 3 are the same as those in FIG. Such a configuration is formed, for example, by using the reinforcing layer 14 instead of the base material 12 when the Fresnel lens layer 41 is formed.

[Fresnel lens layer 41]
The Fresnel lens layer 41 is a layer that forms a Fresnel lens by including a plurality of unit lenses. The Fresnel lens layer 41 converts the image light incident from the light incident surface side Lin as a divergent light beam from the image light source into a parallel light beam that travels toward the light exit surface side Lout that is the viewer side of the curved screen 100 for the rear transmission type display. To do. By converting the image light into a light beam substantially perpendicular to the screen surface, unevenness in the brightness of the image is suppressed.
The Fresnel lens layer 41 may be a circular Fresnel lens in which unit lenses are arranged concentrically or arcuately, or a linear Fresnel lens in which unit lenses extending in a straight line are arranged in parallel.

As the Fresnel lens layer 41, a known material and a forming method can be used.
The Fresnel lens layer 41 is made of a transparent resin. As the transparent resin, for example, an acrylic resin, a styrene resin, a polyester resin, a polycarbonate resin, an acrylic-styrene copolymer resin, or the like can be used.

The method for forming the Fresnel lens layer 41 is not particularly limited. For example, the Fresnel lens layer 41 can be formed by forming a unit lens on the base material layer 12 by the photopolymer method (2P method) in the same manner as the light transmitting portion 32 described above. For example, if an acrylate ionizing radiation curable resin is used and formed by a photopolymer method, the Fresnel lens layer 41 made of an acrylic resin is formed.

[Other layers]
In this invention, the laminated body 10 can contain the other layer in a conventionally well-known back surface transmission type screen suitably other than an above-described layer. For example, an antireflection layer, an antistatic layer, a colored layer, and the like.

<< First curved surface forming process >>
As shown in FIG. 1 (B), the first curved surface forming step is a lamination in which a flat and semi-cured semi-cured hard coat layer 21A prepared in the laminate preparation step is laminated as a transfer foil 20. This is a process of forming the body 10 and bending it to form a three-dimensional curved surface.
In the present embodiment, the laminate 10 is a light emitting surface side Lout facing the observer side on the transfer foil 20 side (upward in the drawing) including the semi-cured hard coat layer 21A, and the light emitting surface side Lout is convex. To form a three-dimensional curved surface.

The three-dimensional curved surface means a surface that is partially or wholly bent around a plurality of axes inclined with respect to each other. On the other hand, a two-dimensional curved surface means a surface that is bent two-dimensionally around a single axis.
In the present embodiment, a three-dimensional curved surface is formed into a shape of a part of a spherical surface of a sphere. However, in the present invention, the three-dimensional curved surface is not limited to a spherical surface, but may be any shape such as an elliptical sphere or a curved surface whose section forms a parabola. The curved surface shape of the three-dimensional curved surface is in accordance with the application to which the curved screen for rear transmissive display is applied.
The curved surface screen 100 for rear transmissive display according to the present invention may have a curved surface with a radius of curvature of 200 cm or less, preferably 25 to 150 cm.

  In the present invention, the light exit surface side Lout may be curved so as to be a concave curved surface. Whether the light-emitting surface side Lout is a convex curved surface or a concave curved surface depends on a device in which the curved surface screen 100 for rear transmission type display is incorporated.

The curved surface forming can be performed by a forming method using air pressure such as vacuum forming, pressure forming, or vacuum / pressure forming while the laminate 10 is heated.
The mold M shown in FIG. 4A may have either a convex curved surface (male) or a concave curved surface (female) shown in FIG. 4B.
However, in the embodiment in which the laminate 10 has the Fresnel lens layer 41 as in the present embodiment, the Fresnel lens layer 41 side entrance is arranged so that the lens does not deform due to the Fresnel lens layer 41 coming into contact with the mold surface when the curved surface is molded. The surface to be the light surface side Lin is preferably molded in a form that does not contact the mold surface.
Therefore, in this embodiment, the light emitting surface side Lout on which the transfer foil 20 is laminated is brought into contact with the mold surface. Therefore, a mold having a concave curved surface is used.
In the present invention, when the laminated body 10 does not include the Fresnel lens layer 41, a concave curved surface (female) mold M shown in FIG. 4B or a mechanical pressure shown in FIG. 4C. It is also possible to use press molding in which a mold surface is brought into contact with both side surfaces of the laminated body 10 and pressed.

  The heating temperature of the laminate 10 is preferably not less than the glass transition temperature Tg of the layer having the highest glass transition temperature Tg among the layers constituting the laminate 10, for example, not less than 120 ° C. and not more than 180 ° C.

Thus, when the first curved surface forming step is performed, the hard coat layer in the laminate 10 is a semi-hardened hard coat layer 21A. Even when curved and stretched, cracks do not occur and optical quality does not deteriorate.
Further, in the present embodiment, since ionizing radiation is used in the curing progressing process and thermosetting is used during the previous semi-curing, the curing progresses unintentionally due to heat during curved surface molding, and cracks are likely to occur. The manufacturing conditions do not become unstable.

<< Curing progress process >>
As shown in FIG. 1C, the curing progress step is a step of proceeding with the remaining curing of the ionizing radiation curable resin in the semi-cured hard coat layer 21A after the first curved surface forming step.
In this embodiment, ionizing radiation E is used to advance curing. Here, ultraviolet rays are used as the ionizing radiation E. It is preferable that the ionizing radiation E is applied to the laminate 10 from the light exit surface side Lout closer to the surface of the semi-cured hard coat layer 21 </ b> A in terms of less energy loss.

  In the curing progress step, the curing of the ionizing radiation curable resin constituting the semi-cured hard coat layer 21A can be completed. In the present invention, it is not essential to complete the curing in the curing progressing step. For example, you may further perform what is called an aging process which advances post-curing over time on the conditions for about 1 day-about 7 days at the temperature of about 40-60 degreeC.

《Support peeling process》
As shown in FIG. 1D, the support peeling step is a step of peeling the peelable support 22 in the transfer foil 20 after the curing progressing step. The transfer of the transfer foil 20 is completed by the support peeling process. The peelable support 22 is peeled from the hard coat layer 21 formed by curing, whereby the cured hard coat layer 21 becomes a surface layer. A screen 100 is manufactured.
In the present invention, the peelable support 22 is peeled after the curing progressing step, but the curing is further advanced to some extent as compared to before the curing progressing step and after the first curved surface forming step. The latter is preferable in that the peelable support 22 can be easily peeled off. In this regard, when the aging is performed, the support peeling process may be performed after aging.

  According to the present embodiment as described above, the curved surface screen 100 for rear transmission type display having the hard coat layer 21 on the surface can be manufactured while suppressing the occurrence of cracks in the hard coat layer 21. In addition, since the hard coat layer 21 is formed of a transfer foil regardless of spray coating, dust can be prevented from being bitten, drying time is not required, and productivity is good.

<< B >> Second Embodiment With reference to FIG. 5, a second embodiment of the method of manufacturing the curved screen for rear transmissive display of the present invention will be described. The present embodiment shown in FIG. 5 differs from the above-described first embodiment shown in FIG. 1 in that the laminate 10 does not include the Fresnel lens sheet 40, and the laminate 10 and the Fresnel. After the lens sheet 40 and the lens sheet 40 are separately curved, they are laminated, and the Fresnel lens layer 41 of the Fresnel lens sheet 40 is formed on the light exit surface side Lout, as in the curved screen 100 for a rear transmission type display shown in FIG. To face.

<< Laminated body preparation process >>
In the present embodiment, the laminate 10 prepared in the laminate preparation step shown in FIG. 5A is, as shown in FIG. 6A, a Fresnel lens sheet 40 and a joint that is disposed adjacent to the laminate. The second embodiment is the same as the first embodiment except that the layer 13 is not provided. Therefore, the further description regarding a laminated body preparation process is abbreviate | omitted.

<< First curved surface forming process >>
In the first curved surface forming step shown in FIG. 5B, in the present embodiment, the laminate 10 does not include the Fresnel lens sheet 40, so the lens does not deform due to the Fresnel lens layer 41 contacting the mold surface during the curved surface forming. Similarly, it is not necessary to devise a method of forming the surface that is the light incident surface Lin on the Fresnel lens layer 41 side so as not to contact the mold surface. Therefore, in this embodiment, either surface of the laminate 10 may be brought into contact with the mold surface, and mechanical hot press molding can be used.
However, in the mold M, the convex surface (male) of the mold surface shown in FIG. 4A is more preferable than the concave curved surface (female type) shown in FIG. The reason for this is that in the case of a convex curved surface (male), the central portion of the laminate 10 first contacts the top of the convex curved surface, so that the laminate 10 in this part is less deformed than the other parts and is less than other parts. Because it will not be thin. This is because when the laminated body 10 becomes the curved surface screen 100 for a rear transmission type display, if the central portion of the screen becomes thin, the brightness and viewing angle of the image may be greatly affected.

<< Curing progress process >>
The curing progress step shown in FIG. 5C is the same as that in the first embodiment. Therefore, further explanation is omitted.

《Fresnel lens sheet preparation process》
The Fresnel lens sheet preparation step shown in FIG. 5D is a step of preparing a flat Fresnel lens sheet 40. It is preferable that the Fresnel lens sheet 40 prepared in this step has a certain degree of rigidity in consideration of handling at the time of curved surface molding in the second curved surface molding step.
Therefore, in the present embodiment, as shown in FIG. 6B, as the Fresnel lens sheet 40, the reinforcing layer 14 is further laminated via the bonding layer 13 on the substrate layer 12 on which the Fresnel lens layer 41 is laminated. Are used to increase the rigidity.
Since the layers constituting the Fresnel lens sheet 40 have already been described, further description will be omitted.
In the present invention, the flat Fresnel lens sheet 40 prepared in the Fresnel lens sheet preparation step only needs to have appropriate rigidity and good handleability, and the base material layer 12 and the reinforcing layer 14 are not essential.

<< Second curved surface forming step >>
The second curved surface forming step shown in FIG. 5 (E) is a step of bending the flat Fresnel lens sheet 40 prepared in the Fresnel lens sheet preparing step so as to form a three-dimensional curved surface.
In the present embodiment, the Fresnel lens layer 41 is bent so as to be on the light exit surface side Lout and on the convex side. For this reason, it shape | molds in the format which the reinforcement layer 14 side contacts the type | mold surface of the convex curve of a shaping | molding die. For this reason, in the present embodiment, as in the first curved surface forming step in the second embodiment, the elongation and deformation of the central portion can be reduced as compared with the case where the concavities and convexities are reversed, and the manufactured rear surface transmission. The display can be molded without greatly affecting the brightness and viewing angle of the image at the center of the curved screen 100 for a mold display.

<< Lamination process >>
The lamination process shown in FIG. 5 (F) includes the laminate 10 bent so as to form a three-dimensional curved surface in the first curved surface forming process, and the three-dimensional curved surface formed in the second curved surface forming process. This is a step of laminating the obtained Fresnel lens sheet 40. From the lamination step, a laminate 10a having a three-dimensional curved surface in which the laminate 10 and the Fresnel lens sheet 40 are laminated is produced.
In this embodiment, a lamination process is implemented after a hardening progress process. However, in this invention, you may implement a hardening progress process after a lamination process.

The laminated body 10 and the Fresnel lens sheet 40 may be cut into appropriate sizes and shapes before being laminated.
The plan view shape when the rear transmission display curved screen 100 is finally obtained is a shape corresponding to the installation part of the device in which the rear transmission display curved screen 100 is installed, for example, rectangular or circular. , Oval and so on are arbitrary.

In the present embodiment, the Fresnel lens sheet 40 and the laminate 10 are laminated with the Fresnel lens layer 41 of the Fresnel lens sheet 40 facing the laminate 10.
However, since the Fresnel lens layer 41 may rub against the laminate 10 and damage the laminate 10, a slip agent such as silicone oil is applied to the surface of the laminate 10 that contacts the Fresnel lens layer 41. It is preferable to keep it.
Further, if the gap between the Fresnel lens layer 41 and the laminated body 10 becomes large, a ghost (double image) may occur in the curved surface screen 100 for rear transmission type display. Therefore, the laminated body 10 and the Fresnel lens layer. 41 is preferably kept in contact.
The method of laminating the laminated body 10 and the Fresnel lens sheet 40 is not particularly limited. For example, a method of superposing the Fresnel lens sheet 40 and the laminated body 10 and fixing the peripheral portion between them with a metal clip is mentioned. It is done.

《Support peeling process》
The support peeling process shown in FIG. 5 (G) is a process of peeling the peelable support 22 in the portion formed as the transfer foil 20 from the laminated body 10a obtained in the lamination process. The transfer of the transfer foil 20 is completed by the support peeling process. The rear transmissive display having a desired configuration in which the hard coat layer 21 that has already been cured has become a surface layer by peeling the peelable support 22 from the hard coat layer 21 that has been cured. A curved screen 100 is produced.

  According to the present embodiment as described above, the curved surface screen 100 for rear transmission type display having the hard coat layer 21 on the surface can be manufactured while suppressing the occurrence of cracks in the hard coat layer 21. In addition, since the hard coat layer 21 is formed of a transfer foil regardless of spray coating, dust can be prevented from being bitten, drying time is not required, and productivity is good. Further, since the laminate 10 and the Fresnel lens sheet 40 are separately molded, there are few restrictions on the molding method for molding so that the Fresnel lens layer 41 does not contact the mold surface of the mold.

<< C >> Others As described above, the present invention has been described with reference to the first embodiment and the second embodiment. However, the present invention is applicable to any curved surface that does not cause cracks in the hard coat layer during molding. Although not belonging to, the hard coat layer does not have to be semi-cured at the time of molding. Even in such a manufacturing method, since the hard coat layer is formed of a transfer foil regardless of spray coating, dust can be prevented from being bitten, drying time is not required, and productivity is good. By adopting the transfer foil, in this case, the transfer foil in the laminate preparation process uses a hard coat layer made of a resin cured product in which the hard coat layer is not semi-cured but has been cured, and the subsequent curing progress process is omitted. Is done. The resin described in the first embodiment may be used as the resin for the hard coat layer.
However, according to the present invention, even if the screen is a curved surface, it can be produced while stably preventing cracks in the hard coat layer.

DESCRIPTION OF SYMBOLS 10 Laminated body 10a Laminated body 11 Light-diffusion layer 12 Base material layer 13 Joining layers (an adhesive layer, an adhesive layer, etc.)
DESCRIPTION OF SYMBOLS 14 Reinforcement layer 20 Transfer foil 21 Hard coat layer 21A Semi-hardened hard coat layer 22 Peelable support 30 Light control layer 31 Light absorption part 32 Light transmission part 40 Fresnel lens sheet 41 Fresnel lens layer 100 Curved screen for rear transmission type display E Ionizing radiation Lin Light incident surface side Lout Light emission surface side M Mold

Claims (4)

A method of manufacturing a curved screen for a rear transmissive display, comprising a laminate that forms a curved surface shape by transmitting image light incident from the light incident surface side to the light exit surface side,
As the laminate, a laminate prepared by preparing a laminate in which a transfer foil is laminated and the transfer foil is a transfer foil having a hard coat layer formed on a peelable support. Process,
Including a first curved surface forming step of forming and bending the flat laminate prepared in the laminated body preparation step so as to form a three-dimensional curved surface,
The ionizing radiation curable resin constituting the hard coat layer in the laminate preparation step is in a semi-cured state,
After the first curved surface forming step, the curing progressing step of advancing the curing of the ionizing radiation curable resin of the hard coat layer,
After the curing progressing step, the peelable support of the transfer foil is peeled off, a support peeling step,
A method of manufacturing a curved screen for a rear transmission type display.   The laminated body includes a light control layer having a light absorption part arranged along a layer surface so as to be able to absorb light, and a light transmission part arranged so as to be able to transmit light between the light absorption parts. Item 2. A method for producing a curved screen for rear transmission display according to Item 1.   The manufacturing method of the curved surface screen for back transmissive display of Claim 1 or 2 with which the said laminated body contains a Fresnel lens layer in the most light-incidence surface side of the said laminated body. Preparing a Fresnel lens sheet having a Fresnel lens layer, a Fresnel lens sheet preparation step,
A second curved surface molding step of forming and bending the Fresnel lens sheet to form a three-dimensional curved surface;
The light-incident surface side of the laminate that has been bent so as to form a three-dimensional curved surface in the first curved surface forming step, and that is bent so as to form a three-dimensional curved surface, prepared in the second curved surface forming step. Laminating a Fresnel lens sheet,
Before or after the laminating step, including a step of curing the hard coat layer,
The manufacturing method of the curved screen for backside transmissive displays of Claim 1 or 2.

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