JP6221319B2 - Method for manufacturing transmissive curved screen - Google Patents

Description

  The present invention relates to a method of manufacturing a transmissive curved screen that displays video by transmitting video 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 a field such as an amusement machine and an automobile. In these fields, in addition to the function of simply displaying images, the design in harmony with the whole is regarded as extremely important. For this reason, the display surface of the display may be required to have a curved surface instead of a flat surface. However, since a liquid crystal display panel uses a glass substrate, it is difficult to make the display surface curved. Therefore, a transmissive curved screen has been proposed in which a screen made of a resin sheet or the like has a curved shape (Patent Document 1).

  In order to make the transmissive screen have a curved surface shape, it is necessary to perform some curved surface forming to form a flat sheet for forming a curved surface. The curved surface forming is usually performed by a forming method using atmospheric pressure as a forming pressure applied to a forming die and a forming sheet, such as vacuum forming, pressure forming, or vacuum / pressure forming. The molding die is usually provided with a plurality of vent holes in order to allow air sandwiched between the mold surface and the molding sheet to escape to the outside. The ventilation hole is, for example, a circular hole having a diameter of about 0.5 mm.

FIG. 8 is an explanatory view showing an example of conventional curved surface molding. In this figure, the molding die 54 has a stepped shape, but the molding is the same even if it has a curved shape. First, as shown in FIG. 8A, the molding sheet 51 is heated and softened. The outer periphery of the molding sheet 51 is held by a fixed frame 52. The forming sheet 51 is heated by an infrared heater 53.
Next, as shown in FIG. 8 (b), the heat-softened forming sheet 51 is moved onto the forming die 54, and thereafter, as shown in FIG. The molding sheet 51 has a shape that follows the shape of the mold surface of the molding die 54. At this time, air is sucked from a plurality of vent holes provided in the mold surface of the mold 54. The molding sheet 51 is pressed against the mold surface of the molding die 54 by a pressure difference that increases the atmospheric pressure applied to the opposite side of the molding die 54 with respect to the atmospheric pressure applied to the molding die 54 side of the molding sheet 51. The curved surface is molded into the shape of the mold surface.
Next, as shown in FIG. 8D, after the molding sheet 51 is cooled until the curved shape can be maintained, the molding sheet 51 is molded as shown in FIG. Separated from the mold 54. And as shown in FIG.8 (f), the surrounding unnecessary part is cut and removed by the cutters 55, such as a laser and a cutter, in the shaping | molding sheet | seat 51 after curved-surface shaping | molding. In this way, a molded product having a curved surface shape is obtained by the curved surface molding.

JP 2012-32513 A

  However, a trace of a vent hole may remain on the surface of the sheet after forming the forming sheet into a curved surface. For example, traces of vent holes with a diameter of about 0.2 mm are generated.

  Such traces of the air holes lower the quality of the displayed image on the transmissive curved screen that displays the image. In particular, display devices such as amusement machines and automobiles have a problem in that the display quality is deteriorated even when the image is about 0.2 mm because the image is watched near the screen.

  That is, an object of the present invention is to provide a method for producing a transmissive curved screen in which traces of vent holes in a molding die are hardly noticeable even when curved molding is performed using a molding die and atmospheric pressure.

The transmission curved screen manufacturing method according to the present invention has the following configuration.
(1) A transmissive curved screen having a curved surface laminate having a curved surface shape and transmitting image light incident from the light incident surface side to the light exit surface side,
The curved laminate includes, in order from the light exit surface side, at least a light diffusion layer and a light control layer. The light control layer includes a light absorbing portion arranged along the layer surface so as to be able to absorb light, and the light. A light transmission portion arranged to transmit light between the absorption portions,
A method of manufacturing a transmissive curved screen,
Preparing a laminate for molding before molding into the curved surface shape, a laminate preparation step,
A first curved surface forming step in which the molded laminate is formed into a curved surface by forming a curved surface using a mold and atmospheric pressure;
Including
By the first curved surface forming step, the mold have a plurality of vent holes in the mold surface by the mold material itself is a porous material, and the molding mold surface has a convex curved surface,
Method for manufacturing transmissive curved screen

(2) The method for producing a transmissive curved screen according to (1), wherein the molding laminate includes a Fresnel lens layer having a lens surface facing the light incident surface side on the light incident surface side.

(3) having a Fresnel lens layer, preparing a Fresnel lens sheet for molding before molding into the curved surface shape formed by the curved laminate, a Fresnel lens sheet preparation step;
A second curved surface molding step, wherein the molding Fresnel lens sheet is formed into a curved surface using a molding die to form a curved Fresnel lens sheet having the curved surface shape;
Laminating the curved Fresnel lens sheet on the light incident surface side of the curved laminate, and a laminating step;
Including
In the second curved surface molding step, the mold has a plurality of ventilation holes on the mold surface because the mold material itself is a porous material.
(1) The manufacturing method of the transmissive | pervious curved screen of said.
(4) The manufacturing method of the transmissive | pervious curved screen of any one of Claims 1-3 whose hole diameter of the said air vent is 10-30 micrometers.

  According to the present invention, it is possible to manufacture a transmissive curved screen in which the traces of the vent holes of the mold M are not noticeable even if the curved surface is molded using the mold and the atmospheric pressure.

Explanatory drawing explaining the manufacturing method of the transmission type curved screen by this invention with a basic form. Sectional drawing (a) which shows the laminated body for shaping | molding in 1st Embodiment, and sectional drawing (b) which shows a curved-surface laminated body and a transmissive | pervious curved screen. Explanatory drawing which shows an example of the shaping | molding apparatus which can implement the vacuum press method which can be utilized for the manufacturing method of the transmission type curved screen by this invention. Sectional drawing which shows the layer structure of the transmissive | pervious curved screen obtained in 2nd Embodiment. Sectional drawing which shows the deformation | transformation example of a laminated body for shaping | molding, a curved-surface laminated body, and a transmissive | pervious curved screen. Sectional drawing which shows the deformation | transformation example of a laminated body for shaping | molding, a curved-surface laminated body, and a transmissive | pervious curved screen. Sectional drawing which shows an example of the display apparatus using the transmissive | pervious curved screen by this invention. Explanatory drawing explaining an example of the conventional manufacturing method of a transmissive | pervious curved screen.

    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, FIG2 and FIG.3, 1st Embodiment of the manufacturing method of the transmissive | pervious curved screen of this invention is described.
FIG. 1 is an explanatory view for explaining a method of manufacturing a transmissive curved screen according to the present invention in a basic form. FIG. 2A is a cross-sectional view showing the molding laminate in the first embodiment, and FIG. 2B is a cross-sectional view showing the curved laminate and the transmissive curved screen in the first embodiment. FIG. 3 is an explanatory diagram illustrating an example of a molding apparatus capable of performing a vacuum press method that can be used in curved surface molding according to the first embodiment.

In the method of manufacturing a transmissive curved screen according to the present invention, a transmissive curved screen 20 that includes a curved laminate 10 having a curved surface shape and transmits image light incident from the light incident surface to the light exit surface is manufactured.
In the present invention, the curved laminate 10 includes at least a light diffusion layer 1 and a light beam control layer 2 in order from the light exit surface side Lout, as shown in FIG. The light absorption part 2a arranged along the layer surface so that absorption is possible, and the light transmission part 2b arranged so that light can permeate | transmit between the light absorption parts 2a. The layer surface is the surface of the light control layer 2.
The light diffusion layer 1 forms image light and emits it as diffused light to the light exit surface Lout.
The light beam control layer 2 has 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.

In the method of manufacturing a transmissive curved screen according to the present invention, as shown in FIG. 1 (b), a laminate preparation step for preparing a molding laminate 10A before molding into a curved shape formed by the curved laminate 10, and FIG. As shown in FIG. 1 (c), at least a first curved surface forming step is carried out by forming the laminated body 10 </ b> A into a curved laminated body 10 by forming a curved surface using the mold M and the atmospheric pressure. Moreover, in the present invention, in the first curved surface molding step, the mold M has a plurality of vent holes on the mold surface because the mold material itself is a porous material.
As a result, as shown in FIG. 1 (d), a curved laminate 10 is obtained. If this is used as it is, a transmissive curved screen 20 can be obtained at the same time. Moreover, if it has an additional process, after passing through an additional process, the curved-surface laminated body 10 and the transmissive | pervious curved screen 20 are obtained.

  In the drawings showing the layer structure of the curved laminated body 10, in the other drawings including FIG. 1 (a), the original curved surface shape is drawn two-dimensionally for convenience.

  In the present invention, as a result of the manufacturing method having such a configuration, the transmissive curved screen 20 provided with the curved laminate 10 is manufactured by curved molding using the molding die M and atmospheric pressure. The trace of the vent can be made inconspicuous.

In the present embodiment, specifically, a molding laminate 10A having the configuration shown in the cross-sectional view of FIG. The molding laminate 10A shown in the figure has a transparent base layer 3 and a bonding layer 4 in addition to the light diffusion layer 1 and the light control layer 2, and as a result, the layer configuration is the light exit surface side Lout. The light diffusion layer 1, the bonding layer 4, the light beam control layer 2, and the transparent base material layer 3 are formed in this order.
The transparent base material layer 3 functions as a base material at the time of creating the light beam control layer 2 and increases the mechanical strength of the curved laminate 10.
The bonding layer 4 bonds both layers adjacent to each other with the bonding layer 4 interposed therebetween.
In the present embodiment, after the molding laminate 10A is curved-shaped, the curved laminate 10 in which the hard coat layer is applied as the surface layer 5 on the light-emitting surface side Lout is manufactured as the transmissive curved screen 20.

  Hereinafter, a 1st embodiment is explained in full detail from a layered product preparation process in order of a process.

<< Laminated body preparation process >>
The laminated body preparing step is a step of preparing a molding laminated body 10A before molding into a curved shape, which is the basis of the curved laminated body 10 having the curved shape provided in the transmission curved screen 20.
In this embodiment, the molding laminate 10A has the layer configuration shown in the cross-sectional view of FIG. 2A. The light diffusion layer 1, the bonding layer 4, and the light control layer are sequentially formed from the light exit surface side Lout. 2. A transparent base material layer 3 is provided.
The shape of the molding laminate 10A is a flat plate shape in the present embodiment.

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

[Light diffusion layer 1]
The light diffusion layer 1 is a layer that distributes 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 1 may be made of a known material and a forming method. For example, the light diffusion layer 1 includes a base material made of a transparent resin and a diffusion component dispersed in the base material. The light diffusing layer 1 diffuses light isotropically by the difference in refractive index between the base material and the diffusing component or the reflectivity of the diffusing component itself.
In the present invention, the light diffusing layer 1 may have an aspect in which light is anisotropically diffused in addition to an aspect in which light isotropically diffuses. For example, anisotropic diffusion is performed by adjusting the shape of the diffusion component and the distribution in the base material.

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

  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, polystyrene beads, and silicone beads. Among them, acrylic beads are preferable.

The light diffusion layer 1 can be formed, for example, by extruding a resin composition in which the diffusion component is dispersed in the base material. The light diffusion layer 1 can be prepared in the form of a sheet by extrusion molding.
The thickness of the light diffusion layer 1 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 diffusion layer 1 may be insufficient. If the thickness exceeds this range, the resolution of the image displayed on the transmissive curved screen 20 is lowered and blurred. is there.

[Light control layer 2]
The light beam control layer 2 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 light control layer 2 can improve the contrast of the image. The light control layer 2 is basically provided according to the necessity of optical control, but in the present invention, it is provided as an indispensable layer in order to improve display quality. The light control layer 2 may be made of a known material and a forming method.
The light control layer 2 includes a large number of light absorbing portions 2a arranged along the layer surface so as to be able to absorb light, and a light transmitting portion 2b arranged so that light can be transmitted between the light absorbing portions 2a. Have. In the cross-sectional views showing the light beam control layer 2 such as FIG. 1A and FIG. 2, the light absorbing portions 2a extend in a direction perpendicular to the paper surface and are arranged at a constant cycle in the left-right direction on the paper surface. The cross-sectional shape of the light absorbing portion 2a in the present embodiment is an isosceles triangular shape as shown in the figure, and is formed with its base side facing the light exit surface side Lout. Further, in the present embodiment, as shown in the figure, each light transmitting portion 2b between the light absorbing portions 2a is on the vertex side of the light absorbing portion 2a having an isosceles triangle shape, and below the vertex in the drawing. They are formed by being connected to each other at portions located as continuous layers.
In the present invention, the cross-sectional shape of the light absorbing portion 2a and the cross-sectional shape of the light transmitting portion 2b can take various shapes such as a trapezoidal shape according to the light beam control specifications.
Further, the relationship between the refractive index Na of the light absorbing portion 2a and the refractive index Nb of the light transmitting portion 2b is determined according to the required optical control specifications. Usually, the refractive index difference between the refractive index Na and the refractive index Nb of the light transmitting portion 2b is greater than 0 and 0.06 or less.

(Light absorption part 2a)
The light absorbing portion 2a 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 2a 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. It is because it is excellent in light absorption and adhesiveness with a binder.

  In addition, in this invention, in order to provide the light absorption part, the light absorption part 2a may make the whole light absorption part 2a light absorptive 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. Examples of the ionizing radiation curable resin include urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, acrylic acrylate and other acrylate prepolymers, multifunctional acrylate monomers, monofunctional acrylate monomers, vinyl The resin composition which consists of 1 or more types of polymeric compounds, such as a system-type monomer, can be used.

(Light transmission part 2b)
The light transmission part 2b can be comprised from 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 2a. The binder used may be the same as that of the light absorbing portion 2a.

(Method for forming light absorbing portion 2a and light transmitting portion 2b)
The formation method of the light absorption part 2a and the light transmission part 2b is not specifically limited, For example, a well-known formation method can be employ | adopted suitably. For example, the light absorbing portion 2a is filled with a light absorbing portion forming composition containing colored particles in a groove formed on the surface of the light transmitting portion 2b by a so-called wiping method while using a doctor blade. It can be formed by scraping the absorbent portion forming composition.
The groove of the light transmitting portion 2b 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 transparent substrate layer 3 to be described later. The light transmission part 2b can be continuously formed on the top.

[Transparent substrate layer 3]
The transparent base material layer 3 is a layer used as a base material when forming various layers. In the present embodiment, the transparent substrate layer 3 is used for the light beam control layer 2.
For the transparent substrate layer 3, 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, moldability, heat resistance, adhesion, and the like.

  In the present invention, the transparent substrate layer 3 is not essential and can be omitted. For example, the surface of the transparent substrate layer 3 is made peelable, the light control layer 2 is formed on the peelable surface, and then the light control layer 2 is peeled from the transparent substrate layer 3 to form the transparent substrate layer 3. This is a case where the laminated body 10A is not incorporated as a constituent layer.

For the purpose of enhancing the adhesion between the transparent base material layer 3 and the adjacent layer, the surface of the transparent base material layer 3 may be subjected to a known adhesion strengthening treatment such as formation of a primer layer or corona discharge treatment. .
The thickness of the transparent base material layer 3 is set according to the target layer, and is, for example, 25 μm to 5 mm.

[Junction layer 4]
The bonding layer 4 is a layer for bonding the layers on both sides thereof. The bonding layer 4 is provided according to the necessity for bonding.
In the present embodiment, the bonding layer 4 is used for bonding the light diffusion layer 1 and the light control layer 2. The bonding layer 4 can be used as an adhesive layer, an adhesive layer, or the like.
For the bonding layer 4, a thermoplastic resin such as an acrylic resin or a polyester resin, or a curable resin such as an epoxy resin, a urethane resin, or an ionizing radiation curable resin can be used.

  In the present invention, the bonding layer 4 can be omitted. For example, the bonding layer 4 between the light diffusion layer 1 and the light control layer 2 when the light diffusion layer 1 is applied to the light control layer 2.

[Method for Producing Molded Laminate 10A]
As a method of producing the molding laminate 10A, a known transmission screen manufacturing method can be applied. For example, in the present embodiment, after the light control layer 2 is formed by the 2P method and the wiping method on the transparent base material layer 3 made of a belt-shaped resin sheet, the bonding layer 4 is formed on the surface of the light control layer 2. The sheet | seat used as the light-diffusion layer 1 is laminated | stacked through the adhesive agent used.

<< First curved surface forming process >>
As shown in FIG. 1 (c), in the first curved surface forming step, the forming laminated body 10A prepared in the laminated body preparing step is formed into a curved surface shape using a forming die M and atmospheric pressure to form a curved surface shape. This is a process for forming the curved laminate 10.
For the mold M, a mold having a plurality of ventilation holes on the mold surface is used because the mold material itself is a porous material, and the molding is performed by a curved surface molding method using atmospheric pressure as the molding pressure. Examples of such curved surface forming methods include vacuum forming, pressure forming, and vacuum / pressure forming.

[What is "curved surface" in curved surface shape?]
In the present embodiment, the “curved surface” in the curved surface shape formed by the curved laminated body 10 is a “three-dimensional curved surface”. More specifically, in the present embodiment, the three-dimensional curved surface is a part of the spherical surface of the sphere.
In the present invention, the “curved surface” may be a “two-dimensional curved surface” in addition to the “three-dimensional curved surface”. In the use of the display device to which the transmissive curved screen 20 is applied, the “three-dimensional curved surface” and the “two-dimensional curved surface” are selectively used from the viewpoint of designability and a unified sense of designability as a whole.
“Three-dimensional curved surface” means a surface that is partially or wholly bent around a plurality of mutually inclined axes. The “three-dimensional curved surface” is not limited to a spherical surface, but may be an elliptical sphere, a curved surface whose section forms a parabola, or a curved surface of a combination thereof.
“Two-dimensional curved surface” means a surface that is bent two-dimensionally around a single axis.
The “curved surface” may be a combined curved surface of “three-dimensional curved surface” and “two-dimensional curved surface”.
The “curved surface” may be a combined curved surface of “convex curved surface” and “concave curved surface”.
Whether the convex side of the “curved surface” is the light exit surface side Lout or the light entrance surface side Lin is arbitrary.
With the curved surface shape, the “curved surface” may be in the whole area of the curved surface laminate 10 or may be in a part. That is, the curved surface shape is a shape having “curved surface” at least in part.
In the present invention, the radius of curvature of the “curved surface” depends on the application and design properties, but can be, for example, 200 cm or less, more specifically 25 to 150 cm.
Moreover, in a local case etc., a curvature radius can be 1-25 cm.

In the present embodiment, the curved surface is formed such that the light exit surface side Lout is a convex curved surface.
In the present invention, the light exit surface side Lout may be curved so as to be a concave curved surface. Whether the light exit surface side Lout is a convex curved surface or a concave curved surface depends on a device in which the transmissive curved screen 20 is incorporated.

[Heating of laminate 10A for molding]
The curved surface molding is performed after a heated state so that the molding laminate 10A is easily curved-surface molded.
The heating temperature of the molding laminate 10A 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 molding laminate 10A, for example, 120 ° C. or more and 180 ° C. or less. .

[Mold M]
As the mold M, a mold having a plurality of ventilation holes on the mold surface is used because the mold material itself is a porous material. As a specific example, the mold M may be a porous aluminum mold. As long as the mold material itself is a porous material, the mold M may be a mold using a metal other than aluminum, ceramics, or other composite materials.
The hole diameter of the ventilation hole brought about by the mold M being a porous material can be, for example, 5 to 100 μm, preferably 10 to 50 μm, more preferably 10 to 30 μm. When the hole diameter is less than the above range, the air holes are easily clogged, and when the hole diameter exceeds the above range, traces of the air holes are easily noticeable.

In the present invention, the mold M may have a convex curved surface (male), a concave curved surface (female), or a mold having both a convex curved surface and a concave curved surface.
In the present embodiment, since the molding laminate 10A does not include the molding Fresnel lens sheet 6A described later, either the light exit surface side Lout or the light entrance surface side Lin is brought into contact with the mold surface to be a curved surface. Can be molded.

However, in the mold M, the convex curved surface (male) is more preferable than the concave curved surface (female type). The reason for this is that in the case of a convex curved surface (male), the central portion of the molding laminate 10A first contacts the top of the convex curved surface, so that the molding laminate 10A in this part is less deformed than the other parts. It is because it does not become thinner than other parts. When the laminate 10A for molding becomes the curved laminate 10, and when the curved laminate 10 is incorporated into the transmissive curved screen 20, if the central portion of the screen becomes thin, the brightness and field of view of the image This is because there is a possibility of greatly affecting the corners.
Therefore, in consideration of this point, in order to manufacture the curved laminated body 10 having the light exit surface side Lout as the convex curved surface, the curved surface is formed so that the light incident surface side Lin contacts the mold surface of the convex curved surface. .

[Molding pressure: atmospheric pressure, etc.]
Various methods such as vacuum forming, pressure forming, and vacuum / pressure forming can be adopted as the curved surface forming method using atmospheric pressure as the forming pressure. What is necessary is just to employ | adopt the curved surface shaping | molding method which can be utilized in facilities.

Specific examples of known curved surface forming methods using atmospheric pressure include, for example, an overlay method (see Japanese Patent Publication No. 56-45768, Japanese Patent Laid-Open No. 4-36837), a vacuum pressing method (Japanese Patent Publication No. 60-58014). No. 4, JP-A-4-368837, etc.).
The overlay method is sometimes referred to as a vacuum laminating method, and the vacuum pressing method is sometimes referred to as a membrane pressing method because it uses not only the molding pressure but also the deformation pressure of a rubber-like elastic film such as a silicone rubber sheet.

[Vacuum press method]
Among them, the vacuum press method using the deformation pressure of the rubber-like elastic film in addition to the atmospheric pressure as the molding pressure is capable of suppressing the distortion of the molding sheet such as the molding laminate 10A that is locally extended. This is one of the preferred curved surface forming methods. Further, the vacuum press method is a curved surface forming method capable of degassing the space between the forming sheet and the forming die M before the forming sheet comes into contact with the mold surface of the forming die M. Therefore, it is a kind of preferable curved surface forming method from the viewpoint that deaeration can be performed to every corner of the forming surface. On the other hand, in the vacuum forming method performed by releasing the atmospheric pressure, the space between the forming sheet and the forming die M is degassed, and at the same time, the forming sheet contacts the mold surface of the forming die M. For this reason, in the vacuum press method, degassing can be performed by a method other than degassing through the vent hole of the mold M, and also in this respect, the trace of the vent hole can be made inconspicuous.
In the present embodiment, the curved surface molding is performed by a vacuum press method.

  Therefore, the vacuum pressing method will be described in detail with reference to the drawings. FIG. 3 is an explanatory view showing an example of a molding apparatus capable of performing a vacuum pressing method that can be used in the method of manufacturing a transmissive curved screen according to the present invention.

  Hereinafter, the molding laminate 10A will be referred to as a molding sheet 38 and described.

FIG. 3 is an explanatory view showing an example of a vacuum press apparatus 30 capable of carrying out one embodiment of the vacuum press method.
The vacuum press apparatus 30 of the figure includes a first chamber 31 that can move up and down at the top of the drawing, and a second chamber 32 that faces the first chamber 31 and below the drawing. An infrared heater 33 is provided inside the first chamber 31. The lower opening surface of the first chamber 31 is entirely covered with a rubber-like elastic film 34 made of silicone rubber or the like.
The upper surface of the second chamber 32 has a plurality of exhaust holes and serves as a mounting table 36 on which the mold M is mounted.
Each of the first chamber 31 and the second chamber 32 has an air supply / exhaust port 37 so that the pressure inside each chamber can be adjusted independently.

  In the vacuum press method, first, the molding sheet 38 is arranged on the molding die M installed on the mounting table 36 in a state where the first chamber 31 is moved upward and separated from the second chamber 32. FIG. 3A shows this state.

Next, the first chamber 31 is moved downward and pressed against the second chamber 32, and the first chamber 31 and the second chamber 32 are sealed.
Next, the pressure in the first chamber 31 and the second chamber 32 is reduced. Furthermore, the molding sheet 38 is heated and softened through the rubber-like elastic film 34 using the infrared heater 33 so as to be ready for molding.
Next, the inside of the first chamber 31 is pressurized while the inside of the second chamber 32 is kept under reduced pressure. As a result, the molding sheet 38 is pressed as a molding pressure by the atmospheric pressure due to the atmospheric pressure difference between the first chamber 31 and the second chamber 32 and the contraction pressure that is the deformation pressure of the rubber-like elastic film 34, and the molding die M The molding sheet 38 is curved into the shape of the mold surface of the mold M. FIG. 3B shows this state.

Finally, the decompression of the second chamber 32 is released, the pressurization of the first chamber 31 is released, both chambers are returned to atmospheric pressure, the first chamber 31 is moved upward, and the first chamber 31 and the second chamber 32 are moved. Then, the molding sheet 38 formed into a curved surface is taken out.
As a result, the curved laminated body 10 is obtained as the molding sheet 38 formed into a curved surface as shown in FIG.

  The above-described method described with reference to the molding apparatus shown in FIG. 3 is a form of the vacuum press method. In particular, when the molding sheet 38 starts to contact the mold surface of the mold M, the second chamber is already in the second chamber. In the case where the pressure is reduced and the space between the molding sheet 38 and the mold surface is deaerated, the contact point between the molding sheet 38 and the mold M is started in the vacuum molding method performed by releasing the atmospheric pressure. Is substantially different from the time when the deaeration starts. For this reason, in the vacuum press method, the trace of the vent hole of the mold M can be made less noticeable.

<< Hard coat layer forming process >>
In the present embodiment, after the molding laminate 10A is formed into a curved surface, it further includes a step of forming a hard coat layer as the surface layer 5 on the surface to be the light exit surface side Lout.
As a result, the curved laminate 10 or the transmissive curved screen 20 having the layer configuration shown in the cross-sectional view of FIG.
By forming a hard coat layer as the surface layer 5, it is possible to manufacture a transmissive curved screen 20 having excellent surface scratch resistance and fingerprint resistance.

  In the present invention, the hard coat layer may be formed at the stage of the molding laminate 10A. However, by forming the hard coat layer after the curved surface molding, the hard coat layer is produced while avoiding the occurrence of cracks during the curved molding of the hard coat layer. Because it can.

[Surface layer 5: Hard coat layer]
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 hard coat layer can be formed by a known coating method such as spray coating.
Although the thickness of a hard-coat layer respond | corresponds to a use and a requirement specification, it can be set as about 5-50 micrometers, for example.

  The hard coat layer can be formed of a known material. For example, the hard coat layer can be formed as a cured product layer of a transparent curable resin. As the curable resin, a thermosetting resin such as a urethane resin may be used, but it is preferable to use an ionizing radiation curable resin from the viewpoint of better scratch resistance and the like. 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 can be used. For example, acrylate-based prepolymers such as urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, and acrylic acrylate, multifunctional acrylate monomers, vinyl monomers. The resin composition which consists of 1 or more types of polymerizable compounds, such as these, can be used.
The 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.

<< B >> Second Embodiment In the second embodiment, as shown in FIG. 4, the curved Fresnel lens sheet 6 faces the light incident surface Lout on the light incident surface side Lin of the curved laminate 10. In this embodiment, the transmissive curved screen 20 is manufactured.

  Thus, by providing the curved Fresnel lens sheet 6 on the transmissive curved screen 20, the transmissive curved screen 20 having a high degree of freedom in the position of the image light source 41 (see FIG. 7 described later) for projecting image light is manufactured. Can do.

  The transmission curved screen 20 manufactured in the present embodiment has a configuration in which the curved Fresnel lens sheet 6 is a part of the constituent layers of the transmission curved screen 20 but is not closely integrated with the curved laminate 10. It is a layer.

The second embodiment is different from the first embodiment in the following points.
a) The transmission-type curved screen 20 includes the curved Fresnel lens sheet 6 on the light incident surface side Lin so as to be stacked separately from the curved laminate 10.
b) Separately from the first curved surface forming step for producing the curved laminated body 10, in order to produce the curved Fresnel lens sheet 6, a second curved surface forming step for shaping the curved Fresnel lens sheet 6A. A point that contains.
c) A point including a laminating step of laminating the curved laminate 10 and the curved Fresnel lens sheet 6.
d) The curved laminate 10 does not include a hard coat layer as the surface layer 5 and does not include a hard coat layer forming step. (For applications requiring a hard coat layer, of course, a hard coat layer forming step may be included as in the first embodiment, but this embodiment focuses on the above a), b) and c). It is. )

  Therefore, the second embodiment will be described below mainly on the points different from the first embodiment.

<< Laminated body preparation process >>
The molding laminate 10A prepared in the laminate preparation step is the same as that in the first embodiment, and has a layer configuration shown in FIG. Therefore, the further description regarding a laminated body preparation process is abbreviate | omitted.

<< First curved surface forming process >>
The first curved surface forming step is the same as that in the first embodiment. Therefore, the further description regarding a 1st curved surface shaping | molding process is abbreviate | omitted.

《Fresnel lens sheet preparation process》
The Fresnel lens sheet preparation step is a step of preparing a molding Fresnel lens sheet 6A before molding into a curved shape formed by the curved laminate 10.
In the present embodiment, a flat Fresnel lens sheet 6A is prepared.

[Fresnel lens sheet 6A for molding and curved Fresnel lens sheet 6]
The curved Fresnel lens sheet 6 is laminated so as to constitute a light incident surface side Lin layer of the transmissive curved screen 20.
The molding Fresnel lens sheet 6A preferably 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 the molding Fresnel lens sheet 6A, a sheet in which the Fresnel lens layer 7 is laminated on the transparent base material layer 3 as shown in FIG. 4 is used. Therefore, the curved Fresnel lens sheet 6 also has a configuration in which the Fresnel lens layer 7 is laminated on the transparent base material layer 3.

  In the case where further strength is required as the molding Fresnel lens sheet 6A, the reinforcing layer 8 is further laminated via the bonding layer 4 in the same manner as a modification to the molding laminate 10A described later with reference to FIG. In addition, a configuration with increased rigidity can be used.

(Transparent substrate layer 3)
The transparent base material layer 3 is a layer that also serves as a base material for forming the Fresnel lens layer 7. Since the transparent substrate layer 3 has already been described, the description thereof will be omitted.

  In the present invention, the transparent base material layer 3 is not essential for the Fresnel lens layer 7. The transparent base material layer 3 adjacent to the Fresnel lens layer 7 may be omitted, and the molding Fresnel lens sheet 6 </ b> A including only the Fresnel lens layer 7 or the curved Fresnel lens sheet 6 may be used.

(Fresnel lens layer 7)
The Fresnel lens layer 7 is a layer constituting a Fresnel lens by including a plurality of unit lenses. The Fresnel lens layer 7 converts image light incident from the light incident surface side Lin as a divergent light beam from the image light source 41 into a parallel light beam that travels toward the light output surface side Lout on the observer side of the transmissive curved screen 20. The Fresnel lens layer 7 converts the image light into a light beam substantially perpendicular to the screen surface, thereby suppressing unevenness in image brightness.
The Fresnel lens layer 7 may be a circular Fresnel lens in which unit lenses are arranged concentrically or arcuately according to the positional relationship between the transmissive curved screen 20 and the image light source 41, or linearly extending unit lenses are parallel to each other. An array of linear Fresnel lenses may be used.

The Fresnel lens layer 7 may be made of a known material and a forming method.
The Fresnel lens layer 7 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 7 is not particularly limited. For example, the Fresnel lens layer 7 can be formed by forming a unit lens on the transparent base material layer 3 by the photopolymer method (2P method) in the same manner as the light transmitting portion 2b described above. For example, when an acrylate ionizing radiation curable resin is used to form the photopolymer method, the Fresnel lens layer 7 made of an acrylic resin is formed.

<< Second curved surface forming step >>
In the second curved surface molding step, the curved Fresnel lens sheet 6A prepared in the Fresnel lens sheet preparation step is curved using a molding die M to form a curved surface having the same curved surface shape as that of the curved laminated body 10. This is a process for forming the Fresnel lens sheet 6.
In the present embodiment, the curved surface shape is a three-dimensional curved surface.
In the second curved surface molding step, curved surface molding is performed using the molding Fresnel lens sheet 6A instead of the molding laminate 10A in the first curved surface molding step. Therefore, detailed description is omitted here.
In the present embodiment, the curved surface forming in the second curved surface forming step is also performed by a vacuum press method. In the vacuum press method, the molding laminate 10A to be the molding sheet 38 is changed to the molding Fresnel lens sheet 6A in the description of the first curved surface molding step with reference to FIG.

  In the present embodiment, the molding Fresnel lens sheet 6A is bent so that the lens surface of the Fresnel lens layer 7 is the light exit surface side Lout and the convex side of the curved surface. For this reason, curved surface molding is performed in such a manner that the transparent base material layer 3 side comes into contact with the convex curved mold surface of the molding die. For this reason, in this embodiment, as in the first curved surface forming step in the second embodiment, the center portion can be less stretched and deformed compared to the case where the concavities and convexities are reversed, and the transmission type manufactured. Molding can be performed without greatly affecting the brightness and viewing angle of the image at the center of the curved screen 20.

<< Lamination process >>
The laminating step is a step of laminating the curved laminate 10 obtained in the first curved surface forming step and the curved Fresnel lens sheet 6 obtained in the second curved surface forming step. Through the laminating step, a transmissive curved screen 20 having a curved shape in which the curved laminate 10 and the curved Fresnel lens sheet 6 are laminated is produced.

The curved laminated body 10 and the curved Fresnel lens sheet 6 may be cut into appropriate sizes and shapes before being laminated.
In addition, the plan view shape when finally becoming the transmissive curved screen 20 is a shape according to the installation part of the device in which the transmissive curved screen 20 is incorporated, and may be any shape such as a rectangle, a circle, an ellipse, etc. is there.

In the present embodiment, the curved Fresnel lens sheet 6 and the curved laminate 10 are laminated with the Fresnel lens layer 7 of the curved Fresnel lens sheet 6 on the curved laminate 10 side.
However, since the Fresnel lens layer 7 may rub against the curved laminate 10 and damage the curved laminate 10, a slip agent such as silicone oil is applied to the surface of the curved laminate 10 that contacts the Fresnel lens layer 7. It is preferable to apply it.
Further, if the gap between the Fresnel lens layer 7 and the curved laminate 10 becomes large, a ghost (double image) may occur in the transmissive curved screen 20, and thus the curved laminate 10 and the Fresnel lens layer 7. It is preferable to make it contact.
The method of laminating the curved laminated body 10 and the curved Fresnel lens sheet 6 is not particularly limited. For example, the curved Fresnel lens sheet 6 and the curved laminated body 10 are stacked, and their peripheral portions are sandwiched and fixed by metal clips. The method of doing is mentioned.

  In this invention, when it has a 2nd curved surface shaping | molding process, the lens surface of the Fresnel lens layer 7 of the curved surface Fresnel lens sheet 6 may face the light-incidence surface side Lin. In this case, the curved laminate 10 and the curved Fresnel lens sheet 6 that are separately curved may be adhered and laminated. However, when the lens surface of the Fresnel lens layer 7 of the curved Fresnel lens sheet 6 is set as the light output surface side Lout as in the present embodiment, it is not possible to stack the layers closely, and thus the lamination of the curved laminate 10 and the curved Fresnel lens sheet 6. Is a structure in which the curved laminate 10 and the curved Fresnel lens sheet 6 are superposed.

In the present embodiment as described above, the curved laminate 10 and the curved Fresnel lens sheet 6 are separately curved and molded, so that the transmissive curved surface having a configuration in which the lens surface of the Fresnel lens layer 7 is the light exit surface Lout. The screen 20 can be manufactured with less noticeable traces of the vents of the mold.
Moreover, it becomes possible to prepare the curved Fresnel lens sheet 6 and the curved laminated body 10 separately. For example, the curved Fresnel lens sheet 6 can be prepared in accordance with the position of the image light source 41 (see FIG. 7 described later), and the curved laminated body 10 can be prepared in accordance with the required image quality. These can be combined according to the specifications.
In addition, the curved surface Fresnel lens sheet 6 and the curved surface laminate 10 can be separately molded during curved surface molding. In the curved surface molding of the curved Fresnel lens sheet 6, it is preferable to mold the Fresnel lens layer 7 in such a direction that it does not come into contact with the mold surface of the mold, so that the degree of molding freedom can be increased.

<< C >> Modifications In the present invention, the transmissive curved screen 20 adopts other layer configurations or processes in a conventionally known transmissive screen as appropriate, in addition to the layer configurations and processes described in the above embodiment. Can do. For example, in the layer configuration, the reinforcing layer 8, the Fresnel lens layer 7 tightly integrated with the curved laminate 10, an antireflection layer, an antistatic layer, a colored layer, and the like.
Hereinafter, the reinforcing layer 8 and the Fresnel lens layer 7 which is closely integrated will be described.

[Reinforcing layer 8]
In the present invention, the molding laminate 10A, the curved laminate 10, the molding Fresnel lens sheet 6A, the curved Fresnel lens sheet 6 and the transmissive curved screen 20 can have the reinforcing layer 8.
For example, the molding laminate 10A, the curved laminate 10 or the transmissive curved screen 20 of the modified form shown in FIG. 5 is further reinforced with respect to the configuration of FIG. 2A shown as the molding laminate 10A. In this embodiment, the layer 8 and the bonding layer 4 for laminating the reinforcing layer 8 are provided. The reinforcing layer 8 is laminated so as to constitute a layer on the light incident surface side Lin of the molding laminate 10A, the curved laminate 10 or the transmissive curved screen 20. Since the bonding layer 4 has already been described, the reinforcing layer 8 will be described here.

The reinforcing layer 8 increases the rigidity of the molding laminate 10A, the curved laminate 10, the molding Fresnel lens sheet 6A, the curved Fresnel lens sheet 6 or the transmissive curved screen 20, and is deformed unintentionally during the manufacturing process. This can be prevented when the handling and quality are disturbed.
The material of the reinforcing layer 8 is a transparent resin such as a polycarbonate resin (PC resin), methyl methacrylate-butadiene-styrene copolymer (MBS resin), methyl methacrylate-styrene copolymer (MS resin), or the like. An acrylic resin can be used.
The thickness of the reinforcement layer 8 can be 3-5 mm, for example. If the thickness is too thick, the transmittance of the image light may decrease, or a ghost (double image) may occur, resulting in a decrease in optical performance.

  In order to manufacture the molding laminate 10A, the curved laminate 10 or the transmissive curved screen 20 having the configuration of FIG. 5, for example, in the molding laminate 10A according to the manufacturing method described in the first embodiment, the light beam The control layer 2 can be manufactured by bonding and laminating the reinforcing layer 8 via the bonding layer 4 to the transparent base material layer 3 used as a base material at the time of creation.

[Fresnel lens layer 7 integrated in close contact]
In the present invention, in the molding laminate 10A, the curved laminate 10, and the transmissive curved screen 20, the Fresnel lens layer 7 can be a close-integrated layer.
For example, the molding laminate 10A, the curved laminate 10 and the transmissive curved screen 20 of the modified form shown in FIG. 6 are further added to the configuration of FIG. 2A shown as the molding laminate 10A in addition to the Fresnel lens. It is the structure by which the layer 7 was closely integrated. Specifically, the Fresnel lens layer 7 is in close contact with the transparent base layer 3 through the bonding layer 4 as a molding Fresnel lens sheet 6A before molding and as a curved Fresnel lens sheet 6 after curved molding. It is an integrated configuration.
When FIG. 6 shows a molding laminate 10A, in terms of shape, the curved Fresnel lens sheet 6 in FIG. 6 becomes the molding Fresnel lens sheet 6A.
Since the Fresnel lens layer 7, the transparent base material layer 3, and the bonding layer 4 have already been described, matters related to the curved Fresnel lens sheet 6 will be described here.

  In the case where the Fresnel lens layer 7 is included in the molding laminate 10A, the lens surface of the Fresnel lens layer 7 is laminated in such a direction that the lens surface becomes the light incident surface Lin as shown in FIG. The

  In the first curved surface molding process of forming the molding laminate 10A into a curved surface, the Fresnel lens layer 7 is placed on the side of the Fresnel lens layer 7 so that the lens does not deform when the Fresnel lens layer 7 comes into contact with the mold surface of the molding die M during curved surface molding. The surface to be the light surface side Lin is preferably molded in a form that does not contact the mold surface. That is, the molding laminate 10A is curved-shaped so that the light exit surface side Lout is in contact with the mold surface of the mold M.

  In order to manufacture the molding laminate 10A, the curved laminate 10 and the transmissive curved screen 20 having the configuration shown in FIG. 6, for example, as the molding laminate 10A to be used, the molding laminate having the configuration shown in FIG. It can be manufactured by using a laminate obtained by bonding and laminating a molding Fresnel lens sheet 6A via a bonding layer 4 to the laminate 10A.

  With such a configuration, the transmissive curved screen 20 with the Fresnel lens layer 7 can be manufactured without the second curved surface molding step.

<< D >> Display Device Next, a display device provided with the transmissive curved screen 20 obtained by the manufacturing method according to the present invention described above will be described.

FIG. 7 is a cross-sectional view schematically showing an example of the display device 100. FIG. 7A shows the display device 100.
The display device 100 shown in the figure includes a transmissive curved surface screen 20 obtained by the manufacturing method described above. More specifically, the display device 100 includes the above-described transmissive curved screen 20 according to the present invention, an image light source 41, and a housing 42 that stores these and fixes them in a predetermined positional relationship. .
With the display device 100 having such a configuration, it is possible to provide a device in which the traces of the vent holes of the mold M are less noticeable when the transmissive curved screen 20 is manufactured.

[Transparent curved screen 20]
Since the transmissive curved screen 20 has already been described, further description is omitted here.

[Video light source 41]
The image light source 41 is not particularly limited as long as the image light Lv can be projected onto the transmissive curved screen 20. For example, the image light source 41 is a liquid crystal display device (LCD), an EL (electroluminescence) display device, a digital micromirror device (DMD), or the like.

[Case 42]
The housing 42 can be made of a material according to the application such as resin or metal. In the present invention, the housing 42 can be omitted. For example, it is a case where components other than the housing | casing 42 are assembled | attached in the dashboard of a motor vehicle. However, the provision of the housing 42 can improve maintenance such as parts replacement.

DESCRIPTION OF SYMBOLS 1 Light diffusion layer 2 Light control layer 2a Light absorption part 2b Light transmission part 3 Transparent base material layer 4 Joining layers (adhesion layer, adhesion layer, etc.)
5 Surface layer (hard coat layer, etc.)
6 Curved Fresnel Lens Sheet 6A Molding Fresnel Lens Sheet 7 Fresnel Lens Layer 8 Reinforcing Layer 10 Curved Laminate 10A Molding Laminate 20 Transmission Curved Screen 30 Vacuum Press Device 31 First Chamber 32 Second Chamber 33 Infrared Heater 34 Rubber Elastic film 36 Mounting table 37 Air supply / exhaust port 38 Molding sheet 41 Video light source 42 Housing 51 Molding sheet 52 Fixed frame 53 Infrared heater 54 Molding die 55 Cutter 100 Display device Lin Light incident surface side Lout Light emitting surface side Lv Video light M Mold

Claims (4)

A transmissive curved screen that includes a curved surface laminate having a curved surface shape and transmits image light incident from the light incident surface side to the light exit surface side,
The curved laminate includes, in order from the light exit surface side, at least a light diffusion layer and a light control layer. The light control layer includes a light absorbing portion arranged along the layer surface so as to be able to absorb light, and the light. A light-transmitting curved screen having a light-transmitting portion arranged so that light can be transmitted between the absorbing portions,
Preparing a laminate for molding before molding into the curved surface shape, a laminate preparation step,
A first curved surface forming step in which the molded laminate is formed into a curved surface by forming a curved surface using a mold and atmospheric pressure;
Including
By the first curved surface forming step, the mold have a plurality of vent holes in the mold surface by the mold material itself is a porous material, and the molding mold surface has a convex curved surface,
A method of manufacturing a transmissive curved screen.   2. The method of manufacturing a transmissive curved screen according to claim 1, wherein the molding laminate includes a Fresnel lens layer having a lens surface facing the light incident surface side on the light incident surface side. A Fresnel lens sheet preparation step, having a Fresnel lens layer, preparing a Fresnel lens sheet for molding before molding into the curved shape formed by the curved laminate,
A second curved surface molding step, wherein the molding Fresnel lens sheet is formed into a curved surface using a molding die to form a curved Fresnel lens sheet having the curved surface shape;
Laminating the curved Fresnel lens sheet on the light incident surface side of the curved laminate, and a laminating step;
Including
In the second curved surface molding step, the mold has a plurality of ventilation holes on the mold surface because the mold material itself is a porous material.
The manufacturing method of the transmission type curved screen of Claim 1. The manufacturing method of the transmissive | pervious curved screen of any one of Claims 1-3 whose hole diameter of the said vent hole is 10-30 micrometers.

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