JPH05224303A - Production of reflection-type screen - Google Patents

Abstract

PURPOSE:To industrially and advantageously produce the screen having a desired optical characteristic with good productivity by printing an ionizing radiation curing resin on a supporting sheet with the use of a roll intaglio to form fine ruggednesses on the screen surface. CONSTITUTION:A roll intaglio 5 having a leticular fine ruggedness on the surface is rotated, an ionizing radiation curing liq. resin 13 is filled in the recessed part of the intaglio 5, and a transparent and soft plastic supporting sheet 11 is traveled by the rotating intaglio 5 and pressed on the intaglio 5. The resin 13 is irradiated with ionizing radiation and cured, the cured resin layer 12 is adhered to the sheet 11, then the sheet 11 is separated from the intaglio 12 along with the resin layer 12 to form the resin layer 12 having a leticular fine ruggedness on one side of the sheet 11, and a leticular sheet 1 is formed. The non-leticular side of the sheet 1 is then backed with a light diffusing and reflecting base sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a reflection type screen for projecting moving images such as movies and televisions.

[0002]

2. Description of the Related Art With the spread of liquid crystal projectors,
A screen capable of displaying high-quality images on a large screen with high brightness has been demanded.
To address this, the applicant has already developed and proposed the following screen (Japanese Patent Application No. 3-19676).
3). One of them is a white opaque flexible plastic base sheet on a glass fiber base cloth with a light absorption layer on the back surface, and a translucent flexible plastic light that is made by kneading a luster pigment or calcite powder. It is a screen with a diffusion layer provided in order and embossed on the surface. Another is a white opaque flexible plastic base sheet with a light absorption layer on the back surface, and a semi-finished mixture of luster pigment or calcite powder. It is a screen in which a transparent and flexible plastic light diffusion layer is sequentially provided and the surface is embossed.

A screen of this type is, for example, in Shokai Sho 6
It is manufactured by the method disclosed in JP-A-2-164329. That is, after laminating the base cloth, the base sheet and the light diffusing layer respectively, by a method of embossing the surface of the light diffusing layer, or at the same time as laminating the base cloth, the base sheet and the light diffusing layer, This is a method of embossing the surface of the light diffusing layer.

However, it is difficult to form fine irregularities having an accurate lens shape by the embossing method. If embossing is performed with sufficient heat and time, the concavo-convex shape will be somewhat accurate, but it is still difficult to give satisfactory optical characteristics, and productivity is low, so it cannot be said to be a practical manufacturing method.

As another method for producing a screen, there is known a method in which a highly reflective film and a light diffusing film are laminated and integrated on a molded article having a Fresnel concave surface by a vacuum molding method (Japanese Patent Laid-Open No. 53-123926). Publication). This method is difficult to apply to the production of large screens, and, unlike the above-mentioned production method, only fixed screens can be produced, and roll-up screens cannot be produced.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method capable of producing a reflective screen having desired optical characteristics with productivity which is advantageous for industrial implementation.

[0007]

The method of manufacturing a reflection type screen of the present invention comprises the following steps: 1A) As shown in FIG. 1, a roll intaglio plate (5) having lens-like fine irregularities on its surface is used. ) Is rotated so that the ionizing radiation curable resin liquid (1
3) is filled and a transparent and flexible plastic support sheet (11) running in synchronization with the direction of rotation of the roll intaglio is pressed against the roll intaglio, or 1B) as shown in FIG. A flexible plastic support sheet (11) coated with an ionizing radiation-curable resin liquid (13) is pressed against (5) so that the coated surface contacts the roll intaglio plate, and 2) the roll intaglio plate is used as the support sheet. While rotating so as not to come off, the ionizing radiation is applied to cure the ionizing radiation curable resin liquid, and at the same time, the curable resin layer (12) and the support sheet (11) are adhered to each other, and 3) the support sheet is cured resin. A lens sheet (1) having a lens-like fine concavo-convex cured resin layer (12) formed on one surface of a support sheet (11) is produced by separating the roll sheet and the layer from a roll intaglio plate. And, 4) the non-lens surface of the lens sheet, as shown in FIG. 3, by laminating a light diffuse reflective backing substrate sheet (2).

1 and 2, (6), (7),
(8) is a pressure roll, a feed roll, and an ionizing radiation irradiation means, respectively, and (9) in FIG. 2 is a coating means.

In order to fill the concave portion of the roll intaglio with the ionizing radiation-curable resin liquid, as shown in FIG. 1, the resin is supplied to the place where the supporting sheet is pressed against the roll intaglio, and the roll intaglio is rotated and the resin is supplied. The recess may be filled with resin. A more preferable method is to fill the concave portion of the roll intaglio with the resin using a T-die type nozzle coating device or the like, which is easier to prevent bubbles from being mixed into the resin layer.

The most preferable manufacturing apparatus has the structure shown in FIG. This device will be described with reference to FIG. 5A. The roll intaglio plate (5) is a cylindrical plate material provided with lens-shaped recesses. The recesses can be manufactured by a method of directly lathing a cylindrical plate material, a method of cutting by milling with a mill formed by electroforming, or an electroforming method. As the material of the roll intaglio, a metal such as copper, chromium, iron or the like, a synthetic resin such as NBR, epoxy or ebonite, or a ceramic such as glass can be used.
The size of the roll intaglio plate is not particularly limited and can be appropriately selected according to the size of the screen to be manufactured. Although not shown, the roll intaglio is provided with a drive device and is configured to be rotationally driven.

In order to adjust the viscosity of the resin liquid (13) to a predetermined value, as shown in (A to D) of the roll intaglio shown in FIG. 6, the inside is hollow and the hollow portion has an appropriate temperature. Water of,
A method of controlling the plate surface temperature to an appropriate value by inflowing / outflowing a fluid serving as a heat medium such as oil or steam can be used. The temperature of the resin liquid generally decreases as the temperature rises. However, if the temperature is too high, decomposition or evaporation of the resin liquid occurs.

Various modes shown in FIG. 6 are possible for inflowing and outflowing the fluid. That is, as in (A), a method of flowing a fluid from one side to the other side of the rotating shaft (5a) of the roll intaglio (5A), and as in (B), the roll intaglio (5a).
A method in which the feed pipe (5b) is inserted into the inside of B), and the fluid sent to the inside of the roll intaglio by the feed pipe is returned along the inner wall of the roll intaglio, as in (C), the inside of the roll intaglio (5C) In addition, an inner tube (5C) having a shape substantially similar to this is provided, and a fluid is passed between the roll intaglio and the inner tube. As shown in (D), the inside of the roll intaglio (5D) is shown in (E). Open hole (5e)
A method in which a feed pipe (5d) provided with a large number of is inserted and the fluid jetted from the opening of the feed pipe is returned along the inner wall of the roll intaglio plate.

The best way to uniformly control the temperature of the plate surface is the embodiment shown in FIG. 6 (D).

Returning to FIG. 5A, the pressure roll (6)
Is for pressing the base material sheet (11), and is usually about 140 mm in diameter, and is made of silicone rubber, NBR, E
It can be formed of PT or the like. The pressure roll (6) and the feed roll (7) may be of a type in which they roll around with the roll intaglio plate (5), but are preferably driven by a driving device.

An additional irradiation device (8b) may be provided in order to completely cure the ionizing radiation-curable resin liquid by the ionizing radiation irradiation device (8a).

As a means for applying the ionizing radiation-curable resin liquid (13) to the roll intaglio plate (5), it is desirable to use the nozzle coating device shown in FIG. 5 (A). In this nozzle coating device, a T-die-shaped nozzle has a rectangular or linear discharge port of a predetermined size, and is provided so as to cover a predetermined width of the entire width of the roll intaglio plate. It is provided with a pressurizing means for pressurizing the radiation-curable resin liquid and ejecting it onto the roll intaglio 1 in a curten shape.

Although not shown, the ionizing radiation-curable resin liquid was coated on the base sheet without coating the roll intaglio plate, and then the roll intaglio plate was coated with a pressing roll. It is also possible to obtain the same effect as above by pressing the coating film surface on the material sheet 4. In order to faithfully reproduce fine irregularities without inclusion of air bubbles, it is preferable to apply a resin liquid on the roll intaglio side.

The ionizing radiation irradiation device may be one as shown in FIG. 5 (A), but as shown in FIG. 5 (B), a plurality (8a-1 to 8a-5 in this embodiment) may be provided. 5) may be provided to cure the resin liquid in the roll intaglio in multiple stages. By doing so, a sufficient irradiation amount can be obtained even if the strike speed of the base sheet is increased, and by gradually hardening, distortion of the cured product of the resin liquid and the base sheet This is preferable because curling and distortion can be reduced.

The ionizing radiation curable resin used here is
It should be selected from the known ones, but the viscosity is 5000
Those of cps or less, especially those of about 1000 cps are preferable because they are well spread over the concave portions of the roll intaglio. The viscosity of the resin can be adjusted by selecting an appropriate monomer, oligomer, or prepolymer and by changing the temperature of the roll intaglio. It is desirable to use the ionizing radiation curable resin liquid without diluting it with a solvent. This is because the resin containing no solvent has almost no volume shrinkage or shape change upon curing, and the uneven shape of the plate can be accurately reproduced on the support sheet.

The side of the ionizing radiation curable resin is a monomer, an oligomer or a prepolymer having an ethylenically unsaturated bond or an epoxy group or a thiol group in the molecule, and specifically, it is a urethane (meth) acrylate. -, (Meth) acrylates such as polyester (meth) acrylate, and unsaturated polyesters, and in the case of curing with light or ultraviolet rays, a known photoreaction initiator may be added.

In the embodiment shown in FIG. 2, the ionizing radiation curable resin may be applied to the support sheet by using a known application means such as a roll coater or a knife coater.
In this case, it is difficult to carry out by any coating means unless the resin is diluted with the solvent.Therefore, the solvent is diffused from the coating by heating before pressing the support sheet against the roll intaglio plate. Preferably. If necessary, the coating film can be semi-cured by irradiation with ionizing radiation to adjust the viscosity.

The means for irradiating the ionizing radiation includes an ultraviolet lamp such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp,
Carbon arc, black light lamps, and metal halide lamps are preferable because they are easy to operate. Various electron beam accelerators, for example, Cockloft-Walton type, Van de Graaff type, resonance transformer type, insulating core transformer type, linear type, dynamitron type, and high frequency type electron beam accelerators may be used.

When a material that does not easily transmit ultraviolet rays is used as the material of the support sheet, for example, when a plastic sheet in which a bright pigment as described below is kneaded is used, the above electron beam accelerator is used, or The roll intaglio plate may be made of a material such as quartz or glass that transmits ionizing radiation, and the ionizing radiation may be irradiated from the inside of the roll intaglio plate.

The plastic used as the material for the transparent support sheet and the base sheet may be any plastic so long as the support sheet is required to have transparency to visible light, but the base sheet is opaque. Can be used.
Polyvinyl chloride is a typical material, and 10 to 60 parts of plasticizer are added to 100 parts by weight of polyvinyl chloride.
A semi-hard to soft material added with about parts by weight is suitable. In addition, polypropylene, polyethylene, polyethylene terephthalate, polycarbonate and the like can be preferably used. It is suitable that the thickness of the support sheet is in the range of 25 to 200 mm, and the thickness of the base material sheet is in the range of 50 to 200 mm.

In order to obtain a high reflectance and an appropriate half-value angle, 0.5 to 10% by weight of the glittering heat agent described below is contained in the supporting sheet.
It can be added to some extent.

The cured resin layer, that is, the fine irregularities on the support sheet may be formed so that the shape of the concave portions or convex portions is a quadric surface or a cubic curved surface. Specifically, for example, (a part of) a spherical surface, an elliptic surface, a paraboloid of revolution, a cone or a truncated cone, a pyramid or a truncated pyramid, or a so-called fly-eye lens type in which micro concave mirror groups are distributed over the entire surface, or A group of concave mirrors in the shape of a cylinder, a parabolic cylinder, an elliptic cylinder, or those half-cut in the symmetry axis direction are distributed over the entire surface so that the vertical direction is the axial direction, that is, a lenticular reflection concave mirror. There is.

Of these, if it is desired to diffuse light in all directions in the vertical, horizontal, and diagonal directions so that the light can be seen with the same brightness from the visual field in all directions, the former spherical concave mirror group is preferably used. In addition, when a wide field of view in the vertical direction is not needed for ordinary viewing, etc., but rather a wide field of view in the horizontal direction, the latter group of lenticular concave mirrors efficiently requires a limited amount of light (front left and right). It is preferable because it can diffuse only in the direction). Normally, the half value angle of light diffusion in the horizontal plane (left-right direction) (the angle at which the reflectance at a tilted angle attenuates to 1/2 of the reflectance in the direction perpendicular to the screen) is 20 °.
Above, preferably about 60 ° is necessary.

The surface shape of the cured resin layer is constituted by an embossed pattern which is commonly used in conventional reflection type screens, for example, a pattern in which corrugations intersect at 90 °, a grain pattern or a hairline pattern. can do.

The backing base sheet is constructed by laminating a light diffusion layer, a light reflection layer, a black or white opaque base sheet, a base cloth and a light absorbing layer in this order from the side close to the support sheet. Is. One or both of the light-diffusing layer and the light-reflecting layer may be omitted when particularly large reflectance and narrow light-diffusion half-value angle are not required.

In order to obtain a white and opaque base sheet, the plastic for the base sheet may be kneaded with a white pigment such as TiO ₂ fine powder to form a film. A black resin sheet may be used instead, depending on the desired amount of reflection.

The base cloth is for increasing the dimensional stability of the screen, and especially when it is used as a roll-up screen, it is required to have a function of preventing the drawn screen from sagging. Also, when rewinding the screen that was rolled up and stored and used again for projection,
Since the image is distorted when the curl remains, the base fabric is required to have sufficient elastic recovery and rigidity. A glass fiber woven or non-woven fabric satisfies these requirements.

When the light absorbing layer is provided on the glass fiber base cloth, a dark color, for example, black, black brown or dark blue pigment is kneaded into the same plastic as the material of the base sheet, and the formed sheet is laminated on the base cloth. Good. It is preferable that the thickness of this sheet be approximately the same as the total thickness of the base sheet and the support sheet so that the screen is well balanced in the thickness direction.

When the light absorbing layer is provided on the base sheet, the base sheet may be solid-printed with a dark ink. Printing can follow known means.

The lens sheet, base sheet and base cloth are
The three may be laminated at the same time, or the backing sheet may be formed by first laminating the base material sheet and the base fabric, and then laminating the laminated body and the lens sheet, and the order is arbitrary. ..
The lamination is appropriately selected from known methods such as a dry lamination method and a heat fusion method.

When it is required as the optical characteristics of the screen that a clear image can be seen even in a bright place where light such as sunlight or electric light is applied to the screen, the lens sheet and the base cloth or the base sheet are combined. Either or both of the light diffusion layer and the light reflection layer may be provided between them. The light-diffusing layer is a mixture of bright pigment or calcite powder,
It is a translucent and flexible plastic sheet. The plastic used for the light diffusion layer may be the same as the plastic used for the base sheet or the support sheet.

Examples of the bright pigment are as follows. (A) What is called a pearl pigment, specifically, the inside part of shellfish and pearls are crushed, mica, mica fine particles baked with TiO ₂ or iron oxide,
(B) Metal powder, specifically copper, aluminum, brass, bronze, gold, silver, etc., preferably 1 to 120 μm fine particles; (c) Fragments of vapor deposited plastic film, such as polyethylene terephthalate film. A metal like this, usually aluminum, deposited and crushed. These bright pigments preferably have a scaly shape. When the surface of the scale-like body is arranged in parallel with the surface of the base material sheet, diffuse reflection with high brightness can be achieved.

The calcite powder has an average particle size of 2 to 20 μm.
It is preferable that the particle size distribution is as narrow as possible, and the particle size distribution is preferably as narrow as possible. For example, if the average particle size is 5 μm, 80
The particle size distribution is such that weight% or more falls within the range of 3 to 7 μm.

The amount of the bright pigment or calcite powder added to the plastic for the light diffusion layer is preferably 0.5 to 10% by weight, and more preferably about 2% by weight.

The thickness of the light diffusing layer is preferably in the range of 0.04 to 0.8 mm in consideration of keeping the image bright by suppressing the attenuation of the reflected light when the reflecting layer is not provided. Is. When the reflective layer is provided, the amount of reflected light is less attenuated. Therefore, the range of 0.05 to 1 mm is suitable from the viewpoint of increasing the half-value angle by thickening the light diffusion layer.

The light diffusion layer may be laminated in the same manner as the lamination of other sheets. It is also possible to use the support sheet in which the bright pigment or the calcite powder is dispersed as the support sheet to form the light diffusion layer.

The light-reflecting layer is formed by solid-printing an ink containing a glittering pigment or calcite powder on the light-diffusing layer or the base sheet before laminating the sheets.

The ink used for printing the light reflecting layer is an ink in which a bright pigment or calcite powder is dispersed in an ordinary ink vehicle, and examples of the vehicle are polyvinyl chloride and vinyl chloride vinyl chloride copolymer. , Acrylic resin, polyurethane, polyester and the like. It is preferable that the ratio of the brilliant pigment in the ink is high, but if the ratio of the vehicle is too low, it becomes difficult to form a printed layer on the base sheet, so the ink composition is 5 to 50 parts of the vehicle per 100 parts by weight of the pigment.
Parts by weight are preferred. The thickness applied by printing is usually about 1 to 10 μm.

Since the ink in which the coarse-grained bright pigment of this kind is dispersed easily causes unevenness at the time of printing, the ink is not printed to a desired thickness at one time, but is printed to a fraction of the thickness. It is preferable to perform overprinting in which the above steps are repeated several times so that all layers have a desired thickness, because the light diffusing layer has high reflection performance.

When the calcite powder is used, the composition of the ink is preferably 10 to 100 parts by weight, and more preferably 10 to 50 parts by weight for 100 parts by weight of the calcite powder for the same reason as above.

Printing may be performed by known methods such as printing methods such as gravure method and silk screen method and coating methods such as spray coating and roll coating. The thickness of the printing layer is 1 μm in a dry state. The above is enough.

[0046]

In the present invention, as a means for forming fine irregularities on the screen surface, a method of printing an ionizing radiation curable resin on a supporting sheet by printing using a roll intaglio is adopted instead of the conventional embossing method. According to this method, the uneven shape is formed with the fluid uncured resin, and it is cured in a state of being regulated by the intaglio plate, so that it is possible to form fine unevenness on the screen surface in which the shape of the intaglio plate is accurately reproduced. A reflective screen having desired optical properties can be manufactured.

According to the manufacturing method of the present invention, since the lens sheet can be manufactured continuously, the productivity is higher than the method of embossing each screen.

[0048]

[Examples] A roll intaglio made of copper was prepared by forming an uneven shape opposite to the shape of a lenticular lens by electroforming and plating the surface with chrome. As shown in FIG. 5, a nozzle coating device that fills the concave portion of the roll intaglio with the ionizing radiation curable resin liquid, a pressing roll that presses the support sheet against the roll intaglio plate, and a feed roll that removes the support sheet from the roll intaglio plate, Between the pressing roll and the feed roll, as the ionizing radiation irradiating means, five two-lamp ozone generation type high pressure mercury lamps (intensity 120 W / cm) were provided along the rotation direction of the roll intaglio plate.

A colorless and transparent biaxially stretched polyethylene terephthalate sheet having a thickness of 25 μm is used as a supporting sheet, and an ultraviolet curable resin liquid containing a polyester acrylate polyfunctional monomer as a main component (solventless type, viscosity 1000 cps). ) Was applied using the above-mentioned device to produce a lens sheet having a lenticular lens-shaped cured resin layer formed thereon.

A 0.2 mm thick black polyvinyl chloride sheet (DOP: 60 ph) is used as a light absorbing layer provided on the back surface of the base cloth.
r) was used, and a woven glass fiber fabric was used as the base fabric.
A white polyvinyl chloride sheet (DOP: 60 phr) having a thickness of 0.13 mm is used as the base sheet, and 2% by weight of a pearl pigment (titanium-coated mica) is added to the polyvinyl chloride (DOP: 60 phr) as a light diffusion layer. A 0.12 mm-thick semitransparent sheet obtained by kneading and extruding was used.

A base cloth, a base material sheet and a light diffusing layer were laminated in this order on the light absorbing layer and integrated by a heat and pressure doubling method using a mirror plate laminate roll.

On the light diffusion layer of this laminate, the lens sheet was laminated by a dry lamination method using a two-component curing type polyurethane adhesive, cut into a predetermined size, and the reflection type of the present invention. Got the screen.

[0053]

According to the method of the present invention, a reflection type screen having desired optical characteristics can be manufactured. This manufacturing method has higher productivity than the conventional embossing manufacturing method, and is therefore advantageous in terms of cost.

[Brief description of drawings]

FIG. 1 is a conceptual diagram for explaining one aspect of manufacturing a lens sheet in a manufacturing method of the present invention.

FIG. 2 is a similar view for explaining another mode of manufacturing the lens sheet in the manufacturing method of the present invention, which is different from FIG.

FIG. 3 is a schematic cross-sectional view for explaining one aspect of the laminating step in the manufacturing method of the present invention.

FIG. 4 shows a stacking process in FIG. 3 in the manufacturing method of the present invention.
FIG. 6 is a diagram for explaining an example in which another mode is adopted.

FIG. 5A is a similar view for explaining another mode of manufacturing the lens sheet in the manufacturing method of the present invention, which is different from FIGS. 1 and 2. 3B is a partially enlarged view showing a further modification of A. FIG.

6A, 6B, 6C, and 6D are longitudinal sectional views showing various aspects of the internal structure of the intaglio roll shown in FIG. 5A.
E is a perspective view showing the appearance by taking out a part of the structure shown in D.

[Explanation of symbols]

 1 Lens Sheet 11 Support Sheet 12 Curing Resin Layer 13 Ionizing Radiation Curing Resin Liquid 2 Base Material Sheet 3 Base Fabric 4 Light Absorbing Layer 5 Roll Intaglio 6 Pressing Roll 7 Feeding Roll 8 Ionizing Radiation Irradiating Means 9 Coating Means

Claims (1)

[Claims] 1. A method for producing a reflection type screen comprising the following steps: 1A) A roll intaglio having a lens-like fine concavo-convex shape on its surface is rotated, and at least recesses of the roll intaglio are filled with an ionizing radiation curable resin liquid. Then, a transparent and flexible plastic support sheet that runs in synchronization with the direction of rotation of the roll intaglio is pressed against this roll intaglio, or 1B) a roll intaglio coated with an ionizing radiation-curable resin liquid. Press the transparent and flexible plastic support sheet that runs in synchronization with the direction of rotation so that the coated surface hits the roll intaglio, and 2) rotate the roll intaglio synchronously so that the support sheet does not come off the roll intaglio. Irradiating ionizing radiation to cure the ionizing radiation-curable resin liquid, and at the same time, to bond the cured resin layer and the support sheet, By separating the support sheet together with the cured resin layer from the roll intaglio, a lens sheet having a lens-like fine unevenness cured resin layer formed on one surface of the support sheet is produced, and 4) on the non-lens surface of this lens sheet, Laminating a light diffusive reflective backing substrate sheet.