JPS63221333A - Composite material and screen made thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to composite materials with excellent reflective properties and optionally light transmission properties. This reflectivity is
It also concerns screens made from this composite material.

[Conventional technology and issues to be solved]

Known materials have relatively low reflective properties, and when light is projected onto these materials, it is generally not possible to project light onto them, such as in double-sided or back-projection, where an image projected onto one side of the material is visible from both sides. When light is transmitted through this material, it has a tendency to produce the so-called "hot 5pot" phenomenon, where a very bright localized image of the image of the light source occurs.The present invention aims to solve these drawbacks. With the goal.

[Means to solve the problem]

According to the invention, the composite material comprises at least one base layer and at least one cover layer, particles having reflective properties on at least one side thereof are present in at least one of these layers; The particles are characterized in that they represent at least 3% by weight of the layer in which they are present.

This material may be rigid or highly flexible.

More particularly, this material has at least one base layer made of glass, a rigid synthetic material or a flexible synthetic material, etc., and at least one of its optical surfaces is provided with an external varnish layer.

At least one of these layers is made of at least one layer of homogeneous material (glass, acrylic, etc.).

The material forming the outer layer is, for example, a glycerophthal-based varnish, and the base layer is made of glass.

As another example, the material forming the outer layer is an acrylic or vinyl based varnish, and the base layer is made of a synthetic material such as acrylic or its equivalent.

The base layer made of hard material preferably has a thickness of 1 to 501 m.

The base layer made of flexible material has a thickness of at most 5 days, preferably less than 1 m.

The thickness of the outer layer is 0.05w or less, for example 4μ.
The thickness is preferably about 0,004 m>.

The reflective particles are incorporated into the outer layer.

The particles are preferably made of a suitable metal such as aluminum or an aluminum alloy and have a high diffuse reflectance (AL).
BEDO).

The particles are in the form of substantially parallelepiped platelets with a maximum thickness relative to the thickness of the outer layer.

At least one surface of at least one of the layers is roughened.

The average depth of roughness is DIN (German Industrial Standard N@47
634 and 4764>, from "very fine 3" to "intermediate 1" (0.04 am to 6 μm)
within the range of

In a first embodiment, at least one of the layers of the assembly is at least partially opaque.

In another embodiment, one of the layers of the assembly is partially transparent.

In all embodiments, the base layer is made of a hard or flexible material, while the cover layer is made of a hardened varnish applied in fluid state so as to adhere to the former on at least one side of said base layer. It is being

Preferably, the particles are embedded in at least one of the cover layers.

Although not necessarily essential, it is preferable that the surface of the base layer on which the cover is placed be a rough surface.

At least some of the particles have a size of at least 3 μm and at least some of the particles have a size of at least 20 #
It has a size of m.

The invention also relates to an at least partially opaque screen, said screen comprising at least 15 particles.
%.

In another embodiment of the screen, at least a portion thereof is opaque, at least a portion of said particles have a size of at least 20 μm, and the amount of particles is at least equal to the weight of the layer in which it is embedded. It is equal to 22%.

The invention provides a material according to the invention in which at least some of the particles have a maximum size of 6 μm and the amount of the particles is equal to at least 15% relative to the weight of the layer in which it is embedded. It also relates to screens made that are at least partially translucent or transparent.

In other embodiments of the at least partially opaque screen, at least some of the particles are at least 20μ
m, the amount of particles being equal to at least 22% of the weight of the layer in which they are embedded.

The present invention provides that at least some of the particles have at least 20
μm in size and the amount of said particles is equal to at least 3% with respect to the weight of the layer in which it is embedded, or else at least a portion of said particles are the particles have a size of at least 3 μm and the amount of particles is at least 3% relative to the weight of the layer in which they are embedded;
It also relates to at least partially translucent or transparent screens made of the material of the invention.

However, in all the aforementioned screens, the base layer and the cover layer may be translucent or transparent. In this case, the desired opacity is brought about by the incorporation of appropriate particle amounts and particle sizes in the relevant layers.

It is desirable to roughen at least one surface of the base layer by known means such as sandblasting, hot printing, etc.

For best results in light diffusion (reflection or transmission), it is desirable to have both sides of the base layer roughened, which virtually eliminates the troublesome "hot spot" phenomenon. can.

In general, the materials of the present invention provide improved video quality by using a combination of a roughened base layer surface and a relatively low concentration of reflective particles in at least one layer, such as a cover layer. Not only projection (visible image on the opposite surface onto which the light is projected), but also double-sided imaging (the image can be seen on both sides of the material, although the light is projected onto only one surface). This makes it possible to obtain excellent incident light transmission even for

The average roughness of the surface of the base layer depends on the application and the intensity of the light source.

It is selected appropriately as a function of the distance between the material and the light source, the thickness of the material, etc.

Often 20μm to 30μm with an average size of 25μm
It is desirable to use reflective particles formed at least in part of particles of relatively large size m.

The reflective particles can have any geometric shape.

These particles are located in the embedded layer in a random orientation and in a non-uniform manner. In fact, experience has shown that good light diffusion is obtained with respect to the axis of incidence of the projected light.

〔Example〕

As shown, an assembly E made of composite material 1 is formed from a base layer 11 and a cover layer IO. The base layer 11 is made of acrylic resin, glass, or the like. The cover layer 10 is an acrylic or vinyl glycerophthal based varnish or the like. The thickness e2 of the base layer can reach as much as 5 days depending on the rigidity required for the assembly. The thickness el of the 0 layer 10 is about 4 μm to 30 μm, but in special cases Sometimes it can be reached. Several assemblies E may also overlap each other to form a single multiplex assembly 1. Further, the cover layer covers each surface 111 and 11 of the base layer 11.
2 to form an assembly E or at least a subassembly of a multiple assembly material I.

In the illustrated embodiment, assembly E includes two layers to
, tt, and the reflective particles 3 are embedded in the cover layer 1'0.The degree of inclusion of the reflective particles 3, that is, the number of particles per unit volume and their average size, depends on the application as described below. Varies depending on.

The reflective particles are made of metal, such as aluminum or an aluminum alloy, or are otherwise provided with a reflective material on at least one surface 31 thereof.

This material 1 can be used for screens.

(l) A screen for receiving projections of transparencies, films, images, etc. (on paper). This screen must be opaque. This is obtained by making at least one side 111, 112 of the base layer 11 opaque by using an opaque material for at least one of the layers 10, 11. According to another embodiment:
The surface 111 of layer 10 that contacts surface 102 is made opaque.

It is also possible to obtain at least partial opacity by incorporating the particles 3 at a high mixing degree of 15 to 25% relative to the weight of the layer 10. The average size of the particles for this type of screen should normally not exceed 4 μm.

Such a screen covers a considerable range of angles of incidence α with respect to the surface 101 of the layer 10 (up to about 170°);
Substantially all of the incident light 2 is reflected.

(2) A screen for projecting images received from at least one light source on one and/or the other side of the assembly 101, 112, or only on one of 101 or 112. Screens for projection of transparent films, film, etc., video projection, backside projection, and "double-sided" projection.

This material has a relatively low degree of mixing of translucent or transparent 0 particles 3, about 5%, and the average size of the 0 particles 3 is large, about 25 μm.

According to one embodiment, the composite material 1 shown in FIG. 1 comprises two layers 10.11. This means that layer 11 is a base layer, with a thickness e equal to the sum of the thickness el of layer 10 and the thickness e2 of layer 11. It may be rigid or made of a suitable synthetic material such as glass or acrylic. It can also be made of several different layers of transparent material. Although the thickness of the hard base layer obviously depends on its surface,
In order to obtain the best image on both sides 101 and 112 of
The thickness of this hard base layer 'L1 must be as small as is compatible with the intended application. According to the applicant, excellent results have been obtained using a base layer 11 with a thickness of less than 10n. It turns out that it can be obtained in some cases. A single outer layer 10 is applied to the surface 111 of the base layer 11. In applications where the outer layer is not only on the surface 111 of the layer 11, but also on the surface 111, in order to make it possible to project an image onto either one or the other side of the composite material 1.
2 is also applied. This outer layer lO is 10-15
It is made of a varnish with a specific gravity of g/aJ, in which particles made of reflective material are embedded. The particles are capable of withstanding the chemical components of the varnish and the mechanical stresses during application of the layer IO on layer 11. If the base layer is made of glass or its equivalent, layer 10
The varnish used is a glycerophthal-based varnish. If the base layer is made of synthetic material such as acrylic or its equivalent, the varnish has an acrylic or vinyl base. Experience has shown that the thickness el of this layer 10 is, for example, 4 μm (0,004
m) has a greater thickness. The varnish contains particles made of reflective material. The applicant used aluminum particles 3 which gave good results at relatively low cost. In the illustrated embodiment, these particles 3 have a substantially parallelepiped shape.
It is also irregularly distributed over its width (or length). These particles 3 can assume any orientation within the layer (see the right side of the figure), but in order to understand their effects, it is necessary to place the largest surface of the parallelepiped in layer 1, as shown on the left side of the figure.
It is preferable that it be located parallel to the planes 101 and 102 of 0.

This effect is as follows.

The white or monochromatic light 2 projected onto the surface 101 of the layer 10 is divided into several light rays (21, 22,
23, 24). In order to reduce reflections, it is important that the material forming layer 10.11 is as homogeneous and isotropic as possible. Ray 1. 22. 23. 2
4 (and in the ideal case, the angle of incidence α with respect to the surface 101
The light ray 2) with 2) is reflected by the upper and possibly lower surfaces of the particles 3 or passes through the layers 10, 11 as is.

The light rays reflected by the top surface of the particles 3 produce a good quality image on the surface 101, and the light rays that pass directly through the layer 10.11 or after being reflected from the bottom surface of the particles 3 produce a substantial image on the surface 112. produces the same image.

Layer 11 may be flexible. In this case, the layer is M
It is in the form of a sheet of synthetic material such as YLAR®. It is necessary that this flexible layer 11 has a small thickness, rarely exceeding 1n.

Layer 10 is silk screen printing.

It is applied onto layer 11 by projection without the use of air or oxygen-containing gas, such as rotary roller printing.

To prevent glitter caused by the presence of particles of relatively large size, side 1 of the base layer without a cover layer
It is sufficient to project light (or an image) onto 12. The surfaces are roughened, and the roughness of the surfaces 111, 112 provides the best diffusion of the incident light.

(3) A screen used to extract images obtained by video projection. Material 1 is the above-mentioned item (1)
made opaque in the same way as described in section. The mixing degree is about 25% and the average size of 0 particles 3 is 25μ
It is m.

This large particle size and high degree of mixing can in principle provide the material 1 with sufficient opacity.

The screen thus obtained is very bright and has shown a gain of 10 in tests carried out by the National Film Center Laboratory. The light curve of this screen changes from a substantially overall directional state to a non-directional state, thereby causing the base layer 110 surfaces 112, 11
A screen for the desired purpose can be obtained by selecting a roughness of 200. For example, if the brightness gain is about 4 and the roughness is about 6
A light intensity curve that provides 50% reflected light in the axial direction for an incident angle of 0@ can be selected by selecting the roughness.

Many modifications and improvements can be made to material 1 and the screens made therefrom without departing from the spirit of the invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an embodiment using a translucent or transparent material, and FIG. 2 is a schematic cross-sectional view of an embodiment using an opaque material. 1--Composite material 10--Cover layer 11--Base layer 3--Particles 111, 112... Surface

Claims (1)

Claims: 1. A composite material comprising at least one base layer, at least one cover layer and at least one assembly formed by particles, wherein at least one surface of the particles is reflective. and in at least one of the layers, the amount of particles accounting for at least 3% of the weight of the layer in which they are embedded. 2. The composite material of claim 1, wherein said material is rigid. 3. The composite material of claim 1, wherein the material is flexible. 4. According to any one of claims 1 to 3, comprising at least one base layer made of glass or a hard synthetic material or a flexible material, with an external varnish layer on at least one of its two sides. Composite materials listed. 5. Composite material according to any one of claims 1 to 4, wherein at least one of the layers is formed from at least one layer of homogeneous material (glass, acrylic, etc.). 6. Composite material according to any one of claims 1 to 5, wherein the material forming the outer layer is a varnish based on glycerophthal, and the base layer is made of glass. 7. Any one of claims 1 to 5, wherein the material forming the outer layer is an acrylic or vinyl-based varnish, and the base layer is made of acrylic or an equivalent synthetic material. Composite materials listed in Section. 8. The base layer made of rigid material has a thickness of 1 to 50 mm.
8. A composite material according to any one of claims 1 to 7, having a thickness of . 9. The base layer made of flexible material has a maximum thickness of 5 mm.
Composite material according to any one of claims 1 to 7, having a thickness of , preferably less than or equal to 1 mm. 10. The composite material according to any one of claims 1 to 9, wherein the outer layer has a thickness of 0.05 mm or less. 11. A composite material according to any preceding claim, wherein the reflective particles are incorporated within the outer layer. 12. The particles are made of a suitable metal such as aluminum or its equivalent or an aluminum alloy or its equivalent, and the particles have a high diffuse reflectance (ALBEDO).
The composite material according to any one of the above. 13. The particles have a substantially parallelepiped shape with a maximum thickness relative to the thickness of the outer layer.
2. The composite material according to any one of 2. 14. Composite material according to any one of claims 1 to 13, wherein at least one surface of at least one of said layers is roughened. 15. The average depth of roughness is DIN (German Industrial Standard) N
47634 and 4764, ranging from "very fine" to "medium". Composite material according to item 1. 16. A composite material according to any preceding claim, wherein at least one layer of the assembly is opaque at least in part. 17. Composite material according to any one of claims 1 to 16, wherein all layers are translucent or transparent at least in part. 18. The base layer is made of a hard or flexible material;
Claim 1, wherein the cover layer is made of a hardened varnish or the like, the varnish layer being applied in a fluid state and adhered onto at least one side of the base layer.
18. The composite material according to any one of items 1 to 17. 19. Composite material according to any one of claims 1 to 18, wherein the particles are embedded in at least one of the cover layers. 20. Composite material according to any one of claims 1 to 19, wherein at least one side of the base layer on which the cover layer rests is rough. 21. At least a portion of the particles have a diameter of at least 3 μm.
Composite material according to any one of claims 1 to 20, having a size of . 22. At least some of the particles have a particle size of at least 20μ
Composite material according to any one of claims 1 to 21, having a size of m. 23. At least some of the particles have a size of at most 6 μm, and the amount of particles accounts for at least 15% of the weight of the layer in which they are embedded.
The composite material according to any one of the above. 24. At least a portion of the particles are at least 20 μm
22% of the weight of the layer in which they are embedded.
23. A screen made of a composite material according to any one of Claims 22 to 23. 25. Any one of claims 1 to 22, wherein at least some of the particles have a size of at most 6 μm and the amount of particles accounts for at least 3% relative to the weight of the layer in which they are embedded. A screen made of a composite material according to item 1. 26. At least some of the particles have a size of at least 3 μm, and the amount of particles accounts for at least 3% relative to the weight of the layer in which they are embedded.
A screen made of a composite material according to any one of 2.