JPS58117502A - Light reflecting material - Google Patents

Abstract

PURPOSE:To reflect light convergently within a specific angle range by forming a rugged plastic base surface that angles of inclination to the flat surface are <=10 deg. and peak-to-peak pitch width is 5-1,000mum, and forming a thin metallic film thereupon. CONSTITUTION:On a plastic base 1, a thin metallic film 2 is provided to obtain a light reflecting material. The surface of the base 1 is rugged and the thin metallic film 2 formed on the surface by vapor deposition is also rugged corresponding to said rugged surface. In this case, the rugged surface shape of said base 1 has <=10 deg. angles alpha (alpha1, alpha2-alphan) of inclination to the surface M principally. Then, the pitch width X between peaks 3 is 5-1,000mum and preferably 30- 300mum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to a light reflecting material useful for large screens, and more particularly to a reflective material having a characteristic of reflecting light in a concentrated manner within a range of angles. Regarding.

Aluminum foil has traditionally been used as this type of reflective material. However, the surface of aluminum foil is very easily scratched, and it is also prone to folding and wrinkles, which reduces its function as a reflective material. There was a regret that reflective materials could not be manufactured efficiently.

Furthermore, in the case of aluminum foil, it has been difficult to adjust its surface condition to suitably change its light reflection characteristics.

The present invention aims to solve the above problems and provide a light reflective material with excellent reflective properties that can be used as a reflective material for large screens. is an uneven shape with an inclination angle of 10 degrees or less with respect to the horizontal plane, and a pitch between the crests is in the range of 5 to 1.000 μm, and on top of this is a metal A light reflecting material characterized by forming a thin film.

This invention will be explained below with reference to the drawings.

1 and 2 show an example of the light-reflecting material of the present invention, which is composed of a plastic base 1 and a metal thin film 2 formed thereon, as shown in an enlarged view in FIG. The surface of the base 1 has an uneven shape, and the metal thin film 2 formed on this surface by means such as vacuum deposition also has a surface shape corresponding to the uneven surface.

The uneven shape of the base 1 described in F is as shown in FIG.
゜...αnl+αn) mainly has an inclination of 10 degrees or less. Here, the subject is 1
This means that the inclination angle of 0 degrees or less accounts for 70% or more of the total, particularly preferably 90% or more. In addition, the pitch between each peak 3 in the uneven shape is 11
(xl, X2,...xn) are all 5~
It is set in the range of 1.000 μm, preferably in the range of 30 to 300 μm.

By the way, there is an optimum viewing angle for screens, etc., and it is known that if the viewing angle is deviated from this angle, the picture becomes dark or difficult to view. That is, generally, as shown in FIG. 4, the maximum angle θ at which the light from the light source hits the screen 4 and is reflected is 10 to
It is said that the optimum angle is when the angle is 20 degrees.If the angle is smaller than the above, the visible range of the screen is too narrow, and if the angle is larger than the above, the entire screen becomes dark.

As a result of repeated experiments and studies on the relationship between the surface condition and the optimum viewing angle by changing the surface condition of the base 1 using light-reflecting material, we found that it is easier to see if the surface condition is set as explained in Fig. 3 above. It has been discovered that a bright reflective material for screens can also be obtained.

In other words, if the inclination angle α with respect to the horizontal plane M is not mainly 10 degrees or less, the reflected light will be scattered over a wide range, making it impossible to obtain a bright screen. When X is smaller than 5 centimeters, it approaches the order of the wavelength of visible light, so the screen becomes darker due to its interference, and an additional 1,000 μ? If it is larger than n, the unevenness of the reflective material itself will be observed, and the precision of the screen will be lost. On the other hand, if the setting is within the above range, the above problems will not occur at all, and
The screen becomes bright and easy to see.

Further, according to the above structure of the present invention, since the plastic base is used as the support instead of using only the metal thin film as the reflective material, there is no fear of scratches, wrinkles, or folds during manufacturing or handling, and it is suitable for large screens. Not only can it be manufactured efficiently, but it can also be easily incorporated into a screen.

Moreover, as mentioned above, excellent light reflection properties can be obtained by setting the plastic-based surface condition, and setting the above surface condition does not change the surface shape of the metal thin film itself such as aluminum foil. Unlike, it can be easily done by chemical treatment and various surface treatment steps.
Preparation I--Can be carried out very advantageously. Moreover, ``)1
It is possible to set various surface conditions within the range described in 1.
This allows the light reflection characteristics to be changed freely.

Now, we will explain the manufacturing method of the light-reflecting material of the present invention having the above structure. First, the plastic base is surface-treated to form the uneven shape as described above, or the plastic base used here is In general, materials are selected that have environmental resistance such as heat resistance and moisture resistance that can be used indoors, and do not interfere with metal thin film formation operations (evaporation, bonding, etc.).Specifically, polyethylene terephthalate film, polyvinyl chloride film,
Examples include polyacrylic film, polycarbonate film, and polypropylene film. The thickness of this base is not particularly limited, but is generally about 0.02 to 1 mm thick.

Examples of surface treatment methods include embossing, sand matting, and chemical treatment. By appropriately determining the conditions for each treatment method, it is possible to produce products that have an inclination angle of 10 degrees or less with respect to the horizontal plane, or have a main inclination and a pitch between the ridges of 5 to 1,000 μm. Forms an uneven shape within a range.

By providing a metal thin film on this surface-treated base, the light-reflecting material of the present invention can be obtained.

Examples of methods for forming the metal thin film include vacuum evaporation, sputtering, and ion blating, and in some cases, a method of bonding metal foils together using an appropriate adhesive may also be adopted. As for the type of metal, aluminum is preferred because of its excellent light reflection properties, but other metals may also be used. The thickness of the metal thin film is generally 0.02
It is about 0.2 μm.

As described in detail below, according to the present invention, it is possible to provide an industrially useful light-reflecting material that has excellent reflective properties that can be applied to large screens, and that can freely change the reflective properties. The manufacturing efficiency can be improved.

Examples of the present invention will be described below.

Example 2 A polyvinyl chloride film with a thickness of 00 μm was surface-treated by the embossing method, and the inclination angle with respect to the horizontal plane was 1.
f4 is the slope where the angle below 0 degrees is 80% or more.
An uneven shape having L length and a pitch between ridges in the range of 30 to 50 μm was provided.

At the same time, the surface-treated plastic base described above was set in an empty evaporator 4 with the surface-treated side facing the evaporation surface, aluminum was used as the evaporation metal, and the evaporation rate was 0.
．． Heat vapor deposition was performed at 1 μm/min.

As a result, an aluminum thin film having a thickness of 0.06 μm was formed on the base.

When we constructed a screen by incorporating the light-reflecting material obtained in this way into a large screen substrate (720 mm long and 950 mm wide), no scratches, folds, or wrinkles occurred during the assembling process. Ta. Furthermore, when we used this screen to display images, we found that a very bright and easy-to-see screen was obtained.

In order to numerically determine the optimal viewing angle range and brightness of the screen, the following tests were conducted and the results are shown in the table below.

Comparative Examples 1 to 3 in the table are test results for light-reflecting materials manufactured in the same manner as in the above examples except that the uneven shape of the base surface was outside the setting range of the present invention.

(Optimal Viewing Angle Range) Reflection characteristics were observed using a new Goniophotometer CP-1k manufactured by Mura and L Color Technology Research. In FIG. 4, the light reflection intensity was measured while changing the angle θ, and the angle at which the intensity was 1/2 of that at 0 degrees was determined.

(Brightness) The light reflection intensity at an angle of 0 degrees was measured using the same measuring device as in Section L, and the light reflection intensity in the case of Kent paper was taken as 1, and the ratio was expressed.

(Notes) 1) Items with an inclination angle of 10 degrees or less relative to the horizontal plane, with a slope as low as approximately 40%.

2) The pitch between the peaks is 2 μm.

3) The pitch between the peaks is 1,500 μm.

4) The image quality seemed grainy because the unevenness was visible to the naked eye.

It can be seen from the results listed below that the light-reflecting material of the present invention has extremely excellent light-reflecting properties.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example of the light-reflecting material of the present invention, Fig. 2 is an enlarged cross-sectional view of the part ■ in Fig. 1, and Fig. 3 is an enlarged view for explaining the surface shape of the plastic base of the present invention. The cross-sectional view, FIG. 4, is a schematic diagram for explaining the optimum viewing angle on the screen. 1...Plastic base, 2...Metal thin film, 3.
...Mountain, M...Horizontal plane, α...Inclination angle, X...Middle pitch. Patent applicant Nitto Electric Industry Co., Ltd.

Claims (1)

[Claims] (11) The surface of the plastic base has an inclination that is mainly 10 degrees or less with respect to the horizontal plane, and the pitch between the ridges is 5 to 1.000I14n.
1. A light-reflecting material characterized by having an uneven shape within the range of 1 to 3, and having a thin metal film formed thereon.