JPS6128903A - Reflector - Google Patents

Abstract

PURPOSE:To increase the surface reflectivity of an aluminum substrate and to decrease the scattering property of the aluminum substrate surface by providing alternately a soln. of an org. metallic compd. or a soln. of metallic hydroxide on the aluminum substrate then calcining the same. CONSTITUTION:The reflector consists of the aluminum substrate 11 having about 80% surface reflectivity and relatively low purity, the layer 12 consisting of SiO2 having 50-80nm geometrical film thickness and the layer 13 consisting of TiO2 having 50-80nm geometrical film thickness. The optical thickness of the layers 12, 13 is approximately lambda/4 thickness or the thickness of 2n-1 times lambda/4 if the design wavelength is designated as lambda, where n is a natural number. The reflection increasing films 12, 13 provided on the reflector are formed by a soln. coating method. Said films are formed by coating first the soln. of the org. compd. of Si on the substrate 11 and coating further the soln. of the org. compd. of Ti thereon then heating the coating for about 30min at about 150-380 deg.C, more preferably about 250 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reflector suitable as a member of a reflective shade of a lighting device in, for example, a copying machine, a facsimile machine, etc.

Conventionally, the materials for reflective shades used in lighting devices for various office machines have been (a) aluminum electrolytically polished and anodized, and (b) low-purity aluminum Ml as shown in Figure 3. A member on which a high-purity aluminum layer 2 is laminated, (c) As shown in FIG. 4, on the member shown in (b) above,
(d) A member in which a protective layer 3 of SiO2 or the like is provided, and (d) a member in which a multilayer film is provided on an aluminum substrate by vacuum evaporation.

However, the member shown in (a) has a problem in that the absolute reflectance on its surface (hereinafter simply referred to as surface reflectance) is extremely low. In addition, the member shown in (b) uses aluminum layer 2 of high purity, so that the aluminum layer 2
Although the surface reflectance of the aluminum layer 2 can reach 85% to 87%, the luminous flux reflected on the surface of the aluminum layer 2 has a much larger scattered luminous flux component than the specularly reflected luminous flux.

Like this.

The large number of scattered components makes it difficult to accurately illuminate a desired illumination area when used in a reflective shade of a lighting device. In other words, the efficiency of concentrating the luminous flux on a desired illumination area decreases, making it impossible to provide highly efficient illumination. Furthermore, the member shown in (b) also has poor weather resistance. or,(
The member shown in c) has a lower S i than the member shown in (b).
Since the layer 3 of 02 is provided on the high-purity aluminum layer 2 with a thickness that is an integral multiple of λ/2 (where λ is the design wavelength), the weather resistance problem is improved, but the scattering problem mentioned above is improved. is not sufficiently improved, and furthermore, the surface reflectance is 85% to 87%.
In the case of the member shown in (d), the surface reflectance of the aluminum substrate is increased by providing multiple layers of very thin films by vapor deposition. However, it is not possible to reduce the scattered components on the surface of the aluminum substrate.Furthermore, the biggest difficulty in (d) is that the film is provided on the aluminum substrate by vapor deposition, which increases the cost and makes mass production difficult. It is difficult to coat a member with a large surface due to the wrong orientation and the size of the vapor deposition tank.

An object of the present invention is to provide a reflector using aluminum as a substrate, which can increase the reflectance of the aluminum surface by means for easy mass production.

A further object of the present invention is that, compared to a conventional reflector having an aluminum substrate, upon reflection on the surface of an aluminum substrate, the proportion of the scattered light flux component is smaller than the specularly reflected light flux component. It's about offering your body.

A further object of the present invention is to provide a reflector with excellent weather resistance on the surface of an aluminum substrate.

In the reflector according to the present invention, T i , Z r
.

A solution of an organic compound of a metal such as Ta or In or a solution of a metal hydroxide, and a solution of an organic compound of a metal such as Si,
Alternately applied on an aluminum substrate using a solution coating method such as dipping or spinner.

The above object is achieved by subsequently heating and firing to form alternating layers of high refractive index dielectric layers and low refractive index dielectric layers on the aluminum substrate.

Therefore, in the reflector according to the present invention, TiO2 and ZrO2 are finally formed on the aluminum substrate.

Although alternating layers of high refractive index dielectric layers such as Ta2OS and In7O3 and low refractive index dielectric layers such as SiO2 are formed, since they are formed by a solution coating method,
The surface reflectance can be increased by about 5% to 10% compared to the reflectance of the aluminum surface of the substrate itself, and the scattering of reflected light beams can be significantly reduced. As the organometallic compound used in the present invention, (a) a metal halide and a carboxylic acid are reacted, the halogen is removed by a reduced pressure method if necessary, and the reaction product is further reacted with an alcohol. (b) A solution obtained by reacting a metal alcoholade and a lower fatty acid in an organic solvent in the presence of a catalyst and diluting the solution with an appropriate organic solvent.

etc. can be used. The present invention will be explained in detail below.

FIG. 1 is a sectional view showing an embodiment of a reflector according to the present invention. In Figure 1, 11 has a surface reflectance of 80%.
Aluminum substrate with relatively low purity, 12 is 50
3i02 (7) with geometric thickness from nm to 80 nm
Layer 13 is a layer of TiO2 with a geometric thickness of 50 nm to 80 r+mc7). The optical thickness of each layer (12, 13) is approximately λ/4 or approximately (2n −1) times λ/4 when the design wavelength is included. However, n is a natural number. The reflection increasing films (12, 13) provided on the reflector shown in FIG. 1 were formed by a solution coating method.
It is formed by applying a solution of an organic compound of , further applying a solution of an organic compound of Ti on top of that, and then heating at a temperature of 150°C to 380°C, preferably about 250°C for about 30 minutes. It is. When this reflection increasing film is provided, the reflectance of the aluminum substrate 11 is increased by about 5% to 10%, and therefore the reflectance of the aluminum substrate 11 is about 85% to 87%.

FIG. 2 is a sectional view showing another embodiment of the reflector according to the present invention. In Figure 2, 21 is an aluminum substrate of relatively low purity, and 22 is a high purity one with a surface reflectance of 85.
% to about 87%, and a high purity aluminum layer 22 is provided on the aluminum substrate 21 by lamination processing. 23 and 25 are 30 nm
A layer of TiO2 with a geometric thickness of ~70 nm, 24
is SiO2 with a geometric thickness of 30 nm to 70 nm.
This is the layer of In order to increase reflection, it is desirable that the optical thickness of these layers (23, 24, 25) be approximately (2n-1)·λ/4, which is the wavelength of the design wavelength. Further, these reflection increasing films (23, 24, 25) are formed through the same process as the reflection increasing film shown in FIG. 1, and will not be described here. By providing the reflection increasing film shown in FIG. 2, the surface reflectance of the aluminum layer 22 can be increased by 5.
It is possible to increase by about 10%, therefore 85% to
The reflectance of the aluminum layer 22, which is about 87%, is reduced to 93% to 9.
The reflectance can be increased to about 5%, and a reflectance almost equivalent to that achieved by vacuum deposition can be obtained.

In addition, the reflectors shown in FIGS. 1 and 2 increase the proportion of specularly reflected luminous flux in all the reflected luminous flux reflected from the surface compared to the proportion of specularly reflected luminous flux in conventional reflectors. I was able to do it. In other words, it is possible to reduce the proportion of scattered reflected light flux in all reflected light flux, for example,
In the reflector shown in Figure 4, the ratio of scattered reflected light flux is approximately 8.
%, but in the reflectors shown in FIGS. 1 and 2, the ratio of scattered reflected light flux could be reduced to approximately 3%.

In addition to the above-mentioned effects, the reflector shown in this application has excellent weather resistance against high temperatures, high temperatures, and external environments such as ozone, and can be easily reflected by adjusting the coating amount during dipping. The thickness of the dielectric layer forming the increase film can be adjusted, and the wavelength range in which one reflection is to be increased can be freely selected. Needless to say, it is low cost and suitable for mass production.

[Brief explanation of the drawing]

1 and 2 are diagrams showing the structure of a reflector according to the present invention, and FIGS. 3 and 4 are diagrams showing the structure of a conventional reflector. [1, 21... Lu aluminum substrate. 12.2411...SiO2 layer, 13.23.25@...TiO2 layer, 22...High purity aluminum layer.

Claims (5)

[Claims] (1) A dielectric layer with a high refractive index and a dielectric layer with a low refractive index formed by applying a solution of an organometallic compound or a solution of a metal hydroxide on an aluminum substrate and then firing it. By providing a thin film consisting of alternating layers,
A reflector characterized by increasing the surface reflectance of an aluminum substrate and reducing the scattering property of the surface of the aluminum substrate. (2) The thin film consisting of the alternating layers has a low refractive index dielectric layer with an optical thickness of approximately (2n-1)λ/4 from the aluminum substrate side, where λ is the design wavelength and n is a natural number. 2. The reflector according to claim 1, wherein high refractive index dielectric layers having a target thickness of approximately (2n-1)λ/4 are sequentially laminated. (3) The thin film consisting of the alternating layers has a high refractive index dielectric layer with an optical thickness of approximately (2n-1)λ/4 from the aluminum substrate side, where λ is the design wavelength and n is a natural number. A patent claim in which a low refractive index dielectric layer with an optical thickness of approximately (2n-1)λ/4 and a high refractive index dielectric layer with an optical thickness of approximately (2n-1)λ/4 are sequentially laminated. The reflector according to item 1. (4) The high refractive index dielectric layer is made of TiO_2, ZrO_
2. The reflector according to claim 2 or 3, which is made of any one of the following substances: Ta_2O_5 and In_2O_3. (5) The reflector according to claim 2 or 3, wherein the low refractive index dielectric layer is made of SiO_2.