JPH06130210A - Surface reflection mirror - Google Patents

Abstract

PURPOSE:To provide the surface reflection mirror having excellent practicable durability, such as moisture resistance and weatherability by laminating a dielectric film, two layers of metallic films and a dielectric film in this order on the surface of a substrate and determining the materials and the thickness of the respective film to obtain the desired spectral reflectance. CONSTITUTION:A thin film consisting of SiO is formed by vacuum vapor deposition at a prescribed thickness on the surface of the glass substrate 10 to form the dielectric film 12. Al is deposited by evaporation at a prescribed thickness on the thin film consisting of the SiO to form the metallic film 14. The metallic film 14 does not allow the transmission of light of a visible region. Further, Cr is deposited by evaporation at a prescribed thickness to form the metallic film 16. Al3O3 is deposited by evaporation at a prescribed thickness on the thin film consisting of the Cr to form the metallic film 18. Namely, the dielectric film 12 is formed on the surface of the substrate 10 and two layers of the metallic films 14, 16 are held by the dielectric film 12 and the other dielectric film 18 formed in the uppermost part. Two layers of the metallic films 14, 16 are, therefore, protected from the outside by the dielectric film 18 of the uppermost part and are securely integrated to the substrate 10 by the dielectric film 12 on the surface of the substrate 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface reflecting mirror.
The surface reflecting mirror of the present invention can be used for automobile mirrors and the like.

[0002]

2. Description of the Related Art A reflecting mirror as an optical element is often required to have a specific spectral reflectance depending on the purpose of use. In addition, although the reflecting mirror is often used in a natural environment, in the case of a front surface mirror, the mirror surface component is exposed, so
It is desirable that the mirror-finished component has excellent moisture resistance and weather resistance.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a surface reflecting mirror excellent in practical durability such as moisture resistance and weather resistance.

[0004]

As shown in FIG. 1, a surface reflecting mirror of the present invention has a structure in which "a dielectric film 12, two metal films 14 and 16 and a dielectric film 18 are formed on a surface of a substrate 10. , Laminated in the above order to obtain the desired spectral reflectance,
The material and thickness of each of the films 12, 14, 16 and 18 have been determined ”.

The four layers of thin films formed on the surface of the substrate can be thin films made of SiO, Al, Cr, and Al ₂ O ₃ in order from the substrate side (claim 2). In this case, the geometric thicknesses of the thin films made of SiO, Cr, and Al ₂ O ₃ can be set to 483Å, 120Å, and 655Å, respectively, and the thickness of the thin film made of Al can be set to 841Å or more. (Claim 3), or SiO, Al, C
The geometrical thicknesses of the thin films made of r and Al ₂ O ₃ can be 483Å, 483Å, 120Å, and 655Å, respectively (claim 4).

[0006]

As described above, in the surface reflecting mirror of the present invention, the dielectric film is formed on the surface of the substrate, and this dielectric film and the other dielectric film formed on the uppermost layer form a two-layer metal. The structure is such that the membrane is sandwiched. Therefore, the two-layer metal film is protected from the outside by the uppermost dielectric film, and
The dielectric film on the surface of the substrate firmly integrates with the substrate.

A desired spectral reflectance can be obtained by adjusting the material / thickness of each film. However, by adjusting the film thickness of the dielectric film, the P-polarized component and the S-polarized component of the reflected light can be obtained. It is also possible to give a desired phase difference between the two.

[0008]

【Example】

Example 1 A glass substrate was used as the substrate 10 in FIG. The inside of the vacuum chamber is evacuated to 5 × 10 to ⁵ mmHg or less, and a glass substrate having a sufficiently clean and smooth surface is provided, and a thin film of dielectric: SiO is formed on the surface by vacuum vapor deposition to a thickness of 483Å. To form the dielectric film 12.

On the above-mentioned SiO thin film, further, metal: Al
Was evaporated to a thickness of 841Å or more to form a metal film 14. This metal film does not transmit light in the visible region. More metal:
Cr was vapor-deposited on 120Å to form a metal film 16.

On this Cr thin film, a dielectric material: Al ₂ O ₃
Was deposited to a thickness of 655 Å to form a dielectric layer 18.

FIG. 2 shows the spectral reflectance in the visible region when light is incident on the surface reflecting mirror of Example 1 at an incident angle θ (see FIG. 1) of 45 degrees. In the figure, Rp, Rs
Are the reflectances of the P-polarized component and the S-polarized component, respectively,
RH represents the average of these. The transmittance is almost 0 in the entire visible region. The spectral reflectance characteristic of FIG. 2 is suitable for an anti-glare mirror such as an automobile.

As a result of the environmental resistance test, it was found that the surface reflecting mirror of Example 1 had extremely excellent practical durability. Since the incident angle giving the above-mentioned spectral reflectance characteristic is 45 degrees, the surface reflecting mirror of Example 1 can be suitably used as a door mirror of an automobile.

Comparative Example 1 The inside of a vacuum chamber was evacuated to 5 × 10 to ⁵ mmHg or less, and a glass substrate having a sufficiently clean and smooth surface was provided, and the surface of the metal: Al was 841 Å or more directly. Then, metal: Cr was vapor-deposited on it to a thickness of 120Å, and a dielectric: Al ₂ O ₃ was vapor-deposited thereon to a thickness of 655Å.

The surface reflecting mirror thus formed has a structure in which the dielectric film made of SiO is removed from the structure of the first embodiment, and its spectral reflectance is the spectral reflection of the first embodiment as shown in FIG. It is almost the same as the rate. Therefore, the surface reflecting mirror of Comparative Example 1 is also suitable as an anti-glare mirror in terms of only the spectral reflectance characteristic. However, the surface reflecting mirror of Comparative Example 1 was formed directly on the substrate when placed in a high humidity condition.
The thin film of 1 is easily peeled off from the substrate and lacks practical durability.

Example 2 A glass substrate was used as the substrate 10 in FIG. The inside of the vacuum chamber is evacuated to 5 × 10 to ⁵ mmHg or less, and a glass substrate having a sufficiently clean and smooth surface is provided, and a thin film of dielectric: SiO is formed on the surface by vacuum vapor deposition to a thickness of 483Å. To form the dielectric film 12.

On the above-mentioned SiO thin film, a metal: Al
Was deposited to a thickness of 483Å to form a metal film 14. Further, metal: Cr was vapor-deposited on 120 Å to form a metal film 16.

On this Cr thin film, a dielectric material: Al ₂ O ₃
Was deposited to a thickness of 655 Å to form a dielectric layer 18.

The incident angle: θ was set to 3 on the surface reflecting mirror of Example 2.
FIG. 3 shows the spectral reflectance in the visible region when light is incident at 0 degree. The transmittance is almost 0 in the entire visible region. The spectral reflectance characteristic of FIG. 3 is also suitable for an anti-glare mirror such as an automobile.

As a result of the environment resistance test, the surface reflecting mirror of Example 2 was also found to have extremely excellent practical durability. Since the incident angle giving the spectral reflectance characteristic is 30 degrees, the surface reflecting mirror of Example 2 can be suitably used as an inner mirror of an automobile.

Comparative Example 2 The inside of the vacuum chamber was evacuated to 5 × 10 to ⁵ mmHg or less, a glass substrate having a sufficiently clean and smooth surface was placed, and metal: Al was directly applied to the surface to a thickness of 483Å. After vapor deposition, metal: Cr was vapor-deposited on it to a thickness of 120Å, and a dielectric: Al ₂ O ₃ was vapor-deposited thereon to a thickness of 655Å.

The surface reflecting mirror thus formed has the same structure as that of the second embodiment except that the dielectric film made of SiO is removed, and its spectral reflectance is as shown in FIG. It is almost the same as the rate. Therefore, the surface reflecting mirror of Comparative Example 2 is also suitable as an anti-glare mirror in terms of only the spectral reflectance characteristic. However, the surface reflecting mirror of Comparative Example 2 was also formed directly on the substrate when placed in a high humidity condition.
The thin film of 1 is easily peeled off from the substrate and lacks practical durability.

[0022]

As described above, according to the present invention, a novel surface reflecting mirror can be provided. Since the surface reflecting mirror of the present invention has the above-described structure, it is possible to easily realize a surface reflecting mirror having a desired spectral reflectance and also have extremely good practical durability.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a configuration of a surface reflecting mirror of the present invention.

FIG. 2 is a diagram showing a spectral reflectance of a surface reflecting mirror of Example 1.

FIG. 3 is a diagram showing a spectral reflectance of a surface reflecting mirror of Example 2.

FIG. 4 is a diagram showing a spectral reflectance of a surface reflecting mirror of Comparative Example 1 with respect to Example 1.

FIG. 5 is a diagram showing a spectral reflectance of a surface reflecting mirror of Comparative Example 2 with respect to Example 2.

[Explanation of symbols]

 10 substrate 12 dielectric film 14 metal film 16 metal film 18 dielectric film

Claims (4)

[Claims] 1. A dielectric film, a two-layer metal film, and
A surface reflecting mirror, characterized in that dielectric films are laminated in the above-mentioned order, and the materials and thicknesses of the respective films are determined so as to obtain a desired spectral reflectance. 2. The surface reflecting mirror according to claim 1, wherein the four layers of thin film formed on the surface of the substrate are sequentially arranged from the substrate side.
A surface reflecting mirror characterized by being a thin film made of SiO, Al, Cr, Al ₂ O ₃ . 3. The surface reflecting mirror according to claim 2, wherein the thin films made of SiO, Cr and Al ₂ O ₃ have geometrical thicknesses of 483Å, 120Å and 655Å, respectively.
A surface reflecting mirror characterized in that the thickness of the thin film made of Al is 841 Å or more. 4. The surface reflecting mirror according to claim 2, wherein the thin films made of SiO, Al, Cr and Al ₂ O ₃ have geometrical thicknesses of 483Å, 483Å and 120Å, respectively.
A surface reflecting mirror characterized by being 655 Å.