JPH02148003A - Surface reflecting mirror made of multilayered film - Google Patents

Abstract

PURPOSE:To obtain the reflecting mirror which is excellent in an antidazzle property and visibility and is excellent in productivity by providing dielectric films of >=1 layers of refractive index material layers having 3lambda0/4 optical film thickness on a metal or semiconductor film provided on a base material. CONSTITUTION:A Cr film 2 is formed as the metal or semiconductor film on the base material 1 consisting of glass, plastic, etc. The refractive index film layer (3M layer) 3 consisting of SiO2 having 3lambda0/4 optical film thickness (where lambda0 is a design wavelength and the film thickness is 405nm if this wavelength is assumed to be 540nm) and 1.46 refractive index is formed on this film. Oxides, such as TiO2, fluorides, such as MgF2, and sulfides, such as ZnS, are used in addition to the above-mentioned material as the refractive index film layer. As a result, the reflectivity is low at 480 to 600nm and the excellent antidazzle property is obtd.; in addition, the reflectivity of the other wavelengths is high and the visibility is assured. Since the number of the layers of the dielectric films is small, the reflecting mirror having the excellent productivity and cost characteristic is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a reflecting mirror, and particularly to a multilayer film surface reflecting mirror that is excellent in anti-glare properties, high visibility, decorative properties, productivity, cost efficiency, etc. The multilayer film surface reflecting mirror of the present invention is mainly used for automobile rearview mirrors, convex mirrors (curved mirrors) for road hazard prevention, decorative mirrors, etc., but is also widely used for other uses.

"Prior art" As an example of a multilayer film surface reflecting mirror, Japanese Patent Application Laid-Open No. 63-1658
No. 05 discloses that a dielectric multilayer film is provided on one side of a glass substrate, and a light absorption film is further provided on the back side of the same substrate, and the dielectric multilayer film has three dielectric films having different refractive indices alternately. It is constructed by sequentially laminating ~6 layers, and at least one layer of the 3 to 6 dielectric films constituting the dielectric multilayer film has λ
A multilayer surface reflector having an optical thickness of /2 is disclosed.

The scotopic specific luminous efficiency V′(λ)(
(see curve (1) in the figure), spectral energy characteristics P(λ) of automobile headlights (halogen lamps) (see line (2) in the figure), and their product P(λ)xv'(λ)
(See curve (3) in the same figure) As is clear from the figure, the wavelength of light that is perceived by the headlights of the following vehicle at night is mainly 48
0 nm to 550 nm, and a low reflectance in this wavelength range is an important factor for obtaining an anti-glare effect. As shown in FIG. 3, its spectral reflectance characteristics show that the reflectance is low in the wavelength range of 480 nm to 550 nm, and the anti-glare effect is excellent. Further, this reflecting mirror has a low reflectance in the wavelength range necessary for anti-glare, and a high reflectance in other wavelength ranges, so it has excellent visibility.

[Problems with the Prior Art] However, the multilayer film surface reflecting mirror described in JP-A No. 63-165805 has a large number of dielectric multilayer films, 3 to 6 layers, provided on one side of the glass substrate. Not only is the vacuum deposition process for forming multilayer films complicated;
Painting on the back side of the same substrate in a separate process from the vacuum deposition process,
Since it is necessary to form a light absorber film by baking, there is a drawback that productivity is poor and costs increase.

1 [Problems to be Solved by the Invention] The purpose of the present invention is to solve the above-mentioned problems of conventional surface reflecting mirrors, and to provide not only excellent anti-glare properties and visibility, but also productivity and cost efficiency. It is an object of the present invention to provide an excellent surface reflecting mirror for various purposes such as the above.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and the multilayer film surface reflecting mirror of the present invention includes a metal or semiconductor film provided on one side of a base material, Furthermore, a dielectric film having an optical thickness of 3λ0/4 (λ0 is the wavelength of light that is the center of the design) consisting of one or more refractive index material layers is provided thereon.

The present invention will be explained in detail below.

The base material used in the multilayer film surface reflecting mirror of the present invention is preferably a transparent base material, but the base material does not have to be transparent. This base material is preferably a substrate having flat surfaces on both sides, or a substrate having at least one convex or concave surface (for example, a plano-concave plate, a plano-convex plate, a concave-convex plate, a biconcave plate, a biconvex plate, etc.). Preferred materials for the base material include glass and plastic, but other materials can also be used.

In the multilayer film surface reflecting mirror of the present invention, a metal or semiconductor film is provided on one side of the base material, and a dielectric film is further provided on the metal or semiconductor film.

First, a description will be given of the metal or semiconductor film provided on one side of the base material in the multilayer film surface reflecting mirror of the present invention.

This metal or semiconductor film functions as a reflective film, and it is preferable to use one having a reflectance of 30% or more, particularly 50 to 80%. Such metal or semiconductor films include C1-5Ni, Rh, AI, Ag, Co
, simple metals or semiconductors such as Fe, Si, Ge,
An alloy containing at least one of these metals or semiconductors is used. An example of an alloy is Inconel (N
Mainly composed of 80% by weight of Ni, 14% by weight of Cr, and 6% by weight of Fe, including a small amount of impurities) and chromel (mainly composed of 80% by weight of Ni, 14% by weight of Cr2O, and containing a small amount of other impurities). . The metal or semiconductor film may be formed of a single metal or semiconductor layer, but in order to increase the reflectance of the mirror in the visible range, a different type of material with higher reflectivity may be added on top of the single metal or semiconductor layer. A metal or semiconductor film can also be formed.

Furthermore, three or more types of metal or semiconductor layers may be formed.

The method for forming this metal or semiconductor film is the same coating method as for the dielectric film described later (evaporation method, sputtering method, ion blating method, CVD method, etc.).
will be adopted.

Next, to explain the dielectric film provided on the metal or semiconductor layer, this dielectric film consists of one or more refractive index material layers and has an optical thickness of 3^0/4 (λO is the center of the design). It is a dielectric film with a wavelength of light that is Here, the refractive index material layer is preferably formed of a refractive index material having a refractive index of 1.3 to 2.4, and examples of such refractive index materials include Sin, TiO2, Ta205, and Zr.
Oxides such as O2,5i02, HfO2, and AI203, fluorides such as MgF2 and CeF3, sulfides such as ZnS, and mixtures thereof are used as appropriate.

As mentioned above, the optical thickness of the dielectric film is limited to 3λ0/4. The reason why this film thickness is limited to the above range is that only by this limitation can a reflective property with excellent anti-glare properties and visibility be obtained.

The dielectric film having an optical thickness of 3λO/4 may be formed by a single refractive index material layer;
A dielectric film having an optical thickness of 3λo/4 is formed by one type of refractive index material layer and an adjacent refractive index material layer of another type having an optical thickness of 2^o/4. Also good.

Further, a refractive index material layer having an optical thickness of λo/4 and λ
A dielectric film having an optical thickness of 3λO/4 may be formed by a layer of another type of refractive index material of 0/4 and a layer of another type of refractive index material of λO/4. Further, the dielectric film having an optical thickness of 3λo/4 includes one type of refractive index material having an optical thickness of λo/4, and another type of refractive index material having an optical thickness of λo/4 provided on both sides of the dielectric substance and film. The refractive index material layers formed by the refractive index material layers and provided on both sides may be of the same type.

Examples of methods for forming this dielectric film include physical coating methods such as vapor deposition, sputtering, and ion-blating, and coating methods such as CVD and thin film formation from an organic solution.

[Examples] Preferred specific examples of the present invention will be described below with reference to Examples, but the present invention is not limited to these Examples.

Embodiment 1 FIG. 1(A) is an enlarged cross-sectional view of the main parts of a preferred embodiment of the multilayer film surface reflecting mirror of the present invention, in which 1 is a glass substrate;
2 is a Cr film, 3 is an SiO2 film with a refractive index of 1.46, and has an optical film thickness of 3λo/4 (in this example, the wavelength λ0 of light, which is the center of the design, is 540 nm, so the optical film thickness is 3λo/4).
4 is a refractive index film layer (3M layer) with a thickness of 405 nm. That is, in the multilayer film surface reflecting mirror of this embodiment, a multilayer film is formed on one side of a glass substrate in the order of C1-film-3M layer from the substrate side. The spectral reflection characteristics of this multilayer surface reflecting mirror are shown in FIG. As is clear from FIG. 4, the multilayer film surface reflector of this example is used in a region where the product of the scotopic specific luminous efficiency and the spectral energy of heradrite is higher than that of the multilayer film surface reflector of the comparative example described later. Approximately equivalent to 480nm-58
400nI11 to 480nIl+ (blue) and 58 which are blue and red wavelengths with low brightness sensitivity for the human eye and have excellent anti-glare properties because the reflectance at 0 nm is reduced.
Since the reflectance from 011111 to 700t1m (red) is increased, visibility is excellent.

Embodiment 2 FIG. 1(B) is an enlarged sectional view of main parts of another embodiment of the multilayer film surface reflecting mirror of the present invention, in which 1-1- is a glass substrate, 12 is a Cr film, and 13 is a Rh film, 14 has a refractive index of 1446
A refractive index film layer (3M layer) consisting of S i 02 and having an optical thickness of 3λO/4 (in this example, the wavelength of light that is the center of the design is 540 nm, so 3λo/4 is 405 nm). It is.

That is, in the multilayer film surface reflecting mirror of this embodiment, a multilayer film is formed on one side of a glass substrate with 3M layers between the C1 film and the RhRh film from the substrate side.

As is clear from FIG. 5, this multilayer film surface reflector exhibits substantially the same spectral reflection characteristics as the multilayer film surface reflector of Example 1, and has excellent anti-glare properties and visibility. In addition, the overall reflectance was improved compared to the multilayer film surface reflector of Example 1.
It has high reflectivity.

Embodiment 3 FIG. 1(C) is an enlarged sectional view of main parts of another embodiment of the multilayer film surface reflecting mirror of the present invention. In FIG. 18, 21 is a glass substrate;
2 is a Ge film, 23 is an 8102 film with a refractive index of 1.46, and has an optical film thickness of 3^O/4 (in this example, the wavelength λ0 of light, which is the center of the design, is 540 nm, and therefore 3λo/4).
4 is a refractive index film layer (3M layer) with a thickness of 405 nm. That is, in the multilayer film surface reflecting mirror of this embodiment, a multilayer film is formed on one side of a glass substrate in the order of Ge film and 3M layer from the substrate side.

As shown in FIG. 6, this multilayer film surface reflector exhibits substantially the same spectral reflection characteristics as the multilayer film surface reflector of Example 1, and has excellent anti-glare properties and visibility.

Example 4 Figure 1 (D> is an enlarged sectional view of the main part of another example of the multilayer film surface reflecting mirror of the present invention, in which figure r4=1, 31 is a glass substrate, 32 is a Cr film, and 33 is a S with a refractive index of 12.46],
02, the refractive index film layer (M1 layer) with an optical film thickness λo/4 (in this example, the wavelength λ0 of the light that is the center of the design is 540 nm, and therefore λo/4 is 1350 m), 34 is A refractive index film layer (2M2 layer) with an optical thickness of 2λo/4 (270 nm) made of Al2O3 with a refractive index of 1.63.
It is. That is, in the multilayer film surface reflecting mirror of this embodiment, a multilayer film is formed on one side of a glass substrate in the order of Cr film → M layer 92M2 scraps from the substrate side (note that M1 layer and 2M2
Depending on the layer, a refractive index film layer with an optical thickness of 3λ0/4 (3M layer)
is formed).

This multilayer film surface reflector exhibits the same spectral reflection characteristics as the multilayer film surface reflector of Example 1 shown in FIG. 4, and has excellent anti-glare properties and visibility.

Example 5 FIG. 1(E) is an enlarged cross-sectional view of main parts of another example of the multilayer film surface reflecting mirror of the present invention, in which 4]- is a glass substrate,
42 is a Cr film, 43 is a Rh film, and 44 is an optical film made of S i 02 with a refractive index of 1.46, with an optical thickness of λO/4 (in this example, the wavelength λO of light, which is the center of the design, is 540 nm, so 45 is a refractive index film layer (M1 layer) having an optical thickness of 2λo/4 (270 nm) and made of A1203 with a refractive index of 1.63 (2M2 layer). That is, the multilayer film surface reflecting mirror of this example has a Cr film→R on one side of the glass substrate from the substrate side.
A multilayer film is formed in the order of h film→M1 layer→2M2 layer (the M layer and the 2M2 layer form a refractive index film layer (3M layer) with an optical thickness of 3λo/4).

This multilayer film surface reflecting mirror is shown in FIG.
It exhibits spectral reflection characteristics similar to those of the multilayer film surface reflector, and has excellent anti-glare properties and visibility. It also has high reflectivity.

Example 6 FIG. 1 (F) is an enlarged sectional view of main parts of another example of the multilayer film surface reflecting mirror of the present invention, and in the figure, 51 is a glass substrate;
52 is a Ge film, 53 is a refractive index] -946 S i 02
Optical film thickness λO/4 (In this example, the wavelength λO of light that is the center of the design is 540 nm, so λ
o/4 is 135 nm) refractive index film layer (M1 layer),
54 is a refractive index film layer (2M2 layer) with an optical thickness of 2λo/4 (270n...) made of Al 203 with a refractive index of 1.63.
It is. That is, in the multilayer film surface reflecting mirror of this example, a multilayer film is formed on one side of a glass substrate in the order of Ge film → M1 layer → 2M2 layer from the substrate side (the optical film thickness is 3λ0 by the M1 layer and the 2M2 layer). /4 refractive index film layer (3M layer) is formed).

This multilayer film surface reflector exhibits the same spectral reflection characteristics as the multilayer film surface reflector of Example 3 shown in FIG. 6, and has excellent anti-glare properties and visibility.

Embodiment 7 FIG. 1(G) is an enlarged sectional view of main parts of another embodiment of the multilayer film surface reflecting mirror of the present invention, in which 61 is a glass substrate;
2 is a Cr film, 63 is an Al2O3 film with a refractive index of 1.63, and has an optical film thickness of λO/4 (in this example, the wavelength λ0 of light, which is the center of the design, is 540 nm, and therefore λo/4).
is 135 nm) refractive index film/iJ (M1 layer), 6
4 is the optical film thickness λ made of Ce F 3 with a refractive index of 1°63
O/4 (], 35 nm) refractive index film layer (M27im)
, 65 is the optical film thickness λ consisting of Sj, 02 with a refractive index of 146
It is a refractive index film layer (M3 layer) of O/4 (1350...).

That is, in the multilayer film surface reflecting mirror of this embodiment, a multilayer film is formed on one side of a glass substrate in the order of Cr film → M layer → M2 layer → M3 layer (in addition, M1 layer, M2 layer, and M3 layer).
A refractive index film layer with an optical thickness of 3λo/4 (3M layers are formed) by three layers.

This multilayer film surface reflector exhibits the same spectral reflection characteristics as the multilayer film surface reflector of Example 1 shown in FIG. 4, and has excellent anti-glare properties and visibility.

Example 8 FIG. 1 (H) is an enlarged cross-sectional view of main parts of another example of the multilayer film surface reflecting mirror of the present invention, in which 7]- is a glass substrate,
72 is a Cr film, 73 is a Rh film, 74 is an Al2O3 film with a refractive index of 1.63, and has an optical thickness of λO/4 (in this example, the wavelength of light that is central to the design is 540 nm, so λO /4 is 1350 m> refractive index film layer (
M1 layer), 75 is a refractive index film layer (
76 is a refractive index film layer (M3 layer) having an optical thickness λO/4 (135 nm) and made of 3102 having a refractive index of 1.46. That is, the multilayer film surface reflecting mirror of this embodiment has a Cr film -R, an h film→M1 on one side of a glass substrate from the substrate side.
Layer-M22 minutes A multilayer film is formed in the order of 3 layers (the optical film thickness is 3λ0/4 by the M layer, M2 layer, and Hezuki layer).
refractive index film layer (3M layer) is formed).

This multilayer film surface reflecting mirror is the embodiment 2 shown in FIG.
It exhibits spectral reflection characteristics similar to those of the multilayer film surface reflecting mirror 1, and has excellent anti-glare properties and visibility.

It also has high reflectivity.

Embodiment 9 FIG. 1(I) is an enlarged sectional view of main parts of another embodiment of the multilayer film surface reflecting mirror of the present invention, in which 8]- is a glass substrate, 82 is a Ge film, and 83 is a An optical film made of Al2O3 with a refractive index of 1°63 has a thickness of λo/4 (in this example, the wavelength λ0 of the light that is the center of the design is 540 nm, so λo
/4 is 135 nm) refractive index film layer (M1 layer), 8
4 is the optical film thickness λ made of Ce F 2 with a refractive index of 1°63
o/4 (135 nm) refractive index film layer (M2 layer), 85 is an optical film thickness λO/4 made of Si02 with a refractive index of 1°46
(1350...) is a refractive index film layer (IVI 3 layer). That is, in the multilayer film surface reflecting mirror of this example, multilayer films are formed on one side of a glass substrate in the order of Ge film → M layer → M2 layer → M3 layer from the substrate side (note that M1 layer and M2 layer are separated from each other). M
The three layers form a refractive index film layer (3M layer) with an optical thickness of 3λo/4).

This multilayer film surface reflector exhibits the same spectral reflection characteristics as the multilayer film surface reflector of Example 3 shown in FIG. 6, and has excellent anti-glare properties and visibility.

Embodiment 10 FIG. 1 (, J) is an enlarged sectional view of main parts of another embodiment of the multilayer film surface reflecting mirror of the present invention, in which 91 is a glass substrate;
2 is a Cr film, 93 is an A I 203 film with a refractive index of 1.63, and has an optical film thickness of λO/4 (in this example, the wavelength of light that is central to the design is 5400..., so λo/4
is 1351 m), and 94 is the optical film thickness λO/
4 (135 nm) refractive index film layer (M2 layer), 95 is an optical film thickness λO/4 consisting of A 1203 with a refractive index of 1.63.
(135 nm) refractive index layer (M1 layer). That is, in the multilayer film surface reflecting mirror of this embodiment, a multilayer film is formed on one side of a glass substrate in the order of Cr film → M layer - M2 layer - M1 layer (two Mll and one M2 layer) from the substrate side. The layers form a refractive index film layer (3M layer) with an optical thickness of 3^o/4).

This multilayer film surface reflector exhibits the same spectral reflection characteristics as the multilayer film surface reflector of Example 1 shown in FIG. 4, and has excellent anti-glare properties and visibility.

Example 11 FIG. 1(K) is an enlarged cross-sectional view of main parts of another example of the multilayer film surface reflecting mirror of the present invention, and in the figure, 101 is a glass substrate,
102 is a Cr film, 103 is a Rh film, and 104 is a refractive index of 1.
Optical film thickness λO/4 (in this example, the wavelength λO of the light that is the center of the design is 540 nI)
Il, therefore λo/4 is 135 nm) refractive index film 1 (M1 layer), ]-05 is Ce with a refractive index of 1.63
A refractive index film layer (M2 layer) with an optical thickness of λO/4 (135 nm) consisting of F3, 106 is Al with a refractive index of 1.63.
This is a refractive index film layer (M1 layer) made of 2O3 and having an optical thickness of λo/4 (135 nm). That is, the multilayer film surface reflecting mirror of this example has Cr coated on one side of the glass substrate from the substrate side.
A multilayer film is formed in the order of film → Rh film → M layer → M2 layer → M1 layer (note that two M1 layers and 1,000 M2 layers form a refractive index film layer (3M layer) with an optical thickness of 3λo/4. is formed).

This multilayer film surface reflector exhibits the same spectral reflection characteristics as the multilayer film surface reflector of Example 2 shown in FIG. 5, and has excellent anti-glare properties and visibility. It also has high reflectivity.

Embodiment 12 FIG. 1(L) is an enlarged sectional view of main parts of another embodiment of the multilayer film surface reflecting mirror of the present invention, and in the figure, 111 is a glass substrate;
1]-2 is a Ge film, 113 is an AI with a refractive index of 1.63
Optical film thickness λo/4 consisting of 203 (in this example,
The wavelength λO of the light that is central to the design is 540 nm, so λO/4 is 135 nm).
layer), 114 is a refractive index film layer (M2 layer) made of CeF with a refractive index of 6B and has an optical thickness of λ0/4 (135 nm), ]-15 is an optical film made of AIO with a refractive index of 1.63 A refractive index film layer (IV
11 layers). That is, the multilayer film surface reflecting mirror of this example has a Ge film-M1 layer on one side of the glass substrate from the substrate side.
A multilayer film is formed in the order of M2 layer → M1 layer (note 2
Optical film thickness 3λo/4 with two M-layers and one M-layer
refractive index film layer (3M layer) is formed).

This multilayer film surface reflector exhibits the same spectral reflection characteristics as the multilayer film surface reflector of Example 3 shown in FIG. 6, and has excellent anti-glare properties and visibility.

Even if each layer of the dielectric film in Examples 1 to 12 is replaced with an equivalent film, similar reflection characteristics can be obtained.

Comparative Example FIG. 7 (A>, (B) shows a refractive index layer (3M layer) with an optical thickness of 3λo/4 made of 5i02 with a refractive index of 1.46 in the multilayer film surface reflecting mirror of Example 1 of the present invention. were changed to a refractive index film layer (2M layer) with an optical thickness of 2^0/4 and a refractive index film N (4M layer) with an optical thickness of 4λo/4 using the same material, respectively.
It is an enlarged sectional view of main parts of a multilayer film surface reflecting mirror of a comparative example, in which 121 and 131 are glass substrates, and 122 and 132 are C
The r film 123 is a 2M layer, and 13B is a 4M layer.

In other words, the multilayer film surface reflecting mirror of this comparative example has a Cr film on one side of the glass substrate from the substrate side → 2M! A multilayer film is formed in this order (or 4M layers).

The spectral reflection characteristics of the multilayer surface reflector of this comparative example are shown in Figure 8 (in the figure, the curve (1) is for the case where the 2M layer is on the Cr film, and the curve (2) is for the case where the 2M layer is on the Cr film). 4M layer).

As is clear from FIG. 8, unlike the multilayer surface reflectors of Examples 1 to 12, the multilayer surface reflector of the comparative example has a region 480 where the product of the scotopic specific luminous efficiency and the spectral energy of the headlight is high. -Since the reflectance at 550 nm is high, the anti-glare property is poor, and the reflection at 430 nm to 480 nm (blue) and 580 nm to 700 nm (red), which are blue and red wavelengths to which humans have low brightness sensitivity. Visibility is also poor due to the low rate.

Therefore, in order to obtain a multilayer film surface reflecting mirror with anti-glare properties and visibility, as can be seen from Examples 1 to 12 and Comparative Examples, a metal or semiconductor film and an optical film thickness of 3λo/1 are coated on one side of a glass substrate from the substrate side. It has become clear that it is essential to form the 4 3M layers in this order.

[Effects of the Invention] The multilayer film surface reflecting mirror of the present invention has the following technical effects.

(1) Excellent anti-glare properties.

As is clear from FIGS. 4 to 6, the reflecting mirror of the present invention has a second
Figure, P(λ) x V'(λ) shown by curve (3)
from 480 nm to 600 nm, which corresponds to the region with large values of
It has a low reflectance at nm, so it has excellent anti-glare effects.

(11) Excellent visibility.

As shown in Figures 4 to 6, the reflector of the present invention has a low reflectance in the wavelength range necessary for anti-glare, and a high reflectance in other wavelength ranges, ensuring excellent visibility. .

In addition, the reflector of the present invention has good brightness sensitivity in the green region (4
90-580nm) in the blue region (400-48nm)
0 nm) and the red region (590 to 750 nm), and as a result, it sensitizes blue and red colors to which the eye has low sensitivity, which also has the advantage of improving color discrimination (contrast).

(iii) Excellent decorative and fashionable properties.

As a result of pursuing anti-glare properties and visibility, the reflecting mirror of the present invention has a magenta-tinged reflected color.

This magenta color gives the mirror a sense of luxury and allows it to be differentiated from other reflective mirrors.

(iv) Excellent productivity and cost efficiency.

In manufacturing the reflecting mirror of the present invention, there are advantages such as a small number of layers of the dielectric film formed and the ability to form the dielectric film and the metal or semiconductor film by the same film forming method. Therefore, unlike the case of the reflecting mirror disclosed in JP-A-63-165805, which has a large number of dielectric multilayer films and requires painting and baking a light-absorbing film, this method has excellent productivity and cost efficiency. ing.

In summary, according to the present invention, a multilayer film surface reflecting mirror is provided which has advantages such as anti-glare properties, visibility, decorative properties, and harmful ray blocking properties despite having a small number of layers.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of the main parts of the multilayer film surface reflecting mirror of the present invention.
Figure 2 shows the scotopic specific luminous efficiency of the human eye, the spectral energy characteristics of a car headlamp, and the spectral energy characteristics of a car headlamp perceived by the human eye, which is the product of these. 4, 5, and 6 are spectral reflection characteristic diagrams of the mirror of the present invention. FIG. FIG. 8 is a spectral reflection characteristic diagram of a reflecting mirror of a comparative example.

Claims (1)

[Claims] 1. A metal or semiconductor film is provided on one side of the base material, and one or more refractive index material layers are further formed on the metal or semiconductor film, and the optical film thickness is 3λ.
_0/4 (λ_0 is the wavelength of light that is the center of the design)
A multilayer film surface reflecting mirror characterized by being provided with a dielectric film of. 2. The multilayer surface reflecting mirror according to claim 1, wherein the dielectric film having an optical thickness of 3λ_0/4 is formed of one refractive index material layer. 3. The dielectric film with an optical thickness of 3λ_0/4 is composed of one type of refractive index material layer with an optical thickness of λ_0/4 and an optical thickness of 2
The multilayer film surface reflecting mirror according to claim 1, wherein the multilayer film surface reflecting mirror is formed of a layer of another type of refractive index material having a refractive index of λ_0/4. 4. The dielectric film with an optical thickness of 3λ_0/4 is composed of one type of refractive index material layer with an optical thickness of λ_0/4 and an optical thickness of λ_0/4.
Optical film thickness is λ_0/ with another type of refractive index material layer of _0/4
4. The multilayer film surface reflecting mirror according to claim 1, wherein the multilayer film surface reflecting mirror is formed of a layer of a refractive index material of another type. 5. The dielectric film having an optical thickness of 3λ_0/4 has one type of refractive index material layer having an optical thickness of λ_0/4, and another type of refractive index material layer having an optical thickness of λ_0/4 provided on both sides thereof. 2. The multilayer film surface reflecting mirror according to claim 1, wherein the refractive index material layers provided on both sides are of the same type. 6. The multilayer film surface reflecting mirror according to claims 1 to 5, wherein the metal or semiconductor film is formed of one or more metal or semiconductor layers.