JPH012003A - Metal-based dichroic reflector - 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] [Technical Field] This invention relates to a dichroic reflector mainly used in lighting equipment. This technology relates to a technology that prevents the temperature of a reflecting mirror from rising by emitting heat.

[Background technology]

Lighting equipment using incandescent lamps or halogen lamps as a light source has the disadvantage that unnecessary infrared rays emitted from these light sources cause discomfort to the human body and cause thermal damage to objects to be irradiated.

In order to overcome these difficulties, a dichroic reflector is used in which a dichroic film formed by alternately laminating two types of dielectric thin films having different refractive indexes is formed on the surface of a glass substrate.

The dichroic film formed on the surface of this dichroic reflector selectively transmits infrared rays emitted from the light source and reflects only visible rays.
It removes infrared rays from the irradiated light to reduce its harmful effects. Further, according to this dichroic film, it is also possible to adjust the color of reflected light to some extent.

However, as mentioned above, the base material of such dichroic reflectors is made of glass because they need to transmit infrared rays, so they have problems such as being vulnerable to mechanical and thermal shocks, being easily damaged, and being heavy. . In addition, the molding conditions for glass are difficult;
(b) There are also problems such as being limited to relatively simple shapes.

Therefore, in order to improve these drawbacks, a dichroic reflector using a metal such as aluminum as a base material was developed. This is made by forming an infrared absorbing layer on the surface of a metal base material by a method such as painting or vapor deposition, and further forming the above-mentioned dichroic film thereon. In the dichroic reflector made of this metal base, the infrared rays that are transmitted and emitted by conventional glass base materials are absorbed by the infrared absorbing layer and removed from the irradiated light. The above problem is solved because a metal that is easy to mold, lightweight, and strong against impact can be used.

However, in such a reflecting mirror made of a metal base material, infrared rays are absorbed by the infrared absorbing layer and are not emitted, so that the temperature of the reflecting mirror itself increases during use. When the temperature of the reflector increases in this way, a problem arises in that the cord of the lamp, which is the light source, is destroyed by the heat. For this reason, with such a reflecting mirror made of a metal base material, special consideration must be taken in designing the lighting fixture so that parts such as lead wires do not come into contact with the reflecting mirror.

There is also the problem that each layer on the surface of the base material peels off from the base material due to the heat accompanying the temperature increase of the reflecting mirror.

[Purpose of the invention]

This invention was made in view of the above circumstances, and
Metal-based dichroic reflection allows the use of easily processable metals such as aluminum as the base material, does not cause temperature rise during use, efficiently cuts unnecessary infrared rays, and efficiently reflects visible light. The purpose is to provide a mirror.

[Disclosure of the invention]

In order to achieve the above object, the present invention provides, on a metal base material,
A metal-based dichroic reflector on which a dichroic film is formed by alternately laminating two types of dielectric thin films with different refractive indexes, the metal base material having infrared absorbing layers on both the front and back surfaces thereof. The gist is a metal-based dichroic reflector that is characterized by:

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the metal-based dichroic reflector of this embodiment has infrared absorbing layers 2.2 formed on both the front and back surfaces of a substantially bowl-shaped metal base 1 that holds a lamp L as a light source in the center. A dichroic film 3 is laminated on an infrared absorbing layer 2 on the front side (inside the bowl).

As the metal base material 1, aluminum, an alloy thereof, or the like is preferably used from the viewpoint of workability and the like.

The metal base material 1 is obtained by processing these metal plate materials by a processing method such as press molding, as in the past, but of course, it can also be created by a method other than press molding.

The infrared absorbing layer 2.2 formed on both the front and back surfaces of the metal base material 1 and made of a substance with high infrared absorption rate may be the same as that used in a conventional reflecting mirror made of a metal base material. As the absorption layer 2, AItos is used as before.
, NiO, Cu*0SSiOtx Zr01 and S
*Membranes such as now are used. The infrared absorbing layers formed on both sides of the metal base material 1 may be the same or may be different from each other.

The method for forming the infrared absorbing layer 2 is not particularly limited, and a normal method for forming a thin film made of these materials may be employed. For example, a physical vapor deposition method such as a vacuum evaporation method, a sputtering method, an ion blating method, or a chemical vapor deposition method such as a CVD method may be used, or an organic metal compound that becomes the metal oxide by baking may be used. A method may be used in which a coating film is formed on the surface of the metal base material 1 and fired to obtain a thin film of the metal oxide, and the metal of the metal base material 1 and the infrared absorbing layer 2 are the same. In some cases, the infrared absorbing layer 2 can also be obtained by chemically or physically oxidizing the surface of the base material 1.

Although the film thickness of the infrared absorbing layer 2 is not particularly limited in the present invention, it is preferably within the range of about 1 to 10x.

This is because if the film thickness is less than 1μ, a sufficient infrared absorption effect cannot be obtained, and if it exceeds 10m, there will be no close contact between the base material 1 and the infrared absorption layer 2, or between the infrared absorption layer 2 and the dichroic film 3. This is because there is a risk that sexual performance may be significantly reduced.

Needless to say, the above-mentioned compounds forming the infrared absorbing layer 2 have a high infrared absorption rate, but this also means that these compounds have a high infrared emissivity. This invention utilizes this property of the above compound. That is, the dichroic film 3
The infrared absorbing layer N2 formed under the base material 1 absorbs infrared rays as in the conventional case, and the infrared absorbing material N2 formed on the opposite side of the base material 1 emits the infrared rays, thereby preventing the temperature of the base material 1 from rising.

The dichroic film 3 formed on one of the infrared absorbing layers 2 may be the same as the conventional one.

That is, a high refractive index dielectric thin film (refractive index n-2, about 0 to 2.6) made of metal oxides such as Ties, Cent, ZrOt, etc. and ZnS, and metal oxides such as 5iO-1Al*Ot. A dielectric thin film with a low refractive index (refractive index n = 1.
3 to 1.6) are alternately laminated and molded. It is sufficient that the two electric conductor thin films have a thickness of about 1/4 of the target wavelength λ, that is, about λ/4.

These thin films can be formed by, for example, physical vapor deposition methods such as vacuum evaporation, sputtering, and ion blating, or CVD.
It can be formed by a chemical vapor deposition method such as a method. Alternatively, a method may be used in which a coating film of an organometallic compound that becomes the dielectric is formed on the surface of the metal base material 1 by firing, and then the thin film of the dielectric is obtained by firing.

During the formation, the substrate may be heated above room temperature, because generally speaking, the higher the substrate temperature, the higher the hardness of the formed thin film and the better its durability. However, if the base material temperature is too high, workability may deteriorate.
Productivity, etc. may deteriorate. Therefore, the substrate temperature is preferably about room temperature to 300°C.

As described above, the dichroic reflector of the present invention has the characteristics of conventional metal-based reflectors, namely, it is lightweight and easy to process, and is resistant to mechanical and thermal shocks and has a complex shape. It is now possible to obtain a metal-based dichroic reflector that maintains the advantage of being able to form a dichroic mirror without increasing its temperature during use.

Therefore, there is no need to take special consideration to this temperature rise when designing, and there is no fear that each layer on the surface of the base material will be destroyed by heat. Although the mirror has been described only based on the above embodiments, the present invention is not limited to the above embodiments.

For example, the shape of the base material 1 is not limited to the arm shape shown in the figure,
The number of dichroic film layers is also not limited to the illustrated embodiment. The use of dichroic reflectors is not limited to lighting equipment.

In short, it is a metal-based dichroic reflector in which a dichroic film is formed by alternately laminating two types of dielectric thin films having different refractive indexes on a metal base material, and the metal base material is Other configurations are not particularly limited as long as both sides have infrared absorbing layers.

Next, examples of the present invention will be described together with comparative examples.

(Example 1) Aluminum base material 1 formed into a bowl shape by press molding
On the other hand, alumite treatment was performed to form a film thickness of 3n on both the front and back sides.
Affix, a film was formed and the infrared absorption WI was set to 2.2. On the infrared absorbing layer 2 on the inside of the arm, which is the surface of the base material, 5
Electron beam evaporation is performed in a vacuum of 10-' Torr,
A dichroic film 3 was formed by alternately laminating a TiO□ film 3a, which is a dielectric thin film with a high refractive index, and an MgF* film, which is a dielectric thin film with a low refractive index, to create a metal-based dichroic reflector. The layer structure of the obtained metal-based dichroic reflector is shown in Figure 2+8).

FIG. 3 shows the reflectance distribution of the metal paced dichroic reflector thus produced.

As shown in the figure, the metal-based dichroic reflector of this example has an average reflectance of about 90% for visible light (400 to 700 nm), and an average reflectance of longer wavelength infrared rays of about 20%. It was possible to cut 80% of the

This metal-based dichroic reflector was attached to a spotlight, the light source was turned on, and the temperature of the reflector surface was measured, but no temperature exceeded 250°C. Furthermore, the layers formed on the surface of the base material did not peel off.

(Example 2) Ti1t and 5t0
TiO2 film (high refractive index dielectric thin film 3a) formed by applying and baking a paint containing an organometallic compound of No. 8
A metal-based dichroic reflector having the layer structure shown in FIG. 2(a) was prepared in the same manner as in Example IN1 except that the 5iOtI odor (low refractive index dielectric thin film 3b) was used.

The resulting metal-based dichroic reflector is capable of transmitting visible light (
The average reflectance for infrared rays (400 to 700 nm) was about 90%, and the average reflectance for infrared rays with longer wavelengths was about 20%, meaning that 80% of infrared rays could be cut.

This metal-based dichroic reflector was attached to a spotlight, the light source was turned on, and the temperature of the reflector surface was measured, but the temperature did not exceed 250°C. Furthermore, the layers formed on the surface of the base material did not peel off.

(Example 3) Aluminum base material 1 formed into a bowl shape by press molding
was immersed in an alcohol solution of zircon isopropinate, pulled out from the solution and dried to form a coating film. This operation was repeated until the coating film had a predetermined thickness, and then baking was performed to form a Zr0t film with a thickness of 3 μm on both the front and back surfaces of the base material, thereby forming an infrared absorbing layer 2.2. After that, the same operation as in Example 1 was carried out to form a Ti dielectric thin film with a high refractive index.
1t film 3a and MgFz which is a low refractive index dielectric WI# film
The dichroic film 3 is formed by alternately stacking the films.
A metal-based dichroic 7 reflector having the layer structure shown in FIG. 2(a) was prepared.

The resulting metal-based dichroic reflector is capable of transmitting visible light (
400-b 0%, average reflectance of infrared rays with longer wavelengths is approximately 20%
It was able to cut out 80% of infrared rays.

This metal-based dichroic reflector was attached to a spotlight, the light source was turned on, and the temperature of the reflector surface was measured, but the temperature did not exceed 25 l.In addition, each layer formed on the base material surface peeled off. There was no such thing.

(Example 4) A metal-based dichroic reflecting mirror having the layer structure shown in FIG. 2(a) was produced in the same manner as in Example 3 except that the dichroic film 3 was formed in the same manner as in Example 2.

The resulting metal-based dichroic reflector is capable of transmitting visible light (
400 to 700 rv) was approximately 90%, and the average reflectance of infrared rays with longer wavelengths was approximately 20%, meaning that 80% of infrared rays could be cut.

This metal-based dichroic reflector was attached to a spotlight, the light source was turned on, and the temperature of the reflector surface was measured, but the temperature did not exceed 250°C. Furthermore, the layers formed on the surface of the base material did not peel off.

(Example 5) Aluminum base material formed into a bowl shape by press molding
Then, electron beam evaporation was performed in a vacuum of 5 x 10-'' Torr to form a ZrOx film with a thickness of 3 nm on both the front and back surfaces, forming an infrared absorbing layer 2.2. The high refractive index dielectric thin film rtol
A dichroic 1!13 is formed by alternately laminating Aoi 3a and a MgF film, which is a dielectric thin film with a low refractive index.
A metal-based dichroic reflector with the layered structure shown in Figure 2+8) was created.

The resulting metal-paced dichroic reflector is capable of transmitting visible light (
The average reflectance for infrared rays (400 to 700 ns+) was about 90%, and the average reflectance for infrared rays with longer wavelengths was about 20%, meaning that 80% of infrared rays could be cut.

This metal pace dichroic reflector was attached to a spotlight, the light source was turned on, and the temperature of the reflector surface was measured, but the temperature did not exceed 250°C. Furthermore, the layers formed on the surface of the base material did not peel off.

(Comparative example) Aluminum base material 1 formed into a bowl shape by press molding
A black paint was applied by spraying to the surface side (inner side of the bowl) and dried to form an infrared absorbing layer 2' having a thickness of 5 nm and consisting of a black paint film. After that, the same operation as in Example 1 was performed to form the dichroic film 3 by alternately laminating the TiOJ film 3a, which is a dielectric thin film with a high refractive index, and the MgFt film, which is a dielectric thin film with a low refractive index. A metal-based dichroic reflector having the layer structure shown in FIG. 2(b) was fabricated.

The resulting metal-paced dichroic reflector is capable of transmitting visible light (
The average reflectance of infrared rays (400 to 700 n-) was about 90%, and the average reflectance of infrared rays with longer wavelengths was about 20%, meaning that 80% of infrared rays could be cut.

When this metal pace dichroic reflector was attached to a spotlight, the light source was turned on, and the temperature of the reflector surface was measured, it reached 350 degrees Celsius, and some of the layers formed on the base material surface peeled off. .

〔Effect of the invention〕

The metal-paced dichroic reflector of the present invention is as described above, and has a dichroic film formed by alternately laminating two types of dielectric thin films having different refractive indexes on a metal substrate. It is a mirror, and the metal base material has an infrared absorbing layer on both the front and back surfaces, and the infrared rays absorbed by the infrared absorbing layer on the front side can be emitted from the infrared absorbing layer on the back side.
Metals such as aluminum, which are easy to process, can be used as the base material, and the temperature does not rise during use, and unnecessary infrared rays can be efficiently cut and visible light can be efficiently reflected. There is.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view and partially enlarged view showing an embodiment of the metal pace dichroic reflector of the present invention, and FIG. 2 is an N configuration explaining the layer structure in the embodiment of the invention 2 (bl is a layer structure diagram explaining the layer structure in a comparative example, and FIG. 3 is a graph showing an example of the reflectance distribution in an example. 1... Metal base material 3a, 3b.・Dielectric thin film 3・
・・Gucroic film 2・・Infrared absorbing layer agent
Patent Attorney Takehiko Matsumoto Figure 1

Claims (2)

[Claims] (1) A metal-based dichroic reflector in which a dichroic film formed by alternately laminating two types of dielectric thin films having different refractive indexes on a metal base material, wherein the metal base material is A metal-based dichroic reflector characterized by having infrared absorbing layers on both the front and back sides. (2) Infrared absorption layer is Al_2O_2, NiO, Cu_
2. The metal-based dichroic reflector according to claim 1, which is a thin film formed of at least one selected from the group consisting of 2O, SiO_2, ZrO_2 and SnO_2.