JPH117816A - Light absorber, reflector and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the film thickness to shorten the film forming time, and also minimize the cleaning frequency of a film forming equipment to reduce the cost. SOLUTION: A light absorber is provided by forming a light absorbing film 2 comprising a first thin film 2a mainly composed of titanium of a titanium compound and a second thin film 2b mainly composed of chromium or a chromium compound and having a thickness about 2 times the first thin film 2a on a base 1. Further, a reflector is provided by forming a light selectively reflecting film 3 for reflecting a specified wavelength band light which consists of a multilayer interference film on the light absorbing film 2. The optical film thickness of the first thin film 2a to the second thin film 2b is set to about 1:2, whereby the optical film thickness of the light absorbing film 2 can be diminished while keeping a sufficient light absorption effect although the reason is not clear, the film forming time can be shortened, and the cleaning frequency of a film forming equipment can be diminished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light absorber, a reflector using the same, and a lighting device.

[0002]

2. Description of the Related Art A reflector comprising a multi-layer interference film called a dichroic mirror and having a light selective reflection film which reflects visible light and transmits heat rays is a large amount of heat rays emitted from a light source such as a light bulb together with visible light. Can be removed as much as possible so that only visible light can be reflected. Therefore, when used as a reflector of a lighting fixture such as a spotlight, theoretically, about 80% of heat rays can be removed.

[0003] Therefore, in store lighting, it is often used when lighting products while protecting them from heat rays.

By the way, a reflector provided with a light selective reflection film composed of a multilayer interference film includes one using glass as a base,
Some use metals.

[0005] A reflector using a metal base is suitable for a large reflector or a reflector of an irregular shape.

However, in a reflector provided with a light selective reflection film using a metal substrate, most of the heat rays that have once passed through the light selective reflection film are reflected on the surface of the substrate and again form the multilayer interference film from the back side. There is a problem that the light is transmitted and irradiated to the illuminated body side.

Therefore, a heat ray absorbing film is formed between the substrate and the multilayer interference film. As a heat ray absorbing film, a black paint layer,
It is known to use a black dye layer, a black anodized film, or a composite layer of a titanium-based thin film and a chromium-based thin film.

[0008]

However, there is a problem that a part of the heat ray is reflected on the surface of the heat ray absorbing film, and then passes through the visible light reflecting / heat ray transmitting film again to return. For this reason, the heat ray removal rate decreases.

[0009] Among the various heat ray absorbing films described above, a composite layer of a titanium-based thin film and a chromium-based thin film has a property of absorbing light in a wide wavelength range from heat rays to visible light. Body. By using this light absorber as a heat ray absorber as described above, the problem of reflection of heat rays on the surface of the heat ray absorption film can be solved within a practical range, and the heat ray removal rate has been improved.

However, in a conventional light absorbing film composed of a composite layer of a titanium-based thin film and a chromium-based thin film, the titanium-based thin film and the chromium-based thin film are formed to have substantially the same optical film thickness.

For this reason, in order to perform a sufficient heat ray absorbing action, it is necessary to increase the optical film thickness.

For this reason, film formation requires a long time of about several tens of minutes.

[0013] This also increases the frequency of cleaning of the film-forming equipment, which increases the cost.

According to the present invention, the optical film thickness can be reduced, the film forming time can be shortened, and the frequency of cleaning the film forming equipment can be reduced, so that a low-cost light absorber, a reflector using the light absorber, and a lighting device. It is intended to provide a device.

[0015]

According to the first aspect of the present invention, there is provided a light absorber comprising: a base; a first thin film formed of titanium as a main component and a first thin film formed of chromium on a surface of the base;
And a light absorbing film including a second thin film having an optical thickness about twice that of the first thin film formed on the thin film.

In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.

The base will be described.

The substrate may be made of a rigid material such as metal, synthetic resin, glass and ceramics. However, a material having good heat dissipation is effective for dissipating the heat absorbed by the substrate. . In order to dissipate the heat rays, the temperature of the substrate is increased by the absorbed heat, and thus any one of radiation, convection, or conduction may be used or a combination of a plurality of embodiments.

However, the shape and structure of the substrate are free. This is because if the composite layer of the present invention is formed using a member that wants to absorb heat rays as a substrate, the heat rays can be favorably absorbed.

Next, the light absorbing film will be described.

In the first thin film, that the main component is titanium means that titanium metal is the main component, and that the subcomponent is free. That is, it is permissible to mix alumina Al ₂ O ₃ , silica SiO _{2, and the} like as subcomponents in order to adjust the refractive index of the thin film, improve the adhesion and the durability, and the like.

In the second thin film, that the main component is chromium means that the main component is chromium metal, and the subcomponent is free. The sub-components are the same as in the first thin film.

It is important that the optical thickness of the second thin film is about twice the optical thickness of the first thin film.

The optical film thickness is a value obtained by multiplying the mechanical film thickness of the film by the refractive index of the constituent material of the film.

The term "approximately" means that a certain amount of error is allowed within a range that does not affect the essence of the present invention, and in that sense, it means a range up to ± 15%.

Further, when forming the first thin film and the second thin film, if necessary, a plurality of layers of each film may be alternately layered.

In the present invention, the ratio of the optical film thickness of the first thin film to the second thin film is set to about 1: 2 in the light absorbing film. Even if the overall optical film thickness is reduced, the absorptivity of heat rays and visible light is as high as 80% or more, and thus the heat ray reflectivity is 20%.
Therefore, the film formation time can be shortened, and the frequency of cleaning the film formation equipment can be reduced.

Further, in the present invention, since it is possible to absorb heat rays satisfactorily, the use as a heat ray absorbing film is as described above. In addition, it can sufficiently meet expectations for applications mainly intended for absorption of visible light. Of course, it is needless to say that it is particularly effective when it is desired to absorb heat rays and also shield visible light as much as possible.

A light absorber according to a second aspect of the present invention comprises a substrate, a first thin film mainly composed of a titanium compound and formed on the surface of the substrate, and a first thin film mainly composed of a chromium compound on the first thin film. And a light-absorbing film including a second thin film having an optical thickness about twice that of the formed first thin film.

Titanium compounds are not metallic titanium,
It means oxides and nitrides of titanium.

Similarly, the chromium compound means not chromium metal but an oxide of chromium.

The sub-components are the same as in claim 1.

The meaning of about is the same as in claim 1.

Thus, also in the present invention, a good light absorbing action is performed as in the first aspect.

According to a third aspect of the present invention, in the light absorber of the first or second aspect, the titanium compound is titanium oxide and / or titanium nitride; and the chromium compound is chromium oxide. Features.

The present invention specifically illustrates practical materials as accessory components.

A reflector according to a fourth aspect of the present invention is a reflector comprising: a base; a first thin film mainly composed of titanium and formed on the surface of the base; and a first thin film mainly composed of chromium and formed on the first thin film. A light absorbing film including a second thin film having an optical thickness about twice that of the first thin film; and a light selective reflection formed of a multilayer interference film formed on the second thin film and reflecting light in a specific wavelength range. A membrane;
It is characterized by having.

The present invention reflects light in a specific wavelength range, for example, visible light, and transmits light in other wavelength ranges, for example, heat rays,
This is a reflector that allows the base to absorb light in other wavelength ranges, for example, heat rays, and dissipates the absorbed heat to the back side of the base.

The light absorbing film is composed of a first layer mainly composed of titanium and a second layer mainly composed of chromium.

As the light selective reflection film, a film having a known configuration can be used. For example, titanium dioxide TiO
₂ and silicon dioxide SiO ₂ or magnesium fluoride M
It is possible to use a thin film having a high or low refractive index, such as gF ₂ and silicon dioxide SiO ₂ , formed by alternately stacking several to several tens of layers.

Thus, in the present invention, light of a specific wavelength range, for example, visible light, of the light rays incident on the reflector is reflected by the light selective film and irradiated in a desired direction. The heat ray is transmitted through the light selective reflection film, is incident on the light absorbing film and is absorbed, and is further transferred to the substrate to raise the temperature of the substrate. However, the heat of the substrate is mainly radiated from the back side by radiation and convection.

In the present invention, the specific wavelength region light is not limited to visible light, but may be, for example, ultraviolet light. In addition, even if the light is visible light or ultraviolet light, it can also reflect color light in a specific narrow wavelength range.

According to a fifth aspect of the present invention, there is provided a reflector comprising: a base; a first component formed of a titanium compound and formed on a surface of the base.
A light absorbing film including a second thin film having a thickness twice as large as the first thin film formed on the first thin film and having a main component formed of a chromium compound; and a multilayer interference film. And a light selective reflection film formed on the light absorption film.

In the present invention, the light absorbing film is basically the same as claim 4 except that the first layer has a titanium compound as a main component and the second layer has a chromium compound as a main component.

A reflector according to a sixth aspect of the present invention is the reflector according to the fourth or fifth aspect, wherein the surface of the base has a quadratic curved surface shape.

The present invention is suitable for lighting equipment and other lighting devices mainly used in combination with an almost point light source such as an incandescent light bulb since the reflector has a rotating quadric surface shape.

The reflector according to the invention of claim 7 is the reflector according to any one of claims 4 to 6, wherein the titanium compound is titanium oxide and / or titanium nitride; and the chromium compound is chromium oxide; It is characterized by:

The present invention specifically illustrates practical materials as accessory components.

According to an eighth aspect of the present invention, there is provided an illuminating device, comprising: an illuminating device main body; a reflector according to any one of claims 4 to 7 mounted on the illuminating device main body; And a light source provided in the apparatus main body.

In the present invention, the lighting device is applied to any device that uses the light emitted from the light source for some purpose. Therefore, lighting devices such as spotlights and downlights, optical fiber irradiation devices, ultraviolet irradiation devices, display devices, and sign devices may be used.

[0051]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual sectional view showing an embodiment of the light absorber of the present invention.

In the figure, reference numeral 1 denotes a substrate, and 2 denotes a light absorbing film.

The base 1 is an aluminum plate.

The light absorbing layer 2 includes a first thin film 2a and a second thin film 2b.

The first thin film 2a is composed mainly of titanium.

The second thin film 2b is composed mainly of chromium, and its thickness is about twice the first thickness.

FIG. 2 is a graph showing the reflectance distribution of the light absorbing film in one embodiment of the light absorber of the present invention shown in FIG. 1 in comparison with the reflectance of the substrate.

In the figure, the horizontal axis represents the wavelength (nm) and the vertical axis represents the reflectance (%).

The curve A indicates that the optical thickness of the first thin film 2a of the light absorbing film 2 is 91 nm and the optical thickness of the second thin film 2b is 18 nm.
It is a reflectance distribution of the Example of 2 nm.

Curve B also shows that the optical thickness of the first thin film 2a is 90 nm and the optical thickness of the second thin film 2b is 180 nm.
5 is a reflectance distribution of an example in nm.

Curve C also shows that the optical thickness of the first thin film 2 is 89.6 nm and the optical thickness of the second thin film 2b is 17
It is a reflectance distribution of the Example of 9 nm.

Curve D is the reflectance distribution of aluminum of the substrate 1.

As is clear from FIG. 2, when the heat rays to be removed in the wavelength range of 1200 to 2000 nm are slightly more than 200 nm near 200 nn in the case of the curve C.
Although it exceeded 0%, a good low reflectance distribution was exhibited in all cases. Low reflectance indicates good absorption of heat rays.

On the other hand, it can be seen that only the aluminum of the substrate 1 reflects heat rays by 90% or more.

FIG. 3 is a conceptual sectional view showing a first embodiment of the reflector of the present invention.

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the light absorbing film 2 of the light absorber shown in FIG.
And the light selective reflection film 3 is formed on the light absorption film 2 '.

The light absorbing film 2 ′ has a structure in which the first thin film 2 a ′ is made of a material containing titanium dioxide TiO ₂ as a main component.
Is made of a material mainly composed of chromium oxide Cr ₂ O ₃ .

The light selective reflection film 3 is formed by alternately laminating about 10 thin films mainly composed of titanium oxide and thin films mainly composed of silicon dioxide.

In the figure, reference numeral 1a denotes a light source insertion hole formed at the top of the base 1.

FIG. 4 is a sectional view showing a reflector according to a second embodiment of the present invention.

In the figure, the same parts as those in FIG. 3 are denoted by the same reference numerals, and the description is omitted.

The present embodiment is different in that the reflector has a paraboloid of revolution.

FIG. 5 is a partially sectional front view showing a spotlight which is an embodiment of the illumination device of the present invention.

In the figure, 4 is a spotlight body, 5
Is a reflector, and 6 is a light source.

The spotlight body 4 includes a base 4a, a hinge 4b, an arm 4c, a socket 4d, a reflector protection cover 4e, and a front transparent cover 4f.

The base 4a has a function of attaching to the attachment surface 7 such as a ceiling.

The hinge 4b is provided on the base 4a, and can set the arm 4c in a desired direction.

The socket 4d is fixed to the tip of the arm 4c.

The reflector protection cover 4e is integrally formed around the socket 4d, and houses the reflector 5 therein.

The translucent cover 4f is made of a transparent glass plate, and is attached to the opening end of the reflector protection cover 4e.

The light source 6 is mounted by screwing the base into the socket 4d, and is disposed at a substantially focal position of the reflector 5.

[0084]

According to the first to third aspects of the present invention, the optical characteristics of the second thin film mainly containing chromium or a chromium compound are different from those of the first thin film mainly containing titanium or a titanium compound. By doubling the film thickness, the optical film thickness of the light-absorbing film is reduced while maintaining a sufficient light absorbing action, thereby shortening the film forming time and significantly reducing the frequency of cleaning the film forming equipment. Thus, a low-cost light absorber can be provided.

According to the first aspect of the present invention, it is possible to provide a light absorber provided with a light absorbing film in which the first thin film contains titanium as a main component and the second thin film contains chromium as a main component. .

According to the second aspect of the present invention, there is provided a light absorber provided with a light absorbing film in which the first thin film contains a titanium compound as a main component and the second thin film contains a chromium compound as a main component. Can be.

According to the third aspect of the present invention, it is possible to provide a light absorber in which the types of the titanium compound and the chromium compound are specifically defined.

According to each of the fourth to seventh aspects of the present invention, the optical absorption of the second thin film containing chromium or a chromium compound as the main component is different from that of the first thin film containing the titanium or titanium compound as the main component. By doubling the target film thickness, the optical film thickness of the light-absorbing film is reduced while maintaining a sufficient light absorbing action, thereby shortening the film forming time and significantly reducing the frequency of cleaning the film forming equipment. Thus, it is possible to provide a reflector provided with a light selective reflection film made of a low-cost multilayer interference film.

According to the fourth aspect of the present invention, it is possible to provide a reflector including a light absorbing film in which the first thin film contains titanium as a main component and the second thin film contains chromium as a main component.

According to the fifth aspect of the present invention, it is possible to provide a reflector including a light absorbing film in which the first thin film mainly contains a titanium compound and the second thin film mainly contains a chromium compound. it can.

According to the sixth aspect of the present invention, it is possible to provide a reflector in which the types of the titanium compound and the chromium compound are specifically defined.

According to the seventh aspect of the present invention, it is possible to provide a reflector which has a revolving quadratic curved surface shape and is suitable for a lighting device such as a lighting fixture having a point light source.

According to the invention of claim 8, in addition to claim 4,
It is possible to provide a lighting device having the effects of the first to sixth aspects.

[Brief description of the drawings]

FIG. 1 is a conceptual cross-sectional view showing one embodiment of a light absorber of the present invention.

FIG. 2 is a graph showing the reflectance of a light absorbing film in one embodiment of the light absorber of the present invention shown in FIG. 1 while comparing it with the reflectance of a substrate.

FIG. 3 is a conceptual sectional view showing a first embodiment of the reflector of the present invention.

FIG. 4 is a sectional view showing a second embodiment of the reflector of the present invention.

FIG. 5 is a partial cross-sectional front view showing a spotlight in one embodiment of the lighting device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Absorbing film 2a ... 1st thin film 2b ... 2nd thin film 3 ... Light selective reflection film

Claims (8)

[Claims] A first thin film formed mainly on titanium and formed on the surface of the base; and approximately twice as large as a first thin film formed mainly on chromium and formed on the first thin film. A light absorbing film including a second thin film having an optical thickness of: A first thin film formed on the surface of the base material, the first thin film formed of a chromium compound and formed on the first thin film; A light-absorbing film including a second thin film having twice the optical film thickness. 3. The light absorber according to claim 2, wherein the titanium compound is titanium oxide and / or titanium nitride; and the chromium compound is chromium oxide. 4. A substrate and a first thin film formed on the surface of the substrate, the main component being titanium, and approximately twice as large as a first thin film formed on the first thin film, the main component being chromium. A light absorbing film including a second thin film having an optical film thickness of: and a light selective reflection film formed of a multilayer interference film and formed on the second thin film and reflecting light in a specific wavelength range. A reflector, characterized in that: 5. A substrate comprising: a first thin film composed mainly of a titanium compound and formed on the surface of the substrate; and a first thin film composed mainly of a chromium compound and formed on the first thin film. A light absorbing film including a second thin film having twice the optical film thickness; and a light selective reflection film formed of a multilayer interference film and reflecting light in a specific wavelength region formed on the light absorbing film. A reflector, characterized in that: 6. The reflector according to claim 4, wherein the surface of the base has a quadratic curved surface shape. 7. The reflector according to claim 5, wherein the titanium compound is titanium oxide and / or titanium nitride; and the chromium compound is chromium oxide. 8. A lighting device body; a reflector according to any one of claims 4 to 7 mounted on the lighting device body; and a light source disposed on the lighting device body so that radiation is incident on the reflector. And a lighting device comprising: