JP2021157961A - Thermal radiant light source - Google Patents

Abstract

To provide a thermal radiation light source that can be installed with a substrate and a thermal radiation layer exposed to the atmosphere, has a large emissivity in a setting region set in a wavelength range of 8 μm or less, and can simplify the configuration.SOLUTION: A thermal radiation layer N and a substrate K formed of a cantal alloy that heats the thermal radiation layer N are laminated, and the thermal radiation layer N is configured in a state in which a radiation control unit Na having a MIM laminated portion M that positions a transparent oxide layer R for resonance formed of a transparent oxide between the substrate K and a platinum layer P and a transparent oxide layer Nb for radiation formed of transparent oxide are laminated in a form in which the radiation control unit Na and the transparent oxide layer Nb for radiation are located close to the substrate K in this order, and the thickness of the transparent oxide layer R for resonance is such that a set region set in a wavelength region of 8 μm or less is set as a resonance wavelength region.SELECTED DRAWING: Figure 1

Description

The present invention relates to a thermal radiant light source in which a thermal radiant layer and a substrate for heating the thermal radiant layer are laminated.

Such a heat radiation light source radiates radiant light for heating an object to be heated from the heat radiation layer by heating the heat radiation layer to a high temperature state on a substrate.
As such a heat radiation light source, a substrate and a heat radiation layer are arranged in a sealed state inside a sealing tube formed of a translucent airtight member such as quartz glass, and the inside of the sealing tube is put into a vacuum state. Alternatively, there is a sealing tube in which an inert gas such as nitrogen gas is sealed (see, for example, Patent Document 1).

In Patent Document 1, the substrate is made of a refractory metal such as tungsten that generates heat when a current is passed, and the thermal radiant zone is formed of a metal layer such as tantalum or molybdenum. By arranging it inside the sealing tube in the sealed state, deterioration due to oxidation of the substrate and the thermal radiation layer is prevented.

JP-A-2015-138638

In the conventional thermal radiation light source, the substrate and the thermal radiation layer are arranged inside the sealing tube in a sealed state, so that the entire structure is complicated and expensive. Therefore, the substrate and the thermal radiation layer are placed in the atmosphere. There is a demand for a thermal radiation light source that can be installed in an exposed state.

Further, for the purpose of heating the object to be heated with infrared rays, etc., a large emissivity (emissivity) is set in a setting region set in a wavelength range of 8 μm or less (for example, a setting region of 0.8 μm or more and 4 μm or less). There is a demand for a thermal radiation light source having a small emissivity (emissivity) having a wavelength larger than 8 μm (that is, far-infrared light).

The present invention has been made in view of the above circumstances, and an object of the present invention is that the substrate and the thermal radiation layer can be installed in a state of being exposed to the atmosphere, and the present invention is set in a wavelength range of 8 μm or less. The point is to provide a thermal radiation light source which has a large emissivity (emissivity) in the setting region and can simplify the configuration.

The heat radiant light source of the present invention is obtained by laminating a heat radiant layer and a substrate for heating the heat radiant layer, and the characteristic configuration thereof is that the surface of the substrate facing the heat radiant layer is a mirror surface. Formed of cantal alloy, which is
The thermal radiation layer is formed of a radiation control unit including a MIM laminated portion for locating a transparent oxide layer for resonance formed of a transparent oxide between the substrate and the platinum layer, and the transparent oxide. The radiation control unit and the radiation transparent oxide layer are laminated in a form in which the radiation transparent oxide layer is located closer to the substrate in this order.
The thickness of the transparent oxide layer for resonance is such that the set region set in the wavelength region of 8 μm or less is the resonance wavelength region.

That is, the radiation control unit and the radiation transparent oxide layer are laminated in such a manner that the radiation control unit is located closer to the substrate in the order of the radiation control unit including the MIM laminated unit and the radiation transparent oxide layer. Therefore, when the substrate formed of the cantal alloy is energized to bring the substrate to a high temperature state and the thermal radiation layer is heated to a high temperature state by the substrate, radiation control including a MIM laminated portion is provided. The unit emits radiant light, and the radiant light is radiated from the transparent oxide layer for radiation.

Further, since the transparent oxide layer for radiation, which has a lower refractive index than platinum and a higher refractive index than air, is located adjacent to the platinum layer in the radiation control unit, the reflectance of the platinum layer is reduced and radiation control is performed. The radiated light radiated from the part can be satisfactorily emitted to the outside.

The MIM laminated portion included in the radiation control unit positions the transparent oxide layer for resonance between the substrate formed of the cantal alloy and the platinum layer, and the thickness of the transparent oxide layer for resonance is thick. However, since the thickness is such that the set region set in the wavelength range of 8 μm or less is the resonance wavelength range, the resonance of the radiant light radiated from the substrate in a high temperature state or the platinum layer heated in a high temperature state. It has a large radiation rate (radiation rate) at wavelengths in the wavelength range and a small radiation rate (radiation rate) at wavelengths outside the resonance wavelength range, and as a result, radiant light at the amplified resonance wavelength range. Will be released to the outside from the transparent oxide layer for radiation.

To add an explanation, MIM means a metal integral metal, and the MIM laminated portion emits radiant light having a wavelength in the resonance wavelength range among the radiated light emitted by the substrate and the platinum layer, and the substrate and platinum. By repeatedly reflecting between the layers (inside the transparent oxide layer for resonance), the radiated light of the wavelength in the resonance wavelength range is amplified, and the radiated light of the amplified resonance wavelength range is emitted. It will be released to the outside from the transparent oxide layer.

That is, the radiant light having a wavelength in the resonance wavelength range is amplified while being repeatedly reflected between the substrate and the platinum layer, and a part of the radiant light having a wavelength in the resonance wavelength range is on the side where the transparent oxide layer for radiation exists. It is transmitted and emitted to the outside from the transparent oxide layer for radiation, and as a result, radiated light having a wavelength in the amplified resonance wavelength range is emitted to the outside from the transparent oxide layer for radiation. become.

On the other hand, the radiant light having a wavelength outside the resonance wavelength range of the radiant light radiated from the substrate and the platinum layer is outside from the transparent oxide layer for radiation in a state where it is rarely amplified by the resonance action. Will be released to.
As a result, the radiated light emitted to the outside from the transparent oxide layer for radiation has a large emissivity (emissivity) at the wavelength in the resonance wavelength range and a small emissivity (emissivity) at the wavelength outside the resonance wavelength range. ).

In this way, the thermal radiation layer amplifies the radiant light of the wavelength in the resonance wavelength range and emits it to the outside from the transparent oxide layer for radiation. In addition, even if it is installed in the air, the radiation control unit In addition, the deterioration of the substrate due to oxidation is suppressed, so that the optical characteristics can be maintained for a long time.

That is, the platinum layer of the MIM laminated portion is formed of platinum, and platinum is installed in the air because the standard Gibbs oxide energy is positively large in all temperature ranges and does not oxidize in the air. However, it does not deteriorate due to oxidation.
Further, even when the transparent oxide layer for radiation and the transparent oxide layer for resonance are formed of a material in which the substrate is oxidized in order to suppress the permeation of oxygen in the air toward the substrate. Therefore, deterioration of the substrate due to oxidation is suppressed over a long period of time.
Therefore, even if the thermal radiant zone is installed in the air, the optical characteristics can be maintained for a long time.

By the way, platinum forming a platinum layer adjacent to the transparent oxide layer for resonance may flow and aggregate on the transparent oxide layer for resonance when heated to a high temperature, but transparent oxidation for radiation Since the physical layer exerts an action of suppressing the movement of platinum, the aggregation of platinum can be suppressed, and from this point as well, the thermal radiation layer can maintain the optical characteristics for a long time.

Further, since the radiation control unit provided in the thermal radiation layer includes a MIM laminated unit in which the transparent oxide layer for resonance formed of the transparent oxide is located between the substrate and the platinum layer, in other words. Since the substrate formed of the Kanthal alloy is also used as a member constituting the MIM laminated portion, the configuration can be simplified.

To add an explanation, it is conceivable that a pair of platinum layers are provided as platinum layers and a transparent oxide layer for resonance is arranged between the platinum layers to form a MIM laminated portion. In some cases, the configuration becomes complicated due to the increase in the number of platinum layers to be laminated.
On the other hand, by using the substrate formed of the Kanthal alloy as the member constituting the MIM laminated portion, the configuration can be simplified.

That is, the inventor of the present invention has found that a substrate formed of a Kanthal alloy emits radiant light and appropriately reflects the radiant light in order to form a MIM laminated portion. By also using the substrate formed in (1) as a member constituting the MIM laminated portion, the configuration has been simplified.

In short, according to the characteristic configuration of the thermal radiation light source of the present invention, the substrate and the thermal radiation layer can be installed in a state of being exposed to the atmosphere, and a large emissivity is obtained in a setting region set in a wavelength range of 8 μm or less. It has (emissivity), and in addition, the configuration can be simplified.

A further characteristic configuration of the thermal radiation light source of the present invention is that the set region is a wavelength region of 0.8 μm or more and 4 μm or less.

That is, the MIM laminated portion included in the radiation control unit positions the transparent oxide layer for resonance between the substrate formed of the cantal alloy and the platinum layer, and the thickness of the transparent oxide layer for resonance. However, since the thickness is such that the set region of 0.8 μm or more and 4 μm or less is the resonance wavelength region, the wavelength of 0.8 μm or more and 4 μm or less of the radiated light of the substrate and the platinum layer of the MIM laminated portion resonates. Is amplified by.

On the other hand, of the radiant light emitted from the substrate or the platinum layer, the radiant light having a wavelength of less than 0.8 μm or a wavelength larger than 4 μm is transparent for radiation in a state where it is less likely to be amplified by the resonance action. It will be released to the outside from the oxide layer.

Therefore, the radiation control unit has a large radiation rate (radiation) in a narrow band wavelength including near-infrared light having a wavelength of 0.8 μm or more and less than 2.5 μm and mid-infrared light having a wavelength of 2.5 μm or more and 4 μm or less. Medium-infrared light with wavelengths less than 0.8 μm (ie, visible light), wavelengths greater than 4 μm (ie, wavelengths greater than 4 μm and less than 8 μm, and wavelengths greater than 8 μm). Far-infrared light) has a small radiation rate (radiation rate), and as a result, amplified radiant light with a wavelength of 0.8 μm or more and 4 μm or less is emitted to the outside from the transparent oxide layer for radiation. become.

By the way, light having a wavelength larger than 4 μm is absorbed by the quartz glass, but light having a wavelength of 4 μm or less is transmitted through the quartz glass, and therefore resonates in the wavelength range of 0.8 μm or more and 4 μm or less. The thermal radiation light source in the wavelength range can be satisfactorily used when heating the object to be heated through the quartz glass.

In short, according to a further characteristic configuration of the thermal radiation light source of the present invention, amplified radiant light having a wavelength of 0.8 μm or more and 4 μm or less can be satisfactorily emitted.

A further characteristic configuration of the thermal radiation light source of the present invention is that the set region is a wavelength region of 2.5 μm or more and 8 μm or less.

That is, the MIM laminated portion included in the radiation control unit positions the transparent oxide layer for resonance between the substrate formed of the cantal alloy and the platinum layer, and the thickness of the transparent oxide layer for resonance. However, since the thickness is such that the set region of 2.5 μm or more and 8 μm or less is the resonance wavelength region, the wavelength of 8 μm or less at 2.5 μm or more of the radiated light emitted by the substrate and the platinum layer of the MIM laminated portion is It is amplified by resonance.

On the other hand, of the radiant light emitted from the substrate or the platinum layer, the radiant light having a wavelength of less than 2.5 μm or a wavelength larger than 8 μm is transparent for radiation in a state where it is less likely to be amplified by the resonance action. It will be released to the outside from the oxide layer.

Therefore, the radiation control unit has a large radiation rate (radiation rate) with respect to mid-infrared light having a wavelength of 2.5 μm or more and 8 μm or less, and is more than near-infrared light of less than 2.5 μm or 8 μm. Also has a small radiation rate (radiation rate) in far-infrared light with a large wavelength, and as a result, the radiated light of mid-infrared light with an amplified wavelength of 2.5 μm or more and 8 μm or less is transparently oxidized for radiation. It will be released from the material layer to the outside.

In short, according to a further characteristic configuration of the thermal radiation light source of the present invention, amplified radiant light of mid-infrared light having a wavelength of 2.5 μm or more and 8 μm or less can be satisfactorily emitted.

A further characteristic configuration of the thermal radiation light source of the present invention is between the platinum layer and the resonance transparent oxide layer in the MIM laminated portion, and between the radiation transparent oxide layer and the platinum layer. The point is that the adhesion layer for platinum is laminated in each case.

That is, since the platinum adhesion layer is provided between the platinum layer and the resonance transparent oxide layer in the MIM laminated portion and between the radiation transparent oxide layer and the platinum layer, the radiation control unit is provided. When the substrate is heated to a high temperature, the platinum layer in the MIM laminated portion can be prevented from flowing and agglomerating, and the platinum layer and the transparent oxide layer for resonance are peeled off due to the difference in the coefficient of thermal expansion. In addition, it is possible to prevent the transparent oxide layer for radiation and the platinum layer from peeling off.

That is, since the adhesion between platinum and the transparent oxide is low, when the radiation control unit is heated to a high temperature state on the substrate, it becomes a platinum layer adjacent to the transparent oxide layer for resonance or a transparent oxide layer for radiation. Adjacent platinum layers may flow and aggregate, but by stacking the platinum adhesion layers, the adhesion of the platinum layer adjacent to the resonance transparent oxide layer to the resonance transparent oxide layer and radiation By enhancing the adhesion of the platinum layer adjacent to the transparent oxide layer for radiation to the transparent oxide layer for radiation, the platinum layer in the MIM laminated part flows when the radiation control unit is heated to a high temperature state on the substrate. It is possible to suppress the agglomeration, and also to prevent the platinum layer and the transparent oxide layer for resonance from being peeled off, and the transparent oxide layer for radiation and the platinum layer from being peeled off.

In short, according to the further characteristic configuration of the thermal radiation light source of the present invention, when the radiation control unit is heated to a high temperature state on the substrate, the platinum layer in the MIM laminated unit can be suppressed from flowing and aggregating.

A further characteristic configuration of the thermal radiation light source of the present invention is that the adhesion layer for platinum is formed of titanium.

That is, titanium has adhesion of the platinum layer adjacent to the transparent oxide layer for resonance to the transparent oxide layer for resonance and adhesion of the platinum layer adjacent to the transparent oxide layer for radiation to the transparent oxide layer for radiation. In addition, since the melting point is as high as 1668 ° C., when the radiation control unit is heated to a high temperature state on the substrate, the platinum layer in the MIM laminated unit flows and aggregates. Can be appropriately suppressed.

Incidentally, the titanium forming the adhesion layer for platinum may be gradually oxidized and changed to titanium oxide by using the thermal radiation light source in the atmosphere. In other words, when a thermal radiation source is used in the atmosphere, it can be considered that the platinum adhesion layer is formed of titanium oxide.
However, not all of the titanium that forms the adhesion layer for platinum changes to titanium oxide, and the titanium that adheres to the platinum layer is in the state of titanium that adheres to the platinum layer without being oxidized (metal state). ) Will be continued.

The adhesion layer for platinum formed of titanium is formed in a thin film state so as to have light transmission, and the titanium formed in such a thin film state is changed to titanium oxide. However, since titanium oxide has transparency, even if titanium is changed to titanium oxide, the performance of the thermal radiation layer is not adversely affected.

In short, according to a further characteristic configuration of the thermal radiation light source of the present invention, when the radiation control unit is heated to a high temperature state on the substrate, the platinum layer in the MIM laminated unit is appropriately suppressed from flowing and aggregating. can.

A further characteristic configuration of the thermal radiant light source of the present invention is that the transparent oxide is aluminum oxide.

That is, since aluminum oxide has a small oxygen diffusion coefficient, oxygen in the atmosphere permeates by using aluminum oxide as the transparent oxide forming the transparent oxide layer for radiation and the transparent oxide layer for resonance. Even when the substrate is made of a material to be oxidized, it is possible to appropriately prevent the surface of the substrate on the side where the radiation control unit is laminated from being deteriorated by oxidation.

In short, according to the further characteristic configuration of the thermal radiation light source of the present invention, it is possible to appropriately prevent the surface of the substrate on the side where the radiation control unit is laminated from being deteriorated by oxidation.

It is a figure which shows the basic structure of a thermal radiant light source. It is a table which shows the structural example in the basic structure of a thermal radiant light source. It is a graph which shows the relationship between the structural example of a thermal radiation light source, and the radiation spectrum. It is a figure which shows another form in the basic structure of a thermal radiant light source. It is a graph which shows the relationship between another form of a basic structure and a radiation spectrum. It is a figure which shows the specific structure of the thermal radiant light source. It is a graph which shows the relationship between the thickness of the adhesion layer for platinum, and the radiation spectrum. It is a figure which shows the change of the adhesion layer for platinum. It is a graph which shows the relationship between the change of the transparent oxide layer for resonance and the radiation spectrum. It is a table which shows the example of another structure in the basic structure of a thermal radiant light source. It is a graph which shows the relationship between another structure example of a thermal radiant light source, and radiant intensity. It is a graph which shows the relationship between the thickness of the transparent oxide layer for radiation, and the radiation intensity. It is a table which shows further another structural example in the basic structure of a thermal radiant light source. It is a graph which shows the relationship between the radiant intensity and another structural example of a thermal radiant light source.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Basic configuration of thermal radiation light source]
FIG. 1 shows the basic configuration of the heat radiation light source Q, and the heat radiation light source Q is configured in a form in which the heat radiation layer N and the substrate K for heating the heat radiation layer N are laminated.
The thermal radiation layer N is located closer to the substrate K in the order of the radiation control unit Na and the radiation transparent oxide layer Nb formed of the transparent oxide, and the radiation control unit Na and the radiation transparent oxidation It is configured in a state where the material layers Nb are laminated.

The substrate K is made of a Kanthal alloy (FeCrAl alloy). The Kanthal alloy contains iron (Fe) as a main component, chromium (Cr) of 20% to 30%, and aluminum (Al) of 4% to 7.5%.
As the Kanthal alloy (FeCrAl alloy), Kanthal manufactured by Kanthal Co., Ltd. is desirable, and Kanthal APM is particularly desirable.
Incidentally, the substrate K formed of the Kanthal alloy (FeCrAl alloy) self-heats when energized to heat the thermal radiant zone N.

The radiation control unit Na is configured to include a MIM laminated unit M in which the transparent oxide layer R for resonance formed of the transparent oxide is located between the substrate K and the platinum layer P. That is, the substrate K formed of the Kanthal alloy (FeCrAl alloy) is also used as a member constituting the MIM laminated portion M in the radiation control unit Na.

The thickness of the transparent oxide layer R for resonance is such that the set region set in the wavelength region of 8 μm or less is set as the resonance wavelength region.
In this basic configuration, the setting region is set to a wavelength range of 0.8 μm or more and 4 μm or less.
That is, the thickness of the transparent oxide layer R for resonance is 4 μm or less in the near infrared region (0.8 μm or more and less than 2.5 μm) and the mid-infrared region (2.5 μm or more and 8 μm or less). The thickness is set to the resonance wavelength range.

In the basic configuration of the thermal radiation light source Q shown in FIG. 1, the radiation control unit Na includes one MIM laminated unit M.
That is, in the basic configuration of the thermal radiation light source Q, the resonance transparent oxide layer R, the platinum layer P, and the radiation transparent oxide layer Nb constituting the MIM laminated portion M are arranged in the order described in the MIM laminated portion M. Are sequentially laminated on the upper part of the substrate K for forming the above.

Then, by heating the heat radiation layer N to a high temperature state (for example, 800 ° C.) on the substrate K, the heat radiation light source Q is configured to emit the radiation light H from the heat radiation layer N.
Specifically, the radiated light H has a large radiation rate (radiation rate) at a narrow band wavelength of 0.8 μm or more and 4 μm or less, and has a wavelength of less than 0.8 μm (that is, visible light) and 4 μm. It emits radiated light H having a small radiation rate (radiation rate) in light having a larger wavelength (that is, mid-infrared light having a wavelength larger than 4 μm and 8 μm or less, far infrared light having a wavelength larger than 8 μm). It is configured as follows.

That is, when the thermal radiation layer N is heated to a high temperature state (for example, 800 ° C.) on the substrate K, the radiation control unit Na emits radiant light, and the emissivity (emissivity) of the radiant light is As shown in FIG. 3, at a wavelength of 4 μm or less, the tendency tends to gradually increase toward a short wavelength, and at a wavelength larger than 4 μm, a low value is maintained.

Since the thickness of the transparent oxide layer R for resonance included in the MIM laminated portion M is such that the wavelength of 0.8 μm or more and 4 μm or less is the resonance wavelength region, the substrate K and platinum of the MIM laminated portion M Of the radiated light of layer P, wavelengths of 0.8 μm or more and 4 μm or less are amplified by resonance action.
Therefore, the radiation control unit Na has a large radiation coefficient at a narrow band wavelength including near-infrared light having a wavelength of 0.8 μm or more and less than 2.5 μm and mid-infrared light having a wavelength of 2.5 μm or more and 4 μm or less. As a result of having the radiation rate), the amplified radiant light H having a wavelength of 0.8 μm or more and a wavelength of 4 μm or less is emitted to the outside from the transparent oxide layer Nb for radiation.

To add an explanation, MIM means a metal integral metal, and the MIM laminated portion M emits radiated light having a wavelength of 0.8 μm or more and 4 μm or less among the radiated light of the substrate K and the platinum layer P. By repeatedly reflecting between the substrate K and the platinum layer P, the radiant light having a wavelength of 4 μm or less at 0.8 μm or more is amplified, and the radiant light having a wavelength of 4 μm or less at 0.8 μm or more is amplified. , It will be released to the outside from the transparent oxide layer Nb for radiation.

That is, radiant light having a wavelength of 0.8 μm or more and 4 μm or less is amplified while being repeatedly reflected between the substrate K and the platinum layer P, and a part of the radiant light having a wavelength of 0.8 μm or more and 4 μm or less is generated. It penetrates to the existing side of the transparent oxide layer Nb for radiation and is emitted to the outside from the transparent oxide layer Nb for radiation. As a result, the amplified 0.8 μm or more and 4 μm or less wavelength. The radiated light is emitted to the outside from the transparent oxide layer Nb for radiation.

On the other hand, of the radiant light emitted by the substrate K and the platinum layer P, the radiant light having a wavelength less than 0.8 μm and the radiant light having a wavelength larger than 4 μm are less likely to be amplified by the resonance action. , It will be released to the outside from the transparent oxide layer Nb for radiation.
As a result, the radiant light H (radiant light emitted from the transparent oxide layer Nb for radiation to the outside) emitted from the thermal radiation light source Q has a narrow wavelength of 0.8 μm or more and 4 μm or less (that is, the wavelength is high). It has a large radiation rate (radiation rate) in near-infrared light of 0.8 μm or more and less than 2.5 μm and in a narrow band wavelength including mid-infrared light of 2.5 μm or more and 4 μm or less. Small radiation rate (radiation) at wavelengths less than 8 μm (ie, visible light) and wavelengths greater than 4 μm (ie, mid-infrared light with wavelengths greater than 4 μm and less than 8 μm, far infrared light with wavelengths greater than 8 μm) Rate).

Further, since the transparent oxide layer Nb for radiation has a higher refractive index than platinum and a smaller refractive index than air, the reflectance of the platinum layer P located adjacent to the transparent oxide layer Nb for radiation is high. This will reduce the amount of radiation, and the radiation emitted from the radiation control unit Na can be satisfactorily emitted to the outside.

Incidentally, in the thermal radiation light source Q having the basic configuration of the present invention, "the maximum value of the emissivity between 0.8 μm and 4 μm (near infrared to mid-infrared region) is 90% or more, while the maximum value is 4 μm or more. It is desirable to have a configuration (hereinafter referred to as an appropriate configuration) that "the radiation peaks in the infrared region and the far infrared region are small and have no emissivity peak".

[Explanation of structural example of basic configuration]
Next, a structural example in the basic configuration of the thermal radiation light source Q will be described. In the structural example described below, the transparent oxide forming the transparent oxide layer Nb for radiation and the transparent oxide layer R for resonance is alumina (aluminum oxide, Al ₂ O ₃ ).

As shown in the table of FIG. 2, the structural examples described below are four examples of structures 1 to 4. In the table of FIG. 2, the substrate K is referred to as layer No1, the resonance transparent oxide layer R is referred to as layer No2, the platinum layer P is referred to as layer No3, and the radiation transparent oxide layer Nb is referred to as layer No4.

As shown in FIG. 3, the thermal radiation light source Q of structures 1 to 4 includes near-infrared light having a wavelength of 0.8 μm or more and less than 2.5 μm and mid-infrared light having a wavelength of 2.5 μm or more and less than 4 μm. Has a large radiation rate (radiation rate) in narrow band wavelengths including, and at wavelengths larger than 4 μm (that is, mid-infrared light with wavelengths larger than 4 μm and 8 μm or less, far infrared light larger than 8 μm). It emits radiated light H having a small radiating rate (radiation rate).

When the thickness (thickness) of the transparent oxide layer R for resonance of layer No. 2 is thin, the resonance frequency is shortened, so that the peak position of the radiance is on the short wavelength side, and the transparent for resonance of layer No. 2 is transparent. When the thickness (thickness) of the oxide layer R is large, the resonance frequency becomes longer, so that the peak of the radiance tends to move to a longer wavelength.

Further, when the film thickness (thickness) of the platinum layer P of layer No. 3 is thick, the peak of the radiance spectrum is narrowed, and when the film thickness (thickness) of the platinum layer P of layer No. 3 is thin, radiation is emitted. The peak of the rate spectrum tends to widen.
Further, as the film thickness (thickness) of the transparent oxide layer Nb for radiation of layer No. 4 becomes thicker, the emissivity spectrum tends to move to the longer wavelength side.

When the thermal radiation light source Q has the above-mentioned proper configuration, the preferable range of the film thickness (thickness) of the platinum layer P is, for example, 1.5 nm or more and 18 nm or less.
In FIG. 3, the “mirror surface cantal” means a cantal APM whose surface facing the thermal radiation layer N is a mirror surface, and the radiation spectrum of the cantal APM is also shown in FIG.
Structures 1 to 4 exhibit a higher emissivity than "mirror cantal" in radiant light having a wavelength of 0.8 μm or more and 4 μm or less.

When the thermal radiation light source Q has the above-mentioned appropriate configuration, the preferable range of the thickness (thickness) of the transparent oxide layer R for resonance having a wavelength range of 0.8 μm or more and 4 μm or less as a resonance wavelength range is transparent. When the oxide is alumina (Al ₂ O ₃ ), it is 60 nm or more and 1050 nm or less.
When the thermal radiation light source Q has the above-mentioned proper configuration, the preferable range of the film thickness (thickness) of the transparent oxide layer Nb for radiation of layer No. 4 is, for example, 50 nm or more and 500 nm or less.

[Another form of basic configuration]
In the above-mentioned basic configuration, the case where the radiation control unit Na includes one MIM laminated unit M is illustrated, but the radiation control unit Na may include a plurality of MIM laminated units M.
In addition, when a plurality of MIM laminated portions M are provided, two or more platinum layers P arranged along the stacking direction of the thermal radiation layer N and the substrate K are provided, and between adjacent ones in the platinum layer P. , It means a form in which the transparent oxide layer R for resonance is positioned.

FIG. 4 illustrates a case where the radiation control unit Na includes two MIM laminated units M, and hereinafter, the illustrated thermal radiation light source Q is referred to as a structure 5.
The structure 5 is configured such that the transparent oxide layer R for resonance, the platinum layer P, the transparent oxide layer R for resonance, the platinum layer P, and the transparent oxide layer Nb for radiation are laminated in this order on the upper part of the substrate K. There is.
In the structure 5, the transparent oxide forming the transparent oxide layer Nb for radiation and the transparent oxide layer R for resonance is alumina (Al ₂ O ₃ ).

Then, one MIM laminated portion M is composed of the substrate K, the transparent oxide layer R for resonance, and the platinum layer P, and one MIM laminated portion M is formed from the platinum layer P, the transparent oxide layer R for resonance, and the platinum layer P. As a result, the radiation control unit Na includes two MIM laminated units M.

In the structure 5, the thickness of the transparent oxide layer R for resonance adjacent to the substrate K is 65 nm, the thickness of the platinum layer P located closer to the substrate K is 8 nm, and the thickness of the transparent oxide layer P for resonance is transparent between the two platinum layers P. FIG. 5 shows a radiation spectrum when the thickness of the oxide layer R is 145 nm, the thickness of the platinum layer P2 located on the side away from the substrate K is 5 nm, and the thickness of the transparent oxide layer Nb for radiation is 72 nm. show.
Note that FIG. 5 also shows the radiation spectrum of the above-mentioned structure 1.

In the structure 5, since the resonance wavelengths (frequency) of the two MIM laminated portions M are different, as shown in FIG. 5, resonance can be performed even with a wavelength of visible light having a wavelength of 0.4 μm or more and less than 0.8 μm. become.
Therefore, as the amplified radiant light H having a wavelength of 4 μm or less, in addition to near-infrared light having a wavelength of 0.8 μm or more and less than 2.5 μm and mid-infrared light having a wavelength of 2.5 μm or more and 4 μm or less, Visible light having a wavelength of 0.4 μm or more and less than 0.8 μm and radiated light H including ultraviolet light having a wavelength of less than 0.4 can be obtained.

[Types of transparent oxides]
In the above basic configuration and another form of the basic configuration of the thermal radiation light source Q, the case where the transparent oxide forming the radiation transparent oxide layer Nb and the resonance transparent oxide layer R is alumina (Al ₂ O _{3) is used.} As an example, examples of the transparent oxide include tantalum pentoxide (Ta ₂ O ₅ ), silicon dioxide (SiO ₂ ), niobium pentoxide (Nb ₂ O ₅ ), magnesium oxide (MgO), titanium oxide (TIO ₂ ), and the like. Hafnium oxide (HfO ₂ ) or the like can be used.
Since alumina (Al ₂ O ₃ ) and titanium oxide (TiO ₂ ) have a small oxygen diffusivity, they are particularly suitable as transparent oxides for forming the transparent oxide layer Nb for radiation and the transparent oxide layer R for resonance. preferable.

[Specific configuration of thermal radiation light source]
As shown in FIG. 6, the specific configuration of the thermal radiation light source Q is between the transparent oxide layer R for resonance and the platinum layer P in the MIM laminated portion M, and between the transparent oxide layer Nb for radiation and the radiation control unit Na. In this configuration, the platinum adhesion layer S is laminated on each of the platinum layer P adjacent to the radiation transparent oxide layer Nb.

That is, the platinum adhesion layer S is provided between the resonance transparent oxide layer R and the platinum layer P in the MIM laminated portion M, and between the radiation transparent oxide layer Nb and the platinum layer P. Therefore, when the radiation control unit Na is heated to a high temperature on the substrate K, the platinum layer P in the MIM laminated unit M is suppressed from flowing and agglomerating, and the platinum layer P and the transparent oxide layer R for resonance are suppressed. It is suppressed that the platinum layer P and the transparent oxide layer Nb for radiation are separated from each other.

That is, since the adhesion between platinum and the transparent oxide is low, when the radiation control unit Na is heated to a high temperature state on the substrate K, the platinum layer P adjacent to the transparent oxide layer R for resonance and the transparent for radiation The platinum layer P adjacent to the oxide layer Nb may flow and aggregate, but the platinum layer P adjacent to the transparent oxide layer R for resonance is transparent for resonance due to the lamination of the adhesion layer S for platinum. By enhancing the adhesion to the oxide layer R and the adhesion of the platinum layer P adjacent to the radiation transparent oxide layer Nb to the radiation transparent oxide layer Nb, the radiation control unit Na is in a high temperature state on the substrate K. When heated to, the platinum layer P in the MIM laminated portion M is prevented from flowing and aggregating.

As a material for forming the adhesion layer S for platinum, titanium (Ti) and chromium (Cr) are excellent from the viewpoint of melting point and adhesion. In particular, titanium (Ti) is desirable. Hereinafter, it is assumed that the adhesion layer S for platinum is formed of titanium (Ti).

That is, titanium (Ti) is used for adhesion of the platinum layer P adjacent to the resonance transparent oxide layer R to the resonance transparent oxide layer R and for radiation of the platinum layer P adjacent to the radiation transparent oxide layer Nb. Since the adhesion to the transparent oxide layer Nb can be satisfactorily improved and the melting point is as high as 1668 ° C., when the radiation control unit Na is heated to a high temperature state on the substrate K, the MIM laminated unit It is possible to appropriately suppress the flow and aggregation of the platinum layer P in M.

[Thickness of adhesion layer for platinum]
The thickness (film thickness) of the platinum adhesion layer S needs to be set from the two viewpoints of opticality and durability.
That is, if the thickness (film thickness) of the platinum adhesion layer S is too thick, it is not optically good. That is, when the platinum adhesion layer S is in a high temperature state, it emits radiant light having a wavelength larger than 4 μm (that is, far infrared light), so that the thickness (thickness) of the platinum adhesion layer S2 is increased. If it is too thick, the intensity of the radiated light from the platinum adhesion layer S will increase, and the radiated light from the radiation control unit Na will have a small emissivity (emissivity) at a wavelength larger than 4 μm. It has an adverse effect.

FIG. 7 shows a change in emissivity when the thickness of the platinum adhesion layer S is changed when the platinum adhesion layer S is formed of titanium (Ti).
The configuration of the thermal radiation light source Q illustrated in FIG. 7 is such that the thickness of the transparent oxide layer R for resonance adjacent to the substrate K is 120 nm, the thickness of the platinum layer P is 6 nm, and the thickness of the transparent oxide layer Nb for radiation is It shows the change of the emissivity when the thickness of the two adhesion layers S for platinum is changed when the value is 120 nm.

As shown in FIG. 7, as the thickness of the platinum adhesion layer S becomes thicker, infrared light on the wavelength side longer than 4 μm, that is, mid-infrared light having a wavelength larger than 4 μm and 8 μm or less, and larger than 8 μm. Far-infrared light tends to increase.
The thickness (thickness) of the platinum adhesion layer S formed of titanium (Ti) is preferably set to about sub nm (about 1 nm) for the following reasons.

[Oxidation of titanium]
Titanium (Ti) forming the platinum adhesion layer S is likely to be _{gradually oxidized and changed to titanium oxide (TiO 2} ) by using the thermal radiation light source Q in the atmosphere. In other words, when the thermal radiation light source Q is used in the atmosphere, it can be considered that the platinum adhesion layer S is formed of _{titanium oxide (TiO 2).}

However, as shown in FIG. 8, not all of the titanium forming the platinum adhesion layer S is changed to titanium oxide, and the titanium at the portion that adheres to the platinum layer P is not oxidized and is not oxidized. The state of titanium (metal state) in close contact with P will be continued.

That is, not all of the titanium forming the platinum adhesion layer S is changed to titanium oxide, but the titanium at the portion that adheres to the platinum layer P is in a state of titanium that adheres to the platinum layer P without being oxidized. Will continue, and the function as the adhesion layer S for platinum will be continued.

To add an explanation, platinum (Pt) does not react with oxygen because the standard Gibbs energy change is + 200 k / mol / O ₂ (the chemical reaction proceeds in the direction in which the Gibbs energy change becomes negative. A positive energy change means no reaction.) This means that it is difficult to use an oxide as an adhesion layer of platinum (Pt) due to the binding energy. From this, if titanium is changed to titanium oxide by oxidation, there is a concern that it will not work as an adhesion layer of platinum (Pt), but in reality, even if titanium is oxidized, titanium at the interface with platinum (Pt) will not work. Since the bond with platinum is maintained, the function as the adhesion layer S for platinum will be continued.

By the way, the adhesion layer S for platinum formed of titanium is formed in a thin film state so as to have light transmission, and the titanium formed in the thin film state is changed to titanium oxide. However, since titanium oxide has transparency, even if titanium is changed to titanium oxide, the performance of the thermal radiation layer N is not adversely affected.
Considering that the material forming the adhesion layer S for platinum is oxidized, chromium (Cr) turns black when oxidized, so chromium which turns black when oxidized is not suitable as an adhesion layer from the viewpoint of radiation control. On the other hand, _{titanium (Ti), which forms titanium oxide (TiO 2} ) that becomes transparent when oxidized, is excellent from the viewpoint of radiation control.

By the way, if the titanium (Ti) of the platinum adhesion layer S oxidizes over time, even if the platinum adhesion layer S is thick, it will eventually become heat radiation when the thickness (film thickness) of FIG. 8 is thin. It is thought that it will approach. However, when the thickness (film thickness) is large, when the radiation control unit Na is heated to a high temperature state on the substrate K, titanium (Ti) moves around due to heat and appears on the surface of the platinum layer P. It may occur. When such a phenomenon occurs, the thermal radiation control structure of the radiation control unit Na is disrupted, which makes it difficult to control the thermal radiation. In particular, since the platinum in the platinum layer P is thin, the movement of titanium (Ti) has a great influence on the collapse of the thermal radiation control structure.
Therefore, it is desirable that the thickness (film thickness) of the adhesion layer S for platinum is about sub nm (about 1 nm).

[About changes over time in thermal radiant light sources]
FIG. 9 shows a thermal radiation spectrum when the actually produced thermal radiation light source Q is heated to 800 ° C. in the atmosphere and used for 24 hours, and the thermal radiation spectrum immediately after film formation is also shown.
In FIG. 9, the thickness of the transparent oxide layer for resonance is 150 nm, the thickness of the platinum layer P is 6 nm, the thickness of the transparent oxide layer Nb for radiation is 150 nm, and the thickness of the adhesion layer S for platinum is set. It exemplifies the thermal radiation spectrum of the thermal radiation light source Q when it is set to 0.5 nm.

The thermal radiation spectrum immediately after film formation and the thermal radiation spectrum after heating for 24 hours are different, because _{the crystallinity of alumina (Al 2} O ₃ ) and platinum (Pt) is increased by heating. it is conceivable that.

The theoretical value (calculated value) thermal radiation spectrum is calculated using the optical constant _{of highly crystalline alumina (Al 2} O _3).
The heat radiation spectrum immediately after film formation deviates from the theoretical value (calculated value) heat radiation spectrum, but the heat radiation spectrum after heating is extremely close to the theoretical value (calculated value) heat radiation spectrum. Therefore, it is assumed that _{the optical constants of alumina (Al 2} O ₃ ) and platinum (Pt) approach the theoretical values _{because the crystallinity of alumina (Al 2} O ₃ ) and platinum (Pt) is increased by heating. Conceivable.

As shown in the above results, the thermal radiant light source Q of the present invention is a thermal radiant light source that can be used by heating it to about 800 ° C. in the atmosphere.
The melting point of the constituent material of the thermal radiation light source Q of the present invention is 1768 ° C. for platinum (Pt) _{, 2072 ° C. for alumina (Al 2} O ₃ ), 1668 ° C. for titanium (Ti), and titanium oxide (TIO). ₂ ) is 1843 ° C., the substrate K (Kanthal alloy) is 1300 ° C., and the thermal radiation light source Q of the present invention can be used at about 800 ° C. in the atmosphere from this point as well.

[About another configuration of thermal radiation light source]
In the basic configuration of the thermal radiation light source Q described above, a configuration in which the setting region for the resonance wavelength region is set to a wavelength region of 0.8 μm or more and 4 μm or less is illustrated.
Next, as another configuration of the basic configuration of the thermal radiation light source Q, a configuration in which the setting region as the resonance wavelength region is set to a wavelength region of 2.5 μm or more and 8 μm or less will be described.

The different configuration of the basic configuration of the thermal radiant light source Q is basically the same as the basic configuration of the thermal radiant light source Q described above, but the thickness of the transparent oxide layer R for resonance is 2.5 μm or more in wavelength. It differs from the above-mentioned thermal radiation light source Q in that the thickness is set so that the mid-infrared light region of 8 μm or less is set as the resonance wavelength region.

Then, by heating the heat radiation layer N to a high temperature state (for example, 300 ° C.) on the substrate K, the heat radiation light source Q is configured to emit the radiation light H from the heat radiation layer N.
Specifically, the radiated light H has a large radiation coefficient in the mid-infrared light region of 2.5 μm or more and 8 μm or less, and has a wavelength of less than 2.5 μm (that is, a wavelength of near-infrared light) or 8 μm. Is also configured to emit radiated light H having a small radiation coefficient at a large wavelength (that is, the wavelength of far-infrared light).

That is, when the thermal radiation layer N is heated to a high temperature state (for example, 300 ° C.) on the substrate K, the substrate K and the platinum layer P in the MIM laminated portion M included in the radiation control unit Na emit radiant light. become.
Then, since the thickness of the transparent oxide layer R for resonance included in the MIM laminated portion M is set to a thickness in which the mid-infrared light region of 2.5 μm or more and 8 μm or less is the resonance wavelength region, the MIM laminated portion Of the radiated light of the substrate K of M and the platinum layer P, wavelengths of 2.5 μm or more and 8 μm or less (that is, wavelengths in the mid-infrared light region) are amplified by resonance action.

Therefore, the radiation control unit Na has a large emissivity (emissivity) at a wavelength in the region of 2.5 μm or more and 8 μm or less (that is, a wavelength in the mid-infrared light region), and has a wavelength larger than 8 μm (that is, that is). It has a small emissivity (emissivity) at wavelengths of far infrared light) and wavelengths less than 2.5 μm (that is, wavelengths of near infrared light).
As a result, the radiant light H whose wavelength is amplified at 2.5 μm or more and 8 μm or less is emitted to the outside from the transparent oxide layer Nb for radiation.

[Explanation of another structural example of a thermal radiant light source]
Next, a structural example in another configuration of the basic configuration of the thermal radiant light source Q, that is, another structural example in the basic configuration of the thermal radiant light source Q will be described. In another structural example described below, the transparent oxide forming the transparent oxide layer Nb for radiation and the transparent oxide layer R for resonance is alumina (aluminum oxide, Al ₂ O ₃ ).

As shown in the table of FIG. 10, another structural example is four examples of structures 6 to 9. Incidentally, in the table of FIG. 10, the substrate K is referred to as layer No1, the resonance transparent oxide layer R is referred to as layer No2, the platinum layer P is referred to as layer No3, and the radiation transparent oxide layer Nb is referred to as layer No4.
^{The radiation intensity (W / sr / m 2} / nm) when the thermal radiation layer N in the structures 6 to 9 is heated to 300 ° C. is shown in FIG. In addition, FIG. 11 also shows the radiation intensity of a blackbody at 300 ° C.

The thermal emissivity light source Q of the structures 7 and 8 has a layer No. 2 having a thickness of 1200 nm and 1500 nm, and as shown in FIG. 11, has a wavelength in a region of 2.5 μm or more and 8 μm or less (that is, for mid-infrared light). Has a large emissivity (emissivity), and is small at wavelengths greater than 8 μm (ie, wavelengths of far-infrared light) and less than 2.5 μm (ie, wavelengths of near-infrared light). It tends to have emissivity (emissivity).

The thermal radiant light source Q of the structures 6 and 9 has a layer No. 2 having a thickness of 1000 nm, and as shown in FIG. 11, the peak wavelength that resonates is shorter than that of the thermal radiant light source Q of the structures 7 and 8. However, it has a large emissivity (emissivity) at wavelengths in the region of 2.5 μm or more and 8 μm or less (that is, the wavelength of mid-infrared light), and has a wavelength larger than 8 μm (that is, far-infrared light). It tends to have a small emissivity (emissivity) at wavelengths) and wavelengths less than 42.5 μm (ie, wavelengths of near-infrared light).

[Consideration of transparent oxide layer for radiation]
The transparent oxide layer Nb for radiation exists for antireflection and improvement of durability, which reduces the reflectance of the platinum layer P at the resonance wavelength. Basically, antireflection can be realized with a thickness of about a value obtained by the product of 0.5 and the resonance wavelength / 4. For example, in the case of resonance in the wavelength range of 2500 nm to 7000 nm, a thickness of about 300 nm to 800 nm is desired.
In the structure 9 described above, the emissivity spectrum when the thickness of the layer 4 (transparent oxide layer Nb for radiation) is changed stepwise from 0 nm to 1500 nm is shown in FIG.

When the thickness of the layer 4 (transparent oxide layer Nb for radiation) is 0 nm, it can be seen that the radiation intensity at the peak wavelength does not reach the blackbody radiation spectrum because the radiation rate near the radiation peak near 4 μm is small.
When the thickness of the layer 4 (transparent oxide layer Nb for radiation) is formed to a thickness of 500 nm that can prevent reflection, the radiation intensity at the peak wavelength substantially matches the blackbody radiation spectrum (300 ° C.).

When the thickness of the layer 4 (transparent oxide layer Nb for radiation) is further increased, the radiation intensity at the peak wavelength becomes smaller because the film thickness condition as the antireflection film is deviated. Then, the thermal radiation derived from alumina (aluminum oxide, Al ₂ O ₃ ) becomes large on the long wavelength side.
That is, the thicker the layer 4 (transparent oxide layer Nb for radiation), the larger the thermal radiation of the long wave derived from the layer 4 (transparent oxide layer Nb for radiation).

Therefore, the upper limit of the thickness of the layer 4 (transparent oxide layer Nb for radiation) is about 800 nm.
Further, the lower limit of the thickness of the layer 4 (transparent oxide layer Nb for radiation) is 100 nm or more in consideration of the durability described later.
That is, since the transparent oxide layer Nb for radiation exists for antireflection and improvement of durability, the preferable range of the thickness thereof is, for example, 100 nm or more and 800 nm or less, and particularly 300 nm or more. 800 nm or less is more preferable.

[Explanation of another structural example of the thermal radiant light source]
Next, the structure 10 and the structure 11 will be described as a further example of another structure in another configuration of the thermal radiation light source Q. In another structural example described below, the transparent oxide forming the transparent oxide layer Nb for radiation and the transparent oxide layer R for resonance is alumina (aluminum oxide, Al ₂ O ₃ ).

As another structural example, as shown in the table of FIG. 13, the substrate K is layer No1, the resonance transparent oxide layer R is layer No2, the platinum layer P is layer No3, and the radiation transparent oxide layer Nb is layer No4. It is described as.
Then, FIG. 14 shows ^{the radiation intensity (W / sr / m 2} / nm) when the thermal radiation layer N in the structure 10 and the structure 11 as another structural example is heated to 300 ° C. In addition, FIG. 14 also shows the radiation intensity of a blackbody at 300 ° C.

In the thermal emissivity light source Q of the structure 10 and the structure 11, the thickness of the layer No. 2 is 1200 nm and 1500 nm, and as shown in FIG. 14, the wavelength in the region of 2.5 μm or more and 8 μm or less (that is, the wavelength of mid-infrared light). Has a large emissivity (emissivity), and is small at wavelengths greater than 8 μm (ie, wavelengths of far-infrared light) and less than 2.5 μm (ie, wavelengths of near-infrared light). It tends to have emissivity (emissivity).

In the structures 6 and 7 of the other structural example described above, the thickness of the platinum layer P is 10 nm, whereas the structure 8 of the structural example described above and the structure 10 of another structural example are further described. In the structure 11, the thickness of the platinum layer P is 5 nm.

When the thickness of the platinum layer P is as thin as 10 nm or less, the reflectance of the platinum layer P becomes low, so that it is considered that the transparent oxide layer Nb for radiation is unnecessary, but from the viewpoint of durability, it is considered that the transparent oxide layer Nb for radiation is unnecessary. A transparent oxide layer Nb for radiation is required.
That is, when the platinum forming the platinum layer P2 is heated to a high temperature, it may flow and aggregate on the resonance transparent oxide layer R, but the radiation transparent oxide layer Nb moves the platinum. Since it exerts an inhibitory effect, it is possible to suppress the aggregation of platinum.
Then, in order to suppress the aggregation of platinum and improve the durability, it is preferable that the thickness of the transparent oxide layer Nb for radiation is 100 nm or more.

[Other configurations of thermal radiation light source]
Even in another configuration of the thermal radiation light source Q, that is, in another configuration that emits radiant light H having a large radiation rate (radiation rate) in mid-infrared light having a wavelength of 2.5 μm or more and 8 μm or less, the value is 0.8 μm or more. Similar to the thermal radiation light source Q having a configuration in which radiant light H having a wavelength of 4 μm or less is emitted, a plurality of MIM laminated portions M can be provided, and a specific configuration including a platinum adhesion layer S is provided. However, since the details are the same as those of the thermal radiation light source Q having a configuration in which the radiant light H having a wavelength of 0.8 μm or more and 4 μm or less is emitted, detailed description thereof will be omitted in the present embodiment.

[Another Embodiment]
Hereinafter, another embodiment will be listed.
(1) In the above embodiment, even if the back surface of the substrate K opposite to the surface on which the thermal radiant zone N is laminated is oxidized, if the thickness of the substrate K is thick, the thermal radiant zone N is adversely affected. The back surface of the substrate K opposite to the surface on which the thermal radiation zone N is laminated was exposed, but the back surface is an antioxidant film that suppresses oxidation. May be laminated.

(2) In the above embodiment, as the setting region for the resonance wavelength region of 8 μm or less, a region of 0.8 μm or more and 4 μm or less and a region of 2.5 μm or more and 8 μm or less are exemplified, but other ranges are used. The region may be set as a setting region to be a resonance wavelength region.

The configuration disclosed in the above embodiment (including another embodiment, the same shall apply hereinafter) can be applied in combination with the configuration disclosed in other embodiments as long as there is no contradiction. The embodiments disclosed in the present specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.

K Substrate N Thermal radiation layer Na Radiation control unit Nb Transparent oxide layer for radiation M MIM laminated part P Platinum layer R Transparent oxide layer for resonance

Claims (6)

A thermal radiant light source in which a thermal radiant layer and a substrate for heating the thermal radiant layer are laminated.
The substrate is formed of a Kanthal alloy whose surface facing the thermal radiant zone is a mirror surface.
The thermal radiation layer is formed of a radiation control unit including a MIM laminated portion for locating a transparent oxide layer for resonance formed of a transparent oxide between the substrate and the platinum layer, and the transparent oxide. The radiation control unit and the radiation transparent oxide layer are laminated in a form in which the radiation transparent oxide layer is located closer to the substrate in this order.
A thermal radiation light source in which the thickness of the transparent oxide layer for resonance is a thickness in which a set region set in a wavelength region of 8 μm or less is set as a resonance wavelength region. The thermal radiation light source according to claim 1, wherein the set region is a wavelength region of 0.8 μm or more and 4 μm or less. The thermal radiation light source according to claim 1, wherein the set region is a wavelength region of 2.5 μm or more and 8 μm or less. A claim in which a platinum adhesion layer is laminated between the platinum layer and the resonance transparent oxide layer in the MIM laminated portion and between the radiation transparent oxide layer and the platinum layer, respectively. Item 3. The thermal radiation light source according to any one of Items 1 to 3. The thermal radiation light source according to claim 4, wherein the adhesion layer for platinum is formed of titanium. The thermal radiant light source according to any one of claims 1 to 5, wherein the transparent oxide is aluminum oxide.

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