JP2000100391A - Optical article and light bulb with infrared reflective coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infrared-reflection coating in which a plurality of high-refractive-index films and low-refractive-index films having an optical film thickness of λ / 4 are alternately laminated, and high transmission without coloring in a visible region. It is difficult to satisfy both the characteristics and the reflection characteristics in the infrared region. When an infrared reflective film is formed on an incandescent lamp, an efficient light bulb cannot be obtained. SOLUTION: A low-refractive-index film, a high-refractive-index film, a first multilayer film having one cycle of a low-refractive-index film, a low-refractive-index film, an intermediate-refractive-index film, a high-refractive-index film, and an intermediate film on a glass bulb surface. Forming a second multilayer film having a refractive index film and a low refractive index film as one cycle, and showing a transmittance of 70% or more of light in all wavelength ranges of visible light of at least 450 to 700 nm; And 950
Provided is an incandescent lamp provided with an infrared-reflective coating that satisfies an optical characteristic of reflecting light of 40% or more, in average, 50% or more of light in all wavelength ranges of infrared light of 〜1450 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical article provided with a light-transmitting infrared-reflective coating, and more particularly to providing an infrared-reflective coating on the surface of a glass bulb of a light bulb to reflect infrared light toward the inside of the light bulb. Thus, the present invention relates to a configuration of a light bulb such as an incandescent light bulb in which power consumption of a light bulb filament is reduced to improve lamp efficiency.

[0002]

2. Description of the Related Art FIG. 8 schematically shows an example of a configuration of a conventional incandescent lamp 90 having an infrared reflective coating of this type, with a part thereof enlarged. A base 92 is provided at the bottom of the translucent glass bulb 91, and a base 9 is provided inside the glass bulb 91.
2, a filament 93 is provided. An infrared reflective coating 94 is provided on the surface of the glass bulb 91. The infrared reflection coating 94 is provided for the purpose of returning the infrared rays generated from the filament 93 to the filament 93, whereby the power consumption of the filament and 93 is suppressed, and the lamp efficiency is improved.

FIG. 9 shows the infrared reflective coating 94 in more detail.
It is something. Optical film on outer surface of glass bulb 91
TiO with thickness n · d of λ / 4₂, Ta₂O₅, ZnS
e, a high refractive index material layer 95 such as ZnS and SiO₂, MgF
Alternately with low refractive index material layers 96 such as 8 layers
Approximately 20 layers are laminated. For example, reflect
The design wavelength λ of infrared light is 1000 nm, and high refractive index material
Refractive index n as the material layer 95 _H= Ta of 2.2₂O₅To λ /
4 (= 250 nm), n as the low refractive index material layer 96_L=
1.46 SiO₂Is the optical wavelength of λ / 4 (= 250 nm).
A low-refractive-index material layer 9 on the surface of the glass bulb 91
6, high refractive index material layer 95 ... so that total 10 layers
In the case of alternate lamination, the spectral transmission as shown in FIG.
It becomes the infrared reflective coating 94 having the rate characteristic.

[0004]

However, in the case of the above-described conventional light bulb with an infrared reflective coating, the reflection characteristic is only at about 1000 nm, which is the wavelength set as the optical film thickness, as shown in FIG. And cannot reflect infrared rays near 1500 nm.

[0005] Therefore, it is conceivable to provide an infrared reflective coating having a design wavelength of 1500 nm when setting the optical film thickness on this infrared reflective coating. FIG. 11 shows the spectral transmission characteristics of the infrared reflective coating thus formed. Specifically, the wavelength λ for setting the film formed in FIG.
000 nm, and the refractive index n _H as the high refractive index material layer 95.
= 2.2 Ta ₂ O ₅ is λ / 4 (= 250 nm), and SiO ₂ with n _L = 1.46 is λ /
A design wavelength λ for setting the optical film thickness is set to 15 on a film having a total thickness of 4 (= 250 nm) alternately laminated in a total of 10 layers.
And a high refractive index material layer 95 of Ta _2.
Infrared reflective coating 94 in which O ₅ is λ / 4 (= 375 nm) and SiO ₂ is similarly laminated as low-refractive index material layer 96 to a thickness of λ / 4 (= 375 nm), for a total of 10 layers, and a total of 20 layers are provided. Is the case.

In this case, infrared rays in the wavelength range around 1500 nm can be reflected, and the infrared ray reflection characteristics are improved as compared with the case of FIG. However, the transmittance in the visible region was reduced, and the transmittance near 500 nm was significantly attenuated. This is because a part of the visible light range was reflected by providing an infrared reflective coating formed using a wavelength of 1500 nm as a design wavelength.

[0007] The radiant energy spectrum of an incandescent lamp generally used widely radiates light having a wide range of wavelengths from about 400 nm to 2800 nm. It has a peak of radiant energy near 1000 nm in the infrared region, and emits light having an intensity of about 30% of the peak intensity at 2400 nm. Therefore, when the incandescent lamp is provided with the infrared reflective coating 94 having the characteristics shown in FIG.
There is a problem that the radiation of a wavelength of 0 nm or more cannot be reflected and the efficiency cannot be improved as expected. In addition, when an infrared reflective film that reflects infrared light having a wavelength of 1400 m or more is provided on the layer by alternately laminating a high refractive index material layer and a low refractive index material layer at λ / 4, as shown in FIG. There is a problem that the transmittance of the region is reduced and coloring occurs.

The present invention solves the above-mentioned problems, and provides an optical article having an infrared reflective film having excellent transmittance in the visible region and excellent reflection characteristics in the infrared region, particularly a high-efficiency bulb. The purpose is to: More specifically, at 400 to 750 nm emitted from an incandescent lamp, 70% or more of the light in the entire wavelength range is transmitted, and 800 to 1 nm.
It is an object of the present invention to provide an incandescent lamp provided with an infrared reflective coating that reflects an average of 50% or more of light in the infrared region of 800 nm.

[0009]

According to the present invention, the refractive index is
Translucent red consisting of multiple multilayers on a substrate surface of about 1.5
An optical article having an external reflection coating formed thereon,
Transparent infrared reflective coating is made of high refractive index material (H) and low refractive index
Multilayer film having a multilayer structure of a refractive index material (L) and a high refractive index
Intermediate between material (H), low refractive index material (L) and intermediate refractive index
Second multilayer film having a multilayer structure composed of a refractive index material (M)
And a light of a high refractive index material (H) layer forming a multilayer film.
Chemical thickness: n_Hd_H= Λ_w/ 4 as H, low refraction
Film thickness of the material (L) layer: n_Ld_L= Λ_w/ 4 to L
And the optical thickness of the intermediate refractive index material (M) layer: n
_Md_M= Λ_w/ 4 as M (where n_H,
n_L, N_MIndicates a high refractive index material layer, a low refractive index material layer,
Refractive index of the refractive index material layer, d_H, D_L,d_MIs a high refractive index material
Layer, low refractive index material layer, intermediate refractive index material layer physical thickness,
λ_wDenotes the design wavelength of the optical film thickness, and λ₁Is the first multilayer film
Design wavelength, λ₂Is the design wavelength of the second multilayer))
With infrared reflective coating that satisfies the following conditions (a) to (d)
An optical article is provided. (A) The first multilayer film is an optical film in order from the substrate surface side.
The first layer having a thickness of (L / 2) and the first layer having an optical thickness of H
Three layers of two layers and a third layer having an optical thickness of (L / 2)
The basic structure is the structure, and the basic structure is repeated x cycles.
A film represented by the following equation. [(L / 2) H (L / 2)]^x, (X is an integer of 2 or more
(B) The second multilayer film is an optical film in order from the substrate surface side.
Thickness (L / a₂) And the optical thickness is (M / b)
₂), And the optical thickness is (H / c)₂)
3 layers, optical thickness (M / b₂4) layer and light
(L / a₂) Is based on the five-layer structure of the fifth layer
The following formula is obtained by repeating the basic configuration for y cycles.
The film that is expressed. [(L / a₂) (M / b₂) (H / c₂) (M /
b₂) (L / a₂)] ^y  Here, y is an integer of 2 or more, 2 <a₂<4, 2.5 <b
₂<4.5, 1 <c₂<2. (C) Design wavelength λ of first multilayer film₁Wave of the second multilayer film
Long λ₂Is 780 ≦ λ₁≤1200 nm, 1200 nm
≤λ₂≤2200 nm. (D) Refractive index n of the intermediate refractive index material (M)_MTo 0.32
(N_H-N_L) + N_L<N_M<0.60 (n_H-N_L)
+ N_LAnd

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an optical article of the present invention will be described in detail based on an embodiment shown in FIGS. In FIG. 1, reference numeral 1 denotes a main part of a light bulb according to the present invention. The light bulb has an infrared reflective coating 3 formed on the surface of a glass bulb 2 and a filament (not shown) provided on the inner surface of the glass bulb. Have been.

In the present invention, the infrared reflective coating 3 is formed by sequentially laminating a first multilayer film 31, a second multilayer film 32, and a third multilayer film 33 from the surface side of the glass bulb 2 serving as a base. The first multilayer film 31 has a cycle of an alternately laminated structure of a low-refractive-index material layer (L), a high-refractive-index material layer (H), and a low-refractive-index material layer (L). I have.
The second multilayer film 32 and the third multilayer film 33 include a low refractive index material layer (L), an intermediate refractive index material layer (M), a high refractive index material layer (H), an intermediate refractive index material layer (M), and a low refractive index. The five-layer structure of the rate material layer (L) is one cycle. In order to form the infrared reflective coating 3 composed of such a multilayer film, the cleaned glass bulb 2 is placed in a vacuum apparatus, and a material such as a metal oxide having a desired refractive index is vapor-deposited, sputtered, CV
It can be obtained by a method such as sequentially forming a film while controlling the film thickness by a method D or the like.

Hereinafter, a description will be given along a specific embodiment. (Embodiment 1) FIG. 2 shows the infrared reflection coating 3 in an enlarged manner. The infrared reflective coating 3 has a first multilayer film 31, a second multilayer film 32, a third multilayer film 32 from the surface side of the glass bulb 2 having a refractive index of 1.52.
The multilayer film 33 is sequentially stacked.

The first multilayer film 31 has a configuration of [(L / 2) H (L / 2)] ⁴ from the glass bulb side.
Here, the L indicates that as described above the low refractive index material layer (L) is formed as an optical film thickness n · d of _{λ 31/4, (L /} 2) is a low refractive index material layer Optical thickness λ
1/2 of _31/4, i.e. _{(λ 31/4) × (} 1 /
Which means be provided to the optical film thickness of 2) = λ _31/8. H indicates a high refractive index material layer (H), and λ
_This indicates that the film was formed with an optical film thickness of 31/4. Also, [(L / 2) H (L / 2)] ⁴ in 4 is []
It represents that the basic configuration in which the three-layer alternately laminated structure described in the above is one cycle was laminated for four cycles. Note that λ ₃₁ is a design wavelength used when designing the reflection characteristics of the first multilayer film 31.
Here, the infrared light of 950 nm was used. When a plurality of cycles are laminated, the upper layer of the previous cycle and the lower layer of the lower refractive index material (L) of the next cycle are repeatedly formed. In this case, the same low refractive index material layer (L / 2) is formed. × 2 optical thickness, ie L
= It may be the one formed by the optical film thickness of λ _31/4.

The second multilayer film 32 is formed from the surface side of the glass bulb 2 [(L / 3.2) (M / 3.2) (H / 1.
6) (M / 3.2) (L / 3.2)] The basic configuration of ^{4 was} adopted. Here, M is at the low-refractive index material layer (L) and the high refractive index material layer (H) of the intermediate-refractive index material layer having a refractive index of the intermediate (M) with lambda _32/4 optical film thickness Indicates that it was formed. Other design conditions are shown in the same manner as in the first multilayer film 31. Therefore, for example, (L / 3.2) means (λ ₃₂ /
4) It means that it was formed as an optical film thickness of × (1 / 3.2) = λ ₃₂ /12.8. Here, λ ₃₂ is a design wavelength used when designing the reflection characteristics of the second multilayer film 32, and here, it is 1280 nm infrared. Also,
Four periods are stacked with the five-layer alternating layered structure described in [] as one period.

The third multilayer film 33 is formed from the surface side of the glass bulb 2 [(L / 3.2) (M / 3.2) (H / 1.
6) (M / 3.2) (L / 3.2)] This is a basic configuration of ⁴ . The low-refractive-index material layer (L), the intermediate-refractive-index material layer (M), the high-refractive-index material layer (H), and the like are described similarly to the first multilayer film 31 and the second multilayer film 32 described above. However, here, the design wavelength λ ₃₃ used in designing the optical film thickness is used.
Was 1600 nm infrared.

Based on the above conditions, the first multilayer film 31 and the second multilayer film 31 are formed on the glass bulb 2 so as to have a predetermined optical film thickness.
The infrared reflective coating 3 was formed by continuously forming the multilayer film 32 and the third multilayer film 33. Specifically, a glass bulb is installed in a vacuum evaporation apparatus (not shown), and the first multilayer films 31, 32, 33
, SiO ₂ having a refractive index of 1.46 was used as a deposition source for the low refractive index material layer (L), and Ta ₂ O ₅ having a refractive index of 2.2 was used as a deposition source for the high refractive index material layer (H). The intermediate-refractive-index material layer (M) is formed by using both SiO ₂ and Ta ₂ O ₅ as a vapor deposition source, and vapor-depositing simultaneously by adjusting respective vapor deposition rates so that the refractive index becomes 1.8. Formed. Further, the thickness of each layer was controlled by irradiating the film surface forming light of a predetermined wavelength with an optical measuring device provided in a vacuum vapor deposition device, and performing vapor deposition while measuring the reflectance. For example, the physical thickness d _H of the high-refractive-index material layer (H) of the first multilayer film 31 is determined by changing the optical thickness n · d to λ.
_Since it is formed as 31/4, (950 nm
/4)÷2.2=about 108 nm. FIG. 3 shows the spectral transmittance curve of the infrared reflective coating 3 formed in this manner, and the spectral transmittance of the glass substrate 2 on which the infrared reflective coating 3 is formed in the atmosphere is obtained by calculation. .

An infrared reflective coating 3 was formed on a glass substrate of the same material as a sample for measurement under the above conditions, and the spectral transmittance and reflectance in air were measured by irradiating measurement light from the glass substrate side. . Visible light region 400nm ~ 7
High transmittance of 80% or more and flat characteristics were exhibited at all wavelengths in the wavelength range of 50 nm, and favorable transmission characteristics without coloring were obtained. 900 to 180 in the infrared region
50 nm on average for light in a wide infrared light range of 0 nm.
% Or more. The measurement result of the transmittance was in good agreement with the calculation result of FIG. 3, and it was [1-reflectance ≒ transmittance], and there was almost no absorption in the infrared reflective film. Also,
A case where the (L / 2) low refractive index material layer (L) in contact with the glass bulb 1 of the first multilayer film 31 was formed was omitted, and the same characteristics were exhibited in that case.

Example 2 First Multilayer of Infrared Reflective Coating 3
The film 31 and the second multilayer film 32 are formed with the same structure as in the first embodiment.
The first multilayer is formed on the valve 2 by omitting the third multilayer.
An infrared reflective coating 3 consisting only of the film and the second multilayer film was obtained.
At this time, the low refractive index material layer (L) has a refractive index of 1.46.
SiO₂Is used as an evaporation source, and a high refractive index material layer (H)
And a refractive index of 2.2₂O₅Was used as an evaporation source. Middle bending
As the index material layer (M), SiO₂And Ta₂O₅Both
The refractive index is 1.8 when one of the materials is used as an evaporation source
I adjusted it. The light of each layer in the first multilayer film 31
Wavelength λ to define the chemical film thickness₃₁Is the same as in Example 1.
950 nm, which is the same as the design wavelength λ of the second multilayer film 32.
₃₂Was 1500 nm. Other conditions were completely the same as in Example 1.
Identical.

FIG. 4 shows the calculation results of the spectral transmittance characteristics of the infrared reflective coating under the above conditions. The infrared reflective film formed on the glass bulb 2 under the above conditions has a thickness of 400 nm or more.
It shows a flat transmittance of 80% or more over 750 nm, shows a reflectance of 50% or more over 900 to 1600 nm, shows a reflectance of about 40% even at 1600 to 1800 nm, and averages 5 in a wide infrared wavelength region.
It exhibited a reflection characteristic of 0% or more, which was in good agreement with the calculation result.

(Embodiment 3) The first multilayer film 31 and the second multilayer film 32 of the infrared reflection coating 3 have the same basic configuration as in the first embodiment, and the third multilayer film 33 is formed as [(L / 3.1) (M / 3.
2) (H / 1.6) (M / 3.2) (L / 3.
1)] The basic configuration of ⁴ . As the first to third low-refractive-index material layers (L), SiO ₂ having the same refractive index of 1.46 as in Examples 1 and ₂ was used as a vapor deposition source, and as the high-refractive-index material layer (H), 2.46 higher refractive index than in the case of 1, 2
The TiO ₂ showing a used as a deposition source. Further, the intermediate refractive index material layer (M) was formed by binary vapor deposition using both materials of SiO ₂ and TiO ₂ as vapor deposition sources and adjusting the refractive index to be 1.96. Further, the first multilayer film 31,
The design wavelengths λ ₃₁ , λ ₃₂ and λ ₃₃ for defining the optical film thickness of each multilayer film in the second multilayer film 32 and the third multilayer film 33 are 950 nm, 1280 nm and 1600, respectively.
nm.

FIG. 5 shows the spectral transmittance characteristics of the infrared reflective coating designed under the above conditions. The infrared reflective film formed on the glass bulb under the above conditions has a thickness of 380 nm to 780 n.
It shows good transmission characteristics of a transmittance of about 80% or more for all wavelengths of m, and shows a high reflection characteristic of 50% on average in a wide infrared region of 800 to 1800 nm, which agrees well with the calculation results. . Incidentally, it showed similar reflection characteristics using the same _Ta 2 _{O 5} and Examples 1 and 2 a high refractive index film (H).

Example 4 Infrared reflective coating 3 of Example 2
Without changing the basic configuration, the number of layers to be laminated, the lamination order in the multilayer film, the design wavelength, etc. in each of the first and second multilayer films 31 and 32. It was formed upside down. That is, the design wavelength λ is placed on the glass bulb 2.
₃₂ is 1280 nm, the second multilayer film 32 has a design wavelength λ
₃₁ was assumed to laminate the first multilayer film 31 was 950nm in order.

FIG. 6 shows the spectral transmittance characteristics of the infrared reflective coating designed under the above conditions. The infrared reflective film formed on the glass bulb under the above conditions has a thickness of 380 nm to 780 n.
m, showing good transmission characteristics of about 80% or more.
It exhibited high reflection characteristics in a wide infrared region from 00 to 1800 nm.

Example 5 A multilayer film of Example 1 was formed by reversing the lamination order. That is, the glass bulb 2
A third multilayer film 33 is formed on the surface, and then the second multilayer film 3 is formed.
2. The first multilayer film 31 was sequentially stacked. FIG. 7 shows the spectral transmittance characteristics in that case. Even in this case, 380 nm
It shows good transmission characteristics up to 780 nm,
It exhibited high reflection characteristics in a wide infrared region of 1800 nm, which was in good agreement with the calculation results.

As described above, according to the present invention, the optical thickness nd of the low-refractive index material and the high-refractive index material is conventionally λ / 4 as the infrared reflective coating formed on the glass bulb.
N · d = m · (λ / 4) (where m = 0,
1, 2,...) Are formed as multiple reflection films alternately stacked. However, in the present invention, in addition to the low refractive index material (L) and the high refractive index material (H), an intermediate refractive index material layer ( M) is added to the basic structure, and a multilayer film whose optical thickness nd is not an integral multiple of (λ / 4) but within a predetermined range is simply provided. Good reflection characteristics could be exhibited over a wide range as compared with those obtained by laminating multiple reflection films each having an integral multiple.

The infrared reflective coating of the present invention is used to form a multilayer film.
Film thickness of high refractive index material (H) layer: n_Hd_H= Λ_w
/ 4 is expressed as H, and an optical film of a low refractive index material (L) layer
Thickness: n _Ld_L= Λ_w/ 4 is represented by L, and an intermediate refractive index material
Film thickness of material (M) layer: n_Md_M= Λ_w/ 4 is M
(Where n_H, N_L, N_MIs a high refractive index material
Layer, low refractive index material layer, intermediate refractive index material layer refractive index,
d_H, D_L,d_MIs a high refractive index material layer, a low refractive index material layer,
The physical thickness of the intermediate refractive index material layer, w is λ at 1, 2, 3 ₁
Is the design wavelength of the first multilayer film, λ₂Is the design wave of the second multilayer
Long, λ₃Is the design wavelength of the third multilayer film).
This can be expressed as follows.

[(L / 2) H (L / 2)]^x[(L
/ A₂) (M / b₂) (H / c ₂) (M / b₂)
 (L / a₂)]^y[(L / a₃) (M / b₃)
(H / c₃) (M / b₃) (L / a₃)]^z

Here, x and y are integers of 2 or more, and z is
An integer of 0 or more (x = 0 means that the multilayer film is not formed)
2 <a₂, A₃<4, 2.5 <b₂, B
₃<4.5, 1 <c₂, C₃<2, first multilayer film, second multilayer film
Design wavelength λ of multilayer film and third multilayer film ₁, Λ₂, Λ₃Is 78
0 ≦ λ₁≦ 1200 nm, 1200 nm ≦ λ₂, Λ₃≤
2200 nm (however, λ₂≠ λ₃) And an intermediate refractive index material
Refractive index n of material (M)_MTo 0.32 (n_H-N_L) + N
_L<N_M<0.60 (n_H-N_L) + N_LAnd n_HIs
N greater than the refractive index of the optical article forming the coating_LIs an optical object
Shall be smaller than the product refractive index.

The order in which the first multilayer film 31, the second multilayer film 32, and the third multilayer film 33 are stacked is not limited to the order described in the above embodiment. The point is that at least the first multilayer film and the second multilayer film are formed to exhibit a transmittance of 70% or more of light in all wavelength ranges of visible light of at least 450 to 700 nm, and 950 to 950. 40% or more, with an average of 50%, of all wavelengths of infrared light at 1450 nm.
It is sufficient if the structure satisfies the optical characteristics of reflecting the light of not less than%. In this case, the low refractive index film (L) provided on the surface of the glass bulb base 2 so as to be in contact with the base may be omitted. Preferably, the design wavelength is 1200 nm or less on the surface of the glass substrate, and the low refractive index material layer (L)
When a first multilayer film made of SiO ₂ is formed and a second multilayer film and a third multilayer film having a design wavelength of 1200 nm or more are sequentially formed on the first multilayer film, the optical characteristics and the adhesion to the glass substrate are obtained. This is preferable because an infrared reflective coating having excellent properties can be formed.

Further, it is used in the first multilayer film 31.
A high refractive index material layer (H) and a low refractive index material layer (L);
Used in the two-layered film 32 or the third-layered film 33
High refractive index material layer (H), low refractive index material layer (L) and intermediate
If the refractive index material layer (M) is formed of the same material,
Only two types of sources need to be prepared.
Although simplified and preferable, for example, the stress
The low refractive index material layer (L) used in the first multilayer film and the second
Two materials different from the low refractive index material layer (L) used in the multilayer film
It may be formed by a material. Also, the intermediate refractive index
The example in which the material layer is formed by two-source vapor deposition has been described.
Other than N and SiO materials, showing a refractive index of around 1.8
May be used. The base is
If the refractive index is about 1.5, other materials than glass
Material, for example, Al with a refractive index of 1.63₂O ₃Crystal substrate
SiO with a folding ratio of 1.46₂It may be a crystalline substrate, etc.
Use a translucent material that has similar physical properties between the coating and the substrate
Is preferred.

In the above-described embodiment, an infrared reflective coating is formed on the surface of the glass bulb of the incandescent lamp. However, an incandescent lamp called a halogen bulb in which a trace amount of a halogen element is sealed together with an inert gas in the glass bulb. Even in the case of a light bulb, the refractive index of the inert gas, which is a medium radiated from the filament to the glass bulb, is about 1.0, which is almost equal to that of air. Reflection characteristics and good visible light transmittance characteristics can be obtained. In addition, the infrared reflective coating can be provided on the inner surface of the bulb or on the outside, but it is preferable to provide the infrared reflective coating on the outside because the film-forming step can be easily performed.

Furthermore, a cold mirror can be formed by forming an infrared reflective coating on an optical article other than a light bulb, for example, a mirror or the like, and can be applied to other optical articles other than a light bulb.

[0033]

As described above, according to the optical article provided with the infrared reflective coating of the present invention, high transmittance and non-coloring, which do not show coloring in the spectral transmission characteristics in the visible region as in the prior art. And at least 900n
It can have high reflection characteristics of 50% or more in a wide infrared region from m to 1500 nm.

When the infrared reflective coating is provided on a glass bulb of an incandescent light bulb, since it has a high visible range transmittance characteristic and a high infrared range reflective characteristic, the energy generated by the filament can be effectively applied to the filament. Can be returned. In particular, the radiant energy of incandescent bulbs is high1
Since it has a high reflectance in a wide range of 800 to 1800 nm centering around 000 nm, it has excellent effects such as further improving the efficiency of the incandescent lamp.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a main part of a light bulb provided with an infrared reflective coating of the present invention.

FIG. 2 is an explanatory diagram showing an enlarged main part provided with an infrared reflective coating.

FIG. 3 is an explanatory diagram showing the transmittance characteristics of the infrared reflective coating of Example 1.

FIG. 4 is an explanatory diagram showing the transmittance characteristics of the infrared reflective coating of Example 2.

FIG. 5 is an explanatory diagram showing the transmittance characteristics of the infrared reflective coating of Example 3.

FIG. 6 is an explanatory diagram showing the transmittance characteristics of the infrared reflective coating of Example 4.

FIG. 7 is an explanatory diagram showing transmittance characteristics of the infrared reflective coating of Example 5.

FIG. 8 is an explanatory view of a conventional light bulb provided with an infrared reflective coating.

FIG. 9 is an explanatory diagram showing, on an enlarged scale, a portion of the electric bulb of FIG. 8 where an infrared reflective coating is provided.

FIG. 10 is an explanatory diagram of transmittance characteristics of a conventional infrared reflective coating.

FIG. 11 is an explanatory diagram of transmittance characteristics of another conventional infrared reflective coating.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 bulb 2 glass bulb 3 infrared reflective coating 31 first multilayer film 32 second multilayer film 33 third multilayer film 90 incandescent lamp 91 glass bulb 92 base 93 filament 94 infrared reflective coating 95 high refractive index material layer 96 low refractive index material layer

Claims (6)

[Claims] 1. A method according to claim 1, wherein a plurality of substrates have a refractive index of about 1.5.
A translucent infrared reflective coating consisting of multiple layers of
In the optical article, the light-transmitting infrared-reflective coating is
Multi-layer structure of refractive index material (H) and low refractive index material (L)
First multilayer film, high refractive index material (H) and low refractive index material
(L) and an intermediate refractive index material (M) having an intermediate refractive index.
And a second multilayer film having a multilayer structure.
Film thickness of high refractive index material (H) layer: n_Hd_H= Λ_w
/ 4 is expressed as H, and an optical film of a low refractive index material (L) layer
Thickness: n_Ld_L= Λ_w/ 4 is represented by L, and an intermediate refractive index material
Film thickness of material (M) layer: n_Md_M= Λ_w/ 4 is M
(Where n_H, N_L, N_MIs a high refractive index material
Layer, low refractive index material layer, intermediate refractive index material layer refractive index,
d_H, D_L,d_MIs a high refractive index material layer, a low refractive index material layer,
Physical thickness of the intermediate refractive index material layer, λ_wIs the optical thickness setting
Total wavelength, λ₁Is the design wavelength of the first multilayer film, λ₂Is the
2 is the design wavelength of the multilayer film), the following conditions (a) to
With infrared reflective coating characterized by satisfying (d)
Optical articles. (A) The first multilayer film is an optical film in order from the substrate surface side.
The first layer having a thickness of (L / 2) and the first layer having an optical thickness of H
Three layers of two layers and a third layer having an optical thickness of (L / 2)
The basic structure is the structure, and the basic structure is repeated x cycles.
A film represented by the following equation. [(L / 2) H (L / 2)]^x, (X is an integer of 2 or more
(B) The second multilayer film is an optical film in order from the substrate surface side.
Thickness (L / a₂) And the optical thickness is (M / b)
₂), And the optical thickness is (H / c)₂)
3 layers, optical thickness (M / b₂4) layer and light
(L / a₂) Is based on the five-layer structure of the fifth layer
The following formula is obtained by repeating the basic configuration for y cycles.
The film that is expressed. [(L / a₂) (M / b₂) (H / c₂) (M /
b₂) (L / a₂)] ^y  Here, y is an integer of 2 or more, 2 <a₂<4, 2.5 <b
₂<4.5, 1 <c₂<2. (C) of the first multilayer film
Design wavelength λ₁, The design wavelength λ of the second multilayer film₂Is 780 ≦
λ₁ ≦ 1200 nm, 1200 nm ≦ λ₂≤2200nm
I do. (D) Refractive index n of the intermediate refractive index material (M)_MTo 0.32
(N_H-N_L) + N_L<N_M<0.60 (n_H-N_L)
+ N_LAnd 2. An infrared reflecting member formed on the optical article.
The film, together with the first multilayer film and the second multilayer film, has a high refractive index.
Intermediate between material (H), low refractive index material (L) and intermediate refractive index
Third multilayer film having a multilayer structure composed of a refractive index material (M)
And the following conditions together with the conditions (a) to (d):
2. The method according to claim 1, wherein (e) to (f) are satisfied.
Optical article with infrared reflective coating. (E) The third multilayer film is an optical film in order from the substrate surface side.
Thickness (L / a₃) And the optical thickness is (M / b)
₃), And the optical thickness is (H / c)₃)
3 layers, optical thickness (M / b₃4) layer and light
(L / a₃) Is based on the five-layer structure of the fifth layer
And the following formula obtained by repeating the basic configuration for z periods.
The film that is expressed. [(L / a₃) (M / b₃) (H / c₃) (M /
b₃) (L / a₃)] ^z  Here, z is an integer of 1 or more, 2 <a₃<4, 2.5 <b
₃<4.5, 1 <c₃<2. (F) Design wavelength λ of third multilayer film₃Is 1200 nm ≦ λ
₃≤2200 nm (where λ₂≠ λ₃). 3. The infrared reflective coating, wherein a first multilayer film and a second multilayer film are laminated, wherein the design wavelength λ ₁ of the first multilayer film is about 950 nm, and the design wavelength λ ₃ of the second multilayer film is The optical article with an infrared reflective coating according to claim 1, wherein the thickness is about 1500 nm. 4. The method according to claim 1, wherein the infrared reflective coating comprises a first multilayer film,
The second multilayer film and the third multilayer film are successively laminated. The first multilayer film has a design wavelength λ ₁ of about 950 nm, the second multilayer film has a design wavelength λ ₂ of about 1280 nm, and the third multilayer film has a design wavelength λ ₂ of about 1280 nm. infrared reflective coating with an optical article according to claim 2, wherein the design wavelength lambda ₃ is about 1600 nm. 5. The infrared reflective film according to claim 1, wherein the infrared reflective film is a multilayer film in which a low refractive index material layer (L) in contact with the substrate is omitted. Optical article with infrared reflective coating. 6. The bulb with an infrared reflective coating according to claim 1, wherein the base is a bulb of a bulb.