JP2003043202A - Antireflection film and optical parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antireflection film having high antireflective performance in a wide band from the UV region to the visible region and the IR region. SOLUTION: A low refractive index material is deposited to form the first and eighth layers from the substrate side, a middle refractive index material is deposited to form the second, fourth and sixth layers, and a high refractive index material is deposited to form the third, fifth and seventh layers. The optical film thickness nd of each layer is controlled with respect to the design wavelength λ to satisfy (0.9 to 2.4)×λ/4 for the first layer, (0.9 to 1.2)×λ/4 for the second layer, (0.27 to 0.50)×λ/4 for the third layer, (0.17 to 0.27)×λ/4 for the fourth layer, (1.34 to 2.14)×λ/4 for the fifth layer, (0.35 to 0.45)×λ/4 for the sixth layer, (0.26 to 0.38)×λ/4 for the seventh layer and (1.03 to 1.13)×λ/4 for the eighth layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antireflection film applied to optical parts used in the ultraviolet, visible and infrared regions, and an optical part formed with this antireflection film.

[0002]

2. Description of the Related Art Generally, an antireflection film is provided on the surface of optical components such as lenses and prisms. Its main purpose is
It is to improve the transmittance of the entire optical device composed of a large number of optical parts, and particularly to improve the brightness and visibility of an image by suppressing reflection in the visible range. Since many optical devices used so far are used in the visible range or a wavelength range narrower than that, it is sufficient for the antireflection film to be able to reduce the reflectance in such a narrow wavelength range.

However, in recent years, with the advent of optical equipment used in a wider wavelength range, an antireflection film in a wavelength range corresponding to optical components used therein has been required. A conventional antireflection film applicable in a wide wavelength range is disclosed in, for example, Japanese Patent Publication No. 2711697. According to this invention, Ti is used as the vapor deposition material.
By adopting an eight-layer structure using three kinds of materials of O ₂ , SiO ₂ , and MgF ₂ , a low reflectance of 0.8% or less is realized in a wide band from the visible region to the infrared region.

[0004]

By the way, in the recent optical equipment, in addition to the visible region (400 nm to 700 nm) and the infrared region (700 nm to 900 nm), the near ultraviolet region (340 nm).
(nm to 400 nm), there is a demand for an antireflection film or an optical component having high antireflection performance and transmittance. For example, in a microscope, in addition to improving the visibility in the visible range for visual observation, since an observation method using light in the ultraviolet region or infrared region as a probe is used in parallel, more specifically, in the ultraviolet region, In order to observe visible light emitted when light is irradiated on an object and excited, and infrared light for fluorescence detection, optical parts and antireflection films used for this are also monitored from the ultraviolet range. There is a growing demand for high transmittance and antireflection performance over a wide band in the infrared region.

However, the above-mentioned conventional antireflection film uses TiO ₂ which has a strong light absorption at a wavelength of 400 nm or less, and the optical component to which this is applied is used because of its low transmittance in the ultraviolet region. There is a problem that you cannot do it.

The present invention has been made in consideration of such problems, and an antireflection film having a high antireflection property in a wide band from the ultraviolet region to the visible region and further to the infrared region, and such a reflection film. It is an object of the present invention to provide an optical component having a high transmittance and provided with an anti-reflection film.

[0007]

In order to solve the above-mentioned problems, the antireflection film of the invention of claim 1 is an antireflection film provided on a base material, and is the first and eighth antireflection films counted from the base material side. The low refractive index material is deposited on the layers, the intermediate refractive index material is deposited on the second, fourth, sixth layers, and the high refractive index material is deposited on the third, fifth, and seventh layers, respectively. For the design wavelength λ,
The first layer is (0.9 to 2.4) × λ / 4, and the second layer is (0.
9-1.2) × λ / 4, the third layer is (0.27-0.5)
0) × λ / 4, and the fourth layer is (0.17 to 0.27) × λ /
4, the fifth layer is (1.34 to 2.14) × λ / 4, the sixth layer is (0.35 to 0.45) × λ / 4, and the seventh layer is (0.2
6 to 0.38) × λ / 4, the eighth layer is (1.03 to 1.1)
3) × λ / 4.

According to the antireflection film of the present invention, it is possible to have a high antireflection effect in a wide wavelength range from the ultraviolet region to the infrared region by defining the refractive index and the film thickness of the film forming material constituting each layer. it can.

It is also possible to shift or widen the antireflection wavelength band by changing the design wavelength λ. For example, if λ = 400 nm, 300 n
In the wavelength range from m to 800 nm, if λ = 480 nm, then 3
In the wavelength range of 40 nm to 1000 nm, if λ = 560 nm, the antireflection performance can be obtained in the wavelength range of 400 nm to 1150 nm.

As a low refractive index material, it has an absorption in the ultraviolet region.
SiO with low yield_TwoAnd MgF_TwoCan be used
But the first layer is SiO_Two, The lower refractive index of the eighth layer
MgF _TwoIt is preferable to use.

The material of the base material may be a crystal material, plastic or the like other than glass. Also, the shape of the base material is a flat plate shape,
It can be applied to any shape such as a lens shape and a prism shape. The method for forming the antireflection film is not particularly limited and may be a vacuum deposition method, a sputtering method, an ion plating method, or the like.

An antireflection film according to a second aspect of the present invention is an antireflection film provided on a base material, wherein the low refractive index material is formed in the eighth layer and the second, fourth, and sixth layers are counted from the base material side. A high refractive index material is deposited on each of the first, third, fifth, and seventh layers of the intermediate refractive index material, and the optical thickness nd of each layer is (0 .05 to 0.4) × λ / 4, second
The layer is (0.2 to 1.3) × λ / 4, and the third layer is (0.2 to 1.3)
0.7) × λ / 4, the fourth layer is (0.1-0.5) × λ /
4, the fifth layer is (1.8 to 2.6) × λ / 4, the sixth layer is (0.2 to 0.5) × λ / 4, and the seventh layer is (0.1 to 0.
5) × λ / 4, and the eighth layer is (0.9 to 1.2) × λ / 4.

According to the antireflection film of the present invention, it is possible to have a high antireflection effect in a wide wavelength range from the ultraviolet region to the infrared region by defining the refractive index and the film thickness of the film forming material forming each layer. it can.

As the low-refractive-index material for the eighth layer, SiO ₂ or MgF ₂ which has little absorption in the ultraviolet region can be used, but it is preferable to use MgF ₂ having a lower refractive index. The base material has a good refractive index of 1.5 to 1.9, and the material thereof may be a crystal material, plastic, or the like other than glass. Further, the shape of the base material can be applied to any shape such as a flat plate shape, a lens shape, and a prism shape.
The method for forming the antireflection film is not particularly limited and may be a vacuum deposition method, a sputtering method, an ion plating method, or the like.

The antireflection film of the invention of claim 3 is the same as that of claim 1.
Or the antireflection film according to 2, wherein the high refractive index material is HfO ₂ , ZrO ₂ , Ta ₂ O ₅ , LaTi _x O _y ,
It is characterized by being any one of Y ₂ O ₃ or a mixture thereof.

HfO ₂ , ZrO ₂ , which are high refractive index materials,
Since Ta ₂ O ₅ , LaTi _x O _y , and Y ₂ O ₃ are materials that have little absorption even in the ultraviolet region, the antireflection film formed of them has a wide wavelength range from the ultraviolet region to the infrared region. It can have a high antireflection effect.

Further, by selecting the material, it is possible to reduce the reflectance in the ultraviolet region or to reduce the reflectance in the entire wide wavelength region. For example, when HfO ₂ is used, antireflection performance can be obtained from the deep ultraviolet region of about 230 nm. When ZrO ₂ is used, the antireflection performance at a short wavelength is inferior to that of HfO _2, but it exhibits sufficient antireflection performance in the ultraviolet region of 320 nm or more, and is inexpensive, so the manufacturing cost of the antireflection film is suppressed be able to.
When Ta ₂ O ₅ and LaTi _x O _y are used, about 350
It has sufficient antireflection performance in the ultraviolet region of nm or more, and is further advantageous in terms of cost because it can stably form a film and can be repeatedly used as a film forming material. Furthermore, Hf
The refractive index is higher than that of O ₂ and ZrO _2, and there is an advantage that good optical characteristics can be obtained.

The antireflection film of the invention of claim 4 is the antireflection film of claim 1.
The antireflection film according to any one of items 1 to 3, wherein the intermediate refractive index material is any one of Al ₂ O ₃ and CeF ₃ , or a mixture thereof.

Al ₂ O ₃ and CeF which are intermediate refractive index materials
_{Since 3} is a material that has little absorption even in the ultraviolet region, the antireflection film formed of these has a high antireflection effect in a wide wavelength range from the ultraviolet region to the infrared region.
When forming an antireflection film having a wider antireflection band on the ultraviolet region side, it is desirable to use Al ₂ O ₃ .

The optical component of the invention according to claim 5 is the optical component according to claim 1.
The antireflection film according to any one of 4) is provided on the base material.

According to this optical component, since the antireflection film having a high antireflection effect is formed in a wide wavelength range from the ultraviolet region to the infrared region, it has a high transmittance in a wide wavelength range. Therefore, it can be applied to an optical device used in a wide wavelength range from the ultraviolet region to the infrared region. In addition to glass, the material of the substrate may be a crystalline material, plastic, or the like. Further, it is possible to obtain optical components of any shape such as a flat plate shape, a lens shape and a prism shape.

[0022]

<First Embodiment> Refractive index 1.44
On the above base material, the design wavelength λ was set to 480 nm, and as the first layer on the base material side, SiO as the low refractive index material was formed as shown in Table 1.
₂ is Al as the intermediate refractive index material in the second, fourth and sixth layers.
₂ O ₃ is added to the third, fifth and seventh layers as T as a high refractive index material.
a ₂ O ₅ was added to the eighth layer as a low refractive index material MgF ₂
Was used to form an antireflection film.

In this embodiment, the film is formed by the ion plating method in which the base material is heated to about 250 ° C. and RF power is applied to perform the evaporation. However, the vacuum evaporation method, the sputtering method, and the ion assisted evaporation method are used. An antireflection film having equivalent characteristics can be formed by other methods such as the above.

FIG. 1 shows the spectral reflectance characteristics of this antireflection film. From 340 nm in the ultraviolet region to 100 in the infrared region
It has extremely good antireflection performance in the range of 0 nm. Further, the optical component having the antireflection film of the present embodiment on both sides or one side exhibited extremely good transmittance in a wide band from the ultraviolet region to the infrared region.

In this embodiment, Ta ₂ O ₅ is used as the high refractive index material because it has a high refractive index and allows stable film formation and repeated use of the film forming material. Therefore, good optical characteristics are obtained. The antireflection film can be formed at low cost.

In this embodiment, SiO ₂ and MgF ₂ are used as the low refractive index material, but the material is not limited to this. Although _Al 2 _{O 3} was used as the intermediate-refractive index material, the same effects can be obtained by using a mixture of CeF _{3, Al} 2 _{O 3,} or _the and CeF _3. Although Ta ₂ O ₅ is used as the high refractive index material, HfO ₂ , ZrO ₂ , La
Similar effects can be obtained by using Ti _x O _y , Y ₂ O ₃ or a mixture thereof.

<Embodiment 2> An antireflection film having the same film structure as that of Embodiment 1 as shown in Table 1 was formed on a substrate having a refractive index of 1.50 with a design wavelength λ of 480 nm. . The spectral reflectance characteristic of this antireflection film is shown in FIG. It has extremely good antireflection performance in the range of 340 nm which is the ultraviolet region to 1000 nm which is the infrared region.

Further, the optical component having the antireflection film of this embodiment on both sides or one side exhibited extremely good transmittance in a wide band from the ultraviolet region to the infrared region. Other functions and effects are similar to those of the first embodiment.

<Third Embodiment> An antireflection film having the same film structure as that of the first embodiment as shown in Table 1 is formed on a base material having a refractive index of 1.52 with a design wavelength λ of 480 nm. . The spectral reflectance characteristic of this antireflection film is shown in FIG. It has extremely good antireflection performance in the range of 340 nm which is the ultraviolet region to 1000 nm which is the infrared region.

Further, the optical component having the antireflection film of this embodiment on both sides or one side showed a very good transmittance in a wide band from the ultraviolet region to the infrared region. Other functions and effects are similar to those of the first embodiment.

<Embodiment 4> An antireflection film having the same film structure as that of Embodiment 1 as shown in Table 1 was formed on a base material having a refractive index of 1.56 with a design wavelength λ of 480 nm. . The spectral reflectance characteristic of this antireflection film is shown in FIG. It has extremely good antireflection performance in the range of 340 nm which is the ultraviolet region to 1000 nm which is the infrared region.

Further, the optical component having the antireflection film of this embodiment on both sides or one side exhibited extremely good transmittance in a wide band from the ultraviolet region to the infrared region. Other functions and effects are similar to those of the first embodiment.

Table 2 shows the maximum reflectance or average reflectance in each wavelength band in the above-described first to fourth embodiments (when the base material has a different refractive index). It has a good antireflection property in the range of 340 nm which is the ultraviolet region to 1000 nm which is the infrared region, and in particular, in the range of 340 nm to 900 nm, the reflectance is 1% or less, which is an extremely good antireflection property.

[0034]

[Table 1]

[0035]

[Table 2]

<Embodiment 5> With a design wavelength λ of 480 nm on a base material having a refractive index of 1.44, as shown in Table 3, the first layer from the base material side is made of SiO ₂ as a low refractive index material. To
Al ₂ O ₃ as an intermediate refractive index material for the second, fourth and sixth layers
On the third, fifth and seventh layers as HfO ₂ as a high refractive index material.
Then, an antireflection film having a film structure using MgF ₂ as a low refractive index material was formed as the eighth layer.

In this embodiment, the film is formed by the vacuum evaporation method in which the base material is heated to about 250 ° C., but other methods such as the sputtering method, the ion plating method and the ion assisted evaporation method can also be used. An antireflection film having equivalent properties can be formed. The spectral reflectance characteristic of this antireflection film is shown in FIG. It has extremely good antireflection performance in the range of 340 nm which is the ultraviolet region to 1000 nm which is the infrared region.

Further, the optical component having the antireflection film of this embodiment applied on both sides or one side exhibited a very good transmittance in a wide band from the ultraviolet region to the infrared region.

In this embodiment, SiO ₂ and MgF ₂ are used as the low refractive index material, but the material is not limited to this. Although _Al 2 _{O 3} was used as the intermediate-refractive index material, the same effects can be obtained by using a mixture of CeF _{3, Al} 2 _{O 3,} or _the and CeF _3.

<Embodiment 6> HfO ₂ of Embodiment 5
Instead of this, a mixture of ZrO ₂ and Ta ₂ O ₅ was used, and an antireflection film having a film configuration as shown in Table 3 was formed on a substrate having a refractive index of 1.44. The spectral reflectance characteristic of this antireflection film is shown in FIG. From 340 nm which is the ultraviolet region to 1 which is the infrared region
It has extremely good antireflection performance in the range of 000 nm.

Further, the optical component having the antireflection film of this embodiment on both sides or one side exhibited extremely good transmittance in a wide band from the ultraviolet region to the infrared region. Other operational effects are similar to those of the fifth embodiment.

<Embodiment 7> HfO ₂ of Embodiment 5
Instead, LaTiO ₃ was used, and an antireflection film having a film configuration as shown in Table 3 was formed on a substrate having a refractive index of 1.44. The spectral reflectance characteristic of this antireflection film is shown in FIG. It has extremely good antireflection performance in the range of 340 nm which is the ultraviolet region to 1000 nm which is the infrared region.

Further, the optical component having the antireflection film of this embodiment on both sides or one side exhibited a very good transmittance in a wide band from the ultraviolet region to the infrared region. Other operational effects are similar to those of the fifth embodiment.

Table 4 shows the maximum reflectance or average reflectance in each wavelength band in the above fifth to seventh embodiments (in the case where the high-layer folding rate materials are different). Good antireflection characteristics are shown in the range of 340 nm which is the ultraviolet region to 1000 nm which is the infrared region.

[0045]

[Table 3]

[0046]

[Table 4]

<Embodiment 8> On a base material having a refractive index of 1.52, the design wavelength λ is set to 480 nm, and as shown in Table 5, the first layer from the base material side is made of SiO ₂ as a low refractive index material. To
Al ₂ O ₃ as an intermediate refractive index material for the second, fourth and sixth layers
On the third, fifth and seventh layers as Ta ₂ O as a high refractive index material.
₅ was used as the eighth layer to form an antireflection film having a film structure using MgF ₂ as a low refractive index material.

In this embodiment, the film is formed by the vacuum evaporation method in which the base material is heated to about 250 ° C. and oxygen is introduced, but other methods such as the sputtering method, the ion plating method and the ion assisted evaporation method are used. An antireflection film having equivalent characteristics can be formed also by the method.

The spectral reflectance characteristic of this antireflection film is shown in FIG. From 340 nm in the ultraviolet region to 100 in the infrared region
It has extremely good antireflection performance in the range of 0 nm.

Further, the optical component of this embodiment provided with the antireflection film on both sides or one side showed a very good transmittance in a wide band from the ultraviolet region to the infrared region.

In this embodiment, SlO ₂ and MgF ₂ are used as the low refractive index material, but the material is not limited to this. Although _Al 2 _{O 3} was used as the intermediate-refractive index material, the same effects can be obtained by using a mixture of CeF _{3, Al} 2 _{O 3,} or _the and CeF _3.

<Embodiment 9> Ta ₂ O of Embodiment 8
The HfO ₂ using in place of ₅ was formed an antireflection film of a film structure as shown in Table 5 on a substrate of refractive index 1.52. The spectral reflectance characteristic of this antireflection film is shown in FIG. It has extremely good antireflection performance in the range of 340 nm which is the ultraviolet region to 1000 nm which is the infrared region.

Further, the optical component having the antireflection film of this embodiment on both sides or one side exhibited extremely excellent transmittance in a wide band from the ultraviolet region to the infrared region. Other operational effects are similar to those of the eighth embodiment.

Table 6 shows the maximum reflectance or average reflectance in each wavelength band in the above eighth and ninth embodiments (when the refractive index of the base material is 1.52 and the high refractive index material is different). From 340 nm in the ultraviolet region to 10 in the infrared region
Good antireflection characteristics are shown in the range of 00 nm.

[0055]

[Table 5]

[0056]

[Table 6]

<Embodiment 10> On a base material having a refractive index of 1.52, the design wavelength λ is set to 460 nm, and as shown in Table 7, the second, fourth and sixth layers from the base material side have intermediate refractive index materials. the _Al 2 _{O 3} as a of _Ta 2 _{O 5 which has} a a high refractive index material to a 1,3,5,7-layer, the eighth-layer film structure using MgF ₂ as a low refractive index material The antireflection film of No. 1 was formed.

In this embodiment, 10 ⁻⁴ to 10 ⁻⁶
The film was formed by the vacuum evaporation method under the vacuum of Torr.
An antireflection film having equivalent characteristics can be formed by another method such as a sputtering method, an ion plating method, or ion assisted vapor deposition.

FIG. 10 shows the spectral reflectance characteristics of this antireflection film.
Shown in. From 340 nm in the ultraviolet region to 90 in the infrared region
It has an extremely good antireflection property with a reflectance of 1.0% or less in the range of 0 nm.

Further, the optical component having the antireflection film of this embodiment on both sides or one side showed extremely excellent transmittance in a wide band from the ultraviolet region to the infrared region.

In this embodiment, Ta ₂ O ₅ is used as the high refractive index material because it has a high refractive index and allows stable film formation and repeated use of the film forming material. Therefore, good optical characteristics can be obtained. An antireflection film can be formed at low cost.

In this embodiment, the low refractive index material
As MgF_TwoHowever, the present invention is not limited to this.
Also, as an intermediate refractive index material, Al_TwoO_ThreeWas used, but C
eF _ThreeAnd Al_TwoO_ThreeAnd CeF_ThreeThe same with a mixture of
The same effects can be obtained and Ta as a high refractive index material_TwoO₅
Was used, but HfO_Two, ZrO_Two, LaTi_xO_y, Y
_TwoO_ThreeSimilar effects can be obtained by using or a mixture of these.
To be

<Embodiment 11> An antireflection film having the same film configuration as that of Embodiment 10 as shown in Table 7 was formed on a substrate having a refractive index of 1.61 with a design wavelength λ of 460 nm. . The spectral reflectance characteristic of this antireflection film is shown in FIG.
In the range of 340 nm which is the ultraviolet region to 900 nm which is the infrared region, the reflectance is 1.0% or less, which is extremely good antireflection performance.

Further, the optical component having the antireflection film of this embodiment applied on both sides or one side showed a very good transmittance in a wide band from the ultraviolet region to the infrared region. Other operational effects are similar to those of the tenth embodiment.

<Embodiment 12> An antireflection film having the same film structure as that of Embodiment 10 as shown in Table 7 was formed on a substrate having a refractive index of 1.79 with a design wavelength λ of 460 nm. . The spectral reflectance characteristic of this antireflection film is shown in FIG.
In the range of 340 nm which is the ultraviolet region to 900 nm which is the infrared region, the reflectance is 1.0% or less, which is extremely good antireflection performance.

Further, the optical component having the antireflection film of this embodiment applied on both sides or one side exhibited a very good transmittance in a wide band from the ultraviolet region to the infrared region. Other operational effects are similar to those of the tenth embodiment.

[0067]

[Table 7]

<Embodiment 13> On a base material having a refractive index of 1.56, the design wavelength λ is set to 460 nm, and as shown in Table 8, the second, fourth and sixth layers from the base material side have intermediate refractive index materials. the _Al 2 _{O 3} as a, M of the HfO ₂ as a high refractive index material to a 1,3,5,7-layer, as a low refractive index material to the eighth layer
An antireflection film having a film structure using gF ₂ was formed.

In this embodiment, 10 ⁻⁴ to 10 ⁻⁶
The film was formed by the ion assisted vapor deposition method under the vacuum of Torr, but the antireflection film having the same characteristics can be formed by other methods such as the vacuum vapor deposition method, the sputtering method and the ion plating method. .

FIG. 13 shows the spectral reflectance characteristics of this antireflection film.
Shown in. Ultraviolet region 310 nm to visible region 70
The reflectance is 1.0% or less in the range of 0 nm, and the reflectance is 1.5% or less in the range of 310 nm to 900 nm which is the infrared region, which is extremely good antireflection performance.

Further, the optical component having the antireflection film of this embodiment on both sides or one side showed extremely excellent transmittance in a wide band from the ultraviolet region to the infrared region.

In this embodiment, since HfO ₂ having a transmission band in the deep ultraviolet region is used as the high refractive index material, it is possible to form an antireflection film having an antireflection property up to a shorter wavelength.

In this embodiment, MgF ₂ was used as the low refractive index material, but the material is not limited to this. Also,
Although Al ₂ O ₃ was used as the intermediate refractive index material, CeF ₃
Similar effects can be obtained by using a mixture of Al ₂ O ₃ and CeF ₃ . HfO ₂ was used as the high refractive index material, but Ta ₂ O ₅ , ZrO ₂ , LaTi _x O _y , and Y ₂ O were used.
Similar effects can be obtained by using ₃ or a mixture thereof.

<Embodiment 14> An antireflection film having the same film structure as that of Embodiment 13 as shown in Table 8 was formed on a base material having a refractive index of 1.61 with a design wavelength λ of 460 nm. . The spectral reflectance characteristics of this antireflection film are shown in FIG.
The reflectance is 1.0% or less in the range of 310 nm which is the ultraviolet region to 700 nm which is the visible region, and the reflectance is 1.5% or less even in the range of 310 nm which is the infrared region of 900 nm, which is an extremely excellent antireflection property. There is.

Further, the optical component having the antireflection film of this embodiment on both sides or one side exhibited extremely excellent transmittance in a wide band from the ultraviolet region to the infrared region. Other operational effects are similar to those of the thirteenth embodiment.

<Embodiment 15> An antireflection film having the same film structure as that of Embodiment 13 as shown in Table 8 was formed on a substrate having a refractive index of 1.79 with a design wavelength λ of 460 nm. . The spectral reflectance characteristic of this antireflection film is shown in FIG.
The reflectance is 1.0% or less in the range of 310 nm which is the ultraviolet region to 700 nm which is the visible region, and the reflectance is 1.5% or less even in the range of 310 nm which is the infrared region of 900 nm, which is an extremely excellent antireflection property. There is.

Further, the optical component having the antireflection film of this embodiment on both sides or one side exhibited extremely excellent transmittance in a wide band from the ultraviolet region to the infrared region. Other operational effects are similar to those of the thirteenth embodiment.

[0078]

[Table 8]

[0079]

As described above, according to the inventions of claims 1 to 4, it is possible to obtain an antireflection film having a high antireflection property in a wide band from the ultraviolet region to the visible region and further to the infrared region. .

According to the invention of claim 5, by providing the antireflection film of the invention of claims 1 to 4, it is possible to obtain an optical component having a high transmittance in a wide band from the ultraviolet region to the infrared region.

[Brief description of drawings]

FIG. 1 is a spectral reflectance characteristic diagram of the first embodiment.

FIG. 2 is a spectral reflectance characteristic diagram of the second embodiment.

FIG. 3 is a spectral reflectance characteristic diagram of the third embodiment.

FIG. 4 is a spectral reflectance characteristic diagram of the fourth embodiment.

FIG. 5 is a spectral reflectance characteristic diagram of the fifth embodiment.

FIG. 6 is a spectral reflectance characteristic diagram of the sixth embodiment.

FIG. 7 is a spectral reflectance characteristic diagram of the seventh embodiment.

FIG. 8 is a spectral reflectance characteristic diagram of the eighth embodiment.

FIG. 9 is a spectral reflectance characteristic diagram of the ninth embodiment.

FIG. 10 is a spectral reflectance characteristic diagram of the tenth embodiment.

FIG. 11 is a spectral reflectance characteristic diagram of the eleventh embodiment.

FIG. 12 is a spectral reflectance characteristic diagram of the twelfth embodiment.

FIG. 13 is a spectral reflectance characteristic diagram of the thirteenth embodiment.

FIG. 14 is a spectral reflectance characteristic diagram of the fourteenth embodiment.

FIG. 15 is a spectral reflectance characteristic diagram of the fifteenth embodiment.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Norio Wada             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. (72) Inventor Nobuyoshi Toyohara             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. (72) Inventor Ken Kawamata             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. (72) Inventor Tadashi Watanabe             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. F-term (reference) 2K009 AA09 CC03 DD04 DD07                 4F100 AA19D AA19E AA20 AA21E                       AA27E AR00B AR00C AR00D                       AR00E AT00A BA05 BA07                       BA08 BA10A BA10E BA25                       EH66 EH662 GB90 JD06                       JN06 JN06B JN06C JN06D                       JN06E JN18B JN18C JN18D                       JN18E                 4G059 AA11 AB11 AC04 EA01 EA09                       EB02 GA02 GA04 GA12                 4K029 AA09 AA11 BA43 BA48 BB02                       BC08 BD00 CA03 DD02

Claims (5)

[Claims] 1. An antireflection film provided on a substrate, comprising:
Counting from the substrate side, the low refractive index material is used for the first and eighth layers,
The intermediate refractive index material is deposited on the fourth and sixth layers, and the high refractive index material is deposited on the third, fifth and seventh layers, and the optical film thickness nd of each layer is the first layer with respect to the design wavelength λ. Is (0.9-2.
4) × λ / 4, the second layer is (0.9 to 1.2) × λ / 4,
The third layer is (0.27 to 0.50) × λ / 4, the fourth layer is (0.17 to 0.27) × λ / 4, and the fifth layer is (1.34).
~ 2.14) x λ / 4, the sixth layer is (0.35-0.4)
5) × λ / 4, the seventh layer is (0.26 to 0.38) × λ /
The fourth and eighth layers are (1.03 to 1.13) × λ / 4, which is an antireflection film. 2. An antireflection film provided on a base material, comprising:
Counting from the base material side, a low refractive index material is used for the eighth layer,
An intermediate refractive index material is deposited on the 6th layer, and a high refractive index material is deposited on the 1st, 3rd, 5th, and 7th layers, and the optical film thickness nd of each layer is the first layer with respect to the design wavelength λ. Is (0.05 ~
0.4) × λ / 4, the second layer is (0.2 to 1.3) × λ /
4, the third layer is (0.2 to 0.7) × λ / 4, the fourth layer is (0.1 to 0.5) × λ / 4, and the fifth layer is (1.8 to 2.
6) × λ / 4, the sixth layer is (0.2 to 0.5) × λ / 4,
The seventh layer is (0.1-0.5) × λ / 4, and the eighth layer is (0.
9 to 1.2) × λ / 4, which is an antireflection film. 3. The high refractive index material is HfO ₂ , Zr.
_{O 2, Ta 2 O 5,} LaTi x O y, claim 1, characterized in that either or a mixture of these _Y 2 _{O 3}
Alternatively, the antireflection film described in 2. 4. The intermediate refractive index material is Al ₂ O ₃ , Ce.
The antireflection film according to any one of claims 1 to 3, which is any one of F ₃ and a mixture thereof. 5. An optical component comprising the antireflection film according to claim 1 provided on a base material.