JP2003098308A - Optical parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide optical parts using a plastic substrate, having a multilayer antireflection film deposited thereon and having high adhesion strength of the multilayer antireflection film and high antireflection property by the multilayer antireflection film as well as preferable durability. SOLUTION: The optical parts have a substrate made of an acrylic resin material, a thick silicon oxide film formed on the surface of the substrate, and a multilayer antireflection film formed on the silicon oxide film by alternately depositing at least each one layer of a low refractive index material layer and a high refractive index material layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical part such as a lens.
In detail, it belongs to the technical field of products, and more specifically, multilayer reflection with strong adhesion
The present invention relates to an optical component having a prevention film and excellent in durability. [0002] 2. Description of the Related Art As materials for optical components such as lenses,
Since then, glass has been used. On the other hand, lightweight and low cost
In recent years,
Made of limethyl methacrylate (PMMA), etc.
Plastic parts made of plastic are also widely used. These lights
One of the characteristics widely required for academic parts is anti-light reflection
Is high (low light reflectivity) on the surface of optical components
In many cases, a (light) antireflection film is formed. An antireflection film formed on the surface of an optical component;
As magnesium fluoride (MgF₂) Etc.
Single-layer films formed using materials are widely used,
Low refractive index material as anti-reflection film with higher anti-reflection properties
Alternately, the layer made of the material and the layer made of the high refractive index material,
A multilayer antireflection film (ma
Lucticoat antireflection film) is known. However, many
Plastic optical parts with a layer antireflection coating
Plate (ie plastic optical component) and multilayer antireflection
Low adhesion to the film, i.e. insufficient durability
There is a problem that. [0004] SUMMARY OF THE INVENTION A multilayer antireflection film is one of
Generally, it is formed by a vapor phase film forming method such as vacuum deposition. Vapor phase
In the film method, the temperature of the substrate rises without heating the substrate.
Then, the substrate expands. Especially for multilayer anti-reflection coatings
In consideration of the properties, etc., multiple layers are continuously formed and high
Refractive materials are usually deposited with higher energy
As a result, the substrate temperature increases, and the substrate expands considerably.
The Therefore, a large substrate after the formation of the multilayer antireflection film is large.
When taken out into the air, the substrate is cooled rapidly and shrinks.
The However, plastic substrates, in particular,
A substrate made of an acrylic material typified by PMMA,
With the multilayer antireflection film formed on the substrate, the thermal expansion coefficient is
Unlikely, the coefficient of thermal expansion of the multilayer antireflection film deposited on the substrate
Is smaller than the substrate. Therefore, the film formation is completed and the atmosphere
Multilayer due to shrinkage of the substrate when taken out
The antireflection film cannot follow, and the multilayer antireflection film
It takes damage and has a large distortion. So
As a result, the adhesion of the multilayer antireflection film is reduced, and
The wearing force gradually decreases with time.
Greatly improves the durability of optical components with multilayer antireflection coatings.
It will decline. The object of the present invention is to overcome the problems of the prior art.
Excellent solution for light weight, low cost, productivity, etc.
A multilayer antireflection film is formed on a plastic substrate.
The optical component has a high adhesion strength to the multilayer antireflection film.
In addition to high anti-reflection properties due to the multilayer anti-reflection film,
An object of the present invention is to provide an optical component having favorable durability. [0007] To achieve the above object
The optical component of the present invention is a substrate made of an acrylic resin material.
And a thick silicon oxide film formed on the surface of this substrate
And a low refractive index material formed on this silicon oxide film.
Alternate layers and layers of high refractive index materials.
A multilayer antireflection film formed at least one layer at a time
An optical component is provided. [0008] BEST MODE FOR CARRYING OUT THE INVENTION
Based on the preferred embodiment shown in the accompanying drawings,
Light up. FIG. 1 is a conceptual diagram of an example of the optical component of the present invention.
Indicates. The optical component 10 of the present invention is an optical component that becomes a substrate.
12 (hereinafter referred to as substrate 12) and the surface of this substrate 12
Formed on the silicon oxide film 14 and the silicon oxide film 14.
The formed multilayer antireflection film 16 (hereinafter referred to as the antireflection film 16).
And). In the illustrated example,
The anti-reflection film 16 includes a high refractive index layer 18 made of a high refractive index material.
(18a and 18b) and low flexure made of low refractive index material
The folding layers 20 (20a and 20b) are not alternately arranged in two layers.
A four-layer structure is formed by stacking two layers. In the present invention, the substrate 12 is made of acrylic.
In particular, PMMA
(Polymethylmethacrylate) is preferably used
It is. In the present invention, the substrate 12 (ie, the
There are no other limitations on the optical component 10),
Various known optical components are available. Specifically, each
Various lenses, various filters, various screens, height
Examples include child films and optical substrates. In the optical component 10 of the present invention, the substrate 12
A silicon oxide film 14 is formed on the surface. Optical component 1
0, the silicon oxide film 14 is formed of the substrate 12 and the antireflection film.
Acts as an adhesion layer to improve adhesion with 16
Film, preferably silicon monoxide (SiO) film forming material
(Evaporation source) is a film formed by vacuum evaporation
The In the present invention, this silicon oxide film 14 is
During film formation by vacuum deposition, oxygen is introduced into the film formation system.
The film is given elasticity by
More preferable. As described above, a plastic substrate, especially
Multi-layer reflection on a substrate made of acrylic material such as PMMA
When the protective film is formed, the thermal expansion coefficient of both
Due to differences, due to cooling when the atmosphere is opened after film formation
Multilayer antireflection coating follows large shrinkage / deformation of substrate
The multilayer anti-reflective coating is damaged,
It will have distortion. As a result, the multilayer antireflection film
The adhesion decreases and this adhesion increases with time.
Therefore, the optical component having a multilayer antireflection film is
It does not meet the required properties in terms of durability. On the other hand, the optical component 10 of the present invention is dense.
A silicon oxide film 14 acting as a deposition layer, and
By increasing the film thickness, the antireflection film 16 and the substrate 12 are increased.
High durability with sufficient adhesion with
The component 10 is realized. By vacuum deposition using SiO as a film forming material
The formed silicon oxide film is made of plastic, particularly PMM.
Excellent adhesion to A. This silicon oxide film is
In addition, the hardness is low, and during film formation by vacuum evaporation,
By introducing oxygen, the membrane becomes porous
It is possible to add elasticity with flexibility according to the amount of oxygen introduced.
Can be given. Moreover, by introducing oxygen during film formation.
As a result, the stress of the silicon oxide film 14 (internal stress of the thin film) is also reduced.
Can be. Accordingly, such a silicon oxide film 14 is provided.
Expansion of the antireflection film 16 during film formation, and
And the large shrinkage of the substrate 12 caused by the cooling after the film formation.
The deformation is absorbed by the elastic silicon oxide film 14 and this
Preventing damage and distortion of the antireflection film 16 due to deformation
I can do things. Moreover, the stress of the silicon oxide film 14 can be reduced.
For this reason, the film itself basically has little distortion. That
Therefore, the antireflection film 16 due to deformation of the substrate 12 during film formation.
To prevent a decrease in adhesion due to damage and distortion of
It has an antireflection film 16 with high adhesion, and has excellent durability.
The optical component 10 can be realized. Here, according to the study by the present inventor, oxidized soot
The effect of improving the adhesion by the base film 14 is that of the silicon oxide film 14.
If the film thickness is too thin, it cannot be fully used.
The thickness of the silicon oxide film 14 is required.
The thicker the film, the better the adhesion. FIG. 2 shows a film forming material on the surface of the substrate 12.
Then, a silicon oxide film using SiO is formed as an adhesion layer.
As shown in FIG. 1, an antireflection film 16 is formed thereon.
In an optical component having a configuration similar to that of
The antireflection film 16 when the film thickness is changed in various ways
This shows the adhesion strength. The antireflection film 16 has a thickness of 20n.
m high refractive index layer 18a, low refractive index layer 20 having a thickness of 30 nm
a, a high refractive index layer 18b having a thickness of 100 nm, and a thickness of 9
It consists of 4 layers of low refractive index folded layer 20b of 0 nm.
The curvature layer 18 is ZrO as a film forming material.₂And TiO₂Mixed with
Low refractive index layer using compound (OP-5 OH-5)
20 is SiO as a film forming material.₂Each using film
Went. For film formation, oxygen is introduced into a normal vacuum evaporation system.
It was carried out by vacuum deposition in an apparatus with additional means. Ma
In addition, the silicon oxide film is deposited in the deposition system (in a vacuum chamber).
8 × 10^-FourAfter exhausting to Pa, oxygen is introduced into the system
By doing so, the pressure in the system is 7 × 10^-2Adjust this to
This was performed as a film forming pressure. The film thickness of the silicon oxide film is
Based on the film deposition simulation performed,
Controlled. In each optical component illustrated in FIG.
Except for the film thickness of the silicon oxide film, it is exactly the same. The evaluation of the adhesion strength of the antireflection film 16 is
In one tape test and one cellophane tape test
Cellophane with adhesive force of 1 to 2 times when film peeling occurs
When film peeling occurs in the loop test, the adhesive strength is 2 or 4 times.
If there is no film peeling even in the Rohan tape test,
Evaluated as adhesion 3 and sample with adhesion 3 and adhesion 2
When the sample of 2 is mixed, the adhesion strength is 2.5 and the adhesion strength is 2.
Adhesion when sample and sample with adhesion 1 are mixed
It was evaluated as 1.5. As shown in FIG. 2, SiO is used as a film forming material.
Film thickness of silicon oxide film (adhesion layer) formed by vacuum evaporation as
The thicker the film is, the higher the adhesion of the antireflection film 16 is.
In this case, when this film thickness is 300 nm or more, the adhesion force
The rating of 3 is the highest. Therefore, the silicon oxide film 14 is provided.
In addition, according to the present invention in which the film thickness is increased,
Optical component with improved durability by improving adhesion of stop film 16
Can be realized. As described above, the optical component of the present invention has a plastic plate.
An antireflection film 16 is formed on a stick substrate 12
In an optical component, between the substrate 12 and the antireflection film 16
Furthermore, the substrate 12 has good adhesion and a thick adhesion layer.
Absorbing effect of substrate deformation by adhesion layer
Has an anti-reflective film 16 with high adhesion and high adhesion
The optical component 10 having excellent durability is realized.
Specifically, acrylic such as PMMA is used as the substrate 12.
Silicon oxide film 14 as an adhesion layer using a base resin material substrate
Is used. Here, in the optical component 10 of the present invention,
There is no particular limitation on the thickness of the silicon oxide film 14 (adhesion layer).
In addition, the use of the optical component 10, required durability and optical characteristics
Thickness that meets the required characteristics
Just set. As described above, the adhesion to the substrate 12 is added.
The substrate 12 changes due to heating / cooling by vacuum deposition.
By absorbing the shape, the antireflection film 16 and the substrate 12
The silicon oxide film 14 that improves the adhesion of the material is suitable for its effect
It is necessary to increase the thickness to some extent in order to develop
There is. In addition, according to the study of the present inventor, it is called adhesion.
Basically, the thicker the silicon oxide film 14 is, the more advantageous it is.
is there. Note that sufficient adhesion of the antireflection film 16 is ensured.
The film thickness required for this is the characteristic of the silicon oxide film 14 (adhesion layer).
Of course, depending on the
The elasticity of the film 14 depends on whether oxygen is introduced during film formation,
Since it varies depending on the amount of element introduced, is it necessary for each?
The preferred film thickness is different. On the other hand, the purpose and purpose of the optical component 10 are as follows.
Depending on the durability, required adhesion of the antireflection film 16
The power is different. For example, in the example shown in FIG.
Depending on the application of the part 10, the adhesion force of the evaluation 3 is unnecessary,
In some cases, a contact strength of 2.5 is sufficient, so be sure
However, in all cases, a film thickness of 300 nm or more is essential.
Not that. Also, in terms of optical characteristics, a silicon oxide film
14 is advantageous to be thinner. Further, the silicon oxide film 14
When the film formation time becomes longer,
That is disadvantageous in terms of productivity, and
The temperature rise of the substrate 12 due to heating increases,
The damage to the substrate 12 is increased. Such a trend
In the multilayer film (multi-coat) as in the present invention, it is remarkable.
The In other words, the optical component 10 of the present invention has an adhesive property and
In this respect, it is advantageous that the silicon oxide film 14 is thicker.
The upper limit of the thickness of the silicon oxide film 14 is the required optical characteristics.
This is inevitably determined by the characteristics and heat resistance of the substrate. That is, in the present invention, thick silicon oxide
The film 14 (adhesion layer) is an optical component required for the optical component 10.
Characteristics, damage to the substrate 12 during film formation, productivity, etc.
Taking into account the thickness within the range where the desired adhesion can be achieved
A silicon oxide film 14 having a thickness, the material of the substrate 12;
Forming material and configuration of antireflection film 16, for optical component 10
Depending on the required durability and optical characteristics, etc.
What is necessary is just to determine suitably. An example is shown in FIG.
In the example of the optical component 10, the thickness of the silicon oxide film 14
Is preferably 100 nm to 800 nm, particularly 300 nm.
nm to 600 nm are preferable. In the optical component 10 of the present invention, such
On the silicon oxide film 14 acting as a good adhesion layer,
Layer) An antireflection film 16 is formed. In the example shown,
The anti-reflection film 16 includes a high refractive index layer 18 made of a high refractive index material.
And a low refractive index layer 20 made of a low refractive index material, alternately
It has a four-layer structure in which two layers are stacked. In the present invention, the antireflection film 16 is used.
The high refractive index layer 18 and the low refractive index layer are not limited to this.
20 and alternately forming at least one layer,
Various known multi-layer anti-reflection coatings can be used
Noh. Therefore, the layer structure is not particularly limited,
For example, the high refractive index layer 18 and the low refractive index layer 20 are formed one by one.
It may be an antireflective film, and it has a high bending resistance of 3 layers or more.
Even an antireflection film having the refractive index layer 18 and the low refractive index layer 20.
Good. Also, the high refractive index layer 18 and the low refractive index layer 2
There is no limitation on the forming material of 0, and various multilayer antireflection films
Anything that is used in the can be used. For example, high
As the refractive index layer 18, ZrO₂A layer having a film-forming material as
TiO₂A layer having a film-forming material as Z, such as OH-5
rO₂And TiO₂A layer having a mixed material of Y as a film forming material, Y ₂
O_ThreeA layer using CeO as a film forming material, CeO₂As a film-forming material
Layer, Ta₂O_FiveAnd the like, and the like.
The low refractive index layer 20 is made of SiO.₂The film forming material and
Layer, MgF₂A layer using CaF as a film-forming material, CaF₂Film formation
Examples of such layers include materials. Similarly, the antireflection film
There is no particular limitation on the thickness of each layer to be formed.
Decide as appropriate according to configuration, required optical characteristics, etc.
That's fine. In such an optical component 10 of the present invention,
The silicon oxide film 14 and the antireflection film 16 are
What is necessary is just to perform by well-known methods, such as air evaporation. Also, as mentioned above
Further, as a preferred embodiment, the silicon oxide film 14 is made porous.
Vacuum evaporation while introducing oxygen.
Yes. In addition, even when resistance heating is used for film formation, an electron beam is used.
Although heating may be used, the film formation of the silicon oxide film 14 is
Uses anti-heating and slowly at a relatively low film formation rate
It is preferred to do so. The heating energy is 400A or higher.
It is preferable to use the following. As a result, the silicon oxide film 14
Can be imparted with elasticity having more suitable flexibility.
Furthermore, in the formation of a relatively thick silicon oxide film 14
The temperature rise of the substrate can also be reduced. By the way, in film formation by vacuum deposition, film formation is performed.
Due to the characteristics of the material, the deposition material bumps during deposition.
So-called splash may occur.
As a result, deterioration of the film properties, etc. occur and the yield decreases.
The In order to prevent such inconvenience, film formation that is easy to bump
When using materials, the process in the hearth must be performed prior to film formation.
The film material is melted once, so-called melting is performed.
The In particular, the film forming material of the high refractive index layer 18 is not melted.
Often necessary. Usually, melting is performed prior to film formation.
However, according to the study by the present inventors, the film forming material
If it melts, the material will adhere to the substrate 12.
This is a decrease in adhesion of the adhesion layer, that is, the silicon oxide film 14
It is one of the causes. Therefore, the optical component 10 of the present invention is
In manufacturing, after forming the silicon oxide film 14, the film is formed.
It is preferable to melt the material. The optical component of the present invention has been described in detail above.
As described above, the present invention is not limited to the above-described examples.
Various improvements and changes have been made without departing from the spirit of the invention.
Of course, you may. [0033] EXAMPLES Specific examples of the present invention will be given below.
Will be described in more detail. [Embodiment] As schematically shown in FIG.
Further, a commercially available vacuum deposition apparatus 50 (hereinafter referred to as a deposition apparatus).
50) using an apparatus to which oxygen introducing means is added,
The optical component 10 shown in FIG. 1 was created. This steam
The deposition apparatus 50 uses an electron beam as a heating means for the evaporation material.
An electron gun evaporation source 28 for heating by resistance, and resistance heating
And a resistance heating evaporation source 30 for heating. First, the vapor deposition apparatus 50 (vacuum chamber 22).
The inner rotating dome 24 has PMMA (Mitsubishi Rayon Co., Ltd.,
A lens made of VH001) was set as the substrate 12.
The rotating dome 24 is fixed by the rotating means 26.
It is rotated at a constant speed. Next, a film forming material for the silicon oxide film 14
As a material, SiO is a predetermined position of the resistance heating evaporation source 30 (ha
Set). Further, a film forming material for the high refractive index layer 18
OH-5 (ZrO₂And TiO₂Mixture of op
(Made by TRON) as a film forming material for the low refractive index layer 20
O₂, Respectively, at predetermined positions of the electron gun evaporation source 28 (H
Set. Vacuum chamber 22 (hereinafter referred to as chamber 22)
Evacuate, and then evacuate the pressure in the chamber 22
Power 8 × 10^-FourWhen Pa is reached, oxygen enters the chamber.
To adjust the pressure to 0.05 Pa, and then
The resistance heating hand of the resistance heating evaporation source 30 is opened.
Drive the stage to heat the hearth filled with SiO.
Silicon oxide film with a thickness of about 400 nm at a deposition pressure of 05 Pa
14 was deposited. The resistance in the resistance heating evaporation source 30 is
The anti-heating means has a 6 kW resistance heating electrode.
Then, 350A power is supplied to heat resistance of SiO.
Then, film formation was performed. After the silicon oxide film 14 is formed, the shutter 32 is
Occluded and the pressure in the chamber 22 is 1 × 10^-3With Pa
At that time, in the electron gun evaporation source 28, 250 mA
Drive the electron gun with output to the hearth that houses OH-5
Irradiate and scan with electron beam to dissolve OH-5
I rubbed in. After the melting is finished,
The pressure in the chamber 22 that has been raised is 1 × 10^-3With Pa
At that time, the shutter 32 is opened and the electron gun evaporation source 28 is opened.
In the hearth, OH−
5 is irradiated with an electron beam to form a thickness on the silicon oxide film 14.
A high refractive index layer 18a having a thickness of about 20 nm was formed. In addition,
The membrane pressure is 8 × 10^-3Pa. After the film formation of the high refractive index layer 18, the film formation is increased.
The pressure in the chamber 22 is 1 × 10^-3When it becomes Pa
At that point, the electron gun evaporation source 28 switches Haas,
SiO in the hearth with an electron gun output of 85 mA₂To electronic bee
About 30 n thick on the high refractive index layer 18a.
An m low refractive index layer 20a was formed. The film formation pressure is
1 × 10^-3Pa. After the film formation of the low refractive index layer 20a is completed, the film formation is completed.
Increased pressure in chamber 22 is 1 × 10^-3Pa
At this point, Haas is switched in the electron gun evaporation source 28.
The power of the electron gun is 230 mA, and the OH-5 in the hearth is
A child beam is irradiated to form a thickness of about on the low refractive index layer 20a.
A 100 nm high refractive index layer 18b was formed. Film formation
Pressure is 8x10^-3Pa. After the film formation of the high refractive index layer 20, the film formation is performed.
The pressure in the chamber 22 that has been raised is 1 × 10^-3With Pa
At that point, in the electron gun evaporation source 28, Haas is turned off.
In exchange, SiO in the hearth with the output of the electron gun of 85 mA₂To
Irradiate the child beam, on the high refractive index layer 18b, the thickness is about
A 90 nm low refractive index layer 20b is formed, and the antireflection film 16 is formed.
An optical component 10 of the present invention having the following was produced. Low bending
The film forming pressure of the refractive index layer 20b is 1 × 10 5 as before.^-3P
a. Antireflection film from the start of film formation of silicon oxide film 14
16 (low refractive index layer 20b) until the film formation is completed.
The temperature ranged from room temperature to 80 ° C. Introduce oxygen
This is only performed when the silicon oxide film 14 is formed. Each film thickness
The design value by optical simulation software
Used to obtain desired optical characteristics
It is. In addition, the film thickness of each film (layer)
The film formation time was controlled based on the simulation. [Comparative Example] The film thickness of the silicon oxide film 14 is 50 n.
Except for m, the same as in Example 1, the optical
Parts were produced. The optical component of the example obtained in this way
10 and the optical component of the comparative example, antireflection film
16 adhesions were examined. The optical characteristics are both
Both were sufficient. The adhesion test was performed on one
30 randomly selected from 600 (600) optical components
The cellophane tape (Nichiban No. No.
405) is affixed strongly, and the tape is perpendicular to the film surface.
Visual confirmation of film peeling when peeled off instantaneously
I went there. No film peeling was observed in all optical parts.
O
△ sample that generated even one product, almost completely peeling
A sample with any single optical component generated was evaluated as x
It was. Even after repeating the same test 10 times, all
Samples with no delamination in optical parts
In particular, it was evaluated as ◎. As a result, the optical component 10 of the present invention.
The evaluation was ◎, and the evaluation of the optical component of the comparative example was ×. Shi
Moreover, in the optical part of the comparative example, all 30 samples
In this case, the entire film peeled off. From the above results, the present invention
The effect is obvious. [0045] As described above in detail, the present invention is applied.
According to this, the high refractive index layer and the low refractive index layer are alternately formed on the substrate.
In an optical component having a multilayer antireflection film formed
Therefore, the adhesion of the multilayer anti-reflection film is high, so it is durable.
Excellent optical components can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual diagram of an example of an optical component of the present invention. FIG. 2 is a graph for explaining an optical component of the present invention. FIG. 3 is a conceptual diagram of an example of a vacuum deposition apparatus. DESCRIPTION OF SYMBOLS 10 Optical component 12 Substrate 14 Silicon oxide film 16 (Multilayer) Antireflection film 18 High refractive index layer 20 Low refractive index layer 22 (Vacuum) Chamber 24 Rotating dome 26 Rotating means 28 Electron gun evaporation source 30 Resistance heating Evaporation source 32 Shutter 50 Vacuum evaporation system

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Claims (1)

What is claimed is: 1. A substrate made of an acrylic resin material; a thick silicon oxide film formed on a surface of the substrate; and a low refractive index formed on the silicon oxide film. An optical component comprising: a multilayer antireflection film formed by alternately forming at least one layer made of a refractive index material and a layer made of a high refractive index material.