JPH04116502A - Conductive antireflection coat - Google Patents

Abstract

PURPOSE:To obtain the high antireflection effect stable to incident light of 400 to 850nm by forming the 2nd layer of an intermediate layer between a 1st layer and a 3rd layer of a layer which consists of a metal oxide having >=1.5 and <1.9 refractive index and has a specific film thickness. CONSTITUTION:The conductive antireflection coat is set at lambda0 design wavelength existing within the 400 to 850nm range and consists essentially of either of indium oxide and tin oxide or a mixture composed thereof or a mixture composed of the tin oxide and antimony oxide on the surface of optical part. The 1st layer 1 with which the optical film thickness defined by the product of the refractive index and the film thickness is within a (0.032+ or -0.010)lambda0 is formed. The 2nd layer 2 which consists essentially of the metal oxide having >=1.5 and <1.9 refractive index and has the optical film thickness within a (0.204+ or -0.061)lambda0 range is then formed. The 3rd layer 3 which consists of silicon oxide and has the optical film thickness within a (0.255+ or -0.077)lambda0 is formed. The high antireflection effect stable to the incident light of lambda0 wavelength is obtd. in this way.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a conductive antireflection coating formed on the surface of an optical component, and relates to a lens used in a laser printer, a facsimile, a recording/reproducing device for an optical disk or a magneto-optical disk, etc. , relates to a conductive antireflection coating that is particularly suitably used for optical components such as mirror prisms or photoelectric conversion elements.

[Conventional technology]

Conventionally, the first layer on the optical component has a design incident light wavelength of λ. The optical film thickness λ is expressed as the product of the refractive index and the layer thickness. The anti-reflection coating consists of two layers: an indium oxide (+n2oz) layer of 400 nm to 700 nm, and a second layer on top of which is a magnesium fluoride (MgFz) layer with a similar optical thickness.
wavelength λ in the range of . It is known from Japanese Utility Model Publication No. 49-12614 as a conductive anti-reflection coating that reduces the adhesion of dust and toner (hereinafter simply referred to as dust) due to reflection of incident light and charging. Optical film thickness λ. /4 aluminum oxide (Au, O,) or cerium fluoride (CeFa) layer, the second layer thereon is a silicon oxide (Sin2 to 5 inch) layer with an appropriate optical thickness, and the third layer thereon is Optical film thickness λ. /2 indium or indium oxide layer, the fourth layer above it is a silicon oxide layer similar to the second layer, and the fifth layer above it has an optical thickness λ. /4
An antireflection coating consisting of five magnesium fluoride layers is known from Japanese Patent Publication No. 53-28214 as a conductive antireflection coating having similar effects.

However, the conductive antireflection coating described in Japanese Utility Model Publication No. 12614/1983 is applicable only when the surface portion of the optical component on which it is applied, that is, the base, is made of a polymeric material such as acrylic resin, polycarbonate resin, or polystyrene resin. In this case, since the heat resistance of the substrate is low, the substrate temperature must be kept below 20,000 when depositing the first and second layers.
There are problems in that the layer is difficult to form and the moisture resistance of the conductive anti-reflective coating is low. In addition, special public service 53-
In addition to the above-mentioned problems, the conductive anti-reflection coating described in Publication No. 28214 has problems such as low productivity due to the large number of constituent layers, and the production of absorption components when the third layer is an indium layer. Another problem is that the optical properties are inferior to light of the component wavelengths.

In addition, the design wavelength λ. means the wavelength at which the reflectance of the antireflection coating is minimized. Further, hereinafter, the optical film thickness is also simply referred to as film thickness.

[Problem to be solved by the invention]

The present invention was made in order to solve the above-mentioned problems with conductive anti-reflection coatings, and the number of layers constituting the conductive anti-reflection coatings is small, productivity is high, and the substrate of optical components is The design wavelength λ is any wavelength in the range of at least 400 to 850 nm that has excellent moisture resistance, is difficult to peel off, and does not generate absorption components even if it is made of a polymeric substance. can be set to λ0
An object of the present invention is to provide a conductive antireflection coating that stably provides high transparency, that is, antireflection effect, to incident light having a wavelength of , and effectively prevents the adhesion of dust due to charging.

[Means to solve the problem]

The present invention provides a conductive anti-reflection coat formed on the surface of an optical component, in which the conductive anti-reflection coat has an anti-reflection coating of 400 to 80%.
Defined as the product of refractive index and layer thickness, with the design wavelength in the range of 50 nm being λ0, on the surface of an optical component whose main component is either one or a mixture of indium oxide and tin oxide, or a mixture of tin oxide and antimony oxide. The main components are a first layer whose optical thickness is in the range of (0,032±0.Q10)λ0, and a metal oxide on top of which the refractive index is 1.5 or more and less than 1.9. The optical film thickness is C0,204±0
．． 061)λ. The optical thickness is (0,255±0
．． 077) λ. The above object is achieved by this construction of a conductive anti-reflection coating characterized in that it consists of three layers with a third layer in the range of .

[Effect]

In other words, the conductive antireflection coating of the present invention has a three-layer structure, so productivity is high, and the third surface layer of the three-layer structure has a refractive index of about 1.49. The silicon oxide layer has a specific thickness and can be easily deposited to form a moisture-resistant and hard-to-peel film even when the substrate temperature is low, reducing surface reflections and making the substrate of optical components more stable. Even if it is made of a polymeric material, it has excellent moisture resistance and is difficult to peel off. The second layer of the intermediate layer between the first layer and the third layer has a refractive index of 1.5. As mentioned above, since the metal oxide layer has a specific thickness of less than 1.9, there is no deterioration of optical properties due to the generation of absorption components, and if the third surface layer is a single layer, the thickness is about IQ + 20/mouth. Even though it is made of silicon oxide, which provides high surface electrical resistance, it prevents dust from adhering to it due to charging, and exhibits excellent overall translucency.

〔Example〕

Hereinafter, the present invention will be explained by examples.

FIG. 1 is a schematic cross-sectional view showing a state in which the conductive antireflection coating of the present invention is formed on the substrate of an optical component, and 0 is an acrylic resin, a polycarbonate resin, a polystyrene resin, a polysulfone resin, The transparent substrate on the surface of the optical component is made of a polymeric substance such as an amorphous polyolefin resin or an inorganic substance such as a glass material, and l is λ. 400～
When the conductive anti-reflection coating is set to a value in the range of 850 nm, the film thickness of the conductive anti-reflection coating mainly composed of one or a mixture of indium oxide and tin oxide or a mixture of tin oxide and antimony oxide is (0,032± 0.010)λ.

The first layer 2 has a refractive index N in the range of 1.5≦N<1.
9, preferably cerium oxide, aluminum oxide, or a mixture of aluminum oxide and zirconium oxide, the film thickness is (0.204 mm 0.061 mm).
λ. The second layer 3 is mainly composed of silicon oxide and has a thickness of (0,255±0.077)λ. This is the third layer.

The first layer 1 preferably consists of pellets of a mixture of indium oxide and tin oxide with a tin content of 5 to 10% by weight, or a mixture of tin oxide and antimony oxide with an antimony content of 5 to 10% by weight, or indium oxide or tin oxide. As a vapor deposition material, the temperature of the substrate 0 is maintained at an appropriate temperature in the range of 20 to 300 ° C. depending on the material by a reactive vapor deposition method using electron gun heating.
Oxygen atmosphere with oxygen pressure 1~4X 10-'Torr, 5~
Under the condition of a deposition rate of 30 people/sec, or by the ionization deposition method using electron gun heating (for example, Japanese Patent Publication No. 56-40447
1), the substrate temperature is maintained at the same temperature as above, and the oxygen pressure is 1 to 5 while discharging from a high frequency discharge antenna at 13.56 MHz with an output of 300 W, for example.
X 10-'Torr oxygen atmosphere, 5-40 people/se
It can be formed by depositing a deposition material on the substrate 0 at a deposition rate of c. The second M uses a metal oxide with N of 1.5≦N<1.9, such as cerium oxide, aluminum oxide, or a mixture of aluminum oxide and zirconium oxide, as a deposition material, and uses an ionization deposition method using electron gun heating to increase the deposition rate. The deposition material can be deposited on the first layer 1 under the same conditions as for forming the first layer, except that the rate is 10 to 40 people/sec. The third layer is preferably SiO□ or SiO
The evaporation material is formed by evaporating the evaporation material on the second layer 2 under the same conditions as for forming the second layer, except that the evaporation rate is 10 to 50 people/see, using a mixture of silicon oxide particles or pellets as the evaporation material. can.

The antireflection coating of the present invention formed on the substrate 0 as described above has a stable λ in the range of 400 to 850 nm.

has low reflectance to incident light and excellent translucency, and the surface electrical resistance of the third layer 3 is approximately 10100/mouth to prevent dust adhesion due to charging.
It also has excellent environmental resistance, as no film peeling or deterioration of optical properties was observed even after it was left in an environment for one week. This point will be further explained in the following examples and comparative examples.

Example 1 A transparent acrylic resin plate was used as the substrate, and the antimony content was 5.
Using pellets of a mixture of tin oxide and antimony oxide (wt%) as a vapor deposition material, the temperature of the substrate O was 15 to 40°C, and the discharge power of the high-frequency discharge antenna was 30°C, using the above-mentioned ionization vapor deposition method.
0W, frequency 13.56MHz, vapor deposition atmosphere oxygen pressure 2
A film thickness of 20 nm (0,032λ.; However,
Design wavelength λ. was set at 632 nm), and then using cerium oxide pellets as the evaporation material, the discharge power of the high frequency discharge antenna was 200 W, and the evaporation rate was set to 15 people/
A second layer 2 with a film thickness of 129 nm (0,204λ) was formed on the first layer l under the same conditions as the first layer except that sec was used, and then silicon oxide (S10□) granules were evaporated. As a material, the vapor deposition atmosphere oxygen pressure I x 10-'Torr
, a film thickness of 161 nm (0,255
A third layer 3 of λ0) was formed. The optical component thus obtained has a spectral reflectance of incident light at wavelength λ. So 0.
2% or less (as shown in curve l of the spectral reflectance graph in Figure 2)
It has excellent translucency. In addition, the surface electrical resistance of the third layer 3 was less than 10''Ω, and the effect of preventing dust adhesion due to charging was sufficient.
No peeling of the film was observed even after leaving it in the H environment for one week. All surface electrical resistances are values measured using a surface electrical resistance measuring device 5M-10E manufactured by Toa Denki under the condition of applying a voltage of 100 OV between the center electrode and the surrounding electrodes.

Example 2 Conditions for forming the ill were: pellets of a mixture of indium oxide and tin oxide with a tin content of 5% by weight were used as the evaporation material, the evaporation atmosphere was oxygen pressure 3 x 10-' Torr, and the evaporation rate was 8%/sec. Other than that, it is exactly the same as Example 1,
First layer 1-third layer 3 were formed. The obtained optical component also showed the same spectral reflectance as Example 1, the surface electrical resistance of the third layer 3 was 10'Ω/or less, the effect of preventing dust adhesion due to charging was sufficient, and the environmental resistance was improved. It was also the same as that of Example 1.

Example 3 The second layer 2 was formed using aluminum oxide as the vapor deposition material, and the discharge power of the high frequency discharge antenna was 250W.

Deposition atmosphere oxygen pressure 2.5X 10 Torr, deposition rate 10 people/sec, film thickness 1100n ('0.16λ0)
The first layer 1 to the third layer 3 were formed in exactly the same manner as in Example 1, except that the second layer was different from Example 1 in that the second layer was the same as that in Example 1. The obtained optical component had a spectral reflectance of λ as shown by curve 2 in FIG. It had excellent light transmittance with a reflectance of about 1%, and the effect of preventing dust from accumulating due to electrostatic charge and environmental resistance were also as good as those of Example 1.

Example 4 The second layer was formed using a mixture of aluminum oxide and zirconium oxide in a weight ratio of 1:1 as the deposition material, and the discharge power of the high frequency discharge antenna was 250 W.

Vapor deposition atmosphere oxygen pressure 2.5X 10''' Torr, vapor deposition rate 10 people/sec, film thickness 120 nm (0.19λ.)
and the formation conditions for the third layer 3 were a film thickness of 156 nm.
The first layer 1 to the third layer 3 were formed in exactly the same manner as in Example 2, except that it was different from Example 2 in that (0,25λ.). The obtained optical component has excellent light transmittance with a spectral reflectance of 0.5% at λ0 as shown by curve 3 in Fig. 2, and is effective in preventing dust adhesion due to charging and environmental resistance. The properties were also as good as in Example 1.

Comparative Example When forming each layer 1 to 3 in each of the above-mentioned Examples, the thickness of one of the layers was increased or decreased from the thickness of Example 1, and the resulting optical component showed a rate of increase in thickness. Or, if the reduction rate is within 30%, the design wavelength λ.

The reflectance was 5% or less, which was a value that could be used, but when it exceeded that value, the reflectance exceeded 5% and became unusable.

〔Effect of the invention〕

The conductive anti-reflection coating of the present invention has a small number of constituent layers and high productivity, and even when the transparent substrate of an optical component is made of a polymer material, it has excellent moisture resistance, is difficult to peel off, and absorbs At least 40% without any components
The design wavelength λ is any wavelength in the range of 0 to 850 nm.

can be set to λ. It provides stable high transparency, that is, anti-reflection effect, to incident light with a wavelength of , and effectively prevents dust adhesion due to charging.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing the state in which the conductive anti-reflection coating of the present invention is formed on the substrate of an optical component, and FIG. 2 is a spectral diagram showing an example of the spectral reflectance of the conductive anti-reflection coating of the present invention. It is a reflectance graph. 0...Transparent substrate l...First layer 2...Second
Layer 3...Third layer Figure 1

Claims (2)

[Claims] (1) In the conductive anti-reflection coat formed on the surface of the optical component, the conductive anti-reflection coat has a molecular weight of 400 to 850
Defined as the product of refractive index and layer thickness on the surface of an optical component whose main component is either one or a mixture of indium oxide and tin oxide, or a mixture of tin oxide and antimony oxide, with the design wavelength in the nm range being λ_0 The optical film thickness is (
0.032±0.010) The optical film thickness is ( 0.204±0
．． 061) The second layer is in the range of λ_0 and the optical film thickness is (0.255±
0.077) A conductive anti-reflection coating comprising three layers with a third layer in the range of λ_0. (2) The conductive antireflection coat according to claim 1, wherein the metal oxide of the second layer is cerium oxide, aluminum oxide, or a mixture of aluminum oxide and zirconium oxide.