JPS63220102A - Anti-reflection coating for plastic optical components - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an antireflection coating for plastic optical components used in optical systems such as projection televisions, video cameras, and still cameras.

Conventional technology Traditionally, inorganic glass has been widely used for optical components such as lenses, but in recent years, plastics have been used as materials for optical components because they are lightweight, easy to process, and suitable for mass production. It has come to be used. However, plastic optical components such as plastic lenses have the same drawback as inorganic glass in that they reflect a large amount of light on their surfaces. In order to overcome this drawback, it is well known as a general technique to prevent surface reflection by forming an antireflection film on the surface of plastic optical components, similar to the antireflection film formed on the surface of inorganic glass. There is. (
For example, [Design of precision plastic optical lenses, molding technology and their problems] Trikebus technical data collection N1187P6
-1 to P6-4) The conventional antireflection coating for plastic optical components will be explained below with reference to the drawings. Second
The figure shows the surface of a plastic optical component! ! # This is a diagram showing a structure in which an anti-reflection film made of magnesium fluoride similar to the anti-reflection film formed on the surface of machine glass is formed, and Figure 3 (b) is a diagram showing spectral reflection characteristics, and a diagram for comparison. Third
Figure (C) shows an anti-reflection film In Figure 2, 1 is a plastic optical component and 5 is an anti-reflection film made of magnesium fluoride. The antireflection film 5 is generally formed by a vacuum deposition method, but recently, plastic optical components are heated to 60°C to 80°C in order to improve the adhesion and durability between the antireflection film and the plastic optical components. A method of forming an antireflection film using a heating method or an RF bioion blating method has been used.

Problems to be Solved by the Invention However, in the above-mentioned conventional example in which an antireflection film made of magnesium fluoride is formed by vacuum evaporation, the flow temperature and heat distortion temperature of the plastic are low, and the release from the inside of the plastic is low. Due to gas issues,
A strong vapor deposited film cannot be formed by heating the substrate (usually at 300° C. to 400° C.) as in the case of forming a vapor deposited film on an inorganic glass substrate. For this reason, anti-reflection films have been formed on the surfaces of plastic optical components at low temperatures of 50 to 60 degrees Celsius or lower, but anti-reflection films formed at these low temperatures have poor adhesion to plastic surfaces and are not durable. It is low.

In addition, as mentioned above, plastic optical parts can be heated at 60°C
When an anti-reflective film is formed by heating it to 80°C or using the RF bio-ion blating method, cracks tend to occur in the anti-reflective film, and it is necessary to keep the conditions at the time of formation constant and the state of the plastic surface constant. It is also difficult to maintain the temperature and is not suitable for mass production. Furthermore, Figure 3 (bl
As shown in the figure, the anti-reflection coating made of a single layer of magnesium fluoride has a residual reflectance of about 1.0 at the center wavelength (λ).
5%, which does not have sufficient properties as an antireflection film for plastic optical parts.

As mentioned above, conventional antireflection coatings for plastic optical components have had the problems of poor adhesion to the plastic surface, poor durability, and insufficient optical properties as an antireflection coating. .

In view of the above-mentioned problems, the present invention provides an antireflection film with excellent adhesion, durability, and optical properties for plastic optical components.

Means for Solving the Problems In order to solve the above problems, the present invention provides a first layer on the surface of a plastic optical component in order from the surface side to the air side.
The anti-reflection film is constructed by forming a vapor deposited film with a three-layer structure of a second layer and a third layer, the first layer being a mixture of silicon monoxide and zirconium oxide, the second layer being a mixture of zirconium oxide,
The third layer provides an antireflection film characterized by being made of silicon dioxide.

Function The present invention provides a method of applying a mixture of silicon oxide and zirconium oxide, zirconium oxide,
A three-layer antireflection film made of silicon dioxide is formed, and as a result, an antireflection film with excellent adhesion, durability, and optical properties can be obtained.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the structure of the antireflection film of the plastic optical component of the present invention, and FIG. 3(a) shows its spectral reflection characteristics. In FIG. a first layer consisting of a mixture of 3. 4 is the second layer made of zirconium oxide, and 4 is the third layer made of silicon dioxide.
The specific contents in the examples of the present invention are as shown in Table 1.

Table 1 ■ Eyes (λ. = 550 dragons) In addition, each layer is made of plastic optical components heated at 60°C.
It was formed by a vacuum evaporation method under the following conditions. The first layer was formed by simultaneously evaporating silicon monoxide and zirconium oxide from separate evaporation sources.

A test was conducted to compare the adhesion and durability of the anti-reflective film of the example of the present invention and a conventional anti-reflective film.
11 Sellotape peel test (temperature 40℃, relative humidity 85%)
(2) Humidity test (1000 hours in a high-temperature atmosphere with a temperature of 40°C and relative humidity of 95%). 31 Thermal shock test (standing in low and high temperature atmospheres of -30°C, 70°C for about 100 hours, alternately for 30 minutes each), and the conventional anti-reflection film for comparison was Conventional example 1
An anti-reflection coating of magnesium fluoride is applied to the surface of a plastic optical component by vacuum evaporation to an optical thickness of λ. /4 (λ.=550 nm), and has the structure shown in FIG. The results of the adhesion and durability tests are shown in Table 2.

As can be seen from Table 2, the antireflection film of the present invention is superior to conventional antireflection films in terms of adhesion and durability. In addition, the spectral reflection characteristics are approximately 0.22% at the center wavelength (λo = 550 nm), as seen in Fig. 3fa), and are superior to conventional examples as an antireflection film. Furthermore, in the conventional example, cracks sometimes occurred during formation of the antireflection film, but in the examples of the present invention, the antireflection film was always stable.

In the above embodiment, each film thickness was set as shown in Table 1, but the film thickness is not particularly limited to the above values, and may be changed according to the design wavelength, and the film thickness may be changed according to the design wavelength. is the first
Anything is fine as long as it looks like the one shown in the diagram.

Effects of the Invention As is clear from the above explanation, the antireflection coating of the plastic optical component of the present invention comprises: - a first layer made of a mixture of silicon oxide and zirconium oxide, a second layer made of zirconium oxide, and a second layer made of silicon dioxide. By adopting a three-layer structure called the third layer, it increases the adhesion with plastic optical parts and improves the durability of the anti-reflection film, and also has excellent spectral reflection characteristics and prevents the occurrence of cranks. This has the effect of eliminating the drawbacks of the conventional example. Furthermore, the antireflection coating for plastic optical components of the present invention is suitable for mass production, and therefore has great practical value.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an anti-reflection film for a plastic optical component of the present invention, FIG. 2 is a block diagram of a conventional anti-reflection film for a plastic optical component, and FIG. 3 is a spectral reflection characteristic diagram. fa)...Anti-reflection coating for plastic optical components in the embodiment of the present invention, Tb)...Conventional anti-reflection coating for plastic optical components (single-layer film made of magnesium fluoride) ), (C)...Plastic optical component not formed with an antireflection film, 1...
...Plastic optical component, 2...-Thin film made of a mixture of silicon oxide and zirconium oxide, 3.
...Thin film made of zirconium oxide, 4...
...Thin film made of silicon dioxide, 5...Thin film made of magnesium fluoride. Name of agent: Patent attorney Toshio Nakatashi 1 person --- Glass 5 links 4 punnies 1 Tukichi%% 2 --- W & K and spirit hat 7 mi] Nik 44 --- 2 several Kei Figure 1, Figure 2, Figure 3 is all over the place.

Claims (1)

[Claims] A structure in which an antireflection film is formed by forming a three-layer vapor deposited film of a first layer, a second layer, and a third layer on the surface of a plastic optical component in order from the surface side to the air side, An antireflection coating for a plastic optical component, wherein the first layer is made of a mixture of silicon monoxide and zirconium oxide, the second layer is made of zirconium oxide, and the third layer is made of silicon dioxide.