JPS60154201A - Plastic optical parts - Google Patents

Abstract

PURPOSE:To obtain optical parts having high transmittance and superior heat resistance and undergoing no change in the characteristics with the lapse of time by directly forming an SiO2 film on the surface of plastics and forming other antireflection films on the SiO2 film in order. CONSTITUTION:An SiO2 film 3 of 50nm-0.5mum thickness is directly formed on the surface of plastic optical parts such as an acrylic resin or polycarbonate lens 4, and an Al2O3 film 2 and an MgF2 film 1 are successively laminated on the film 3 to form a multilayered antireflection film. An SiO2 film 10, a ZrO2 film 9 and an MgF2 film 8 may be successively formed on the surface of a plastic lens 11. Since the thickness of the films 3, 10 is adjusted to said range, the adhesive strength to the multilayered antireflection films and the lenses 4, 11 is increased, and damper action by which stress of thermal expansion is absorbed is provided to the films 3, 10 to prevent cracking. Thus, plastic optical parts having high transmittance and superior durability is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to optical components made of Plasti-9, such as Plasti-9 lenses.

[Background of the invention]

For example, Plasti-9 Cleanse is known as an optical component made of Plasti. Hereinafter, Plasti-9 Cleanse will be explained as an example.

An important issue for plastic lenses is the use of anti-reflection coatings to increase transmission. Ten thousand,
Although plastic lenses have advantages over glass lenses, such as being lighter and easier to mass produce, they also have disadvantages, such as the fact that a single layer of anti-reflection coating is insufficient because the refractive index is generally low.

Therefore, it is necessary to improve the transmission by using a multilayer antireflection coating (hereinafter referred to as V multi-layer coating). However, it is not easy to apply multi-coating to Plasti-9 Cleanse. For example, first, a thermosetting resin T, which has good adhesion to plastic, is applied to the surface of Plasti-9 Cleanse.
- After coating and curing, there is a risk that the surface precision of the plastic lens will be affected due to the difficulty of marking the edges.

Now, among plastic lenses, acrylic lenses have attracted attention because they have excellent transparency, good injection bottom shape, and are suitable for mass production, and attempts have been made to apply multi-coating to acrylic lenses. ing. However, the adhesion between acrylic and inorganic coach ink film is very poor compared to other plastics, making multi-coating of acrylic lenses very difficult. For example, the CR-39 (product name) lens used for mechanical lenses is 8102&'r
1,4.
.

Methods such as a thermal cicada layer and a fat-spread dense layer were used, which caused the above-mentioned deficiencies.

-10,000, %-11@F+6-11ri9Q1 publication,
From the air side to the plastic side of the Plasti 9 cleanse,
Layer II-Mf! A configuration with W'2 and second JiltAJhOs has been proposed, but this configuration is suitable for acrylic lenses.

When used, adhesion is good at room temperature (20℃) and no cracking occurs, but when exposed to a high temperature test of 80℃ for 12 hours, cracking occurs and the amount of permeable straw is significantly reduced. I found out that it does. Therefore, the present inventors have already developed a multi-coating structure with excellent transmission S characteristics, adhesion, and durability by adding a first layer fMgF2 and a second layer with a refractive index of 1.55 or more on the plastic side from the air side. We proposed a configuration using SiO. This is to ensure good transmission properties over a long period of time by grasping the aging of 810 and increasing the refractive power of the initial SiO.
otl - Use is undesirable and further improvements are desired.

By the way, with the shift to plastic lenses, plastic lenses have come to be used for silk lenses for cameras, etc. However, when using plastic lenses for such lens sets, 1vc*yr is used due to achromatization. ;s＊＋＊v
y−xhaw*w, *+wxvyt.

219i! 6 lenses are used in combination, and examples of low refractive index and low dispersion lenses include Acrylic and 4
Examples of high refractive index and high dispersion lenses include 1. Polycarbonate lenses are used.・ In this case, it is necessary to provide an anti-reflection coating on the polycarbonate lens as well as the acrylic lens mentioned above.
This polycarbonate lens has the aforementioned CP-39.
Assuming that the anti-reflection effect of %5102 is 9 as with the lens, in the case of the CP-39 lens, its refractive index is 1.51, which is rounded relatively close to the refractive index of 5102 (1,45). , 5102! Even if m is increased, the pull that occurs in the spectral transmission characteristics is small and hardly a problem, but in the case of polycarbonate lenses, the refractive index of the line is 1.58, which is larger than that of 8102
For this reason, when 8102 is made thicker, the spectral transmission characteristics have the disadvantage that a large pull occurs and is significantly degraded. When the thickness of the 8102 layer on the polycarbonate lens was Q54m or more, when a heat resistance test was conducted at 80C for 12 hours, the polycarbonate lens was subjected to a heat resistance test, and the spectral transmission peak was significantly reduced. Home appliances such as video cameras are exposed to high temperatures of 80C for long periods of time.
The use of polycarbonate lenses with anti-reflection coatings in video camera lens systems poses problems, as practical performance must be maintained even under such conditions.

A method has also been proposed in which a thermosetting resin having a refractive index close to that of bent straw is coated on the surface of polycarbonate and then cured, and then a multi-coating is applied thereon.
It is difficult to maintain a constant film thickness of the thermosetting resin, and the disadvantage is that the precision of the lens surface deteriorates.

Furthermore, the surface of a high refractive index, high dispersion lens such as polycarbonate has a refractive index close to that of the refractive index of this lens.
io (refractive index = 1.60), and Z
roz layer and further u@'l' layer, 5idl
e, Zr02j* and Ml! According to this antireflection film, which was proposed to have a 3-antireflection effect consisting of an F2 layer, the antireflection effect was good, and no flashing/-v warping occurred in a heat resistance test at 80°C.

However, the refractive power of SiO changes significantly over time, and polycarbonate lenses coated with such an antireflection film have the disadvantage that it is difficult to maintain their initial refractive power characteristics. [Purpose of the present invention] The purpose of the present invention is transparent! To provide an optical component made of plasticine coated with a multi-coating which has excellent properties, adhesion and durability, and which does not change over time.

[Summary of the invention]

In order to achieve this purpose, the present invention has adopted an anti-reflection coating with a polygonal structure, and has a layer of 5i02# on the plastic side, which has nine characteristics.

[Embodiments of the invention] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of an optical component made of plastic according to the present invention, and 1 is Ml! F2MII, 2 is Aβ20slfls' is 5i02fl, and 4 is a plasticized lens.

This example uses Plasti-9 Cleanse as an example, where the design wavelength is of course λθ, and the first breast on the air side has an optical film thickness of λo.
/4 MgFz layer 1, the refractive index is 1.38. Second
The layer is 11205 layer 2 with an optical thickness λo/4 and a refractive index of 1.60. The 39th optical film thickness is λo/4 to λ0
range, preferably λo/4, λo/2°3λo/4,
The refraction is 1.45 at 8102 fault 5 which is either λ0 or
It is. Plasti-9 Lens 4 is an acrylic lens with a refraction l 1.49.

Also, ^j! 2θS normal refraction black line 1. a2, but this is the value that can be achieved when the substrate temperature t is 200℃ or higher, and when the substrate temperature cannot be raised like plastic, the refraction of 4ffi20g is 1.60
The above refraction force is rounded.

This example c/) S1021ta3 functions as an adhesive layer with the plastic substrate and as a damper that absorbs thermal expansion sound during a heat resistance test. Sunawachi 1.
6. O2 has excellent adhesion with □2og ratio -, 1, pu, 7, 21, as well as excellent flexibility and intermolecular bonding force, and has a large thermal expansion difference with plastic. However, during the heat resistance test, 7. No cavities occur. However, the aforementioned
Among plastics, acrylic has a particularly weak adhesion to inorganic materials (if it is thicker than α5/Jm,
It was not possible to use the conventional 5102 method applied to 0R-39 and the like for acrylic lenses because the adhesion strength was reduced and cracks were generated in heat resistance tests. -10,000, if S10zk50nm or more is set to 1, 51
02 does not work well as a damper, and received an A rating in the heat resistance test.
A crash occurs in jt20s#2. In this way, 5102 fist 3 has an appropriate range, and 50n
It was found that a value of m or more and a5#m or less is appropriate9.

・Also, Mg1112 in the 1st h, kit2ys in the 2nd fat
, and the 3111th and 8102nd refractive forces were investigated.

FIG. 2 is a graph showing the time-dependent changes in the refraction force of the materials forming each layer, and shows the 1! The material forming the r layer is conventional Si.
It was found that refractive straw hardly changes over time compared to O. Therefore, 4! The antithesis of r[, 8.

The radiation prevention properties and (t) transmission amount properties also do not change over time.

FIG. 3 is a diagram showing two spectral reflection characteristics of the % layer shown in FIG.

In the same figure, the curve! ! i, '6.7 is 5i02 chest optical membrane angle λ0/4 (94,8・zen), λo/
2 (19 onm).

Here, the design wavelength λ0 is 550 nm. As mentioned earlier 51
02 The film thickness on the chest should be 50nm to α5/1m, but considering the fractional reflection straw characteristics, the optical film thickness should be λo/4 to
A range of λ0 is preferable, and furthermore, 5i02jF
Optical film thickness of l λo/4'+λo/2 ・SA'o/
It is desirable to provide power to a or λ0.

In order to form an antireflection film on the acrylic lens of this example, 5i02 is deposited on the surface of the acrylic substrate by electron beam heating evaporation until the required film thickness is reached. , also by electron beam heating evaporation method")%
1M20s and 1M2'lt are deposited in that order until a predetermined film thickness is reached.

As described above, in this example, the antireflection effect, W
It is possible to obtain a multi-coating that has excellent jW properties and heat resistance and does not change over time.

FIG. 4 is a 1ilT side view of an optical component made of plastic according to an embodiment of the present invention, where 8 is) JL'FJi, 9
is Zr021i1. ” is 5102Jill, and 11 is a polycarbonate lens.

The first layer on the air side is Mf! F'2-, and the second layer is Zr
The O2 layer and the third layer is the 8102 breast. When the design wavelength is λ0, the optical thickness of each layer is λ0/4 for MgF21tII8, which is the first glaze, and Zr, which is the second IiI.
The O2 layer 9 is λ0/2, and the 3111Mth SiO2mLD is λ0/2.

To make such a plastic lens, first,
8102 on the surface of a substrate made of polycarbonate? I-
The film is deposited to a predetermined thickness using an evaporation method using electron beam heating.
Furthermore, two films are fabricated in order of KZr02 and MgF21t to a predetermined thickness by electron beam heating evaporation. 8102
It is also possible to perform ion bombardment by introducing an Ar gas atmosphere and applying a high frequency voltage to generate plasma before vapor depositing the polycarbonate, thereby activating the polycarbonate surface and increasing the adhesion. Also, 5i02*ZrO2+M
It is also possible to produce part or all of each gr2 breast using the ion-blating method. The 5102 layer 10 in this embodiment functions as a dense N-thickness between the plastic substrate 11 and the Zr02 layer 9, and as a damper to absorb thermal expansion sound during a heat resistance test. In other words, 5io2 has better adhesion to plastic than ZrO2, and even though it has excellent flexibility and a large difference in thermal expansion from plastic, cracking occurs during heat resistance tests. There is no. For example, inserting a 5iOa fist into a polycarbonate base material,
Direct Z r02 layer and MF! When installed in F2#, cracking occurred in the 80°C heat resistance test, and it was reduced to a transparent straw or a large pot. In contrast, 5i02'' below a51Im!
By providing a ZrO2 layer and a MgF2 layer with a ZrO2 layer and a MgF2 layer, it was possible to prevent cracking noise during a heat resistance test at 80°C. - As mentioned earlier, installing a 5102 C IQi of 151 m or more will cause a large bending in the 80°C heat resistance test due to a decrease in adhesion and an increase in internal stress.

Furthermore, in this zero embodiment, among the 5ioh axes of 1571 m or less, the 8102 fist 100 elemental membrane Jl meeting λ0/2 is set. Here, for example, the design wavelength λ0'ft is the normal 55
If it is 0 nm, the refraction is 8.102! is 1.45, so if it is converted to optical film thickness λG/2, α1
9〃m and 9, [L5J1m or less φ condition is satisfied.
゛Figure 5 is a characteristic diagram of the 8102 fist reflex,
12.13 and 14 spectral reflection curves.

In the β1 diagram, the first fist is Mj'l'*l1i8, and the second fist is Zr.
02 layer 9, the third layer is 5102 10, the base material '9 is a refractive straw 1.58 polycarbonate lens 11, the optical thickness of each layer is 'i, the Mg1F2 layer is λ074. It shows the spectral reflection of 8% when the film thickness of 5102 fist 10 is changed, with λ0/2 set as ZrO2 leakage 9'. Here, song 11i112 is by Honjitsu ml91+ and is 510
The optical film thickness was set to λo/2. Curve t? i and 14 are comparative examples for this example, and the IIFI line 13 has an optical film thickness λ of 8102, respectively.
0/4, curve 14 is 5102 1lIJII't-'#
m as i. In addition, 12. The design wavelength λ0 is 550 nm%.The refraction straw of MgF2 eB is 1.38, and the refraction straw of ZrO2111 is 1.90. 8
102M) The refraction sign of 10 is 1.45. ZrO2
The refraction of plastic straw is usually 2.05 to 2.10, but the plastic layer cannot be heated on the substrate, so it is evaporated at room temperature, and the normal one is evaporated at 200℃ or higher on the ridge of the lath lens. 9 different from the time, refraction IK line low around 1.90)
Therefore, in this example, the refractive force i of ZrO2 was set to 1.90. From FIG. 5, like this example,
By setting the optical thickness of 5to2e to λo/2,
Reflection NK can be reduced in a long wavelength region. On the other hand, the optical thickness of 5io2 fist is λo/2
Very thin λG/ 14 K Lft J), λo/2(
If the width is set to 1 μm (equivalent to a19am), the spectral reflection property of 8% will deteriorate noticeably.

In addition, in this example, 5i0, which has little change in refractive error over time, is used.
2 and Zr0z, MgF2t? Because it is used, there is little change in the spectral transmission X characteristics over time. Also 8102 layer IQ
By setting the value to 11-α5Am or less, it was possible to prevent cracking in a heat resistance test at 180°C.

Note that in the above two embodiments, acrylic lenses and polycarbonate lenses have been described, but plastic lenses among them can also be used.

〔Effect of the invention〕

As explained above, according to the present invention, the transmittance characteristics,
Since it has excellent layer density and heat resistance, and can be coated with a multi-coating that does not change over time, it is possible to eliminate the drawbacks of conventional methods and provide optical components made of plastic with nine functions.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of an optical component made of plastic hammered according to the present invention, FIG. 2 is a characteristic diagram showing changes over time in FIG. 1, and FIG. 3 is a spectral reflection screen characteristic diagram in FIG. 1. FIG. 4 is a cross-sectional view of an optical component made of Plastilif according to another embodiment of the present invention, and a diagram showing the spectral reflection characteristics of 5i (127il) in FIG. ,s・−・F1
02rflj. 4...Plastic lens, 5.6 and 7...Spectral reflectance chart curve, 8-MgF2Jiil, 9-Zr02
Jil, 10...sio2m. Talent 1 Illustration talent? Vice 0.1 / /D 10゜Rice period meat (day) f3 eyes 2 gray length (?1rn) year old 4 figure

Claims (1)

[Scope of Claims] (1) In an optical component made of plastic having a multilayer anti-reflection coating on the surface of the plastic, the layer formed in I-contact on the surface of the plastic of the multilayer anti-reflection coating starts from 5102. Narukoto 11t features original parts made of plastic. (2. In claim (1), the above-mentioned 510
An optical component made of plastic, characterized in that K All 2'Os Jil is formed on the layer of No. 2, and two layers of M12'F' are further formed thereon to form a 31i11 anti-reflection film. (3) In claim (1), the above-mentioned 81
Zr02Jil is on the 02 layer, and Mg1 is further on top of it.
An optical component made of Plastirif, characterized in that two layers are formed extensively to form a three-layer anti-reflection coating.