JP2003131010A - Optical parts, optical unit and graphic display device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for preventing cracks from occurring on an antireflection coating for optical parts whose base material has an antireflection coating provided on both sides. SOLUTION: On each side of the base material, the optical film thickness of a thin film of the first layer which is formed at the nearest position from the base material surface is made to be different from each other on either side of the base material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical component such as a lens, a filter, etc., in which an antireflection film having a multilayer structure is formed on both sides of a light-transmitting substrate such as a glass material or a plastic material.

[0002]

2. Description of the Related Art In recent years, optical components such as lenses and filters have been
As a material, many plastic materials are used instead of inorganic glass.
It has become popular. In general, optical components
Reduces reflectance in the visible light band to improve optical performance such as transmittance.
In order to improve, an antireflection film is formed on the surface. An example
For example, Japanese Patent Laid-Open No. 10-39104 discloses a plastic clip.
As a plastic optical component such as cleanse, plastic
5 layer anti-reflective coating by vacuum deposition on the substrate surface
The first layer, the third layer, and the fifth layer on the substrate surface side are provided with SiO.
_Two, The second and fourth layers are made of ZrO_TwoAnd TiO_TwoMixture with,
Or Ta_TwoO ₅When composed of a high refractive index material such as
In general, the optical thickness of the first layer is set in the wide band of visible light or the like.
Described is a configuration that reduces the design wavelength, which is the core wavelength, to approximately 1/2.
As a result, the adhesion to the plastic substrate is good.
And it is possible to obtain an optical component having high environmental resistance.
It is said that

[0003]

FIG. 2 shows a case in which an antireflection film having a five-layer structure according to the technique described in the above publication is formed on both sides of a plastic base material. Figure 2
1, 101 is a plastic optical part, 2 is a base material of the plastic optical part 101, and 103 is a film of a low refractive index material and a film of a high refractive index material alternately deposited on one surface of the base material 2. It is an antireflection film having a five-layer structure formed in this way. 109 is similarly formed on the other surface of the base material 5
It is an antireflection film having a layered structure. When making,
The base material 2 of the plastic optical component 101 is fixed to a base material holder in a vacuum vapor deposition device (not shown). Next, the inside of the vacuum chamber is evacuated, and the deposition material is deposited by the electron beam deposition method on the substrate
It vapor-deposits on one surface (henceforth a surface) of one, and the antireflection film 103 of a 5-layer structure is formed. The antireflection film 103 is
From the first layer 104 in contact with the base material 2, the second layer 105, the third layer 106, the fourth layer 107, and the fifth layer 108 are sequentially vapor-deposited in order outwardly until they have predetermined film thicknesses. 1st layer 1
04, the third layer 106, and the fifth layer 108 are layers of SiO ₂ which is a low refractive index material, and the second layer 105 and the fourth layer 107 are layers of a high refractive index material. After forming the antireflection film 103 on the surface of the base material, the base material 2 is inverted, and then vacuum evaporation is also performed on the back surface of the base material to form the antireflection film 109 having a five-layer structure. The antireflection film 109 is formed in order from the sixth layer 110 in contact with the base material 2 to the outside until the seventh layer 111, the eighth layer 112, the ninth layer 113, and the tenth layer 114 each have a predetermined film thickness. Evaporate in sequence. The antireflection film 109 includes a sixth layer 110 and an eighth layer 112.
And the tenth layer 114 is made of SiO ₂ which is a low refractive index material and the seventh layer.
The layer 111 and the ninth layer 113 are made of a high refractive index material. In such a configuration, the antireflection film 103 on the surface of the base material 2
Then, the antireflection film 109 on the back surface has almost the same optical film thickness, and there is almost no difference. When the design wavelength, which is the central wavelength of a wide band such as visible light, is λ ₀ , the difference in optical film thickness is ±
It is within 0.03 · λ ₀ . That is, the first layer 104 and the sixth layer 110, the second layer 105 and the seventh layer 111, the third layer 10
6 and 8th layer 112, 4th layer 107 and 9th layer 113, 5th
The optical thicknesses of the layer 108 and the tenth layer 114 are substantially equal.
When the substrate 2 is automatically inverted in the film forming process of the antireflection film, the evacuation process can be performed once, which can significantly reduce the time required for the film forming process. It will be possible. However, in this method, in general, film formation is continued without breaking the vacuum in the vacuum chamber of the vacuum vapor deposition apparatus, so that the film formation start vacuum degree of each layer gradually increases and becomes a high vacuum. Therefore, even if the same vapor deposition material, the same vapor deposition rate, and the same film thickness, the formed thin films have different stresses, and the first layer 104 to the fifth layer of the antireflection film 103 are different.
The balance of the film stress up to the layer 108 and the antireflection film 109
The balance of the film stress from the sixth layer 110 to the tenth layer 114 is different. Therefore, the adhesion of the film is different between the antireflection film 103 that is formed first and the antireflection film 109 that is formed later, which causes the occurrence of cracks. Further, in a concave lens having a cross section as shown in FIG. 3,
One surface has a compressive stress in the direction of the arrow, and the other surface has a tensile stress. When an antireflection film is vapor-deposited on both surfaces of such a concave lens, the difference in stress causes cracks in the antireflection film. Further, when a lens having an antireflection film on both sides is used in an image display device or the like, one side is heated by light from a lamp or the like, and the other side is cooled by a cooling mechanism or the like, A temperature difference may occur between the two surfaces. Even when the usage environment is different on both surfaces of the lens in this way, it also causes cracks in the antireflection film. The problem of the present invention, in view of the situation of the above-mentioned prior art,
In optical parts with anti-reflective coating on both front and back sides of the base material,
To prevent cracks in the antireflection film,
Is. An object of the present invention is to provide a technique capable of solving such a problem.

[0004]

In order to solve the above-mentioned problems, in the present invention, as a constitution of a multilayer antireflection film formed on both surfaces of a light-transmitting substrate, To be formed at a position closest to the substrate surface on the side of
The optical film thickness of the thin film of the second layer is different from each other on both sides of the base material. (2) The film thickness difference is set to be approximately ¼ or more of the wavelength of light in the visible light band. (3) The film thickness difference is set to be approximately ¼ or more of the center wavelength of the visible light band.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1, FIG. 4, FIG. 5, and FIG. 6 are explanatory views of the optical component of the present invention, FIG. 1 is a structural example diagram of the optical component of the present invention, and FIG. 4 is a spectral reflectance of the optical component of the present invention. FIG. 5 is a diagram showing an example of the calculation result, FIG. 5 is a diagram showing the optical film thickness and refractive index of the optical component used in the calculation of FIG. 4, and FIG. 6 is a diagram showing the measurement result of the spectral transmittance of the optical component of FIG. is there.

In the calculation of FIG. 4, as the base material,
Folding rate n = 1.495 polymethylmethacrylate (hereinafter
Below, PMMA) using a plastic material,
A five-layer antireflection film shall be formed on the surface.
It was As the antireflection film, as shown in FIG.
In order from the side, the refractive index of the first thin film of the antireflection film
1.46, the refractive index of the second thin film is 1.86, the third layer
The refractive index of the thin film of the eye is 1.46, the refractive index of the thin film of the fourth layer
And the refractive index of the fifth thin film is 1.38,
By changing the optical thickness of the thin film of each layer, 7 combinations are set.
Decided In addition, the design has a central wavelength of a wide band such as visible light.
Wavelength λ₀Was 520 nm. First combination
(Hereinafter, referred to as No. 1 case), the thinness of the first layer
The optical thickness of the film is 0.075 · λ₀, Of the second thin film
Optical film thickness of 0.070 · λ₀, Optics of the third thin film
Film thickness of 0.102 · λ₀, A fourth thin film optical film
Thickness is 0.523 · λ₀, The optical thickness of the fifth thin film
0.248 · λ₀I am trying. Book No. 5 in 1 case
The spectral reflectance of the layered antireflection film is calculated as follows:
As shown in FIG. 4, “in the wavelength range of 420 to 680 nm,
Has a spectral reflectance of 0.5% or less. "
(No. 1 in FIG. 4). In addition, the second combination (below
Below, No. 2), the first layer of thin film
Optical film thickness of 0.325 · λ₀, Optics of the second thin film
Film thickness of 0.053 · λ₀, A third thin film optical film
Thickness is 0.109 · λ₀, The optical thickness of the fourth thin film
0.514 · λ₀, The optical film thickness of the fifth thin film is set to 0.
247 · λ₀And the above No. Based on case 1
The optical thickness of the first layer is + (1/4) · λ₀Thickened, second
The optical thickness of each layer from the fifth layer to the fifth layer is 1 case
Approximately ± 0.03 · λ from the optical film thickness ₀Adjust the range of
It is the value you went to. Book No. Spectroscopy in case 2
As shown in FIG. 4, the reflectance is also calculated as “wavelength 4” in the calculation result.
Spectral reflectance within 20 to 680 nm is 0.5% or less. "
The specifications are satisfied (No. 2 in FIG. 4). Furthermore
To the third combination (hereinafter referred to as No. 3 case)
Then, the optical thickness of the first thin film is 0.575.
λ₀, The optical thickness of the second thin film is 0.068
λ₀, The optical thickness of the third thin film is 0.112.
λ₀, The optical thickness of the fourth thin film is 0.533.
λ₀, The optical thickness of the fifth thin film is 0.252 · λ₀
And the above No. Based on case 1, the first layer of optics
Film thickness is + (2/4) · λ₀Thicker, 2nd to 5th layers
The optical film thickness of each layer is set to No. 1 case optical film
About thickness ± 0.03 ・ λ₀The value after adjusting the range of
ing. Book No. The spectral reflectance in the case of 3 is also
The calculation result shows that "spectral reflection within the wavelength range of 420 to 680 nm
The rate is 0.5% or less ”(Fig. 4
No. 3). The fourth combination (hereinafter, No. 4 case)
The optical thickness of the first thin film is 0.8
25 · λ₀, The optical thickness of the second thin film is 0.059.
λ₀, The optical thickness of the third thin film is 0.097.
λ₀, The optical thickness of the fourth thin film is 0.502.
λ₀, The optical thickness of the fifth thin film is 0.244 · λ₀
And the above No. Based on case 1, the first layer of optics
Film thickness is + (3/4) ・ λ₀Thicker, 2nd to 5th layers
The optical film thickness of each layer is set to No. 1 case optical film
About thickness ± 0.03 ・ λ₀The value after adjusting the range of
ing. Book No. The spectral reflectance in the case of 4 is also
The calculation result shows that "spectral reflection within the wavelength range of 420 to 680 nm
The rate is 0.5% or less ”(Fig. 4
No. 4). In addition, the fifth combination (hereinafter, No. 5
In this case, the optical thickness of the first thin film is
0.530 · λ₀, The optical thickness of the second thin film is set to 0.
061 / λ₀, The optical thickness of the third thin film is set to 0.10.
0 · λ₀, The optical thickness of the fourth thin film is 0.513 · λ
₀, The optical thickness of the fifth thin film is 0.247 · λ₀When
The above No. Based on the case of 1, the optical of the first layer
The film thickness is + (1.82 / 4) · λ₀Thicken, from the second layer
The optical thickness of each layer of the fifth layer is 1 case optics
± 0.03 · λ from the typical film thickness₀The value after adjusting the range
I am trying. Book No. Spectral reflectance in case 5
Also, the calculation result shows that "the wavelength within 420 to 680 nm
The light reflectance is 0.5% or less "
(No. 5 in FIG. 4). Sixth combination (hereinafter, No.
6), the optical thickness of the first thin film
0.793 · λ₀, The optical thickness of the second thin film
0.060 · λ₀, The optical thickness of the third thin film is set to 0.
103 · λ₀, The optical thickness of the fourth thin film is 0.51
2 · λ₀, The optical thickness of the fifth thin film is 0.244 · λ
₀And the above No. Based on the case of 1, the light of the first layer
Film thickness + (2.87 / 4) · λ₀Thicken, second layer
The optical thickness of each layer from the fifth layer to the fifth layer is One case
Approximately ± 0.03 · λ from optical film thickness₀Adjust the range of
Value. Book No. Spectral reflection in case 6
As for the rate, the calculation result shows that "in the wavelength range of 420 to 680 nm,
Spectral reflectance is 0.5% or less ”
(No. 6 in FIG. 4). Furthermore, the seventh combination (below
Below, No. 7)), the thin film of the first layer
Optical thickness 0.700 · λ₀, Optics of the second thin film
Film thickness is 0.066 · λ₀, A third thin film optical film
Thickness is 0.114 · λ₀, The optical thickness of the fourth thin film
0.541 · λ₀, The optical film thickness of the fifth thin film is set to 0.
254 / λ₀And the above No. Based on case 1
The optical thickness of the first layer is + (2.5 / 4) · λ₀Thicken,
The optical thickness of each of the second to fifth layers is set to No. One
Approximately ± 0.03 · λ from the optical film thickness of the case₀Range of key
It is the adjusted value. Book No. In case 7
In the calculation result, the spectral reflectance is also "wavelength 420 to 680n.
Satisfies the specifications that the spectral reflectance within m is 0.5% or less "
(No. 7 in FIG. 4).

In FIG. 4 and FIG. 5, the No. 2, No.
3, No. 4, No. 5, No. 6, No. 7 cases
In each case, the optical thickness of the first layer is + (1 /
4) ・ λ ₀If changed, + (2/4) · λ₀Changed place
+ (3/4) ・ λ₀If it changes, + (1.82 /
4) ・ λ₀If changed, + (2.87 / 4) · λ₀change
If you do, + (2.5 / 4) · λ₀Examples of changes
As shown, the film thickness of the first layer is (1/4) · λ₀Greater than
The same applies to the case of a sharp change. Result of the above calculation
Therefore, in the five-layer structure antireflection film, the light of the first layer
When the optical film thickness is changed by (1/4) or more of the design wavelength λ
However, the effect on the spectral reflectance characteristics is small,
The optical thickness of the fifth layer is also the predetermined optical thickness
It was found that it can be adjusted within a range of approximately ± 0.03 ・ λ
did. Regarding the film stress, the change of (1/4) · λ
In case of film stress >>
Therefore, the film stress balance is better than that of the other layers in the shadow of the first layer.
It receives a great sound.

FIG. 1 shows the optical part of the present invention based on the above results.
In the example of the product, a configuration example having a five-layer structure antireflection film
is there. In FIG. 1, 1 is a plastic optical component, 3
Is a five-layer antireflection film formed on the front surface side of the substrate 2,
Reference numeral 9 is a reflection of a five-layer structure similarly formed on the back surface side of the base material 2.
It is a prevention film. The configuration of this embodiment is the same as that of the conventional technology shown in FIG.
Unlike the above, the thickness of the layer in contact with the base material 2 is
The layers on the surface side are different. The optical part made of plastic
Design wavelength λ of product 1₀Is the center wavelength of a wide band such as visible light
Λ₀= 520 nm, and the base material 2 is a PMMA lens
Therefore, the refractive index is 1.495. Of the optical component of the present embodiment
The manufacturing procedure is as follows:
Set it in the base material holder (not shown) of the vacuum evaporation system,
1.0 × 10 at a given temperature^-3After exhausting to below Pa,
The vapor deposition material is formed by electron beam vapor deposition on one surface of the substrate 2 (front surface).
To form a five-layered antireflection film 3 in sequence.
It At this time, each layer constituting the antireflection film 3 has the following properties.
Let's do it. In addition, the exhaust in the vacuum chamber is formed with an antireflection film.
It will continue during the period. First layer thin film 4
The respective layers of the fifth thin film 8 are as follows. First layer
The thin film 4 of the eye is made of SiO by the electron beam evaporation method._TwoA thin layer of
With the structure formed on the base material 2, the optical film thickness is 0.793.
λ₀, And the refractive index is 1.46. The thin film 5 of the second layer is
La by electron beam evaporation method_TwoO_ThreeAnd TiO _TwoOf a mixture of
With a structure in which a thin layer is formed on the first layer 4, the optical film thickness is
0.060 · λ₀, And the refractive index is 1.86. Third layer
The thin film 6 of SiO 2 is formed by the electron beam evaporation method._TwoA thin layer of
With the structure formed on the second layer thin film 5, the optical film thickness is
0.103 · λ₀, And the refractive index is 1.46. 4th layer
The thin film 7 of the eye is made of La by an electron beam evaporation method._TwoO_ThreeWhen
TiO_TwoA thin layer of the above mixture on the third thin film 6
With the formed structure, the optical film thickness is 0.512 · λ.₀,refraction
The rate is 1.94. The fifth thin film 8 is an electron beam
By vapor deposition method, MgF_TwoThin layer on the fourth thin film 7
The optical film thickness is 0.244 · λ₀,
The folding rate is 1.38. Next, invert mechanism (not shown)
Therefore, after automatically reversing the base material (while the vacuum tank is still vacuum
It is assumed that they are exhausting without being broken. ), Electronic
The beam evaporation method is used to form five layers on the other surface (back surface) of the base material 2.
The antireflection film 9 is the same as when the antireflection film 3 is formed.
It is formed by the same procedure. Each layer of the antireflection film 9 is as follows
Is. The sixth thin film 10 is made of Si by electron beam evaporation.
O_TwoIs formed on the substrate 2 with a thin layer of
0.325 · λ₀, And the refractive index is 1.46. 7th layer
The thin film 11 of La is formed by an electron beam evaporation method._TwoO_ThreeAnd TiO
_TwoForming a thin layer of the mixture on the sixth thin film 10
With the above configuration, the optical film thickness is 0.053 · λ₀, The refractive index
Set to 1.86. The eighth thin film 12 is an electron beam vapor
SiO by the dressing method _TwoA thin layer on the seventh thin film 11
The optical film thickness of 0.109 · λ₀, The refractive index
Set to 1.46. The ninth thin film 13 is an electron beam vapor
La in the dressing method_TwoO_ThreeAnd TiO_Two8th thin layer of mixture
It is formed on the thin film 12 of the layer and has an optical film thickness of 0.
514 / λ₀, And the refractive index is 1.94. 10th layer
The thin film 14 is formed of MgF by the same electron beam evaporation method._Two
Is formed on the thin film 13 of the ninth layer.
Film thickness 0.247 · λ₀, The refractive index is 1.38
It

As described above, in the present invention, after forming the five-layer antireflection film on the front surface side of the base material 2, the vacuum state in the vacuum chamber is not broken and the back surface side of the base material 2 is continued. The manufacturing procedure is to form a five-layer antireflection film on the substrate, and the second thin film, the seventh thin film, the third thin film, and the eighth thin film.
Although the film thicknesses of the thin film of the fourth layer, the thin film of the fourth layer and the thin film of the ninth layer, and the thin film of the fifth layer and the thin film of the tenth layer are almost the same, Of the antireflection film 3 firstly provided on the surface side of No. ₂ formed of SiO ₂
With respect to the thin film 4 of the first layer, the thin film of the first layer of the antireflection film 9 provided on the back surface side of the substrate 2, that is, the thin film 10 of the sixth layer is made to have a different thickness. By making the thin film and the sixth thin film have different film stresses from each other, the balance of the film stresses on both surfaces can be improved and the occurrence of cracks and the like can be suppressed.

FIG. 6 is a diagram showing the measurement results of the spectral transmittance as a lens of the optical component of FIG. As a result,
Spectral transmittance as a lens is 420nm-680nm
Is 99.0% or more in the visible light range. Further, the lens as the optical component was subjected to an environmental resistance test (a high temperature test at 70 ° C, a low temperature test at -40 ° C, a constant temperature and high humidity test at 60 ° C and 90%, and a test time of 2500 h). No cracks occurred and deterioration was less than 1.0%. Similar results were obtained in the case of a sample manufactured with a design wavelength λ _{0 of} about 480 nm.

The above-described technique of the present invention can be applied to, for example, a concave lens having stress distortion as shown in FIG.
In the case of the concave lens, the first antireflection film formed on the concave lens is provided on the surface of the concave lens substrate on which the crack is generated.
The film thickness of the thin film of the layer is, with respect to the predetermined film thickness on the other surface side,
If it is changed by (1/4) · λ or more to withstand the stress of the concave lens surface, cracks in the antireflection film can be reduced. In addition, the technique of the above-mentioned invention is, for example, as shown in FIG.
The present invention can be applied even when the environment in which the lens of the optical component is used causes a temperature difference on both surfaces of the lens. The thickness of the first thin film on the surface of the lens substrate where cracks occur is ¼ of the design wavelength with respect to the predetermined thickness of the thin film on the other surface.
By making the above change so as to withstand the temperature difference on the lens surface, it is possible to suppress the occurrence of cracks in the antireflection film.

According to the above embodiment, in an optical component using a plastic material as a base material, the film stress balance of the antireflection film on both surfaces of the base material can be improved, and the occurrence of cracks or the like in the antireflection film can be suppressed. .

Although PMMA is used as the base material of the optical component in the above embodiment, the present invention is not limited to this, and other materials such as a polycarbonate material may be used. Further, the present invention is suitable for an optical component using a plastic material as a base material, but is not limited to this, and can be applied to an optical component using a glass material as a base material. The range of optical components is not limited to lenses and filters.

FIG. 7 shows a configuration example of a video display device as an embodiment of the present invention. This image display device is an example of a projection type image display device that optically processes light from the light source side, irradiates the liquid crystal panel, converts it into light containing image information, and displays the image on a screen. In FIG. 7, 30, 36, 4
4 is a condenser lens, 40 and 42 are relay lenses, 4
Reference numeral 7 is a prism, and 48 is a projection lens unit for projecting light 49 emitted from the prism 47 onto a screen (not shown). For the condenser lenses 30, 36, 44, the relay lenses 40, 42, and the projection lens in the projection lens unit 48, the optical components having the configuration of the present invention are used. The white light flux 23 from the light source 21 is reflected by the reflector 22,
First lens array 24, cold mirror 25, and second
The lens array 26 forms a uniform white light beam, and the blue / green reflection dichroic mirror 27 separates the light beam into a red light beam 28 and a blue / green light beam 33. Red luminous flux 28
Is reflected by the increasing reflection mirror 29, and the condenser lens 30
Then, the light enters the transmissive liquid crystal panel 32 for red light.
The blue / green light flux 33 is separated into a green light flux 35 and a blue light flux 39 by the green reflection dichroic mirror 34.
The green light flux 35 is incident on the transmissive liquid crystal panel 38 for green light. The blue light flux 39 passes through the relay lens 40, the increasing reflection mirror 41, the relay lens 42, the increasing reflection mirror 43, and the condenser lens 44, and the transmission type liquid crystal panel 46 for blue light.
Is incident on. The red light flux emitted from the transmissive liquid crystal panel 32 for red light includes image information, the red light flux emitted from the transmissive liquid crystal panel 38 for green light and the green light flux including image information, and the transmissive liquid crystal panel 46 for blue light. The blue light flux containing the image information is incident on the prism 47. In the prism 47, the color light fluxes are combined and emitted toward the projection lens unit 48. Projection lens unit 48
Displays the image by enlarging the synthetic light as the image light and projecting it on the screen. The light source 21 is driven by the light source power supply circuit 80, and the liquid crystal panels 32, 38, and 46 are driven by the drive circuit 70 based on the video signal input from the input terminal 60, and the corresponding color luminous flux (color light) is modulated. Make it transparent. In the configuration of this embodiment, the light source 2
The optical components arranged in the optical path from 1 to the projection lens unit 48 form an optical unit.

According to the configuration of the above embodiment, it is possible to reduce the reflectance of light in each lens and improve the transmittance in the optical path in the optical unit. Also, the contrast of the image can be improved. Further, when the lens in the optical unit is a plastic lens, the weight of the device can be reduced.

Although the above embodiment is an example of the projection type image display device, the present invention is not limited to this.

[0017]

According to the present invention, in the optical component technology using a plastic material or the like as a base material, the film stress balance of the antireflection film on the surface of the base material can be improved, and the occurrence of cracks or the like in the antireflection film. Can be suppressed. Further, in the optical unit and the image display device using the optical component of the present invention, the reflectance of light can be reduced and the transmittance can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a sectional configuration of an optical component as an embodiment of the present invention.

FIG. 2 is a diagram showing a cross-sectional configuration example of an optical component according to a conventional technique.

FIG. 3 is a diagram showing a cross-sectional configuration example of a concave lens.

FIG. 4 is a diagram showing an example of calculation results of spectral reflectance in the optical component of the present invention.

5 is a diagram showing an optical film thickness and a refractive index of the optical component used in the calculation of FIG.

6 is a diagram showing a measurement result of a spectral transmittance of the optical component of FIG.

FIG. 7 is a diagram showing a configuration example of a video display device using the optical component of the present invention.

[Explanation of symbols]

1, 101 ... Plastic optical parts, 2 ... Base material,
3, 9, 103, 109 ... Antireflection film, 4, 104 ...
First layer thin film, 5, 105 ... Second layer thin film,
6, 106 ... Third layer thin film, 7,107 ... Fourth layer thin film, 8,108 ... Fifth layer thin film, 10,11
0 ... 6th layer thin film, 11, 111 ... 7th layer thin film, 12, 112 ... 8th layer thin film, 13, 113
... thin film of 9th layer, 14, 114 ... thin film of 10th layer, 30, 36, 44 ... condenser lens, 40,
42 ... Relay lens, 48 ... Projection lens unit,
70 ... Driving circuit, 80 ... Power source circuit for light source.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Sadayuki Nishimura             292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Ceremony Hitachi Digital Media System             Within the business division F-term (reference) 2H091 FA10Z FA26Z FA37Z FB02                       FD06 FD23 LA02 MA07                 2K009 AA09 BB02 BB14 CC03 CC06                       DD03 FF02

Claims (7)

[Claims] 1. An optical component in which a multilayer antireflection film is formed on both surfaces of a light-transmissive base material, wherein the antireflection film is formed on the base material surface on both sides of the base material. An optical component, wherein the first-layer thin film formed at a position close to each other has different optical film thicknesses on both surfaces of the base material. 2. An optical component in which a multilayer antireflection film is formed on both sides of a light transmissive base material, wherein the antireflection film is formed on the base material surface on each side of the base material. The first-layer thin films formed at close positions have different optical film thicknesses on both surfaces of the base material, and the film thickness difference is about ¼ or more of the wavelength of light in the visible light band. An optical component characterized in that 3. The optical component according to claim 2, wherein the antireflection film has a difference in film thickness that is approximately ¼ or more of a central wavelength of a visible light band. 4. The antireflection film has a thickness difference of about 1
The optical component according to claim 2, which has a thickness of 20 nm or more. 5. The optical component according to claim 1, wherein in the antireflection film, the first thin film is made of SiO ₂ . 6. An optical unit having a structure for irradiating a panel with light from the light source side to emit modulated light, comprising: a first lens for transmitting light from the light source side; and irradiating through the lens. A panel that emits light that is modulated based on a video signal and that is emitted, and means that synthesizes the emitted light from the panel,
And a second lens for projecting the combined light, wherein one or both of the first lens and the second lens has a multilayer antireflection film on both surfaces of a light-transmitting base material. A thin film of the first layer, which has a formed structure and in which the antireflection film is formed at a position closest to the base material surface on each side of the base material, is formed on both surfaces of the base material. An optical unit, wherein the optical film thicknesses are different from each other, and the film thickness difference is about ¼ or more of the wavelength of light in the visible light band. 7. A lens that transmits light from the light source side, a panel that modulates and radiates light that has passed through the lens and is emitted based on a drive signal, and the panel is driven by a drive signal based on a video signal. A driving circuit, means for synthesizing light emitted from the panel, a second lens for projecting the synthetic light, and a power supply circuit for driving the light source, the first lens, the second lens One or both of the lenses has a structure in which a multilayer antireflection film is formed on both surfaces of a light-transmissive base material, and the antireflection film has the base material on each side of the base material. First formed at the position closest to the material surface
The thin film of the second layer has an optical film thickness different from each other on both sides of the substrate, and the film thickness difference is approximately 1/1 of the wavelength of light in the visible light band.
An image display device, characterized in that the number is four or more.