JPH116050A - Optical member and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply/easily form an optical thin film having a fine/complex pattern by removing a resist together with an optical thin film and leaving a optical thin film having a prescribed pattern shape after a resist is formed on a transparent substrate, further an optical thin film is formed on a whole substrate face. SOLUTION: A resist 2 is formed on a surface of a transparent substrate 1 of glass, plastic, etc., by an ink jet method, etc. Next, an optical thin film 3 is formed on a whole face of the transparent substrate forming the resist 2 by a vacuum deposition method, a sputtering method, a CVD method, etc. Successively, the resist 2 is peeled or dissolved to be removed and the optical thin 3 on the resist 3 is removed, the optical thin film 3, which has a pattern opposite to a pattern of the resist 2 on the transparent substrate 1, is left. By this method, an optical thin film having a fine/complex pattern is easily formed with a simple device at a good yield.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical member used as an internal optical component of a head mounted display or a video camera, and more particularly to an optical member having different spectral characteristic areas in a plane and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, in optical devices such as a head-mounted display and a video camera, a portion that reflects a specific wavelength within a plane and a portion that transmits the wavelength have been developed in accordance with the development of technologies such as line-of-sight input and position detection. The necessity of having an optical member is increasing.

In recent years, with the miniaturization of optical systems, their patterns tend to be finer and more complicated.

[0004] Such an optical member is basically formed by forming an optical thin film in a predetermined pattern on a transparent substrate, and the optical thin film has a pattern shape only at a central portion and an opening at the central portion. Having a part.

Here, when an optical thin film having the above-mentioned pattern is formed, it can be easily manufactured by forming the film using a mask having an opening at the center. However, when forming an optical thin film having the above pattern, the mask must be shielded only at the central portion, but the mask requires a support portion, and the support portion becomes a shadow and hinders the film formation. Therefore, it is impossible to form a film over the entire region to be formed in one step. Therefore, the film forming process is
It needs to be done more than once.

[0006]

However, the film formation process divided into a plurality of times not only complicates the manufacturing process but also increases the incidence of defective products and lowers the yield. When a mechanical mask such as a shielding mask is used, it is difficult to form a fine and complicated pattern with high accuracy. As a method for forming such a fine pattern, a method using a photoresist is suitable. However, the use of a photoresist complicates the process of forming an optical thin film, and also requires an exposure machine, a developing machine, and the like. The equipment becomes expensive and the cost of the optical member increases. Further, depending on the type of the resist, a special organic solvent, an alkaline developer, a peeling device, and the like are required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is intended to provide a highly reliable optical member at a low cost by forming an optical thin film having a fine and complicated pattern by a simple process. is there.

[0008]

The first aspect of the present invention is a method for manufacturing an optical member having an optical thin film pattern on a transparent substrate, and forming a resist by applying a resist material on the transparent substrate by an ink jet method. And a step of forming an optical thin film on the entire surface of the transparent substrate, and a step of removing the resist together with the optical thin film thereon to leave an optical thin film of a predetermined pattern on the transparent substrate. I do.

A second aspect of the present invention is an optical member manufactured by the above manufacturing method.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic sectional view showing the steps of the manufacturing method of the present invention. In the present invention, first, a resist material is applied on the transparent substrate 1 by an ink-jet method to form a resist 2. That is, drawing is performed on a transparent substrate using a resist material as ink in the ink jet method, and a resist 2 having a desired pattern is formed (FIG. 1).
(A)).

In the present invention, as the transparent substrate 1, a commonly used optical substrate material such as glass or plastic is used. Further, as a resist material, such as a material in which a polymer material is dissolved in an organic solvent, a material in which a dye or starch is dispersed in water, and the like can be provided on a transparent substrate as fine ink particles by an inkjet method, In addition, any solid component that remains on the transparent substrate after drying can be used.

As an ink jet system, a bubble jet type using an electrothermal converter as an energy generating element, a piezo jet type using a piezoelectric element, or the like can be used.

An optical thin film 3 is formed on the entire surface of the transparent substrate 1 on which the resist 2 has been formed (FIG. 1B). The film formation method may be selected depending on the material of the optical thin film 3, and for example, a vacuum evaporation method, a sputtering method, a CVD method, or the like is used.

The resist 2 is removed by stripping or dissolving (FIG. 1C). At the same time, since the optical thin film on the resist 2 is also removed, the optical thin film 3 having a pattern opposite to the pattern of the resist 2 is left on the transparent substrate 1.

According to the present invention, since a resist having a fine and complicated pattern can be easily formed in one step, an expensive apparatus or the like is not required as the resist forming step, and the yield is good. is there.

FIG. 6 is a schematic view of an optical system using the optical member of the present invention. This optical system is a line-of-sight input optical system, and the observation optical element 61 used in the optical system is the optical member of the present invention, and the surface B is shown in FIG. In this optical system,
The image displayed on the image display means 62 is displayed on the observation optical element 61.
At the same time, the eyeball is illuminated by the infrared light source 63, and the reflected light is taken out from the transmission area D provided on the surface B of the observation optical element 62 to the back, thereby enabling image recognition by visual observation. Infrared light is guided to the light receiving element 66 through the rear wedge prism 65 and the imaging optical system 64,
It detects the movement of the eyeball. As the optical thin film 3, for example, a metal thin film is used, and is configured to reflect light in regions other than the region D.

[0017]

【Example】

Example 1 A circular resist pattern of φ3 mm was drawn on an optical glass substrate of 70 mm × 50 mm and 10 mm thick by an ink jet method. The resist used here is
A solution obtained by dissolving 5% by weight of starch in pure water was used.

After drying the substrate at 80 ° C. for 5 minutes,
The apparatus was set in a vacuum evaporation machine, and was evacuated for 1 hour while heating the substrate to 200 ° C. in order to increase the adhesion between the substrate and the deposited film. Thereafter, 100 n of aluminum is applied to the entire surface of the substrate.
After the resistance heating evaporation to a thickness of m, the SiO was changed to λ / 2 (λ = 55
0 nm) Vapor deposition was performed by resistance heating, and it was taken out from the vacuum vapor deposition machine.

The above substrate is immersed in pure water, and 5
After washing for minutes, the resist was removed together with the deposited film thereon, followed by drying with warm air to obtain an aluminum pattern mirror as shown in FIG.

In the pattern mirror obtained in this embodiment, the shape of the light transmitting portion 4 was close to a perfect circle, and there was no appearance defect such as a scratch, and the pattern mirror was formed very well.

Comparative Example 1 The same substrate as in Example 1 was prepared, and the same deposition process as in Example 1 was performed using two types of masks shown in FIG. That is, first, the vapor deposition is performed by shielding with the mask of FIG. 4A to obtain the vapor deposition film 51 in the pattern shape of FIG. 5, and the vapor deposition is further performed by using the mask of FIG. An aluminum pattern mirror having the same pattern as in No. 1 was obtained.

In this comparative example, the film wrapped around the gap between the mask edge and the substrate, and the edge was blurred. In addition, deviation occurred at the joint between the two masks, and a perfect circle could not be formed.

Comparative Example 2 An aluminum pattern mirror having the same pattern as in Example 1 was manufactured by the steps shown in FIG. That is, a positive resist is spin-coated on the same substrate 1 as in Example 1 so as to have a thickness of 3 μm to form a resist layer 31 (FIG. 3A). For 20 seconds (Fig. 3
(B)) Then, ashing was performed to form a resist 33 (FIG. 3C).

Aluminum and SiO are vapor-deposited on the entire surface of the substrate in the same manner as in Example 1 (FIG. 3D), and the resist 33 is removed together with the vapor-deposited film thereon by exposing and ashing from the rear surface of the substrate. Then, an aluminum pattern mirror having the same pattern as in Example 1 was obtained.

In this comparative example, the substrate cannot be heated to increase the adhesion between the deposited film and the substrate.
The adhesion of the resulting film to the substrate was weak.

FIG. 8 shows a flow chart of the steps of Example 1 and Comparative Examples 1 and 2. (A) in the figure is Example 1,
(B) is Comparative Example 1 and (c) is Comparative Example 2. In the case of (c) using the photolithography technique, not only the process is long but also the photolithography equipment is expensive, so that the obtained optical member is also expensive. In addition, since the film formation step requires evacuation time, the time ratio in the entire process is large. Therefore, it is advantageous to reduce the number of film formation steps as much as possible. However, in FIG. 3B, since it is necessary to combine a plurality of masks to form an island-shaped opening, the number of film formations is increased, and time is reduced. Disadvantageous.

Example 2 1 × 100 mm × 100 mm
A stripe pattern having a line width of 500 μm was drawn at a pitch of 1 mm on an acrylic substrate having a thickness of mm by an inkjet method. The resist used here was a mixture obtained by mixing and dispersing 15% by weight of ethylene glycol in pure water, 8% by weight of carbon black having a particle size of 2 μm or less as a solid component, and 5% by weight of hexanol.

After drying the substrate at 50 ° C. for 10 minutes,
It was set in the chamber of the sputtering device and evacuated for 10 minutes. Thereafter, an aluminum target was sputtered in an oxidizing atmosphere by an RF sputtering method. The conditions at this time are as follows: Ar gas flow rate 80 sccm and O ₂ gas flow rate 10
At a sccm, the degree of vacuum was 0.8 Pa. The RF discharge power was 500 W and the deposition rate was 3 nm / sec. Sputtering was performed under these conditions for 51 seconds to obtain an alumina film having a thickness of 153 nm.

Subsequently, the SiO ₂ target placed in the same chamber was sputtered. At this time, the discharge gas pressure and power were the same as those for the aluminum target, and the film formation rate was 5 nm / sec. Sputtering is performed under these conditions for 17 seconds, and 85 nm thick Si
An O ₂ film was obtained.

Thereafter, the substrate was taken out of the sputtering apparatus and subjected to ultrasonic cleaning with ethanol for 10 minutes to remove the resist together with the deposited film thereon, thereby obtaining a striped acrylic substrate having an antireflection film.

[0031]

As described above, according to the present invention,
An optical member having an optical thin film with a fine and complicated pattern can be easily formed without going through complicated steps or steps requiring expensive equipment.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing steps of a manufacturing method according to the present invention.

FIG. 2 is a view showing an aluminum pattern mirror formed in Example 1 of the present invention.

FIG. 3 is a schematic cross-sectional view showing a process of Comparative Example 2 of the present invention.

FIG. 4 is a view showing a mask used in Comparative Example 1 of the present invention.

FIG. 5 is a view showing a deposited film obtained in a first film forming step in Comparative Example 1 of the present invention.

FIG. 6 is a schematic diagram of a line-of-sight input optical system using the optical member of the present invention.

FIG. 7 is a diagram showing an optical member used in the optical system shown in FIG.

FIG. 8 is a flowchart of an example of the present invention and a comparative example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transparent substrate 2 resist 3 optical thin film 4 light-transmitting region 31 resist layer 32 photomask 33 resist 51 deposited film 61 observation optical element 62 image display means 63 infrared light source 64 imaging optical system 65 wedge prism 66 light receiving element

Continuation of the front page (72) Inventor Kenichi Iwata 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (2)

[Claims] 1. A method for manufacturing an optical member having an optical thin film pattern on a transparent substrate, comprising: applying a resist material on the transparent substrate by an inkjet method to form a resist; A method for manufacturing an optical member, comprising: a step of forming; and a step of removing the resist together with the optical thin film thereon to leave an optical thin film having a predetermined pattern on a transparent substrate. 2. An optical thin film pattern on a transparent substrate,
An optical member manufactured by the manufacturing method according to claim 1.