JPH04155215A - Manufacture of grating, and grating - Google Patents

Abstract

PURPOSE:To improve fixing to a base by applying magnetic colloidal fluid containing iron oxide particles having a required particle diameter on a magnetic recording medium on which a grating pattern is written by a magnetic head to make the pattern clear and laminating a transparent oxide layer. CONSTITUTION:A vertical magnetic substance such as CoCr is sputtered or treated similarly on a peripheral face of a cylindrical base 5 made of iron or the like thereby forming a grating forming member 1 with a magnetic recording medium formed in a thin film. A grating pattern is written on the medium 6 by a magnetic head 2, and magnetic colloidal fluid containing iron oxide particles having a particle diameter sufficiently small relative to a pattern pitch is applied, whereby the magnetic grating pattern is made clear. By further forming a transparent oxide layer 8 on the pattern, the layer 8 is tightly fixed to the base 5, realizing a highly fixed grating wherein the pattern is not damaged by mechanical contact or shock.

Description

[Detailed description of the invention] [Industrial application field] TECHNICAL FIELD The present invention relates to a grid manufacturing method and a grid.

[Prior Art] A desired lattice pattern is written on a magnetic recording medium formed in a thin layer on a substrate using a penetrating head, a magnetization pattern is formed according to the pattern, and the pitch of the Q magnetization pattern is A magnetic colloidal fluid containing iron oxide particles with a sufficiently small particle size is applied to the magnetization pattern to visualize the magnetization pattern.
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[Problems to be Solved by the Invention] According to the above method, it is possible to fabricate a grating with an extremely fine pitch, but the constant force applied to the substrate is not necessarily strong enough for the grating pattern visualized by magnetic colloidal fluid. However, there was a problem that the grid pattern was easily damaged by mechanical contact and impact.The present invention was made in view of the above-mentioned circumstances.
The purpose of the present invention is to provide a novel grid and a method for producing the grid that have excellent fixation properties on the substrate side.

[Means for Solving the Problems] The methods of claims 1 to 4 are "methods for producing a grating having a phase grating pattern."

! Both of the methods of claims 1 and 2 include writing a desired lattice pattern on a magnetic recording medium formed in a thin layer on a substrate using a recording head to form a magnetization pattern according to the above pattern; Magnet 4
The difference between the conventional method and the method of “visualizing with a colloidal fluid” is that
The same is true.

[Substrate) can be formed of metal, glass, resin, etc.

"Magnetic recording medium" is a perpendicularly magnetized film such as CoCr or Fe2O.
It can be formed as a horizontally magnetized film such as 3゛.

"Magnetic colloidal fluid" is a product in which fine powder of iron oxide is dispersed in a dispersion medium (petroleum solvent, water, etc.) along with an activator at the interface, and the particle size of the iron oxide particles is large enough to be magnetized! - The pitch is set to be sufficiently small (100 to 200 people) compared to the pitch of the venue.

When a magnetic colloid fluid is applied to the magnetized pattern, the magnetic pattern becomes visible.

In the method of claim 1, ``a transparent oxide layer is formed on the visualized lattice pattern.'' In the method of claim 2, ``a transparent oxide layer is formed on the visualized lattice pattern. A thin metal film is formed as a reflective film in accordance with the method described above, and a transparent oxide layer is formed on top of this metal film.

``Form a reflective film as a thin metal film that follows the unevenness of a lattice pattern'' means that the reflective film is so thin that the visualized unevenness of the lattice pattern appears as the unevenness of the metal film on the surface of the formed metal film. This means forming a reflective film on the surface.

The transparent oxide can be SiO□ or Ink (claims 3 and 4).

Further, the material of the metal film formed as the reflective film is preferably gold (claim 4), but aluminum, chromium, nickel, etc. can also be used.

The lattice according to claim 5 is the lattice itself produced by the above method. Note that the lattice pattern referred to in this specification is not limited to a single period pattern, but also includes a computer hologram pattern and the like.

The grating manufacturing method of the present invention is effective for manufacturing scales for various encoders, particularly for manufacturing scales for encoders that utilize shadow patterns by diffraction.

[Function] As described above, in the present invention, a transparent oxide layer is formed directly or via a metal film on the lattice pattern visualized by the magnetic colloidal fluid. This layer firmly fixes the visualized grating pattern to the substrate and at the same time functions as a strong protective layer for the grating pattern.

[Example code] Hereinafter, description will be given based on specific examples.

FIGS. 1 to 4 are diagrams for explaining the invention of claims 1 and 3 in detail.

In FIG. 1, reference numeral 1 indicates a grid forming member.

The lattice forming member l is made by sputtering a perpendicularly magnetized substance such as CoCr onto the curved surface of a cylindrical body made of iron or the like to a thickness of several thousand.
It is formed as a thin layered magnetic recording medium,
It is configured to rotate at a constant speed around an axis by a rotational drive means (not shown).

A magnetic recording medium is magnetized in a predetermined direction in its thickness direction.

While rotating the grating forming member 1 at a constant speed, the clock signal 3 is inputted to the magnetic head for perpendicular magnetization indicated by the reference numeral 2,
By writing over the entire circumference of the grating forming member 1, a grating pattern with a constant pitch can be formed as a magnetization pattern.

FIG. 2 schematically shows a state in which a magnetization pattern is formed.

Reference numeral 5 indicates a substrate, and reference numeral 6 indicates a magnetic recording medium.

The left-right direction in the figure corresponds to the rotation direction of the grid-forming member 1.

In the magnetic recording medium 6, a lattice pattern is formed as a magnetization pattern by an arrangement of minute magnetic domains in which the direction of magnetization in the thickness direction is alternately reversed.

The pitch of the pattern written by perpendicular magnetization is about 0.1 .mu.m at the minimum, and in this embodiment, it is about 0.1 to 2 .mu.m. Note that in the direction perpendicular to the drawing of FIG. 2, the state of FIG. 2 continues for a finite dimension.

When a magnetic colloidal fluid containing iron oxide particles with a particle size of 100 to 200 particles is applied to the magnetized pattern thus formed, the magnetic colloidal fluid 7 visualizes the magnetized pattern as a lattice pattern, as shown in FIG. be done. That is, the iron oxide particles contained in the magnetic colloidal fluid 7 gather at the boundaries of magnetic domains in the magnetization pattern and are distributed according to the magnetization pattern, thereby visualizing the magnetization pattern. In this state, the dispersion medium of the magnetic colloidal fluid 7 is evaporated by heating.

Subsequently, as shown in FIG. 4, a transparent layer 8 of oxide is formed on the visualized lattice pattern. In this example, the oxide is SiO□ and layer 8 is formed by sputtering.

The oxide layer 8 firmly fixes the grating pattern 7 onto the magnetic recording medium 6 . In this way, a desired grid can be produced.

The fifth to eighth @ are diagrams for explaining embodiments of the methods of claims 2 and 4.

The grid making member 1^ is made by forming a thin layer of magnetic recording medium as a horizontally magnetized film of several thousand layers on one side of a disk-shaped base made of glass or the like by coating Fe2O, etc.
It is rotated at a constant speed in the direction of the arrow by a rotation drive means (not shown).

While rotating the grating forming member l^ at a constant speed, by inputting the clock signal 3 to two magnetic heads for horizontal magnetization, a pattern according to 1.0 is written on the periphery of the grating forming member IA to create a magnetization pattern. Form.

FIG. 6 schematically shows the formed magnetization pattern. Reference numeral 5A indicates a substrate, and reference numeral 6A indicates a magnetic recording medium, and the magnetization pattern is formed as a pattern in which the direction of magnetization (indicated by arrows) parallel to the substrate surface is alternately reversed.

The left-right direction in FIG. 6 corresponds to the rotational direction of the grid forming member IA, and the state shown in FIG. 6 is finitely continuous in the direction perpendicular to the drawing. In this case, the pitch of the magnetization pattern is 1 to several μ
It is m.

By applying magnetic colloidal fluid 7 to this magnetized pattern, it can be visualized as a lattice pattern.

FIG. 7 schematically shows a visualized state of the magnetization pattern.

After the dispersion medium of the magnetic colloidal fluid 7 is evaporated, gold having a high reflectance is formed as a reflective film by vapor deposition or the like. Furthermore, a transparent layer of In2O is formed on this reflective film by sputtering or the like.

FIG. 8 schematically shows the lattice produced in this way.

Reference numeral 9 indicates a reflective film made of gold, and reference numeral 10 indicates a transparent layer made of In, 03. 6 Reflective film 9.

It is formed extremely thin, and the surface shape of the reflective film 9 has a lattice pattern 7.
The unevenness of the image should be expressed as is. Layer 9 can be of any suitable thickness.

In this way, a desired grid can be obtained.

[Effects of the Invention] As described above, according to the present invention, a novel lattice and a method for producing a lattice can be provided.

In the grating produced by the method of the present invention, the grating pattern is firmly fixed to the substrate side, and since the oxide layer effectively protects the grating pattern, the grating pattern will not be damaged by mechanical contact or impact. There is no. Furthermore, as a method of fixing the grid pattern on the substrate side, a method of coating the grid pattern with a transparent resin by dipping or spraying and solidifying it after the dispersion medium has been evaporated may also be used to form the oxide layer according to the present invention. is equally valid.

[Brief explanation of drawings]

1 to 4 are diagrams for explaining in detail the inventions of claims 1 and 3, and FIGS. 5 to 8 are diagrams for explaining the inventions of claims 2 and 4 in detail. . 1. IA, grating forming member, 2.2A, magnetic head, 700. Magnetic colloidal fluid, layer of 9010 reflective film, 6°10, oxide layer

Claims (1)

[Claims] 1. A method for producing a grating having a phase grating pattern, which comprises writing a desired grating pattern onto a magnetic recording medium formed in a thin layer on a substrate using a recording head, and following the pattern. forming a magnetization pattern, applying a magnetic colloidal fluid containing iron oxide particles whose particle size is sufficiently smaller than the pitch of the magnetization pattern to the magnetization pattern, and visualizing the magnetization pattern; A method for producing a lattice, characterized by forming a layer of transparent oxide on a lattice pattern. 2. A method for producing a grating having a phase grating pattern, which comprises writing a desired grating pattern on a magnetic recording medium formed in a thin layer on a substrate using a recording head to form a magnetization pattern according to the pattern; A magnetic colloidal fluid containing iron oxide particles whose particle size is sufficiently small compared to the pitch of the magnetization pattern is applied to the magnetization pattern to visualize the magnetization pattern, and on the visualized lattice pattern, A method for producing a lattice, characterized by forming a thin metal film as a reflective film following the irregularities of the lattice pattern, and forming a transparent oxide layer on the metal film. 3. The method for producing a lattice according to claim 1, wherein the transparent oxide is SiO_2 or InO_2. 4. The method for producing a lattice according to claim 2, wherein the material of the metal film is gold and the transparent oxide is SiO_2 or InO_3. 5. A lattice produced by the method of claim 1 or 2 or 3 or 4.