JP2000283794A - Parts for reflective optical encoder and its manufacturing method - Google Patents

Abstract

(57) [Abstract] An object of the present invention is to provide a component for a reflection type optical encoder. This component is made of a metal or an alloy having a plurality of layers formed of at least two kinds of metals or alloys, and one surface is a light reflecting surface portion, and the one surface is the surface At least one layer of a metal or alloy different from the metal or alloy has a predetermined pattern portion where the surface metal or alloy is not present.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for encoding or pulsing an optical signal or light beam by reflecting light instead of an optical signal encoder such as a slit plate.
The present invention relates to a reflective optical encoder component. Optical encoders are used for various precision machine parts, and such precision machine parts include simple ones such as a digital counter that reads the amount of rotation of a shaft of a drive unit and the amount of horizontal movement. .

[0002]

2. Description of the Related Art As shown in FIG. 8, a conventional reflection type optical encoder forms a black light absorbing portion by applying a predetermined pattern of silver oxide emulsion or the like to a PET film, and forms a metal such as aluminum on the surface thereof. The mainstream is to use an encoder component made by vapor deposition and using the film side as a reflection surface.

[0003] Such encoder parts cannot be used under physical conditions that change the properties of plastic, and the environment in which they are used, that is, the used parts and applications are limited.

[0004] In addition, the plastic surface is susceptible to moisture, and during use, the surface of the plastic becomes fogged, and the pattern cannot be read.

On the surface of a PET film, reflection occurs along with transmission of light, so that the contrast is poor, and the film cannot be adequately used for applications requiring strong contrast.

A component for a reflection type encoder as shown in FIG. 9 manufactured by corroding a reflection surface of a single metal layer to a predetermined pattern to a certain depth is also known. This type of encoder is made of metal only, so it can be used or used for any purpose.However, the part that does not reflect light simply reflects light irregularly because the corroded surface happens to be uneven. Therefore, a strong contrast cannot be obtained for the reflecting surface.

[0007] Further, as can be seen from the fact that metals have different colors depending on the type, in an encoder made of a single metal layer, the portion for reflecting light and the portion for not reflecting light are the same metal. The properties of the wavelengths of the light reflected from these portions are the same or similar, and the reflected light from the portion to be reflected and the reflected light from the portion not to be reflected are difficult to distinguish by the sensor receiving the light. .

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and preferably comprises only a metal or an oxide thereof. The object of the present invention is to provide a reflection type optical encoder component that can obtain a strong contrast by preferably including a portion that absorbs light.

Generally, depending on the magnitude of the amount of reflected light or the presence or absence of reflected light, an optical signal or light beam is reflected at one point to a signal with reflection due to reflection of a portion intended to be reflected or a portion intended to be non-reflected. Encoding or pulsing has been performed as one of the non-reflection signals when light is shining, but sensors that respond specifically to specific wavelengths are possible and multiple types of sensors can be installed in the light receiving unit It is. Thus, if there is a surface containing three or more metals that can give different results with light of different wavelengths, with or without reflection, an optical signal or ray can be emitted at a point in time, depending on the nature of the wavelength of the light.
Reflective optical encoders are possible that can be coded and pulsed to generate signals that exceed species. It is also an object of the present invention to provide components of such a device.

[0010]

Means for Solving the Problems As a result of earnest study, the present inventors have found that the following problems can be solved by the following constitution, and have completed the present invention. That is,

1. It is made of a metal or alloy having a plurality of layers formed of at least two or more metals or alloys, has a light reflecting surface portion, and at least a part of the light reflecting surface portion is a surface intended to reflect light. The surface portion has a predetermined pattern portion in which at least one layer of a metal or alloy different from the surface metal or alloy is exposed and the surface metal or alloy is not present. For reflective optical encoders.

2. The encoder has a portion of a predetermined pattern where the surface metal or alloy is not present where one layer of a metal or alloy different from the surface metal or alloy is exposed, and a metal or metal different from the surface metal or alloy 2. The component for a reflective optical encoder according to the item 1, wherein a metal oxide film for eliminating or reducing light reflection is formed on the exposed portion of the alloy.

3. It has a light reflecting plane portion, at least a part of the plane portion is intended to reflect light, and the structure of the plane portion is such that the surface of the first metal or alloy has a concave portion of a predetermined pattern. And, in the recesses of the predetermined pattern, one or more metals or alloys different from the first metal or alloy and one or more metals or different from the first metal or alloy having a metal oxide film on the surface or A component for a reflective optical encoder, wherein the component has a structure in which at least one selected from the group consisting of alloys exists.

4. A reflective layer of a single metal or alloy, for eliminating or reducing light reflection on a predetermined pattern on the surface of the reflective layer or on a concave surface of a predetermined pattern present on the surface of the reflective layer. A component for a reflective optical encoder, wherein a metal oxide film is formed.

[0015] 5. A resist was applied to the first metal or alloy layer side of a thin metal plate or film having a first metal or alloy layer and a second metal or alloy layer, and only a predetermined pattern of the resist was removed. Forming a resist layer; etching the first metal or alloy with a corrosive liquid to etch the second metal or alloy layer into the surface of the first metal or alloy layer; Exposing the exposed pattern; forming an oxide film of the second metal or alloy on the exposed surface of the second metal or alloy layer to reduce or eliminate light reflection Removing the resist layer; the surface of the first metal or alloy layer including the above steps as a surface to reflect light, and the second metal or alloy The oxide film is a surface that does not reflect light,
A method for manufacturing a component for a reflective optical encoder.

6. A resist is applied to the reflection surface where the first metal or alloy of the metal material is exposed, and a predetermined pattern is formed.
After forming a concave portion by etching a predetermined pattern portion of the reflective surface portion where the resist has escaped, or forming a concave portion without etching, the next step is performed. Transferring, plating a metal different from the metal or alloy on the exposed surface of the metal or alloy from which only the predetermined pattern has been exposed to form a portion of a different metal or alloy; If the portion is not intended to reflect light, a metal oxide film of the different metal or alloy is formed on the surface of the plated portion of the different metal or alloy to reduce or eliminate the reflection of light. Removing the resist layer; polishing only when polishing is necessary;
When the number of times exceeds the number of times, the predetermined pattern is changed to perform the number of times at least once. A component for a reflective optical encoder, wherein at least one of the plurality of types of metals or alloys is a surface that reflects light. Manufacturing method.

In the above description, it is possible to form a resist layer in which only a predetermined pattern of the resist is removed, to etch a specific metal into a predetermined pattern by using a corrosive liquid for the metal, Can be easily performed by those skilled in the art using a well-known photoengraving technique using a stripping solution (stripping solution) suitable for the resist. The formation of a metal oxide film for a specific metal is a technique generally known to those skilled in the art. Hereinafter, the present invention will be described with reference to the drawings.

[0018]

EXAMPLE 1 The last part of the flow chart of FIG. 1 consists of a metal having a nickel layer 1 on the surface and a copper layer 2 on the back side thereof,
FIG. 3 is a cross-sectional view of a reflective optical encoder component having a surface on which a nickel layer is to be reflected.

As shown in FIG. 1, the structure of this part is manufactured by, for example, a) applying a resist to the nickel layer side of a thin metal plate having a nickel layer 1 and a copper layer 2 and removing the resist only in a predetermined pattern. B) etching with a corrosive solution that corrodes only the nickel layer to expose the copper layer 2 at the pattern where the resist has escaped; c) further reducing the copper to a so-called copper oxide treatment, for example. A thin film of copper oxide is formed on the surface of the exposed copper layer by performing a chemical treatment that only reacts; d) removing the resist layer 3 thereafter; In this case, a support layer such as a nickel layer may be present on the back side of the copper layer 2.

Embodiment 2 The reflection at the end of the process chart of FIG. 2 is that a nickel layer 21 on the back side is made of a metal having a copper layer 22 on the surface, and the nickel layer is a surface on which the nickel layer is to be reflected. FIG. 1 is a cross-sectional view of a component for a type optical encoder.

As shown in FIG. 2, the structure of this part is manufactured by, for example, a) applying a resist to a thin metal plate having a nickel layer 21 to form a resist layer 23 from which only a predetermined pattern of the resist has been removed; B) plating a copper layer 22 on the exposed surface of the nickel layer 1 from which only a predetermined pattern of resist has been removed; c) further reacting only with copper, which is called black oxide treatment, on the surface of the plated copper layer 22 A chemical treatment is performed to form a thin film of copper oxide; d) After that, the resist layer 23 is removed;

Embodiment 3 In Embodiment 2, between the steps a) and b), the exposed portion of the nickel layer 31 from which the resist has been removed is etched and then the copper layer 22 is plated, as shown in FIG. In the case where the surface of the copper layer 32 is lower than the surface of the nickel layer 31, or the surface of the copper layer and the first metal 41 are nickel when the second metal 42 is copper as shown in FIG. The surface of the nickel layer can produce a metal of the same level of structure. If necessary, the surface is polished at the end as shown in FIG. 4 and the finished product is further subjected to a different pattern of resist as many times as necessary, so that three or more types of metals are exposed on the reflective surface. Encoder parts can be manufactured. Encoders using such components are:
At the time, it is possible to fabricate a device capable of producing three or more signals instead of two.

Embodiment 4 FIG. 5 shows that the surface of a single metal reflective layer has a portion etched by a predetermined pattern by etching, and the eroded portion reduces the light reflection of the same predetermined pattern. 2 shows a reflection type optical encoder component having a black metal oxide film formed thereon. Such components form a resist with a predetermined pattern missing on the reflective surface of the copper layer,
It can be manufactured by corroding copper with an etchant, performing a process of forming a black metal oxide film, and removing the resist. On the other hand, as shown in FIG. 6, it is also possible to attach a black metal oxide film for reducing light reflection of a predetermined pattern without etching.

Example 5 FIG. 7 shows an encoder component having a first metal layer, a second metal layer, and a third metal layer in which the colors of reflected light are significantly different from each other. FIG. An encoder using such components may also be able to produce a device that can generate three types of signals instead of two at one time. For example, the component of FIG. 7 is obtained by replacing the nickel layer 1 with a thin layer of two kinds of metals in the first embodiment, applying a different pattern of resist after the first etching step, or In the second embodiment, after the nickel layer 21 is formed by plating, another pattern of resist is applied, and another metal layer is formed by plating.

[0025]

[Effects of the present invention] 1) Effects of an encoder component having a plurality of different metal layers a) In the case where the encoder is made of only a metal and does not include a PET film, it is resistant to moisture and fogged regardless of the use environment. No durable. b) Due to the difference in the wavelength of the reflected light due to the different metals, the contrast is improved, and the reading error can be hardly caused by selecting the sensor. c) in some cases, at one point, with reflection, without reflection,
Not only that, it is possible to build an encoder that produces more than two signals. d) In the case of manufacturing an encoder component by etching the surface metal, the precision of the encoder can be increased by making the surface metal layer thin, such as a deposit.

2) Effect of Encoder Component Having Metal Oxide Film a) In addition to weakening reflection due to irregular light reflection, light absorption is positively generated, so that strong contrast can be obtained and reading error can be obtained. Can be eliminated. b) The oxide film has the same properties as metal, and has good durability regardless of the use environment.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a step of manufacturing a specific example of an encoder component of the present invention in a sectional view of the component.

FIG. 2 is an explanatory view showing a step of manufacturing another specific example of the encoder component of the present invention by a cross-sectional view of the component.

FIG. 3 is an explanatory view showing a step of manufacturing another specific example of the encoder component of the present invention in a sectional view of the component.

FIG. 4 is an explanatory view showing a step of manufacturing another specific example of the encoder component of the present invention by a cross-sectional view of the component.

FIG. 5 is a sectional view showing another specific example of the encoder component of the present invention.

FIG. 6 is an explanatory view showing a step of manufacturing another specific example of the encoder component of the present invention by a cross-sectional view of the component.

FIG. 7 is a sectional view showing another specific example of the encoder component of the present invention.

FIG. 8 is a cross-sectional view showing a conventional encoder component including a PET film.

FIG. 9 is a cross-sectional view showing a conventional encoder part made of a single metal.

Claims (6)

[Claims] 1. A light-reflecting surface portion comprising a metal or an alloy having a plurality of layers formed of at least two or more kinds of metals or alloys, and at least a part of the light-reflecting surface portion reflects light. An intended surface, wherein the surface portion has a predetermined pattern portion where the surface metal or alloy is absent and at least one layer of a metal or alloy different from the surface metal or alloy is exposed. A component for a reflective optical encoder. 2. The encoder has a portion of a predetermined pattern in which one surface layer of a metal or alloy different from the surface metal or alloy is exposed and the surface metal or alloy does not exist. The reflective optical encoder part according to claim 1, wherein a metal oxide film for eliminating or reducing light reflection is formed on an exposed portion of a metal or an alloy different from the above. 3. A light-reflecting flat part, at least a part of which is intended to reflect light, wherein the structure of the flat part is such that the surface of the first metal or alloy has a predetermined surface. One or more metals or alloys different from the first metal or alloy in the recesses of the predetermined pattern, and one or more metals or alloys different from the first metal or alloy having a metal oxide film on the surface. A component for a reflective optical encoder, wherein the component has a structure in which at least one selected from the group consisting of at least one kind of metal or alloy exists. 4. A method according to claim 1, further comprising the step of removing light reflection on a predetermined pattern on the surface of the reflection layer or on a concave surface of the predetermined pattern on the surface of the reflection layer. A component for a reflective optical encoder, wherein a metal oxide film for reducing the amount is formed. 5. A predetermined pattern in which a resist is applied to the first metal or alloy layer side of a thin metal plate or film having a first metal or alloy layer and a second metal or alloy layer. Forming only a resist layer from which the resist has escaped; etching with a corrosive solution that corrodes the first metal or alloy to form the second metal or alloy in the surface of the first metal or alloy layer Exposing a layer at the exposed pattern portions of the resist; coating the second metal or alloy oxide film with the exposed second metal or alloy to reduce or eliminate light reflection. Performing a process of forming on the surface of the layer; removing the resist layer thereafter; making the surface of the first metal or alloy layer the surface that is to reflect light; Reflection-type optical encoder that uses a metal or alloy oxide film as a surface that does not reflect light Method of manufacturing over parts for. 6. A resist is applied to the reflection surface portion where the first metal or alloy of the metal material is exposed to form a resist layer in which only a predetermined pattern of the resist is removed; After the concave portion is formed by etching the predetermined pattern portion where the resist has been removed, or without etching, the process proceeds to the next step without forming the concave portion, and only the predetermined pattern is exposed on the exposed metal or alloy surface where the resist has been removed. Forming a portion of a different metal or alloy by plating a metal different from the metal or alloy; reducing the reflection of light if the portion of the different metal or alloy is not intended to reflect light In order to eliminate or eliminate, a process of forming a dark oxide film of the different metal or alloy on the surface of the plated portion of the different metal or alloy is performed; the resist layer is removed; polishing is required. Only if When the polishing process is performed, if the above steps are performed more than once, the predetermined pattern is changed and the polishing is performed one or more times. And
A method for manufacturing a component for a reflective optical encoder.