WO2019093276A1 - Code plate of reflective-type optical encoder - Google Patents

Code plate of reflective-type optical encoder Download PDF

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Publication number
WO2019093276A1
WO2019093276A1 PCT/JP2018/041020 JP2018041020W WO2019093276A1 WO 2019093276 A1 WO2019093276 A1 WO 2019093276A1 JP 2018041020 W JP2018041020 W JP 2018041020W WO 2019093276 A1 WO2019093276 A1 WO 2019093276A1
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light
reflective
layer
optical encoder
reflectance
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PCT/JP2018/041020
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French (fr)
Japanese (ja)
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大悟 青木
佐藤　清
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アルプスアルパイン株式会社
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Publication of WO2019093276A1 publication Critical patent/WO2019093276A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
    • G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
    • G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
    • G01D5/347—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells using displacement encoding scales

Definitions

  • the present invention relates to a code plate of a reflective optical encoder.
  • a reflective optical encoder includes a code plate, a light source such as an LED, and a light detector to obtain position information.
  • the code plate has low reflection areas and high reflection areas alternately arranged. The reflectance of light in the high reflection area is higher than the reflectance of light in the low reflection area.
  • the code plate is irradiated with light from a light source, and the reflected light is detected by a light detector.
  • the light reflected by the code plate is streaked in the light detector since the low reflection areas and the high reflection areas are alternately arranged with each other and the light reflectance in the high reflection areas is higher than the light reflectance in the low reflection areas.
  • Generate an image of The phase of the striped image changes as the position of the code plate moves in the measurement direction.
  • the phase change of the striped image is detected by the light detector, and based on the detected phase change of the striped image, displacement information of the position of the code plate is processed to obtain position information.
  • the optical encoder reflector described in Patent Document 1 includes a substrate formed of a glass material, a light reflection layer (light reflection portion) provided on a part of the surface of the substrate and capable of reflecting light, and the substrate And a light absorbing layer (light absorbing portion) which absorbs light incident on a region of the substrate which is out of the light reflecting portion.
  • the light reflection layer is formed using aluminum, an aluminum alloy, or the like.
  • the reflector for an optical encoder described in Patent Document 1 requires a complicated process such as providing a light reflection layer and a light absorption layer on both the front and back sides of the substrate.
  • the present invention is for solving the above-mentioned conventional problems, and is excellent in corrosion resistance while securing a sufficient difference between the light reflectance in the high reflection region and the light reflectance in the low reflection region.
  • An object of the present invention is to provide a code plate of a reflective optical encoder which can be manufactured by a simple process.
  • the code plate of the reflective optical encoder of the present invention is a code plate of a reflective optical encoder in which high reflective regions and low reflective regions are alternately arranged in an underlayer,
  • the reflectance of light in the high reflection region is higher than the reflectance of light in the low reflection region, and is provided on the underlayer in the high reflection region, and is characterized by including a reflection layer containing ruthenium.
  • the film thickness of the reflective layer is preferably 20 nm or more and 500 nm or less.
  • the code plate of the reflective optical encoder of the present invention it is preferable to provide a protective layer provided on the reflective layer and the underlayer in the low reflective area to protect ruthenium.
  • the material of this protective layer is preferably silicon dioxide.
  • the protective layer preferably has a thickness of 0 nm or more and 60 nm or less, or 200 nm or more and 340 nm or less.
  • the present invention it is excellent in corrosion resistance while sufficiently securing the difference between the light reflectance in the high reflection region and the light reflectance in the low reflection region, and it is possible to manufacture it by a simple process. It is possible to provide a code board for a rotary encoder.
  • FIG.1 and FIG.2 is a schematic diagram which shows the reflection type optical encoder in which the code board of the reflection type optical encoder concerning this embodiment was used.
  • FIG. 2 is a schematic view when the reflective optical encoder is viewed in the direction of arrow A1 shown in FIG.
  • the reflective optical encoder 10 shown in FIGS. 1 and 2 includes a code plate 100 and a detection head 200.
  • the code plate 100 is disposed below and the detection head 200 is disposed above, and the code plate 100 and the detection head 200 face each other in the vertical direction.
  • the detection head 200 includes a light source 210, a light detector 220, and a detection substrate 230.
  • the light source 210 and the light detector 220 are provided on the lower surface of the detection substrate 230.
  • the light source 210 is, for example, a point light source LED which has a small light emitting surface and emits light of a single wavelength ⁇ . In the present embodiment, it is assumed that the light source 210 emits infrared light having a wavelength of about 850 nanometers (nm).
  • the light source 210 may include a collimator lens that collimates the emitted light.
  • the photodetector 220 is, for example, composed of a plurality of photodiodes arranged in a matrix at predetermined intervals.
  • the photodetector 220 may include at least one of a peripheral circuit that converts a signal output from the plurality of photodiodes and an amplification circuit.
  • FIG. 3 is a schematic cross-sectional view showing the configuration of the code plate 100 of the reflective optical encoder according to the present embodiment. As shown in FIG. 3, the code plate 100 has an underlayer 110, a reflective layer 120, and a protective layer 130.
  • the base layer 110 glass is used, for example. Specifically, for example, quartz glass and borosilicate glass are used for the base layer 110.
  • the thickness t1 (FIG. 3) of the base layer 110 is not particularly limited, and is, for example, about 0.5 millimeter (mm) or more and about 1 mm or less.
  • the reflective layer 120 is provided on the underlayer 110 and contains ruthenium (Ru) having the property of reflecting the light emitted from the light source 210.
  • the phrase “the reflective layer 120 contains ruthenium” simply includes the case where the reflective layer 120 contains ruthenium or an alloy of ruthenium.
  • platinum group elements such as rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), or an alloy thereof can be used. It can also be used.
  • ruthenium (Ru) is preferable because of its excellent availability stability and ease.
  • the reflective layer 120 has a thickness t2 (FIG. 3) sufficient to reflect the light emitted from the light source 210.
  • the thickness t2 will be described later with reference to FIG.
  • the reflective layer 120 is formed on the surface of the base layer 110 by sputtering, vapor deposition, or the like.
  • a layer containing ruthenium is formed on the surface of the underlayer 110 by sputtering, and a resist is formed on the layer containing ruthenium. .
  • the resist is exposed and developed and patterned, and then the ruthenium containing layer is etched. Thereafter, when the resist is peeled off, a patterned ruthenium-containing reflective layer 120 is formed on the surface of the underlayer 110.
  • the protective layer 130 is provided on the underlayer 110 and the reflective layer 120 to protect the ruthenium contained in the reflective layer 120.
  • Examples of the material of the protective layer 130 include silicon dioxide (SiO 2).
  • the protective layer 130 has a thickness t3 (FIG. 3) to the extent that the ruthenium contained in the reflective layer 120 can be protected.
  • the protective layer 130 is formed on the surface of the base layer 110 and the reflective layer 120 by sputtering, vapor deposition, or the like.
  • the code plate 100 has a high reflection area 101 and a low reflection area 102.
  • a reflective layer 120 and a protective layer 130 are provided in the high reflective region 101.
  • the low reflection region 102 only the protective layer 130 is provided, and the reflective layer 120 is not provided.
  • the reflectance of the reflective layer 120 to the light irradiated from the light source 210 is higher than the reflectance of the protective layer 130 to the light irradiated from the light source 210. Therefore, the reflectance of light in the high reflection area 101 is higher than the reflectance of light in the low reflection area 102.
  • the high reflection areas 101 and the low reflection areas 102 are alternately arranged. As described above, the reflectance of light in the high reflection area 101 is higher than the reflectance of light in the low reflection area 102. Therefore, the light emitted from the light source 210 generates a striped image in the photodetector 220 of the detection head 200 provided to face the code plate 100.
  • the striped image moves in the light detector 220.
  • the light amount of the image of the light (reflected light) reflected by the code plate 100 is detected by the light detector 220.
  • the reflective optical encoder 10 can acquire position information.
  • FIG. 4 (1) Configuration A (a configuration corresponding to the high reflective region 101) in which glass is used for the underlayer 110, the reflective layer 120 is formed of ruthenium, and the protective layer 130 is formed of silicon dioxide (Example 1) , 2), and (2) Reflectivity in the simulation for the configuration B (configuration corresponding to the low reflection region 102) (Example 3) in which only the protective layer composed of silicon dioxide is formed on the underlayer 110 composed of glass Is a graph showing the change of.
  • the lines L1 and L2 in the graph show the change in reflectance of the above configuration A, and the line L3 shows the change in reflectance of the above configuration B.
  • line L1 shows the case where the film thickness of the reflective layer 120 is 50 nm (Example 1)
  • line L2 shows the case where the film thickness of the reflective layer 120 is 100 nm (Example 2).
  • the horizontal axis of this graph indicates the film thickness (unit nm) of the layer made of silicon dioxide, and the vertical axis on the left, "Reflectivity [Ru] [%]” indicates the reflectance (unit%) for configuration A of lines L1 and L2
  • the right vertical axis “Reflectivity [SiO 2 ] [%]” indicates the reflectance (unit%) for the configuration B of the line L3.
  • n and k are the refractive index n and the extinction coefficient k in the complex refractive index m shown by the following equation (1).
  • m n-ik (1) (i is an imaginary number)
  • Example 1 (configuration corresponding to line L1): base layer / reflection layer (Ru 50 nm) / protective layer (2)
  • Example 2 (configuration corresponding to line L2): base layer / reflection layer (Ru 100 nm) / Protective layer (3)
  • Protective layer (common to Examples 1 to 3): Silicon dioxide (SiO 2 ), film
  • the reflectance in the above-mentioned configuration B (Example 3) corresponding to the low reflection region 102 is somewhat small near the film thickness of 150 nm of SiO 2 , but overall it is SiO
  • the change with respect to the change in the film thickness of 2 is relatively small, and remains within the range of about 7.8 to 8.3%.
  • the reflectance in the above configuration A corresponding to the high reflection region 101 changes in accordance with the change in the film thickness of SiO 2 .
  • the difference from the reflectance shown in the line L3 (Example 3) is 50 or more.
  • the difference with the reflectance shown in the line L3 (Example 3) is 50 or more It has become.
  • a code plate of a reflective optical encoder in order to detect a striped image generated by reflected light with relatively high accuracy, the reflectance of light in a high reflection area and a low reflection area A difference of 50 or more with the light reflectance at is required.
  • the difference between the reflectance of light in the high reflection region 101 and the reflectance of light in the low reflection region 102 can be made 50 or more in a predetermined range.
  • the thickness of the reflective layer 120 is preferably 20 nm or more and 500 nm or less in the case of the above configuration A, considering the uniformity of the film, adhesion, and the occurrence of cracks when stress occurs.
  • the thickness is more preferably 30 nm or more and 200 nm or less, and still more preferably 40 nm or more and 100 nm or less.
  • FIG. 5 is a graph showing a change in reflectance (%) in a simulation when a ruthenium film is irradiated with light having a wavelength of 850 nm.
  • the horizontal axis of FIG. 5 is a film thickness (unit nm) of ruthenium, which is a structure in which ruthenium is formed on a glass substrate.
  • the reflectance of the ruthenium film exceeds 60% at a film thickness of 20 nm, peaks at 40 nm, and maintains a high reflectance of over 65% after exceeding 40 nm. Therefore, it is understood that the film thickness of the reflective layer 120 using ruthenium is preferably 20 nm or more, more preferably 30 nm or more, and further preferably 40 nm or more.
  • FIG. 6 is a schematic cross-sectional view showing the configuration of the code plate 300 of the reflective optical encoder according to the comparative example.
  • FIG. 7 is a photograph showing an enlarged part of the code plate 100 according to the example of the present embodiment, wherein (a) shows the state before the endurance test, and (b) shows the state after the endurance test It is a photograph.
  • FIG. 8 is a photograph showing an enlarged part of the code plate 300 according to the comparative example, wherein (a) shows a state before the endurance test, and (b) shows a state after the endurance test.
  • the endurance test was carried out by placing for 24 hours in a thermostat at a temperature of 85 ° C. and a humidity of 85%.
  • the configuration of the first embodiment that is, the configuration in which the film thickness of the reflective layer 120 is 50 nm in the high reflection region 101, is used in the low reflection region 102. It is set as the structure (structure which formed only the protective layer which consists of silicon dioxides on a base layer). Further, the protective layer 130 has a thickness of 270 nm.
  • cord board 300 in the comparative example shown to FIG. 8 (a), (b) has the base layer 310, the reflection layer 320, the protective layer 330, and the coating layer 340, as shown in FIG.
  • the composition of each layer is as follows.
  • Reflective layer 320 Silver indium tin (AgInSn), film thickness 100 nm
  • Protective layer 330 aluminum oxide (Al 2 O 3 ), film thickness 20 nm
  • Coating layer 340 Silicon dioxide (SiO 2 ), film thickness 100 nm
  • the code plate 300 has a high reflection area 301 and a low reflection area 302.
  • a reflective layer 320, a protective layer 330, and a cover layer 340 are provided in the highly reflective region 301.
  • the low reflective region 302 is provided with the protective layer 330 and the covering layer 340, and the reflective layer 320 is not provided.
  • the reflectance of the reflective layer 320 to the light irradiated from the light source 210 is higher than the reflectance of the protective layer 330 to the light irradiated from the light source 210 and the reflectance of the covering layer 340 to the light irradiated from the light source 210 . Therefore, the reflectance of light in the high reflection area 301 is higher than the reflectance of light in the low reflection area 302.
  • FIG. 7 (a), (b) is compared with each other, although a black-spot-like refuse is slightly seen after an endurance test, corrosion is not recognized in visual observation and it has maintained the favorable state. That is, the striped image generated by the light reflected by each of the high reflection area and the low reflection area clearly appears, and the striped image can be detected with high accuracy. Therefore, according to the structure which concerns on an Example, it turns out that it is equipped with sufficient moisture resistance (durability) as a code
  • FIGS. 8A and 8B are compared with each other, it can be seen that a large number of black bubbles appear in at least the high reflection area 101 visually, and the corrosion progresses to a considerable extent.
  • the degree of this corrosion is clearly recognized also by comparing FIG. 7 (b) with FIG. 8 (b).
  • FIG. 8B if the change due to corrosion as shown in FIG. 8B occurs in the high reflection area of the code plate, the light reflectance in the high reflection area is lowered, so the light reflectance in the low reflection area And the difference between For this reason, it becomes difficult to detect a striped image generated by light respectively reflected in the high reflection area and the low reflection area with high accuracy.
  • the code plate of the reflective optical encoder according to the present invention can sufficiently ensure the difference between the light reflectance in the high reflection region and the light reflectance in the low reflection region, and is corrosion resistant. It is useful in that it can be manufactured by a simple process.

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Abstract

In a code plate of a reflective-type optical encoder which has excellent corrosion resistance and which can be manufactured using a simple process while adequately ensuring a difference between the reflection coefficient of light in high reflection regions and the reflection coefficient of light in low reflection regions, the high reflection regions and the low reflection regions are disposed alternately on an underlayer, the reflection coefficient of light in the high reflection regions is higher than the reflection coefficient of light in the low reflection regions, and a reflective layer containing ruthenium is provided on the underlayer in the high reflection regions.

Description

反射型光学式エンコーダのコード板Code plate of reflective optical encoder
　本発明は、反射型光学式エンコーダのコード板に関する。 The present invention relates to a code plate of a reflective optical encoder.
　一般に、反射型光学式エンコーダは、コード板と、ＬＥＤなどの光源と、光検出器とを備え、位置情報を取得する。コード板は、互いに交互に配置された低反射領域と高反射領域とを有する。高反射領域における光の反射率は、低反射領域における光の反射率よりも高い。コード板には光源からの光が照射され、その反射光は光検出器で検出される。 In general, a reflective optical encoder includes a code plate, a light source such as an LED, and a light detector to obtain position information. The code plate has low reflection areas and high reflection areas alternately arranged. The reflectance of light in the high reflection area is higher than the reflectance of light in the low reflection area. The code plate is irradiated with light from a light source, and the reflected light is detected by a light detector.
　低反射領域及び高反射領域が互いに交互に配置され、高反射領域における光の反射率が低反射領域における光の反射率よりも高いため、コード板において反射した光は、光検出器において縞状の像を生成する。縞状の像の位相は、コード板の位置が測長方向に移動することによって変化する。この縞状の像の位相変化は光検出器によって検出され、検出された縞状の像の位相変化に基づいてコード板の位置の変位情報が処理され、位置情報が取得される。 The light reflected by the code plate is streaked in the light detector since the low reflection areas and the high reflection areas are alternately arranged with each other and the light reflectance in the high reflection areas is higher than the light reflectance in the low reflection areas. Generate an image of The phase of the striped image changes as the position of the code plate moves in the measurement direction. The phase change of the striped image is detected by the light detector, and based on the detected phase change of the striped image, displacement information of the position of the code plate is processed to obtain position information.
　特許文献１に記載の光学式エンコーダ用反射板は、硝材を用いて形成された基板と、基板の表面の一部に設けられ、光を反射可能な光反射層（光反射部）と、基板に設けられ、基板のうち光反射部から外れた領域に入射する光を吸収する光吸収層（光吸収部）とを備える。光反射層は、アルミニウムやアルミニウム合金などを用いて形成される。これにより、光反射特性の低下を低減することができる光学式エンコーダ用反射板を提供することができるとしている。 The optical encoder reflector described in Patent Document 1 includes a substrate formed of a glass material, a light reflection layer (light reflection portion) provided on a part of the surface of the substrate and capable of reflecting light, and the substrate And a light absorbing layer (light absorbing portion) which absorbs light incident on a region of the substrate which is out of the light reflecting portion. The light reflection layer is formed using aluminum, an aluminum alloy, or the like. As a result, it is possible to provide a reflector for an optical encoder that can reduce the decrease in light reflection characteristics.
特開２０１２－６３２０１号公報JP 2012-63201 A
　しかし、特許文献１の光学式エンコーダ用反射板の光反射層に用いるアルミニウムは、高湿度環境に長時間放置すると腐食されやすく、反射型光学式エンコーダのコード板に用いるには耐湿性が十分とは言えなかった。また、特許文献１に記載の光学式エンコーダ用反射板は、光反射層と光吸収層を基板の表裏両面に設けるなど複雑なプロセスが必要であった。 However, aluminum used for the light reflection layer of the reflector for optical encoder of Patent Document 1 is easily corroded when left in a high humidity environment for a long time, and is sufficiently moisture resistant for use in the code plate of the reflective optical encoder. I could not say. In addition, the reflector for an optical encoder described in Patent Document 1 requires a complicated process such as providing a light reflection layer and a light absorption layer on both the front and back sides of the substrate.
　本発明は、上記従来の課題を解決するためのものであり、高反射領域における光の反射率と、低反射領域における光の反射率との差を十分確保しつつ、耐腐食性にすぐれ、シンプルなプロセスで製造することができる反射型光学式エンコーダのコード板を提供することを目的とする。 The present invention is for solving the above-mentioned conventional problems, and is excellent in corrosion resistance while securing a sufficient difference between the light reflectance in the high reflection region and the light reflectance in the low reflection region. An object of the present invention is to provide a code plate of a reflective optical encoder which can be manufactured by a simple process.
　上記課題を解決するために、本発明の反射型光学式エンコーダのコード板は、高反射領域と低反射領域とが下地層に交互に配置された反射型光学式エンコーダのコード板であって、高反射領域における光の反射率は、低反射領域における光の反射率よりも高く、高反射領域における下地層の上に設けられ、ルテニウムを含有する反射層を備えたことを特徴としている。
　これにより、高反射領域における光の反射率と、低反射領域における光の反射率との差を十分確保でき、さらに、耐腐食性にすぐれ、シンプルなプロセスで製造することができる。 In order to solve the above problems, the code plate of the reflective optical encoder of the present invention is a code plate of a reflective optical encoder in which high reflective regions and low reflective regions are alternately arranged in an underlayer, The reflectance of light in the high reflection region is higher than the reflectance of light in the low reflection region, and is provided on the underlayer in the high reflection region, and is characterized by including a reflection layer containing ruthenium.
As a result, the difference between the light reflectance in the high reflection area and the light reflectance in the low reflection area can be sufficiently ensured, and further, the corrosion resistance is excellent and the manufacturing can be performed by a simple process.
　本発明の反射型光学式エンコーダのコード板において、反射層の膜厚は２０ｎｍ以上５００ｎｍ以下であることが好ましい。
　これにより、高反射領域における光の反射率と、低反射領域における光の反射率との差を十分確保でき、コード板上で反射した光によって生成された縞状の像を高い精度で検出することが可能となる。 In the code plate of the reflective optical encoder of the present invention, the film thickness of the reflective layer is preferably 20 nm or more and 500 nm or less.
As a result, the difference between the light reflectance in the high reflection area and the light reflectance in the low reflection area can be sufficiently ensured, and a stripe-like image generated by the light reflected on the code plate can be detected with high accuracy. It becomes possible.
　本発明の反射型光学式エンコーダのコード板において、反射層と低反射領域における下地層との上に設けられ、ルテニウムを保護する保護層を備えることが好ましい。この保護層の材料は二酸化ケイ素であることが好ましい。
　これにより、例えばコード板の製造工程での、ガラス基板からの切り出し加工や、洗浄時の薬品による腐食変色を防止できる。また、コード板の洗浄残渣を拭き取る工程やその後の取扱い時において表面に触れてしまうことで、キズ、剥がれが生じることを防止することができる。 In the code plate of the reflective optical encoder of the present invention, it is preferable to provide a protective layer provided on the reflective layer and the underlayer in the low reflective area to protect ruthenium. The material of this protective layer is preferably silicon dioxide.
Thereby, it is possible to prevent, for example, cutting out from the glass substrate in the process of manufacturing the code plate, and corrosion and discoloration due to chemicals during cleaning. Moreover, it can prevent that a flaw and peeling arise by touching the surface in the process of wiping off the washing | cleaning residue of a code | cord board, and subsequent handling.
　本発明の反射型光学式エンコーダのコード板において、保護層の膜厚は、０ｎｍ以上６０ｎｍ以下、又は、２００ｎｍ以上３４０ｎｍ以下であることが好ましい。
　保護層の膜厚を最適な範囲にすることで、高反射領域における光の反射率と、低反射領域における光の反射率との差を所望の範囲にすることができ、これにより、コード板上で反射した光によって生成された縞状の像を高い精度で検出することが可能となる。 In the code plate of the reflective optical encoder of the present invention, the protective layer preferably has a thickness of 0 nm or more and 60 nm or less, or 200 nm or more and 340 nm or less.
By setting the film thickness of the protective layer in the optimum range, it is possible to make the difference between the light reflectance in the high reflection region and the light reflectance in the low reflection region into a desired range, thereby making the code plate It is possible to detect with high accuracy the striped image produced by the light reflected above.
　本発明によると、高反射領域における光の反射率と、低反射領域における光の反射率との差を十分確保しつつ、耐腐食性にすぐれ、シンプルなプロセスで製造することができる反射型光学式エンコーダのコード板を提供することができる。 According to the present invention, it is excellent in corrosion resistance while sufficiently securing the difference between the light reflectance in the high reflection region and the light reflectance in the low reflection region, and it is possible to manufacture it by a simple process. It is possible to provide a code board for a rotary encoder.
本発明の実施形態に係る反射型光学式エンコーダを示す模式図である。It is a schematic diagram which shows the reflection type optical encoder which concerns on embodiment of this invention. 本発明の実施形態に係る反射型光学式エンコーダを示す模式図である。It is a schematic diagram which shows the reflection type optical encoder which concerns on embodiment of this invention. 本発明の実施形態に係る反射型光学式エンコーダのコード板の構成を示す模式的断面図である。It is a typical sectional view showing the composition of the code board of the reflective optical encoder concerning the embodiment of the present invention. 本発明の実施形態における各層の膜厚と反射率の関係を示すグラフである。It is a graph which shows the relationship between the film thickness of each layer in embodiment of this invention, and a reflectance. ルテニウム膜に対して波長８５０ｎｍの光を照射したときのシミュレーションにおける反射率（％）の変化を示すグラフである。It is a graph which shows the change of the reflectance (%) in simulation when light with a wavelength of 850 nm is irradiated with respect to a ruthenium film. 比較例に係る反射型光学式エンコーダのコード板の構成を示す模式的断面図である。It is a typical sectional view showing composition of a code board of a reflective type optical encoder concerning a comparative example. 実施例に係るコード板の一部を拡大して示す写真であって、（ａ）は耐久試験前の状態を示し、（ｂ）は耐久試験後の状態を示す写真である。It is a photograph which expands and shows a part of code board concerning an example, and (a) shows the state before a endurance test, and (b) is a photograph which shows the state after an endurance test. 比較例に係るコード板の一部を拡大して示す写真であって、（ａ）は耐久試験前の状態を示し、（ｂ）は耐久試験後の状態を示す写真である。It is a photograph which expands and shows a part of code board concerning a comparative example, and (a) shows the state before a endurance test, and (b) is a photograph which shows the state after an endurance test.
　以下、本発明の実施形態に係る反射型光学式エンコーダのコード板について図面を参照しつつ詳しく説明する。図１及び図２は、本実施形態に係る反射型光学式エンコーダのコード板が用いられた反射型光学式エンコーダを示す模式図である。図２は、図１に示す矢印Ａ１の方向に反射型光学式エンコーダを眺めたときの模式図である。 Hereinafter, a code plate of a reflective optical encoder according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG.1 and FIG.2 is a schematic diagram which shows the reflection type optical encoder in which the code board of the reflection type optical encoder concerning this embodiment was used. FIG. 2 is a schematic view when the reflective optical encoder is viewed in the direction of arrow A1 shown in FIG.
　図１及び図２に示す反射型光学式エンコーダ１０は、コード板１００と、検出ヘッド２００とを備える。反射型光学式エンコーダ１０では、コード板１００が下に配置され、検出ヘッド２００が上に配置されており、コード板１００と検出ヘッド２００は、上下方向において互いに対向している。 The reflective optical encoder 10 shown in FIGS. 1 and 2 includes a code plate 100 and a detection head 200. In the reflective optical encoder 10, the code plate 100 is disposed below and the detection head 200 is disposed above, and the code plate 100 and the detection head 200 face each other in the vertical direction.
　図１及び図２に示すように、検出ヘッド２００は、光源２１０と、光検出器２２０と、検出基板２３０とを有する。光源２１０と光検出器２２０は、検出基板２３０の下面に設けられている。 As shown in FIGS. 1 and 2, the detection head 200 includes a light source 210, a light detector 220, and a detection substrate 230. The light source 210 and the light detector 220 are provided on the lower surface of the detection substrate 230.
　光源２１０は、例えば、発光面が小さく単一波長λの光を照射する点光源ＬＥＤである。本実施形態においては、光源２１０が約８５０ナノメートル（ｎｍ）程度の波長の赤外光を照射する場合を考える。光源２１０は、放出された光を平行光とするコリメータレンズを含んでいてもよい。 The light source 210 is, for example, a point light source LED which has a small light emitting surface and emits light of a single wavelength λ. In the present embodiment, it is assumed that the light source 210 emits infrared light having a wavelength of about 850 nanometers (nm). The light source 210 may include a collimator lens that collimates the emitted light.
　光検出器２２０は、例えば、所定の間隔でマトリックス状に並べられた複数のフォトダイオードで構成される。光検出器２２０は、上記複数のフォトダイオードが出力する信号を変換する周辺回路、及び、増幅回路の少なくともいずれかを含んでもよい。 The photodetector 220 is, for example, composed of a plurality of photodiodes arranged in a matrix at predetermined intervals. The photodetector 220 may include at least one of a peripheral circuit that converts a signal output from the plurality of photodiodes and an amplification circuit.
　図３は、本実施形態に係る反射型光学式エンコーダのコード板１００の構成を示す模式的断面図である。図３に示すように、コード板１００は、下地層１１０と、反射層１２０と、保護層１３０とを有する。 FIG. 3 is a schematic cross-sectional view showing the configuration of the code plate 100 of the reflective optical encoder according to the present embodiment. As shown in FIG. 3, the code plate 100 has an underlayer 110, a reflective layer 120, and a protective layer 130.
　下地層１１０には、例えばガラスが用いられる。具体的には、下地層１１０には、例えば、石英ガラス及びホウケイ酸ガラスなどが用いられる。下地層１１０の厚さｔ１（図３）は、特には限定されず、例えば０．５ミリメートル（ｍｍ）以上、１ｍｍ以下程度である。 For the base layer 110, glass is used, for example. Specifically, for example, quartz glass and borosilicate glass are used for the base layer 110. The thickness t1 (FIG. 3) of the base layer 110 is not particularly limited, and is, for example, about 0.5 millimeter (mm) or more and about 1 mm or less.
　反射層１２０は、下地層１１０の上に設けられ、光源２１０から照射された光を反射する性質を有するルテニウム（Ｒｕ）を含有する。なお、本願明細書において、単に「反射層１２０がルテニウムを含有する」という場合には、反射層１２０がルテニウム又はルテニウムの合金を含有する場合が含まれる。また、反射層１２０の材料としては、ルテニウムのほか、白金族元素である、ロジウム（Ｒｈ）、パラジウム（Ｐｄ）、オスミウム（Ｏｓ）、イリジウム（Ｉｒ）、白金（Ｐｔ）、又はこれらの合金を用いることもできる。これらの白金族元素の中でも、ルテニウム（Ｒｕ）が入手の安定性および容易性に優れ、好ましい。 The reflective layer 120 is provided on the underlayer 110 and contains ruthenium (Ru) having the property of reflecting the light emitted from the light source 210. In the present specification, the phrase “the reflective layer 120 contains ruthenium” simply includes the case where the reflective layer 120 contains ruthenium or an alloy of ruthenium. Moreover, as a material of the reflective layer 120, in addition to ruthenium, platinum group elements such as rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), or an alloy thereof can be used. It can also be used. Among these platinum group elements, ruthenium (Ru) is preferable because of its excellent availability stability and ease.
　反射層１２０は、光源２１０から照射された光を反射することができる程度の厚さｔ２（図３）を有している。この厚さｔ２については図４を用いて後述する。 The reflective layer 120 has a thickness t2 (FIG. 3) sufficient to reflect the light emitted from the light source 210. The thickness t2 will be described later with reference to FIG.
　反射層１２０は、スパッタや蒸着などにより下地層１１０の表面上に形成される。反射層１２０をスパッタにより下地層１１０の表面上に形成する場合には、例えばルテニウムを含有する層をスパッタにより下地層１１０の表面上に形成し、ルテニウムを含有する層の上にレジストを形成する。つづいて、レジストを露光及び現像してパターニングした後、ルテニウムを含有する層をエッチングする。その後、レジストを剥離すると、パターニングされたルテニウムを含有する反射層１２０が下地層１１０の表面上に形成される。 The reflective layer 120 is formed on the surface of the base layer 110 by sputtering, vapor deposition, or the like. When the reflective layer 120 is formed on the surface of the underlayer 110 by sputtering, for example, a layer containing ruthenium is formed on the surface of the underlayer 110 by sputtering, and a resist is formed on the layer containing ruthenium. . Subsequently, the resist is exposed and developed and patterned, and then the ruthenium containing layer is etched. Thereafter, when the resist is peeled off, a patterned ruthenium-containing reflective layer 120 is formed on the surface of the underlayer 110.
　保護層１３０は、下地層１１０及び反射層１２０の上に設けられ、反射層１２０が含有するルテニウムを保護する。保護層１３０の材料としては、例えば二酸化ケイ素（ＳｉＯ２）が挙げられる。保護層１３０は、反射層１２０が含有するルテニウムを保護することができる程度の厚さｔ３（図３）を有している。また、保護層１３０は、反射層１２０が有する反射性よりも低い反射性を有することが望ましい。保護層１３０は、スパッタや蒸着などにより下地層１１０及び反射層１２０の表面上に形成される。 The protective layer 130 is provided on the underlayer 110 and the reflective layer 120 to protect the ruthenium contained in the reflective layer 120. Examples of the material of the protective layer 130 include silicon dioxide (SiO 2). The protective layer 130 has a thickness t3 (FIG. 3) to the extent that the ruthenium contained in the reflective layer 120 can be protected. In addition, it is desirable that the protective layer 130 have reflectivity lower than that of the reflective layer 120. The protective layer 130 is formed on the surface of the base layer 110 and the reflective layer 120 by sputtering, vapor deposition, or the like.
　図３に示すように、コード板１００は、高反射領域１０１と、低反射領域１０２とを有する。高反射領域１０１には、反射層１２０と、保護層１３０とが設けられている。低反射領域１０２には、保護層１３０のみが設けられており、反射層１２０が設けられていない。光源２１０から照射された光に対する反射層１２０の反射率は、光源２１０から照射された光に対する保護層１３０の反射率よりも高い。そのため、高反射領域１０１における光の反射率は、低反射領域１０２における光の反射率よりも高くなる。 As shown in FIG. 3, the code plate 100 has a high reflection area 101 and a low reflection area 102. A reflective layer 120 and a protective layer 130 are provided in the high reflective region 101. In the low reflection region 102, only the protective layer 130 is provided, and the reflective layer 120 is not provided. The reflectance of the reflective layer 120 to the light irradiated from the light source 210 is higher than the reflectance of the protective layer 130 to the light irradiated from the light source 210. Therefore, the reflectance of light in the high reflection area 101 is higher than the reflectance of light in the low reflection area 102.
　図１～図３に示すように、コード板１００において、高反射領域１０１と低反射領域１０２とは、互いに交互に配置されている。前述したように、高反射領域１０１における光の反射率は、低反射領域１０２における光の反射率よりも高い。そのため、光源２１０から照射された光は、コード板１００と対向して設けられた検出ヘッド２００の光検出器２２０において縞状の像を生成する。 As shown in FIGS. 1 to 3, in the code plate 100, the high reflection areas 101 and the low reflection areas 102 are alternately arranged. As described above, the reflectance of light in the high reflection area 101 is higher than the reflectance of light in the low reflection area 102. Therefore, the light emitted from the light source 210 generates a striped image in the photodetector 220 of the detection head 200 provided to face the code plate 100.
　コード板１００が検出ヘッド２００に対して図１に示すＸ１－Ｘ２方向（測長方向）に移動すると、縞状の像は、光検出器２２０において移動する。これにより、コード板１００において反射された光（反射光）の像の光量が光検出器２２０によって検出される。そして、反射型光学式エンコーダ１０は、位置情報を取得することができる。 When the code plate 100 moves in the X1-X2 direction (length measurement direction) shown in FIG. 1 with respect to the detection head 200, the striped image moves in the light detector 220. Thus, the light amount of the image of the light (reflected light) reflected by the code plate 100 is detected by the light detector 220. Then, the reflective optical encoder 10 can acquire position information.
　次に、各層の膜厚と反射率に関して実施例を用いて説明する。図４は、（１）下地層１１０にガラスを用い、反射層１２０をルテニウムで形成するとともに、保護層１３０を二酸化ケイ素で形成した構成Ａ（高反射領域１０１に対応する構成）（実施例１、２）、及び、（２）ガラスからなる下地層１１０上に二酸化ケイ素からなる保護層のみを形成した構成Ｂ（低反射領域１０２に対応する構成）（実施例３）についてのシミュレーションにおける反射率の変化を示すグラフである。グラフ中の線Ｌ１、Ｌ２は上記構成Ａの反射率変化を示し、線Ｌ３は上記構成Ｂの反射率変化を示している。さらに、線Ｌ１は反射層１２０の膜厚が５０ｎｍの場合（実施例１）、線Ｌ２は反射層１２０の膜厚が１００ｎｍの場合（実施例２）を示している。このグラフの横軸は二酸化ケイ素からなる層の膜厚（単位ｎｍ）を示し、左側の縦軸「Ｒｅｆｌｅｃｔｉｖｉｔｙ［Ｒｕ］［％］」は線Ｌ１、Ｌ２の構成Ａについての反射率（単位％）を示し、右側の縦軸「Ｒｅｆｌｅｃｔｉｖｉｔｙ［ＳｉＯ２］［％］」は線Ｌ３の構成Ｂについての反射率（単位％）を示している。 Next, the film thickness and reflectance of each layer will be described using examples. FIG. 4: (1) Configuration A (a configuration corresponding to the high reflective region 101) in which glass is used for the underlayer 110, the reflective layer 120 is formed of ruthenium, and the protective layer 130 is formed of silicon dioxide (Example 1) , 2), and (2) Reflectivity in the simulation for the configuration B (configuration corresponding to the low reflection region 102) (Example 3) in which only the protective layer composed of silicon dioxide is formed on the underlayer 110 composed of glass Is a graph showing the change of. The lines L1 and L2 in the graph show the change in reflectance of the above configuration A, and the line L3 shows the change in reflectance of the above configuration B. Furthermore, line L1 shows the case where the film thickness of the reflective layer 120 is 50 nm (Example 1), and line L2 shows the case where the film thickness of the reflective layer 120 is 100 nm (Example 2). The horizontal axis of this graph indicates the film thickness (unit nm) of the layer made of silicon dioxide, and the vertical axis on the left, "Reflectivity [Ru] [%]" indicates the reflectance (unit%) for configuration A of lines L1 and L2 And the right vertical axis "Reflectivity [SiO 2 ] [%]" indicates the reflectance (unit%) for the configuration B of the line L3.
　図４に示すシミュレーションの条件は次の通りである。
　光源２１０からの照射光の波長：８５０ｎｍ
　ここで、ｎ、ｋは、次式（１）で示す複素屈折率ｍにおける屈折率ｎと消衰係数ｋである。
　ｍ＝ｎ－ｉｋ　　　（１）（ｉは虚数） The conditions of the simulation shown in FIG. 4 are as follows.
Wavelength of light emitted from light source 210: 850 nm
Here, n and k are the refractive index n and the extinction coefficient k in the complex refractive index m shown by the following equation (1).
m = n-ik (1) (i is an imaginary number)
（１）実施例１（線Ｌ１に対応する構成）：下地層／反射層（Ｒｕ５０ｎｍ）／保護層
（２）実施例２（線Ｌ２に対応する構成）：下地層／反射層（Ｒｕ１００ｎｍ）／保護層（３）実施例３（線Ｌ３に対応する構成）：下地層／保護層
　下地層（実施例１～３共通）：ガラス（ＳＣＨＯＴＴ社製のＤ２６３　Ｔ　ｅｃｏ（商標））、厚さ０．５５ｍｍ、ｎ＝１．５２２４６、ｋ＝４．４５×１０－１３
　反射層（実施例１）：ルテニウム（Ｒｕ）、膜厚５０ｎｍ、ｎ＝５．２２６６６７、ｋ＝４．９０７６７２（実測値）
　反射層（実施例２）：ルテニウム（Ｒｕ）、膜厚１００ｎｍ、ｎ＝５．２１７９９７、ｋ＝４．８４３３７１（実測値）
　保護層（実施例１～３共通）：二酸化ケイ素（ＳｉＯ２）、膜厚０～３００ｎｍ（２０ｎｍ毎）、ｎ＝１．５０９１２２、ｋ＝０（実測値） (1) Example 1 (configuration corresponding to line L1): base layer / reflection layer (Ru 50 nm) / protective layer (2) Example 2 (configuration corresponding to line L2): base layer / reflection layer (Ru 100 nm) / Protective layer (3) Example 3 (Structure corresponding to line L3): Underlayer / Protective layer Underlayer (common to Examples 1 to 3): Glass (D263 T eco (trademark) manufactured by SCHOTT), thickness 0 .55 mm, n = 1.52246, k = 4.45 × 10 −13
Reflective layer (Example 1): Ruthenium (Ru), film thickness 50 nm, n = 5.226667, k = 4.907672 (measured value)
Reflective layer (Example 2): Ruthenium (Ru), film thickness 100 nm, n = 5.217997, k = 4.843371 (measured value)
Protective layer (common to Examples 1 to 3): Silicon dioxide (SiO 2 ), film thickness 0 to 300 nm (every 20 nm), n = 1.509122, k = 0 (measured value)
　図４の線Ｌ３に示すように、低反射領域１０２に対応する上記構成Ｂ（実施例３）における反射率は、ＳｉＯ２の膜厚１５０ｎｍ付近でやや小さくなっているが、全体的にはＳｉＯ２の膜厚の変化に対する変化は比較的小さく、約７．８～８．３％の範囲内の変化にとどまっている。
　これに対して、線Ｌ１、Ｌ２に示すように、高反射領域１０１に対応する上記構成Ａにおける反射率は、ＳｉＯ２の膜厚の変化にしたがって変化している。線Ｌ１（実施例１）においては、ＳｉＯ２の膜厚が０ｎｍ以上６０ｎｍ以下、及び、２００ｎｍ以上３４０ｎｍ以下の範囲において、線Ｌ３（実施例３）に示す反射率との差が５０以上となっている。また、線Ｌ２（実施例２）においては、ＳｉＯ２の膜厚が０ｎｍ以上４０ｎｍ以下、及び、２２０ｎｍ以上３００ｎｍ以下の範囲において、線Ｌ３（実施例３）に示す反射率との差が５０以上となっている。　 As indicated by line L3 in FIG. 4, the reflectance in the above-mentioned configuration B (Example 3) corresponding to the low reflection region 102 is somewhat small near the film thickness of 150 nm of SiO 2 , but overall it is SiO The change with respect to the change in the film thickness of 2 is relatively small, and remains within the range of about 7.8 to 8.3%.
On the other hand, as indicated by lines L1 and L2, the reflectance in the above configuration A corresponding to the high reflection region 101 changes in accordance with the change in the film thickness of SiO 2 . In the line L1 (Example 1), when the film thickness of SiO 2 is in the range of 0 nm to 60 nm, and 200 nm to 340 nm, the difference from the reflectance shown in the line L3 (Example 3) is 50 or more. ing. Further, in the line L2 (Example 2), when the film thickness of SiO 2 is in the range of 0 nm or more and 40 nm or less and 220 nm or more and 300 nm or less, the difference with the reflectance shown in the line L3 (Example 3) is 50 or more It has become.
　一般的に、反射型光学式エンコーダのコード板において、反射した光によって生成された縞状の像を比較的高い精度で検出するためには、高反射領域における光の反射率と、低反射領域における光の反射率との差が５０以上必要とされている。 Generally, in a code plate of a reflective optical encoder, in order to detect a striped image generated by reflected light with relatively high accuracy, the reflectance of light in a high reflection area and a low reflection area A difference of 50 or more with the light reflectance at is required.
　これにより、図４に示すように、所定の範囲において、高反射領域１０１における光の反射率と、低反射領域１０２における光の反射率との差を５０以上にすることが可能となる。 As a result, as shown in FIG. 4, the difference between the reflectance of light in the high reflection region 101 and the reflectance of light in the low reflection region 102 can be made 50 or more in a predetermined range.
　反射層１２０の膜厚は、上記構成Ａとした場合、膜の均一性、密着性、応力が生じたときのクラックの発生のしづらさなどを考慮すると、２０ｎｍ以上５００ｎｍ以下であることが好ましく、３０ｎｍ以上２００ｎｍ以下とするとより好ましく、４０ｎｍ以上１００ｎｍ以下とするとさらに好ましい。 The thickness of the reflective layer 120 is preferably 20 nm or more and 500 nm or less in the case of the above configuration A, considering the uniformity of the film, adhesion, and the occurrence of cracks when stress occurs. The thickness is more preferably 30 nm or more and 200 nm or less, and still more preferably 40 nm or more and 100 nm or less.
　ここで、図５は、ルテニウム膜に対して波長８５０ｎｍの光を照射したときのシミュレーションにおける反射率（％）の変化を示すグラフである。図５の横軸はルテニウムの膜厚（単位ｎｍ）であり、ルテニウムをガラス基板上に形成した構成である。図５に示すように、ルテニウム膜の反射率は、膜厚２０ｎｍのときに６０％を超えており、４０ｎｍでピークとなり、４０ｎｍを超えた後は６５％を超える高い反射率を維持する。したがって、ルテニウムを用いた上記反射層１２０の膜厚は、２０ｎｍ以上が好ましく、３０ｎｍ以上がより好ましく、４０ｎｍ以上とするとさらに好ましいことが分かる。 Here, FIG. 5 is a graph showing a change in reflectance (%) in a simulation when a ruthenium film is irradiated with light having a wavelength of 850 nm. The horizontal axis of FIG. 5 is a film thickness (unit nm) of ruthenium, which is a structure in which ruthenium is formed on a glass substrate. As shown in FIG. 5, the reflectance of the ruthenium film exceeds 60% at a film thickness of 20 nm, peaks at 40 nm, and maintains a high reflectance of over 65% after exceeding 40 nm. Therefore, it is understood that the film thickness of the reflective layer 120 using ruthenium is preferably 20 nm or more, more preferably 30 nm or more, and further preferably 40 nm or more.
　次に、本実施形態に係るコード板１００の耐湿性について比較例と比べつつ説明する。図６は、比較例に係る反射型光学式エンコーダのコード板３００の構成を示す模式的断面図である。図７は本実施形態の実施例に係るコード板１００の一部を拡大して示す写真であって、（ａ）は耐久試験前の状態を示し、（ｂ）は耐久試験後の状態を示す写真である。図８は比較例に係るコード板３００の一部を拡大して示す写真であって、（ａ）は耐久試験前の状態を示し、（ｂ）は耐久試験後の状態を示す写真である。 Next, the moisture resistance of the code board 100 according to the present embodiment will be described in comparison with a comparative example. FIG. 6 is a schematic cross-sectional view showing the configuration of the code plate 300 of the reflective optical encoder according to the comparative example. FIG. 7 is a photograph showing an enlarged part of the code plate 100 according to the example of the present embodiment, wherein (a) shows the state before the endurance test, and (b) shows the state after the endurance test It is a photograph. FIG. 8 is a photograph showing an enlarged part of the code plate 300 according to the comparative example, wherein (a) shows a state before the endurance test, and (b) shows a state after the endurance test.
　耐久試験は、温度８５°Ｃ、湿度８５％の恒温槽内に２４時間載置することによって行った。
　図７（ａ）、（ｂ）に示す実施例においては、高反射領域１０１では実施例１の構成、すなわち反射層１２０の膜厚が５０ｎｍの構成としており、低反射領域１０２では実施例３の構成（下地層上に二酸化ケイ素からなる保護層のみを形成した構成）としている。また、保護層１３０は厚さ２７０ｎｍとしている。 The endurance test was carried out by placing for 24 hours in a thermostat at a temperature of 85 ° C. and a humidity of 85%.
In the embodiment shown in FIGS. 7A and 7B, the configuration of the first embodiment, that is, the configuration in which the film thickness of the reflective layer 120 is 50 nm in the high reflection region 101, is used in the low reflection region 102. It is set as the structure (structure which formed only the protective layer which consists of silicon dioxides on a base layer). Further, the protective layer 130 has a thickness of 270 nm.
　図８（ａ）、（ｂ）に示す比較例におけるコード板３００は、図６に示すように、下地層３１０と、反射層３２０と、保護層３３０と、被覆層３４０とを有する。各層の構成は以下の通りである。
　下地層３１０：ガラス（ＳＣＨＯＴＴ社製のＤ２６３　Ｔ　ｅｃｏ（商標））、厚さ０．５５ｍｍ、ｎ＝１．５２２４６、ｋ＝４．４５×１０－１３
　反射層３２０：銀インジウムスズ（ＡｇＩｎＳｎ）、膜厚１００ｎｍ
　保護層３３０：酸化アルミニウム（Ａｌ２Ｏ３）、膜厚２０ｎｍ
　被覆層３４０：二酸化ケイ素（ＳｉＯ２）、膜厚１００ｎｍ The code | cord board 300 in the comparative example shown to FIG. 8 (a), (b) has the base layer 310, the reflection layer 320, the protective layer 330, and the coating layer 340, as shown in FIG. The composition of each layer is as follows.
Base layer 310: Glass (D263 T eco (trademark) manufactured by SCHOTT), thickness 0.55 mm, n = 1.52246, k = 4.45 × 10 -13
Reflective layer 320: Silver indium tin (AgInSn), film thickness 100 nm
Protective layer 330: aluminum oxide (Al 2 O 3 ), film thickness 20 nm
Coating layer 340: Silicon dioxide (SiO 2 ), film thickness 100 nm
　図６に示すように、コード板３００は、高反射領域３０１と低反射領域３０２とを有している。高反射領域３０１には、反射層３２０と、保護層３３０と、被覆層３４０とが設けられている。低反射領域３０２には、保護層３３０と、被覆層３４０とが設けられており、反射層３２０が設けられていない。光源２１０から照射された光に対する反射層３２０の反射率は、光源２１０から照射された光に対する保護層３３０の反射率、及び、光源２１０から照射された光に対する被覆層３４０の反射率よりも高い。そのため、高反射領域３０１における光の反射率は、低反射領域３０２における光の反射率よりも高い。 As shown in FIG. 6, the code plate 300 has a high reflection area 301 and a low reflection area 302. In the highly reflective region 301, a reflective layer 320, a protective layer 330, and a cover layer 340 are provided. The low reflective region 302 is provided with the protective layer 330 and the covering layer 340, and the reflective layer 320 is not provided. The reflectance of the reflective layer 320 to the light irradiated from the light source 210 is higher than the reflectance of the protective layer 330 to the light irradiated from the light source 210 and the reflectance of the covering layer 340 to the light irradiated from the light source 210 . Therefore, the reflectance of light in the high reflection area 301 is higher than the reflectance of light in the low reflection area 302.
　図７（ａ）、（ｂ）を互いに比較すると、耐久試験後においては、黒点状のゴミはわずかに見られるものの、目視において腐食は認められず、良好な状態を維持している。すなわち、高反射領域と低反射領域とでそれぞれ反射された光によって生成される縞状の像が明確に現れており、縞状の像を高い精度で検出可能である。したがって、実施例に係る構成によれば、コード板として十分な耐湿性（耐久性）を備えていることが分かる。 When FIG. 7 (a), (b) is compared with each other, although a black-spot-like refuse is slightly seen after an endurance test, corrosion is not recognized in visual observation and it has maintained the favorable state. That is, the striped image generated by the light reflected by each of the high reflection area and the low reflection area clearly appears, and the striped image can be detected with high accuracy. Therefore, according to the structure which concerns on an Example, it turns out that it is equipped with sufficient moisture resistance (durability) as a code | cord board.
　これに対して、図８（ａ）、（ｂ）を互いに比較すると、目視において少なくとも高反射領域１０１に黒い泡状のものが多数現れており、相当程度腐食が進んでいることが分かる。この腐食の程度は、図７（ｂ）と図８（ｂ）とを比較しても明確に認められる。ここで、図８（ｂ）に認められるような腐食による変化がコード板の高反射領域に生ずると、高反射領域における光の反射率が低下してしまうため、低反射領域における光の反射率との差が小さくなってしまう。このため、高反射領域と低反射領域とでそれぞれ反射された光によって生成される縞状の像を高い精度で検出することが困難となる。したがって、比較例に係る構成では耐湿性（耐久性）が十分でないことが分かる。
　本発明について上記実施形態を参照しつつ説明したが、本発明は上記実施形態に限定されるものではなく、改良の目的又は本発明の思想の範囲内において改良又は変更が可能である。 On the other hand, when FIGS. 8A and 8B are compared with each other, it can be seen that a large number of black bubbles appear in at least the high reflection area 101 visually, and the corrosion progresses to a considerable extent. The degree of this corrosion is clearly recognized also by comparing FIG. 7 (b) with FIG. 8 (b). Here, if the change due to corrosion as shown in FIG. 8B occurs in the high reflection area of the code plate, the light reflectance in the high reflection area is lowered, so the light reflectance in the low reflection area And the difference between For this reason, it becomes difficult to detect a striped image generated by light respectively reflected in the high reflection area and the low reflection area with high accuracy. Therefore, it is understood that the moisture resistance (durability) is not sufficient in the configuration according to the comparative example.
Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the above embodiment, and can be improved or changed within the scope of the improvement purpose or the spirit of the present invention.
　以上のように、本発明に係る反射型光学式エンコーダのコード板は、高反射領域における光の反射率と、低反射領域における光の反射率との差を十分確保でき、かつ、耐腐食性にすぐれ、シンプルなプロセスで製造することができる点で有用である。 As described above, the code plate of the reflective optical encoder according to the present invention can sufficiently ensure the difference between the light reflectance in the high reflection region and the light reflectance in the low reflection region, and is corrosion resistant. It is useful in that it can be manufactured by a simple process.
　１０　　反射型光学式エンコーダ
　１００　コード板
　１０１　高反射領域
　１０２　低反射領域
　１１０　下地層
　１２０　反射層
　１３０　保護層
　２００　検出ヘッド
　２１０　光源
　２２０　光検出器
　２３０　検出基板　３００　コード板
　３０１　高反射領域
　３０２　低反射領域
　３１０　下地層
　３２０　反射層
　３３０　保護層
　３４０　被覆層 DESCRIPTION OF SYMBOLS 10 reflective optical encoder 100 code board 101 high reflective area 102 low reflective area 110 underlayer 120 reflective layer 130 protective layer 200 detection head 210 light source 220 photodetector 230 detection substrate 300 code board 301 high reflective area 302 low reflective area 310 Underlayer 320 Reflective layer 330 Protective layer 340 Covering layer

Claims (5)

  1. 　高反射領域と低反射領域とが下地層に交互に配置された反射型光学式エンコーダのコード板であって、
    　前記高反射領域における光の反射率は、前記低反射領域における光の反射率よりも高く、
    　前記高反射領域における前記下地層の上に設けられ、ルテニウムを含有する反射層を備えたことを特徴とする反射型光学式エンコーダのコード板。     A code plate of a reflective optical encoder, in which high reflection areas and low reflection areas are alternately arranged in an underlayer,
    The reflectance of light in the high reflection area is higher than the reflectance of light in the low reflection area,
    A code plate of a reflective optical encoder comprising a ruthenium-containing reflective layer provided on the underlayer in the highly reflective area.
  2. 　前記反射層の膜厚は２０ｎｍ以上５００ｎｍ以下である請求項１に記載の反射型光学式エンコーダのコード板。 The code plate of a reflective optical encoder according to claim 1, wherein the film thickness of the reflective layer is 20 nm or more and 500 nm or less.
  3. 　前記反射層と前記低反射領域における前記下地層との上に設けられ、前記ルテニウムを保護する保護層を備える請求項１又は請求項２に記載の反射型光学式エンコーダのコード板。 The code | symbol board of the reflection type optical encoder of Claim 1 or Claim 2 provided with the protective layer which is provided on the said reflection layer and the said base layer in the said low reflective area | region, and protects the said ruthenium.
  4. 　前記保護層の材料は、二酸化ケイ素である請求項３に記載の反射型光学式エンコーダのコード板。 The code board of a reflective optical encoder according to claim 3, wherein the material of the protective layer is silicon dioxide.
  5. 　前記保護層の膜厚は、０ｎｍ以上６０ｎｍ以下、又は、２００ｎｍ以上３４０ｎｍ以下である請求項４に記載の反射型光学式エンコーダのコード板。 The code plate of a reflective optical encoder according to claim 4, wherein the film thickness of the protective layer is 0 nm or more and 60 nm or less, or 200 nm or more and 340 nm or less.
PCT/JP2018/041020 2017-11-08 2018-11-05 Code plate of reflective-type optical encoder WO2019093276A1 (en)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0755423A (en) * 1993-08-10 1995-03-03 Olympus Optical Co Ltd Optical displacement sensor
JPH11134715A (en) * 1997-10-28 1999-05-21 Kao Corp Optical recording medium
JPH11183199A (en) * 1997-12-25 1999-07-09 Merutekku:Kk Scale for photosensor
JP2002323347A (en) * 2001-02-20 2002-11-08 Canon Inc Reflecting scale and displacement detection device using it
JP2009002670A (en) * 2007-06-19 2009-01-08 Mitsutoyo Corp Scale for surface-reflection type encoder and surface-reflection type encoder using the same
US20150144798A1 (en) * 2012-04-18 2015-05-28 Kla-Tencor Corporation Critical dimension uniformity monitoring for extreme ultraviolet reticles
JP2017090095A (en) * 2015-11-04 2017-05-25 アルプス電気株式会社 Code plate for reflection type optical encoder

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0755423A (en) * 1993-08-10 1995-03-03 Olympus Optical Co Ltd Optical displacement sensor
JPH11134715A (en) * 1997-10-28 1999-05-21 Kao Corp Optical recording medium
JPH11183199A (en) * 1997-12-25 1999-07-09 Merutekku:Kk Scale for photosensor
JP2002323347A (en) * 2001-02-20 2002-11-08 Canon Inc Reflecting scale and displacement detection device using it
JP2009002670A (en) * 2007-06-19 2009-01-08 Mitsutoyo Corp Scale for surface-reflection type encoder and surface-reflection type encoder using the same
US20150144798A1 (en) * 2012-04-18 2015-05-28 Kla-Tencor Corporation Critical dimension uniformity monitoring for extreme ultraviolet reticles
JP2017090095A (en) * 2015-11-04 2017-05-25 アルプス電気株式会社 Code plate for reflection type optical encoder

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