WO2016143694A1 - Codeur de type à réflexion - Google Patents

Codeur de type à réflexion Download PDF

Info

Publication number
WO2016143694A1
WO2016143694A1 PCT/JP2016/056784 JP2016056784W WO2016143694A1 WO 2016143694 A1 WO2016143694 A1 WO 2016143694A1 JP 2016056784 W JP2016056784 W JP 2016056784W WO 2016143694 A1 WO2016143694 A1 WO 2016143694A1
Authority
WO
WIPO (PCT)
Prior art keywords
encoder
light
optical system
diffraction grating
light receiving
Prior art date
Application number
PCT/JP2016/056784
Other languages
English (en)
Japanese (ja)
Inventor
廉士 澤田
英雄 會田
中村　元一
久郷　智之
千尋 岡本
智英 青柳
正紀 石川
Original Assignee
並木精密宝石株式会社
アダマンド株式会社
廉士 澤田
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 並木精密宝石株式会社, アダマンド株式会社, 廉士 澤田 filed Critical 並木精密宝石株式会社
Publication of WO2016143694A1 publication Critical patent/WO2016143694A1/fr

Links

Images

Classifications

    • 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
    • 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
    • G01D5/36—Forming the light into pulses
    • G01D5/38—Forming the light into pulses by diffraction gratings

Definitions

  • the present invention relates to a small reflective encoder in which a light receiving unit receives reflected light from a diffraction grating as the movable part side diffraction grating moves, and measures the amount of movement of the diffraction grating.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 05-215515
  • Patent 4021382 Patent 4021382
  • the movement amount detection device described in Patent Document 1 causes two laser beams emitted from the same light source to enter a moving movable part side diffraction grating, and a Doppler shift is performed on the two laser beams. Then, they are further interfered with each other to irradiate the light receiving unit, thereby functioning as a so-called laser Doppler vibrometer that generates a sine wave signal composed of the intensity of light accompanying the movement of the diffraction grating. Further, when this movement amount detecting device is made to function as an encoder, the diffraction grating is divided into two rows each having a phase difference, and diffracted light from each of the divided diffraction gratings is received. By providing two light receiving sections, it is possible to generate an A phase B phase signal having a phase difference of 1 ⁇ 4 period.
  • JP 05-215515 A Japanese Patent No. 4021382
  • the conventional invention has a large divergence angle of the LD used as the light source due to its structure, and secures the amount of light to be irradiated to the light receiving element constituting the light receiving unit when further downsizing. It has been a problem that reliability cannot be achieved.
  • the gap between the light receiving unit and the diffraction grating requires a certain minimum distance for the purpose of movement of the diffraction grating. For this reason, the size of the substrate on which the light emitting portion and the light receiving portion are mounted is remarkably restricted by the previous reflection angle and the previous interval, and it is difficult to reduce the size to a size of 3 mm square or less that does not appear on the market at present.
  • the encoder described in Patent Document 2 uses only one laser beam, but on the principle of detecting a thin interference fringe about twice the slit pitch, the received light amount is reduced, the S / N ratio is reduced, and the resolution is reduced. Therefore, a long light-receiving portion in which the light-receiving elements for A-phase and B-phase are repeatedly formed in an array shape is necessary, which makes it difficult to reduce the size.
  • a reflection type that can detect both the movement amount and the movement direction with a single outgoing light, is highly reliable with a simple structure, and can easily be reduced in volume and reduced in size.
  • the purpose is to provide an encoder.
  • the invention described in the first aspect of the present invention is an interference optical system in a reflection type encoder using a diffraction grating between a laser oscillator and a movable part side diffraction grating provided on a scale.
  • the optical path length of the reference light generated in the interference optical system is limited. More specifically, in an interference optical system having diffracted light diffracted by the scale and reference light that is diffracted and reflected in the interference optical system and interferes with the diffracted light, The technical feature is that the optical path length is 4 mm or less.
  • the invention described in the second aspect of the present invention is characterized in that, in the encoder described in the first aspect, the laser oscillator and the light receiving unit are configured on the same substrate.
  • the invention described in the present application can provide a reflection type encoder having a simple structure in which both the movement amount and the movement direction can be detected by a single outgoing light.
  • This is an effect of the basic structure using the interference optical system and the reference light. That is, the encoder described in the present application divides one laser beam emitted from a light source in an interference optical system, generates reference light, and then enters and diffracts the moving movable part side diffraction grating so that the interference optical A structure that re-enters the system is used.
  • the amount of movement of the movable part side diffraction grating can be obtained by irradiating the light receiving part with light that interferes with the re-incident light and the reference light.
  • the encoder described in the present application adds a phase difference to the diffracted light from the movable part side diffraction grating in the interference optical system to be used for the A phase and the B phase, and each A phase and B phase diffracted light is used as the reference light.
  • the amount of movement of the movable part side diffraction grating it is possible to acquire not only the amount of movement of the movable part side diffraction grating but also the direction of movement from the output signal of the light receiving part.
  • the optical path length of the reference light is set to 4 mm or less, so that it is possible to provide a reflective encoder that can be easily reduced in size with a plane size of 3 mm square or less. . More specifically, by defining the optical path length of the reference light in the basic structure, an effect of downsizing the conventional encoder is given. This is because the interference optical system of the encoder used in the present application is configured by a plurality of optical paths including the reference light and the incident light.
  • the reference light forms a complete optical path only in the interference optical system, and due to the optical path length, the chip height, the planar dimensions of the entire encoder including other optical paths, and the causes thereof Machining accuracy, reliability, etc. increase or decrease. Accordingly, in the present application, when the target is downsized, by setting the value of the optical path length to 4 mm or less, the chip height of the entire encoder due to the optical path length is suppressed, and on the downsized substrate. This makes it possible to reduce the distance between the laser oscillator and the light receiving unit.
  • the size can be easily reduced by reducing the volume of the encoder chip.
  • the height and planar dimensions of the encoder chip can be reduced with a simple structure without complicating the optical path in the interference optical system.
  • the number of components used in the interference optical system can be reduced, and it becomes easy to increase the optical mounting accuracy of each element during chip assembly, and a highly reliable structure can be achieved.
  • the interference optical system used in the encoder described in the present application can directly form a plurality of optical elements on the same glass substrate and stack each component as a planar member. A highly accurate interference optical system configuration and integration can be achieved without sacrificing accuracy.
  • the second aspect of the present invention it is possible to provide a laser oscillator and a light receiving unit corresponding to miniaturization of the interference optical system.
  • the laser oscillator and the light receiving unit are configured on the same substrate. That is, in this aspect, the laser oscillator and the light receiving unit are fixed on the same substrate by die bonding or the like, so that the position adjustment between the interference optical system and the oscillator and the light receiving unit can be performed by the substrate. More specifically, the improvement in positioning accuracy in units of elements required by the downsized interference optical system is dealt with by fixing each element to the mounting substrate in advance with high accuracy.
  • the encoder according to this aspect can adjust the mounting pitch of the oscillator and the light receiving unit to the optical path of the interference optical system with high accuracy, and also assemble the entire downsized encoder. Can be performed by positioning in units of the substrate.
  • FIG. 3 is a perspective view for explaining the principle of a reflective encoder used in the embodiment of the present invention.
  • Explanatory drawing which shows the optical path of the reflection type encoder shown in FIG.
  • Optical path part enlarged view of FIG.
  • Explanatory drawing which shows the basic optical path of the reflection type encoder shown in FIG. 4 is an enlarged view of the optical path part.
  • Explanatory drawing which shows the optical path in connection with the monitor signal of the reflection type encoder shown in FIG.
  • FIG. 1 is a transparent perspective view of a reflective encoder used in the present embodiment
  • FIGS. 2, 3, 4 and 5 are explanatory views showing the whole and the basic optical path of the reflective encoder
  • FIG. 6 is the reflective encoder
  • FIG. 7 and FIG. 8 are explanatory views showing other optical paths used in the reflective encoder, respectively.
  • the scale 9 functioning as a rotor and the support structure of the entire encoder are described in the figure. Is omitted.
  • one laser beam emitted from the semiconductor laser 1 is converted into parallel rays by a lens 2 formed on the substrate.
  • the laser beam is divided by the transmissive diffraction grating 3a to generate two reference beams e1 and e2, and the divided central laser beam is incident on the movable part side diffraction grating 4 provided on the scale.
  • the light is diffracted and re-entered into the interference optical system 10.
  • the movable part side diffraction grating 4 is irradiated by irradiating the light receiving parts 7a and 7b after the interference in the interference optical system with the reference light generated at the time of division and the re-incident light re-entering the interference optical system.
  • the amount of movement can be obtained. More specifically, the intensity of the interference light output as a sine wave can be converted into an electric signal by irradiating the light receiving unit, and the amount of movement can be calculated from the transition of the signal.
  • the movable part side diffraction grating 4 is constituted by a reflection type diffraction grating, and generates two re-incident lights during the incidence and diffraction.
  • the two re-incident lights e1 are passed through the phase shifter 5 provided in the interference optical system so that the two re-incident lights are used for the A phase and the B phase, respectively. It could be diffracted light.
  • the diffracted light for the A phase and B phase is made incident on the light receiving portions 7a and 7b after interference with the reference light, so that the movable portion side diffraction grating 4 and the output signal from each light receiving portion can be obtained.
  • the moving amount and moving direction of the scale 9 could be obtained.
  • the interference optical system 10 used in the present embodiment has a chip planar dimension of 3 mm square by setting the optical path length of each reference light to 2 mm. More specifically, the height dimension of the interference optical system is limited by setting the optical path length, and the re-incident light and the reference light are determined by determining the diffraction angles of the transmission diffraction grating and the movable part side diffraction grating associated with the restriction. Thus, it is possible to easily reduce the volume and reduce the size of the entire reflective encoder including the submount 8. Note that the optical path length of the reference light in this embodiment needs to be set in a range of 4 mm or less in view of the configuration of the optical system including the movable part side diffraction grating 4 and the accuracy of the interference optical system.
  • the encoder described in this embodiment has a basic structure that passes through the interference optical system 10 and returns via the movable part side diffraction grating 4 disposed outside the interference optical system.
  • the amount of movement is obtained by irradiating incident light and reference light generated and reflected only inside the interference optical system 10 to the light receiving portions 7a and 7b after interference. Since there is a limitation on the output of the semiconductor laser that can be used in such a small optical system, the function as an encoder is ensured by setting the optical path length in the present embodiment.
  • the optical path length of the reference light functioning as diffracted light having a diffraction angle of 50 degrees or less and a diffraction order of second order or less at the transmission type diffraction grating 3a to 4 mm or less, Therefore, even when the entire chip is downsized, the amount of light applied to the light receiving unit can be secured and function as an encoder.
  • the monitoring laser light different from the two reference lights is divided in the interference optical system and irradiated to the light receiving unit 7c. Yes.
  • the encoder by providing the scale 9 with the reflector 6a, a part of the laser light incident on the movable part side diffraction grating is reflected to the light receiving part 7d. It has a structure. Therefore, the rotation speed of the scale 9 can be detected using the output from the light receiving unit 7d as a Z signal.
  • the encoder described in this embodiment uses a configuration in which four light receiving portions 7a to 7d are arranged on a common submount 8 with the semiconductor laser 1 as the center. For this reason, the arrangement of the semiconductor laser 1 and the light receiving portions 7a to 7d can be fixed on the submount 8 with high accuracy in advance. Further, in order to improve the assembly accuracy required with the miniaturization as in the present embodiment, the position adjustment between the interference optical system 10, the semiconductor laser 1, and the light receiving portions 7a to 7d is performed by the interference optical system-submount. It was possible to carry out all at once by adjusting the position.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optical Transform (AREA)

Abstract

Le problème de la présente invention consiste à fournir un codeur de type à réflexion qui puisse détecter à la fois une quantité de mouvement et une direction de déplacement à l'aide d'une seule source de lumière, qui ait une fiabilité élevée avec une conception simple et qui puisse facilement être rendu compact. La solution de la présente invention consiste en ce que, par rapport à un faisceau de référence d'un codeur de type à réflexion dans lequel un système optique d'interférence est intercalé entre un réseau de diffraction disposé sur un rotor ou une échelle linéaire, et un oscillateur laser et une unité de réception de lumière, par réglage d'une longueur de chemin optique du faisceau de référence inférieure ou égale à 4 mm, la taille globale du codeur de type à réflexion peut être réduite tout en conservant la fiabilité et la précision du codeur.
PCT/JP2016/056784 2015-03-06 2016-03-04 Codeur de type à réflexion WO2016143694A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2015045165A JP2016164529A (ja) 2015-03-06 2015-03-06 反射型エンコーダ
JP2015-045165 2015-03-06

Publications (1)

Publication Number Publication Date
WO2016143694A1 true WO2016143694A1 (fr) 2016-09-15

Family

ID=56876079

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2016/056784 WO2016143694A1 (fr) 2015-03-06 2016-03-04 Codeur de type à réflexion

Country Status (2)

Country Link
JP (1) JP2016164529A (fr)
WO (1) WO2016143694A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108681062A (zh) * 2018-04-23 2018-10-19 中国科学院合肥物质科学研究院 一种hcn激光干涉仪高速中频调制系统

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0755507A (ja) * 1993-08-17 1995-03-03 Kubota Corp 光学式エンコーダ
US20030067608A1 (en) * 2001-09-28 2003-04-10 Ulrich Steegmuller Optoelectronic component
JP2015194365A (ja) * 2014-03-31 2015-11-05 並木精密宝石株式会社 反射型エンコーダ

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0755507A (ja) * 1993-08-17 1995-03-03 Kubota Corp 光学式エンコーダ
US20030067608A1 (en) * 2001-09-28 2003-04-10 Ulrich Steegmuller Optoelectronic component
JP2015194365A (ja) * 2014-03-31 2015-11-05 並木精密宝石株式会社 反射型エンコーダ

Also Published As

Publication number Publication date
JP2016164529A (ja) 2016-09-08

Similar Documents

Publication Publication Date Title
KR101876816B1 (ko) 변위 검출 장치
US9074861B2 (en) Displacement detecting device
JP3210111B2 (ja) 変位検出装置
JP2862417B2 (ja) 変位測定装置及び方法
JP6312505B2 (ja) 光学式エンコーダおよびこれを備えた装置
US4970388A (en) Encoder with diffraction grating and multiply diffracted light
US8922785B2 (en) Method and apparatus for measuring displacement
JP3254737B2 (ja) エンコーダー
JP4416544B2 (ja) 光学式変位測定装置
US7738112B2 (en) Displacement detection apparatus, polarization beam splitter, and diffraction grating
JPH06229781A (ja) 変位測定装置
JP4077637B2 (ja) 格子干渉型変位測定装置
JP4981203B2 (ja) 光学式エンコーダー
US9612104B2 (en) Displacement detecting device
WO2015152242A1 (fr) Codeur réfléchissant
JPH03279812A (ja) 回析干渉型エンコーダ
WO2016143694A1 (fr) Codeur de type à réflexion
JP2003279383A (ja) 光学式エンコーダ
JP4416560B2 (ja) 光学式変位測定装置
JP2016001107A (ja) 変位検出装置
JP2020012784A (ja) 光学式角度センサ
JP2005055360A (ja) 光電式エンコーダ
JP3490128B2 (ja) 光電式エンコーダ
JPH0755507A (ja) 光学式エンコーダ
WO2016171108A1 (fr) Codeur réfléchissant

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16761664

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16761664

Country of ref document: EP

Kind code of ref document: A1