WO2002023130A1 - Codeur optique - Google Patents

Codeur optique Download PDF

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Publication number
WO2002023130A1
WO2002023130A1 PCT/JP2000/006276 JP0006276W WO0223130A1 WO 2002023130 A1 WO2002023130 A1 WO 2002023130A1 JP 0006276 W JP0006276 W JP 0006276W WO 0223130 A1 WO0223130 A1 WO 0223130A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
scale
pattern
optical encoder
reflecting
Prior art date
Application number
PCT/JP2000/006276
Other languages
English (en)
Japanese (ja)
Inventor
Toshikazu Satone
Original Assignee
Mitsubishi Denki Kabushiki Kaisha
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 Mitsubishi Denki Kabushiki Kaisha filed Critical Mitsubishi Denki Kabushiki Kaisha
Priority to JP2002527730A priority Critical patent/JPWO2002023130A1/ja
Priority to PCT/JP2000/006276 priority patent/WO2002023130A1/fr
Publication of WO2002023130A1 publication Critical patent/WO2002023130A1/fr

Links

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
    • G01D5/34707—Scales; Discs, e.g. fixation, fabrication, compensation
    • 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
    • G01D5/34707—Scales; Discs, e.g. fixation, fabrication, compensation
    • G01D5/34715—Scale reading or illumination devices

Definitions

  • the present invention relates to an improvement in an optical encoder used for a position detector such as a servo system.
  • FIG. 8 is a side view of a conventional optical encoder.
  • the optical encoder is fixed to the shaft 2 of the module to be detected, and is provided opposite to the scale disk 1 formed of glass or the like and the scale disk 1.
  • the light-emitting diode 3 includes a light-emitting diode 3 and a photodiode 5 that receives light emitted from the light-emitting diode 3 via the scale disk 1 at the light-receiving units 5a and 5b.
  • the scale disk 1 includes a ring-shaped outer pattern 4 and an inner pattern 14, and the outer pattern 4 includes a reflective portion 4b for reflecting light and a slit portion 4a for transmitting light. Similarly, in the inner pattern 14, a reflection portion 14b and a slit portion 14a are formed periodically and repeatedly.
  • the operation of the optical encoder configured as described above will be described with reference to FIG.
  • the scale disk 1 rotates, and the light emitted from the light emitting diode 3 passes through the slit 4a (14a) of the pattern 4 (14) to the photodiode 5
  • Light is received by the light receiving section 5a (5b).
  • the signal output from the light receiving section 5a (5b) has a rectangular waveform in proportion to the slit section 4a (14a) of the pattern 4 (14).
  • the signal output from the light receiving unit 5b is generated by shifting the phase of the signal output from the light receiving unit 5a by 7 ⁇ / 2 because the pattern 4 and the pattern 14 are out of phase by 7 ⁇ 2. .
  • the light emitted from the light emitting diode 3 is not only parallel light Ps generated in parallel from the central axis of the light emitting diode 3, but also several degrees with respect to the central axis. Includes shifted oblique lights PL1 to PL4. In particular, light at the end of the light emitting diode 3 is more likely to generate oblique lights PL1 to PL4. The oblique lights PL1 to PL4 distorted the output signal of the photodiode 5 as shown below.
  • the adjacent slits 4a (4) of the same pattern 4 (14) as shown in Fig. 9 are caused by the oblique light PL1 and PL2 that pass through the slits 4a and 14a.
  • the former is due to mutual interference between the slits 4a and 14a. That is, the parallel light Ps emitted from the light emitting diode 3 passes through the scale disk 1 from the slit portion 4a (14a) of the scale disk 1 and is received by the light receiving portion 5a (5b), and the oblique light PL 2 (PL 1) passes through the adjacent disk portion 14 a (4 a) through the scale disk 1 and is received by the light receiving portion 5 a (5 b).
  • the output signal from the photodiode 5 is not a signal completely proportional to the slit 4a of the pattern 4 and the slit 14a of the pattern 14, but is oblique from the slit 14a (4a) adjacent to each other. Under the influence of light PL 2 (PL 1), it becomes a distorted rectangular wave.
  • the phase difference between the slit portions 4a is 2 TV and the center line of the light receiving portion 5a is the phase difference X with respect to the pattern 4, the phase difference of the parallel light P s emitted from the light emitting diode 3 is given. Is X, and the light passes through the scale disk 1 from the slit portion 4a and is received by the light receiving portion 5a.
  • the phase difference of the oblique light PL 3 (PL 4) is y, which is transmitted through the scale disk 1 from the slit portion 4 a and received by the light receiving portion 5 a.
  • the light receiving section 5a receives both the light having the phase difference X and the light having the phase difference y, the light is a distorted signal including the output signal of the photodiode 5 (or the signal 'component of the phase difference y).
  • the interval between pattern 4 and pattern 14 and the interval between the repetition periods of the slit portions 4a and 14a are made wider. Therefore, there is a problem that it is impossible to manufacture a device having a small size and high resolution performance.
  • the present invention has been made to solve the above problems, and an object of the present invention is to provide an optical encoder that is hardly affected by oblique light generated from a light emitting element even when a pattern or the like is narrowed.
  • An optical encoder includes: a light emitting element that emits light; a light receiving element that receives light emitted from the light emitting element at a predetermined distance and outputs a signal based on the light amount; At least one plate-shaped scale member provided in a light path to a light-receiving element for receiving light emitted from the light source, and connected and fixed to a movable movable portion, wherein the scale member includes: A first reflecting portion for reflecting the light emitted from the light emitting element, and a plurality of slit-shaped first transmitting portions for transmitting the light at predetermined intervals in the first reflecting portion; A first pattern layer provided on the front side and a back side opposed to the first pattern layer; A second reflecting portion that reflects light emitted from the light emitting element; a second transmitting portion that transmits light that has passed through the first transmitting portion in the second reflecting portion; And a second pattern layer provided on the substrate.
  • the first pattern layer in the optical encoder according to the next invention is provided on the front surface, has an inner pattern and an outer pattern arranged side by side, and the second pattern layer is provided on the back surface.
  • the second transmission section has the same shape as the first transmission section, and is provided to face the first transmission section.
  • the scale member in the optical encoder according to the next invention comprises at least a first and a second scale plate, wherein the first scale plate is provided with a first pattern layer, The second scale layer is provided on the second scale plate, and the first scale plate and the second scale plate are arranged in parallel.
  • An optical encoder according to the next invention is characterized in that the first scale plate and the second scale plate are joined via an adhesive.
  • the second transmission section is provided continuously in a track shape, and has a plurality of the first pattern layers.
  • the optical encoder according to the next invention is characterized in that a light absorbing portion for absorbing the light emitted from the light emitting element is provided instead of the second reflecting portion for reflecting the light emitted from the light emitting element. Is what you do.
  • FIG. 1 is a partial front sectional view of an optical encoder according to an embodiment of the present invention.
  • FIG. 2 shows the front surface (a) and back surface (b) of the scale disk in Fig. 1.
  • FIG. 3 is a process diagram showing a manufacturing process of the scale disk shown in FIG.
  • FIG. 4 is a front sectional view showing that there is no influence of oblique light between slits in the same pattern in the optical encoder shown in FIG.
  • FIG. 5 is a front cross-sectional view (a) in which two scale disks according to another embodiment of the present invention are stuck together so that the reflecting portion is on the surface, and a front cross-sectional view in which the two scale discs are stuck together ( b).
  • FIG. 6 is a front sectional view of an optical encoder according to another embodiment of the present invention.
  • FIG. 7 is a plan view of a scale disk according to another embodiment of the present invention.
  • FIG. 8 is a partial front sectional view of a conventional optical encoder. .
  • FIG. 9 is a partial front sectional view showing the effect of oblique light between slits in the same pattern in a conventional optical encoder.
  • FIG. 1 is a side view of an optical encoder according to an embodiment of the present invention
  • FIG. 2 is a plan view showing a front surface (a) and a back surface (b) of the scale disk in FIG.
  • the same reference numerals as those in the related art indicate the same or corresponding parts.
  • an optical encoder is fixed to a shaft (movable part) 2 of a motor to be detected, and a scale disk 101 as a plate-like scale member formed of glass or the like;
  • a light emitting diode 3 provided as a light emitting element provided opposite to the disk 101 and light emitted from the light emitting diode 3 is used as a light emitting diode 4, 1 4, 104 on the scale disk 101.
  • 1 14 through which the photodiodes as light receiving elements are received by the light receiving sections 5a and 5b. And five.
  • the scale disk 101 has exactly the same pattern formed on the front and rear surfaces, and the surface of the scale disk 101 has the same ring-shaped first pattern as the conventional one.
  • the outer surface pattern 4 has an outer surface pattern 4 and an inner surface layer 14 as an evening layer, and the outer surface pattern 4 has a reflective portion 4b (a hatched portion) on which chrome is deposited (hatched portion) for reflecting light. 1), and a slit portion 4a (first transmitting portion) that transmits light is formed periodically in the reflecting portion 4b.
  • a reflection portion 14b first reflection portion
  • a slit portion 14a first transmission portion
  • the outer back pattern 104 includes a chrome-deposited (hatched portion) reflecting portion 104 b (second reflecting portion) and a reflecting portion 104 for reflecting light.
  • a slit portion 104 a as a second transmitting portion for transmitting light is formed periodically and repeatedly, and the inner back pattern 114 also has a reflecting portion 114 b similarly. (Second reflection part) is formed, and a slit-shaped transmission part 114a (second transmission part) is formed periodically and repeatedly in the reflection part 114b.
  • the slit portion 4a and the slit portion 104a have the same surface area and are located at positions facing each other.
  • the slits 14a and the slits 114a have the same relationship.
  • FIG. 3 is a process diagram showing a manufacturing process of the scale disk shown in FIG.
  • the resist 150 After irradiating a beam from a laser light generator (not shown) facing the surface of the scale disk 1, the resist 150 is immersed in the imaging solution to face the reflecting portions 4b and 14b. to resist 1 5 0 parts only are removed allowed formed a concave portion 1 5 0 a, the resist 1 5 0 is cured (FIG. 3 (c)) to the back surface of the c scale disc 1 resist 1 5 0 Chromium 160 thinner than the thickness is deposited (Fig. 3 (d)). The resist 150 is removed using a solvent such as thinner to form slits 104a and 114a, and the reflecting portions 104b and 114b with chromium deposited on both surfaces. A scale disk 101 having the inner back pattern 114 and the outer back pattern 104 is formed (FIG. 3 (e)).
  • FIG. 1 is a view to a front cross-sectional view that there is no influence of the oblique light between the slits in the first pattern.
  • the parallel light Ps of the light emitted from the light emitting diode 3 is divided into the slit portions 4 a, 1 in the outer surface pattern 4 and the inner surface pattern 14 of the scale disk 101. 4 Inside the scale disk 1 0 1 when incident on a Then, the light is emitted from the slit portions 104a and 114a of the outer back pattern 104 and the inner back pattern 114, and is received by the light receiving portions 5a and 5b of the photodiode 5.
  • the oblique light PL 1 (PL 2) emitted from the light-emitting diode 3 enters the slit portion 4 a (14 a), passes through the inside of the scale disk 101, and reflects at the central reflecting portion 104 b , 114b, and further reflected by the central reflectors 4b, 14b and incident on the slit 114a (104a), but is incident on the light-receiving section 5a (5b) of the photodiode 5. No light is received.
  • the parallel light Ps of the light emitted from the light emitting diode 3 enters the slit portion 4a of the scale disk 101 and transmits through the inside of the scale disk 101. Then, the light is emitted from the slit portion 104a and received by the light receiving portion 5a of the photodiode 5.
  • the oblique light PL.3, PL4 emitted from the light emitting diode 3 enters the slit portion 4a, passes through the inside of the scale disk 101, is reflected by the reflecting portion 104b, and The light is reflected by the reflecting portion 4b and is incident on the slit portion 104a, but is not received by the light receiving portion 5a of the photodiode 5 ( as described above, the output signal of the photodiode 5a is ⁇ Output a square wave signal without distortion proportional to the slits 4a, 14a, 104a, 114a of pattern 4, 14, 104, 114 without being affected by PL4 Can be.
  • the reflecting portions 104b and 114b were provided on the back surface of the scale disk 101, but instead of the reflecting portions 104b and 114b, a chromium oxide film and a chromium film were used. And a light absorbing portion for absorbing the emitted light formed by the step (b).
  • FIG. 1 The oblique light PL 1 (PL 2) emitted from the light emitting diode 3 enters the slit portion 4 a (14 a), passes through the inside of the scale disk 101, and receives the light absorption portion 104 b at the center. , 114b and is not received by the light receiving section 5a (5b) of the photodiode 5.
  • a front side light absorbing portion may be provided instead of the reflecting portions 4b and 14b of the scale disk 101.
  • FIG. Fig. 5 is a front cross-sectional view (a) in which two scale disks are stuck together so that the reflection part is on the surface, and a front cross-sectional view (b) in which two scale disks are stuck together.
  • the patterns 4, 14, 104, 114 are formed on both sides of one scale disk 101, but in this embodiment, two scale disks 201, 203 are used.
  • the step of forming a pattern on the back surface becomes unnecessary.
  • the scale member 200 has the patterns 204, 2
  • the scale disk shown in Example 1 is obtained by joining flat surfaces of a scale disk 201 having 14 and scale disks 203 having patterns 206 and 216 via an adhesive 210. This realizes a plate 101 equivalent.
  • the scale member 250 connects the plane of the scale disk 201 with the reflecting portions 206b, 216b of the scale disk 203 via an adhesive 210. By joining, the scale disk 101 shown in Example 1 is realized.
  • FIG. 6 is a front sectional view of the optical encoder.
  • the scale member 40.0 has a scale disk 201, 203 having reflecting portions 204b, 206b on one side, and a motor shaft 2 so that the reflecting portions 204b, 206b are on the outside. This is to obtain encoders 300 which are arranged side by side with a slight gap formed in the direction.
  • the scale disk 201 may be fixed to the motor shaft 2 so that the reflecting portions 204b and 206b are on the upper side as shown by the dashed line in FIG. Example 4.
  • FIG. 7 is a plan view of a scale disk.
  • the same pattern 4, 14, 104, 114, etc. was formed on both sides of the scale disk 101 or the scale members 200, 250, 400.
  • the scale disk 500 having e is provided with a pattern (not shown) similar to that of the first to third embodiments on the front surface, and a track 500 a, 500 formed of a ring-shaped recess as shown in FIG. b and reflecting portions 5110 and 520.
  • the formation of the tracks 500a and 500b on the back surface and the reflection portions 510 and 520 correspond to the patterns 104 and 114 of Examples 1 to 3. It is simpler than that.
  • the back side of the scale disk 500 is flat like the scale disk 201.
  • the pattern may not be formed, and the surface may be composed of tracks 500a and 500b and reflecting portions 5100 and 520 as shown in FIG.
  • Such a scale disk 500 and the scale disk 210 shown in Example 2 or 3 are joined by an adhesive, or the scale disk 201 and the scale disk 500 are juxtaposed.
  • the scale member may be formed by joining to the shaft 2 of the motor or the like.
  • the time required to match the pattern 204 of the scale disk 201 and the pattern of the scale disk 214 with the pattern of the scale disk 500 is the same as that of the absence of the slit portion. Only easier.
  • the oblique light transmitted through the adjacent slit portions 4a and 14a is blocked by the reflection portion. I can't.
  • the patterns 4, 14, etc. of the above-described Examples 1 to 4 are provided on the front and back surfaces of the scale disk 101, etc., but may be provided inside the scale disk 101, etc.
  • the present invention is configured as described above, and has the following effects.
  • the second transmitting portion may have, for example, a slit shape or a continuous track shape. If the second transmitting portion has the slit shape, it is difficult for the light receiving element to receive oblique light from the first transmitting portion. On the other hand, in the case of a track shape, if there are a plurality of first pattern layers, it is difficult for the light receiving element to receive oblique light from the first transmitting portion in different patterns. Therefore, since the light receiving element receives only the parallel light emitted from the light emitting element, the output signal of the light receiving element is less likely to be distorted, the distance between the slits in the same pattern can be reduced, and the encoder can be reduced in size. There is.
  • oblique light emitted from the first transmitting portion of the inner pattern and the outer pattern in the adjacent first pattern is shielded by the second reflecting portion of the second pattern.
  • the distance between the inner pattern and the outer pattern can be shortened, which has the effect of reducing the size of the encoder.
  • the scale having the first and second pattern layers is provided. There is no need to provide a member, which has the effect of facilitating the manufacture of the scale member.
  • the scale member is composed of the first and second scale plates
  • the first pattern layer provided on the first scale plate and the second pattern layer provided on the second scale plate are provided.
  • oblique light emitted from the first transmitting portion between the inner pattern and the outer pattern in the adjacent first pattern is absorbed by the light absorbing portion of the second pattern. This has the effect of reducing the distance between the pattern and the outer pattern, and consequently the encoder becomes smaller.
  • the optical encoder according to the present invention is suitable for use in detecting the position of a movable part.

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

Abstract

Cette invention se rapporte à un codeur optique, qui comprend une plaque graduée (101) disposée dans le trajet optique conduisant à des éléments photorécepteurs (5a, 5b) recevant la lumière émise par un élément photoémetteur (3) et couplés en position fixe à un arbre mobile (2), des premiers motifs (4, 14) situés sur le devant de la plaque graduée (101) et comportant des premières parties réfléchissantes (4b, 14b) réfléchissant la lumière émise par l'élément photoémetteur (3) et un grand nombre de premières parties du type à fentes (4a, 14a) laissant passer la lumière disposées à intervalle spécifié, et des seconds motifs (104, 114) placés sur l'arrière de la plaque graduée (101) à l'opposé des premiers motifs (4, 14) et comportant des secondes parties réfléchissantes (104b, 114b) réfléchissant la lumière émise par l'élément photoémetteur (3) et des secondes parties transmettant la lumière (104a, 114a) transmettant la lumière ayant traversé les premières parties transmettant la lumière (4a, 14a).
PCT/JP2000/006276 2000-09-13 2000-09-13 Codeur optique WO2002023130A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2002527730A JPWO2002023130A1 (ja) 2000-09-13 2000-09-13 光学式エンコーダ
PCT/JP2000/006276 WO2002023130A1 (fr) 2000-09-13 2000-09-13 Codeur optique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2000/006276 WO2002023130A1 (fr) 2000-09-13 2000-09-13 Codeur optique

Publications (1)

Publication Number Publication Date
WO2002023130A1 true WO2002023130A1 (fr) 2002-03-21

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PCT/JP2000/006276 WO2002023130A1 (fr) 2000-09-13 2000-09-13 Codeur optique

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JP (1) JPWO2002023130A1 (fr)
WO (1) WO2002023130A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008249646A (ja) * 2007-03-30 2008-10-16 Mitsutoyo Corp 光電式エンコーダ、及び、そのスケールの製造方法
JP2012202952A (ja) * 2011-03-28 2012-10-22 Olympus Corp 光学式エンコーダ
JP2016211901A (ja) * 2015-05-01 2016-12-15 多摩川精機株式会社 ロータリーエンコーダ

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0271118A (ja) * 1988-09-07 1990-03-09 Hitachi Ltd 移動体の位置や速度を光学的に検出する装置
JPH02231526A (ja) * 1989-03-03 1990-09-13 Canon Inc エンコーダ
JPH0481612A (ja) * 1990-07-25 1992-03-16 Sokkia Co Ltd 光学式エンコーダの目盛板及びこの目盛板を用いた光学式エンコーダ

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0271118A (ja) * 1988-09-07 1990-03-09 Hitachi Ltd 移動体の位置や速度を光学的に検出する装置
JPH02231526A (ja) * 1989-03-03 1990-09-13 Canon Inc エンコーダ
JPH0481612A (ja) * 1990-07-25 1992-03-16 Sokkia Co Ltd 光学式エンコーダの目盛板及びこの目盛板を用いた光学式エンコーダ

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008249646A (ja) * 2007-03-30 2008-10-16 Mitsutoyo Corp 光電式エンコーダ、及び、そのスケールの製造方法
JP2012202952A (ja) * 2011-03-28 2012-10-22 Olympus Corp 光学式エンコーダ
JP2016211901A (ja) * 2015-05-01 2016-12-15 多摩川精機株式会社 ロータリーエンコーダ

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