WO2016092599A1 - Optical rotary encoder - Google Patents

Optical rotary encoder Download PDF

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Publication number
WO2016092599A1
WO2016092599A1 PCT/JP2014/006184 JP2014006184W WO2016092599A1 WO 2016092599 A1 WO2016092599 A1 WO 2016092599A1 JP 2014006184 W JP2014006184 W JP 2014006184W WO 2016092599 A1 WO2016092599 A1 WO 2016092599A1
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WO
WIPO (PCT)
Prior art keywords
light
emitting element
rotating plate
light emitting
light receiving
Prior art date
Application number
PCT/JP2014/006184
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French (fr)
Japanese (ja)
Inventor
勝 宮城
Original Assignee
東京コスモス電機株式会社
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Filing date
Publication date
Application filed by 東京コスモス電機株式会社 filed Critical 東京コスモス電機株式会社
Priority to PCT/JP2014/006184 priority Critical patent/WO2016092599A1/en
Priority to JP2016563294A priority patent/JP6420846B2/en
Priority to TW104134456A priority patent/TWI664398B/en
Publication of WO2016092599A1 publication Critical patent/WO2016092599A1/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 an optical rotary encoder that outputs a signal corresponding to a rotational displacement amount of a rotating body around a rotating shaft.
  • rotary encoders are widely used to detect the rotation angle (rotation amount) and rotation direction of a rotating body.
  • rotary encoders such as a mechanical type, a magnetic type, an optical type, and the like, and they are properly used according to the application and usage environment.
  • optical rotary encoders are widely used because they are more accurate than mechanical and magnetic encoders and are not affected by peripheral magnetic fields unlike magnetic encoders.
  • an optical rotary encoder has a light emitting element that emits light, a light receiving element that receives light, and a disk-shaped rotating plate that rotates together with a rotating body.
  • the optical rotary encoder is further classified into a transmission type and a reflection type according to the positional relationship between the light emitting element and the light receiving element.
  • the transmissive optical rotary encoder has a rotating plate having a plurality of slits disposed between a light emitting element and a light receiving element arranged to face each other.
  • light emitted from the light emitting element passes through the slit portion and enters the light receiving element, or is blocked by the rotating plate portion without the slit.
  • a reflective optical rotary encoder is one in which reflective areas and non-reflective areas are alternately formed on one surface side of a rotating plate, and a light emitting element and a light receiving element are arranged on one surface side thereof. is there. The light emitted from the light emitting element is reflected in the reflection area, or absorbed or transmitted in the non-reflection area, and the light reflected in the reflection area enters the light receiving element.
  • the optical rotary encoder outputs a two-phase pulse signal according to a change in the amount of light detected by the light receiving element. Based on this signal, the rotation angle, rotation direction, etc. of the rotating body can be detected.
  • the optical rotary encoder described in Patent Document 1 includes a rotating shaft (rotating body), a light projecting unit (light emitting element) fixed on a circuit board, a light receiving unit (light receiving element), and a reflecting surface and a lens surface.
  • a transparent resin rotating part has a transparent resin rotating part (rotating plate).
  • the light projected from the light projecting unit is reflected by the reflecting surface formed in the rotating unit through the inside of the rotating unit, and then detected by the light receiving unit.
  • the rotating unit rotates with the rotation of the shaft, the light passing through the rotating unit becomes pulsed light that is strong and weak by the lens surface formed in the rotating unit, and is detected by the light receiving unit.
  • the amount of rotation and the direction of rotation of the shaft can be obtained from this pulsed light.
  • the present invention has been made to solve such a problem, and provides an optical rotary encoder capable of more accurately detecting a rotation angle of a rotating body without adopting a complicated configuration. With the goal.
  • the optical rotary encoder of the present invention includes a light emitting element that emits light, a rotating plate having a slit through which the light passes formed in a peripheral portion, and is fixed apart from the rotating plate, and the rotating plate rotates when the rotating plate rotates.
  • a reflection unit that reflects light that has passed through the slit; and a light receiving element that detects light that has passed through the slit after being reflected by the reflection unit when the rotating plate rotates.
  • Sectional drawing of the optical rotary encoder which concerns on embodiment of this invention 1 is an exploded perspective view of an optical rotary encoder according to an embodiment of the present invention.
  • Diagram for explaining the prism The figure for demonstrating the positional relationship between a light emitting element and a light receiving element.
  • the figure for demonstrating the course of the light in the prism of the light which injected from the bottom side The figure for demonstrating the course of the light in the prism of the light which injected from the bottom side
  • the figure for demonstrating the movement of the slit according to rotation of a rotating plate The figure for demonstrating the movement of the slit according to rotation of a rotating plate
  • the figure for demonstrating the movement of the slit according to rotation of a rotating plate The figure for demonstrating the movement of the slit according to rotation of a rotating plate
  • the figure for demonstrating the movement of the slit according to rotation of a rotating plate The figure which shows an example of the pulse signal which a light receiving element outputs with movement of a slit
  • FIG. 1 is a sectional view of an optical rotary encoder according to an embodiment of the present invention
  • FIG. 2 is an exploded perspective view thereof.
  • the optical rotary encoder of the present invention has a shaft 1, a case 2, a prism 3, a rotating plate 4, a mounting substrate 5, a light emitting element 6, and light receiving elements 7A and 7B.
  • the shaft 1 is supported by the case 2 so that one end of the shaft 1 is exposed outside the case 2.
  • One end of the shaft 1 exposed to the outside of the case 2 is connected to an arbitrary rotating body, for example, a motor or the like so that the rotation axis thereof coincides, and the shaft 1 rotates as the rotating body rotates.
  • the other end of the shaft 1 is housed inside the case 2 and fixed to the rotating plate 4. Therefore, the rotating plate 4 synchronizes with the rotation of the rotating body through the shaft 1 and rotates at the same rotation angle and the same rotation direction as the rotating body and the shaft 1.
  • the mounting substrate 5 is arranged in parallel with the rotating plate 4.
  • the mounting substrate 5 is fixed to the open end of the case 2.
  • a light emitting element 6 and two light receiving elements 7A and 7B are provided on a surface (referred to as a mounting surface) facing the rotating plate 4 of the mounting substrate 5. As shown in FIG. 1, the light emitting element 6 and the light receiving elements 7 ⁇ / b> A and 7 ⁇ / b> B are arranged at positions on the mounting surface that are eccentric from the rotation axis of the shaft 1.
  • the light emitting element 6 is, for example, an LED (Light Emitting Diode) and has a lens (not shown).
  • the light emitted from the LED is converted into parallel light having a predetermined beam diameter by a lens and emitted.
  • the light emitting element 6 emits this parallel light in the direction of the rotating plate 4.
  • the light receiving elements 7A and 7B are optical sensors such as photodiodes and phototransistors, for example, and generate signals corresponding to the amount of received light. Furthermore, the light receiving elements 7A and 7B have a signal processing circuit including an amplifier circuit, a waveform shaping circuit, and the like. The signal processing circuit generates and outputs a pulse signal corresponding to the amount of received light.
  • the rotating plate 4 has a plurality of slits 41 through which light can pass.
  • the slits 41 have, for example, a sector shape, a trapezoidal shape, or a sector shape, and are arranged on the rotating plate 4 radially and at equal intervals.
  • the width of the slit 41 is formed to be at least larger than the diameter of the light beam emitted from the light emitting element 6.
  • the number of slits 41 is appropriately determined according to the resolution required for the optical rotary encoder.
  • the rotating plate 4 blocks light emitted from the light emitting element 6 at portions other than the slit 41.
  • the rotating plate 4 is preferably formed of a material that does not scatter light as much as possible. Thereby, it is possible to prevent the light emitted from the light emitting element 6 from being scattered by a portion other than the slit 41 of the rotating plate 4 and detected by the light receiving elements 7A and 7B.
  • the rotating plate 4 is fixed to the end of the shaft 1 so as to be rotatable. Further, as shown in FIG. 1, a prism 3 for reflecting light emitted from the light emitting element 6 is fixed to the inner wall surface of the case 2 facing the surface on the shaft 1 side of the rotating plate 4.
  • the case 2 is provided with a notch according to the shape of the prism 3, and the prism 3 is fitted into the notch.
  • FIG. 3 is a perspective view for explaining the prism 3.
  • the prism 3 has a structure in which, for example, the side surfaces of the two right-angle prisms 31 and 32 are bonded to each other by a predetermined distance in a direction parallel to the bottom surface (a surface facing the right-angle ridge). .
  • the two inclined surfaces sandwiching the right-angle ridges of the right-angle prisms 31 and 32 reflect the light incident from the bottom surface, and change the direction of the light to a direction opposite to the incident direction.
  • the distance that is shifted when the two right-angle prisms 31 and 32 are bonded together is such that the light emitted from the light-emitting element 6 is accurately incident on the light-receiving elements 7A and 7B when the light emitted from the light-emitting element 6 is reflected by the prism 3. Adjusted.
  • a right-angle prism mirror in which a metal film or the like is deposited on two inclined surfaces sandwiching the right-angle ridge may be used.
  • the prism 3 is fixed immediately above the light emitting element 6 and the light receiving elements 7A and 7B.
  • the vertical direction of the optical rotary encoder is defined by the vertical direction in FIG.
  • this up-down direction is tentatively determined for explanation, and the up-down direction of the optical rotary encoder is not limited to this.
  • FIG. 4A is a diagram for explaining the positional relationship between the light emitting element 6 and the light receiving elements 7A and 7B.
  • FIG. 4B is a diagram for explaining a positional relationship between the right-angle prisms 31 and 32 and the light emitting element 6 and the light receiving elements 7A and 7B.
  • each part such as the light emitting element 6 is projected on a projection plane perpendicular to the rotation axis of the rotating plate 4.
  • FIG. 4A shows a horizontal positional relationship between the light emitting element 6 and the two light receiving elements 7A and 7B.
  • the light-emitting element 6 and the light-receiving elements 7A and 7B are arranged on the mounting surface of the mounting substrate 5, for example, in the order of one light-receiving element 7A, light-emitting element 6, and the other light-receiving element 7B. 'Arranged to line up.
  • a straight line L-L ′ shown in FIG. 4A and FIG. 4B shows a straight line passing through the arrangement position of the light emitting element 6 and the rotation axis of the rotating plate 4 on the projection plane.
  • the straight line l-l ′ is not parallel to the straight line L-L ′, but is inclined obliquely by a predetermined angle ⁇ .
  • FIG. 4B shows the positional relationship between the right-angle prisms 31 and 32, the light emitting element 6, and the light receiving elements 7A and 7B.
  • the light emitting element 6 is disposed on the projection plane at a position overlapping the joining surface of the two right-angle prisms 31 and 32. This means that part of the light having a predetermined light beam diameter emitted from the light emitting element 6 enters the two right-angle prisms 31 and 32, respectively.
  • the bottom face shape of the right-angle prisms 31 and 32 is shown as a trapezoid, this is an example, and may have another shape such as a parallelogram.
  • FIG. 5A and FIG. 5B are diagrams for explaining the path of light in the right-angle prisms 31 and 32 when the light emitted from the light-emitting element 6 enters the two right-angle prisms 31 and 32 from the bottom surface side.
  • the light incident from the bottom surface side of the right-angle prisms 31 and 32 has a predetermined light beam diameter.
  • FIG. 5A when light 101 having a predetermined light beam diameter is incident on the joint surface of the two right-angle prisms 31 and 32, half the light 101 is given to each of the two right-angle prisms 31 and 32. It means that the light having it enters.
  • the light incident on the respective right-angle prisms 31 and 32 travels straight inside the right-angle prisms 31 and 32 as shown in FIG. 5B and reaches the respective reflection surfaces. Thereafter, the light is reflected by the reflecting surface, and the light 102 travels through the right-angle prism 31 and the light 103 travels through the right-angle prism 32. Then, the light beams 102 and 103 traveling in the right-angle prisms 31 and 32 reach the other reflecting surface, and become light beams 104 and 105 traveling in the opposite direction to the incident parallel light 101 with the direction changed.
  • the reflection directions on the reflecting surfaces of the right-angle prisms 31 and 32 are adjusted so that the light beams 104 and 105 are incident on the two light receiving elements 7A and 7B, respectively.
  • the light emitting element 6 disposed at a position on the mounting substrate 5 that is eccentric from the rotation axis emits light having a predetermined light beam diameter.
  • the rotating plate 4 having the slit 41 rotates, the light emitted from the light emitting element 6 passes through the slit 41 or is blocked by the rotating plate 4.
  • the light that has passed through the slit 41 enters the right-angle prisms 31 and 32 that are fixed to the inner wall surface of the case 2. Thereafter, the light is reflected by the reflecting surfaces of the right-angle prisms 31 and 32, passes through the slit 41 again, and enters the light receiving elements 7A and 7B.
  • the light receiving elements 7A and 7B In response to the rotation of the rotating plate 4, the light receiving elements 7A and 7B output pulse signals corresponding to the amount of received light. By analyzing this pulse signal, the rotation angle and direction of the rotating body can be detected.
  • FIGS. 6A to 6E are views for explaining the movement of the slit 41 accompanying the rotation of the rotating plate 4.
  • FIG. 6A to 6E show the positional relationship of each part when the optical rotary encoder is viewed from above, as in FIGS. 4A, 4B, and 5A.
  • FIG. 7 is a diagram illustrating an example of output signals output from the light receiving elements 7A and 7B in accordance with the movement of the slit 41 illustrated in FIGS. 6A to 6E.
  • the output signal A indicates the output signal of one light receiving element 7A
  • the output signal B indicates the output signal of the other light receiving element 7B.
  • FIGS. 6A to 6E light is emitted from the light emitting element 6 in a direction perpendicular to the front side of the sheet. Then, the slit 41 moves along the rotation direction R along with the rotation of the rotating plate 4. Since the light emitting element 6 and the two light receiving elements 7A and 7B are arranged on the straight line ll ′ inclined by the angle ⁇ with respect to the above-described straight line LL ′, the light receiving element 7A includes the light emitting element 6 and The light enters the slit 41 before the light receiving element 7B.
  • FIG. 6A shows the positional relationship of each part at time T1 immediately before the light receiving element 7A enters the frame of the slit 41.
  • FIG. 6A shows the positional relationship of each part at time T1 immediately before the light receiving element 7A enters the frame of the slit 41.
  • FIG. 6B shows the positional relationship of each part at time T2 when time elapses from FIG. 6A and the light emitting element 6 starts to enter the frame of the slit 41.
  • the light emitted from the light emitting element 6 starts to pass through the slit 41.
  • the light that has passed through the slit 41 is reflected by the prism 3 as described above, passes through the slit 41 again, and enters the light receiving element 7A. Therefore, as shown in FIG. 7, the output signal A of the light receiving element 7A becomes high level at time T2.
  • the output signal B of the light receiving element 7B remains at the low level at time T2, as shown in FIG.
  • FIG. 6C shows the positional relationship between the respective parts at time T3 when the light receiving element 7B starts to enter the frame of the slit 41 as time elapses.
  • the reflected light from the prism 3 begins to enter both the light receiving elements 7A and 7B, as shown in FIG.
  • the output signals A and B of both the light receiving elements 7A and 7B are at the high level.
  • FIG. 6D shows the positional relationship of the respective parts at time T4 when the light receiving element 7A starts to come out of the frame of the slit 41 as time elapses.
  • the reflected light toward the light receiving element 7A starts to be blocked by the rotating plate 4.
  • the output signal B of the light receiving element 7B remains at the high level, but the output signal A of the light receiving element 7A becomes the low level.
  • FIG. 6E shows the positional relationship of each part at time T5 when the time further elapses and the light emitting element 6 starts to come out of the frame of the slit 41.
  • both the output signals A and B of the light receiving elements 7A and 7B are at a low level. Become.
  • the direction in which the light emitting element 6 and the light receiving elements 7A and 7B are arranged is set as appropriate. This direction is defined by an angle ⁇ formed by the straight line l-l ′ and the straight line L-L ′.
  • the angle ⁇ increases, the width of the slit 41 needs to be increased. Since the width of the slit 41 is limited by the size of the rotating plate 4, the number of slits, and the like, the size of the angle ⁇ may be appropriately set according to these parameters.
  • the optical rotary encoder is fixed apart from the light emitting element 6 that emits light, the rotary plate 4 having the slit 41 that allows light to pass therethrough, and the rotary plate 4.
  • a prism 3 that reflects light that has passed through the slit 41 when the rotating plate 4 rotates, and a light receiving element 7A that detects light that has been reflected by the prism 3 and then passed again through the slit 41 when the rotating plate 4 rotates. 7B.
  • the two right-angle prisms 31 and 32 reflect the light emitted from the light emitting element 6 so as to enter the two light receiving elements 7A and 7B, respectively.
  • the optical rotary encoder of the present embodiment when the arrangement positions of the light receiving elements 7A and 7B are projected on the projection plane on which the arrangement position of the light emitting elements 6 is projected perpendicular to the rotation axis of the rotating plate 4.
  • the straight line l ′ ′ passing through the arrangement position of the light receiving elements 7A and 7B and the arrangement position of the light emitting element 6 is a predetermined angle with respect to the straight line LL ′ passing through the rotation axis and the arrangement position of the light emitting element 6.
  • the light receiving elements 7A and 7B are arranged so as to be inclined.
  • a two-phase pulse signal can be easily obtained, and the rotation angle, rotation direction, etc. of the rotating body can be easily detected based on the pulse signal.
  • the slit width can be reduced as compared with the case where the light emitting element 6 and the light receiving elements 7A and 7B are arranged in the radial direction. For this reason, it is possible to further increase the number of pulses and increase the detection accuracy of the rotation angle.
  • the rotating plate 4 can be made small, and the optical rotary encoder can be downsized.
  • the optical rotary encoder of the present embodiment further includes a case 2 that houses the light emitting element 6, the rotating plate 4, the prism 3, and the light receiving elements 7A and 7B.
  • the case 2 has a notch on the inner wall surface.
  • the prism 3 is disposed in the notch.
  • the prism 3 is half embedded in the inner wall surface of the case 2, and the installation space for the prism 3 can be easily secured. Further, the optical rotary encoder can be reduced in size and thickness.
  • optical rotary encoder described above is only one embodiment of the present invention, and the present invention is not limited to the above embodiment. Below, the modification of embodiment of this invention is demonstrated in detail.
  • the light emitting element 6 and the two light receiving elements 7A and 7B are arranged so that the straight line l ′ ′ is inclined with respect to the straight line LL ′ by a predetermined angle ⁇ . It was. However, in the present invention, the light emitting element 6 and the two light receiving elements 7A and 7B may be arranged on a straight line LL ′.
  • FIG. 8 is a diagram for explaining the shape of the slit in Modification 1 of the present invention.
  • a slit 41 ′ is formed in the rotating plate 4.
  • the slit 41 ' has a shape in which the slit 41'A and the slit 41'B partially overlap.
  • the slit 41′A is a slit capable of accommodating the light emitting element 6 and the light receiving element 7A within the frame
  • the slit 41′B is a slit capable of accommodating the light emitting element 6 and the light receiving element 7B within the frame. is there.
  • the light emitting element 6 and the light receiving element 7A first enter the frame of the slit 41'A.
  • the light emitted from the light emitting element 6 passes through the slit 41'A, is reflected by the prism 3, and enters the light receiving element 7A.
  • the light receiving element 7B is not within the frame of the slit 41 ', no light is incident on the light receiving element 7B.
  • the light receiving element 7B enters the frame of the slit 41'B, and light can be detected by both the light receiving elements 7A and 7B.
  • the rotating plate 4 When the rotating plate 4 further rotates, the light receiving element 7A is removed from the frame of the slit 41′A, but the light emitting element 6 and the light receiving element 7B remain in the frame of the slit 41′B. Only 7B detects light.
  • the prism 3 is fixed apart from the movable rotating plate 4, so that the light reflection direction on the reflecting surface may vary. Therefore, the rotation angle of the rotating body can be detected more accurately without adopting a complicated configuration.
  • FIG. 9 is a view showing a modified example in which a reflective film 9 is provided instead of the prism 3.
  • a reflective film 9 that reflects incident light is provided on the inner wall surface of the case 2 facing the light emitting element 6 and the light receiving elements 7A and 7B.
  • the reflective film 9 is formed on the inner wall surface by depositing a metal film or the like.
  • a reflective plate may be provided on the inner wall surface instead of the reflective film 9.
  • the reflection film 9 or the reflection plate is provided so as to have the same shape as, for example, two inclined surfaces sandwiching the right-angle ridges of the right-angle prisms 31 and 32 described in the above embodiment.
  • the reflective film 9 or a reflecting plate can reflect so that the light from the light emitting element 6 may inject into light receiving element 7A, 7B.
  • the reflective film 9 or the reflective plate is fixed apart from the movable rotating plate 4 to fix the reflective film 9 or the reflective film.
  • the possibility that the reflection direction of light on the plate fluctuates can be eliminated, and the rotation angle of the rotating body can be detected more accurately without adopting a complicated configuration.
  • the shaft 1 is configured to be rotatably supported by the case 2.
  • a hollow shaft may be provided instead of the shaft 1, and the hollow shaft and the rotating body may be connected. Thereby, the optical rotary encoder can be further downsized.
  • the connector 8 is disposed on the surface of the mounting substrate 5 opposite to the surface on which the light emitting element 6 and the light receiving elements 7A and 7B are mounted. Power supply and signal input / output with the outside.
  • a pin terminal for through-hole mounting, a plate-shaped terminal for surface mounting, a lead wire, or the like is provided in place of the connector 8 to supply power or input / output signals from / to the outside. You may do it.

Abstract

Provided is an optical rotary encoder capable of more accurately detecting rotation angle and the like of a rotating body without employing a complicated configuration. This optical rotary encoder is provided with: a light emitting element 6 that emits light; a rotating plate 4 having slits 41 through which the light passes, said slits being formed in a peripheral portion of the rotating plate; a prism 3, which is fixed by being separated from the rotating plate 4, and which reflects the light that passed through the slits 41 while the rotating plate 4 is rotating; and light receiving elements 7A and 7B, which detect, while the rotating plate 4 is rotating, the light reflected by the prism 3 and then passed through the slits 41 again.

Description

光学式ロータリーエンコーダOptical rotary encoder
　本発明は、回転軸を中心とする回転体の回転変位量に対応する信号を出力する光学式ロータリーエンコーダに関する。 The present invention relates to an optical rotary encoder that outputs a signal corresponding to a rotational displacement amount of a rotating body around a rotating shaft.
　従来、回転体の回転角度（回転量）や回転方向を検出するため、ロータリーエンコーダが広く利用されている。ロータリーエンコーダには機械式、磁気式、光学式等、種々のタイプがあり、用途や使用環境に応じて使い分けられる。特に、光学式ロータリーエンコーダは機械式や磁気式のものに比べて高精度であり、かつ磁気式のもののように周辺磁界による影響を受けないため、広く利用されている。 Conventionally, rotary encoders are widely used to detect the rotation angle (rotation amount) and rotation direction of a rotating body. There are various types of rotary encoders such as a mechanical type, a magnetic type, an optical type, and the like, and they are properly used according to the application and usage environment. In particular, optical rotary encoders are widely used because they are more accurate than mechanical and magnetic encoders and are not affected by peripheral magnetic fields unlike magnetic encoders.
　一般的に、光学式ロータリーエンコーダは、発光する発光素子と、受光する受光素子と、回転体とともに回転する円盤状の回転板と、を有する。そして、光学式ロータリーエンコーダは、発光素子と受光素子との位置関係によりさらに透過型と反射型とに分類される。 Generally, an optical rotary encoder has a light emitting element that emits light, a light receiving element that receives light, and a disk-shaped rotating plate that rotates together with a rotating body. The optical rotary encoder is further classified into a transmission type and a reflection type according to the positional relationship between the light emitting element and the light receiving element.
　透過型の光学式ロータリーエンコーダは、向かい合うように配置された発光素子と受光素子との間に複数のスリットを有する回転板を配設したものである。透過型のロータリーエンコーダでは、発光素子が発する光は、スリットの部分を通過して受光素子に入射するか、あるいは、スリットのない回転板の部分により遮られる。 The transmissive optical rotary encoder has a rotating plate having a plurality of slits disposed between a light emitting element and a light receiving element arranged to face each other. In the transmission type rotary encoder, light emitted from the light emitting element passes through the slit portion and enters the light receiving element, or is blocked by the rotating plate portion without the slit.
　一方、反射型の光学式ロータリーエンコーダは、回転板の一方の面側に反射領域、および、非反射領域を交互に形成し、その一方の面側に発光素子と受光素子とを配置したものである。発光素子が発した光は、反射領域において反射されるか、あるいは、非反射領域において吸収あるいは透過され、反射領域において反射された光が受光素子に入射する。 On the other hand, a reflective optical rotary encoder is one in which reflective areas and non-reflective areas are alternately formed on one surface side of a rotating plate, and a light emitting element and a light receiving element are arranged on one surface side thereof. is there. The light emitted from the light emitting element is reflected in the reflection area, or absorbed or transmitted in the non-reflection area, and the light reflected in the reflection area enters the light receiving element.
　光学式ロータリーエンコーダは、受光素子が検出した光の光量変化に応じて２相のパルス信号を出力する。この信号に基づいて、回転体の回転角度や回転方向等を検出することができる。 The optical rotary encoder outputs a two-phase pulse signal according to a change in the amount of light detected by the light receiving element. Based on this signal, the rotation angle, rotation direction, etc. of the rotating body can be detected.
　反射型の光学式ロータリーエンコーダの一例が、例えば特許文献１に記載されている。
　特許文献１に記載の光学式ロータリーエンコーダは、回転する軸（回転体）、回路基板上に固定された投光部（発光素子）、受光部（受光素子）、および、反射面とレンズ面とが形成された透明樹脂性の回転部（回転板）を有する。 An example of a reflective optical rotary encoder is described in Patent Document 1, for example.
The optical rotary encoder described in Patent Document 1 includes a rotating shaft (rotating body), a light projecting unit (light emitting element) fixed on a circuit board, a light receiving unit (light receiving element), and a reflecting surface and a lens surface. Has a transparent resin rotating part (rotating plate).
　この光学式ロータリーエンコーダでは、投光部から投光された光は、回転部内部を通過して回転部に形成された反射面において反射され、その後受光部により検出される。そして、軸の回転に伴い回転部が回転すると、回転部内部を通過する光は、回転部に形成されたレンズ面により強弱のあるパルス光となり、受光部により検出される。このパルス光から軸の回転量と回転方向とが得られるようになっている。 In this optical rotary encoder, the light projected from the light projecting unit is reflected by the reflecting surface formed in the rotating unit through the inside of the rotating unit, and then detected by the light receiving unit. When the rotating unit rotates with the rotation of the shaft, the light passing through the rotating unit becomes pulsed light that is strong and weak by the lens surface formed in the rotating unit, and is detected by the light receiving unit. The amount of rotation and the direction of rotation of the shaft can be obtained from this pulsed light.
特開２０００－２９９０３４号公報JP 2000-299034 A
　ここで、反射型の光学式ロータリーエンコーダを用いて回転体の回転角等を正確に検出できるようにするためには、回転体が回転した場合でも反射面における光の反射方向が変動しないようにする必要がある。 Here, in order to be able to accurately detect the rotation angle of the rotating body using the reflective optical rotary encoder, even when the rotating body rotates, the reflection direction of the light on the reflecting surface does not fluctuate. There is a need to.
　しかしながら、特許文献１に記載された技術では、可動する回転部に反射面が形成されているため、反射面における光の反射方向が変動する可能性がある。その結果、軸の回転角等を正確に検出できないといった事態が生じうる。 However, in the technique described in Patent Document 1, since the reflecting surface is formed on the movable rotating part, the reflection direction of light on the reflecting surface may vary. As a result, a situation may occur in which the rotation angle of the shaft cannot be accurately detected.
　本発明は、このような問題を解決するためになされたものであり、複雑な構成を採用することなく回転体の回転角等をより正確に検出することができる光学式ロータリーエンコーダを提供することを目的とする。 The present invention has been made to solve such a problem, and provides an optical rotary encoder capable of more accurately detecting a rotation angle of a rotating body without adopting a complicated configuration. With the goal.
　本発明の光学式ロータリーエンコーダは、光を出射する発光素子と、前記光を通過させるスリットが周辺部に形成された回転板と、前記回転板と離れて固定され、前記回転板の回転時に前記スリットを通過した光を反射する反射部と、前記回転板の回転時に、前記反射部により反射された後、前記スリットを再度通過した光を検出する受光素子と、を備える。 The optical rotary encoder of the present invention includes a light emitting element that emits light, a rotating plate having a slit through which the light passes formed in a peripheral portion, and is fixed apart from the rotating plate, and the rotating plate rotates when the rotating plate rotates. A reflection unit that reflects light that has passed through the slit; and a light receiving element that detects light that has passed through the slit after being reflected by the reflection unit when the rotating plate rotates.
　本発明によれば、複雑な構成を採用することなく回転体の回転角等をより正確に検出することができる。 According to the present invention, it is possible to more accurately detect the rotation angle of the rotating body without adopting a complicated configuration.
本発明の実施形態に係る光学式ロータリーエンコーダの断面図Sectional drawing of the optical rotary encoder which concerns on embodiment of this invention 本発明の実施形態に係る光学式ロータリーエンコーダの分解斜視図1 is an exploded perspective view of an optical rotary encoder according to an embodiment of the present invention. プリズムについて説明するための図Diagram for explaining the prism 発光素子と受光素子との間の位置関係を説明するための図The figure for demonstrating the positional relationship between a light emitting element and a light receiving element. 直角プリズムと発光素子および受光素子との間の位置関係を説明するための図The figure for demonstrating the positional relationship between a right-angle prism, a light emitting element, and a light receiving element. 底面側から入射した光のプリズム内における光の進路を説明するための図The figure for demonstrating the course of the light in the prism of the light which injected from the bottom side 底面側から入射した光のプリズム内における光の進路を説明するための図The figure for demonstrating the course of the light in the prism of the light which injected from the bottom side 回転板の回転に応じたスリットの移動について説明するための図The figure for demonstrating the movement of the slit according to rotation of a rotating plate 回転板の回転に応じたスリットの移動について説明するための図The figure for demonstrating the movement of the slit according to rotation of a rotating plate 回転板の回転に応じたスリットの移動について説明するための図The figure for demonstrating the movement of the slit according to rotation of a rotating plate 回転板の回転に応じたスリットの移動について説明するための図The figure for demonstrating the movement of the slit according to rotation of a rotating plate 回転板の回転に応じたスリットの移動について説明するための図The figure for demonstrating the movement of the slit according to rotation of a rotating plate スリットの移動に伴い受光素子が出力するパルス信号の一例を示す図The figure which shows an example of the pulse signal which a light receiving element outputs with movement of a slit 本発明の変形例におけるスリットの形状を説明する図The figure explaining the shape of the slit in the modification of this invention プリズムの代わりに反射膜を配設した変形例を示す図The figure which shows the modification which has arrange | positioned the reflecting film instead of the prism
　以下に、本発明の実施形態について、図面を参照して詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
　［光学式ロータリーエンコーダの構成］
　図１および２を用いて、本発明の実施形態に係る光学式ロータリーエンコーダの構成の一例について説明する。図１は本発明の実施形態に係る光学式ロータリーエンコーダの断面図であり、図２はその分解斜視図である。 [Configuration of optical rotary encoder]
An example of the configuration of the optical rotary encoder according to the embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of an optical rotary encoder according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view thereof.
　図１および図２に示すように、本発明の光学式ロータリーエンコーダは、シャフト１、ケース２、プリズム３、回転板４、実装基板５、発光素子６、受光素子７Ａ、７Ｂを有する。 1 and 2, the optical rotary encoder of the present invention has a shaft 1, a case 2, a prism 3, a rotating plate 4, a mounting substrate 5, a light emitting element 6, and light receiving elements 7A and 7B.
　図１に示すように、シャフト１はその一端がケース２外に露出するようにケース２により支持される。ケース２外に露出したシャフト１の一端は、任意の回転体、例えばモーター等に回転軸が一致するように連結され、当該回転体の回転に伴ってシャフト１が回転する。 As shown in FIG. 1, the shaft 1 is supported by the case 2 so that one end of the shaft 1 is exposed outside the case 2. One end of the shaft 1 exposed to the outside of the case 2 is connected to an arbitrary rotating body, for example, a motor or the like so that the rotation axis thereof coincides, and the shaft 1 rotates as the rotating body rotates.
　シャフト１の他方の端部は、ケース２内部に収容され、回転板４に固定される。したがって、回転板４は、シャフト１を通じて回転体の回転と同調し、回転体およびシャフト１と同じ回転角度、かつ、同じ回転方向で回転する。 The other end of the shaft 1 is housed inside the case 2 and fixed to the rotating plate 4. Therefore, the rotating plate 4 synchronizes with the rotation of the rotating body through the shaft 1 and rotates at the same rotation angle and the same rotation direction as the rotating body and the shaft 1.
　また、図１に示すように、回転板４と平行に実装基板５が配置される。実装基板５はケース２の開放端に固定されている。 Further, as shown in FIG. 1, the mounting substrate 5 is arranged in parallel with the rotating plate 4. The mounting substrate 5 is fixed to the open end of the case 2.
　実装基板５の回転板４に対向する面（実装面と称する）には、発光素子６および２つの受光素子７Ａ、７Ｂが設けられる。図１に示すように、発光素子６および受光素子７Ａ、７Ｂは、シャフト１の回転軸から偏心した実装面上の位置に配置される。 A light emitting element 6 and two light receiving elements 7A and 7B are provided on a surface (referred to as a mounting surface) facing the rotating plate 4 of the mounting substrate 5. As shown in FIG. 1, the light emitting element 6 and the light receiving elements 7 </ b> A and 7 </ b> B are arranged at positions on the mounting surface that are eccentric from the rotation axis of the shaft 1.
　発光素子６は、例えばＬＥＤ（Light Emitting Diode）であり、図示しないレンズを有する。ＬＥＤの発する光は、レンズにより所定の光束径を有する平行光に変換されて出射される。発光素子６は、この平行光を回転板４の方向に出射する。 The light emitting element 6 is, for example, an LED (Light Emitting Diode) and has a lens (not shown). The light emitted from the LED is converted into parallel light having a predetermined beam diameter by a lens and emitted. The light emitting element 6 emits this parallel light in the direction of the rotating plate 4.
　受光素子７Ａ、７Ｂは、例えばフォトダイオードやフォトトランジスタ等の光センサであり、受光光量に応じた信号を生成する。さらに受光素子７Ａ、７Ｂは、増幅回路や波形整形回路等を含む信号処理回路を有し、この信号処理回路は、受光光量に応じたパルス信号を生成して出力する。 The light receiving elements 7A and 7B are optical sensors such as photodiodes and phototransistors, for example, and generate signals corresponding to the amount of received light. Furthermore, the light receiving elements 7A and 7B have a signal processing circuit including an amplifier circuit, a waveform shaping circuit, and the like. The signal processing circuit generates and outputs a pulse signal corresponding to the amount of received light.
　実装基板５の発光素子６および受光素子７Ａ、７Ｂが実装された面と反対側の面には、例えば発光素子６への電力供給、発光素子６への入力信号の伝達、受光素子７Ａ、７Ｂが出力するパルス信号等の光学式ロータリーエンコーダ外への伝達等を行うためのコネクタ８が配設される。 On the surface of the mounting substrate 5 opposite to the surface on which the light emitting element 6 and the light receiving elements 7A and 7B are mounted, for example, power supply to the light emitting element 6, transmission of an input signal to the light emitting element 6, light receiving elements 7A and 7B Is provided with a connector 8 for transmitting the pulse signal output from the optical rotary encoder to the outside.
　また、回転板４には、光を通過可能な複数のスリット４１が形成されている。スリット４１は、例えば扇形、台形あるいは扇台形の形状を有し、回転板４に放射状かつ等間隔に配列される。スリット４１の幅は、少なくとも発光素子６から出射される光の光束径より広くなるように形成される。スリット４１の個数は、光学式ロータリーエンコーダに必要とされる分解能に応じて適宜決定される。 The rotating plate 4 has a plurality of slits 41 through which light can pass. The slits 41 have, for example, a sector shape, a trapezoidal shape, or a sector shape, and are arranged on the rotating plate 4 radially and at equal intervals. The width of the slit 41 is formed to be at least larger than the diameter of the light beam emitted from the light emitting element 6. The number of slits 41 is appropriately determined according to the resolution required for the optical rotary encoder.
　回転板４は、スリット４１以外の部位では、発光素子６から出射された光を遮断する。また、回転板４は、できるだけ光を散乱しない素材で形成されることが好ましい。これにより、発光素子６から出射された光が、回転板４のスリット４１以外の部位により散乱されて受光素子７Ａ、７Ｂにより検出されることを防止することができる。 The rotating plate 4 blocks light emitted from the light emitting element 6 at portions other than the slit 41. The rotating plate 4 is preferably formed of a material that does not scatter light as much as possible. Thereby, it is possible to prevent the light emitted from the light emitting element 6 from being scattered by a portion other than the slit 41 of the rotating plate 4 and detected by the light receiving elements 7A and 7B.
　回転板４は、回転可能にシャフト１の端部に固定されている。また、図１に示すように、回転板４のシャフト１側の面に対向するケース２の内壁面には、発光素子６から発光された光を反射させるためのプリズム３が固定されている。ケース２には、プリズム３の形状に合わせて切り欠き部が設けられ、プリズム３は当該切り欠き部に嵌合される。 The rotating plate 4 is fixed to the end of the shaft 1 so as to be rotatable. Further, as shown in FIG. 1, a prism 3 for reflecting light emitted from the light emitting element 6 is fixed to the inner wall surface of the case 2 facing the surface on the shaft 1 side of the rotating plate 4. The case 2 is provided with a notch according to the shape of the prism 3, and the prism 3 is fitted into the notch.
　図３は、プリズム３について説明するための斜視図である。
　図３に示すように、プリズム３は、例えば、２つの直角プリズム３１および３２の側面部を底面（直角稜に対向する面）に平行な方向に所定の距離だけずらして貼り合わせた構造を有する。 FIG. 3 is a perspective view for explaining the prism 3.
As shown in FIG. 3, the prism 3 has a structure in which, for example, the side surfaces of the two right- angle prisms 31 and 32 are bonded to each other by a predetermined distance in a direction parallel to the bottom surface (a surface facing the right-angle ridge). .
　直角プリズム３１、３２の直角稜を挟む２つの斜面は、その底面から入射した光を反射し、その光の方向を入射方向と反対方向に変換する。 The two inclined surfaces sandwiching the right-angle ridges of the right- angle prisms 31 and 32 reflect the light incident from the bottom surface, and change the direction of the light to a direction opposite to the incident direction.
　なお、２つの直角プリズム３１、３２を貼り合わせるときにずらす距離は、発光素子６から出射された光がプリズム３により反射された場合に、受光素子７Ａ、７Ｂに正確に入射するような距離に調整される。 The distance that is shifted when the two right- angle prisms 31 and 32 are bonded together is such that the light emitted from the light-emitting element 6 is accurately incident on the light-receiving elements 7A and 7B when the light emitted from the light-emitting element 6 is reflected by the prism 3. Adjusted.
　なお、２つの直角プリズム３１、３２の代わりに、直角稜を挟む２つの斜面に金属膜等が蒸着された直角プリズムミラーを用いることとしてもよい。 In place of the two right- angle prisms 31 and 32, a right-angle prism mirror in which a metal film or the like is deposited on two inclined surfaces sandwiching the right-angle ridge may be used.
　プリズム３は、発光素子６および受光素子７Ａ、７Ｂの直上部に固定される。 The prism 3 is fixed immediately above the light emitting element 6 and the light receiving elements 7A and 7B.
　なお、本実施形態では、光学式ロータリーエンコーダの上下方向を、図１の上下方向により定義する。ただし、この上下方向は説明のために仮に定めたものであり、光学式ロータリーエンコーダの上下方向がこれに限定されるものではない。 In this embodiment, the vertical direction of the optical rotary encoder is defined by the vertical direction in FIG. However, this up-down direction is tentatively determined for explanation, and the up-down direction of the optical rotary encoder is not limited to this.
　図４Ａは、発光素子６と受光素子７Ａ、７Ｂとの間の位置関係を説明するための図である。図４Ｂは、直角プリズム３１、３２と発光素子６および受光素子７Ａ、７Ｂとの間の位置関係を説明するための図である。図４Ａ、図４Ｂでは、発光素子６等の各部が、回転板４の回転軸に垂直な投影面上に投影されている。 FIG. 4A is a diagram for explaining the positional relationship between the light emitting element 6 and the light receiving elements 7A and 7B. FIG. 4B is a diagram for explaining a positional relationship between the right- angle prisms 31 and 32 and the light emitting element 6 and the light receiving elements 7A and 7B. In FIG. 4A and FIG. 4B, each part such as the light emitting element 6 is projected on a projection plane perpendicular to the rotation axis of the rotating plate 4.
　図４Ａは、発光素子６と２つの受光素子７Ａ、７Ｂの水平方向の位置関係を示している。図４Ａに示すように、発光素子６と受光素子７Ａ、７Ｂとは、実装基板５の実装面において、例えば、一方の受光素子７Ａ、発光素子６、他方の受光素子７Ｂの順に直線ｌ－ｌ’上に並ぶように配置される。 FIG. 4A shows a horizontal positional relationship between the light emitting element 6 and the two light receiving elements 7A and 7B. As shown in FIG. 4A, the light-emitting element 6 and the light-receiving elements 7A and 7B are arranged on the mounting surface of the mounting substrate 5, for example, in the order of one light-receiving element 7A, light-emitting element 6, and the other light-receiving element 7B. 'Arranged to line up.
　ここで、図４Ａ、図４Ｂに示される直線Ｌ－Ｌ’は、上記投影面上において、発光素子６の配置位置と、回転板４の回転軸とを通る直線を示している。本実施形態では、直線ｌ－ｌ’は、直線Ｌ－Ｌ’と平行ではなく、所定の角度αだけ斜めに傾いている。 Here, a straight line L-L ′ shown in FIG. 4A and FIG. 4B shows a straight line passing through the arrangement position of the light emitting element 6 and the rotation axis of the rotating plate 4 on the projection plane. In the present embodiment, the straight line l-l ′ is not parallel to the straight line L-L ′, but is inclined obliquely by a predetermined angle α.
　詳細は後述するが、発光素子６および２つの受光素子７Ａ、７Ｂをこのように配置することにより、２つの受光素子７Ａ、７Ｂが光を検出するタイミングにずれが生じ、それぞれの受光素子７Ａ、７Ｂが出力するパルス信号に位相差を生じさせることができる。 Although details will be described later, by arranging the light emitting element 6 and the two light receiving elements 7A and 7B in this manner, the timing at which the two light receiving elements 7A and 7B detect light is shifted, and each of the light receiving elements 7A and 7A, A phase difference can be generated in the pulse signal output by 7B.
　図４Ｂは、直角プリズム３１、３２と発光素子６および受光素子７Ａ、７Ｂとの位置関係を示している。 FIG. 4B shows the positional relationship between the right- angle prisms 31 and 32, the light emitting element 6, and the light receiving elements 7A and 7B.
　図４Ｂに示すように、発光素子６は、上記投影面上において、２つの直角プリズム３１、３２の接合面に重なる位置に配置される。このことは、発光素子６から出射された所定の光束径を有する光の一部が、２つの直角プリズム３１、３２にそれぞれ入射することを意味する。 As shown in FIG. 4B, the light emitting element 6 is disposed on the projection plane at a position overlapping the joining surface of the two right- angle prisms 31 and 32. This means that part of the light having a predetermined light beam diameter emitted from the light emitting element 6 enters the two right- angle prisms 31 and 32, respectively.
　なお、図４Ｂにおいて、直角プリズム３１、３２の底面形状を台形で示しているが、これは一例であり、例えば平行四辺形等、他の形状をしていてもよい。 In addition, in FIG. 4B, although the bottom face shape of the right- angle prisms 31 and 32 is shown as a trapezoid, this is an example, and may have another shape such as a parallelogram.
　図５Ａ、図５Ｂは、発光素子６が出射した光が、２つの直角プリズム３１、３２に底面側から入射したときの直角プリズム３１、３２内における光の進路を説明するための図である。 FIG. 5A and FIG. 5B are diagrams for explaining the path of light in the right- angle prisms 31 and 32 when the light emitted from the light-emitting element 6 enters the two right- angle prisms 31 and 32 from the bottom surface side.
　直角プリズム３１、３２の底面側から入射する光が所定の光束径を有することは、上述した通りである。図５Ａに示すように、２つの直角プリズム３１、３２の接合面に所定の光束径を有する光１０１が入射することは、２つの直角プリズム３１、３２のそれぞれに光１０１の半分ずつの光量を有する光が入射することを意味する。 As described above, the light incident from the bottom surface side of the right- angle prisms 31 and 32 has a predetermined light beam diameter. As shown in FIG. 5A, when light 101 having a predetermined light beam diameter is incident on the joint surface of the two right- angle prisms 31 and 32, half the light 101 is given to each of the two right- angle prisms 31 and 32. It means that the light having it enters.
　そして、それぞれの直角プリズム３１、３２に入射した光は、図５Ｂに示すように直角プリズム３１、３２内を直進し、それぞれの反射面へと到達する。その後、反射面によって光は反射され、直角プリズム３１内を光１０２が、直角プリズム３２内を光１０３がそれぞれ進む。そして、直角プリズム３１、３２内を進む光１０２、１０３は、もう一方の反射面に到達し、さらに向きを変えられて入射した平行光１０１と反対方向に進む光１０４、１０５となる。 Then, the light incident on the respective right- angle prisms 31 and 32 travels straight inside the right- angle prisms 31 and 32 as shown in FIG. 5B and reaches the respective reflection surfaces. Thereafter, the light is reflected by the reflecting surface, and the light 102 travels through the right-angle prism 31 and the light 103 travels through the right-angle prism 32. Then, the light beams 102 and 103 traveling in the right- angle prisms 31 and 32 reach the other reflecting surface, and become light beams 104 and 105 traveling in the opposite direction to the incident parallel light 101 with the direction changed.
　本実施形態の光学式ロータリーエンコーダでは、光１０４、１０５が２つの受光素子７Ａ、７Ｂのそれぞれに入射するよう直角プリズム３１、３２の各反射面における反射方向が調整されている。 In the optical rotary encoder of the present embodiment, the reflection directions on the reflecting surfaces of the right- angle prisms 31 and 32 are adjusted so that the light beams 104 and 105 are incident on the two light receiving elements 7A and 7B, respectively.
　次に、光学式ロータリーエンコーダの動作例について詳細に説明する。 Next, an operation example of the optical rotary encoder will be described in detail.
　モーター等の回転体が回転すると、回転体に連結されたシャフト１、および、シャフト１の端部に固定された回転板４が、回転体の回転軸を中心にして回転体と同様に回転する。 When a rotating body such as a motor rotates, the shaft 1 connected to the rotating body and the rotating plate 4 fixed to the end of the shaft 1 rotate in the same manner as the rotating body about the rotation axis of the rotating body. .
　ここで、上記回転軸から偏心した実装基板５上の位置に配置された発光素子６は、所定の光束径を有する光を出射する。そして、スリット４１を有する回転板４が回転すると、発光素子６により出射された光は、スリット４１を通過するか、または、回転板４により遮光される。 Here, the light emitting element 6 disposed at a position on the mounting substrate 5 that is eccentric from the rotation axis emits light having a predetermined light beam diameter. When the rotating plate 4 having the slit 41 rotates, the light emitted from the light emitting element 6 passes through the slit 41 or is blocked by the rotating plate 4.
　そして、スリット４１を通過した光は、ケース２の内壁面に固定された直角プリズム３１、３２へ入射する。その後、光は、直角プリズム３１、３２の反射面により反射され、再度スリット４１を通過して受光素子７Ａ、７Ｂへと入射する。 The light that has passed through the slit 41 enters the right- angle prisms 31 and 32 that are fixed to the inner wall surface of the case 2. Thereafter, the light is reflected by the reflecting surfaces of the right- angle prisms 31 and 32, passes through the slit 41 again, and enters the light receiving elements 7A and 7B.
　回転板４の回転に応じて、受光素子７Ａ、７Ｂは、受光光量に対応するパルス信号を出力する。このパルス信号を解析することにより、回転体の回転角度および回転方向を検出することができる。 In response to the rotation of the rotating plate 4, the light receiving elements 7A and 7B output pulse signals corresponding to the amount of received light. By analyzing this pulse signal, the rotation angle and direction of the rotating body can be detected.
　図６Ａ～図６Ｅは、回転板４の回転に伴うスリット４１の移動について説明するための図である。図６Ａ～図６Ｅは、図４Ａ、図４Ｂ、および、図５Ａと同様に、光学式ロータリーエンコーダを上方から見たときの各部の位置関係を示している。 6A to 6E are views for explaining the movement of the slit 41 accompanying the rotation of the rotating plate 4. FIG. 6A to 6E show the positional relationship of each part when the optical rotary encoder is viewed from above, as in FIGS. 4A, 4B, and 5A.
　また、図７は、図６Ａ～図６Ｅに示したスリット４１の移動に伴い受光素子７Ａ、７Ｂが出力する出力信号の一例を示す図である。出力信号Ａは、一方の受光素子７Ａの出力信号を示し、出力信号Ｂは、他方の受光素子７Ｂの出力信号を示している。 FIG. 7 is a diagram illustrating an example of output signals output from the light receiving elements 7A and 7B in accordance with the movement of the slit 41 illustrated in FIGS. 6A to 6E. The output signal A indicates the output signal of one light receiving element 7A, and the output signal B indicates the output signal of the other light receiving element 7B.
　図６Ａ～図６Ｅにおいては、発光素子６から紙面の手前垂直方向に向かって光が出射されている。そして、回転板４の回転に伴い、スリット４１が回転方向Ｒに沿って移動する。発光素子６および２つの受光素子７Ａ、７Ｂは、前述の直線Ｌ－Ｌ’に対して角度αだけ傾いた直線ｌ－ｌ’上に配列されているため、受光素子７Ａが、発光素子６および受光素子７Ｂよりも先にスリット４１の枠内に入ることになる。 In FIGS. 6A to 6E, light is emitted from the light emitting element 6 in a direction perpendicular to the front side of the sheet. Then, the slit 41 moves along the rotation direction R along with the rotation of the rotating plate 4. Since the light emitting element 6 and the two light receiving elements 7A and 7B are arranged on the straight line ll ′ inclined by the angle α with respect to the above-described straight line LL ′, the light receiving element 7A includes the light emitting element 6 and The light enters the slit 41 before the light receiving element 7B.
　図６Ａは、受光素子７Ａがスリット４１の枠内に入る直前の時刻Ｔ１における各部の位置関係を示している。この時点で、発光素子６はスリット４１の枠内には入っていないため、発光素子６が出射した光は回転板４により遮断され、プリズム３へと到達することはない。したがって、図７の時刻Ｔ１に示すように、この時点では２つの受光素子７Ａおよび７Ｂのいずれの出力信号Ａ、Ｂもローレベルのままである。 FIG. 6A shows the positional relationship of each part at time T1 immediately before the light receiving element 7A enters the frame of the slit 41. FIG. At this time, since the light emitting element 6 is not within the frame of the slit 41, the light emitted from the light emitting element 6 is blocked by the rotating plate 4 and does not reach the prism 3. Therefore, as shown at time T1 in FIG. 7, at this time, the output signals A and B of the two light receiving elements 7A and 7B remain at the low level.
　図６Ｂは、図６Ａから時間が経過し、発光素子６がスリット４１の枠内に入り始める時刻Ｔ２での各部の位置関係を示している。この時点で、発光素子６の出射した光はスリット４１を通過し始める。スリット４１を通過した光は、上述したようにプリズム３により反射され、再度スリット４１を通過して受光素子７Ａへと入射する。したがって、図７に示すように、時刻Ｔ２において受光素子７Ａの出力信号Ａがハイレベルになる。 FIG. 6B shows the positional relationship of each part at time T2 when time elapses from FIG. 6A and the light emitting element 6 starts to enter the frame of the slit 41. At this time, the light emitted from the light emitting element 6 starts to pass through the slit 41. The light that has passed through the slit 41 is reflected by the prism 3 as described above, passes through the slit 41 again, and enters the light receiving element 7A. Therefore, as shown in FIG. 7, the output signal A of the light receiving element 7A becomes high level at time T2.
　なお、この時点では、受光素子７Ｂはスリット４１の枠内に入っていないため、図７に示すように、時刻Ｔ２では、受光素子７Ｂの出力信号Ｂはローレベルのままである。 At this time, since the light receiving element 7B is not within the frame of the slit 41, the output signal B of the light receiving element 7B remains at the low level at time T2, as shown in FIG.
　図６Ｃは、さらに時間が経過して受光素子７Ｂがスリット４１の枠内に入り始める時刻Ｔ３における各部の位置関係を示している。この時点で、スリット４１の枠内に発光素子６および２つの受光素子７Ａ、７Ｂのすべてが入るため、プリズム３からの反射光が受光素子７Ａ、７Ｂの両方に入射し始め、図７に示すように、時刻Ｔ３では、受光素子７Ａおよび７Ｂの両方の出力信号Ａ、Ｂがハイレベルとなる。 FIG. 6C shows the positional relationship between the respective parts at time T3 when the light receiving element 7B starts to enter the frame of the slit 41 as time elapses. At this time, since all of the light emitting element 6 and the two light receiving elements 7A and 7B enter the frame of the slit 41, the reflected light from the prism 3 begins to enter both the light receiving elements 7A and 7B, as shown in FIG. Thus, at time T3, the output signals A and B of both the light receiving elements 7A and 7B are at the high level.
　図６Ｄは、さらに時間が経過して受光素子７Ａがスリット４１の枠外に出始める時刻Ｔ４における各部の位置関係を示している。この時点で、受光素子７Ａへと向かう反射光は回転板４により遮られ始める。一方、発光素子６および受光素子７Ｂは未だスリット４１の枠内にあるため、発光素子６から出射された光および受光素子７Ｂへと向かう反射光は回転板４に遮られず、受光素子７Ｂへと入射する。したがって、図７に示すように、時刻Ｔ４では、受光素子７Ｂの出力信号Ｂはハイレベルのままであるが、受光素子７Ａの出力信号Ａがローレベルとなる。 FIG. 6D shows the positional relationship of the respective parts at time T4 when the light receiving element 7A starts to come out of the frame of the slit 41 as time elapses. At this time, the reflected light toward the light receiving element 7A starts to be blocked by the rotating plate 4. On the other hand, since the light emitting element 6 and the light receiving element 7B are still within the frame of the slit 41, the light emitted from the light emitting element 6 and the reflected light directed toward the light receiving element 7B are not blocked by the rotating plate 4, but to the light receiving element 7B. And incident. Accordingly, as shown in FIG. 7, at time T4, the output signal B of the light receiving element 7B remains at the high level, but the output signal A of the light receiving element 7A becomes the low level.
　図６Ｅは、さらに時間が経過し、発光素子６がスリット４１の枠外に出始める時刻Ｔ５における各部の位置関係を示している。この時点で、発光素子６から出射される光は回転板４により遮られ始めるため、図７に示すように、時刻Ｔ５では、受光素子７Ａおよび７Ｂのいずれの出力信号Ａ、Ｂもローレベルとなる。 FIG. 6E shows the positional relationship of each part at time T5 when the time further elapses and the light emitting element 6 starts to come out of the frame of the slit 41. At this time, since the light emitted from the light emitting element 6 begins to be blocked by the rotating plate 4, as shown in FIG. 7, at time T5, both the output signals A and B of the light receiving elements 7A and 7B are at a low level. Become.
　時刻Ｔ５の後、回転板４の回転に伴い、発光素子６が次のスリットの枠内に入るまでは、受光素子７Ａと７Ｂのいずれの出力信号もローレベルのままである。さらにその後は、上述した図６Ａ～図６Ｅおよび図７と同様の現象が繰り返される。 After time T5, as the rotating plate 4 rotates, the output signals of the light receiving elements 7A and 7B remain at low level until the light emitting element 6 enters the frame of the next slit. After that, the same phenomenon as in FIGS. 6A to 6E and FIG. 7 is repeated.
　なお、発光素子６および受光素子７Ａ、７Ｂが配列される方向は適宜設定される。この方向は、直線ｌ－ｌ’と直線Ｌ－Ｌ’とのなす角αにより定義される。図６Ａ～図６Ｅを参照すればわかるように、角αが大きくなると、スリット４１の幅を大きくする必要がある。スリット４１の幅は、回転板４の大きさやスリットの数等によっても制限されるので、角αの大きさもこれらのパラメータ等に応じて適宜設定すればよい。 It should be noted that the direction in which the light emitting element 6 and the light receiving elements 7A and 7B are arranged is set as appropriate. This direction is defined by an angle α formed by the straight line l-l ′ and the straight line L-L ′. As can be seen from FIGS. 6A to 6E, when the angle α increases, the width of the slit 41 needs to be increased. Since the width of the slit 41 is limited by the size of the rotating plate 4, the number of slits, and the like, the size of the angle α may be appropriately set according to these parameters.
　以上説明したように、本実施形態の光学式ロータリーエンコーダは、光を出射する発光素子６と、光を通過させるスリット４１が周辺部に形成された回転板４と、回転板４と離れて固定され、回転板４の回転時にスリット４１を通過した光を反射するプリズム３と、回転板４の回転時に、プリズム３により反射された後、スリット４１を再度通過した光を検出する受光素子７Ａ、７Ｂと、を備える。 As described above, the optical rotary encoder according to the present embodiment is fixed apart from the light emitting element 6 that emits light, the rotary plate 4 having the slit 41 that allows light to pass therethrough, and the rotary plate 4. A prism 3 that reflects light that has passed through the slit 41 when the rotating plate 4 rotates, and a light receiving element 7A that detects light that has been reflected by the prism 3 and then passed again through the slit 41 when the rotating plate 4 rotates. 7B.
　このように、可動する回転板４と離れてプリズム３が固定されることにより、反射面における光の反射方向が変動する可能性を排除することができ、複雑な構成を採用することなく回転体の回転角等をより正確に検出することができるようになる。 In this way, by fixing the prism 3 away from the movable rotating plate 4, the possibility that the reflection direction of light on the reflecting surface fluctuates can be eliminated, and the rotating body can be used without employing a complicated configuration. It becomes possible to more accurately detect the rotation angle and the like.
　また、本実施形態の光学式ロータリーエンコーダでは、２つの直角プリズム３１、３２が、発光素子６から出射された光を、２つの受光素子７Ａ、７Ｂのそれぞれに入射するように反射させる。 Further, in the optical rotary encoder of the present embodiment, the two right- angle prisms 31 and 32 reflect the light emitted from the light emitting element 6 so as to enter the two light receiving elements 7A and 7B, respectively.
　これにより、光学式ロータリーエンコーダの部品点数を削減することができ、光学式ロータリーエンコーダを容易に作成することが可能となる。その結果、光学式ロータリーエンコーダの製造コストを抑制することができる。 This makes it possible to reduce the number of parts of the optical rotary encoder and to easily create the optical rotary encoder. As a result, the manufacturing cost of the optical rotary encoder can be suppressed.
　また、本実施形態の光学式ロータリーエンコーダでは、受光素子７Ａ、７Ｂの配置位置が、回転板４の回転軸に垂直で、発光素子６の配置位置を投影した投影面上に投影された場合に、受光素子７Ａ、７Ｂの配置位置と発光素子６の配置位置とを通る直線ｌ－ｌ’が、回転軸と発光素子６の配置位置とを通る直線Ｌ－Ｌ’に対して所定の角度だけ斜めとなるよう受光素子７Ａ、７Ｂが配置される。 Further, in the optical rotary encoder of the present embodiment, when the arrangement positions of the light receiving elements 7A and 7B are projected on the projection plane on which the arrangement position of the light emitting elements 6 is projected perpendicular to the rotation axis of the rotating plate 4. The straight line l ′ ′ passing through the arrangement position of the light receiving elements 7A and 7B and the arrangement position of the light emitting element 6 is a predetermined angle with respect to the straight line LL ′ passing through the rotation axis and the arrangement position of the light emitting element 6. The light receiving elements 7A and 7B are arranged so as to be inclined.
　これにより、２相のパルス信号を容易に得ることができ、そのパルス信号に基づいて、回転体の回転角度や回転方向等を容易に検出することができる。また、後に詳しく説明するが、発光素子６および受光素子７Ａ、７Ｂを半径方向に配列する場合と比べて、スリット幅を小さくすることができる。このため、パルス数をさらに増やし、回転角度の検出精度を上げることも可能となる。 Thus, a two-phase pulse signal can be easily obtained, and the rotation angle, rotation direction, etc. of the rotating body can be easily detected based on the pulse signal. As will be described in detail later, the slit width can be reduced as compared with the case where the light emitting element 6 and the light receiving elements 7A and 7B are arranged in the radial direction. For this reason, it is possible to further increase the number of pulses and increase the detection accuracy of the rotation angle.
　また、この場合、発光素子６と受光素子７Ａ、７Ｂとの間の距離を長くすることができるようになるため、発光素子６から発せられた光が、スリット４１を通過することなく受光素子７Ａ、７Ｂにより直接検出されるクロストークの影響を抑制することができる。そのため、回転板４を小さくすることもでき、光学式ロータリーエンコーダの小型化が可能となる。 Further, in this case, since the distance between the light emitting element 6 and the light receiving elements 7A and 7B can be increased, the light emitted from the light emitting element 6 does not pass through the slit 41 and the light receiving element 7A. , 7B can suppress the influence of the crosstalk directly detected. Therefore, the rotating plate 4 can be made small, and the optical rotary encoder can be downsized.
　また、本実施形態の光学式ロータリーエンコーダでは、発光素子６、回転板４、プリズム３、受光素子７Ａ、７Ｂを収容するケース２をさらに備え、ケース２は、内壁面に切り欠き部を有し、プリズム３は当該切り欠き部に配設される。 The optical rotary encoder of the present embodiment further includes a case 2 that houses the light emitting element 6, the rotating plate 4, the prism 3, and the light receiving elements 7A and 7B. The case 2 has a notch on the inner wall surface. The prism 3 is disposed in the notch.
　これにより、プリズム３はケース２の内壁面に半ば埋め込まれることとなり、プリズム３の設置スペースを容易に確保することができる。また、光学式ロータリーエンコーダの小型化や薄型化を図ることもできる。 Thereby, the prism 3 is half embedded in the inner wall surface of the case 2, and the installation space for the prism 3 can be easily secured. Further, the optical rotary encoder can be reduced in size and thickness.
　なお、以上説明した光学式ロータリーエンコーダは、本発明の実施形態の１つに過ぎず、本発明は上記実施形態に限定されるものではない。以下に、本発明の実施形態の変形例について詳しく説明する。 The optical rotary encoder described above is only one embodiment of the present invention, and the present invention is not limited to the above embodiment. Below, the modification of embodiment of this invention is demonstrated in detail.
　［変形例１］
　上述した実施形態の光学式ロータリーエンコーダでは、直線Ｌ－Ｌ’に対し直線ｌ－ｌ’が所定の角度αだけ斜めに傾くように、発光素子６と２つの受光素子７Ａおよび７Ｂとを配置していた。しかしながら、本発明では、発光素子６と２つの受光素子７Ａ、７Ｂを、直線Ｌ－Ｌ’上に配列してもよい。 [Modification 1]
In the optical rotary encoder of the above-described embodiment, the light emitting element 6 and the two light receiving elements 7A and 7B are arranged so that the straight line l ′ ′ is inclined with respect to the straight line LL ′ by a predetermined angle α. It was. However, in the present invention, the light emitting element 6 and the two light receiving elements 7A and 7B may be arranged on a straight line LL ′.
　本変形例１では、２相のパルス信号を得るために、回転板４のスリット４１の形状を上記実施形態とは異なる形状に変更することにより、２つの受光素子７Ａおよび７Ｂに対する光の入射タイミングがずれるようにする。図８は、本発明の変形例１におけるスリットの形状を説明する図である。 In the first modification, in order to obtain a two-phase pulse signal, the shape of the slit 41 of the rotating plate 4 is changed to a shape different from that of the above-described embodiment, whereby the light incident timing to the two light receiving elements 7A and 7B. Try to shift. FIG. 8 is a diagram for explaining the shape of the slit in Modification 1 of the present invention.
　図８に示すように、本変形例１では、スリット４１’が回転板４に形成される。スリット４１’は、スリット４１’Ａとスリット４１’Ｂとが一部重なった形状を有する。スリット４１’Ａは、発光素子６および受光素子７Ａを枠内に収めることが可能なスリットであり、スリット４１’Ｂは、発光素子６および受光素子７Ｂを枠内に収めることが可能なスリットである。 As shown in FIG. 8, in the first modification, a slit 41 ′ is formed in the rotating plate 4. The slit 41 'has a shape in which the slit 41'A and the slit 41'B partially overlap. The slit 41′A is a slit capable of accommodating the light emitting element 6 and the light receiving element 7A within the frame, and the slit 41′B is a slit capable of accommodating the light emitting element 6 and the light receiving element 7B within the frame. is there.
　回転板４が回転すると、まず発光素子６および受光素子７Ａがスリット４１’Ａの枠内に入る。この場合、発光素子６から出射された光は、スリット４１’Ａを通過してプリズム３により反射され、受光素子７Ａへと入射する。この時点では、受光素子７Ｂは、スリット４１’の枠内に入っていないため、受光素子７Ｂには光が入射しない。 When the rotating plate 4 rotates, the light emitting element 6 and the light receiving element 7A first enter the frame of the slit 41'A. In this case, the light emitted from the light emitting element 6 passes through the slit 41'A, is reflected by the prism 3, and enters the light receiving element 7A. At this time, since the light receiving element 7B is not within the frame of the slit 41 ', no light is incident on the light receiving element 7B.
　さらに回転板４が回転すると、受光素子７Ｂがスリット４１’Ｂの枠内に入り、受光素子７Ａおよび７Ｂの両方で光を検出できるようになる。 When the rotating plate 4 further rotates, the light receiving element 7B enters the frame of the slit 41'B, and light can be detected by both the light receiving elements 7A and 7B.
　さらに回転板４が回転すると、受光素子７Ａがスリット４１’Ａの枠内から外れるが、発光素子６および受光素子７Ｂはスリット４１’Ｂの枠内に入ったままの状態であるため、受光素子７Ｂのみが光を検出する。 When the rotating plate 4 further rotates, the light receiving element 7A is removed from the frame of the slit 41′A, but the light emitting element 6 and the light receiving element 7B remain in the frame of the slit 41′B. Only 7B detects light.
　このようなスリット４１’の形状により、２つの受光素子７Ａおよび７Ｂへ入射する光の入射タイミングがずれ、２相のパルス信号が得られるようになる。 Such a shape of the slit 41 'shifts the incident timing of the light incident on the two light receiving elements 7A and 7B, so that a two-phase pulse signal can be obtained.
　このような変形例１の光学式ロータリーエンコーダでも、上述した実施形態と同様に、可動する回転板４と離れてプリズム３が固定されることにより、反射面における光の反射方向が変動する可能性を排除することができ、複雑な構成を採用することなく回転体の回転角等をより正確に検出することができるようになる。 Even in the optical rotary encoder of the first modification, similarly to the above-described embodiment, the prism 3 is fixed apart from the movable rotating plate 4, so that the light reflection direction on the reflecting surface may vary. Therefore, the rotation angle of the rotating body can be detected more accurately without adopting a complicated configuration.
　［変形例２］
　上述した実施形態の光学式ロータリーエンコーダでは、発光素子６から出射された光をプリズム３により反射していた。しかしながら、本発明では、プリズム３の代わりに、例えば、反射膜を用いて光の反射を行うようにしてもよい。 [Modification 2]
In the optical rotary encoder of the embodiment described above, the light emitted from the light emitting element 6 is reflected by the prism 3. However, in the present invention, instead of the prism 3, for example, a reflection film may be used to reflect light.
　図９は、プリズム３の代わりに、反射膜９を配設した変形例を示す図である。図９に示すように、発光素子６および受光素子７Ａ、７Ｂに対向するケース２の内壁面には、入射光を反射する反射膜９が設けられる。反射膜９は、金属膜等を蒸着させることにより内壁面に形成される。なお、反射膜９の代わりに反射板を内壁面に設けることとしてもよい。 FIG. 9 is a view showing a modified example in which a reflective film 9 is provided instead of the prism 3. As shown in FIG. 9, a reflective film 9 that reflects incident light is provided on the inner wall surface of the case 2 facing the light emitting element 6 and the light receiving elements 7A and 7B. The reflective film 9 is formed on the inner wall surface by depositing a metal film or the like. A reflective plate may be provided on the inner wall surface instead of the reflective film 9.
　この反射膜９または反射板は、例えば、上記実施形態で説明した直角プリズム３１、３２の直角稜を挟む２つの斜面と同様の形状となるように設けられる。これにより、上記実施形態と同様に、反射膜９または反射板は、発光素子６からの光が受光素子７Ａ、７Ｂに入射するよう反射させることができる。 The reflection film 9 or the reflection plate is provided so as to have the same shape as, for example, two inclined surfaces sandwiching the right-angle ridges of the right- angle prisms 31 and 32 described in the above embodiment. Thereby, like the said embodiment, the reflective film 9 or a reflecting plate can reflect so that the light from the light emitting element 6 may inject into light receiving element 7A, 7B.
　このような本発明の変形例２の光学式ロータリーエンコーダでも、上述した実施形態と同様に、可動する回転板４と離れて反射膜９または反射板が固定されることにより、反射膜９または反射板における光の反射方向が変動する可能性を排除することができ、複雑な構成を採用することなく回転体の回転角等をより正確に検出することができるようになる。 In such an optical rotary encoder according to the second modification of the present invention, as in the above-described embodiment, the reflective film 9 or the reflective plate is fixed apart from the movable rotating plate 4 to fix the reflective film 9 or the reflective film. The possibility that the reflection direction of light on the plate fluctuates can be eliminated, and the rotation angle of the rotating body can be detected more accurately without adopting a complicated configuration.
　［変形例３］
　上述した実施形態の光学式ロータリーエンコーダでは、シャフト１がケース２に回転可能に支持される構成としていた。しかしながら、本発明では、シャフト１の代わりに中空軸を設け、当該中空軸と回転体とを連結してもよい。これにより、光学式ロータリーエンコーダをより小型化することができる。 [Modification 3]
In the optical rotary encoder of the embodiment described above, the shaft 1 is configured to be rotatably supported by the case 2. However, in the present invention, a hollow shaft may be provided instead of the shaft 1, and the hollow shaft and the rotating body may be connected. Thereby, the optical rotary encoder can be further downsized.
　また、上述した実施形態の光学式ロータリーエンコーダでは、実装基板５において、発光素子６および受光素子７Ａ、７Ｂが実装された面とは反対側の面にコネクタ８を配設し、当該コネクタ８を介して電力供給や外部との信号入出力等を行っていた。しかしながら、本発明では、コネクタ８の代わりに、スルーホール実装用のピン端子や面実装用の板状端子、あるいはリード線等を配設して電力供給や外部との信号の入出力等を行うようにしてもよい。 In the optical rotary encoder of the above-described embodiment, the connector 8 is disposed on the surface of the mounting substrate 5 opposite to the surface on which the light emitting element 6 and the light receiving elements 7A and 7B are mounted. Power supply and signal input / output with the outside. However, in the present invention, a pin terminal for through-hole mounting, a plate-shaped terminal for surface mounting, a lead wire, or the like is provided in place of the connector 8 to supply power or input / output signals from / to the outside. You may do it.
　１　シャフト
　２　ケース
　３　プリズム
　３１，３２　直角プリズム
　４　回転板
　４１，４１’，４１’Ａ，４１’Ｂ　スリット
　５　実装基板
　６　発光素子
　７Ａ，７Ｂ　受光素子
　８　コネクタ
　９　反射膜
　１０１，１０２，１０３，１０４，１０５　光 DESCRIPTION OF SYMBOLS 1 Shaft 2 Case 3 Prism 31, 32 Right angle prism 4 Rotating plate 41, 41 ', 41'A, 41'B Slit 5 Mounting board 6 Light emitting element 7A, 7B Light receiving element 8 Connector 9 Reflective film 101,102,103,104 , 105 light

Claims (5)

  1. 　光を出射する発光素子と、
    　前記光を通過させるスリットが周辺部に形成された回転板と、
    　前記回転板と離れて固定され、前記回転板の回転時に前記スリットを通過した光を反射する反射部と、
    　前記回転板の回転時に、前記反射部により反射された後、前記スリットを再度通過した光を検出する受光素子と、
    　を備える光学式ロータリーエンコーダ。     A light emitting element that emits light;
    A rotating plate having a slit through which the light passes formed in a peripheral portion;
    A reflecting portion that is fixed apart from the rotating plate and reflects light that has passed through the slit when the rotating plate is rotated;
    A light-receiving element that detects light that has passed through the slit again after being reflected by the reflecting portion during rotation of the rotating plate;
    Optical rotary encoder with
  2. 　前記反射部は、２つのプリズムにより構成され、それぞれのプリズムは、前記発光素子から出射された光を、２つの受光素子のそれぞれに入射するように反射させる
    　請求項１に記載の光学式ロータリーエンコーダ。     2. The optical rotary encoder according to claim 1, wherein the reflection unit includes two prisms, and each of the prisms reflects light emitted from the light emitting element so as to enter each of the two light receiving elements. .
  3. 　前記受光素子の配置位置と前記発光素子の配置位置とが、前記回転板の回転軸に垂直な投影面上に投影された場合に、前記受光素子の配置位置と前記発光素子の配置位置とを通る直線が、前記回転軸と前記発光素子の配置位置とを通る直線に対して所定の角度だけ斜めとなるよう前記受光素子が配置される
    　請求項１に記載の光学式ロータリーエンコーダ。     When the arrangement position of the light receiving element and the arrangement position of the light emitting element are projected on a projection plane perpendicular to the rotation axis of the rotating plate, the arrangement position of the light receiving element and the arrangement position of the light emitting element are obtained. 2. The optical rotary encoder according to claim 1, wherein the light receiving element is arranged such that a straight line passing therethrough is inclined at a predetermined angle with respect to a straight line passing through the rotation axis and the arrangement position of the light emitting element.
  4. 　前記発光素子、前記回転板、前記反射部、前記受光素子を収容するケースをさらに備え、
    　前記ケースは、内壁面に切り欠き部を有し、前記反射部は当該切り欠き部に配設される
    　請求項１に記載の光学式ロータリーエンコーダ。     A case for accommodating the light emitting element, the rotating plate, the reflecting portion, and the light receiving element;
    The optical rotary encoder according to claim 1, wherein the case has a cutout portion on an inner wall surface, and the reflection portion is disposed in the cutout portion.
  5. 　前記反射部は、光を反射する反射膜または反射板である
    　請求項１に記載の光学式ロータリーエンコーダ。
          The optical rotary encoder according to claim 1, wherein the reflection unit is a reflection film or a reflection plate that reflects light.
PCT/JP2014/006184 2014-12-11 2014-12-11 Optical rotary encoder WO2016092599A1 (en)

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