JPS60222717A - Optical encoder - Google Patents
Optical encoderInfo
- Publication number
- JPS60222717A JPS60222717A JP7833984A JP7833984A JPS60222717A JP S60222717 A JPS60222717 A JP S60222717A JP 7833984 A JP7833984 A JP 7833984A JP 7833984 A JP7833984 A JP 7833984A JP S60222717 A JPS60222717 A JP S60222717A
- Authority
- JP
- Japan
- Prior art keywords
- light
- light receiving
- receiving elements
- position information
- window
- Prior art date
- Legal status (The legal status 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 status listed.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 title claims description 5
- 239000000758 substrate Substances 0.000 claims description 6
- 230000001678 irradiating effect Effects 0.000 claims 1
- 239000011295 pitch Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
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
- G01D5/36—Forming the light into pulses
Abstract
Description
【発明の詳細な説明】
（技術分野）
本発明は、光学式エンコーダに関し、例えばフロッピー
ディスク記憶装置等における磁気ヘッドの位置決め情報
を形成するための光学式エンコーダに用いることができ
る。DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an optical encoder, and can be used, for example, in an optical encoder for forming positioning information of a magnetic head in a floppy disk storage device or the like.
（背景技術）
現在、可動物体の位置を正確に制御するための位置情報
発生装置（以後、エンコーダと記す。）は、ロボットや
精密機器において欠かすことのできない装置となってい
る。エンコーダには、回転式のロータリーエンコーダと
直線動作のリニアエンコーダとがあるが、動作原理にお
いて両者とも同一である。(Background Art) Currently, position information generating devices (hereinafter referred to as encoders) for accurately controlling the position of movable objects have become indispensable devices for robots and precision instruments. Encoders include rotary encoders and linear encoders, both of which operate on the same principle.
また、エンコーダに用いられている方式としては光学式
と磁気式とがあり、それらは可動基板上に光学的または
磁気的に検出可能な情報を予じめ記録しておき、その情
報を受光素子または磁気ヘッドによって読み出し、その
読み出した位置情報を電気信号主にパルス列に変換する
。エンコーダにとって最も重要な特性は、エンコーダの
分解能であり、ｌｐｍ程度の分解能が要求されることが
多くなっている。しかしながら、可動基板上に記録され
た位置情報のピッチ、受光素子及び磁ヘッドの分解能は
従来５０〜２００ ｇｍ程度にしかならなかった。これ
らの従来の問題点に鑑みて、先に本出願人は特願昭５９
−２１８４０号においてディジタル的な位置情報とアナ
ログ的な位置情報を組合せたエンコーダを提案した。こ
れは移動方向に一列に配列された複数のほぼＶ字形の溝
を有する反射板を用いたものであるが、この反射板の材
質は現在プラスチックに限られているという欠点があっ
た。In addition, there are two types of encoders: optical and magnetic.In these, information that can be detected optically or magnetically is recorded on a movable substrate in advance, and the information is transferred to a light-receiving element. Alternatively, it is read out using a magnetic head, and the read position information is converted into an electrical signal, mainly a pulse train. The most important characteristic of an encoder is its resolution, and resolution on the order of lpm is increasingly required. However, the pitch of the positional information recorded on the movable substrate and the resolution of the light receiving element and the magnetic head have conventionally been only about 50 to 200 gm. In view of these conventional problems, the applicant first filed a patent application filed in 1983.
In No. 21840, we proposed an encoder that combines digital position information and analog position information. This uses a reflector plate having a plurality of approximately V-shaped grooves arranged in a line in the direction of movement, but the material of this reflector plate is currently limited to plastic.
（発明の目的）
本発明はこれらの問題点を解決するためのもので、構造
が簡単で、かつ位置情報の分割能がすぐれており、また
、反射板の材質が限定されることなく任意のものが使用
可能な、例えば、高温にさらされる環境での用途などに
も利用可能な新しいエンコーダを提供することを目的と
する。(Purpose of the Invention) The present invention is intended to solve these problems, and has a simple structure and excellent ability to divide position information. It is an object of the present invention to provide a new encoder that can be used for applications such as applications in environments exposed to high temperatures.
（発明の構成及び作用 ）
第１図は本発明の一実施例を示す構成図である。１０は
可動物体で、矢印２１のような両方向に移動可能であり
、表面上に移動方向と平行に２列の反射板をこの２列の
互いに１／２ピツチになるように設けている。１１は反
射板で、発光素子１４．１５からの光を反射させるもの
であれば任意の材質でもよい。１２は固定スリットで、
可動物体ｌｏと発光素子１４．１５及び受光素子１６．
１７の間に所望の位置に位置し、反射板１１と同じピッ
チと同じ大きさの窓１３を有している。１３は窓で、発
光素子１４．１５から発せられる光束が通過する。１４
．１５は発光素子で、固定スリット１２の上部に設けら
れかつ、二列−に並んだ窓の各中点の真上になるように
位置し、２個設けられている。また、発光素子１４は、
これよりは発せられた光が反射板１１によって反射され
て受光素子１１３．１７に当たるように調整されている
。発光素子は、例えばＬＥＤなどで構成され、入力端子
１θに供給される駆動電圧に従い発光する。１６．１７
は受光素子で、発光素子１４．１５から発せられた光が
反射板１１によって反射され、その反射光を電気信号に
変換し、発光素子１４．１５と同様所望の位置に２個設
ける。受光素子は、例えばシリコンフォトダイオードで
構成されている。(Structure and operation of the invention) FIG. 1 is a block diagram showing an embodiment of the invention. A movable object 10 is movable in both directions as indicated by an arrow 21, and two rows of reflecting plates are provided on its surface in parallel to the direction of movement so that the two rows are 1/2 pitch from each other. Reference numeral 11 denotes a reflecting plate, which may be made of any material as long as it reflects the light from the light emitting elements 14 and 15. 12 is a fixed slit,
A movable object lo, a light emitting element 14.15, and a light receiving element 16.
The window 13 is located at a desired position between the reflectors 17 and has the same pitch and size as the reflector 11. 13 is a window through which light beams emitted from light emitting elements 14 and 15 pass. 14
．． Reference numeral 15 denotes a light emitting element, and two light emitting elements are provided above the fixed slit 12 and positioned directly above the midpoints of the windows arranged in two rows. Further, the light emitting element 14 is
Adjustments are made so that the emitted light is reflected by the reflecting plate 11 and hits the light receiving elements 113, 17. The light emitting element is composed of, for example, an LED, and emits light according to a drive voltage supplied to the input terminal 1θ. 16.17
1 is a light receiving element, in which the light emitted from the light emitting elements 14.15 is reflected by the reflecting plate 11, and the reflected light is converted into an electric signal, and two of them are provided at desired positions similarly to the light emitting elements 14.15. The light receiving element is composed of, for example, a silicon photodiode.
１８は差動増幅器で、２個の受光素子ＩＢ、 １７から
得られる電気信号の差を出力する。１９は入力端子で、
２個の発光素子１４．１５が発光するための駆動電圧が
入力される端子である。２０は出力端子で、差動増幅器
１６の出力される端子である。２１は矢印で、可動物体
１０の移動方向を示す。A differential amplifier 18 outputs the difference between the electrical signals obtained from the two light receiving elements IB and 17. 19 is an input terminal,
This is a terminal to which a driving voltage for the two light emitting elements 14 and 15 to emit light is input. Reference numeral 20 denotes an output terminal, which is a terminal from which the differential amplifier 16 outputs. 21 is an arrow indicating the moving direction of the movable object 10.
次に動作を説明すると、入力端子１９に駆動電圧が印加
され、２個の発光素子１４．１５から光が発せられる。Next, the operation will be described. A driving voltage is applied to the input terminal 19, and light is emitted from the two light emitting elements 14 and 15.
ここで、可動物体１０が矢印２１の方向に移動すると、
可動物体１０上の反射板１１が固定スリッＨ２の窓工３
から見て、見え隠れする。前記光が窓１３を通して反射
板１１に反射して受光素子１６．１７に照射され、電気
信号に変換される。そして３各電気信号は差動増幅器１
８を介して差を取り、出力端子２０からその差分電圧が
出力される。従って、差動増幅器１８の出力は反射板１
１に対する相対的位置を示し、つまりこれは可動物体に
対する相対的位置に対応する。Here, when the movable object 10 moves in the direction of the arrow 21,
Window work 3 in which the reflector 11 on the movable object 10 is a fixed slit H2
When you look at it, it appears and disappears. The light passes through the window 13 and is reflected by the reflection plate 11, and is irradiated onto the light receiving elements 16 and 17, where it is converted into an electrical signal. and 3 each electrical signal is passed through a differential amplifier 1
8, and the differential voltage is output from the output terminal 20. Therefore, the output of the differential amplifier 18 is
1, which corresponds to the relative position to the movable object.
第２図は本発明の一実施例における可動物体の移動に対
する２個の受光素子及び差動増幅器の出力特性を示す。FIG. 2 shows the output characteristics of two light receiving elements and a differential amplifier with respect to the movement of a movable object in an embodiment of the present invention.
波形ａは、２個の受光素子の内の１つの出力を表わす。Waveform a represents the output of one of the two light receiving elements.
この波形は図よりわかるようにかなりブロードな波形と
なっているので、最大反射位置が不明確であり位置情報
を検出するのが困難である。波形すは、残りの受光素子
の出力波形である。この波形は１／２ピツチずれた反射
板からの受光素子であり、波形ａと形は同じであるが、
周期が１７２ピツチずれている。波形Ｃは、差動増幅器
の出力波形である。この波形は波形ａ。As can be seen from the figure, this waveform is quite broad, so the maximum reflection position is unclear and it is difficult to detect positional information. Waveform S is the output waveform of the remaining light receiving elements. This waveform is a light receiving element from a reflecting plate shifted by 1/2 pitch, and has the same shape as waveform a, but
The period is off by 172 pitches. Waveform C is the output waveform of the differential amplifier. This waveform is waveform a.
ｂの差分を表わしており、ゼロクロス点は図かられかる
ように明確である。波形Ｃの山と谷の距離は反射板ピッ
チの１／２と等しく、フロッピーディスクドライバ等に
おいては５″形で ′２８５ ｇｒｎあるいは３．５”
形で１８８ ｇ ｍである。ここて、１８８ ｇｍの可
動物体の移動に対し、差動増幅器の出力が山から谷まで
ゼロクロス点を交鎖して変化するので、Ｉｇｍの分解能
を得るためには差動受光出力のＳ／Ｎ比が４５．５ｄ
Ｂ ｔ： １８８７１ ）以上であればよい。一般に、
発光素子としてＬＥＤを、受光素子としてシリコンフォ
トダイオード等を用いると、Ｓ／Ｎ比は８０ｄＢ以上確
実に取れる。これは上記のものの周波数帯域が狭いため
である。したがって、本発明におけるＳ／Ｎ比は変動成
分を考慮に入れても５０ｄＢを容易に得ることができる
。It represents the difference in b, and the zero-crossing points are clear as can be seen from the figure. The distance between the peaks and troughs of waveform C is equal to 1/2 of the reflector pitch, and for floppy disk drivers, etc., it is 5" in shape, '285 grn or 3.5".
The weight is 188 gm. Here, when the movable object moves at 188 gm, the output of the differential amplifier changes from peak to valley, crossing the zero cross point, so in order to obtain Igm resolution, the S/N of the differential light receiving output is The ratio is 45.5d
Bt: 18871) or more is sufficient. in general,
If an LED is used as the light emitting element and a silicon photodiode or the like is used as the light receiving element, the S/N ratio can be reliably achieved at 80 dB or more. This is because the frequency band of the above is narrow. Therefore, the S/N ratio in the present invention can easily be 50 dB even when the fluctuation component is taken into consideration.
（発明の効果 ）
以上、説明したように、本発明によれば、ＩＩＬ＋ｏ以
下の位置情報の分解能を有することができ、構造が簡単
でかつ、反射板の材質が任意のもので限定されない新し
いエンコーダを提供できる。(Effects of the Invention) As explained above, according to the present invention, a new encoder can have a resolution of position information of IIL+o or less, has a simple structure, and is not limited to any material for the reflector. can be provided.
第１図は本発明の一実施例を示す構成図、第２図は本発
明の一実施例における可動物体の移動に対する２個の受
光素子及び差動増幅器の出力特性を示す図である。
１０−−ｍｍ動物体、１１−ｍ−反射板、１２−ｍ−固
定スリット、１３−ｍ−窓、１４、１５−ｍ−発光素子
、１６．１７−”−受光素子、１８−ｍ−差動増幅器、
１９−ｍ−入力端子、２０−ｍ−出力端子、 ２１−
ｍ−矢印。
特許出願人
ティーディーケイ株式会社
特許出願代理人
弁理士 山本恵−
第１図
８FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing output characteristics of two light receiving elements and a differential amplifier with respect to movement of a movable object in one embodiment of the present invention. 10-mm moving object, 11-m-reflector, 12-m-fixed slit, 13-m-window, 14, 15-m-light emitting element, 16.17-"-light receiving element, 18-m-difference dynamic amplifier,
19-m-input terminal, 20-m-output terminal, 21-
m - arrow. Patent applicant TDC Co., Ltd. Patent application agent Megumi Yamamoto - Figure 1 8
Claims (1)
列に配列された複数の反射板をもつ第１の基板と、前記
移動方向に互いに１／２ピツチずれ２列に配列され前記
反射板と対応する窓をもつ第２の基板と、第２の基板の
窓を通して第１の基板の前記反射板の各列を照射する２
個の発光素子と、該発光素子から放射された光が前記反
射板により反射されたことによる反射光を受光する２個
の受光素子とを有し、２個の該受光素子から得られる各
々の電気信号の差分に基づき前記反射板と前記窓の相対
的位置を位置情報としてアナログ的に検知することを特
徴とする光学式エンコーダ。movable and 1/2 pitch apart from each other in the direction of movement 2
a first substrate having a plurality of reflective plates arranged in rows; a second substrate having windows corresponding to the reflective plates arranged in two rows shifted by 1/2 pitch from each other in the moving direction; 2. Irradiating each row of said reflectors of the first substrate through a window in the substrate.
light emitting elements, and two light receiving elements that receive reflected light caused by the light emitted from the light emitting elements being reflected by the reflecting plate, and each of the light receiving elements obtained from the two light receiving elements An optical encoder characterized in that the relative position of the reflector and the window is detected as position information in an analog manner based on a difference in electrical signals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7833984A JPS60222717A (en) | 1984-04-20 | 1984-04-20 | Optical encoder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7833984A JPS60222717A (en) | 1984-04-20 | 1984-04-20 | Optical encoder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS60222717A true JPS60222717A (en) | 1985-11-07 |
Family
ID=13659223
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7833984A Pending JPS60222717A (en) | 1984-04-20 | 1984-04-20 | Optical encoder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60222717A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62259893A (en) * | 1986-04-30 | 1987-11-12 | 凸版印刷株式会社 | Defector for page missing and erratic pagination of bookbinding collator |
-
1984
- 1984-04-20 JP JP7833984A patent/JPS60222717A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62259893A (en) * | 1986-04-30 | 1987-11-12 | 凸版印刷株式会社 | Defector for page missing and erratic pagination of bookbinding collator |
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