JPS6329320B2 - - Google Patents
Info
- Publication number
- JPS6329320B2 JPS6329320B2 JP54077502A JP7750279A JPS6329320B2 JP S6329320 B2 JPS6329320 B2 JP S6329320B2 JP 54077502 A JP54077502 A JP 54077502A JP 7750279 A JP7750279 A JP 7750279A JP S6329320 B2 JPS6329320 B2 JP S6329320B2
- Authority
- JP
- Japan
- Prior art keywords
- optical
- light
- code plate
- optical fiber
- transmitted
- 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.)
- Expired
Links
- 230000003287 optical effect Effects 0.000 claims description 51
- 239000013307 optical fiber Substances 0.000 claims description 18
- 238000005259 measurement Methods 0.000 claims description 11
- 238000006073 displacement reaction Methods 0.000 claims description 8
- 230000005540 biological transmission Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000000835 fiber Substances 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 2
- 230000005856 abnormality Effects 0.000 description 1
- 238000000295 emission spectrum Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Description
【発明の詳細な説明】
本発明は機械的な変位を符号化された光信号に
変換する光符号板を備えた光学的計測システムに
関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical metrology system with an optical code plate that converts mechanical displacements into encoded optical signals.
石油化学プラントなど、本質安全防爆性を必要
とするプラントの開閉弁などを制御監視する手段
として、光フアイバを用いた光学的計測は望まし
い特長を有する。 Optical measurement using optical fibers has desirable features as a means to control and monitor on-off valves in plants that require intrinsically safe explosion-proof properties, such as petrochemical plants.
ところで従来機械的な変位を符号化された光信
号に変換する光符号板を備えた光学的計測システ
ムとして第１図の如きものが知られている。すな
わちこのシステムは複数の光源１の光をフアイバ
２によつてコリメート光学系３に導びき、各コリ
メート光学系の出力光を光符号板４の各ビツトに
導びいて、その透過光を集束光学系５で集光し
て、フアイバ６を介して光検出器７に加えるよう
に構成されている。そして光符号板４が機械的変
位によつて図中矢印方向に変位することに応じて
変化する光符号板４の透過光量を光検出器７で検
出するようにされている。 By the way, as a conventional optical measurement system equipped with an optical code plate that converts mechanical displacement into a coded optical signal, there is a system as shown in FIG. 1. That is, this system guides light from a plurality of light sources 1 to a collimating optical system 3 through fibers 2, guides the output light of each collimating optical system to each bit of an optical code plate 4, and converts the transmitted light into a focusing optical system. The light is collected by a system 5 and applied to a photodetector 7 via a fiber 6. A photodetector 7 detects the amount of light transmitted through the optical code plate 4, which changes as the optical code plate 4 is mechanically displaced in the direction of the arrow in the figure.
しかるにこのシステムにおける光符号板では、
変位を符号化するに使用するビツト数だけの光フ
アイバを必要とするため、大規模なプラント計測
では伝送距離が長くなることもあつて使用する光
フアイバ量は莫大なものとなる。また高精度化の
ためにはビツト数を増やす必要があり、それに応
じてビツト数だけの光学系を必要とするため、小
形化が難しい。 However, in the optical code board in this system,
Since as many optical fibers as the number of bits used to encode the displacement are required, in large-scale plant measurements, the transmission distance becomes long and the amount of optical fibers used becomes enormous. Furthermore, in order to achieve high precision, it is necessary to increase the number of bits, and accordingly, an optical system corresponding to the number of bits is required, making it difficult to miniaturize.
本発明は上記の如き従来の問題をなくすために
なされたもので、光フアイバの使用量を減少で
き、かつシステムの簡素化を図り得る光学的計測
システムを提供することを目的とする。 The present invention has been made in order to eliminate the above-mentioned conventional problems, and an object of the present invention is to provide an optical measurement system which can reduce the amount of optical fiber used and which can simplify the system.
以下図面を参照しながら本発明を詳細に説明す
る。 The present invention will be described in detail below with reference to the drawings.
第２図は本発明の一実施例を示す図である。図
中１１は光源で、波長λ1〜λ4まで含む広い発光ス
ペクトルを有する発光ダイオードないしは個別の
発光波長λ1、λ2、λ3、λ4を有する光源を波長多重
合波器で合成したものである。この光源１１によ
る光は光フアイバケーブル１２によつてプラント
の計測点に導かれる。１３はコリメート光学系
で、光フアイバケーブル１２からの光束を所定の
平行光束に変換する。コリメート光学系１３で得
られた平行光は次に光符号板１４に導かれ、その
透過光束は集束光学系１５で集光された後出力光
フアイバケーブル１６を介して光学的分配器１８
に加えられる。光学的分配器１８は光符号板１４
のビツト毎に対応した波長の光を分離して光検出
器１７に導入される。 FIG. 2 is a diagram showing an embodiment of the present invention. In the figure, reference numeral 11 denotes a light source, which is a light emitting diode with a wide emission spectrum including wavelengths λ 1 to λ 4 or a light source with individual emission wavelengths λ 1 , λ 2 , λ 3 , and λ 4 combined by a wavelength multiplexer. It is something. Light from this light source 11 is guided to a measurement point in the plant via an optical fiber cable 12. A collimating optical system 13 converts the light beam from the optical fiber cable 12 into a predetermined parallel light beam. The parallel light obtained by the collimating optical system 13 is then guided to the optical code plate 14, and the transmitted light beam is condensed by the focusing optical system 15 and then sent to the optical distributor 18 via the output optical fiber cable 16.
added to. The optical distributor 18 is connected to the optical code plate 14
Light of a wavelength corresponding to each bit is separated and introduced into a photodetector 17.
ここで光符号板１４は本実施例ではビツト数４
に対応して４枚の干渉フイルタで構成されてい
る。図中黒くぬられた部分は各々の波長に対して
のみ不透明である領域である。また、各干渉フイ
ルタの透過率の波長依存性は第３図に示されてい
る。 Here, the optical code plate 14 has a bit number of 4 in this embodiment.
It is composed of four interference filters corresponding to the following. The black areas in the figure are regions that are opaque only to each wavelength. Further, the wavelength dependence of the transmittance of each interference filter is shown in FIG.
この光符号板１４が図示矢印方向に変位するこ
とによつて第１の波長λ1に対応する干渉フイルタ
はフルレンジの1/2を閾値として透過出力有り、
無しの信号を光検出器１７に出すことになり、以
下同様にして、第２の波長λ2に対応する干渉フイ
ルタは1/4、第３の波長λ3に対応する干渉フイル
タは1/8、第４の波長λ4に対応する干渉フイルタ
は1/16の閾値で透過光の有無の信号を送ることに
なるため、結果的には光検出器１７は４ビツトの
２進符号として機械的変位を検出できることにな
る。 By displacing this optical code plate 14 in the direction of the arrow shown in the figure, the interference filter corresponding to the first wavelength λ 1 has a transmitted output with 1/2 of the full range as a threshold,
In the same way, the interference filter corresponding to the second wavelength λ 2 is 1/4, and the interference filter corresponding to the third wavelength λ 3 is 1/8. , the interference filter corresponding to the fourth wavelength λ 4 sends a signal indicating the presence or absence of transmitted light at a threshold of 1/16, and as a result, the photodetector 17 mechanically transmits a signal as a 4-bit binary code. This means that displacement can be detected.
尚、本発明における光符号板を円板状として扇
状の分割を行なえば、回転角の計測も可能であ
る。 Incidentally, if the optical code plate in the present invention is made into a disk shape and divided into fan shapes, it is also possible to measure the rotation angle.
本発明による機械的変位、回転角などの光学的
計測システムでは、光フアイバからの光束を平行
光束に変換するコリメート光学系と平行光束を出
力光フアイバに結合させる集束光学系との間に、
複数の干渉フイルタを光軸上に順に並べた光符号
板を介在させ、各干渉フイルタは特定の波長毎に
透明、不透明の複数の領域に空間的に分割した構
成となつている。従つて本発明によれば、符号化
するに使用するビツト数が増えても光フアイバの
数は一定であるため、従来のシステムに比較し、
光フアイバケーブルの使用量が著しく減少でき
る。このことは大規模なプラント計測において伝
送距離が長くなる場合には特に有効である。この
ようにしてビツト数が増大してもコリメート光学
系や集束光学系の増大をまねかないためシステム
の小形化を図ることができる。 In the optical measurement system for measuring mechanical displacement, rotation angle, etc. according to the present invention, between a collimating optical system that converts a light beam from an optical fiber into a parallel light beam and a focusing optical system that couples the parallel light beam to an output optical fiber,
An optical code plate in which a plurality of interference filters are arranged in order on the optical axis is interposed, and each interference filter is spatially divided into a plurality of transparent and opaque regions for each specific wavelength. Therefore, according to the present invention, the number of optical fibers remains constant even as the number of bits used for encoding increases, so compared to conventional systems,
The amount of fiber optic cable used can be significantly reduced. This is particularly effective when the transmission distance becomes long in large-scale plant measurements. In this way, even if the number of bits increases, the collimating optical system and the focusing optical system will not increase, so the system can be made more compact.
さらに本発明では光源１１の発光波長を時間系
列として切換え、光符号板１４の透過波長特性を
光学的分波器なしに広波長域の光の量を検出する
光検出器１７を用いて検出するようにしている。
このように発光波長を時間的に切換えることによ
り、同時に複数波長を発光する場合に比らべ、プ
リズム、光学的分波器等の波長分離機構が不要と
なりシステムの小形化をさらに図ることができ
る。またこの方式において、更に光フアイバケー
ブルの断線などを監視する手段をとり入れること
が望まれる場合は、波長λ1〜λ4に加えて別の波長
λ0を使い、この波長λ0を光符号器１４のとり得る
条件の全てに対して透過するように選択して、こ
の受信出力を監視するようにすれば良い。第４図
は発光波長を時間的系列として切換える様子と、
さらにこの時間系列の最初に上記監視用光パルス
λ0を挿入した様子を示したもので、第４図ａは送
信出力、第４図ｂは受信出力を示している。第４
図ｂにおいてλ1〜λ4は１もしくは０の値をとり、
またλ0は光フアイバケーブルの断線などの異常が
発生すれば０となる。 Furthermore, in the present invention, the emission wavelength of the light source 11 is switched in time series, and the transmission wavelength characteristics of the optical code plate 14 are detected using the photodetector 17 that detects the amount of light in a wide wavelength range without an optical demultiplexer. That's what I do.
By temporally switching the emission wavelength in this way, compared to the case where multiple wavelengths are emitted at the same time, wavelength separation mechanisms such as prisms and optical demultiplexers are not required, making it possible to further downsize the system. . In addition, in this system, if it is desired to incorporate a means for monitoring breaks in the optical fiber cable, another wavelength λ 0 is used in addition to the wavelengths λ 1 to λ 4 , and this wavelength λ 0 is transmitted to the optical encoder. The reception output may be monitored by selecting the signal to be transparent to all of the 14 possible conditions. Figure 4 shows how the emission wavelength is switched in a time series,
Furthermore, the above-mentioned monitoring optical pulse λ 0 is inserted at the beginning of this time series, and FIG. 4a shows the transmission output, and FIG. 4b shows the reception output. Fourth
In figure b, λ 1 to λ 4 take a value of 1 or 0,
Further, λ 0 becomes 0 if an abnormality such as a break in the optical fiber cable occurs.
以上の説明では機械的変化や回転角の変化を計
測する場合を例にあげたが、これらは計測の基本
量の１つであるので、その適用は広範囲で、例え
ば液面計、風向計、圧力計などにも活用できるこ
とは言うまでもない。 In the above explanation, we took examples of measuring mechanical changes and changes in rotation angle, but since these are one of the basic quantities of measurement, their application is wide-ranging, such as liquid level gauges, wind vanes, etc. Needless to say, it can also be used as a pressure gauge.
第１図は光符号板を用いた従来の光学的計測シ
ステムの構成図、第２図は本発明の一実施例を示
す構成図、第３図は本発明における光符号板の波
長特性の説明図、第４図ａ，ｂは本発明の変形例
を説明するための図である。
１１……光源、１２，１６……光フアイバケー
ブル、１３……コリメート光学系、１４……光符
号板、１５……集束光学系、１７……光検出器、
１８……光学的分波器。
Fig. 1 is a block diagram of a conventional optical measurement system using an optical code plate, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. 3 is an explanation of the wavelength characteristics of the optical code plate in the present invention. 4A and 4B are diagrams for explaining a modification of the present invention. 11... Light source, 12, 16... Optical fiber cable, 13... Collimating optical system, 14... Optical code plate, 15... Focusing optical system, 17... Photo detector,
18...Optical demultiplexer.
Claims (1)
源からの光を伝送する光フアイバと、この光フア
イバによつて伝送された光の光軸上に順に並べら
れ、変位に基づいて前記各発光波長に対する透明
及び不透明領域を形成する複数の干渉フイルタか
らなり、前記変位に基づいて前記光フアイバから
の光を２進符号化する光符号板と、この光符号板
を透過した光を伝送する光フアイバと、この光フ
アイバによつて伝送された光を検出する光検出器
とからなり、前記光源の発光波長を時間的に切換
えることにより、前記光検出器から時系列出力を
得るようにしたことを特徴とする光学的計測シス
テム。 ２ 前記複数の発光波長の一つは、前記変位にか
かわらず前記干渉フイルタの全てを透過すること
を特徴とする特許請求の範囲第１項記載の光学的
計測システム。[Scope of Claims] 1. A light source that emits light of a plurality of emission wavelengths, an optical fiber that transmits the light from the light source, and a light source that is arranged in order on the optical axis of the light transmitted by the optical fiber, and that has a displacement an optical code plate that binary encodes the light from the optical fiber based on the displacement; and an optical code plate that transmits light through the optical code plate. It consists of an optical fiber that transmits the transmitted light, and a photodetector that detects the light transmitted by the optical fiber, and by temporally switching the emission wavelength of the light source, the photodetector outputs a time series output. An optical measurement system characterized in that it obtains. 2. The optical measurement system according to claim 1, wherein one of the plurality of emission wavelengths is transmitted through all of the interference filters regardless of the displacement.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7750279A JPS562094A (en) | 1979-06-21 | 1979-06-21 | Optical measuring system using optical code plate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7750279A JPS562094A (en) | 1979-06-21 | 1979-06-21 | Optical measuring system using optical code plate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS562094A JPS562094A (en) | 1981-01-10 |
| JPS6329320B2 true JPS6329320B2 (en) | 1988-06-13 |
Family
ID=13635736
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7750279A Granted JPS562094A (en) | 1979-06-21 | 1979-06-21 | Optical measuring system using optical code plate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS562094A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0627216B2 (en) * | 1984-12-11 | 1994-04-13 | ジャパンゴアテックス株式会社 | Stretchable moisture-permeable waterproof film for clothing |
| JPH089668B2 (en) * | 1986-10-14 | 1996-01-31 | 東レ株式会社 | Hydrophilized film and method for producing the same |
| JPH09196911A (en) | 1996-01-19 | 1997-07-31 | Fuji Photo Film Co Ltd | Blood filter unit |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52104004A (en) * | 1976-02-27 | 1977-09-01 | Yokogawa Hokushin Electric Corp | Signal transmission apparatus |
-
1979
- 1979-06-21 JP JP7750279A patent/JPS562094A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52104004A (en) * | 1976-02-27 | 1977-09-01 | Yokogawa Hokushin Electric Corp | Signal transmission apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS562094A (en) | 1981-01-10 |
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