JPS58191906A - Length measuring method using reference ruler - Google Patents
Length measuring method using reference rulerInfo
- Publication number
- JPS58191906A JPS58191906A JP7480682A JP7480682A JPS58191906A JP S58191906 A JPS58191906 A JP S58191906A JP 7480682 A JP7480682 A JP 7480682A JP 7480682 A JP7480682 A JP 7480682A JP S58191906 A JPS58191906 A JP S58191906A
- Authority
- JP
- Japan
- Prior art keywords
- measuring
- standard
- length
- diffraction grating
- measurement
- 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
- 238000000034 method Methods 0.000 title claims description 14
- 238000005259 measurement Methods 0.000 claims abstract description 35
- 238000000691 measurement method Methods 0.000 claims description 5
- 238000010586 diagram Methods 0.000 description 8
- 230000003287 optical effect Effects 0.000 description 6
- 239000000696 magnetic material Substances 0.000 description 2
- 230000005389 magnetism Effects 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000000609 electron-beam lithography Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000007740 vapor deposition Methods 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
- G01D5/38—Forming the light into pulses by diffraction gratings
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は、有限長の基準尺を使用し、この基準尺の長さ
以上の移動量を計測するようにした基準尺を用いた測長
方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a length measuring method using a finite-length standard, which measures a movement amount greater than the length of the standard.
長さや位置計測の分野では、従来から純機械的な物差し
、ノギス、マイクロメータ等を用いて人間の目による計
測は依然として行われているが、ｐＬｍ単位を問題とす
る所謂精密計測の領域ではこれらの測定用具はその用を
なさない。近年、測定機器の電子化が進み、電子回路と
共に光Φ磁気等の技術を用いた測定装置が開発され、加
工・検査に多用されている。光を用いる測定装置の一例
としては、レーザー光の波長を基準とした光波干渉測長
器が知られている。この測長器の精度は、現在の工業水
準の要求に十分対応できるものであるが、むしろ過剰な
精度を有するとも云え価格的にも高価である。また、磁
気を用いた方式として、帯状又は棒状の磁性体に予め寸
法の基準としての磁気パターンを記録しておき、この磁
気パターンと磁気ヘッドとの相互の位置関係を求める一
磁−気スケールも知られている。この方式は磁性体に記
録できる基準パターンのピッチにより精度が決定され、
安定に記録し得るピッチは５Ｂｍ−１０１ｉｍのピッチ
であり、測定精度は光波干渉測長器と比較して実用上２
桁程度精度が低い、そこで、光波干渉測長器と磁気スケ
ールとの中間的な精度を有する測長器を工作機等に付設
することが要求され、このための基準として数＃Ｌｍ程
度のピッチを持つ光学的回折格子を用いて、精度的及び
価格的に前記両者の中間的な測長装置の実用化が進んで
いる。この場合に基準となる回折格子ｌは、第１図に示
すように、ガラス又は金属板に機械的なルーリングエン
ジン、光学的リングラフィ、電子ビームリソグラフィ等
を用いて極細の格子線２が密集して並列するように造ら
れている。しかし、この回折格子１の製造可能な長さ寸
法は高々１００〜２００ｍｍ程度であり、光波干渉計又
は磁気的な測定装置が共に１ｍを超す測定範囲を有する
のに対して大きな弱点となっている。In the field of length and position measurement, measurements are still performed by the human eye using purely mechanical rulers, calipers, micrometers, etc., but in the field of so-called precision measurement where pLm units are the issue, these methods are Measuring tools are of no use. In recent years, the digitization of measuring instruments has progressed, and measuring devices that use technologies such as optical Φ magnetism as well as electronic circuits have been developed and are often used for processing and inspection. As an example of a measuring device that uses light, a light wave interference length measuring device that uses the wavelength of laser light as a reference is known. Although the accuracy of this length measuring device is sufficient to meet the requirements of the current industrial level, it can be said that it has excessive accuracy and is expensive. In addition, as a method using magnetism, there is also a magnetic scale in which a magnetic pattern is recorded in advance on a band-shaped or rod-shaped magnetic material as a reference for dimensions, and the mutual positional relationship between this magnetic pattern and a magnetic head is determined. Are known. The accuracy of this method is determined by the pitch of the reference pattern that can be recorded on the magnetic material.
The pitch that can be stably recorded is 5Bm-101im, and the measurement accuracy is practically 2 times higher than that of a light wave interferometric length measuring device.
Therefore, it is required to attach a length measuring device with an accuracy intermediate between a light wave interferometric length measuring device and a magnetic scale to machine tools, and the standard for this is a pitch of several #Lm. Using optical diffraction gratings, length measuring devices that are intermediate between the two in terms of accuracy and cost are being put into practical use. In this case, the reference diffraction grating l is made by densely forming ultrafine grating lines 2 on a glass or metal plate using a mechanical ruling engine, optical phosphorography, electron beam lithography, etc., as shown in Figure 1. They are designed to be placed in parallel. However, the length dimension that can be manufactured for this diffraction grating 1 is about 100 to 200 mm at most, which is a major weakness since both optical interferometers and magnetic measurement devices have measurement ranges exceeding 1 m. .
本発明の目的は、基準尺よりも十分に長い所要の測定範
囲が得られ精度的、経済的に有利な基準尺を用いた測長
方法を提供することにあり、その要旨は、相対的に移動
する２物体の一方に基準量を有する有限長の基準尺を設
置し、他方に前記基準尺との相対的位置関係を前記基準
量を単位として求める測定ヘッド部を設け、前記２物体
の相対的移動方向に前記基準尺の有効長以内の間隔を鐙
いて複数個の前記測定ヘッド部を配置し、別に設けた位
置検知器により適用すべき測定ヘッド部を選択し、測定
へ−２ド部の基準量を単位とする出力を計数して、２物
体間の相対的移動量を測定することを特徴とする方法で
ある。An object of the present invention is to provide a length measurement method using a standard that can obtain a required measurement range that is sufficiently longer than the standard and is advantageous in terms of accuracy and economy. A finite length standard having a reference amount is installed on one of the two moving objects, and a measuring head section is provided on the other side to determine the relative positional relationship with the standard using the reference amount as a unit. A plurality of measuring heads are arranged at intervals within the effective length of the reference standard in the direction of movement of the target, and a separately provided position detector selects the measuring head to be applied, and the process proceeds to measurement. This method is characterized in that the amount of relative movement between two objects is measured by counting the output in units of a reference amount.
第２図は本発明に係る方法の原理的説明図であり、複数
個の測定ヘッド部３１．３ｊ、３ｋ、・・・が間隔りで
等間隔に固定的に配置されている。基準尺となる回折格
子ｌの有効長は、前記間隔夕よりも稍々長い寸法を有し
、回折格子１は測定ヘッド部３１．３ｊ、・拳Φの配列
方向に沿って測定ヘッド部３１．３ｊ、Φ・・内を通過
して、一点鎖線で示すように移動できるようになってい
る。回折格子１は光透過材より成り、更に支持部材４が
附設されていて、この支持部材４には例えばピンホール
５が設けられ、測定ヘッド部３と同様に間隔ρで配置さ
れた投受光器から成る複数個の位置検知器６により支持
部材４の位置を検知し得るようにされている。FIG. 2 is a diagram illustrating the principle of the method according to the present invention, in which a plurality of measurement head sections 31.3j, 3k, . . . are fixedly arranged at equal intervals. The effective length of the diffraction grating l serving as a reference standard has a slightly longer dimension than the above-mentioned interval length, and the diffraction grating 1 is attached to the measuring head parts 31. 3j, Φ..., and can move as shown by the dashed line. The diffraction grating 1 is made of a light-transmitting material, and is further provided with a support member 4, which is provided with, for example, a pinhole 5, and has light emitters and receivers arranged at an interval ρ in the same way as the measurement head 3. The position of the support member 4 can be detected by a plurality of position detectors 6 consisting of.
第３図は測定ヘッド部３の具体的な構成図を示し、回折
格子ｌの手前側に光源７．２個の検出器８ａ、８ｂ、レ
ンズ系９、偏向鏡ｌＯａ、ｌＯｂ、偏光ビームスプリッ
タ１１が配置され、回折格子ｌの反対側にダハプリズム
１２ａ、１２ｂ、位相差板１３ａ、１３ｂが配置されて
いる。光源７は発光ダイオードや半導体レーザー等の半
導体発光素子であり、レンズ系９は光源７から射出され
る光線りをほぼ平行光束にするためのものであって、偏
向鏡１０ａ、１０ｂは偏向鏡１０ａへの入射光と、偏向
鏡１０ｂからの射出光とが平行になるように、これらの
相対角度は９０度に設定されている。また、位相差板１
３ａ、１３ｂは光源７からの直線偏光を回折格子ｌに再
入射するときに、右廻り及び左廻りの円偏光にする働き
をしている。FIG. 3 shows a specific configuration diagram of the measurement head section 3, which includes a light source 7, two detectors 8a, 8b, a lens system 9, deflection mirrors lOa, lOb, and a polarizing beam splitter 11 in front of the diffraction grating l. are arranged, and roof prisms 12a, 12b and retardation plates 13a, 13b are arranged on the opposite side of the diffraction grating l. The light source 7 is a semiconductor light emitting element such as a light emitting diode or a semiconductor laser, the lens system 9 is for converting the light beam emitted from the light source 7 into a substantially parallel beam, and the deflecting mirrors 10a and 10b are the deflecting mirror 10a. The relative angle between these is set to 90 degrees so that the incident light and the emitted light from the deflection mirror 10b are parallel to each other. In addition, the retardation plate 1
3a and 13b serve to convert the linearly polarized light from the light source 7 into clockwise and counterclockwise circularly polarized light when it re-enters the diffraction grating l.
従って、光源７から発光された光線りはレンズ系９で平
行光束とされ、偏向鏡１０ａにより回折格子ｌの点Ａに
入射する。そして、回折格子１により回折され、回折格
子ｌの位相δが回折波面に加算され、入射光の初期位相
をＯとすると回折波の位相項はｅｘｐ（ｉ（ωｔ＋ｍδ
））となる。ここでｍは回折次数であり、例えば＋１次
項と−１次項はそれぞれｅｘｐ（ｉ（ωを十δ））、
ｅｘｐ（ｉ（ωｔ−δ））となり、＋１次項である光線
Ｌｌ、゛−１次項である光線Ｌ２はそれぞれ位相差板１
３ａ、１３ｂを経由しコーナーキューブプリズム又は図
示のダハプリズム１２ａ、１２ｂに入射する。光線Ｌ１
． Ｌ２はダハプリズム１２ａ、１２ｂで入射方向と平
行方向に反射され、位相差板１３ａ、１３ｂにより右廻
り及び左廻りの円偏光にされ、回折格ｆ１の点ＡとＸ方
向に異なる点Ｂにおいて再び回折され、更に偏向鏡ｆｏ
ｂを介して偏光ビームスプリッタ１１に入射する。この
偏光ビームスプリッタ１１に入射した右廻り及び左廻り
の円偏光特性を有する光線Ｌ１．Ｌ２は、偏光ビームス
プリッタ１１を透過及び反射する。透過光及び反射光は
それぞれ直線偏光になり、Ｍいに干渉し合って検出器８
ａ及び８ｂに入射することになる。Therefore, the light beam emitted from the light source 7 is made into a parallel beam by the lens system 9, and is incident on the point A of the diffraction grating l by the deflection mirror 10a. Then, it is diffracted by the diffraction grating 1, and the phase δ of the diffraction grating l is added to the diffraction wavefront. If the initial phase of the incident light is O, the phase term of the diffraction wave is exp(i(ωt+mδ
)) becomes. Here, m is the diffraction order, for example, the +1st order term and the -1st order term are respectively exp(i(ω = 10δ)),
exp(i(ωt-δ)), and the light ray Ll, which is the +1st order term, and the light ray L2, which is the -1st order term, are the retardation plate 1.
3a and 13b, the light enters the corner cube prism or the illustrated roof prism 12a and 12b. Ray L1
．． L2 is reflected by the roof prisms 12a and 12b in a direction parallel to the incident direction, converted into clockwise and counterclockwise circularly polarized light by the retardation plates 13a and 13b, and diffracted again at a point B on the diffraction grating f1 that is different from point A in the X direction. and further a deflecting mirror fo
The light enters the polarizing beam splitter 11 via the beam b. The light beam L1. which is incident on the polarizing beam splitter 11 and has clockwise and counterclockwise circular polarization characteristics. L2 transmits and reflects the polarizing beam splitter 11. The transmitted light and reflected light each become linearly polarized light, which interferes with each other and reaches the detector 8.
It will be incident on a and 8b.
検出器８ａ及び８ｂは２つの円偏光の直交成分を干渉光
強度として検出するため、回折格子ｌが移動した場合の
検出器８ａ、８ｂの出力Ｒ，Ｓは、第４図（ａ） 、
（ｂ）に示すように９０度の位相差を有する。この２つ
の信号Ｒ，Ｓを一定しヘルの基に（ｃ） 、 （ｄ）に
示すように図示しない回路によってそれぞれ二値化し、
その立上りと立下りのタイミングで（ｅ）に示すように
パルスを発生させ、そのパルス数を計数することによっ
て回折格ｆｌの移動閂を計測できる。また、この計数時
には回折格子１の移動方向を考慮して、加算又は減算か
を決定すればよい。この場合は、回折格子１の１周期の
移動により干渉縞の出力は４Ｎ周期の移動となり、その
出力からパルスを計数すると１６個のパルスを得ること
になる。Since the detectors 8a and 8b detect orthogonal components of two circularly polarized lights as interference light intensity, the outputs R and S of the detectors 8a and 8b when the diffraction grating l moves are as shown in FIG. 4(a),
As shown in (b), there is a phase difference of 90 degrees. These two signals R and S are kept constant and are respectively binarized by circuits (not shown) as shown in (c) and (d) based on Hell.
The moving bar of the diffraction grating fl can be measured by generating pulses as shown in (e) at the rising and falling timings and counting the number of pulses. Further, during this counting, it is sufficient to decide whether to add or subtract by considering the moving direction of the diffraction grating 1. In this case, when the diffraction grating 1 moves by one period, the output of the interference fringes moves by 4N periods, and if the pulses are counted from the output, 16 pulses will be obtained.
第５図はその（ａ） 、 （ｂ）に示す２つの信号Ｒ１
Ｓを、更に（ｃ） 、 （ｄ）に示すように加算及び減
算をして、４５度ずつ位相の異なった信号Ｒ＋Ｓ、Ｒ−
３を作成し、（ｅ）〜（ｈ）に示すように二値化して１
回折格子ｌの１周期の移動によって（１）に示すような
３２個のパルスを発生するようにした場合の例を示して
いる。また、これらの信号を確実に処理するためには、
光量の変動及び回折効率の変動等を考慮する必要がある
ため、第３図に示すように、一方のダハプリズム１２ｂ
の頂点から回折光を取り出し、その光量をライトガイド
１４を介して検出器１５で検出し信号処理に利用しても
よい。Figure 5 shows the two signals R1 shown in (a) and (b).
S is further added and subtracted as shown in (c) and (d) to obtain signals R+S and R- with phases different by 45 degrees.
3, and binarize it as shown in (e) to (h) to create 1.
An example is shown in which 32 pulses as shown in (1) are generated by one period of movement of the diffraction grating l. In addition, in order to reliably process these signals,
Since it is necessary to take into account variations in light amount and diffraction efficiency, one of the roof prisms 12b is
The diffracted light may be taken out from the vertex of the diffracted light, and the amount of light may be detected by the detector 15 via the light guide 14 and used for signal processing.
なお、第６図に示すＡｌ１１定ヘッド部３は、前述の第
３図の実施例では透過を応用した場合に対して１回折格
子１を反射型格子にした場合であり、第３図と同一の符
号は同一の部材を示している。Note that the Al11 constant head section 3 shown in FIG. 6 is the same as that in FIG. The symbols indicate the same members.
回折格子１を反射型にした場合は、光学系の占めるスペ
ースを小さくすることが可能となり、各部材が回折格子
ｌに対して一方向に配置されるために取り扱いが容易と
なる利点がある。When the diffraction grating 1 is of a reflective type, the space occupied by the optical system can be reduced, and each member is arranged in one direction with respect to the diffraction grating 1, which has the advantage of ease of handling.
ここで第２図において、回折格子１が移動すると、その
ときの回折格子ｌが位置する測定ヘッド部３１．３ｊ、
３ｋ、・・番からは第７７に示すようなパルスＰｉ、
Ｐｊ、 Ｐｋ、・・争が得られる。距離ｇの倍数距＃ｇ
、２ρ、３ｇ、・・・イ・１近では、２個の測定ヘッド
部３により回折格子ｌの両端が計測されるために、パル
スが重複して発生される。この場合、これらのパルスが
例えば距＃ｇにおけるように詩間的に重なり合っていれ
ば計数誤差は生しないが、距＃２９のようにパルスが若
干ずれて発生されると誤計数となり、測定誤差を招来す
ることになる。このように回折格子ｌを２個の測定ヘッ
ド部３が同時に検出する場合には、位置検知器６により
択一的に測定ヘッド部３を選択し、選択された測定ヘッ
ド部３のパルス数を計数するようにすればよい。この測
定ヘッド部３の切換えは、各位置検知器６及び測定ヘッ
ド部３の出力信号の組合わせによる論理回路により容易
に実現できるところである。従って、回折格子ｌの移動
距離は、測定ヘッド部３からの出力パルス数を回折格子
１の移動方向を検出した信号を基に、加算又は減算する
ことにより求められることになる。Here, in FIG. 2, when the diffraction grating 1 moves, the measurement head section 31.3j, where the diffraction grating l is located at that time,
From numbers 3k, . . . , pulses Pi as shown in number 77,
Pj, Pk... dispute is obtained. Distance g multiple distance #g
, 2ρ, 3g, . In this case, if these pulses overlap each other, for example at distance #g, no counting error will occur, but if the pulses are generated with a slight deviation, as at distance #29, an erroneous count will occur and measurement error will occur. will be invited. In this way, when two measurement heads 3 simultaneously detect the diffraction grating l, the position detector 6 selectively selects the measurement head 3, and the number of pulses of the selected measurement head 3 is determined. Just count it. This switching of the measuring head section 3 can be easily realized by a logic circuit based on a combination of the output signals of each position detector 6 and the measuring head section 3. Therefore, the moving distance of the diffraction grating 1 is determined by adding or subtracting the number of output pulses from the measurement head section 3 based on the signal that detects the moving direction of the diffraction grating 1.
第８図は他の実施例であり、前述の実施例が１個の回折
格子ｌを複数個の測定ヘッド部３１．３ｊ、３に、Φ・
・に沿って移動させたのに対し、複数個の回折格子１ｉ
、ｌｊ、ｌｋ、・・・を等間隔に配置し、回折格子１の
有効長よりも短い間隔に保持部１６により保持した２個
の測定ヘッド部３ｕ、３ｖを、回折格子１１．１ｊ、１
に、−・・に対して移動するようにしている。この場合
は、２個の測定ヘッド部３ｕ、３ｖの少なくとも１個が
、何れかの回折格子１ｉ、ｌｊ、ｌｋ、・拳・を検出で
きるので、位置検知器により測定ヘッド部３ｕ、３ｖの
動きを検出し、測定ヘッド部３ｕ、３ｖの何れかを選択
し、移動量は選択された測定へフド部３から得られる出
力パルスを計数すればよい。。FIG. 8 shows another embodiment, in which one diffraction grating l is connected to a plurality of measurement heads 31.3j, 3, and Φ.
・In contrast, multiple diffraction gratings 1i
, lj, lk, .
, so that it moves relative to -... In this case, since at least one of the two measurement heads 3u, 3v can detect any of the diffraction gratings 1i, lj, lk, fist, the movement of the measurement heads 3u, 3v can be detected by the position detector. is detected, one of the measurement head parts 3u and 3v is selected, and the amount of movement can be determined by counting the output pulses obtained from the lid part 3 for the selected measurement. .
上述の幾つかの実施例においては、測定ヘッド部３を回
折格子ｌによる回折光の干渉を利用し、回折光は回折格
子ｌを２回に捗り通過又は反射し、高精度の測定値が得
られるようになっているが、回折格子ｌの通過又は反射
は１回のみとしても本発明の方法は十分実現が可能であ
る。また、本発明の方法では基準尺として回折格子を用
いることが理想的ではあるが、角度の測定に対しては回
転角を検出するロータリーエンコーダを用いてもよく、
更には他の光学的機構、磁気的機構により検出される基
準尺を利用しても同様に測定が可能である。In some of the embodiments described above, the measurement head section 3 utilizes the interference of diffracted light by the diffraction grating l, and the diffracted light passes through or reflects the diffraction grating l twice, so that highly accurate measurement values can be obtained. However, the method of the present invention can be fully realized even if the light passes through the diffraction grating l only once or is reflected only once. Furthermore, although it is ideal to use a diffraction grating as a reference standard in the method of the present invention, a rotary encoder that detects the rotation angle may also be used to measure angles.
Furthermore, measurements can be made in the same way using standard standards detected by other optical or magnetic mechanisms.
また、実施例では使用する測定ヘッド部３を択一的に選
択するために、回折格子１の支持部材４にピンホール５
を設けるようにしたが、この検出は他の方式でもよいこ
とは勿論であり、ピンホール５に相当するようなマーク
を回折格子１に蒸着、塗布、添付等で耐着させることも
できる。In addition, in the embodiment, in order to selectively select the measuring head section 3 to be used, a pinhole 5 is provided in the support member 4 of the diffraction grating 1.
However, it goes without saying that this detection may be performed using other methods, and a mark corresponding to the pinhole 5 may be permanently attached to the diffraction grating 1 by vapor deposition, coating, attachment, or the like.
以−ヒ説明したように本発明に係る基準尺を用いた測長
方法は、高価な基準尺を全長にわたり配置することなく
、１個又は間欠的に配置された基準尺を用いて、高精度
の長さ測定を実現できる。As explained below, the length measurement method using the standard according to the present invention can achieve high accuracy by using one standard or intermittently placed standards without arranging expensive standards over the entire length. It is possible to measure the length of
第１図は回折格子の正面図、第２図は本発明の測定原理
の説明図、第３図は測定ヘッド部の構成図、第４図、第
５図は測定ヘッド部から得られる信号のタイムチャート
図、第６図は他の実施例の測定ヘッド部の構成図、第７
図は測定ヘッド部から得られるパルス波形図、第８図は
測定の変形例の説明図である。
符号ｌは回折格子、２は格子線、３は測定ヘッド部、４
は支持部材、５はピンホール、６は位置検知器、８ａ、
８ｂは検出器、１０ ａ、 ｌ Ｏｂｌ±偏向鏡、１
１はビームスプリッタ、１２ａ、１２ｂはダハプリズム
、１３ａ、１３ｂは位相差板である。
特許出願人 キャノン株式会社
１１２図
第３図
箇４図
纂５図
１６１１
１１７図Fig. 1 is a front view of the diffraction grating, Fig. 2 is an explanatory diagram of the measurement principle of the present invention, Fig. 3 is a configuration diagram of the measurement head, and Figs. 4 and 5 show the signal obtained from the measurement head. A time chart diagram, FIG. 6 is a configuration diagram of the measuring head section of another embodiment, and FIG.
The figure is a pulse waveform diagram obtained from the measurement head, and FIG. 8 is an explanatory diagram of a modification of measurement. Symbol l is the diffraction grating, 2 is the grating line, 3 is the measurement head, 4
is a support member, 5 is a pinhole, 6 is a position detector, 8a,
8b is a detector, 10a, l Obl± deflection mirror, 1
1 is a beam splitter, 12a and 12b are roof prisms, and 13a and 13b are phase difference plates. Patent applicant: Canon Co., Ltd. 112 Figure 3 Section 4 Figure 5 Collection 1611 Figure 117
Claims (1)
限長の基準尺を設置し、他方に前記基準尺との相対的位
置関係を前記基準量を単位として求める測定ヘッド部を
設け、前記２物体の相対的移動方向に前記基準尺の有効
長以内の間隔を置いて複数個の前記測定ヘッド部を配置
し、別に設けた位置検知器により適用すべき測定ヘッド
部を選択し、測定ヘッド部の基準量を単位とする出力を
計数して、２物体間の相対的移動量を測定することを特
徴とする基準尺を用いた測長方法。 ２、 前記基準尺を回折格子とした特許請求の範囲第１
項記載の基準尺を用いた測長方法。 ３、前記測定ヘッド部は回折光の干渉により移動量を測
定するようにした特許請求の範囲第２項記載の基準尺を
用いた測長方法。 ４、前記測定ヘッド部を等間隔に固定的に配置し、前記
間隔よりも長い有効長を有する１個の基準尺を移動する
ようにした特許請求の範囲第１項記載の基準尺を用いた
測長方法。 ５、複数個の基準尺を等間隔に固定的に配置し、２個の
測定ヘッド部を前記間隔よりも狭い間隔で保持し、これ
ら測定ヘッド部を移動するようにした特許請求の範囲第
１項記載の基準尺を用いた測長方法。[Claims] 1. A finite-length reference standard having a base of $1 is installed on one of two objects that move relatively, and the relative positional relationship with the reference standard is determined in units of the reference amount on the other. A measurement head to be sought is provided, a plurality of the measurement heads are arranged at intervals within the effective length of the standard in the direction of relative movement of the two objects, and a position sensor provided separately determines the measurement to be applied. 1. A length measuring method using a measuring standard, which comprises selecting a head, counting the output of the measuring head in units of a reference amount, and measuring the amount of relative movement between two objects. 2. Claim 1 in which the standard is a diffraction grating
Length measurement method using the standard listed in section. 3. A length measuring method using a measuring standard according to claim 2, wherein the measuring head measures the amount of movement by interference of diffracted light. 4. Using the measuring standard according to claim 1, in which the measuring heads are fixedly arranged at equal intervals, and one measuring standard having an effective length longer than the intervals is moved. Length measurement method. 5. A plurality of standard standards are fixedly arranged at equal intervals, two measuring heads are held at an interval narrower than the above-mentioned interval, and these measuring heads are movable. Length measurement method using the standard listed in section.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7480682A JPS58191906A (en) | 1982-05-04 | 1982-05-04 | Length measuring method using reference ruler |
| DE19833316144 DE3316144A1 (en) | 1982-05-04 | 1983-05-03 | Method and device for measuring the extent of a movement |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7480682A JPS58191906A (en) | 1982-05-04 | 1982-05-04 | Length measuring method using reference ruler |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS58191906A true JPS58191906A (en) | 1983-11-09 |
Family
ID=13557917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7480682A Pending JPS58191906A (en) | 1982-05-04 | 1982-05-04 | Length measuring method using reference ruler |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58191906A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01210803A (en) * | 1988-02-19 | 1989-08-24 | Kitamura Mach Co Ltd | Laser length measuring method |
| US4868385A (en) * | 1985-07-10 | 1989-09-19 | Canon Kabushiki Kaisha | Rotating state detection apparatus using a plurality of light beams |
| US4930895A (en) * | 1987-06-15 | 1990-06-05 | Canon Kabushiki Kaisha | Encoder for forming interference fringes by re-diffracted lights from an optical type scale and photoelectrically converting the interference fringes to thereby detect the displacement of the scale |
| US4967072A (en) * | 1984-09-05 | 1990-10-30 | Canon Kabushiki Kaisha | Interferometric rotating condition detection apparatus |
| US4998798A (en) * | 1988-05-10 | 1991-03-12 | Canon Kabushiki Kaisha | Encoder having long length measuring stroke |
| US5000572A (en) * | 1987-05-11 | 1991-03-19 | Canon Kabushiki Kaisha | Distance measuring system |
| US5036192A (en) * | 1986-01-14 | 1991-07-30 | Canon Kabushiki Kaisha | Rotary encoder using reflected light |
| US5101102A (en) * | 1986-02-28 | 1992-03-31 | Canon Kabushiki Kaisha | Rotary encoder having a plurality of beams emitted by a diffraction grating |
| US5122660A (en) * | 1987-05-11 | 1992-06-16 | Canon Kabushiki Kaisha | Distance measuring system utilizing an object with at least one inclined surface |
| KR101117241B1 (en) | 2004-04-22 | 2012-03-15 | 가부시키가이샤 마그네스케일 | Displacement detection apparatus |
-
1982
- 1982-05-04 JP JP7480682A patent/JPS58191906A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4967072A (en) * | 1984-09-05 | 1990-10-30 | Canon Kabushiki Kaisha | Interferometric rotating condition detection apparatus |
| US4868385A (en) * | 1985-07-10 | 1989-09-19 | Canon Kabushiki Kaisha | Rotating state detection apparatus using a plurality of light beams |
| US5036192A (en) * | 1986-01-14 | 1991-07-30 | Canon Kabushiki Kaisha | Rotary encoder using reflected light |
| US5101102A (en) * | 1986-02-28 | 1992-03-31 | Canon Kabushiki Kaisha | Rotary encoder having a plurality of beams emitted by a diffraction grating |
| US5000572A (en) * | 1987-05-11 | 1991-03-19 | Canon Kabushiki Kaisha | Distance measuring system |
| US5122660A (en) * | 1987-05-11 | 1992-06-16 | Canon Kabushiki Kaisha | Distance measuring system utilizing an object with at least one inclined surface |
| US4930895A (en) * | 1987-06-15 | 1990-06-05 | Canon Kabushiki Kaisha | Encoder for forming interference fringes by re-diffracted lights from an optical type scale and photoelectrically converting the interference fringes to thereby detect the displacement of the scale |
| JPH01210803A (en) * | 1988-02-19 | 1989-08-24 | Kitamura Mach Co Ltd | Laser length measuring method |
| JPH0585001B2 (en) * | 1988-02-19 | 1993-12-06 | Kitamura Machinery Co Ltd | |
| US4998798A (en) * | 1988-05-10 | 1991-03-12 | Canon Kabushiki Kaisha | Encoder having long length measuring stroke |
| KR101117241B1 (en) | 2004-04-22 | 2012-03-15 | 가부시키가이샤 마그네스케일 | Displacement detection apparatus |
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