JPH03255909A - Position measuring instrument - Google Patents
Position measuring instrumentInfo
- Publication number
- JPH03255909A JPH03255909A JP5612190A JP5612190A JPH03255909A JP H03255909 A JPH03255909 A JP H03255909A JP 5612190 A JP5612190 A JP 5612190A JP 5612190 A JP5612190 A JP 5612190A JP H03255909 A JPH03255909 A JP H03255909A
- Authority
- JP
- Japan
- Prior art keywords
- measured
- light
- light source
- point
- psd
- 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
- 238000005259 measurement Methods 0.000 claims abstract description 13
- 238000001514 detection method Methods 0.000 claims description 9
- 238000006073 displacement reaction Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
Landscapes
- Measurement Of Optical Distance (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は光源から被測定物上に投光した光の反射光を位
置検出素子（以下ＰＳＤと称する）上に結像させ、その
光点の位置によって被測定物の位置を測定する位置測定
装置に関する。Detailed Description of the Invention [Industrial Application Field] The present invention focuses the reflected light of the light projected onto the object to be measured from the light source onto a position detection element (hereinafter referred to as PSD), and The present invention relates to a position measuring device that measures the position of an object based on the position of the object.
一般に、被測定物の基準点に対する距離や変位を三角測
量法を用いて光学的に測定する位置測定装置は、例えば
第３図に示すように構成されている。すなわち、光源１
が発生する拡散光を投光レンズ２によって細く絞り、こ
の投光ビーム３を被測定物４の被測定面５上に照射する
。投光ビーム３を細く絞るのは測定誤差の要因となる光
源の拡散光を極力抑えるためである。Generally, a position measuring device that optically measures the distance or displacement of an object to a reference point using triangulation is configured as shown in FIG. 3, for example. That is, light source 1
The diffused light generated is narrowed down by a projection lens 2, and this projection beam 3 is irradiated onto a surface to be measured 5 of an object to be measured 4. The reason why the projected light beam 3 is narrowed is to suppress as much as possible the diffused light from the light source that causes measurement errors.
被測定面５上に照射された光は拡散反射し、この反射光
の一部は受光レンズ６によって集光され、受光部である
ＰＳＤ７上に結像して、その光点の位置により被測定物
４の位置を測定している。すなわち、被測定物４の被測
定面５がＡの位置にあれば、ＰＳＤ７上に結像された光
点はＸの位置にあり、被測定面５がＢの位置にあれば光
点はＹの位置にある。このように、ＰＳ、Ｄ７上の光点
の位置は被測定面５の位置に対応して変化するので、こ
の光点の位置から被測定面５までの距離を測定すること
ができる。The light irradiated onto the surface to be measured 5 is diffusely reflected, and a part of this reflected light is focused by the light receiving lens 6 and formed into an image on the PSD 7 which is the light receiving section, and the position of the light spot is reflected on the surface to be measured. The position of object 4 is being measured. That is, if the surface to be measured 5 of the object to be measured 4 is at position A, the light spot imaged on the PSD 7 is at position X, and if the surface to be measured 5 is at position B, the light spot is at position Y. It is located at In this way, since the position of the light spot on PS and D7 changes in accordance with the position of the surface to be measured 5, the distance from the position of this light spot to the surface to be measured 5 can be measured.
上記の構成によると被測定面５が鏡面の場合は、投光ビ
ーム３の反射光は拡散光とならず、ＰＳＤ７上にはほと
んど反射光が到達せず、測定が不可能となる。このため
従来は第４図に示すように、光源１から発する投光ビー
ム３の光軸と反射ビーム８の光軸とがそれぞれ被測定面
５とのなす角度が等しくθとなるように、予め投光ビー
ム３を傾むけていた。そして投光ビーム３を投光レンズ
２によって細く絞って、鏡面である被測定面５に照射し
、正反射方向にＰＳＤ７を配置して被測定物４の位！測
定を行なっていた。According to the above configuration, when the surface to be measured 5 is a mirror surface, the reflected light of the projected light beam 3 does not become diffused light, and almost no reflected light reaches the PSD 7, making measurement impossible. For this reason, conventionally, as shown in FIG. 4, the optical axis of the projected beam 3 emitted from the light source 1 and the optical axis of the reflected beam 8 are made in advance so that the angles θ with respect to the surface to be measured 5 are equal to each other. Projection beam 3 was tilted. Then, the projected light beam 3 is narrowed down by the projecting lens 2 and irradiated onto the surface to be measured 5, which is a mirror surface, and the PSD 7 is placed in the direction of specular reflection. was taking measurements.
しかしながら第４図に示す従来の位置測定装置によると
、被測定物４の被測定面５の位置がＡからＢへ平行移動
すると、投光ビーム３の反射ビーム８も平行移動して８
ａの位置に至る。このため反射光は受光レンズ６に到達
せず、ＰＳＤ７の受光光量が急激に低下するので、計測
範囲が広くとれないという問題があった。However, according to the conventional position measuring device shown in FIG.
Reach position a. For this reason, the reflected light does not reach the light receiving lens 6, and the amount of light received by the PSD 7 rapidly decreases, resulting in a problem that a wide measurement range cannot be obtained.
また第５図に示すように投光レンズ２により投光ビーム
３をコリメートして平行光線とした場合は、反射ビーム
８は受光レンズ６により焦点位置Ｆに集束される。従っ
て被測定面５がＡからＢ、Ｃへ移動しても、集束された
光点はすべて焦点Ｆの位置に一致して移動しないため、
被測定面５の変位を計測できない。ここで焦点Ｆから外
れた位置にＰＳＤ７を配置しても、受光スポットが大き
いためＰＳＤ７の受光面からはみ出す、この結果精度の
よい測定ができない欠点があった。Further, as shown in FIG. 5, when the projected light beam 3 is collimated by the projected lens 2 into parallel light beams, the reflected beam 8 is focused at the focal point F by the light receiving lens 6. Therefore, even if the surface to be measured 5 moves from A to B to C, all the focused light points do not move to coincide with the position of the focal point F.
The displacement of the surface to be measured 5 cannot be measured. Even if the PSD 7 is placed at a position away from the focal point F, the light receiving spot is large and extends beyond the light receiving surface of the PSD 7, resulting in a drawback that accurate measurement cannot be performed.
このため従来は第６図に示すように、投光レンズ２によ
り投光ビーム３を細く絞って被測定面５上に照射するこ
とにより、被測定物４の変位に対応して移動する光源１
の像をＰＳＤ７上に結像させることで、被測定物４の変
位を測定していた。For this reason, conventionally, as shown in FIG. 6, the light source 1 moves in response to the displacement of the object 4 by converging the projection beam 3 narrowly using the projection lens 2 and irradiating it onto the surface 5 to be measured.
By forming an image on the PSD 7, the displacement of the object to be measured 4 was measured.
しかしながら第６図に示す位置検出装置によると、被測
定面５がＡの位置にあるときは光源１の実像はＬａの位
置にあり、被測定面５がＢの位置にあるときは光源１の
実像は被測定面５上のＬｂの位置にあり、被測定面５が
Ｃの位置にあるときは光源１の虚像がＬｃの位置にある
。従がって反射ビーム８が受光レンズ６を通る位置が異
なり、第４図に示した場合と同様に、反射ビーム８によ
る光スポットの位置が大きく変化する。従って計測精度
を保証できる計測範囲が狭くなるという問題があった。However, according to the position detection device shown in FIG. 6, when the surface to be measured 5 is at position A, the real image of light source 1 is at position La, and when the surface to be measured 5 is at position B, the real image of light source 1 is at position La. The real image is at a position Lb on the surface to be measured 5, and when the surface to be measured 5 is at a position C, the virtual image of the light source 1 is at a position Lc. Therefore, the position where the reflected beam 8 passes through the light-receiving lens 6 is different, and the position of the light spot due to the reflected beam 8 changes greatly, similar to the case shown in FIG. Therefore, there is a problem that the measurement range in which measurement accuracy can be guaranteed becomes narrow.
本発明は上記の点に鑑みてなされたものであり、被測定
物の鏡面で形成された被測定面の位置を広い範囲で高精
度で計測することができる位置測定装置を提供すること
を目的とする。The present invention has been made in view of the above points, and an object of the present invention is to provide a position measuring device that can measure the position of a surface to be measured formed of a mirror surface of an object to be measured with high precision over a wide range. shall be.
本発明の位置測定装置は、被測定物の鏡面で形成された
被測定面上に光を投光する光源と、被測定面からの反射
光を結像させる受光レンズ、受光レンズにより結像され
た光点の位置を検出する位置検出素子とを具備し、光点
の位置検出素子上の位置によって、光源に対する被測定
物の位置を測定する位置測定装置であって、光源は被測
定面に拡散光が照射されるように光を発生することを特
徴とする。The position measuring device of the present invention includes a light source that projects light onto a surface to be measured formed of a mirror surface of an object to be measured, a light receiving lens that forms an image of reflected light from the surface to be measured, and a light receiving lens that forms an image. The position measuring device is equipped with a position detection element that detects the position of a light spot, and measures the position of an object to be measured with respect to a light source based on the position of the light spot on the position detection element. It is characterized by generating light such that diffused light is irradiated.
上記構成の位置測定装置においては、光源から出射され
る拡散光は、被測定物がいかなる位置に変位しても、鏡
面に写る虚像と受光レンズの中心とを結ぶ線が被測定面
と交わる交点上において、受光レンズの中心に向って正
反射する成分が必ず存在する。しかも被測定物の変位に
よる位置検出素子（Ｐ Ｓ Ｄ）の受光光量の変動も少
ないので、光源に対する被測定物の位置をＰＳＤにより
広範囲で高精度に計測できる。In the position measuring device with the above configuration, the diffused light emitted from the light source is transmitted to the intersection point where the line connecting the virtual image reflected on the mirror surface and the center of the light-receiving lens intersects the surface to be measured, no matter what position the object to be measured is displaced. Above, there is always a component that is specularly reflected toward the center of the light-receiving lens. Moreover, since there is little variation in the amount of light received by the position detection element (PSD) due to displacement of the object to be measured, the position of the object to be measured with respect to the light source can be measured over a wide range with high precision by the PSD.
以下、本発明の位置測定装置の一実施例を図面を参照し
て説明する。Hereinafter, one embodiment of the position measuring device of the present invention will be described with reference to the drawings.
第１図に本発明の一実施例を示す。なお、第４図に示す
従来の場合と対応する部分には同一符号を付けてあり、
その説明は適宜省略する。FIG. 1 shows an embodiment of the present invention. Note that parts corresponding to those in the conventional case shown in FIG. 4 are given the same reference numerals.
The explanation will be omitted as appropriate.
位置測定装！１１はＬＥＤや白熱電球などの拡散光源１
２、受光レンズ６及びＰＳＤ７とから構成されており、
拡散光源１２から発する拡散光の一部が被測定物４の被
測定面５によって正反射し、受光レンズ６を通ってＰＳ
Ｄ７上に結像するようになっている。Position measuring device! 11 is a diffused light source 1 such as an LED or an incandescent light bulb
2. It is composed of a light receiving lens 6 and a PSD 7,
A part of the diffused light emitted from the diffused light source 12 is specularly reflected by the measured surface 5 of the measured object 4, passes through the light receiving lens 6, and is transmitted to the PS.
The image is formed on D7.
次に本実施例の作用を説明する。被測定物４の鏡面で形
成された被測定面５がＡの位置にあるときに、Ｌの位置
にある拡散光源１２からの距離をｄａとする。このとき
被測定面５に対し光源１２と反対の方向に同じ距離ｄａ
の位置に光源１２の虚像Ｉａが形成される。この虚像Ｉ
ａと受光レンズ６の中心Ｏとを結ぶ直線が、被測定面５
及びＰＳＤ７の測定面と交わる点をそれぞれＰａ及び又
とし、光源１２から被測定面５に下ろした垂線の被測定
面５との交点をＱａとする。Next, the operation of this embodiment will be explained. When the surface to be measured 5 formed of a mirror surface of the object to be measured 4 is at the position A, the distance from the diffused light source 12 at the position L is defined as da. At this time, the same distance da in the direction opposite to the light source 12 with respect to the surface to be measured 5
A virtual image Ia of the light source 12 is formed at the position. This virtual image I
The straight line connecting a and the center O of the light receiving lens 6 is the surface to be measured 5
The points of intersection with the measurement surfaces of the PSD 7 and PSD 7 are respectively denoted by Pa and Mata, and the intersection of the perpendicular line drawn from the light source 12 to the surface to be measured 5 with the surface to be measured 5 is denoted by Qa.
また被測定面５がＢの位置にあるときの光源１２から被
測定面５までの距離をｄｂとし、上記各点Ｉａ、Ｐａ、
Ｘ及びＱａに対応する点をそれぞれＩｂ、Ｐｂ、Ｙ及び
Ｑｂとする０点し、Ｉａ、Ｐａを結ぶ直線で形成される
三角形は、被測定面５によって合同な２つの三角形に分
割される。従って。Further, the distance from the light source 12 to the surface to be measured 5 when the surface to be measured 5 is at position B is db, and each of the above points Ia, Pa,
A triangle formed by a straight line connecting Ia and Pa with the points corresponding to X and Qa being Ib, Pb, Y, and Qb, respectively, is divided into two congruent triangles by the surface to be measured 5. Therefore.
１ＬＰａＱａ＝ｌＩ ａＰａＱａ となる。1LPaQa=lI aPaQa becomes.
同様に、
ｌ Ｘ Ｐ ａ Ａ ＝ ｌ Ｉ ａ Ｐ ａ Ｑ
ａとなる。Similarly, l X P a A = l I a P a Q
It becomes a.
ここでＡとは被測定面上の点Ｑａから点Ｐａに向う延長
線上の任意の点とする。Here, A is any point on the extended line from point Qa to point Pa on the surface to be measured.
従って拡散光源１２から点Ｐａに向う投光ビーム３ａは
１点Ｐａで正反射して点Ｘに入射する。Therefore, the projected light beam 3a directed from the diffused light source 12 toward the point Pa is specularly reflected at one point Pa and enters the point X.
同様に拡散光源１２から点ｐｂに向う投光ビーム３ｂは
点ｐｂで正反射して点Ｙに入射する。Similarly, the projected light beam 3b directed toward point pb from the diffused light source 12 is specularly reflected at point pb and enters point Y.
従ってＰＳＤ７上で点Ｘ、Ｙの位置を測定することによ
り、被測定物４の移動した位置を測定することができる
。Therefore, by measuring the positions of points X and Y on the PSD 7, the position to which the object to be measured 4 has moved can be measured.
本実施例によれば、被測定物４がいかなる位置に変位し
ても、拡散光源１２から射出し、被測定面５で正反射し
た光が受光レンズ６の中心を通ってＰＳＤ７に到達する
ので、精度よく被測定物４の位置を測定することができ
る。According to this embodiment, no matter what position the object to be measured 4 is displaced, the light emitted from the diffused light source 12 and specularly reflected by the surface to be measured 5 passes through the center of the light receiving lens 6 and reaches the PSD 7. , the position of the object to be measured 4 can be measured with high accuracy.
また、光源としてレンズ系を具備しない拡散光源１２を
そのまま使用できるため、光学系を簡素化することがで
き光源の選択幅も広くすることができる。Furthermore, since the diffused light source 12 without a lens system can be used as a light source, the optical system can be simplified and the range of light sources available can be widened.
第２図に本発明の他の実施例を示す、なお第１図に示す
実施例の場合と対応する部分には同一符号を付してあり
、その説明は適宜省略する。FIG. 2 shows another embodiment of the present invention. Parts corresponding to those in the embodiment shown in FIG. 1 are denoted by the same reference numerals, and the explanation thereof will be omitted as appropriate.
本実施例は、拡散光源１２と被測定面５との間に投光レ
ンズ２１を設けたものであり、他の部分の構成は上記実
施例と同様である。In this embodiment, a light projecting lens 21 is provided between the diffused light source 12 and the surface to be measured 5, and the configuration of other parts is the same as that of the above embodiment.
本実施例によれば、拡散光源１２の被測定面５側から見
た投光レンズ２１による虚像Ｌａが、被測定面５から光
源１２より遠ざかるので、拡散光源１２は被測定面５の
狭い所定の範囲のみ拡散照明する。従って計測範囲外に
拡散する光を計測範囲内に集めることができ、計測精度
が向上する。According to this embodiment, the virtual image La produced by the projection lens 21 viewed from the side of the surface to be measured 5 of the diffused light source 12 is moved away from the surface to be measured 5 from the light source 12, so that the diffused light source 12 is Diffuse illumination only in the area. Therefore, light that is diffused outside the measurement range can be collected within the measurement range, improving measurement accuracy.
以上説明したように、本発明の位置測定装置によれば、
光源として拡散光源を用いたので、被測定物の位置を広
い範囲で高精度に計測することができる。As explained above, according to the position measuring device of the present invention,
Since a diffused light source is used as the light source, the position of the object to be measured can be measured over a wide range with high precision.
第１図は本発明の位置測定装置の一実施例の構成及び作
用を説明する線図、第２図は同じく他の実施例を説明す
る線図、第３図乃至第６図はそれぞれ従来の位置測定装
置の構成及び作用を説明する線図である。
１・・・光源、４・・・被測定物、５・・・被測定面、
６・・・受光レンズ、７・・・位置検出素子（ＰＳＤ）
、１２・・・拡散光源、２１・・・投光レンズ（レンズ
系）。FIG. 1 is a diagram illustrating the configuration and operation of one embodiment of the position measuring device of the present invention, FIG. 2 is a diagram illustrating another embodiment, and FIGS. FIG. 2 is a diagram illustrating the configuration and operation of a position measuring device. 1... Light source, 4... Measured object, 5... Measured surface,
6... Light receiving lens, 7... Position detection element (PSD)
, 12... Diffuse light source, 21... Light projecting lens (lens system).
Claims (1)
光源と、前記被測定面からの反射光を結像させる受光レ
ンズと、前記受光レンズにより結像された光点の位置を
検出する位置検出素子とを具備し、前記光点の前記位置
検出素子上の位置によって、前記光源に対する前記被測
定物の位置を測定する位置測定装置であって、前記光源
は前記被測定面に拡散光が照射されるように光を発生す
ることを特徴とする位置測定装置。A light source that projects light onto a surface to be measured formed of a mirror surface of an object to be measured, a light receiving lens that forms an image of the light reflected from the surface to be measured, and a position of a light spot imaged by the light receiving lens. a position detection element that detects a position detection element, the position measurement device measures the position of the object to be measured with respect to the light source based on the position of the light spot on the position detection element, wherein the light source is located on the surface to be measured. A position measuring device characterized in that it generates light such that diffused light is irradiated on the area.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5612190A JPH03255909A (en) | 1990-03-06 | 1990-03-06 | Position measuring instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5612190A JPH03255909A (en) | 1990-03-06 | 1990-03-06 | Position measuring instrument |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03255909A true JPH03255909A (en) | 1991-11-14 |
Family
ID=13018240
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5612190A Pending JPH03255909A (en) | 1990-03-06 | 1990-03-06 | Position measuring instrument |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03255909A (en) |
-
1990
- 1990-03-06 JP JP5612190A patent/JPH03255909A/en active Pending
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