JPH01185410A - Optical length measuring method - Google Patents

Optical length measuring method

Info

Publication number
JPH01185410A
JPH01185410A JP1154688A JP1154688A JPH01185410A JP H01185410 A JPH01185410 A JP H01185410A JP 1154688 A JP1154688 A JP 1154688A JP 1154688 A JP1154688 A JP 1154688A JP H01185410 A JPH01185410 A JP H01185410A
Authority
JP
Japan
Prior art keywords
measured
spot
length
long axis
distance
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.)
Granted
Application number
JP1154688A
Other languages
Japanese (ja)
Other versions
JP2717250B2 (en
Inventor
Nobuyuki Suzuki
信幸 鈴木
Yasuo Ishiguro
石黒 恭生
Yoshito Kato
加藤 由人
Koji Morishita
森下 耕次
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Omron Corp
Toyota Motor Corp
Original Assignee
Toyota Motor Corp
Omron Tateisi Electronics Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Toyota Motor Corp, Omron Tateisi Electronics Co filed Critical Toyota Motor Corp
Priority to JP63011546A priority Critical patent/JP2717250B2/en
Publication of JPH01185410A publication Critical patent/JPH01185410A/en
Application granted granted Critical
Publication of JP2717250B2 publication Critical patent/JP2717250B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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  • Length Measuring Devices By Optical Means (AREA)
  • Measurement Of Optical Distance (AREA)

Abstract

PURPOSE:To reduce the measuring error of a spot position, by allowing the long axis of the oval spot striking on an object to be measured to coincide with the direction vertical to the surface containing the respective optical axes of both condensing lenses and setting the length of said long axis to 1.5-3.0mm. CONSTITUTION:The spot SP of laser beam 12 is formed on an object W to be measured and the long axis of said spot SP is allowed to coincide with the direction vertical to the surface S containing the respective optical axes Z1, Z2 of condensing lenses 13, 16. Because of this, the short axis direction of the spot SP becomes the image moving direction on a beam receiving position detector 15 generated by the change of the distance up to the object W to be measured and the center position detection error of the spot SP generated at the boundary part of the hue on the object W to be measured is only generated within the length range of the short axis of the spot SP. Therefore, the center position detection error of the object W to be measured can be reduced in such a state that the noise caused by the surface roughness of the object W to be measured is held to the same degree. Further, by setting the length of the long axis of the spot SP to 1.5-3.0mm, the noise generated by the surface roughness of the object W to be measured can be reduced.

Description

【発明の詳細な説明】 え脈Ω旦句 [産業上の利用分野] 本発明は、光ビームを被測定物体に段剥し、その乱反射
光から被測定物体までの距離または被測定物体の変位を
測定する光学式測長方法に関する。
[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method of emitting a light beam onto an object to be measured and calculating the distance to the object or the displacement of the object from the diffusely reflected light. This invention relates to an optical length measurement method.

[従来の技術] 従来、こうした光学式測長方法を採用した計測器として
、第5図に示すようなものがあった。同図に示すように
、投光器1から投光される光ビーム2を、集光レンズ3
を介して被測定物体5にスポットを結ぶように当てて、
そしてその乱反射光を、集光レンズ6を介して集光して
、所定の位置に配置された半導体装置検出器7に結像さ
せる。
[Prior Art] Conventionally, there has been a measuring instrument as shown in FIG. 5 that employs such an optical length measuring method. As shown in the figure, a light beam 2 projected from a light projector 1 is directed through a condensing lens 3.
Apply the spot to the object to be measured 5 through the
The diffusely reflected light is then condensed through a condensing lens 6 to form an image on a semiconductor device detector 7 disposed at a predetermined position.

そうすると、半導体装置検出器7はその結像点の位置を
検出するものであるから、その結像点の位置から、三角
測量法の原理に基づいて被測定物体5までの距離を測定
することができる。
Then, since the semiconductor device detector 7 detects the position of the imaging point, the distance to the object to be measured 5 can be measured from the position of the imaging point based on the principle of triangulation. can.

ところで、前記投光器1としては、発光ダイオードや半
導体レーザ等が用いられるが、発光ダイオードを用いた
ときの被測定物体上のスポットは円形をしており、また
半導体レーザを用いたときの被測定物体上のスポットは
楕円形をしている。
By the way, as the projector 1, a light emitting diode, a semiconductor laser, etc. are used, but when a light emitting diode is used, the spot on the object to be measured is circular, and when a semiconductor laser is used, the spot on the object to be measured is circular. The upper spot has an oval shape.

[発明が解決しようとする課題] しかしながら、前記従来の光学式測長方法では、例えば
、被測定物体上の白黒の境界部に光ビームのスポットを
当てようとすると、スポットの一部分(被測定物体の白
色部分を投射する部分)だけが強く反射し、半導体装置
検出器7は、スポットのその一部分だけを検出してしま
うことがあった。
[Problems to be Solved by the Invention] However, in the conventional optical length measurement method, when trying to shine a light beam spot on the boundary between black and white on an object to be measured, a part of the spot (the object to be measured There have been cases where only the part (projecting the white part of the spot) is strongly reflected, and the semiconductor device detector 7 detects only that part of the spot.

このために、半導体検出器7の検出結果は、スポットの
中心位置と偏差を持った位置を該スポットの中心として
検出したものになり、測定結果としての被測定物体5と
の距離が、誤差を含んだものになる問題が生じた。
For this reason, the detection result of the semiconductor detector 7 is a position that has a deviation from the center position of the spot. A problem arose that included the following.

なお、この誤差を小さなものにするには、被測定物体上
のスポットの面積を小さくすれば良いが、スポットの面
積を小さくすると、被測定物体5の表面粗さに起因して
生じる半導体検出器7の検出信号のノイズが大きくなる
問題が生じ、正確な測定結果を得ることができなかった
Note that this error can be reduced by reducing the area of the spot on the object to be measured. A problem arose in that the noise in the detection signal No. 7 increased, making it impossible to obtain accurate measurement results.

本発明は、前記問題点に鑑みてなされたもので、被測定
物体の表面粗さに起因して発生するノイズを低く抑えた
ままで、被測定物体上の白黒等の色彩の境界部分で発生
するスポット位置の測定誤差を小さくした光学式測長方
法を提供することを目的とする。
The present invention has been made in view of the above-mentioned problems, and it suppresses the noise generated due to the surface roughness of the object to be measured while suppressing the noise that occurs at the boundary between colors such as black and white on the object to be measured. It is an object of the present invention to provide an optical length measurement method that reduces measurement errors in spot positions.

え咀夏復戒 [課題を解決するための手段] かかる目的を達成するために、前記問題点を解決するた
めの手段として、本発明は以下に示す構成を取った。即
ち、本発明の光学式測長方法は、断面が楕円形の光ビー
ムの投光器から投光される光ビームを集光レンズを介し
て被測定物体上にスポットを結ぶように当てて、その乱
反射光を他の集光レンズを介して集光し所定の位置に配
置された受光位置検出器に当てて、その受光位置検出器
の検出結果から前記被測定物体までの距離または前記被
測定物体の変位を測定する光学式測長方法において、 前記被測定物体上に当たる楕円形のスポットの長軸を、
前記両集光レンズの夫々の光軸を含む面に対して垂直な
方向に一致させて、長さ1.5mm〜3.0mmにした
ことを要旨としている。
[Means for Solving the Problems] In order to achieve the above object, the present invention adopts the configuration shown below as a means for solving the above problems. That is, in the optical length measurement method of the present invention, a light beam projected from a light beam projector having an elliptical cross section is directed onto an object to be measured through a condensing lens so as to form a spot, and the diffused reflection is detected. The light is focused through another condensing lens and applied to a light-receiving position detector placed at a predetermined position, and the distance to the object to be measured or the distance to the object to be measured is determined from the detection result of the light-receiving position detector. In the optical length measurement method for measuring displacement, the long axis of the elliptical spot on the object to be measured is
The gist is that the lengths of the two condensing lenses are 1.5 mm to 3.0 mm and are aligned in a direction perpendicular to a plane including the respective optical axes of both the condenser lenses.

[作用] 以上のように構成された本発明の光学式測長方法によれ
ば、被測定物体上に楕円形の光ビームのスポットが形成
され、しかも、その楕円形のスポットの長軸を、前記投
光側の集光レンズおよび受光側の集光レンズの夫々の光
軸を含む面に対して垂直な方向に一致させている。この
ため、前記楕円形のスポットの短軸方向が、被測定物体
までの距離変化により生じる受光位置検出器上での像移
動の方向となり、被測定物体上の白黒等の色彩の境界部
分で発生するスポットの中心位置検出誤差は、その短軸
の長さの範囲でしか起こらない。したがって、発光ダイ
オード等の円形スポットと比較して、そのスポットの面
積を同じ大きさのまま、■口ち、被測定物体の表面粗さ
に起因して発生するノイズを同じ程度のままで、前記ス
ポットの中心位置検出誤差を小さくすることができ、ま
た、当然、半導体レーザ等の楕円形ビームであって投射
するスポットの方向を定めていないものと比較して、前
記スポットの中心位置検出誤差を小さくすることができ
る。さらに、被測定物体上の楕円形のスポットの長軸を
長さ1.5mm〜3.0mmにすることにより、第4図
に示すように、被測定物体の凹凸の段差にスポットが位
置したときに発生するダレを許容範囲に抑えた状態で、
被測定物体の表面粗さに起因して発生するノイズを小さ
くすることができる。
[Operation] According to the optical length measurement method of the present invention configured as described above, an elliptical light beam spot is formed on the object to be measured, and the long axis of the elliptical spot is The condensing lens on the light emitting side and the condensing lens on the light receiving side are aligned in a direction perpendicular to a plane including their respective optical axes. Therefore, the short axis direction of the elliptical spot becomes the direction of image movement on the light receiving position detector caused by a change in distance to the object to be measured, and this occurs at the boundary between colors such as black and white on the object to be measured. The error in detecting the center position of the spot occurs only within the length of its short axis. Therefore, compared to a circular spot such as a light emitting diode, the area of the spot remains the same, and the noise generated due to the surface roughness of the object to be measured remains the same. It is possible to reduce the error in detecting the center position of the spot, and of course the error in detecting the center position of the spot can be reduced compared to an elliptical beam such as a semiconductor laser whose direction of the projected spot is not determined. Can be made smaller. Furthermore, by setting the long axis of the elliptical spot on the object to be measured to a length of 1.5 mm to 3.0 mm, as shown in Fig. 4, when the spot is located on a step in the unevenness of the object to be measured, With the sag that occurs within the allowable range,
Noise generated due to surface roughness of the object to be measured can be reduced.

[実施例コ 以下、本発明の一実施例の光学式測長方法を採用した計
測器について詳細に説明する。
[Embodiment 1] A measuring instrument employing an optical length measuring method according to an embodiment of the present invention will be described in detail below.

第1図は、その計測器の概略を示す斜視図である。同図
に示すように、その計測器は、被測定物体Wに断面楕円
形のレーザ光を照射する半導体レーザ11と、半導体レ
ーザ11と被測定物体Wとの間に設けられて、半導体レ
ーザ11からの光ビーム12を集光して被測定物体Wに
スボッ)SPを結ぶように当てる集光レンズ13と、被
測定物体Wに対して半導体レーザ11側の所定の位置に
配置され、結像点(スボッ)SP)の位置を検出する半
導体装置検出器(PSD)15と、被測定物体WとPS
D15との間に設けられて、被測定物体Wからの乱反射
光をPSD15に集めて当てる集光レンズ16とから構
成されるもので、しかも、半導体レーザ11をその中心
軸を中心として回転させて位置決めすることにより、被
測定物体W上に結ばれる楕円形のスポラ)SPの長軸が
両集光レンズ13.16の夫々の光軸Z1.Z2を舎む
面Sに対して垂直な方向Kに一致するようになされてお
り、また、半導体レーザ11と集光しンズ13との距離
Qを調整して、測定距離りのところに結ばれるスポラ)
SPの長軸が長さ1.5n1m〜3.0mmとなるよう
に、測定距離りの許容範囲が定められている。
FIG. 1 is a perspective view schematically showing the measuring instrument. As shown in the figure, the measuring instrument includes a semiconductor laser 11 that irradiates a laser beam having an elliptical cross section onto an object W to be measured, and a semiconductor laser 11 that is provided between the semiconductor laser 11 and the object W to be measured. A condenser lens 13 is arranged at a predetermined position on the side of the semiconductor laser 11 with respect to the object W to be measured, and is arranged at a predetermined position on the side of the semiconductor laser 11 with respect to the object W to be measured to form an image. A semiconductor device detector (PSD) 15 that detects the position of a point (SP), and an object to be measured W and PS
D15, the condenser lens 16 is provided between the PSD 15 and the PSD 15 to collect the diffusely reflected light from the object W to be measured onto the PSD 15, and the semiconductor laser 11 is rotated about its central axis. By positioning, the long axis of the elliptical spora) SP connected on the object W to be measured is aligned with the optical axis Z1. Z2 is aligned with the direction K perpendicular to the housing surface S, and the distance Q between the semiconductor laser 11 and the condensing lens 13 is adjusted so that the laser beam is connected at the measurement distance. spora)
The allowable range of the measurement distance is determined so that the length of the long axis of SP is 1.5n1m to 3.0mm.

なお、半導体レーザ11から投光される光ビーム12の
断面は既述したように楕円形をしているが、その楕円形
の短軸の長さは、その長軸の30%から60%(本実施
例の場合には40%)である。
The cross section of the light beam 12 emitted from the semiconductor laser 11 is elliptical as described above, and the length of the short axis of the ellipse is 30% to 60% ( In the case of this example, it is 40%).

以上のように構成された計測器によれば、PS015の
検出した位置信号から、三角測量法の原理に基づいて、
被測定物体Wまでの距離または被測定物体Wの交情を測
定することができる。
According to the measuring instrument configured as above, based on the principle of triangulation method, from the position signal detected by PS015,
The distance to the object W to be measured or the intimacy of the object W to be measured can be measured.

なお、被測定物体Wに結ばれる楕円形のスポットSPの
長軸が長さ1.5mm 〜3.0mmとなるように、測
定距離りの許容範囲が定められているのはどうゆう理由
によるものかを、第2図ないし第4図のグラフを用いて
以下説明する。  ゛第2図(a)は、光ビーム12の
焦点距離を100mmとした場合に、被測定物体Wまで
の距離りと、被測定物体W上に形成される楕円形のスポ
ラ)SPの長軸長および短軸長との関係を示すグラフで
あり、第2図(b)は、第2図(a)の条件で各測定距
離りが80mm、100mm、120mmのときに、P
SD15で検出される段差特性データを示すグラフであ
る。また、第3図(a)は、光ビーム12の焦点距離を
200mmとした場合に、被測定物体Wまでの距離りと
、被測定物体W上に形成される楕円形のスポラ)SPの
長軸長および短軸長との関係を示すグラフであり、第3
図(b)は、第3図(a)の条件で各測定距離りが80
mm、100mm、120mmのときに、PSD15で
検出される段差特性データを示すグラフである。なお、
これら段差特性データは、被測定物体Wの表面を矩形の
凹凸を有するようにして、被測定物体Wに対して平行に
本実施例の計測器を移動させることにより、実験的に得
たものである。第2図(a)および第2図(b)から分
かるように、被測定物体W上に形成される楕円の長軸長
および短軸長が短くなる(即ち、楕円の面積が小さくな
る)と、PSD15で検出される段差特性データは、ノ
イズを多く含んだものとなり(被測定物体Wまでの距離
りが100mmのとき、最もノイズが多い。)、また、
第3図(a)および第3図(b)から分かるように、被
測定物体W上に形成される楕円の長軸長および短軸長が
長くなると、PSD15で検出される段差特性データは
、段差部分の立ち上がりまたは立ち下がり部分の誤差を
示すダレが大きくなったものになっている。「ダレ」を
さらに詳しく説明するなら、被測定物体Wの表面が垂直
な段差を持っている場合に、この段差を、垂直な立ち上
がり(または立ち下がり)としてではなく、傾きを持っ
た立ち上がり(立ち下がり)として検出することがある
が、この立ち上がりまたは立ち下がりに要する移動距離
を、「ダレ」と言っている。そして、第4図は、既述し
たノイズおよびダレの大きさと楕円形のスポラ)SPの
長軸長との関係を示すグラフであり、この図から、ダレ
を許容範囲(3mm以下)に抑えた状態で、被測定物体
の表面粗さに起因して発生するノイズを小さくするには
、楕円形のスポットSPの長軸を長さ1.5mm〜3.
0mmとすることが最も良いことが分かる。
Furthermore, for some reason, the tolerance range for the measurement distance is set so that the long axis of the elliptical spot SP connected to the object W to be measured is 1.5 mm to 3.0 mm in length. This will be explained below using the graphs in FIGS. 2 to 4.゛Figure 2 (a) shows the distance to the object W to be measured and the long axis of the elliptical spora) SP formed on the object W to be measured when the focal length of the light beam 12 is 100 mm. FIG. 2(b) is a graph showing the relationship between the long and short axis lengths, and FIG. 2(b) shows the P
It is a graph showing step difference characteristic data detected by SD15. Furthermore, when the focal length of the light beam 12 is 200 mm, FIG. 3(a) shows the distance to the object W to be measured and the length of the elliptical spora) SP formed on the object W to be measured. It is a graph showing the relationship between the axis length and the short axis length, and the third
Figure (b) shows that each measured distance is 80% under the conditions of Figure 3 (a).
It is a graph showing step characteristic data detected by the PSD 15 when the height is mm, 100 mm, and 120 mm. In addition,
These level difference characteristic data were obtained experimentally by moving the measuring instrument of this example parallel to the object W to be measured, with the surface of the object W to be measured having rectangular irregularities. be. As can be seen from FIGS. 2(a) and 2(b), when the major axis length and minor axis length of the ellipse formed on the object W to be measured become shorter (that is, the area of the ellipse becomes smaller), , the level difference characteristic data detected by the PSD 15 contains a lot of noise (noisiest when the distance to the object W to be measured is 100 mm), and
As can be seen from FIGS. 3(a) and 3(b), as the major axis length and minor axis length of the ellipse formed on the object W to be measured become longer, the step characteristic data detected by the PSD 15 becomes The sag, which indicates an error in the rising or falling portion of the stepped portion, is increased. To explain "sag" in more detail, when the surface of the object W to be measured has a vertical step, this step is not treated as a vertical rise (or fall), but as a sloped rise (or fall). The moving distance required for this rise or fall is called "sag". Fig. 4 is a graph showing the relationship between the size of the noise and sag mentioned above and the long axis length of the elliptical spora In order to reduce the noise generated due to the surface roughness of the object to be measured, the long axis of the elliptical spot SP should be set to a length of 1.5 mm to 3 mm.
It can be seen that it is best to set it to 0 mm.

゛以上のように構成された本実施例の光学式測長方法に
よれば、被測定物体W上に形成される楕円形のスポット
SPの長軸が、集光レンズ13および集光レンズ16の
夫々の光軸Z1.Z2を含む面Sに対して垂直な方向K
に一致するように構成されているために、そのスポラ)
SPの短軸方向が、被測定物体Wまでの距離変化により
生じるP5D15・上での像移動の方向となり、複測定
物体W上の白黒等の色彩の境界部分で発生するスポッ)
SPの中心位置検出誤差は、その短軸の長さの5籟囲で
しか起こらず、PSD15におけるスポッ)SPの位置
を検出する誤差を低減することができる。また、被測定
物体W上の楕円形のスポットSPの長軸を長さ1.5m
m 〜3.0mmにすることにより、被測定物体Wの凹
凸の段差にスポットSPが位置したときに発生するダレ
を許容範囲に抑えた状態で、被測定物体Wの表面粗さに
起因して発生するノイズを小さくすることができる。
According to the optical length measurement method of this embodiment configured as described above, the long axis of the elliptical spot SP formed on the object W to be measured is aligned with the condenser lens 13 and the condenser lens 16. Each optical axis Z1. Direction K perpendicular to plane S including Z2
(because its spora is configured to match)
The short axis direction of SP is the direction of image movement on P5D15 caused by a change in distance to the object W to be measured, and spots that occur at the boundary between colors such as black and white on the multi-measurement object W)
The error in detecting the center position of the SP occurs only within 5 squares of the length of its short axis, and the error in detecting the position of the SP in the PSD 15 can be reduced. In addition, the long axis of the oval spot SP on the object W to be measured is 1.5 m long.
By setting m to 3.0 mm, the sag that occurs when the spot SP is positioned on the uneven step of the object W to be measured is suppressed to an allowable range, and the sag caused by the surface roughness of the object W to be measured is suppressed. Generated noise can be reduced.

したがって、本計測器は、高精度な測定結果を得ること
ができる。
Therefore, this measuring instrument can obtain highly accurate measurement results.

ざらに、既述したようここ、スポットSPの短軸方向が
、被測定物体Wまでの距離変化により生じるPSD15
上での像移動の方向となっているために、従来の円形ス
ポット等ではPSD15の受光位置からはみ出す像もP
SD15で検出することができ、測定距離りの許容範囲
を広く取ることができる。
Roughly speaking, as already mentioned, the short axis direction of the spot SP is PSD15 caused by a change in the distance to the object W to be measured.
Due to the direction of image movement at the top, with conventional circular spots, etc., the image that extends beyond the light receiving position of the PSD 15 may also be
It can be detected with SD15, and the permissible range of measurement distance can be widened.

以上、本発明の一実施例を詳述してきたが、本発明は、
前記実施例に同等限定されるものではなく、例えは、投
光器としての半導体レーザ11に替えて、発光ダイオー
ドの投射口に楕円形の孔の開いた遮弊板を設けたものを
用いた構成等、本発明の要旨を逸脱しない範囲において
種々なる態様にて実施することができるのは勿論のこと
である。
Although one embodiment of the present invention has been described in detail above, the present invention includes
The present invention is not limited to the above-mentioned embodiments; for example, instead of the semiconductor laser 11 as a light projector, a structure in which a shielding plate with an oval hole is provided at the projection port of the light emitting diode may be used. It goes without saying that the invention can be implemented in various ways without departing from the gist of the invention.

え肌皇効】 以上詳述したように本発明の光学式測長方法膣−によれ
ば、被測定物体の表面粗さに起因して発生するノイズを
低く抑えたままで、被測定物体上の白黒等の色彩の境界
部分で発生するスポーツト位置の測定誤差を小さくし、
被測定物体までの距離または前記被測定物体の変位を高
精度で測定することができる。
As described in detail above, according to the optical length measurement method of the present invention, the noise generated due to the surface roughness of the object to be measured can be kept low, while Reduces sports position measurement errors that occur at color boundaries such as black and white,
The distance to the object to be measured or the displacement of the object to be measured can be measured with high precision.

また、従来の円形スポット等では受光位置検出器の受光
位置からはみ出す像もその受光位置検出器で検出するこ
とができ、測定可能な距離の許容範囲を広く取ることが
できる。
Further, in the case of a conventional circular spot or the like, an image extending beyond the light receiving position of the light receiving position detector can be detected by the light receiving position detector, and the allowable range of measurable distance can be widened.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明の一実施例を採用した計測器の概略を示
す斜視図、第2図(a)は光ビームの焦点距離を100
mmとした場合に被測定物体Wまでの距離りと、楕円形
のスポットの長軸長および短軸長との関係を示すグラフ
、第2図(b)は第2図(a)の条件で夫゛々の測定距
離における段差特性データを示すグラフ、第3図(a)
は光ビームの焦点距離を200mmとした場合に被測定
物体Wまでの距離りと、楕円形のスポットの長軸長およ
び短軸長との関係を示すグラフ、第3図(b)は第3図
(a)の条件で夫々の測定距離における段差特性データ
を示すグラフ、第4図はノイズおよびダレの大きさと楕
円形のスポットの長軸長との関係を示すグラフ、第5図
は従来技術の説明図である。 W・・・被測定物体 11・・・半導体レーザ 13・・・集光レンズ 15・・・半導体装置検出器(P S D)16・・・
集光レンズ SP・・・楕円形のスポット
FIG. 1 is a perspective view schematically showing a measuring instrument employing an embodiment of the present invention, and FIG. 2(a) shows a focal length of a light beam of 100
Figure 2 (b) is a graph showing the relationship between the distance to the object W to be measured and the major axis length and minor axis length of the elliptical spot when mm is set, under the conditions of Figure 2 (a). Graph showing step difference characteristic data at each measurement distance, Figure 3 (a)
is a graph showing the relationship between the distance to the object to be measured W and the major axis length and minor axis length of the elliptical spot when the focal length of the light beam is 200 mm. A graph showing the level difference characteristic data at each measurement distance under the conditions shown in Fig. (a). Fig. 4 is a graph showing the relationship between the size of noise and sag and the major axis length of an elliptical spot. Fig. 5 is a graph showing the conventional technology. FIG. W...Object to be measured 11...Semiconductor laser 13...Condensing lens 15...Semiconductor device detector (PSD) 16...
Condensing lens SP...elliptical spot

Claims (1)

【特許請求の範囲】 断面が楕円形の光ビームの投光器から投光される光ビー
ムを集光レンズを介して被測定物体上にスポットを結ぶ
ように当てて、その乱反射光を他の集光レンズを介して
集光し所定の位置に配置された受光位置検出器に当てて
、その受光位置検出器の検出結果から前記被測定物体ま
での距離または前記被測定物体の変位を測定する光学式
測長方法において、 前記被測定物体上に当たる楕円形のスポットの長軸を、
前記両集光レンズの夫々の光軸を含む面に対して垂直な
方向に一致させて、長さ1.5mm〜3.0mmにした
ことを特徴とする光学式測長方法。
[Claims] A light beam projected from a light beam projector with an elliptical cross section is directed onto an object to be measured through a condenser lens so as to connect the spots, and the diffusely reflected light is reflected by another condenser. An optical type that focuses light through a lens and hits a light receiving position detector placed at a predetermined position to measure the distance to the object to be measured or the displacement of the object to be measured from the detection result of the light receiving position detector. In the length measurement method, the long axis of the elliptical spot on the object to be measured is
An optical length measuring method, characterized in that both of the condenser lenses are aligned in a direction perpendicular to a plane containing their respective optical axes, and have a length of 1.5 mm to 3.0 mm.
JP63011546A 1988-01-20 1988-01-20 Optical measuring method Expired - Fee Related JP2717250B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP63011546A JP2717250B2 (en) 1988-01-20 1988-01-20 Optical measuring method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP63011546A JP2717250B2 (en) 1988-01-20 1988-01-20 Optical measuring method

Publications (2)

Publication Number Publication Date
JPH01185410A true JPH01185410A (en) 1989-07-25
JP2717250B2 JP2717250B2 (en) 1998-02-18

Family

ID=11780959

Family Applications (1)

Application Number Title Priority Date Filing Date
JP63011546A Expired - Fee Related JP2717250B2 (en) 1988-01-20 1988-01-20 Optical measuring method

Country Status (1)

Country Link
JP (1) JP2717250B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009085745A (en) * 2007-09-28 2009-04-23 Sunx Ltd Height-measuring instrument for bga solder ball
WO2022190522A1 (en) * 2021-03-10 2022-09-15 オムロン株式会社 Triangulating displacement sensor
CN117029689A (en) * 2023-10-07 2023-11-10 武汉大学 Laser triangulation system and tunnel scanning method using same

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57104803A (en) * 1980-12-20 1982-06-30 Anritsu Corp Displacement measuring apparatus

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57104803A (en) * 1980-12-20 1982-06-30 Anritsu Corp Displacement measuring apparatus

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009085745A (en) * 2007-09-28 2009-04-23 Sunx Ltd Height-measuring instrument for bga solder ball
WO2022190522A1 (en) * 2021-03-10 2022-09-15 オムロン株式会社 Triangulating displacement sensor
CN117029689A (en) * 2023-10-07 2023-11-10 武汉大学 Laser triangulation system and tunnel scanning method using same
CN117029689B (en) * 2023-10-07 2024-01-05 武汉大学 Laser triangulation system and tunnel scanning method using same

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Publication number Publication date
JP2717250B2 (en) 1998-02-18

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