JP2674129B2 - Distance measuring device - Google Patents
Distance measuring deviceInfo
- Publication number
- JP2674129B2 JP2674129B2 JP21986888A JP21986888A JP2674129B2 JP 2674129 B2 JP2674129 B2 JP 2674129B2 JP 21986888 A JP21986888 A JP 21986888A JP 21986888 A JP21986888 A JP 21986888A JP 2674129 B2 JP2674129 B2 JP 2674129B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- measured
- incident
- light receiving
- objective lens
- 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 - Lifetime
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- Measurement Of Optical Distance (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は距離測定装置、特に、光ビームを用いて被測
定面との距離を測定するものに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring device, and more particularly to a device for measuring a distance from a surface to be measured using a light beam.
（従来の技術） 従来のこの種の装置に係わる技術としては、三角測量
に基づいた特開昭52−162911号がある。(Prior Art) As a conventional technology related to this type of apparatus, there is JP-A-52-162911 based on triangulation.
このものは、レーザ光源からのレーザ光を投光レン
ズ、揺動ミラーを介して斜め方向から被測定対象面に投
光する投光光学系と、被測定対象面に光軸をほぼ垂直に
設けられた受光レンズ、及び受光レンズで集光されたレ
ーザ光を光電変換する光電変換素子を有する受光光学系
と、を有し、揺動ミラーを回転してレーザ光の被測定対
象面への入射角を変え、受光素子から得られる信号が最
大になったときの揺動ミラーの回転角θをもとめれば、
受光レンズの中心と揺動ミラーの回転中心との距離をｄ
として、受光レンズの中心と被測定対象面までの距離ｈ
はd/tanθで求めることができる。This is a projection optical system that projects laser light from a laser light source to a surface to be measured from a diagonal direction through a projection lens and an oscillating mirror, and an optical axis is provided substantially perpendicular to the surface to be measured. And a light-receiving optical system having a photoelectric conversion element for photoelectrically converting the laser light collected by the light-receiving lens, and rotating the oscillating mirror to make the laser light incident on the surface to be measured. If you change the angle and find the rotation angle θ of the oscillating mirror when the signal obtained from the light receiving element becomes maximum,
The distance between the center of the light receiving lens and the center of rotation of the swing mirror is d
As the distance h between the center of the light receiving lens and the surface to be measured
Can be calculated by d / tan θ.
（発明が解決しようとする問題点） このような三角測量に基づいた装置は、被測定対象物
へのレーザ光の投光方向と受光光学系の光軸とはある角
度をもっているので、被測定対象面が鏡面であったり、
表面荒さの小さい場合（研削面やラップ面）には、受光
光学系に反射光が返って来ず、測定不能となったり、返
って来たとしてもS/Nの非常に悪い測定となり誤差が大
きくなっていた。(Problems to be Solved by the Invention) An apparatus based on such triangulation has a certain angle between the projection direction of the laser light to the object to be measured and the optical axis of the light receiving optical system, and The target surface is a mirror surface,
When the surface roughness is small (ground surface or lapping surface), the reflected light does not return to the light receiving optical system and measurement becomes impossible, or even if it returns, the S / N becomes a very bad measurement and an error occurs. It was getting bigger.
そこで本発明は、被測定対象面の表面性状を選ばず、
すなわち、被測定対象面が拡散面であるのみならず、正
反射成分の強い金属であったり、またガラスのような鏡
面であっても、被接触にて高精度測定を実現できる装置
を提供することを目的とする。Therefore, the present invention does not select the surface texture of the surface to be measured,
That is, it is possible to provide a device capable of realizing high-precision measurement by being contacted even when the surface to be measured is not only a diffusion surface but also a metal having a strong specular reflection component or a mirror surface such as glass. The purpose is to
（問題点を解決する為の手段） 本発明は、ビームスプリッタ（１）と、前記ビームス
プリッタ（１）と被測定対象面（６）との間に配設され
る対物レンズ（２）と、前記ビームスプリッタ（１）、
前記対物レンズ（２）を介して前記被測定対象面（６）
上に光ビームを投光する光源装置（３）と、前記光源装
置（３）により投光された光ビームの前記被測定対象面
（６）での反射光を前記対物レンズ（２）、前記ビーム
スプリッタ（１）を介して入光し、反射ビームの方向を
連続的に変化させる回転反射鏡（４）と、前記回転反射
鏡（４）による反射ビームを入光し、入射ビームの大き
さを表す信号を出力する受光装置（５）と、前記入射ビ
ームの大きさが最も小さくなったときの前記入射ビーム
の位置を求め、この位置から前記測定対象面（６）の位
置に係わる信号を出力する検出装置（20）〜（27）とを
有することを特徴とする距離測定装置である。(Means for Solving Problems) The present invention includes a beam splitter (1) and an objective lens (2) arranged between the beam splitter (1) and a surface to be measured (6). The beam splitter (1),
The surface to be measured (6) through the objective lens (2)
A light source device (3) for projecting a light beam onto the upper surface, and a light beam projected by the light source device (3) for reflecting light on the measured surface (6) to the objective lens (2), A rotating reflecting mirror (4) that enters the light through a beam splitter (1) and continuously changes the direction of the reflected beam, and a reflected beam by the rotating reflecting mirror (4) enters the light and the size of the incident beam And a position of the incident beam when the size of the incident beam becomes the smallest, and a signal relating to the position of the measurement target surface (6) is obtained from this position. A distance measuring device comprising: output detecting devices (20) to (27).
（作 用） 本発明においては、被測定対象面上に光ビームを投光
する投光光学系（光源装置、ビームスプリッタ、対物レ
ンズ）と、被測定対象面からの反射光を受光する受光光
学系（対物レンズ、ビームスプリッタ、回転反射鏡、受
光装置）とを共通の対物レンズを用いることによって同
軸になすことができるので、被測定対象面が鏡面や鏡面
に近い面、すなわち、金属加工片等の金属を精度よく測
定することができ、かつ拡散面に関しては、面の傾きに
対する許容幅が大きい、という作用効果がある。(Operation) In the present invention, a projection optical system (a light source device, a beam splitter, an objective lens) for projecting a light beam on a surface to be measured, and a light receiving optical system for receiving light reflected from the surface to be measured. Since the system (objective lens, beam splitter, rotary reflecting mirror, light receiving device) can be made coaxial by using a common objective lens, the surface to be measured is a mirror surface or a surface close to the mirror surface, that is, a metal work piece. The metal and other metals can be measured with high accuracy, and the diffusion surface has a large tolerance for the inclination of the surface.
（実施例） 第１図（ａ）、（ｂ）は、本発明の実施例の光学系を
示す図であって、ビームスプリッタ１と、ビームスプリ
ッタ１と被測定対象面６との間に配設される対物レンズ
２と、ビームスプリッタ１及び対物レンズ２を介して被
測定対象面６上に光ビームを投光する光源装置３と、光
源装置３から射出された光ビームの被測定対象面６での
反射光を対物レンズ２、ビームスプリッタ１を介して入
光し、反射ビームの方向を連続的に変化させる回転反射
鏡４と、回転反射鏡４による反射ビームを入光し、入射
ビームの大きさを表す信号を出力する受光装置５と、が
示されている。(Embodiment) FIGS. 1 (a) and 1 (b) are diagrams showing an optical system of an embodiment of the present invention, in which a beam splitter 1 and a beam splitter 1 and an object surface 6 to be measured are arranged. An objective lens 2 provided, a light source device 3 for projecting a light beam onto a measured surface 6 through the beam splitter 1 and the objective lens 2, and a measured surface of a light beam emitted from the light source device 3. The reflected light at 6 enters through the objective lens 2 and the beam splitter 1, and the rotary reflecting mirror 4 that continuously changes the direction of the reflected beam, and the reflected beam by the rotary reflecting mirror 4 enters and then the incident beam And a light-receiving device 5 that outputs a signal indicating the magnitude of.
ビームスプリッタ１としては、ハーフプリズムの如き
光分割部材が用いられ、光源装置３としては、レーザ光
源、及びレーザ光源からのレーザ光を対物レンズ２と共
に第１図に示した如き細い平行ビームとして被測定対象
面に投光できるようレンズ系が設けられ、回転反射鏡４
としては、回転中心ｐによって回転もしくは揺動される
べく、モータ、ガルバノメータ等の公知の駆動装置によ
り回転駆動されるものが用いられ、受光装置としては、
CCD、PSDの如き位置検出部材が用いられている。As the beam splitter 1, a light splitting member such as a half prism is used, and as the light source device 3, a laser light source and a laser light from the laser light source are received together with the objective lens 2 as a thin parallel beam as shown in FIG. A lens system is provided so that light can be projected onto the surface to be measured, and the rotary reflecting mirror 4
As the light receiving device, a device that is rotationally driven by a known driving device such as a motor or a galvanometer so as to be rotated or swung by the rotation center p is used.
Position detection members such as CCD and PSD are used.
而して、第１図（ａ）のように、光ビームが受光装置
５の受光面上の一端にあるときに、受光装置５の受光面
上の一端と高さH1にある被測定対象面の入射光に当たっ
ている位置とが共役になっており、また、第１図（ｂ）
のように、光ビームが受光装置５の受光面上の他端にあ
るときに、受光装置５の受光面上の他端と高さH2にある
被測定対象面の入射光に当たっている位置とが共役にな
っているとすれば、第１図（ａ）の状態から回転反射鏡
４が矢印Ａの方向へ回転して、光ビームが受光装置５の
受光面上の一端から他端（Ｂ方向）へ移動すると、高さ
H1からH2にある被測定対象面の光ビームの入射位置に共
役になる受光装置５の受光面上の光ビーム入射位置が一
つあることになる。このとき、受光装置５の受光面上の
光ビームの径は最小になり、この最小光ビームの径より
も、受光幅の狭い受光装置５であれば、受光装置５から
の出力信号は最大になる。Thus, as shown in FIG. 1A, when the light beam is at one end on the light-receiving surface of the light-receiving device 5, the object to be measured located at one end on the light-receiving surface of the light-receiving device 5 and at the height H 1. It is conjugate with the position of the surface that is incident on the incident light, and FIG. 1 (b)
As described above, when the light beam is at the other end on the light receiving surface of the light receiving device 5, the other end on the light receiving surface of the light receiving device 5 and the position where it is incident on the measured surface at the height H 2 Is conjugate with each other, the rotary reflecting mirror 4 rotates in the direction of arrow A from the state of FIG. Direction), height
This means that there is one light beam incident position on the light receiving surface of the light receiving device 5 that is conjugated to the light beam incident position on the surface to be measured located from H 1 to H 2 . At this time, the diameter of the light beam on the light receiving surface of the light receiving device 5 is minimized, and if the light receiving device 5 has a light receiving width narrower than the diameter of this minimum light beam, the output signal from the light receiving device 5 is maximized. Become.
従って、受光装置からの信号の最大値を与える受光面
上の位置、もしくは回転反射鏡４の回転位置（角度）か
ら被測定対象面の高さが高さH1からH2の範囲で求まるこ
とになる。Therefore, the height of the surface to be measured can be obtained within the range of heights H 1 to H 2 from the position on the light receiving surface that gives the maximum value of the signal from the light receiving device or the rotational position (angle) of the rotary reflecting mirror 4. become.
第２図は、第１図の光学系と共に用いられる電気回路
のブロック図である。FIG. 2 is a block diagram of an electric circuit used with the optical system of FIG.
第２図において、パルス発生器20からのパルスは、CC
D50の駆動装置21に入力され、駆動装置21は周知の如く
スタートパルスS1と、このスタートパルスS1に引き続く
走査パルスS2とをCCD50に入力する。その結果、CCD50は
その光電変換部が一端から他端にわたって順次走査さ
れ、これら光電変換部の光電変換信号が時系列的にCCD5
0から出力されることになる。In FIG. 2, the pulse from the pulse generator 20 is CC
The drive device 21 of D50 inputs the start pulse S 1 and the scan pulse S 2 subsequent to the start pulse S 1 to the CCD 50 as is well known. As a result, the CCD 50 has its photoelectric conversion units sequentially scanned from one end to the other end, and the photoelectric conversion signals of these photoelectric conversion units are time-sequentially CCD5.
It will be output from 0.
一方、駆動装置21からのスタートパルスS1と走査パル
スS2とはカウンタ22にも入力され、前者はリセットパル
ス、後者の数はCCD50の光電変換部の位置を示す値とし
て用いられる。すなわち、スタートパルスにてリセット
された後のカウンタ22の計数値は、CCD50から出力され
ている光電変換信号の得られた光電変換部の番地にほか
ならない。On the other hand, the start pulse S 1 and the scanning pulse S 2 from the driving device 21 are also input to the counter 22, the former is used as a reset pulse, and the latter number is used as a value indicating the position of the photoelectric conversion unit of the CCD 50. That is, the count value of the counter 22 after being reset by the start pulse is nothing but the address of the photoelectric conversion unit where the photoelectric conversion signal output from the CCD 50 is obtained.
また、CCD50の出力信号は、サンプルホールド回路、
ローパスフィルタ23に入力されて、入射ビームの大きさ
が最も小さくなったときの光電変換部の位置に対応した
時間において、ピークを有するアナログ的な信号とな
る。ローパスフィルタ23の出力信号は微分回路24に入力
され、ピーク値においてゼロクロスとなる微分信号に変
換される。The output signal of CCD50 is
It is input to the low-pass filter 23 and becomes an analog signal having a peak at a time corresponding to the position of the photoelectric conversion unit when the size of the incident beam becomes the smallest. The output signal of the low-pass filter 23 is input to the differentiating circuit 24 and converted into a differential signal that has a zero cross at the peak value.
この微分信号は、波形整形回路25に入力され、波形整
形回路25は入力信号のゼロクロス点においてパルスを一
つ発生する。波形整形回路25から出力されるパルスはゲ
ート回路26のゲート端子に入力され、ゲート回路26の開
閉を制御する。ゲート回路26の入力端子には、カウンタ
22の計数値が入力されているから、ゲート回路26からは
波形整形回路25からパルスが生じたとき、すなわち、入
射ビームの大きさが最も小さくなったときの入射ビーム
の入射位置にある光電変換部の番地に対応した計数値が
出力されることになる。This differential signal is input to the waveform shaping circuit 25, and the waveform shaping circuit 25 generates one pulse at the zero cross point of the input signal. The pulse output from the waveform shaping circuit 25 is input to the gate terminal of the gate circuit 26 and controls the opening / closing of the gate circuit 26. The input terminal of the gate circuit 26 has a counter
Since the count value of 22 is input, the photoelectric conversion at the incident position of the incident beam when the pulse is generated from the waveform shaping circuit 25 from the gate circuit 26, that is, when the size of the incident beam becomes the smallest The count value corresponding to the address of the copy is output.
ゲート回路26から出力された計数値は、マイクロコン
ピュータ等の演算装置27によって被測定対象面の高さに
変換される。光電変換部の番地、すなわちカウンタ22の
計数値と被測定対象面の高さとは、一対一に対応してい
るから、演算装置27は予め計数値と被測定対象面の高さ
との対応表を備えており、入力された計数値に対応した
被測定対象面の高さを対応表から読み出すようにしてい
る。このようにして演算された被測定対象面の高さは、
表示装置28に表示される。The count value output from the gate circuit 26 is converted into the height of the surface to be measured by an arithmetic unit 27 such as a microcomputer. The address of the photoelectric conversion unit, that is, the count value of the counter 22 and the height of the surface to be measured have a one-to-one correspondence, so the arithmetic unit 27 previously creates a correspondence table between the count value and the height of the surface to be measured. The height of the measured surface corresponding to the input count value is read from the correspondence table. The height of the surface to be measured calculated in this way is
Displayed on the display device 28.
なお、以上の実施例では、受光装置５としてCCD50を
用いた例を上げたが、受光装置５としてはCCD50のよう
に光量と共に入射位置まで検出できるものにかぎらな
い。すなわち、回転反射鏡４の回転により光ビームが走
査する受光面の範囲をカバーするように、太陽電池のよ
うな光電変換素子を用いることもでき、この場合には、
回転反射鏡４の回転位置を知るように、回転反射鏡４に
ロータリーエンコーダの如き回転検出器を設ければよ
い。そして、受光装置５の出力信号のピーク位置におけ
る回転反射鏡４の回転位置を求めれば、この回転位置が
被測定対象面の高さに対応しているので、受光装置５の
出力信号のピーク位置における被測定対象面の高さを求
めることができる。このような構成では、受光装置５は
入射光量に応じた出力が得られるものでよく、高価なCC
DやPSDを使用せずに、安価な太陽電池等が使用でき、信
号処理系も簡素化されるので、装置全体が安価になると
いう利点がある。In the above embodiments, the CCD 50 is used as the light receiving device 5, but the light receiving device 5 is not limited to the CCD 50 that can detect the incident position together with the light amount. That is, a photoelectric conversion element such as a solar cell may be used so as to cover the range of the light receiving surface scanned by the light beam by the rotation of the rotary reflecting mirror 4. In this case,
In order to know the rotational position of the rotary reflecting mirror 4, the rotary reflecting mirror 4 may be provided with a rotation detector such as a rotary encoder. Then, if the rotational position of the rotary reflecting mirror 4 at the peak position of the output signal of the light receiving device 5 is obtained, this rotational position corresponds to the height of the surface to be measured, so the peak position of the output signal of the light receiving device 5 is obtained. The height of the surface to be measured at can be obtained. With such a configuration, the light receiving device 5 may be one that can obtain an output according to the amount of incident light, and an expensive CC
An inexpensive solar cell or the like can be used without using D or PSD, and the signal processing system can be simplified, so that there is an advantage that the entire device becomes inexpensive.
また、以上の実施例において、受光装置５の受光面の
傾きを変えることで、容易に測定感度（分解能）を変え
ることができ、さらに、測定範囲を大きく取りたい場合
にも、受光素子を長くし、回転反射鏡４の揺動範囲を大
きくするだけで済み、他の光学系等の構成要素を変更す
る必要がない。Further, in the above embodiments, the measurement sensitivity (resolution) can be easily changed by changing the inclination of the light-receiving surface of the light-receiving device 5, and the light-receiving element can be lengthened even when a large measurement range is desired. However, it is only necessary to increase the swing range of the rotary reflecting mirror 4, and it is not necessary to change other components such as the optical system.
（発明の効果） 以上のように、本発明によれば、被測定対象面に対
し、光ビームを垂直に入射し、垂直な方向から被測定対
象面での反射光を受光する構成であるので、鏡面や鏡面
に近い被測定対象面からの金属加工面等の粗面のものに
対してまで、様々な面性状の測定面の測定が行なえる。(Effects of the Invention) As described above, according to the present invention, the light beam is vertically incident on the surface to be measured, and the reflected light from the surface to be measured is received from the vertical direction. , It is possible to measure a measurement surface having various surface properties such as a mirror surface or a rough surface such as a metal working surface from a surface to be measured close to the mirror surface.
さらに、本発明では、被測定対象面の位置が変わり測
定距離が変化した場合でも、絶えず受光面上に反射ビー
ムの結像している位置があり、かつ、いつもその結像し
ている状態にて距離測定を行っているので、被測定対象
の表面性状（スペックルパターン等）の影響を最小にで
き、精度の高い測定を行うことができる。Further, according to the present invention, even when the position of the surface to be measured changes and the measurement distance changes, there is always a position where the reflected beam is imaged on the light receiving surface, and the image is always in the imaged state. Since the distance measurement is performed by using the distance measurement, it is possible to minimize the influence of the surface properties (speckle pattern, etc.) of the object to be measured, and perform highly accurate measurement.
第１図（ａ）、（ｂ）は、本発明の一実施例の距離測定
装置の光学系を示す図であって、異なる高さの被測定対
象面と共役な状態にそれぞれの光学系が設定されている
様子を示しており、第２図は、第１図（ａ）、（ｂ）の
光学系と共に用いられる電気回路のブロック図である。 （主要部分の符号の説明） １……ビームスプリッタ、 ２……対物レンズ、 ３……光源装置、 ４……回転反射鏡、 ５……受光装置。FIGS. 1 (a) and 1 (b) are diagrams showing an optical system of a distance measuring apparatus according to an embodiment of the present invention, in which each optical system is in a conjugate state with a surface to be measured having a different height. FIG. 2 is a block diagram of an electric circuit used together with the optical system shown in FIGS. 1A and 1B. (Description of symbols of main parts) 1 ... Beam splitter, 2 ... Objective lens, 3 ... Light source device, 4 ... Rotating reflecting mirror, 5 ... Light receiving device.
Claims (1)
タと被測定対象面との間に配設される対物レンズと、前
記ビームスプリッタ、前記対物レンズを介して前記被測
定対象面上に光ビームを投光する光源装置と、前記光源
装置により投光された光ビームの前記被測定対象面での
反射光を前記対物レンズ、前記ビームスプリッタを介し
て入光し、反射ビームの方向を連続的に変化させる回転
反射鏡と、前記回転反射鏡による反射ビームを入光し、
入射ビームの大きさを表す信号を出力する受光装置と、
前記入射ビームの大きさが最も小さくなったときの前記
入射ビームの位置を求め、該位置から前記測定対象面の
位置に係わる信号を出力する検出装置と、を有すること
を特徴とする距離測定装置。1. A beam splitter, an objective lens disposed between the beam splitter and a surface to be measured, and a light beam projected onto the surface to be measured via the beam splitter and the objective lens. A light source device that emits light, and light reflected by the surface to be measured of the light beam projected by the light source device enters through the objective lens and the beam splitter, and the direction of the reflected beam is continuously changed. Rotating reflecting mirror to let, and the reflected beam by the rotating reflecting mirror is incident,
A light receiving device that outputs a signal indicating the size of the incident beam,
A distance measuring device for determining a position of the incident beam when the size of the incident beam becomes the smallest and outputting a signal related to the position of the measurement target surface from the position. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21986888A JP2674129B2 (en) | 1988-09-02 | 1988-09-02 | Distance measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21986888A JP2674129B2 (en) | 1988-09-02 | 1988-09-02 | Distance measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0267911A JPH0267911A (en) | 1990-03-07 |
| JP2674129B2 true JP2674129B2 (en) | 1997-11-12 |
Family
ID=16742314
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21986888A Expired - Lifetime JP2674129B2 (en) | 1988-09-02 | 1988-09-02 | Distance measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2674129B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010197210A (en) * | 2009-02-25 | 2010-09-09 | Tokyo Gas Co Ltd | Surface shape measuring method and device therefor |
-
1988
- 1988-09-02 JP JP21986888A patent/JP2674129B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0267911A (en) | 1990-03-07 |
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