JPS6249563B2 - - Google Patents
Info
- Publication number
- JPS6249563B2 JPS6249563B2 JP4294581A JP4294581A JPS6249563B2 JP S6249563 B2 JPS6249563 B2 JP S6249563B2 JP 4294581 A JP4294581 A JP 4294581A JP 4294581 A JP4294581 A JP 4294581A JP S6249563 B2 JPS6249563 B2 JP S6249563B2
- Authority
- JP
- Japan
- Prior art keywords
- target object
- slit
- scanning line
- cathode ray
- ray tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000006243 chemical reaction Methods 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 9
- 238000005259 measurement Methods 0.000 description 8
- 238000001514 detection method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000003111 delayed effect Effects 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
- G01B11/25—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures by projecting a pattern, e.g. one or more lines, moiré fringes on the object
- G01B11/2518—Projection by scanning of the object
- G01B11/2522—Projection by scanning of the object the position of the object changing and being recorded
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
- G01B11/25—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures by projecting a pattern, e.g. one or more lines, moiré fringes on the object
- G01B11/2518—Projection by scanning of the object
Description
本発明は、曲面形状を有する物体のある基準位
置からの等高位置を計測し、結果的にその物体の
形状を測定する方法に関するものである。
従来、モアレ縞を利用して立体形状を測定する
方法は知られているが、このモアレ方式では対象
物体の形状を等高線に相当する縞によつて表示で
きるとしても対象物体が凸または凹のいずれの方
向に変形しているのか不明で、且つまた精度のよ
い測定を行うことができない。
本発明は、このような問題を解決した物体形状
の測定方法を提供しようとするものであり、特に
機械的駆動部のない簡単な構成を採用し、また短
時間に対象物体の形状測定を行えるようにしたこ
とを特徴とするものである。
本発明の詳細な説明に先立ち、まず、第１図及
び第２図を参照して本発明の基本的な測定原理に
ついて説明する。
第１図において、測定対象物体Ｏに対設したス
リツト光源の移動面Ｎ上においてスリツト光源
（スリツトは紙面に直角）をn0，n1，n2，………
と一定ピツチで移動させ、それに伴つてスリツト
光の投射方向を例えば投影レンズの中心点Ｐのま
わりに回転させると、そのスリツト光が対象物体
Ｏ上の点A0，A1，A2，………を照射し、それら
の各点A0，A1，A2，………が対象物体Ｏの等高
面上にある場合には、各点からの反射光が受光レ
ンズの中心点Ｑを通して光電変換面Ｍ上に結像す
る際に、m0，m1，m2，………のような一定のピ
ツチの位置に像を結ぶことになる。逆に、m0，
m1，m2，………の各点が一定ピツチで配列しな
いときは、対象物体上の点A0，A1，A2，………
が等高面上に存在しないことになり、従つて凹凸
のある対象物体上に上記スリツト光を投射して、
その反射光を光電変換面Ｍ上に結像させると、第
２図に示すように、対象物体の表面の凹凸に応じ
て湾曲した像I0，I1，I2，………が得られること
になる。而して、n0，n1，n2，………の位置にあ
るスリツト光源からの光で順次I0，I1，I2，……
…の像が得られるとき、順次m0，m1，m2，……
…の位置を走査してその走査線との交点a0，a1，
a2，………，b0，b1，b2，………を求めると、こ
れらの点群がすべて等高線上にあり、その接続に
よつて等高線を得ることができる。
また、上記スリツト光の像I0，I1，I2，………
と走査線との対応関係を変化させれば、第１図中
に点線で示すように、異なる等高面上の点群
B0，B1，………を求めることができる。
本発明は、このような原理を用いて対象物体上
における等高位置を求めようとするものであり、
前記モアレ方式に比して対象物体が凸または凹の
いずれの方向に変形しているのかを明確にした形
状測定を行うことができ、また特に機械的駆動部
のない簡単な構成により短時間に対象物体の形状
測定を行うことができるものである。
即ち、本発明の測定方法は、ブラウン管の管面
にスリツト像を明るく表示してこれをレンズ系で
対象物体上に投影することによりスリツト光と
し、対象物体からの上記スリツト光の反射光を光
電変換器の変換面に結像させ、その変換面の走査
により各走査線と反射光の像との交点のデータを
各走査開始点からの時間として検出し、このデー
タに基づいて対象物体の等高線を得ることを特徴
とするものである。
図面を参照してさらに具体的に説明すると、第
３図に示すように、本発明におけるスリツト光源
としてはブラウン管１０を用い、その管面１１と
光電変換器２０の変換面２１は同一平面上または
平行平面上に位置させる。また、上記ブラウン管
１０の走査線と光電変換器２０の走査線は平行に
配設する。
上記ブラウン管１０は、その管面１１に走査線
に沿うスリツト像１２を明るく表示し、これをレ
ンズ系（図示せず）で対象物体に投影することに
よりスリツト光とし、このスリツト光をブラウン
管の管面１１で横方向に電子的に動かすものであ
る。このようなスリツト光は、例えばスライドプ
ロジエクタ等を回転させたり、レーザスポツトを
回転ミラーで振らせることによつても得ることが
できるが、これらの場合には精密な機構を精度よ
く駆動する必要があり、これに対して上述のブラ
ウン管１０による方法は機械的駆動部分がなく、
極めて容易にスリツト光を高速で移動させること
ができる。
一方、上記光電変器２０は、上述のスリツト光
の対象物体表面における反射光を検出するもの
で、ブラウン管１０及び光電変換器２０における
走査線の番号をそれぞれｎi，ｍjとすると、一つ
の走査線ｎiによるスリツト光に対して、像の走
査はｍp〜ｍtの全走査線によつて管面全体にわた
つて行う。而して、ｍjの各走査線についてｎiの
スリツトの像との交点のデータを、各走査開始点
からの時間として検出し、これを順次メモリに記
憶させる。なお、ｍjの走査線が像と交らないと
きは時間データをメモリに蓄積しない。
第４図は上述の時間データの検出を行うための
回路構成を示すもので、これを第５図ａ〜ｆの信
号波形との関連において以下に説明する。
まず、各走査開始ごとに第５図ａの走査開始信
号を発生させ、時間計測用のカウンタをリセツト
スタートさせる。カウンタで計数するクロツクと
しては、パルス発振器からの基準クロツク信号を
用いる。一方、前記光電変換器における走査によ
り得られる第５図ｂのビデイオ信号は、高周波ノ
イズをローパスフイルタで除去した後、微分回路
と信号検出回路に送る。微分回路は、第５図ｂの
ようなビデイオ信号の微分により、そのピーク位
置に対応して０をよこぎる同図ｃのような微分信
号を発生させ、また信号検出回路はコンパレータ
によつてビデイオ信号のピーク位置付近のみが１
となる第５図ｅの信号を発生させるものである。
上記微分回路の出力は、０交叉検出器において、
第５図ｄに示すように微分波形の０をよこぎる点
に対応して１から０に変る信号とし、これをアン
ド回路において信号検出回路の出力とのアンドを
とり、第５図ｆのような信号を得る。この信号
は、１から０に変る時点がビデイオ信号のピーク
に対応するものであり、これが投影スリツト先の
像の中心に対応している。従つて、その信号の立
下りで前述のカウンタの内容をラツチ回路にラツ
チさせる。また、同一の立下り信号からラツチ完
了に余裕をみこんだ時間だけ遅延させた信号を計
算機へデータ読込み指令として送ればよい。この
間にもカウンタは次の像に備えてカウントを続け
る。
このようにして光電変換器の変換面のすべてに
ついて走査が完了すると、スリツト光の位置を次
の位置へずらせ、これを順次繰返してブラウン管
の管端まで達したときにデータの計測は終了す
る。
なお、第４図中に付したａ〜ｆの記号は、第５
図におけるａ〜ｆの波形を示している。
上記測定によつて得られた時間データｔiは、
次の表に示すように、ブラウン管上のスリツト光
及び光電変換器における走査線の番号ｎi，ｍjと
共にセツトとして計算機のメモリ内に格納され
る。
The present invention relates to a method of measuring the contour position of an object having a curved surface shape from a certain reference position and, as a result, measuring the shape of the object. Conventionally, a method for measuring three-dimensional shapes using moiré fringes is known, but in this moiré method, even if the shape of the target object can be displayed by stripes corresponding to contour lines, it is difficult to determine whether the target object is convex or concave. It is unclear whether the deformation is occurring in the direction of , and accurate measurement cannot be performed. The present invention aims to provide a method for measuring the shape of an object that solves these problems, and in particular adopts a simple configuration without a mechanical drive unit and can measure the shape of a target object in a short time. It is characterized by the following. Prior to a detailed description of the present invention, first, the basic measurement principle of the present invention will be explained with reference to FIGS. 1 and 2. In FIG. 1, the slit light source (the slit is perpendicular to the plane of the paper) is positioned at n 0 , n 1 , n 2 ,...
When the slit light is moved at a constant pitch and the projection direction of the slit light is rotated, for example, around the center point P of the projection lens, the slit light will move to points A 0 , A 1 , A 2 , . . . on the target object O. ..., and if each of these points A 0 , A 1 , A 2 , ... is on the contour plane of the target object O, the reflected light from each point will be reflected at the center point Q of the light-receiving lens. When an image is formed on the photoelectric conversion surface M through the lens, the image is formed at a constant pitch position such as m 0 , m 1 , m 2 , . . . . Conversely, m 0 ,
When the points m 1 , m 2 , ...... are not arranged at a constant pitch, the points A 0 , A 1 , A 2 , ...... on the target object
does not exist on a contour plane, therefore, by projecting the above slit light onto an uneven target object,
When the reflected light is imaged on the photoelectric conversion surface M, images I 0 , I 1 , I 2 , etc. curved according to the unevenness of the surface of the target object are obtained as shown in Fig. 2. It turns out. Thus, the light from the slit light sources located at n 0 , n 1 , n 2 , ...... is sequentially I 0 , I 1 , I 2 , ...
When images of ... are obtained, sequentially m 0 , m 1 , m 2 , ...
Scan the position of ... and find the intersection a 0 , a 1 ,
When a 2 , ......, b 0 , b 1 , b 2 , ...... are found, all of these points are on the contour line, and the contour line can be obtained by connecting them. In addition, the images of the slit light I 0 , I 1 , I 2 , ......
By changing the correspondence between
B 0 , B 1 , ...... can be found. The present invention attempts to find a contour position on a target object using such a principle,
Compared to the Moiré method, it is possible to perform shape measurements that clearly determine whether the object is deformed in a convex or concave direction, and in particular, the simple structure without any mechanical drive means that it can be carried out in a short time. It is capable of measuring the shape of a target object. That is, the measurement method of the present invention brightly displays a slit image on the tube surface of a cathode ray tube, projects it onto a target object using a lens system to generate slit light, and converts the reflected light of the slit light from the target object into a photoelectron. The image is formed on the conversion surface of the converter, and by scanning the conversion surface, data at the intersection of each scanning line and the reflected light image is detected as the time from the start point of each scan, and based on this data, the contour line of the target object is detected. It is characterized by obtaining the following. To explain more specifically with reference to the drawings, as shown in FIG. 3, a cathode ray tube 10 is used as the slit light source in the present invention, and the tube surface 11 and the conversion surface 21 of the photoelectric converter 20 are on the same plane or Place it on a parallel plane. Further, the scanning line of the cathode ray tube 10 and the scanning line of the photoelectric converter 20 are arranged in parallel. The cathode ray tube 10 brightly displays a slit image 12 along a scanning line on its tube surface 11, and projects this onto a target object using a lens system (not shown) to produce slit light. It is electronically moved laterally on the surface 11. Such slit light can also be obtained, for example, by rotating a slide projector or by swinging a laser spot with a rotating mirror, but in these cases it is necessary to drive a precise mechanism with high precision. In contrast, the method using the cathode ray tube 10 described above does not have a mechanically driven part,
It is extremely easy to move the slit light at high speed. On the other hand, the photoelectric transformer 20 detects the reflected light of the slit light on the surface of the target object, and if the scanning line numbers in the cathode ray tube 10 and the photoelectric converter 20 are respectively n i and m j , one In contrast to the slit light beam by the scanning line n i , the image is scanned over the entire tube surface by all the scanning lines m p to m t . Then, data at the intersection of each scan line m j with the image of the slit n i is detected as the time from the start point of each scan, and this is sequentially stored in the memory. Note that when the scanning line of m j does not intersect with the image, time data is not stored in the memory. FIG. 4 shows a circuit configuration for detecting the above-mentioned time data, which will be explained below in relation to the signal waveforms shown in FIGS. 5a to 5f. First, at the start of each scan, the scan start signal shown in FIG. 5a is generated to reset and start the time measurement counter. A reference clock signal from a pulse oscillator is used as the clock counted by the counter. On the other hand, the video signal shown in FIG. 5b obtained by scanning with the photoelectric converter is sent to a differentiation circuit and a signal detection circuit after high frequency noise is removed by a low-pass filter. The differentiating circuit generates a differential signal as shown in Fig. 5c, which crosses 0 in accordance with the peak position of the video signal by differentiating the video signal as shown in Fig. 5b, and the signal detection circuit generates a differential signal as shown in Fig. Only near the peak position of the signal is 1
The signal shown in FIG. 5e is generated.
The output of the above-mentioned differentiating circuit is transmitted to the zero-crossing detector as follows:
As shown in Figure 5 d, a signal that changes from 1 to 0 corresponding to the point where the differential waveform crosses 0 is created, and this is ANDed with the output of the signal detection circuit in an AND circuit, as shown in Figure 5 f. get a signal. The point at which this signal changes from 1 to 0 corresponds to the peak of the video signal, and this corresponds to the center of the image beyond the projection slit. Therefore, the contents of the counter mentioned above are latched by the latch circuit at the falling edge of the signal. Alternatively, a signal delayed from the same falling signal by a time that allows for a margin for latch completion may be sent to the computer as a data read command. During this time, the counter continues counting in preparation for the next image. When the scanning of all the conversion surfaces of the photoelectric converter is completed in this way, the position of the slit light is shifted to the next position, and this is repeated in sequence until the data measurement ends when it reaches the end of the cathode ray tube. Note that the symbols a to f in FIG.
Waveforms a to f in the figure are shown. The time data t i obtained by the above measurement is
As shown in the following table, the slit light on the cathode ray tube and the scanning line numbers n i and m j of the photoelectric converter are stored as a set in the memory of the computer.
【表】
上述の方法は、光電変換器における変換面上の
像をすべて画像として計測する場合に比べれば、
画像処理時間を著しく短縮することが可能であ
り、また等高面を示す等高線も簡単に得ることが
できる。即ち、計算機のメモリから、スリツト光
の位置を示す番号ｎiと走査線位置を示す番号ｍj
が、ｎi＋ｍj＝ｋ（ｋは等高線の光電変換面から
の距離を決定する値）という線形関係を満すもの
を検索することにより、簡単に等高面上のデータ
を得ることができ、このようにして得られた一連
の点について、走査線位置ｘ座標、時間データを
ｙ座標として、ｘ−ｙ表面等に表示すれば、これ
らの点を結ぶ曲線として等高線が求められる。
なお、等高面の間隔及び同一の等高面上での検
出点間距離は、面Ｎ，Ｍと点Ｐ，Ｑの位置関係に
よつて定まり、従つてそれらの間を計測するに
は、スリツト移動面Ｎあるいは光電変換面での走
査線位置を、走査線間隔内でずらせばよい。この
方法をとることにより、任意の等高面で対象物体
を切断した断面の任意な点を容易に計測すること
が可能となる。[Table] Compared to the case where the above method measures all images on the conversion surface of a photoelectric converter as images,
Image processing time can be significantly shortened, and contour lines representing contour surfaces can also be easily obtained. That is, from the memory of the computer, a number n i indicating the position of the slit beam and a number m j indicating the scanning line position are obtained.
However, by searching for a line that satisfies the linear relationship n i + m j = k (k is the value that determines the distance of the contour line from the photoelectric conversion surface), it is possible to easily obtain data on the contour surface. If the series of points thus obtained are displayed on an x-y surface, etc., with the scanning line position x coordinate and time data as the y coordinate, contour lines can be obtained as curves connecting these points. Note that the interval between contour planes and the distance between detection points on the same contour plane are determined by the positional relationship between planes N and M and points P and Q. Therefore, in order to measure between them, The scanning line position on the slit moving surface N or the photoelectric conversion surface may be shifted within the scanning line interval. By using this method, it becomes possible to easily measure an arbitrary point on a cross section of the target object cut along an arbitrary contour plane.
第１図及び第２図は本発明の測定原理について
の説明図、第３図は本発明において用いるブラウ
ン管及び光電変換器の斜視図、第４図は上記光電
変換器に接続して時間データの計測を行う回路の
構成図、第５図ａ〜ｆは上記回路の各部における
信号の波形図である。
１０……ブラウン管、１１……管面、１２……
スリツト像、２０……光電変換器、２１……変換
器。
Figures 1 and 2 are explanatory diagrams of the measurement principle of the present invention, Figure 3 is a perspective view of the cathode ray tube and photoelectric converter used in the present invention, and Figure 4 is a diagram showing the connection of the photoelectric converter to the time data. FIGS. 5a to 5f, a block diagram of a circuit for performing measurement, are waveform diagrams of signals at each part of the circuit. 10... Braun tube, 11... Tube surface, 12...
Slit image, 20... photoelectric converter, 21... converter.
Claims (1)
してこれをレンズ系で対象物体上に投影すること
によりスリツト光とし、上記ブラウン管の管面と
同一または平行平面上に位置する光電変換器の変
換面における走査線を上記ブラウン管の走査線と
平行に配設し、対象物体上に投影した上記スリツ
ト光の反射光を光電変換器の変換面に結像させ、
その変換面の走査により各走査線と反射光の像と
の交点のデータを各走査開始点からの時間として
検出し、このデータに基づいて対象物体の等高線
を得ることを特徴とする物体形状の測定方法。1. A slit image is brightly displayed on the surface of the cathode ray tube and is projected onto the target object using a lens system to produce slit light, and a conversion surface of a photoelectric converter located on the same or parallel plane as the surface of the cathode ray tube. a scanning line is disposed parallel to the scanning line of the cathode ray tube, and the reflected light of the slit light projected onto the target object is imaged on a conversion surface of a photoelectric converter;
By scanning the conversion surface, data at the intersection of each scanning line and the reflected light image is detected as the time from each scanning start point, and contour lines of the target object are obtained based on this data. Measuring method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4294581A JPS57157107A (en) | 1981-03-24 | 1981-03-24 | Method for measuring shape of object |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4294581A JPS57157107A (en) | 1981-03-24 | 1981-03-24 | Method for measuring shape of object |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57157107A JPS57157107A (en) | 1982-09-28 |
| JPS6249563B2 true JPS6249563B2 (en) | 1987-10-20 |
Family
ID=12650143
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4294581A Granted JPS57157107A (en) | 1981-03-24 | 1981-03-24 | Method for measuring shape of object |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57157107A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61264204A (en) * | 1985-05-20 | 1986-11-22 | Fujitsu Ltd | Detector for height of parts |
| US5156089A (en) * | 1990-12-17 | 1992-10-20 | Gerber Scientific Products, Inc. | Method and apparatus for making a painting screen using an ink jet printer for printing a graphic on the screen emulsion |
| US5668631A (en) | 1993-12-20 | 1997-09-16 | Minolta Co., Ltd. | Measuring system with improved method of reading image data of an object |
| US6407817B1 (en) | 1993-12-20 | 2002-06-18 | Minolta Co., Ltd. | Measuring system with improved method of reading image data of an object |
| JP3341549B2 (en) | 1995-11-14 | 2002-11-05 | ミノルタ株式会社 | 3D shape data processing device |
-
1981
- 1981-03-24 JP JP4294581A patent/JPS57157107A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57157107A (en) | 1982-09-28 |
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