JPH0344504A - Method and apparatus for measuring three-dimensional shape of surface - Google Patents
Method and apparatus for measuring three-dimensional shape of surfaceInfo
- Publication number
- JPH0344504A JPH0344504A JP17796589A JP17796589A JPH0344504A JP H0344504 A JPH0344504 A JP H0344504A JP 17796589 A JP17796589 A JP 17796589A JP 17796589 A JP17796589 A JP 17796589A JP H0344504 A JPH0344504 A JP H0344504A
- Authority
- JP
- Japan
- Prior art keywords
- measured
- light
- glass
- light source
- measuring
- 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
Links
- 238000000034 method Methods 0.000 title claims description 17
- 239000011521 glass Substances 0.000 abstract description 30
- 238000005259 measurement Methods 0.000 abstract description 7
- 230000001678 irradiating effect Effects 0.000 abstract 1
- 239000000126 substance Substances 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 5
- 238000001579 optical reflectometry Methods 0.000 description 5
- 230000003287 optical effect Effects 0.000 description 4
- 238000003384 imaging method Methods 0.000 description 3
- 239000000523 sample Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000005357 flat glass Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
Landscapes
- Length Measuring Devices By Optical Means (AREA)
Abstract
Description
【発明の詳細な説明】
【産業上の利用分野】
本発明は表面三次元形状測定方法及びその装置に関する
ものである。
［従来の技術］
従来の板ガラス、曲面ガラス等の三次元形状測定は、接
触式プローブを対象物体表面に沿って点計測を繰り返し
、その形状を求める方式が一般的である。しかし、この
方法は、測定時間が長く、また接触による対象物体の形
状変化を免れないという欠点を有していた。
［発明の解決しようとする課題］
このような欠点を解消するため、非接触の表面三次元形
状測定法がいくつか提案されている。
その一つとして、格子パターンを対象物体に投影し、物
体上の格子パターンから物体の形状を求める方法が提案
されているが、これは対象物体表面が粗面であることを
必要としたため、ガラスの様な光反射性を有する物体に
は適用できなかった。又、光反射性を有する面の表面形
状測定方法及び装置としては、特開昭５６−１５８９０
４号により板状部材の面角度測定方法が提案されている
。この方法、装置では板状部材にレーザー光線を直接投
射し、その反射角度を発光装置付近に設けられたマトリ
ックス状に配列された受光装置により検知し、面傾斜角
度を求めている。つまり、この方法、装置ではレーザー
光の指向性が高いため、測定対象物の形状が発光、受光
装置の位置によって限定される。
そのため、複雑な形状をした測定対象物を測定するには
、数多くの受光装置が必要となるという問題を有してい
た。
［課題を解決するための手段］
本発明は前述の課題を解決すべくなされたものであり、
光を反射する面を有する被測定物表面に、実質的に点状
であって複数のあるいは移動可能な散乱光源から発せら
れた光を照射し、その反射光線を光入射方向を特定し得
る受光装置で受光し、上記光源及び受光装置の位置、上
記光入射方向並びに被測定物と受光装置の概略距離から
被測定物表面の傾きを知ることによって被測定物の表面
三次元形状を測定することを特徴とする表面三次元形状
測定方法及びその装置を提供するものである。
［作用］
本発明においては、光の反射方向を測定することにより
、光反射を有する被測定物の表面三次元形状を測定する
際、光源として位置が既知の実質的に点状の散乱光源を
用いているため、受光装置を多数必要とすることがなく
、能率良く、被測定物の表面三次元形状が測定し得るも
のである。
［実施例］
以下に本発明の１つの実施例について説明する。第１図
は本発明の基本的構成の概略的斜視図であり、１は被測
定物のガラス、２は点状の散乱光源で例えばスクリーン
３上にレーザスキャナー４などによって正確に位置認識
されながらレーザー光を照射したもの等が用いられる。
５はビデオ等のカメラで、点状の光源２からの光線がガ
ラスｌの表面で反射された像を撮像する。実施例におけ
る点状散乱光源２を発生させるスクリーン３の大きさは
、被測定物であるガラス１の大きさや形状、そしてガラ
ス１とスクリーン３との距離Ｌ＋、カメラ５の位置によ
って適宜選択される。具体的には、被測定物のガラス１
が例えば自動車に組み付けるサイドウィンドウ程度のも
のであれば、スクリーン３の真中にカメラ５を配置し、
カメラ５をガラス】の真上２ｍ程度の所にそれぞれを配
設するヒスクリーン３の大きさは３ｍＸ３ｍ程度となる
。本発明の装置においては被測定物のガラス１とカメラ
５との距離を大きくとることが精度向上の為望ましい。
この実施例においては光源として、スクリーン上にレー
ザー光を照射したものを用いているが、本発明において
は、光源の位置が既知であること、散乱光源であること
、及び被測定物と光源との距離を考慮して実質的に点光
源と見なせれば良いので、この方法に限る必要はない。
例えばＬＥＤ等を多数用いること、移動可能なＬＥＤ等
を用いること、さらにはガラスと光源との距離を十分に
とることにより、蛍光灯等を本発明における実質的な点
光源として用いることも可能である。
また、受光装置については、実施例においてはカメラを
用いているがビデオカメラ、ステイルカメラ等、反射光
の入射方向を特定し得るものであれば何でも良く、その
他にフォトセンサーをマトリックス状に配置したもの等
も好ましく使用できる。
以下に本発明の特徴を、光源としてスクリーン上にレー
ザー光を照射したもの、また受光装置としてビデオカメ
ラを用いた場合を例にとって詳細に説明する。
第２図は本発明の原理を示す概略図である。
スクリーン３上の散乱光源２ａ及び２ｂはそれぞれ被測
定物のガラス１上の反射像１ａ、ｌｂとしてカメラ５の
撮像面の７ａ、７ｂに撮像し、カメラ５の視線方向５ａ
、５ｂの方向に認識される。カメラ５より、視線方向５
ａの方向に見える反射像１ａの位置におけるガラス面角
度ａはカメラ５の視点６の位置、散乱光源２ａの位置、
スクリーン３と反射像１８間の概略距離Ｌ□及びカメラ
５から反射像１ａを見る時の視線方向５ａとによって求
められる。同様にして反射像１ｂの位置におけるガラス
面角度すもカメラ５の視点６の位置、散乱光源２ｂの位
置、スクリーン３と反射像ｌｂ間の距離Ｌ３及びカメラ
５から反射像１ｂを見る時の視線方向５ｂとによって求
められる。ここで距離Ｌ１は距離Ｌ２と反射像１ａにお
ける面角度ａ１反射像１ａ、ｌｂ間の距離Ｌ４から近似
計算により得て、用いることができるので測定する必要
がない。本発明の方式においては、測定対象物の位置例
えば距離Ｌ２についての要求測定精度は従来方法におい
て、粗面に格子パターンを投影して被測定物の表面三次
元形状を測定する時に測定対象物までの距離測定精度が
測定機そのものの精度を決定するのに比べて、大変ゆる
く、通常１ｍｍ程度である。また、反射像の見える視線
方向を正確に同定するためにあらかじめ熱線反射ガラス
等の反射体を用いて、光学系に起因する画像歪を考慮す
るのが好ましい。このときは、位置の分かった熱線反射
ガラス等の反射板を形状測定されるガラスに近接して、
あるいはガラスの代わりに設置し、スクリーン上で座標
が既知の輝点がこのガラス面で反射してビデオカメラ等
の光学系の撮像面のどの位置に結像するのかを測定する
ことにより、反射光のカメラへの入射方向と撮像位置と
の関係を知ることができる。この方法によれば、受光装
置の光学系に起因する歪を考慮した形で、ガラスからの
光の反射方向を得ることができるので、−層の精度の向
上が可能である。
本発明にかかる実施例の装置の概要を第３図の概念図と
して示す。被測定物であるガラスは試料台８上に設置し
、レーザスキャナー４によってスクリーン３上に散乱光
源を発生させる。この時、被測定物であるガラス１上に
生ずる散乱光源の反射像の位置をあらかじめ位置のわか
っているカメラ５によって測定する。各々の散乱光源の
位置とスクリーン３と被測定物であるガラス１上の１点
までの概略距離Ｌ１とをあらかじめ知っていることによ
り、散乱光源の反射像が生じたガラス面上における法線
な求めることができ、それらを連続化することにより被
測定物全面における三次元形状を非接触に測定すること
が可能となる。
本発明の装置を用いてブラウン管用大型パネルについて
その三次元形状を測定した。スクリーンの大きさを２０
００ｍｍＸ １５００＋＋ｏｎ、被測定物とスクリーン
の距離を１５００ｍｍとしてブラウン管用大型パネルの
一部分を測定し、その結果を従来の接触式三次元形状測
定機で測定した結果と比較すると、両者の差として１７
０μｍが得られた。これにより本装置による光反射性を
有する面の表面三次元形状測定法の有効性が確認された
。
以上１本実施例において被測定物としてはガラスを例と
しているが、表面が光反射性を有する物体であれば、こ
れに限らないことは当然である。
［発明の効果］
以上のように本発明によれば、板状及び曲面の光反射性
を有する試料を光の反射性を利用することによって非接
触で測定することができるため、被測定物の形状を変形
させることなく、そのままの状態での測定を正確に行な
うことができる。また、より高精度な測定を行なう場合
にはスクリーンと被測定物との距離を離すことによって
行なえる。
本発明においては、光源として実質的に点状の散乱光源
を用いているため、受光装置の数を減らして装置全体を
簡略化し得る。
また、請求項２にかかる発明によれば、受光゛装置の光
学系に起因する歪を考慮した形でガラスからの光の反射
方向を得ることができるので、−層の精度の向上が可能
である。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for measuring a three-dimensional surface shape. [Prior Art] Conventional three-dimensional shape measurement of plate glass, curved glass, etc. is generally performed by repeatedly measuring points along the surface of the target object using a contact probe to obtain the shape. However, this method has the disadvantage that the measurement time is long and the shape of the target object inevitably changes due to contact. [Problems to be Solved by the Invention] In order to eliminate such drawbacks, several non-contact surface three-dimensional shape measurement methods have been proposed. One method that has been proposed is to project a grid pattern onto the target object and determine the shape of the object from the grid pattern on the object, but this method requires the target object surface to be rough, so It could not be applied to objects with light reflectivity such as. In addition, a method and apparatus for measuring the surface shape of a surface having light reflectivity is disclosed in Japanese Patent Application Laid-open No. 56-15890.
No. 4 proposes a method for measuring the surface angle of a plate-like member. In this method and device, a laser beam is directly projected onto a plate-shaped member, and the angle of reflection of the laser beam is detected by a light receiving device arranged in a matrix provided near the light emitting device to determine the surface inclination angle. In other words, in this method and apparatus, since the laser beam has high directivity, the shape of the object to be measured is limited by the positions of the light emitting and light receiving devices. Therefore, there has been a problem in that a large number of light receiving devices are required to measure a measuring object having a complicated shape. [Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems,
Light emitted from a plurality of substantially point-shaped or movable scattered light sources is irradiated onto the surface of an object to be measured that has a light-reflecting surface, and the reflected light beam is received so that the direction of light incidence can be determined. Measuring the three-dimensional shape of the surface of the object to be measured by receiving light with a device and determining the inclination of the surface of the object from the positions of the light source and light receiving device, the direction of light incidence, and the approximate distance between the object and the light receiving device. The present invention provides a three-dimensional surface shape measuring method and an apparatus thereof, which are characterized by the following. [Function] In the present invention, when measuring the three-dimensional shape of the surface of an object having light reflection by measuring the direction of light reflection, a substantially point-shaped scattered light source with a known position is used as the light source. Therefore, the three-dimensional shape of the surface of the object to be measured can be efficiently measured without requiring a large number of light receiving devices. [Example] One example of the present invention will be described below. FIG. 1 is a schematic perspective view of the basic configuration of the present invention, in which 1 is a glass object to be measured, 2 is a point-like scattered light source, and the position is accurately recognized on a screen 3 by a laser scanner 4, etc. A material irradiated with laser light is used. Reference numeral 5 denotes a camera such as a video camera, which captures an image of the light rays from the point-like light source 2 reflected on the surface of the glass l. The size of the screen 3 that generates the point scattered light source 2 in the embodiment is appropriately selected depending on the size and shape of the glass 1 that is the object to be measured, the distance L+ between the glass 1 and the screen 3, and the position of the camera 5. . Specifically, the glass 1 of the object to be measured
For example, if the screen is a side window installed in a car, the camera 5 is placed in the middle of the screen 3,
The size of the screen 3, in which the camera 5 is placed about 2 m directly above the glass, is about 3 m x 3 m. In the apparatus of the present invention, it is desirable to increase the distance between the glass 1 of the object to be measured and the camera 5 in order to improve accuracy. In this example, a light source that irradiates a laser beam onto a screen is used, but in the present invention, the position of the light source is known, the light source is a scattered light source, and the distance between the object to be measured and the light source is It is not necessary to be limited to this method, as it is sufficient if the distance between the two points is taken into account and the light source can be regarded as a point light source. For example, by using a large number of LEDs, etc., by using movable LEDs, and by keeping a sufficient distance between the glass and the light source, it is possible to use a fluorescent lamp or the like as a substantial point light source in the present invention. be. In addition, as for the light receiving device, although a camera is used in the embodiment, any device such as a video camera, a still camera, etc. that can identify the direction of incidence of the reflected light may be used.In addition, a photo sensor may be arranged in a matrix. It is also possible to use these materials preferably. The features of the present invention will be described in detail below, taking as an example a case in which a screen is irradiated with laser light as a light source, and a video camera is used as a light receiving device. FIG. 2 is a schematic diagram illustrating the principle of the invention. The scattered light sources 2a and 2b on the screen 3 capture reflected images 1a and lb on the glass 1 of the object to be measured on the imaging planes 7a and 7b of the camera 5, respectively, and the line of sight direction 5a of the camera 5.
, 5b. From camera 5, line of sight direction 5
The glass surface angle a at the position of the reflected image 1a seen in the direction a is the position of the viewpoint 6 of the camera 5, the position of the scattered light source 2a,
It is determined by the approximate distance L□ between the screen 3 and the reflected image 18 and the viewing direction 5a when viewing the reflected image 1a from the camera 5. Similarly, the glass surface angle at the position of the reflected image 1b, the position of the viewpoint 6 of the camera 5, the position of the scattered light source 2b, the distance L3 between the screen 3 and the reflected image 1b, and the line of sight when viewing the reflected image 1b from the camera 5. direction 5b. Here, the distance L1 can be obtained by approximate calculation from the distance L2 and the surface angle a1 in the reflected image 1a, the distance L4 between the reflected images 1a and lb, and can be used, so there is no need to measure it. In the method of the present invention, the required measurement accuracy for the position of the object to be measured, for example, the distance L2, is different from that in the conventional method when measuring the three-dimensional shape of the surface of the object by projecting a grating pattern onto a rough surface. The distance measurement accuracy is much looser than the accuracy of the measuring device itself, which is usually about 1 mm. Furthermore, in order to accurately identify the line-of-sight direction in which the reflected image is visible, it is preferable to use a reflector such as a heat-reflecting glass in advance and to take into account image distortion caused by the optical system. At this time, place a reflective plate such as heat ray reflective glass whose position is known close to the glass whose shape is to be measured.
Alternatively, it can be installed in place of glass, and the reflected light can be measured by measuring where a bright spot with known coordinates on the screen is reflected from the glass surface and formed on the imaging surface of an optical system such as a video camera. It is possible to know the relationship between the direction of incidence of the image on the camera and the imaging position. According to this method, the direction of reflection of light from the glass can be obtained in a manner that takes into account the distortion caused by the optical system of the light receiving device, so that it is possible to improve the precision of the -layer. An outline of an apparatus according to an embodiment of the present invention is shown as a conceptual diagram in FIG. A glass object to be measured is placed on a sample stage 8, and a laser scanner 4 generates a scattered light source on the screen 3. At this time, the position of the reflected image of the scattered light source generated on the glass 1, which is the object to be measured, is measured by the camera 5 whose position is known in advance. By knowing in advance the position of each scattered light source and the approximate distance L1 between the screen 3 and a point on the glass 1 that is the object to be measured, it is possible to determine the normal line on the glass surface where the reflected image of the scattered light source is generated. By making them continuous, it becomes possible to measure the three-dimensional shape over the entire surface of the object in a non-contact manner. The three-dimensional shape of a large cathode ray tube panel was measured using the apparatus of the present invention. Set the screen size to 20
When measuring a part of a large cathode ray tube panel with a distance of 00mm x 1500++ on and a distance of 1500mm between the object to be measured and the screen, and comparing the results with those measured using a conventional contact type three-dimensional shape measuring machine, the difference between the two was 17.
0 μm was obtained. This confirmed the effectiveness of the method of measuring the three-dimensional surface shape of a surface with light reflectivity using this device. Although glass is used as an example of the object to be measured in this embodiment, it is of course not limited to this as long as the object has a surface that reflects light. [Effects of the Invention] As described above, according to the present invention, it is possible to measure a plate-like or curved sample having light reflectivity without contact by utilizing the light reflectivity. Measurements can be made accurately without changing the shape. Further, when performing a measurement with higher precision, it can be performed by increasing the distance between the screen and the object to be measured. In the present invention, since a substantially point-like scattered light source is used as a light source, the number of light receiving devices can be reduced and the entire device can be simplified. Further, according to the invention according to claim 2, since the direction of light reflection from the glass can be obtained in a manner that takes into account distortion caused by the optical system of the light receiving device, it is possible to improve the accuracy of the -layer. be.
図面は本発明の一実施例を示し、第１図は表面三次元形
状測定装置の基本的構成の概略的斜視図、第２図は本発
明の概念図、第３図は本発明の装置の概略斜視図である
。尚、図面中１はガラス、２は点状散乱光源、３はスク
リーン。
４は散乱光発生装置、５はカメラ、６はカメラの視点、
７は受光位置である。
第
図The drawings show an embodiment of the present invention; FIG. 1 is a schematic perspective view of the basic configuration of a three-dimensional surface shape measuring device, FIG. 2 is a conceptual diagram of the present invention, and FIG. 3 is a diagram of the device of the present invention. It is a schematic perspective view. In the drawings, 1 is glass, 2 is a point scattered light source, and 3 is a screen. 4 is a scattered light generator, 5 is a camera, 6 is a viewpoint of the camera,
7 is a light receiving position. Diagram
Claims (3)
に点状であって複数のあるいは移動可能な散乱光源から
発せられた光を照射し、その反射光線を光入射方向を特
定し得る受光装置で受光し、上記光源及び受光装置の位
置、上記光入射方向並びに被測定物と受光装置の概略距
離から被測定物表面の傾きを知ることによって被測定物
の表面三次元形状を測定することを特徴とする表面三次
元形状測定方法。(1) The surface of the object to be measured, which has a light-reflecting surface, is irradiated with light emitted from a plurality of substantially point-shaped or movable scattered light sources, and the reflected light beam is used to identify the direction of light incidence. The three-dimensional shape of the surface of the object to be measured is determined by detecting the light with a light receiving device that can be A method for measuring a three-dimensional surface shape.
を測定するに際し、あらかじめ位置と表面形状の知られ
た光反射板による反射光の受光装置への入射方向と受光
装置における受光位置との関係を測定しておくことによ
って、反射光の受光装置における受光位置から反射光の
受光装置への入射方向を精度良く知ることを特徴とする
表面三次元形状測定方法。(2) When measuring the three-dimensional shape of the surface of the object to be measured by the method of claim 1, the incident direction of the light reflected by the light reflecting plate whose position and surface shape are known in advance to the light receiving device and the light receiving position in the light receiving device. A three-dimensional surface shape measuring method characterized in that the direction of incidence of reflected light on a light receiving device can be accurately determined from the light receiving position of the reflected light on the light receiving device by measuring the relationship between the two.
状を測定する装置であって、複数のあるいは移動可能の
実質的に点状の散乱光源と、該光源から発せられて被測
定物表面で反射された光の入射方向を特定し得る受光装
置とを有することを特徴とする表面三次元形状測定装置
。(3) A device for measuring the three-dimensional shape of the surface of an object to be measured having a surface that reflects light, which includes a plurality of or movable substantially point-shaped scattered light sources and a object to be measured emitted from the light sources. 1. A three-dimensional surface shape measuring device, comprising: a light receiving device capable of specifying the incident direction of light reflected on an object surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17796589A JP2737271B2 (en) | 1989-07-12 | 1989-07-12 | Surface three-dimensional shape measuring method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17796589A JP2737271B2 (en) | 1989-07-12 | 1989-07-12 | Surface three-dimensional shape measuring method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0344504A true JPH0344504A (en) | 1991-02-26 |
| JP2737271B2 JP2737271B2 (en) | 1998-04-08 |
Family
ID=16040174
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17796589A Expired - Fee Related JP2737271B2 (en) | 1989-07-12 | 1989-07-12 | Surface three-dimensional shape measuring method and device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2737271B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5568258A (en) * | 1992-08-25 | 1996-10-22 | Asahi Glass Company Ltd. | Method and device for measuring distortion of a transmitting beam or a surface shape of a three-dimensional object |
| US6980291B2 (en) | 2002-08-01 | 2005-12-27 | Asahi Glass Company, Limited | Method of and apparatus for inspecting a curved shape |
| JP2013040971A (en) * | 2009-02-24 | 2013-02-28 | Corning Inc | Method for measuring shape of specular reflection surface |
-
1989
- 1989-07-12 JP JP17796589A patent/JP2737271B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5568258A (en) * | 1992-08-25 | 1996-10-22 | Asahi Glass Company Ltd. | Method and device for measuring distortion of a transmitting beam or a surface shape of a three-dimensional object |
| US6980291B2 (en) | 2002-08-01 | 2005-12-27 | Asahi Glass Company, Limited | Method of and apparatus for inspecting a curved shape |
| JP2013040971A (en) * | 2009-02-24 | 2013-02-28 | Corning Inc | Method for measuring shape of specular reflection surface |
| JP2016040559A (en) * | 2009-02-24 | 2016-03-24 | コーニング インコーポレイテッド | Measurement of shape of specular reflection surface |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2737271B2 (en) | 1998-04-08 |
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