JPH054024B2 - - Google Patents
Info
- Publication number
- JPH054024B2 JPH054024B2 JP14870186A JP14870186A JPH054024B2 JP H054024 B2 JPH054024 B2 JP H054024B2 JP 14870186 A JP14870186 A JP 14870186A JP 14870186 A JP14870186 A JP 14870186A JP H054024 B2 JPH054024 B2 JP H054024B2
- Authority
- JP
- Japan
- Prior art keywords
- liquid crystal
- inspection
- pattern
- lighting
- illumination
- 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
Links
- 239000004973 liquid crystal related substance Substances 0.000 claims description 37
- 238000007689 inspection Methods 0.000 claims description 27
- 238000000149 argon plasma sintering Methods 0.000 claims description 17
- 239000011159 matrix material Substances 0.000 claims description 15
- 230000003287 optical effect Effects 0.000 claims description 10
- 238000005286 illumination Methods 0.000 description 17
- 238000000034 method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000011179 visual inspection Methods 0.000 description 5
- 230000010287 polarization Effects 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 230000007547 defect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000003384 imaging method Methods 0.000 description 3
- 230000002950 deficient Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011265 semifinished product Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/47—Scattering, i.e. diffuse reflection
- G01N21/4738—Diffuse reflection, e.g. also for testing fluids, fibrous materials
- G01N21/474—Details of optical heads therefor, e.g. using optical fibres
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
本発明は立体物等の検査対象物を照明して、こ
の対象物の疵や欠陥を検査する外観自動検査の照
明装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an illumination device for automatic appearance inspection that illuminates an object to be inspected, such as a three-dimensional object, to inspect the object for flaws or defects.
従来の技術
生産工程中の外観自動検査はあらゆる製品・半
製品に適用され、製品の良・不良を判別してい
る。この外観検査項目は、それぞれの製品が具備
すべき性能・特性に応じて種々雑多であるが、大
別すると製品の色や汚れなど物体色に関する検査
項目と割れ・打こんなど形状に関する検査項目に
わけられる。Conventional technology Automatic visual inspection during the production process is applied to all products and semi-finished products to determine whether the product is good or defective. These visual inspection items vary widely depending on the performance and characteristics that each product should have, but they can be roughly divided into inspection items related to object color such as product color and dirt, and inspection items related to shape such as cracks and dents. It can be divided.
このうち、物体色の検査については紙やシート
材の一部のように検査対象物の形状が平面で、拡
散反射特性をもつものについては、検査用照明の
方向性（照射角）に関して大きな問題とならな
い。 Among these, when it comes to inspecting object color, there is a big problem with the directionality (irradiation angle) of the inspection lighting when the inspection object is flat and has diffuse reflection characteristics, such as a part of paper or sheet material. Not.
しかし、鏡面性を帯びているものについては、
どんな投光照射を行なつてもこの対象物の画像パ
ターンには必らず正反射成分の輝点がいくつか現
われ、この画像を処理して色や汚れを検出するの
に多くの検査アルゴリズムと時間を要する。そこ
でこの欠点をなくするため、通常は第４図に示す
ように検査対象物のあらゆる方向から光を照射す
る拡散照明を行ない、輝度の発生を防いている。 However, for objects with specularity,
No matter what type of floodlight is used, the image pattern of this object will always contain some bright spots of specular reflection components, and many inspection algorithms are required to process this image and detect color and dirt. It takes time. In order to eliminate this drawback, diffuse illumination is normally used to irradiate the object to be inspected from all directions, as shown in FIG. 4, to prevent the occurrence of brightness.
一方、検査対象物の割れや打こんを検査しよう
とすると上記の拡散照明では検査・判別に有効な
輝度パターンが現われない。そこで、一方向から
光を照射する投光照明方式をとつて割れや打こん
によつて生ずる陰影を強調し、疵検出を容易にし
ている。この投光照明の照射方向は検査対象物に
より、また同じ対象物でも疵の種類に応じて変え
る必要があり、第５図に示すように投光照明装置
を機械的に動かす方法がとられてきた。また、ス
リツトパターンやグリツド（格子）パターンを投
影して、これによる画像を処理することにより、
外観自動検査のアルゴリズムの簡易化と検査スピ
ードの向上をはかろうとするパターン照明も、上
記照明装置とは別に実施されてきた。 On the other hand, when attempting to inspect an object to be inspected for cracks or dents, the above-mentioned diffused illumination does not produce a brightness pattern that is effective for inspection and discrimination. Therefore, a flood lighting system that emits light from one direction is used to emphasize the shadows caused by cracks and dents, making it easier to detect defects. The irradiation direction of this floodlight needs to be changed depending on the object to be inspected, and even on the same object depending on the type of flaw, so a method of mechanically moving the floodlight device as shown in Figure 5 has been adopted. Ta. In addition, by projecting a slit pattern or a grid pattern and processing the resulting image,
Pattern illumination, which aims to simplify the algorithm for automatic appearance inspection and improve inspection speed, has also been implemented separately from the above-mentioned illumination devices.
発明が解決しようとする問題点
このように、一つの検査対象物に対して多種の
外観検査を実施しようとすると、それぞれの検査
目的に応じて照明装置や撮像装置を必要とし、検
査に要する時間も長くなるなど外観自動検査用照
明装置として実用性に乏しいという問題を有して
いた。Problems to be Solved by the Invention In this way, when attempting to perform various visual inspections on one inspection object, lighting devices and imaging devices are required depending on the purpose of each inspection, and the time required for inspection is However, there were problems in that it was not practical as a lighting device for automatic appearance inspection, such as the length of the lighting device.
本発明は、このような従来の問題を解消するも
ので、拡散照明、投光照明およびパターン照明を
簡単な構成で電気的に、短時間のうちに切換える
ことができる。外観自動検査用照明装置を実現す
ることを目的としている。 The present invention solves these conventional problems, and allows diffuse lighting, floodlight lighting, and pattern lighting to be switched electrically in a short time with a simple configuration. The purpose is to realize a lighting device for automatic appearance inspection.
問題点を解決するための手段
本発明は上記問題点を解決するため、検査対象
物に照射可能な全立体角に配置した、光源、液晶
シヤツタマトリツクス、偏光板、投影レンズおよ
び光散乱液晶素子からなる複数個の投影光学系ユ
ニツトと、これらの液晶シヤツタマトリツクスと
光散乱液晶素子を制御する液晶駆動制御部とから
構成している。Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a light source, a liquid crystal shutter matrix, a polarizing plate, a projection lens, and a light-scattering liquid crystal arranged in all solid angles capable of irradiating the object to be inspected. It consists of a plurality of projection optical system units each consisting of a plurality of elements, and a liquid crystal drive control section that controls these liquid crystal shutter matrices and light scattering liquid crystal elements.
作 用
本発明は上記の構成とすることにより、液晶シ
ヤツタマトリツクスと光散乱液晶素子を電気的に
制御して、拡散照明、投光照明、パターン照明お
よびこれらの併存した照明を高速時分割で選択提
示を可能とするものである。Effects By having the above configuration, the present invention electrically controls the liquid crystal shutter matrix and the light scattering liquid crystal element, and performs diffuse illumination, flood illumination, pattern illumination, and illumination that coexists with these at high speed time division. This allows for selective presentation.
実施例
第１図は本発明の外観自動検査用照明装置の一
実施例を示すもので、光源１から出た光は液晶シ
ヤツタマトリツクス２を経て偏光板３、投影レン
ズ４、光散乱液晶素子５を通過してのち検査対象
物６に照射される。ここで、光源１、液晶シヤツ
タマトリツクス２、偏光板３、投影レンズ４、光
散乱液晶素子５が投影光学系ユニツトを構成す
る。Embodiment FIG. 1 shows an embodiment of the lighting device for automatic appearance inspection of the present invention, in which light emitted from a light source 1 passes through a liquid crystal shutter matrix 2, a polarizing plate 3, a projection lens 4, and a light scattering liquid crystal. After passing through the element 5, the object to be inspected 6 is irradiated. Here, the light source 1, liquid crystal shutter matrix 2, polarizing plate 3, projection lens 4, and light scattering liquid crystal element 5 constitute a projection optical system unit.
液晶シヤツタマトリツクス２はツイストモード
で動作し、第２図のように２１，２２，２３の各
パターンが独立あるいは同時に、それぞれの偏光
面を90゜変えることができる。このため、液晶シ
ヤツタマトリツクスが動作している時の偏光面と
偏光板３の偏光面とを直交させておけば、液晶シ
ヤツタマトリツクスの各パターンに電圧を印加し
て偏光面を90゜変えた時、光は透過し、そのパタ
ーンに応じた像が検査対象物に照射されることに
なる。 The liquid crystal shutter matrix 2 operates in a twist mode, and as shown in FIG. 2, each of the patterns 21, 22, and 23 can change the plane of polarization by 90 degrees, either independently or simultaneously. Therefore, if the polarization plane when the liquid crystal shutter matrix is in operation is made orthogonal to the polarization plane of the polarizing plate 3, a voltage can be applied to each pattern of the liquid crystal shutter matrix to change the polarization plane by 90 degrees. When the angle is changed, light is transmitted and an image corresponding to the pattern is irradiated onto the object to be inspected.
したがつて、これらの投影光学系ユニツトを検
査対象物６の周りに２次元的に配置し、第２図の
２１あるいは２２のどちらかを単独で動作させる
と、検査対象物の表面には上記２１あるいは２２
の線状パターンが互いに重畳されて連続しスリツ
トパターンが生ずることになる。もし、第２図の
２１と２２を同時に動作させると検査対象物の表
面には十字パターンが重畳されて連続しグリツド
パターン（格子パターン）が現われる。 Therefore, if these projection optical system units are two-dimensionally arranged around the inspection object 6 and either 21 or 22 in FIG. 21 or 22
The linear patterns are superimposed on each other to form a continuous slit pattern. If 21 and 22 in FIG. 2 are operated simultaneously, a cross pattern is superimposed on the surface of the object to be inspected, and a continuous grid pattern appears.
さらに、一部の投影光学系ユニツトについて、
第２図の２１，２２，２３のすべてを動作させる
と、一定方向からの投光照明が可能になる。 Furthermore, for some projection optical system units,
When all of 21, 22, and 23 in FIG. 2 are operated, floodlighting from a fixed direction becomes possible.
このようにして、液晶シヤツタマトリツクスの
動作パターンを電気的に制御することにより、ス
リツトパターンやグリツドパターンなどのパター
ン照明と、一定角度からの投光照明を容易に変更
できる。 By electrically controlling the operation pattern of the liquid crystal shutter matrix in this manner, pattern illumination such as a slit pattern or grid pattern and flood illumination from a fixed angle can be easily changed.
しかし、検査対象物が球面でその表面が鏡面性
を帯びている時、検査対象物の画像パターンには
動作している投影光学系の数だけ輝点が生ずるこ
とになる。これをなくするため投影レンズ４と検
査対象物６の間に光散乱液晶素子５を挿入し、こ
れに電圧を印加することにより、光散乱現象を起
させる。同時に、すべての投影光学系ユニツトの
すべての液晶マトリツクスパターンを動作させ
る。これにより各投影光学系から出た光はすべて
光散乱液晶素子上で散乱され、検査対象物は完全
な拡散照明で照射されることになる。この場合第
１図に示すように、各投影光学系ユニツトの光散
乱液晶素子５は四角形とし、互に接するように配
置する必要がある。また拡散照明中で一部の光散
乱液晶素子の印加電圧を０にすることによりパタ
ーン照明との併用が可能になる。なお、投影レン
ズ４に分布屈折率レンズアレーを用いると、液晶
シヤツタマトリツクス２から検査対象物６までの
物像間距離を小さくすることができ、照明装置全
体を一体化するのに有力となる。 However, when the object to be inspected is spherical and has a specular surface, as many bright spots as there are operating projection optical systems are generated in the image pattern of the object to be inspected. In order to eliminate this, a light scattering liquid crystal element 5 is inserted between the projection lens 4 and the object to be inspected 6, and a voltage is applied to it to cause a light scattering phenomenon. At the same time, all liquid crystal matrix patterns of all projection optical system units are operated. As a result, all the light emitted from each projection optical system is scattered on the light scattering liquid crystal element, and the object to be inspected is illuminated with complete diffused illumination. In this case, as shown in FIG. 1, the light scattering liquid crystal elements 5 of each projection optical system unit must be square and arranged so as to be in contact with each other. Also, by setting the applied voltage to some of the light scattering liquid crystal elements to 0 during diffused illumination, it is possible to use it in combination with patterned illumination. Note that if a distributed index lens array is used for the projection lens 4, the object-to-image distance from the liquid crystal shutter matrix 2 to the inspection object 6 can be reduced, which is effective for integrating the entire illumination device. Become.
このほか、これらの複数の液晶シヤツタマトリ
ツクス２のそれぞれと、光散乱液晶素子５の印加
電圧をアナログ的に変えることにより照射光量を
変えることができ、また各投影光学系ユニツト７
の動作を個々に制御することにより投光照明と拡
散照明の混合照明が可能となり、検査対象物の必
要とする検査項目にもつとも適合した照射パター
ンが選択でき、一つの対象物に対する検査項目の
多くを同時または短時間に実施できる特徴をも
つ。 In addition, the amount of irradiation light can be changed by analogically changing the voltage applied to each of the plurality of liquid crystal shutter matrices 2 and the light scattering liquid crystal element 5.
By individually controlling the operation of the , it is possible to mix floodlight and diffused lighting, and it is possible to select an irradiation pattern that is suitable for the inspection items required for the inspection object, and it is possible to select the irradiation pattern that is suitable for the inspection items required for the inspection object. It has the characteristic that it can be carried out simultaneously or in a short period of time.
この照明装置はまた、疵の判別結果をフイード
バツクして照明方法の優先順位を変えていく、い
わゆる学習効果をもつた外観検査システムを実現
するうえで有力な装置となる。第３図は、上記の
外観検査システムの全体を示すもので撮像素子９
の画像信号をうけて画像処理判別部１４が必要と
定めた照明方法を液晶駆動制御部１３に伝え、光
散乱液晶素子５および液晶シヤツタマトリツクス
の双方が動作して検査対象物６の照明方法を順次
変えていく制御の流れを示している。 This lighting device will also be a powerful device in realizing a visual inspection system with a so-called learning effect, which feeds back the results of defect discrimination and changes the priority order of lighting methods. FIG. 3 shows the entire appearance inspection system described above, and shows the image sensor 9.
Upon receiving the image signal, the image processing determination section 14 transmits the illumination method determined as necessary to the liquid crystal drive control section 13, and both the light scattering liquid crystal element 5 and the liquid crystal shutter matrix operate to illuminate the inspection object 6. It shows the flow of control that changes the method sequentially.
発明の効果
本発明による外観自動検査用照明装置は、光
源、液晶シヤツタマトリツクス、偏光板、投影レ
ンズおよび光散乱液晶素子をもつ投影光学系ユニ
ツトを互いに光散乱液晶素子が接するように併置
し、これらの液晶シヤツタマトリツクスおよび光
散乱液晶素子の双方を電気的に制御することによ
り、拡散照明、投光照明、パターン照明およびこ
れらの併存した照明方式を時分割で選択提示する
ことができ、極めて汎用性の高い外観検査用照明
装置として、その実用的価値はまことに大きい。Effects of the Invention The lighting device for automatic appearance inspection according to the present invention includes a projection optical system unit having a light source, a liquid crystal shutter matrix, a polarizing plate, a projection lens, and a light scattering liquid crystal element, which are arranged side by side so that the light scattering liquid crystal elements are in contact with each other. By electrically controlling both the liquid crystal shutter matrix and the light scattering liquid crystal element, it is possible to selectively present diffuse lighting, floodlighting, pattern lighting, and the combination of these lighting methods in a time-sharing manner. As an extremely versatile visual inspection lighting device, its practical value is truly great.
第１図は本発明による外観自動検査用照明装置
の一実施例を示す図、第２図は液晶シヤツタマト
リツクスのパターン分割の一例を示す図、第３図
は本発明による照明装置を備えた外観自動検査装
置のブロツクダイヤフラムの説明図、第４図は従
来の拡散照明方式の説明図、第５図は従来の投光
照明方式の説明図である。
８……撮像素子、９……撮像用レンズ、１０…
…拡散照明用光源、１２……投光照明装置。
FIG. 1 is a diagram showing an embodiment of a lighting device for automatic appearance inspection according to the present invention, FIG. 2 is a diagram showing an example of pattern division of a liquid crystal shutter matrix, and FIG. 3 is a diagram showing an example of a lighting device for automatic appearance inspection according to the present invention. FIG. 4 is an explanatory diagram of a conventional diffused lighting system, and FIG. 5 is an explanatory diagram of a conventional floodlight system. 8...imaging element, 9...imaging lens, 10...
...Light source for diffused illumination, 12...Floodlight device.
Claims (1)
投影レンズおよび光散乱液晶素子からなる複数個
の投影光学系ユニツトと、前記複数個の液晶シヤ
ツタマトリツクスおよび光散乱液晶素子を電気的
に制御する液晶駆動制御部とから構成され、拡散
照明、投光照明およびパターン照明が電気的に切
換えられる機能を有する外観自動検査用照明装
置。1 Light source, liquid crystal shutter matrix, polarizing plate,
It is composed of a plurality of projection optical system units including a projection lens and a light-scattering liquid crystal element, and a liquid crystal drive control section that electrically controls the plurality of liquid crystal shutter matrices and the light-scattering liquid crystal element. A lighting device for automatic exterior inspection that has a function to electrically switch between floodlighting and pattern lighting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14870186A JPS635247A (en) | 1986-06-25 | 1986-06-25 | Illuminator for automatically inspecting appearance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14870186A JPS635247A (en) | 1986-06-25 | 1986-06-25 | Illuminator for automatically inspecting appearance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS635247A JPS635247A (en) | 1988-01-11 |
| JPH054024B2 true JPH054024B2 (en) | 1993-01-19 |
Family
ID=15458663
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14870186A Granted JPS635247A (en) | 1986-06-25 | 1986-06-25 | Illuminator for automatically inspecting appearance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS635247A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0421906U (en) * | 1990-06-12 | 1992-02-24 | ||
| JP4907428B2 (en) * | 2006-05-18 | 2012-03-28 | 新日本製鐵株式会社 | Surface inspection system and diagnostic method for inspection performance of surface inspection system |
| KR102292547B1 (en) | 2020-04-10 | 2021-08-20 | 코그넥스코오포레이션 | Optic system using dynamic diffuser |
-
1986
- 1986-06-25 JP JP14870186A patent/JPS635247A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS635247A (en) | 1988-01-11 |
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