CN101539595A - Machine-vision lighting system - Google Patents
Machine-vision lighting system Download PDFInfo
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- CN101539595A CN101539595A CN200910083235A CN200910083235A CN101539595A CN 101539595 A CN101539595 A CN 101539595A CN 200910083235 A CN200910083235 A CN 200910083235A CN 200910083235 A CN200910083235 A CN 200910083235A CN 101539595 A CN101539595 A CN 101539595A
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- 230000003287 optical effect Effects 0.000 claims abstract description 19
- 230000010287 polarization Effects 0.000 claims abstract description 11
- 238000001228 spectrum Methods 0.000 claims description 18
- 238000005286 illumination Methods 0.000 claims description 14
- 230000005540 biological transmission Effects 0.000 claims description 4
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Abstract
The invention relates to a machine-vision lighting system, belonging to the technical field of machine vision. The machine-vision lighting system comprises a light source, a polarizer, an optical filter, an analyzer and an image shooting device. The light source is arranged in front of a lighted object; the polarizer is arranged between the light source and the lighted object, wherein, the light source and the polarizer form a lighting beam path; the image shooting device, the analyzer and the optical filter are arranged in sequence to form a receiving beam path; the included angle between the receiving beam path and the lighting beam path is alpha, wherein, alpha is more than 0 degree and less than 180 degrees. The machine-vision lighting system of the invention utilizes differences between polarization characteristics of a specular reflection light and a diffuse reflection light, thereby preventing the diffuse reflection light from transmitting the specular reflection light; therefore, the machine-vision lighting system not only ensures enough lighting, but also avoids reflection influence caused by the surface of an object. Therefore, the machine-vision lighting system is not only applicable to image-shooting equipment, but also applicable to cameras for overcoming reflection caused by a flash light.
Description
Technical field
The present invention relates to a kind of machine-vision lighting system, belong to the machine vision technique field.
Background technology
Illuminator is one of parts of Vision Builder for Automated Inspection most critical, its main target be with suitable manner with ray cast to testee, the contrast of outstanding tested feature, its performance quality is directly connected to the success or failure of total system.Good design can improve the resolution of total system, simplifies the computing of software.A reliable and stable image processing system can not only be confined to obtain momentary qualitative picture in the laboratory, the more important thing is to obtain image high-quality, high-contrast at the practical application scene.In order to realize this reliable and stable image processing system, the quality that improves lighting source is most important.Inappropriate illumination can cause a lot of problems, and for example: if it is very high to be identified the object surface smoothness, its reflective meeting causes the serious decline of picture quality, greatly limits the recognition effect of machine vision; The reflective meeting of glasses causes the inefficacy of human eye recognizer etc.To every kind of different detected object, must adopt different lighting systems could give prominence to the feature of measurand, need combination in several ways sometimes.
The light illumination conceptual design should be given prominence to the characteristic quantity of object as much as possible, produces significantly difference between part that object need detect and those unessential parts as far as possible, increases contrast.Light source also should guarantee enough overall brightnesses in addition, and the variation of object space should not influence image quality.For this reason, each developed country competitively launches the research of machine vision light source, as AI (Advanced illumination) company of the CCS company of Japan and MORITEX commercial firm, the U.S. etc., succeed in developing series high-performance machine vision light source, as: direct illumination light source (shower mode, bar shaped mode, low angle mode, optically focused mode etc.), indirect lighting light source (flat, annular mode, dome mode etc.), transillumination mode (mode backlight, linear mode etc.), coaxial-illuminating light source etc.Can see also simultaneously that the design of machine vision light source mainly is in order to realize even illumination, seldom to consider the reflective of testee surface at present.And under some operating mode, such as: vision system is used for the higher body surface quality testing of smooth finish, occasions such as wearing spectacles personnel's eyes identification, surface reflection can make picture quality seriously descend, even causes the inefficacy of whole vision system.Therefore, the needs development is a kind of can prevent from again to cause reflective lighting engineering because of direct reflection for machine vision provides adequate illumination.
Summary of the invention
The objective of the invention is to overcome the reflective machine-vision lighting system of body surface, overcome the reflective influence of body surface, simplify the software computing machine vision picture quality in order to provide a kind of.
The machine-vision lighting system that the present invention proposes, comprise: light source, the polarizer, optical filter, analyzer, image-pickup device, described light source places the place ahead of illuminated object, and the described polarizer places between light source and the illuminated object, and the light source and the polarizer constitute illumination path; Described image-pickup device, analyzer and optical filter are arranged in order, and constitute receiving light path, and the angle of this light path and described illumination path is α, 0 °＜α＜180 °.
In the said lighting system, image-pickup device is video camera or camera.When image-pickup device is video camera, also comprise image pick-up card and computing machine, described image pick-up card is connected with video camera, and described computing machine is connected with image pick-up card.
In the said lighting system, the light transmission shaft direction of analyzer is arranged to object direct reflection light polarization direction perpendicular.
In the said lighting system, light source is the white light source of spectrum at the 0.38-0.76 mu m range, described optical filter is the white light optical filter of spectrum at the 0.38-0.76 mu m range, and the described polarizer and analyzer are respectively the white light polaroid of spectrum at the 0.38-0.76 mu m range.
In the said lighting system, light source is the near-infrared light source of spectrum at the 0.76-1.1 mu m range, described optical filter is the near infrared filter of spectrum at the 0.76-1.1 mu m range, and the described polarizer and analyzer are the near infrared polarization sheet of spectrum at the 0.76-1.1 mu m range.
The machine-vision lighting system that the present invention proposes, its advantage is:
1, utilized specular light and the difference of the polarization characteristic that diffuses, reach and isolate the purpose that the direct reflection transmittance diffuses, not only guaranteed adequate illumination but also overcome the reflective influence of body surface.
2, applied widely.This technology not only can be used for picture pick-up device, also may be used on being used in the camera overcome reflective that flashlamp causes.
Description of drawings
Fig. 1 is the structure principle chart of system of the present invention.
Fig. 2 is an application example of system of the present invention.
Among Fig. 1 and Fig. 2, the 1st, light source; The 2nd, the polarizer, the 3rd, illuminated object, the 4th, optical filter, the 5th, analyzer, the 6th, image-pickup device, the 7th, video camera, the 8th, image pick-up card, the 9th, computing machine.
Embodiment
The machine-vision lighting system that the present invention proposes, its structure comprises as shown in Figure 1: light source 1, the polarizer 2, optical filter 4, analyzer 5, image-pickup device 6.Light source 1 places the place ahead of illuminated object 3, and the polarizer 2 places between light source and 1 illuminated object 3, and the light source 1 and the polarizer 2 constitute illumination path.Image-pickup device 6, analyzer 5 and optical filter 4 are arranged in order, and constitute receiving light path, and the angle of this light path and described illumination path is α, 0 °＜α＜180 °.
In the said lighting system, image-pickup device can be video camera or camera.When being video camera as capturing apparatus, also comprise image pick-up card and computing machine, described image pick-up card is connected with video camera, and described computing machine is connected with image pick-up card.As shown in Figure 2.
In the said lighting system, the light transmission shaft direction of analyzer is arranged to object direct reflection light polarization direction perpendicular.
In the said lighting system, light source is the white light source of spectrum at the 0.38-0.76 mu m range, described optical filter is the white light optical filter of spectrum at the 0.38-0.76 mu m range, and the described polarizer and analyzer are respectively the white light polaroid of spectrum at the 0.38-0.76 mu m range.
In the said lighting system, light source is the near-infrared light source of spectrum at the 0.76-1.1 mu m range, described optical filter is the near infrared filter of spectrum at the 0.76-1.1 mu m range, and the described polarizer and analyzer are the near infrared polarization sheet of spectrum at the 0.76-1.1 mu m range.
The principle of work of system of the present invention is:
Light that light source 1 sends is through the polarizer 2 polarization light output, this linearly polarized light irradiating object 3 and by object 3 surface reflections.Reflected light is divided into two parts, and a part is for diffusing, and a part is a specular light.Direct reflection only causes the reflective reason of body surface, be arranged to the light transmission shaft direction of analyzer 5 vertical with the direct reflection light polarization direction, just can be isolated in specular light outside the imaging optical path, utilize specular light still to keep the characteristic of linear polarization here.Its principle can be described with fresnel formula:
In the formula: E, R represent incident light, reflected light respectively, and subscript p and s represent to be parallel to the oscillating component of the plane of incidence respectively and perpendicular to the oscillating component of the plane of incidence, θ
1And θ
2Be respectively incident angle and refraction angle.R
sRelatively and E
s, R
pWith respect to E
pPhase change is 0 ° or 180 °, because E
sAnd E
pFrequency identical, phasic difference is 0, so R
sAnd R
pPhase differential be stable at 0 ° or 180 °, remain linearly polarized light.
And from the diffusing owing to belong to natural light or partial poolarized light of body surface, so its major part can see through analyzer and image on the imageing sensor.This just guarantee machine-vision lighting system of the present invention can provide sufficient illumination can prevent again because of direct reflection cause reflective.
Provided by the inventionly can overcome the reflective machine-vision lighting system of body surface, its operation is carried out as follows:
(1) polarizer 2 is fixed on the output terminal of light source, only makes to be parallel to the axial linearly polarized light output of printing opacity;
(2) light source 1 is aimed at measured target, Real Time Observation image from the image-pickup device is regulated light source output brightness, and is suitable up to brightness of image;
(3) rotate analyzer 5, and from the computing machine the Real Time Observation image, the reflective disappearance up to the testee surface;
(4) position of fixed light source 1, camera 7, the polarizer 2 and analyzer 5.
Claims (6)
1, a kind of machine-vision lighting system, it is characterized in that this illuminator comprises: light source, the polarizer, optical filter, analyzer, image-pickup device, described light source places the place ahead of illuminated object, the described polarizer places between light source and the illuminated object, and the light source and the polarizer constitute illumination path; Described image-pickup device, analyzer and optical filter are arranged in order, and constitute receiving light path, and the angle of this light path and described illumination path is α, 0 °＜α＜180 °.
2, illuminator as claimed in claim 1 is characterized in that wherein said image-pickup device is video camera or camera.
3, illuminator as claimed in claim 2 when it is characterized in that wherein image-pickup device is video camera, also comprises image pick-up card and computing machine, and described image pick-up card is connected with video camera, and described computing machine is connected with image pick-up card.
4, illuminator as claimed in claim 1 is characterized in that the light transmission shaft direction of wherein said analyzer is arranged to object direct reflection light polarization direction perpendicular.
5, illuminator as claimed in claim 1, it is characterized in that wherein said light source is the white light source of spectrum at the 0.38-0.76 mu m range, described optical filter is the white light optical filter of spectrum at the 0.38-0.76 mu m range, and the described polarizer and analyzer are respectively the white light polaroid of spectrum at the 0.38-0.76 mu m range.
6, illuminator as claimed in claim 1, it is characterized in that wherein said light source is the near-infrared light source of spectrum at the 0.76-1.1 mu m range, described optical filter is the near infrared filter of spectrum at the 0.76-1.1 mu m range, and the described polarizer and analyzer are the near infrared polarization sheet of spectrum at the 0.76-1.1 mu m range.
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| Application Number | Priority Date | Filing Date | Title |
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| CN200910083235A CN101539595A (en) | 2009-04-30 | 2009-04-30 | Machine-vision lighting system |
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| CN200910083235A CN101539595A (en) | 2009-04-30 | 2009-04-30 | Machine-vision lighting system |
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| CN101539595A true CN101539595A (en) | 2009-09-23 |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102436573A (en) * | 2011-07-15 | 2012-05-02 | 东莞市中控电子技术有限公司 | Image acquisition and recognition device with active illumination function |
| CN105136059A (en) * | 2015-05-26 | 2015-12-09 | 东莞市盟拓光电科技有限公司 | Three-dimensional measuring system capable of reducing light reflection on surface of measured object |
| CN107241592A (en) * | 2016-06-29 | 2017-10-10 | 鲁班嫡系机器人 | A kind of projecting unit and filming apparatus, processor, imaging device including the unit |
| CN107643292A (en) * | 2016-07-20 | 2018-01-30 | 南京造币有限公司 | A kind of surface detection apparatus and its method based on liquid-crystalline glasses |
| CN109580638A (en) * | 2018-12-07 | 2019-04-05 | 华中科技大学 | A kind of the appearance detection system and method for small-sized smooth surface moulding |
| CN110428637A (en) * | 2019-07-24 | 2019-11-08 | 华为技术有限公司 | A kind of road gate grasp shoot method and road gate capturing system |
-
2009
- 2009-04-30 CN CN200910083235A patent/CN101539595A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102436573A (en) * | 2011-07-15 | 2012-05-02 | 东莞市中控电子技术有限公司 | Image acquisition and recognition device with active illumination function |
| CN105136059A (en) * | 2015-05-26 | 2015-12-09 | 东莞市盟拓光电科技有限公司 | Three-dimensional measuring system capable of reducing light reflection on surface of measured object |
| CN107241592A (en) * | 2016-06-29 | 2017-10-10 | 鲁班嫡系机器人 | A kind of projecting unit and filming apparatus, processor, imaging device including the unit |
| WO2018001252A1 (en) * | 2016-06-29 | 2018-01-04 | 鲁班嫡系机器人 | Projection unit and photographing apparatus comprising same projection unit, processor, and imaging device |
| CN107241592B (en) * | 2016-06-29 | 2020-08-11 | 鲁班嫡系机器人 | Imaging device and imaging method |
| CN107643292A (en) * | 2016-07-20 | 2018-01-30 | 南京造币有限公司 | A kind of surface detection apparatus and its method based on liquid-crystalline glasses |
| CN107643292B (en) * | 2016-07-20 | 2021-05-04 | 南京造币有限公司 | Surface detection device and method based on liquid crystal glass |
| CN109580638A (en) * | 2018-12-07 | 2019-04-05 | 华中科技大学 | A kind of the appearance detection system and method for small-sized smooth surface moulding |
| CN110428637A (en) * | 2019-07-24 | 2019-11-08 | 华为技术有限公司 | A kind of road gate grasp shoot method and road gate capturing system |
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