CN104360463B - Three telecentricity coaxial-illuminating imaging optical systems - Google Patents
Three telecentricity coaxial-illuminating imaging optical systems Download PDFInfo
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- CN104360463B CN104360463B CN201410728564.7A CN201410728564A CN104360463B CN 104360463 B CN104360463 B CN 104360463B CN 201410728564 A CN201410728564 A CN 201410728564A CN 104360463 B CN104360463 B CN 104360463B
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Abstract
The three telecentricity coaxial-illuminating imaging optical systems of the present invention, its pre-objective group and rearmounted objective lens constitute doubly telecentric imaging optical system, and pre-objective group, Amici prism and illumination objective lens group constitute doubly telecentric coaxial-illuminating optical system；Aperture diaphragm AS1It is positioned on the image space focal plane of pre-objective group and on the focal plane, thing side of rearmounted objective lens, aperture diaphragm AS2It is positioned on the image space focal plane of pre-objective group and on the focal plane, thing side of illumination objective lens group.It is three telecentric systems that two doubly telecentric systems are coupled to form by the present invention, has coaxial-illuminating and imaging dual function.Imaging system visual field reaches 180mm, and image deformation is less than 0.1%；Full filed resolution reaches 200lp/mm, and image quality is uniform, illuminator can realize the homogenization illumination of whole visual field, it is to avoid the defect of the illumination unevenness that coaxial annular optical illumination produces.
Description
Technical field
The invention belongs to optical image technology, be especially applicable to the optical system of the Machine Vision Detection of big visual field, high-resolution, low distortion, specifically three telecentricity coaxial-illuminating imaging optical systems.
Background technology
Replacing human eye to carry out photoelectricity automatic on-line detection in high precision, at high speed by machine vision is that one of topmost direction is developed in industry on-line checking field in recent ten years.Focus or zoom lens carries out that formation method is simple, low cost with traditional, but have lower column defects: 1, pattern distortion is relatively big, can have a strong impact on certainty of measurement particularly with distortion big during big view field imaging；2, the image objects having certain depth easily can be obscured the side projection imaging of object with the image needing detection faces, reduce certainty of measurement；3, commonly focus or zoom lens out of focus imaging can cause bigger measurement error.
Telecentric beam path can overcome disadvantage mentioned above, is highly suitable for the application of machine vision automatic on-line detection field, thus use to telecentric optical system in recent years gets more and more.
Telecentric beam path is divided into thing side's telecentric beam path and telecentric beam path in image space, and aperture diaphragm is respectively placed in image space focal plane and focal plane, thing side by its principle exactly so that the chief ray of thing side and image space is parallel to optical axis.Being combined by both telecentric beam paths and just constitute doubly telecentric imaging optical path, i.e. middle aperture diaphragm position is the image space focal plane of front objective lens, is also the focal plane, thing side of rear objective lens.So chief ray of image side is parallel to optical axis, the advantage of thing side's telecentricity and telecentric beam path in image space is combined, and the distortion of thing side and image space distortion all eliminate so that accuracy of detection improves further.Telecentric beam path illumination exceptionally illumination and coaxial intraoral illumination two ways.Outer illumination realizes relatively simple, but illumination unevenness phenomenon easily occurs, especially true for big field illumination.Coaxial intraoral illumination, due to part light path to be utilized, designs complex, and cost is high, and brightness is lower slightly, but uniformity is fine, is requiring that higher detection occasion needs to use intraoral illumination.
Proposing a kind of symmetrical expression double-telecentric projection optical system in Chinese patent 200710038508.0, its advantage is that resolution has reached 700lp/mm when enlargement ratio is for-1, it is adaptable to field of lithography application in high precision.Shortcoming is that whole system employs 18 eyeglasses, and resetting difficulty is relatively big, and have employed the special glasss such as price SFPL51Y costly, relatively costly.Visual field is 31.446mm, operating distance 29mm, is not suitable for big visual field detection occasion.
Proposing a kind of coaxial double-telecentric imaging optics system in Chinese patent 201010242686.7, its advantage is to use less eyeglass to realize high magnification doubly telecentric imaging, and distortion is less than 0.1%；Illuminator falls to penetrating coaxial Kohler illumination in using, and uniformity is preferable；Kohler illumination field stop is variable, can control illumination field of view size.Shortcoming is that visual field only has 19.2mm, is not suitable for the detection of big visual field part；Kohler illumination structure is more complicated, debugs difficulty.
In United States Patent (USP) US5715050, it is proposed that a kind of coaxial-illuminating doubly telecentric optical measuring system.The advantage of this system is that image face site error is low on certainty of measurement impact, but the enlargement ratio of this system is low, lighting area size can not control, therefore can not obtain high certainty of measurement and it also needs to the contrast images that extra optical system has ensured after doubly telecentric imaging system, add design cost and dress school difficulty.
Summary of the invention
Present invention aim to overcome that the defect of prior art, there is provided three telecentricity coaxial-illuminating imaging optical systems of the Machine Vision Detection of a kind of big visual field, low range, high-resolution, coaxial intraoral illumination, it is achieved the testee within a diameter of 180mm is carried out high accuracy imaging and detection.
The technical scheme that the present invention realizes above-mentioned purpose is as follows: three telecentricity coaxial-illuminating imaging optical systems, the doubly telecentric imaging optical path formed including aperture diaphragm is positioned over image space focal plane and focal plane, thing side, it is characterised in that: include pre-objective group G1, Amici prism BS, rearmounted objective lens G2With illumination objective lens group G3, pre-objective group G1With rearmounted objective lens G2Constitute doubly telecentric imaging optical system, pre-objective group G1, Amici prism BS and illumination objective lens group G3Constitute doubly telecentric coaxial-illuminating optical system；
Aperture diaphragm AS1It is positioned at pre-objective group G1Image space focal plane on and rearmounted objective lens G2Focal plane, thing side on so that front objective lens G1With rear objective lens G2Constitute doubly telecentric imaging optical path.Aperture diaphragm AS2It is positioned at pre-objective group G1Image space focal plane on and illumination objective lens group G3Focal plane, thing side on so that front objective lens G1With illumination objective lens group G3Constitute doubly telecentric illumination path.
Described pre-objective group G1, before object plane to Amici prism BS, set gradually a positive biconvex lens L1, a diverging meniscus lens L2, a positive meniscus lens L3, a diverging meniscus lens L4With a diverging meniscus lens L5, wherein positive meniscus lens L3With diverging meniscus lens L4Form the double glued group of positive bent moon.
Described Amici prism BS is that the double gluing of two corner cube prisms forms, and reflection and transmission ratio for 1:1, is used for that send from lighting source, by illumination objective lens group G3Luminous reflectance enter pre-objective group G1, thus realize the big visual field Uniform Illumination to object plane；The light reflected from testee is through pre-objective group G1Rearmounted objective lens G is entered afterwards by Amici prism2Arrive CCD target surface imaging.
Described rearmounted objective lens G2It is made up of 6 lens, from Amici prism BS to CCD target surface, sets gradually and become as aperture diaphragm AS1, a diverging meniscus lens L6, a diverging meniscus lens L7, a positive meniscus lens L8, a positive biconvex lens L9, a diverging meniscus lens L10With a positive meniscus lens L11, wherein positive biconvex lens L9With diverging meniscus lens L10Form the most double glued group.
Described illumination objective lens group G3It is made up of 3 lens, from aperture diaphragm AS2Start to set gradually along optical axis to include a positive biconvex lens L12, a diverging meniscus lens L13With a positive planoconvex lens L14, wherein positive biconvex lens L12With diverging meniscus lens L13Form the most double glued group.
Described doubly telecentric imaging system is 1 with the use of target surface ", pixel be 4.5 μ m 4.5 μm area array CCD cameras.
The LED area light source that lighting source is diameter 7mm of described doubly telecentric illumination imaging systems, full filed illumination uniformity is within 10%.
Doubly telecentric imaging optical system in the present invention, its object distance is 288.2mm, and true field is 175mm；Image distance is 23.58mm, and image space is 16mm, enlargement ratio is 0.0914 ×；Full filed image space imaging resolution reaches 200lp/mm, and distortion is less than 0.1%.
It is three telecentric systems that two doubly telecentric systems are coupled to form by the present invention, has coaxial-illuminating and imaging dual function.Doubly telecentric illuminator is coupled with doubly telecentric imaging system by Amici prism BS, pre-objective group G1It is doubly telecentric imaging optical path and the common portion of doubly telecentric coaxial-illuminating light path, plays the dual function of illumination and imaging.
From the point of view of imaging optical path, system visual field reaches 180mm, belongs to big visual field in doubly telecentric system；Image deformation is less than-0.1%；Full filed resolution reaches 200lp/mm, and image quality is uniform.From the point of view of illumination path, use in doubly telecentric to fall to penetrating coaxial-illuminating and can realize the homogenization illumination of whole visual field, it is to avoid the defect of the illumination unevenness that coaxial annular optical illumination produces.
Accompanying drawing explanation
Fig. 1: the present invention three telecentricity coaxial-illuminating imaging optical system structure chart；
Fig. 2: pre-objective group structure chart；
The aberration curve figure of Fig. 3: pre-objective group；
Fig. 4: rearmounted objective lens structure chart；
The aberration curve figure of Fig. 5: rearmounted objective lens；
Fig. 6: doubly telecentric imaging system structure chart；
The aberration curve figure of Fig. 7: doubly telecentric imaging system；
The MTF curve figure of Fig. 8: doubly telecentric imaging system；
Fig. 9: illumination objective lens group structure chart；
Figure 10: doubly telecentric lighting system structure figure；
Figure 11: doubly telecentric illuminator lighting quality analysis chart.
Detailed description of the invention
First according to true field D=175mm, resolution requirement is the requirement of 0.05mm, determine Phase Receiver device use 1 " CCD camera, pixel dimension is 4.5 μ m 4.5 μm, thus calculate enlargement ratio be β=16/175=0.0914 ×.Then according to enlargement ratio requirement, pre-objective group G is determined1Focal length is f'1=45.5mm, rearmounted objective lens G2Focal length is f'2=497mm.Respectively to pre-objective group G1With rearmounted objective lens G2Carry out optical design, pre-objective group G respectively1Aperture diaphragm AS is placed at rear focus1, with rearmounted objective lens G2Object focus overlaps, and constitutes doubly telecentric light path.
Pre-objective group G1Employing reverse optical path designs, as shown in Figure 2.Aperture diaphragm AS from left to right it is followed successively by along optical axis1, diverging meniscus lens L5, diverging meniscus lens L4, positive meniscus lens L3, diverging meniscus lens L2, positive biconvex lens L1, wherein positive meniscus lens L3With diverging meniscus lens L4The double glued group of composition.The incident parallel light angle of visual field is 2 ω=20 °, and emergent ray chief ray is parallel to optical axis.Design through aberration optimization, pre-objective group G as seen from Figure 31Spherical aberration in image planes, astigmatism, the curvature of field are within 0.5mm, and distortion is less than-0.2%.
Rearmounted objective lens G2Using forward light path design, structure chart is as shown in Figure 4.Aperture diaphragm AS from left to right it is followed successively by along optical axis1, diverging meniscus lens L6, diverging meniscus lens L7, positive meniscus lens L8, positive biconvex lens L9, diverging meniscus lens L10With positive meniscus lens L11, wherein positive biconvex lens L9With diverging meniscus lens L10Form the most double glued group.Aperture diaphragm AS1Being positioned at thing side's focal plane, the incident parallel light angle of visual field is 2 ω=20 °, and the chief ray of emergent ray is parallel to optical axis.Design through aberration optimization, the most rearmounted objective lens G2Spherical aberration in image planes, astigmatism, the curvature of field are within 0.1mm, and distortion is less than-0.2%.
By pre-objective group G1Camera lens overturns, with rearmounted objective lens G2At aperture diaphragm AS1Place docks mutually, doubly telecentric imaging system shown in composition diagram 6.This system is afocal system, and incident illumination chief ray is parallel to optical axis, and emergent light chief ray, also parallel with optical axis, constitutes double telecentric structure.From the Aberration Analysis curve of Fig. 7, spherical aberration, astigmatism, the curvature of field are all within 0.1mm；Due to front objective lens G1With rear objective lens G2Distortion contrary sign is equal, so resultant distortion is less than-0.1%, less than common thing side telecentricity and the distortion of telecentric structure.From the MTF curve of Fig. 8, full filed resolution reaches 200lp/mm, as long as the corresponding resolution as receiving device is less than 10 μm higher than 100lp/mm, i.e. pixel dimension, native system can be coordinated to use.
Illumination objective lens group G3Method for designing and rearmounted objective lens G2Design is similar, but owing to illuminator is less demanding to aberration, and in view of cost factor, only with three lens, structure is as shown in Figure 9.Aperture diaphragm AS from left to right it is followed successively by along optical axis2, positive biconvex lens L12, diverging meniscus lens L13With positive planoconvex lens L14, wherein positive biconvex lens L12With diverging meniscus lens L13Form the most double glued group.Illumination objective lens group G3With pre-objective group G1Dock mutually at aperture diaphragm, doubly telecentric line illumination systems shown in composition Figure 10.This system is parallel to optical axis from the chief ray of illumination surface light source face emergent ray, and the chief ray of emergent ray, also parallel with optical axis, constitutes double telecentric structure.Figure 11 is the Luminance Analysis figure of illuminated object plane.Full filed brightness of illumination all ratios are more uniform as can be seen from Figure, and in X-axis and Y-axis, illumination uniformity is substantially within 10%, therefore can provide Uniform Illumination to whole object plane.
By pre-objective group G shown in Fig. 21Camera lens overturns, rearmounted objective lens G with shown in Fig. 22At aperture diaphragm AS1Place docks mutually, doubly telecentric imaging system shown in composition diagram 6.By pre-objective group G shown in Fig. 21Camera lens overturns, by illumination objective lens group G shown in Fig. 93AS at aperture diaphragm2Dock mutually, doubly telecentric line illumination systems shown in composition Figure 10.Finally by doubly telecentric imaging system shown in Fig. 6, with doubly telecentric line illumination systems shown in Figure 10, combined by Amici prism BS, become the three telecentricity coaxial-illuminating imaging optical systems of the present invention shown in Fig. 1.
Claims (6)
1. three telecentricity coaxial-illuminating imaging optical system, the doubly telecentric imaging optical path formed including aperture diaphragm being positioned over image space focal plane and focal plane, thing side, it is characterised in that: include pre-objective group G1, Amici prism BS, rearmounted objective lens G2With illumination objective lens group G3, pre-objective group G1With rearmounted objective lens G2Constitute doubly telecentric imaging optical system, pre-objective group G1, Amici prism BS and illumination objective lens group G3Constitute doubly telecentric coaxial-illuminating optical system；
Aperture diaphragm AS1It is positioned at pre-objective group G1Image space focal plane on and rearmounted objective lens G2Focal plane, thing side on, aperture diaphragm AS2It is positioned at pre-objective group G1Image space focal plane on and illumination objective lens group G3Focal plane, thing side on；
Described pre-objective group G1, before object plane to Amici prism BS, set gradually a positive biconvex lens L1, a diverging meniscus lens L2, a positive meniscus lens L3, a diverging meniscus lens L4With a diverging meniscus lens L5, wherein positive meniscus lens L3With diverging meniscus lens L4Form the double glued group of positive bent moon.
Three telecentricity coaxial-illuminating imaging optical systems the most according to claim 1, it is characterised in that: described Amici prism BS is that the double gluing of two corner cube prisms forms, and reflection and transmission ratio for 1:1, is used for that send from lighting source, by illumination objective lens group G3Luminous reflectance enter pre-objective group G1, thus realize the big visual field Uniform Illumination to object plane；The light reflected from testee is through pre-objective group G1Rearmounted objective lens G is entered afterwards by Amici prism BS2Arrive CCD target surface imaging.
Three telecentricity coaxial-illuminating imaging optical systems the most according to claim 1, it is characterised in that: described rearmounted objective lens G2, from Amici prism BS to CCD target surface, set gradually and become as aperture diaphragm AS1, a diverging meniscus lens L6, a diverging meniscus lens L7, a positive meniscus lens L8, a positive biconvex lens L9, a diverging meniscus lens L10With a positive meniscus lens L11, wherein positive biconvex lens L9With diverging meniscus lens L10Form the most double glued group.
Three telecentricity coaxial-illuminating imaging optical systems the most according to claim 1, it is characterised in that: described illumination objective lens group G3, from aperture diaphragm AS2Start to set gradually along optical axis to include a positive biconvex lens L12, a diverging meniscus lens L13With a positive planoconvex lens L14, wherein positive biconvex lens L12With diverging meniscus lens L13Form the most double glued group.
Three telecentricity coaxial-illuminating imaging optical systems the most according to claim 1, it is characterised in that: described doubly telecentric imaging system is 1 with the use of target surface ", pixel be 4.5 μ m 4.5 μm area array CCD cameras.
Three telecentricity coaxial-illuminating imaging optical systems the most according to claim 1, it is characterised in that: the LED area light source that lighting source is diameter 7mm of described doubly telecentric line illumination systems, full filed illumination uniformity is within 10%.
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| CN105467809A (en) * | 2015-12-15 | 2016-04-06 | 重庆触视科技有限公司 | Distortion-proof 3D holographic projection apparatus |
| CN107193115A (en) * | 2017-07-25 | 2017-09-22 | 埃卫达智能电子科技（苏州）有限公司 | A kind of image bilateral telecentric optical system of near ultraviolet band |
| CN109425969B (en) * | 2017-08-28 | 2021-10-01 | 宁波舜宇车载光学技术有限公司 | Optical lens |
| CN107894651A (en) * | 2017-12-18 | 2018-04-10 | 苏州灵猴机器人有限公司 | Machine Vision Detection camera lens |
| CN110381230A (en) * | 2018-04-13 | 2019-10-25 | 甘肃智呈网络科技有限公司 | A kind of binocular camera shooting device of preposition beam-splitting structure |
| CN109307927B (en) * | 2018-11-16 | 2024-02-20 | 珠海博明软件有限公司 | Built-in coaxial illumination's two telecentric lens of two visual fields |
| CN109541802B (en) * | 2019-01-21 | 2021-03-16 | 上海理工大学 | Double-optical-path double-telecentric optical system |
| CN109991724B (en) * | 2019-04-16 | 2023-11-28 | 佛山科学技术学院 | Double telecentric fixed-focus optical system |
| CN112985777A (en) * | 2021-02-26 | 2021-06-18 | 中国兵器工业集团第二一四研究所苏州研发中心 | Modulation transfer function test system and test method of EMCCD assembly |
| CN113589468B (en) * | 2021-07-29 | 2023-06-06 | 江西晶浩光学有限公司 | Optical system, camera module and electronic equipment |
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| JP3366746B2 (en) * | 1994-10-20 | 2003-01-14 | 株式会社モリテックス | Video scope camera head |
| JP3386269B2 (en) * | 1995-01-25 | 2003-03-17 | 株式会社ニュークリエイション | Optical inspection equipment |
| US6198577B1 (en) * | 1998-03-10 | 2001-03-06 | Glaxo Wellcome, Inc. | Doubly telecentric lens and imaging system for multiwell plates |
| JP3708845B2 (en) * | 2001-06-19 | 2005-10-19 | 株式会社ミツトヨ | Both telecentric objective lenses |
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| CN100456074C (en) * | 2007-03-27 | 2009-01-28 | 上海微电子装备有限公司 | Symmetrical double-telecentric projection optical system |
| CN102346291B (en) * | 2010-08-02 | 2013-09-11 | 上海微电子装备有限公司 | Coaxial double-telecentric imaging optics system |
| CN103076677A (en) * | 2013-02-01 | 2013-05-01 | 桂林电子科技大学 | Double-telecentric Kohler illumination light path |
| CN203365787U (en) * | 2013-06-28 | 2013-12-25 | 中国科学院西安光学精密机械研究所 | Two-gear zoom optical system |
| CN203799100U (en) * | 2014-03-25 | 2014-08-27 | 维嘉数控科技（苏州）有限公司 | Double telecentric lens |
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Effective date of registration: 20181107 Address after: 541000 Guilin Qixing District High-tech Zone Information Industry Park D-12 Information Incubation Building A Third Floor C309, C310 Office Patentee after: Guangxi Vision Technology Co., Ltd. Address before: 541004 1 Guilin, the Guangxi Zhuang Autonomous Region Patentee before: Guilin University of Electronic Technology |