Non-Destructive Identification of Weld-Boundary and Porosity Formation During Laser Transmission Welding by Using Optical Coherence Tomography

Kim, Kanghae; Kim, Pilun; Lee, Jaeyul; Kim, Suwon; Park, Sungjo; Choi, Soo Ho; Hwang, Junho; Lee, Jong Hoon; Lee, Ho; Wijesinghe, Ruchire Eranga; Jeon, Mansik; Kim, Jeehyun

doi:10.1109/access.2018.2882527

Cited by 24 publications

(9 citation statements)

References 23 publications

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“…Although related assessments were not descriptively studied, vision inspection based quantifications of previously reported defect inspection studies were well considered for baseline comparisons [36,37]. In previous studies [21,35,[38][39][40][41], non-destructive identification of industrial materials has been achieved for diverse industrial materials. However, to date, a VLSC-synchronized with dual SD-OCT multimodal image inspection system for examining OTF sample defects in real time has not been studied in detail.…”

Section: Discussionmentioning

confidence: 99%

Vision-Inspection-Synchronized Dual Optical Coherence Tomography for High-Resolution Real-Time Multidimensional Defect Tracking in Optical Thin Film Industry

et al. 2020

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Large-scale product inspection is an important aspect in thin film industry to identify defects with a high precision. Although vision line scan camera (VLSC)-based inspection has been frequently implemented, it is limited to surface inspections. Therefore, to overcome the conventional drawbacks, there is a need to extend inspection capabilities to internal structures. Considering that VLSC systems have access to rich information, such as color and texture, high-resolution real-time multimodal optical synchronization between VLSC and dual spectral domain optical coherence tomography (SD-OCT) systems was developed with a laboratory customized in-built automated defect-tracking algorithm for optical thin films (OTFs). Distinguishable differences in the color and texture of the bezel area were precisely determined by the VLSC. Detailed OCT assessments were conducted to verify the detection of previously unobtainable border regions and micrometer-range sub-surface defects. To enhance the accuracy of the method, VLSC images were aided for the precise surface defect identification using OCT and the image acquisition, signal processing, image analysis, and classification of both techniques were simultaneously processed in real-time for industrial applicability. The results demonstrate that the proposed method is capable of detecting and enumerating total number of defects in OTF samples with exceptional resolution and in a cost-effective manner facilitating wide area inspection for OTF samples.

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Section: Discussionmentioning

confidence: 99%

Vision-Inspection-Synchronized Dual Optical Coherence Tomography for High-Resolution Real-Time Multidimensional Defect Tracking in Optical Thin Film Industry

et al. 2020

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“…OCT is a non-invasive optical imaging technique used to obtain high-resolution, cross-sectional images of inner microstructures in materials and biological tissues [ 9 ]. OCT has been widely applied in various fields, including medical diagnosis [ 10 , 11 ], dentistry [ 12 , 13 ], and industrial applications [ 14 , 15 ]. The single-scanner-based unidirectional scanning of conventional OCT has been applied in numerous applications [ 16 , 17 ].…”

Section: Introductionmentioning

confidence: 99%

Integrated Quad-Scanner Strategy-Based Optical Coherence Tomography for the Whole-Directional Volumetric Imaging of a Sample

Saleah

Seong

Han

et al. 2021

Sensors

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Whole-directional scanning methodology is required to observe distinctive features of an entire physical structure with a three dimensional (3D) visualization. However, the implementation of whole-directional scanning is challenging for conventional optical coherence tomography (OCT), which scans a limited portion of the sample by utilizing unidirectional and bidirectional scanning methods. Therefore, in this paper an integrated quad-scanner (QS) strategy-based OCT method was implemented to obtain the whole-directional volumetry of a sample by employing four scanning arms installed around the sample. The simultaneous and sequential image acquisition capabilities are the conceptual key points of the proposed QS-OCT method, and were implemented using four precisely aligned scanning arms and applied in a complementary way according to the experimental criteria. To assess the feasibility of obtaining whole-directional morphological structures, a roll of Scotch tape, an ex vivo mouse heart, and kidney specimens were imaged and independently obtained tissue images at different directions were delicately merged to compose the 3D volume data set. The results revealed the potential merits of QS-OCT-based whole-directional imaging, which can be a favorable inspection method for various discoveries that require the dynamic coordinates of the whole physical structure.

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“…SS-OCT has deeper penetration and faster image acquisition time compared with other OCT systems and the light source of this system is divided into a spectrum through a tunable laser instead of a super-luminescent diode [28]. OCT has been widely applied in medical diagnosis [29][30][31][32][33][34], entomological studies [35,36], industrial applications [37][38][39], and in the agricultural field [40,41]. Nowadays, with developments being made in terms of the size of systems and types of light sources, OCT could be used for the advanced diagnosis of tooth decay and periodontal disease [42].…”

Section: Introductionmentioning

confidence: 99%

Assessment of the Inner Surface Roughness of 3D Printed Dental Crowns via Optical Coherence Tomography Using a Roughness Quantification Algorithm

et al. 2020

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Dental crowns are used to restore decayed or chipped teeth, where their surfaces play a key role in this restoration process, as they affect the fitting and stable bonding of the prostheses. The surface texture of crowns can interfere with this restoration process, therefore the measurement of their inner surface roughness is very important but difficult to achieve using conventional imaging methods. In this study, the inner surfaces of dental crowns were three-dimensionally (3D) visualized using swept-source optical coherence tomography (SS-OCT) system. Nine crowns were fabricated with a commercial 3D printer using three different hatching methods (one-way, cross, and 30° angle counterclockwise) and three different build direction angles (0°, 45°, and 90°). In addition, an image processing algorithm was developed, which uses morphological filtering, boundary detection, and a high-pass frequency filtering technique, to quantitatively evaluate the inner surface roughness of the dental crowns cross-sections with the depth-of-focus set to match two different regions. The averaged smoothness of fabricated crown was effectively produced using the cross-hatching and the build direction angle of 90° by the respective process. Thus, the results confirm the potential use of this methodology to determine the best parameters to use in 3D fabrication for improving the effectiveness and stability of dental prostheses. INDEX TERMS 3D printing, dental crown, image processing, optical coherence tomography, surface roughness.

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Non-Destructive Identification of Weld-Boundary and Porosity Formation During Laser Transmission Welding by Using Optical Coherence Tomography

Cited by 24 publications

References 23 publications

Vision-Inspection-Synchronized Dual Optical Coherence Tomography for High-Resolution Real-Time Multidimensional Defect Tracking in Optical Thin Film Industry

Vision-Inspection-Synchronized Dual Optical Coherence Tomography for High-Resolution Real-Time Multidimensional Defect Tracking in Optical Thin Film Industry

Integrated Quad-Scanner Strategy-Based Optical Coherence Tomography for the Whole-Directional Volumetric Imaging of a Sample

Assessment of the Inner Surface Roughness of 3D Printed Dental Crowns via Optical Coherence Tomography Using a Roughness Quantification Algorithm

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