Automatic scratch detector for optical surface

Zhang, Hongyan; Wang, Zi-Hao; Fu, Haiyan

doi:10.1364/oe.27.020910

Cited by 15 publications

(3 citation statements)

References 17 publications

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“…Cap defect detection results: Existing image segmentation methods are mainly divided into the following categories: threshold-based, edge-based [ 24 , 25 ] and methods based on specific theories. Since the captured image usually contains spot-like Gaussian noises and may have uneven surfaces and inhomogeneous illuminations, the contrast between the defects and the background information is usually not that high.…”

Section: Methodsmentioning

confidence: 99%

A Very Fast Image Stitching Algorithm for PET Bottle Caps

et al. 2022

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In the beverage, food and drug industry, more and more machine vision systems are being used for the defect detection of Polyethylene Terephthalate (PET) bottle caps. In this paper, in order to address the result of cylindrical distortions that influence the subsequent defect detection in the imaging process, a very fast image stitching algorithm is proposed to generate a panorama planar image of the surface of PET bottle caps. Firstly, the three-dimensional model of the bottle cap is established. Secondly, the relative poses among the four cameras and the bottle cap in the three-dimensional space are calculated to obtain the mapping relationship between three-dimensional points on the side surface of the bottle cap and image pixels taken by the camera. Finally, the side images of the bottle cap are unfolded and stitched to generate a planar image. The experimental results demonstrate that the proposed algorithm unfolds the side images of the bottle cap correctly and very fast. The average unfolding and stitching time for 1.6-megapixel color caps image can reach almost 123.6 ms.

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Section: Methodsmentioning

confidence: 99%

A Very Fast Image Stitching Algorithm for PET Bottle Caps

et al. 2022

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“…At present, plenty of qualitative defect detection methods have been developed, among which the human visual inspection method [1] is widely applied. However, this method has low efficiency and accuracy because it depends greatly on the operator's experience [2]. To solve these problems, the machine vision technique is developed using different image processing algorithms.…”

Section: Introductionmentioning

confidence: 99%

Fast Measurement of Surface Topographies Using a Phase-Measuring Deflectometric Microscopy

Zhang

Lang

et al. 2023

IEEE Photonics J.

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With the fast development in the fields of photovoltaics and integrated circuits, the measurement of surface topographies and micro-scaled defects has attracted intensive interests. However, existing measurement methods are timeconsuming and unsuitable for in-situ detection. Therefore, a fast topographic measurement method is developed based on the deflectometric microscope system. Microscopic deflectometry is an attractive tool due to its high sensibility to surface slopes and large dynamic range of measurement. For the quantitative reconstruction of surface topographies from slopes, an integration method is developed based on the minimum spanning tree, and the integration path is designed based on a sparse representation and a curl map. The robustness and accuracy of the integration method are validated by numerical simulation and experiments. This method can achieve a high measurement accuracy with a high lateral resolution and a depth of field of 90 μm, hereby improving the manufacturing efficiency and quality of opto-electronics functional devices.

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“…One showed an inventory of an optical pickup unit for light reflection into the charge coupled device (CCD) with polarizers and Infrared-(IR) cut filters for intensification of the laser beam [6]. However, for better resolution, machine vision inspection methods using various algorithms to examine the 2D surface images have also been studied but they can only be measured in static state [7]. In addition, it is still a vast cost of investment for industry.…”

Section: Introductionmentioning

confidence: 99%

Utilization of CD and DVD Pick-Up Heads for Scratch Inspection of Magnetic Disk in Dynamic State Using Microcontroller

Polsawat

Tipcharoen²,

Siritaratiwat

2020

Applied Sciences

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A non-destructive technique to inspect a scratch on all magnetic disks in the beginning process of hard disk drive (HDD) manufacturing by using CD and DVD pick-up heads as the detector is proposed. It requires a 100% disk inspection of micrometer-sized scratches in a quick measurement with low cost inventing. Most of the previous studies were in static state but this is the first time to be done in dynamic study using the microcontroller in order to promptly serve for industrial utilization. The size, position, and shape characteristic of scratches are examined using light reflection technique. The results show that, when the laser beam is targeted on a magnetic disk in a position, either scratch or non-scratch, the reflected light intensity differs. The DVD pick-up head can detect the width and the surface characteristic of the scratches, which is similar to the results from scanning electron microscope (SEM) for all scratches sizes less than 100 µm. It is also found that using a DVD pick-up head provides a better resolution of shape characteristic and roughness of scratches surface than a CD pick-up head. Hence, the scratch size of 10s µm scale on the magnetic disk can be accurately characterized by this proposed technique, which can be further utilized for magnetic disk inspection in the hard disk drive manufacturing process.

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Automatic scratch detector for optical surface

Cited by 15 publications

References 17 publications

A Very Fast Image Stitching Algorithm for PET Bottle Caps

A Very Fast Image Stitching Algorithm for PET Bottle Caps

Fast Measurement of Surface Topographies Using a Phase-Measuring Deflectometric Microscopy

Utilization of CD and DVD Pick-Up Heads for Scratch Inspection of Magnetic Disk in Dynamic State Using Microcontroller

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