Surface Characterization and Defect Detection by Analysis of Images Obtained with Coherent Light

Lonardo, P.M.; Bruzzone, Agostino; Gambaro, Carla; Parizzi, F.

doi:10.1016/s0007-8506(07)62049-6

Cited by 28 publications

(6 citation statements)

References 7 publications

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“…For the surface defect detection, an optical method referred to as the laser scattering method has often been employed [8,9]. In the method, surface defect detection is carried out by detecting light scattering patterns generated by the irradiation of a laser beam on an area of surface having a single or multiple surface defects.…”

Section: Introductionmentioning

confidence: 99%

Design and Testing of a Micro-thermal Sensor Probe for Nondestructive Detection of Defects on a Flat Surface

et al. 2018

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This paper presents a design and testing of a micro-thermal sensor probe for realizing the proposed concept of non-contact surface defect detection, in which a change in heat flow across the gap between the tip of the micro-thermal sensor probe and a target surface is utilized to recognize the existences of surface defects. In the proposed concept of surface defect detection, the probe tip, where the micro-thermal sensor is embedded, is required to be placed as close as possible to the target surface for highly sensitive surface defect detection. For the purpose, an optical tilt detection assembly based on the laser autocollimation is designed to detect relative tilt of the micro-thermal sensor with respect to a target surface. A sensor probe assembly, in which the fabricated micro-thermal sensor is embedded to the tip of a hollow-shaped piezoelectric actuator by using a homemade sensor mount, is also designed in such a way that the sensor element will face to a target surface. A prototype micro-thermal sensor probe is constructed by integrating the optical tilt detection assembly and the sensor probe assembly, and some experiments have been carried out to verify the basic performances of the prototype micro-thermal sensor probe.

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Section: Introductionmentioning

confidence: 99%

Design and Testing of a Micro-thermal Sensor Probe for Nondestructive Detection of Defects on a Flat Surface

et al. 2018

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“…Surface inspection is one of the key technologies for reduction of defects on such a smoothly-finished surface. For defect inspection, laser scattering methods have often been used (Lonardo, et al, 1991, Takami, 1997, Takahashi, et al, 2011. In the methods, defects can be detected by capturing scattered lights from defects on a smoothly-finished surface by using highly-sensitive photodetectors.…”

Section: Introductionmentioning

confidence: 99%

Design of fabrication process of a thermal contact sensor for surface defect inspection

Shimizu

Ohba

Gao

2014

JAMDSM

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A fabrication process of a contact detection sensor, which is thermally-sensitive thin film sensor referred to as a thermal contact sensor to be used for a surface defect inspection, is designed based on photolithography process. The existence of a small defect, the size of which is on the order of several-ten nanometers, would be detected by capturing frictional heat generated at the contact between the thermal contact sensor and the defect. The thermal contact sensor is therefore designed to detect small quantity of frictional heat, the rate of heat supply of which is estimated to be on the order of microwatts. In this paper, followed by the fabrication of the first prototype thermal contact sensor in the previous study, the structure of the thermal contact sensor is modified to make the thermally-sensitive area of the thermal contact sensor to be located at its top surface. For further stable fabrication of a thermal contact sensor, lift-off process with a positive resist is also introduced in the sensor fabrication process. Experiments are carried out to verify the feasibility of the fabricated second prototype thermal contact sensor. In addition, aiming to improve sensitivity of the thermal contact sensor, the relationship between the sensor sensitivity and the sensor bias voltage is investigated in experiments. Furthermore, FEM simulation is carried out to estimate the increase of the sensor temperature due to a self-heating effect by the bias voltage applied to the thermal contact sensor, since the sensor temperature deviation could affect the sensitivity of the thermal contact sensor.

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“…Different architectures fall into this category ranging from the most obvious that simply determine the presence of defects by detecting reflected optical energy in directions other than those of the specular reflection 8,9 to other, more elaborate ones, whose output resembles the angular spectrum of the reflected wavefront and can be correlated with some roughness parameters of interest or defect features. [10][11][12] 2. Some systems render the surface spectrum by free space propagation.…”

Section: Introductionmentioning

confidence: 99%

Episcopic coaxial illumination instrument for the simultaneous recording of the speckle signature in the energy spectrum and in the image of scattering reflective surfaces

et al. 2013

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Abstract. The inspection of optically rough surfaces searching for defects or other macroscopic features, or with the aim of characterizing roughness, are tasks well suited to optical techniques. We present the concept, the architecture, the mathematical modeling, the calibration, and some results of a device with episcopic coaxial illumination, specifically developed for surface inspections, which simultaneously renders both a coherent image and the energy spectrum of the complex reflection coefficient of a portion of the surface, precisely delimited by the illuminating laser spot. This concept is based on the well-known, singlelens, coherent image processing setup with beamsplitters added to insert the illuminating beam and to allow simultaneous access to the Fourier transform plane and to the image plane. Information about the resolved macroscopic features and the nonresolved surface microstructure (through the corresponding speckle signature) is obtained in both planes which enables different surface analysis strategies. The speckle sizes in the spectrum, and in the image, can be controlled by selecting the size of the illuminated area of the object and the lens aperture, respectively. Some envisaged applications are the detection and characterization of defects or macroscopic structures in rough surfaces, identification of authentication marks, evaluation of roughness parameters, and of speckle statistics.

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Surface Characterization and Defect Detection by Analysis of Images Obtained with Coherent Light

Cited by 28 publications

References 7 publications

Design and Testing of a Micro-thermal Sensor Probe for Nondestructive Detection of Defects on a Flat Surface

Design and Testing of a Micro-thermal Sensor Probe for Nondestructive Detection of Defects on a Flat Surface

Design of fabrication process of a thermal contact sensor for surface defect inspection

Episcopic coaxial illumination instrument for the simultaneous recording of the speckle signature in the energy spectrum and in the image of scattering reflective surfaces

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