New presentation of Papers at Sensofar Metrology
New presentation of Papers at Sensofar Metrology
Sensofar R&D is constantly growing its know-how, technology and system capabilities. These developments are illustrated by Sensofar’s continued activity within and for the scientific metrology community.
Two papers will be presented during this month of June, that clearly demonstrate this involvement:
SPIE Optical Metrology
Wed 23 June, 9:20am, 3D Microscopy Session, Paper 11782-24
Technical Event: Optical Measurement Systems for Industrial Inspection XII
‘ Metrological characterization of different methods for recovering the optically sectioned image by means of structured light ‘
Presenter: Pol Martínez, MSc (R&D)
Abstract. Imaging confocal microscopy (ICM) and focus variation (FV) are two of the most used technologies for 3D surface metrology. Both methods rely on the depth of focus of the microscope objective, which depends on its numerical aperture and wavelength of the light source to compute an optical section.
In this paper we study how several methods of structured illumination microscopy affect the metrological characteristics of an areal optical profiler. We study the effect of the projection of different structured patterns, the sectioning algorithms, and the use of high and low frequency components onto the optically sectioned image. We characterized their performance in terms of system noise, instrument transfer function and metrological characteristics such as roughness parameters and step height values.
Full abstracts as well as exact locations and final program of the presentations can be found at SPIE Optical Metrology technical conferences .
EUSPEN’s Virtual International Conference
Tue 8 June, 17h. to 18h. ICE21206 – P5.07 – Poster Room 4: Metrology (High repetition rate 3D optical sensor)
‘Study on linear stages for a 3D optical sensor’
Presenter: Pol Martínez, MSc (R&D)
Abstract. Surface characterization provides crucial indicators in many quality control processes, as surface parameters give information about the properties of the item inspected. The most used technologies for surface characterization in the micro- and nano level are Coherence Scanning Interferometry (CSI), Imaging Confocal Microscopy (ICM) and Focus Variation (FV). These technologies are based on optical principles, causing no damage to the sample while being inspected and obtaining nanometer resolution. Nevertheless, they suffer from having to perform a mechanical scan of the whole sensor, causing the acquisition time to be increased.
To evolve towards industry 4.0, closed loop manufacturing is essential to reach the automatization of the different steps of the manufacturing processes. In this context, industry is demanding higher speeds and smaller sensors to reduce the quality inspection costs, especially in in-line processes where it is usually required to inspect the sample in less than 1 s. To achieve this requirement using optical profilers the camera frame rate must be increased while reducing the sensor’s size and mass as to improve the dynamics of the mechanical scan.
In this paper we analyze the performance characteristics of a linear stage with a linear brushless motor in terms of travel range, accuracy and repeatability compared to a linear stage driven by a stepper motor. The linear stage with brushless motor moves only the objective instead of the whole sensor, enhancing the acceleration dynamics. Additionally, we propose applying different movement profiles to the motor. These new profiles aim to minimize the system’s downtime caused by the acceleration and deceleration of the motor, as all the aforementioned metrology technologies require a very stable constant speed when scanning continuously. The downtime reduction leads to a faster acquisition rate, allowing for real-time 3D topographies to be obtained.
Full abstract and technical poster at Virtual International Conference Programme .
