Optical Field Metrology For Surface Inspection
Equipments for Optical Field Metrology
Existing quality control processes often lack automated inspection systems and must therefore rely on inefficient manual visual control. As a result, VIRELUX was established to provide advanced solutions for high quality inspection requirements, based on contact-less control of large-field surfaces.
The core competency of VIRELUX lies in the development of dedicated, state of the art, solutions aimed at modernizing critical quality control processes.
The company has established itself in the market of surface quality inspection with its OptiFrag & OptiGlass Audit Stations for the automotive glazing industry. Both using VIRELUX' proprietary Structured Light Generators, that can also be assembled into standalone, dynamic inspection systems: OptiLux.
Reflection on the car's body of the displayed pattern, allowing the analysis of the surface and detection of defects through metrology.
Defect put into light by the grey-level pattern transition
It is quite uncommon to find a company with a strong metrological vocation that also boasts a robust expertise in mechanical engineering. The atypical skill combination provides a unique knowledge platform for the development of novel industrial-grade, metrology equipment.
Optical field metrology requires very specific and accurate light sources. The light source is fundamental for deflectometry-driven temporal shift analysis, particularly for large-surface or complex shape measurements. State of the art solutions would require curved, dynamic and continuous light source.
VIRELUX Inspection Systems has therefore specialized in the latest available display technology, building its own proprietary modular LED screens. Specifically engineered for metrology applications, ranging from audit stations to dynamic light tunnels.
LED displays have been engineered from the beginning with a modular system in mind, thus allowing the integration of LED displays specifically tailored to each metrology application.
These modular displays are now at the heart of VIRELUX’ inspection systems.
Missioned by Asahi Glass Co., Ltd. (AGC) to automate and digitize their outdated manual fragmentation testing process, VIRELUX developed an automated audit station able to execute the entire fragmentation counting (and more) in less than a minute, and providing digital results in accordance with the latest applicable standards.
VIRELUX also managed to eliminate the need for photosensitive film paper on which the traditional process is critically dependent. (True revolution behind this development, as global production of photosensitive film is dwindling at an alarming rate)
Additionally, the OPTIFRAG Audit Station also enables the analysis of areas with serigraphy and/or tinted glass, both being impossible with the old process.
Other indirect benefits also include:
The insensitivity to defrosting wires that can create erroneous measurements.
The ability to migrate the legally needed result archiving from a bulky paper-based, physical storage to a digital one.
The ability to digitally exploit the results for statistical analysis.
And, most critically, the ability to exchange a fastidious and subjectively unreliable operator-based counting process with the accuracy and consistency of a computer:
The comparative trials with experienced operators have highlighted a statistical deviation of less than 0.50 % for the longest and largest fragments in the repeatability of the OptiFrag Audit Station. To be compared with a standard-deviation ranging between 5.00 % and 24% among experienced operators.
The same repeatability accuracy has also been found in the detection of the minimum and maximum densities, at respectively 1.82% and 2.78 % deviation from the mean for the OptiFrag equipment. To be compared with standard deviations ranging between 6.00 % to 22 % among operators.