Flawlessly coated glass from every perspective

Detection of smallest color deviations and coating defects – with advanced inspection technology for ribbon and plates - In architecture, coated glass is considered a standard option in new construction projects.  These days, coating fulfills many important functions, especially with regard to thermal insulation and saving energy. This is only possible due to the progress in online and offline coating processes, which have become much more complex. However, this also uncovers new defect types, which make it even more difficult to assure flawless coating quality and color homogeneity. ISRA VISION offers a wide array of optical inspection systems, specifically designed in response to the new challenges in the field of glass coating. The innovative inline technologies deliver guaranteed defect-free results and a uniform color appearance, even on larger coated glass surfaces. Moreover, they also supply important data that can be used for process optimization, thus activating savings potential.

Perfect quality, maximum output: 100% inline inspection of glass for color, coating and glass defects.

The prerequisites for optical quality inspection are conceivably high: Contemporary building glass coating is only just a few μm thick and changes color depending on the viewing perspective. Even the smallest irregularity in coating thickness in the nanometer range can lead to inconsistencies in color. In order to be able to inspect reliably under these conditions, ISRA systems supply a top-rate performance. Equipped with high-resolution color cameras, advanced LED illumination technology, which covers the entire visible spectrum, and the highly-developed algorithm-based software, all typical defects are detected reliably at a very early stage. The solutions can be used for any type of coating and for any process: pyrolytic coatings applied online in ribbon applications, magnetron coatings applied offline in plate applications on multiple levels and technical offline coatings such as TCO, E/C and anti-reflex.

All coating errors, color irregularities and glass defects are reliably detected by ISRA technology.

Secure focus on color-coated glass surfaces: pictured here is the detection of a cathode defect which would not have been identified with point-related measurement methods.

Color channel technology for large-scale color homogeneity Contractors and architects only accept color-coated glass plates with large-scale color homogeneity, visible from every perspective. In order to inspect this with 100% accuracy and across the entire surface, ISRA has developed Color Channel as the latest option in the proven line of inspection features. In this way, it is possible to completely monitor color variations in ΔE and to calculate color deviations in ΔC, Δa*, Δb* etc. using a finely tuned interaction between LED illumination and RGB cameras. The slightest deviations and low-contrast defects are identified, recorded and visualized without requiring any additional cameras or illumination setups. Until just recently used, complicated punctual measurements with spectrometers are being traded in for a much more efficient and reliable automated inspection solution. Now, even complaint scenarios which are typically extremely expensive are a thing of the past.

For a uniform visual appearance: glass color from different viewing angles ensured by the universally applicable Color Angle Shift method. The figure illustrates a possible color gradient from different views.

Conclusion

With the use of innovative technologies, optical ISRA systems now provide a reliable solution to 100% quality inspection of coated glass, the realization of which has been inadequate until now. Integrated analysis tools supply detailed inspection data, with which users can adjust production parameters, saving costs and resources.