Glass Canada

Automation Inspection and Closing the Loop

February 14, 2023 
Sponsored by LiteSentry-Softsolution

LiteSentry-Softsolution has been developing technologies to solve the hard problems of inspection and measurement for glass fabricators for over 20-years. Our tools provide automated, accurate, quantifiable, 100% on-line inspection of flat glass and plastic sheets for manufacturers around the world. At the heart of our business is a passion for new technology that solves our customers’ most difficult challenges. In this article, you will read about automated inspection for distortion, anisotropy, quality, and closing the loop on process control, lowering cost, increasing throughput, and improving customer satisfaction.


Distortion is the localized warpage of the glass caused by heat-treatment. Glass tempering and heat-strengthening involve heating and controlled cooling of the product to set up an internal stress gradient. This process always imparts some physical distortion. This causes reflected and transmission images to be optically distorted. Without an automated process controlling this distortion, it can easily reach objectionable levels.

To the left is an example of two of the more prevalent types of glass distortion known as roller-wave and hammer or pocket distortion.



Anisotropy manifests as a ghostly pattern of dark and light areas in a piece of glass when it is exposed to a polarized light source. A tempering process creates high surface and centre stresses. In practice tempering always creates areas of unbalanced stress. These areas of imbalance will affect light differently causing visibly ghostly iridescence patterns under certain lighting conditions. Measuring stress in the glass in real-time allows for process control and quality control of iridescence.

Quality Detection

Optical defects such as scratches, inclusions, edge chips, screen printing, mutton bars as well as dimensional defects with regard to overall dimensions, drill hole diameter and hole location is a difficult inspection issue. These issues can end up with costly remakes and customer dissatisfaction. Automated Inspection systems provide high-resolution inspection of both front and rear surfaces of monolithic glass. They are designed for insulating, double, or triple glazing, lamination, and coating lines. The result: defective glass is caught and removed from the production line before assembly or adding cost with further processing.

Closing the Loop with Recipe Selection Plus Load Validation

Operator inexperience can be a common issue when there is high employee turnover. Operators are also human and can cause inconsistent production operation. With automation this is not an issue that will occur any longer. Automation can transmit data to the furnace control system allowing the furnace to automatically select a recipe and optimize the heat profile, improving cycle time, minimizing distortion, and optimizing flatness. By automating the process, you will have your best furnace operator on every shift, which will increase throughput and quality.


The LineScanner can be installed in a horizontal or vertical position on your IG, laminate, or tempering line. It is the solution for all quality inspections of transparent flat glass products such as single sheets, insulating glass, automotive glass, processed glass, polycarbonate, or film. LineScanner inspects your products with extreme precision for all defects in quality and dimension. Its flexibility as well as its simple operation and installation allow it to be put into operation quickly and easily with minimum space requirements.

The unique telecentric inspection technology enables true scanning and to be operated with the same setup to inspect single sheets as well as finished insulation elements both horizontally and vertically. An automatic glass defect inspection system that excels with maximum flexibility and extreme ease of use.

Osprey® 10 Advance Inspection Systems

LiteSentry’s revolutionary Osprey 10 advanced inspection systems include the only high-performing systems that meet and exceed the growing requirements of leading architects and glass suppliers, including mandated distortion and anisotropy measurements.

Innovative optical technology delivers real-time, on-line, complete, precise, quantified, and accurate inspections guaranteeing superior quality while saving time and costs. Secure customer commitments and advance your opportunities with Osprey. The only proven optical distortion system in the world – with first order measurement made in diopters. 

The Owl 5®

The Owl 5 is a patented, non-contact optical system measuring the glass thickness, type of low-E coating (1, 2, 3 silver layers, 4th surface low-E), colour, glass dimensions, and sheet locations as the load approaches the furnace.

The Owl 5 transmits data to the furnace control system allowing the furnace to automatically select a recipe and optimize the heat profile, improving cycle time, minimizing distortion, and optimize flatness. The system is for loads entering a batch or continuous tempering furnace. With the Owl 5 Furnace Optimization System, you will have your best furnace operator on every shift.

Contact us at (507) 645-2600 or at for more information.

Print this page


Stories continue below


Leave a Reply

Your email address will not be published. Required fields are marked *