The Stinger Thermal Grid Inspection System

In the production of backlights (rear windows for automobiles) quality of product, long term durability of heater grid, and throughput directly influence production and product costs. IRCON has announced a complete system that will directly reduce backlight costs to the automobile manufacturers – the Stinger Thermal Grid Inspection System. In using this new system, automobile manufacturers save by reducing product cost, post sale warranty and incoming inspection/handling costs. For the producers of the backlights, the savings are focused on reduced production costs through more rapid inspections and greater reliability of inspections which leads to less reordering due to incorrect scrapping of good product. The manufacturers who worked with IRCON on the development of this product have realized a return on investment in fifteen weeks.

The new IRCON Stinger Thermal Grid Inspection System is the first infrared system of its kind capable of inspecting multiple Areas of Interest (AOIs) in only two seconds: The Line Checker AOI detects broken grid lines that aren't generating enough heat to be considered good; and the Hot Spot AOI locates hot spots that are associated with a neck-down or thinned out grid line. This system – designed for the automotive, glass, aerospace and aircraft industries – includes software that works in conjunction with the IRCON Stinger, a radiometric digital thermal imaging camera that provides high quality, real-time video temperature representation of process control applications.

Using the Stinger with the Thermal Grid Inspection software, closed-loop process control outputs are coordinated, reducing inspection cycle time and set-up cost. Just load parts, align voltage probes and apply voltage.

All inspection parameters are set-up and monitored by the software, eliminating mechanical movement of the Stinger and minimizing the need for robotic equipment. In addition, the software permits files for different parts to be loaded from a remote host computer or PLC.

After the backlight is loaded for inspection, the software system grabs a frame of data. This reference frame represents the Master Image and is used to establish both the target signature prior to energizing the grid, and the AOI set points. Voltage is then applied to the grid to heat it up and the application software looks for differential temperatures for each grid pixel based on the Master Image. Any pixel that has a differential temperature exceeding either the Line Checker AOI or the Hot Spot AOI set points will trigger an audible alarm, signifying a defective grid. When defects are found, the backlight's thermal image can be automatically archived for quality control purposes, capturing information such as: defective AOI, defective line in the AOI, and value of the differential within the AOI that exceeded the threshold. The software displays the absolute temperature of the backlight as well as the differential temperature.

Overall, the IRCON Stinger Thermal Grid Inspection System offers improved reliability – avoiding passing bad parts due to the system's ability to detect hot spots, and eliminating the chance of thermocouple wear on parts that could result in good parts failing inspection. It also allows selection of appropriate "apply power time" for the condition where the part ambient temperature is highest so varying incoming part ambient temperatures do not affect inspection.