Automotive Inspection with Line Lights High Current, High Intensity LED Line Lights Offer Flexible Option

Until recently, vision integrators were faced with relatively limited task oriented, high intensity illumination choices. For example, options for inspecting vehicle doors and body panels on the automotive manufacturing plant floor were often limited to either fluorescent tube or fiber optic lights.

Until recently, vision integrators were faced with relatively limited task oriented, high intensity illumination choices. For example, options for inspecting vehicle doors and body panels on the automotive manufacturing plant floor were often limited to either fluorescent tube or fiber optic lights. Although both light types provided adequate illumination for some vision inspections, there were also limitations; fluorescent lights were unstable, diffuse, and had a short life span, whereas fiber optic bundles and sources were bulky, expensive to install, and the light source had to be replaced approximately every 500 hours. In both cases, relatively frequent light changes required implementing a maintenance schedule, decreasing the efficiency of the inspection and increasing the real cost of the light. Today, however, integrators have a new option for large object, task-oriented illumination. The development of high current, high intensity output LEDs extends the application range of a light source that has, in recent years, come to dominate many areas of machine vision illumination. Taking advantage of the benefits of the new LED technology, Advanced illumination has created a line of standard and custom length line lights. Recently a pair of custom length high current red (625nm) line lights was tested for suitability in a B&W camera body panel inspection system. Other light options were tested and rejected, including a large area flood or diffuse lights, and a robotic arm mounted with a vision system and a smaller light source requiring multiple passes. The high intensity line lights, placed opposite each other at a very low angle of incidence and at a large distance, produced dark field illumination, allowing the vision system, mounted directly above the production line, to detect very minor surface defects over a large area in a single pass as the parts passed below.