Inspection of display components
Various types of display units for tractors need to be inspected using machine vision in a test cell. They are normally fed manually from a manual work station, which has a master computer for actuating the display functions. The machine vision system performs a range of tasks including pointer position monitoring, segment inspection on LCD displays, measurements, symbol monitoring and lamp function tests.
The CV-600 machine system for monitoring display components provides free configuration of all tasks and enables them to be performed in several inspection sequences and image captures. Because of the total size of 340 mm x 170 mm and the small LCD size, two high resolution cameras are used. One camera inspects the complete unit, the other camera the LCD display. The positions of the pointers on the two main components can thus be determined accurate to less than 1°, despite the resolution of 0.25 mm x 0.25 mm per pixel. The entire inspection cycle takes around 10s due to the range of inspections and images. The necessary illumination is briefly activated for each of the tasks.
An objective, qualitative and quantitative inspection with this scope is almost impossible with the human eye when large quantities are produced. Machine vision enables faults from a defective lamp through to incomplete or offset printed markings or malfunctioning LCD displays to be detected. This is the only way to deliver products that satisfy today’s stringent quality demands.