Automatic electro-optical testing of automobile dashboard displays in a factory environment

The use of sophisticated, computer-driven, vacuum-fluorescent displays for automobile instrumentation readouts on the dashboards of 1990 vehicles has forced the development of a reliable test solution. Volume production of these displays with over 100 elements precludes the use of a human inspector. Microspot photometry exacerbates the test problem owing to the elemental variations in phosphor luminance and the prohibitive test time required to test each display on that basis. The author describes the solution taken and proved in production runs, which uses a unique fibre optic macroflux photonic probe developed specifically for this test problem. Through the use of a mix of macro and micro field-of-view probes, both small and very large 'anodes' could be checked for brightness levels without using an excessive number of probes and ATE (automatic test equipment) driver-sensors. Test time was kept to a minimum, and a high degree of quality in the finished product was achieved.<>