System for use with application unit for applying fluid on surface, has coupled illumination unit, which illuminates surface directly area by area, where illumination unit radiates light in varying light emission angle

摘要

The system has a coupled illumination unit (100), which illuminates the surface directly area by area and a contrast is distinguished between a surface portion (22) without application of fluid and another surface portion (24) with application of fluid. The illumination unit radiates light in varying light emission angle or with different wavelengths.