Fast 3D sensors for 100% in-line quality control are rare. Heavy demands on speed exclude most of the available measurement devices. This article introduces a new measurement principle for this purpose, combining the chromatic confocal and the triangulation principle. The result is an optical line scan measurement device that measures the 3D topology of specular and diffuse surfaces in absolute coordinates. The sensor system consists of an optical design, optimized optical filters, and a multi channel line scan camera. The filters are derived using information and coding theory and a proposed physical motivated color space transformation

The probably best known chromatic sensor is the chromatic confocal point sensor, which is an optical displacement sensor (depicted in Fig. 1). It uses different wavelengths to encode the distance and has one measurement spot. Beside this prominent example, there are plenty of other realizations. E.g. Lee lists fiber optical sensors which measure temperature, displacement, current, strain and more. A variant of the chromatic confocal point sensor is used within this paper as example to apply the proposed method, referred to as CCT (chromatic confocal triangulation) sensor. In contrast to the point sensor the CCT sensor has many measurement spots next to each other (typically 2000 measurement spots in a row)

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