Patent ID: 8767218

Claim:
An optical arrangement for non-contact determination of a property of a solid's surface, comprising: structure that establishes a gap between the solid's surface and a reference edge, wherein the reference edge is part of a gauge and defines a direction of a tangent line to the solid's surface, and the distances between the solid's surface and the reference edge, seen in the direction of a normal to the tangent line, define gap widths, structure that images the gap onto a spatially resolving detector, a light source integrated in the gauge, wherein radiation of the light source is directed at a zone of the solid's surface facing the reference edge through a focusing optical system, an analyzing system connected to the detector, configured to determine gap widths lying adjacent to each other in the direction of the tangent, on the basis of the output signals of the detector, and to determine the property of the solid's surface, on the basis of the gap widths lying adjacent to each other along the tangent.