Patent ID: 11906357
Assignee: X-RITE EUROPE GMBH
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An illumination device for a spectral optical measurement device, the illumination device comprising:
a light source arranged with respect to an optical axis of the illumination device which, during a measurement operation, extends along a normal to a center point of an area of a sample to be illuminated; and
a mirror comprising at least one mirror segment shaped as a ring or as a segment of a ring centered on the optical axis, the mirror segment having an internal reflective surface arranged such that, during the measurement operation, the internal reflective surface receives light emitted from the light source and reflects the light over the area of the sample to be illuminated,
wherein the mirror segment comprises at least two facets along a direction which runs circularly around the optical axis,
wherein, in each facet, the internal reflective surface has a freeform shape in a cross-section through the mirror segment in a plane parallel to the optical axis, and
wherein, in each facet, the internal reflective surface has a shape of a straight line in a cross-section through the mirror in a plane perpendicular to the optical axis.