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

Claim 10:
11. A method for illuminating a sample during a measurement operation using the illumination device according to claim 1, the method comprising:
emitting light using a light source arranged with respect to an optical axis of the illumination device which extends along a normal to a center point of an area of a sample which is illuminated during the measurement operation; and
deflecting the light by an internal reflective surface of at least one mirror segment of a mirror in a shape of a ring centered on the optical axis, the internal reflective surface being arranged such that the internal reflective surface receives the light emitted from the light source and reflects the light over the area of the sample, the mirror segment comprising at least two facets along a direction which runs circularly around the optical axis, the internal reflective surface in each facet having a freeform shape in a cross-section through the internal reflective surface in plane parallel to the optical axis, and, in a cross-section of the mirror in a plane perpendicular to the optical axis, the internal reflective surface in each facet being represented by a straight line.