Lighting Device Having a Compact Lighting Dome for Forming an Illumination Spot of Variable Diameter and of Variable Color Temperature

摘要

A lighting device for illuminating an operative field comprises, in an axial lighting dome, a first ring of LEDs at a first color temperature, and a second ring of LEDs at a second color temperature different from said first color temperature, and an annular facetted mirror having semi-reflective facets and arranged about the same axis as said rings of LEDs. Collimation optical systems are provided between each ring of LEDs and the annular facetted mirror having semi-reflective facets. The annular facetted mirror having semi-reflective facets mixes the collimated light beams emitted by the two rings of LEDs coupled to the collimators, and forms first and second collimated resulting mixed light beams having the same intermediate color temperature. An annular facetted mirror having plane facets surrounds the annular facetted mirror having semi-reflective facets so as to reflect the first collimated resulting mixed light beam to combine it with said second collimated resulting mixed light beam in the operative field in a certain superposition configuration in a superposition plane in which an illumination spot is formed.

主权项

1. A lighting device for illuminating an operative field, the lighting device comprising:
an axial lighting dome, a first ring of LEDs arranged about an axis in the axial lighting dome, said first ring of LEDs being suitable for emitting a first light beam at a first color temperature, a second ring of LEDs arranged about the same axis as said first ring of LEDs and suitable for emitting a second light beam at a second color temperature different from said first color temperature, an annular facetted mirror having semi-reflective facets and arranged about said axis for mixing said light beams emitted by said two rings of LEDs and for forming two resulting mixed light beams having the same intermediate color temperature lying between said first color temperature and said second color temperature, an annular optical system that surrounds said annular facetted mirror having semi-reflective facets so as to reflect said first resulting mixed light beam onto said operative field to combine it with said second resulting mixed light beam in a certain superposition configuration in a superposition plane in which an illumination spot is formed at said intermediate color temperature, wherein said annular optical system that surrounds said annular facetted mirror having semi-reflective facets is a total reflection annular facetted mirror having plane facets that are substantially geometrically similar to said semi-reflective facets, and collimation optical systems between each ring of LEDs and said annular facetted mirror having semi-reflective facets.