Luminaire for illuminating a target area by means of retroreflection of light from a light-emitting diode module on a reflector

A luminaire for illuminating a target area by retroreflection from a reflector, comprising:

• a light-emitting diode module having at least one light-emitting diode;
• and
• a cooling device for the light-emitting diode module, the cooling device including as coolant a liquid that is transparent to the light of the light-emitting diode module and a transparent coolant container for accommodating the coolant;
• wherein the coolant container comprises a first and a second transparent wall between which the coolant is located and which extend substantially perpendicularly to the optical axis of the reflector and have a surface such that in an assembled state in which the light-emitting diode module and the cooling device are connected to the reflector, at least 90% of the radiation of the light-emitting diode module which is reflected from the reflector and which reaches the target area passes through the coolant container;
• wherein the cooling device additionally serves as a retainer for the light-emitting diode module;
• and
• wherein the light-emitting diode module includes a thermally conducting element which is coupled to the at least one light-emitting diode and which is recessed into the coolant container such that it is in contact with the coolant.