Luminaire and method for temperature determination

A method for temperature control of at least one LED as a light source of a luminaire with the following steps:

• i) arranging an infrared sensor within an area of black body radiation of the light source and outside a light emitting angle of the light source, wherein the infrared sensor is disposed in a housing of the luminaire and detached from a light source assembly that comprises:
• the light source that is disposed in the housing, and
• a cooling device on which the light source is disposed,
• wherein within the housing, the light source assembly is positioned relative to the therefrom detached infrared sensor such that the cooling device of the light source assembly is disposed outside an area of the black body radiation that is detected by the infrared sensor;
• ii) measuring a black body radiation of the light source by the infrared sensor,
• iii) evaluating an infrared signal of the infrared sensor for contactless determination of temperature of the light source using the black body radiation of the light source;
• and
• iv) measuring ambient heat radiation by a second infrared sensor for compensation of the ambient heat radiation,
• wherein the compensation of the ambient heat radiation based on a measurement of the ambient heat radiation by the second infrared sensor comprises:
• assigning weights to:
• a value of the black body radiation of the light source that is detected by the infrared sensor, and a value of the ambient heat radiation from an external source that is detected by the second infrared sensor,
• wherein the external source is the sun, and
• wherein the weights are assigned based on a position of the sun.

A luminaire comprising:

• a housing;
• a first infrared sensor that is disposed in the housing;
• and
• a light source assembly that is disposed in the housing, wherein the light source assembly comprises:
• a circuit board having a first surface and a second surface that is opposite to the first surface;
• at least one light emitting diode (LED) as a light source disposed on the first surface of the circuit board, wherein the at least one LED has a light emitting angle for an emitted light radiation;
• and
• a cooling device disposed on the second surface of the circuit board that is opposite to a direction of the emitted light radiation,
• wherein the first infrared sensor is detached from the light source assembly such that the first infrared sensor is not mounted on the cooling device of the light source assembly and is configured for contactless determination of temperature of the at least one LED by detecting black body radiation of the at least one LED,
• wherein the first infrared sensor is disposed within an area of the black body radiation of the at least one LED and outside of the light emitting angle of the at least one LED, and
• a second infrared sensor that is configured to measure ambient heat radiation for compensation of the ambient heat radiation,
• wherein compensating for the ambient heat radiation comprises assigning weights to:
• a value of the black body radiation of the light source that is detected by the infrared sensor, and a value of the ambient heat radiation from an external source that is detected by the second infrared sensor,
• wherein the external source is the sun, and
• wherein the weights are assigned based on a position of the sun.