Luminaire and method for temperature control

1. A luminaire with at least one light emitting diode (LED) as a light source, which LED has a limited light emitting angle for emitted light rays, wherein within the limited light emitting angle an infrared sensor for determining a temperature of the light source is assigned to the light source, and wherein a second infrared sensor is assigned to the infrared sensor for detecting and compensating for an ambient heat radiation.

2. The luminaire according to claim 1 , wherein the infrared sensor is located in a peripheral area of a light cone or efficient light flux and is directed toward the light source.

3. The luminaire according to claim 1 , wherein the light source is an LED-spotlight, an LED-stripe, or an LED-illumination ribbon.

4. The luminaire according to claim 1 , wherein the infrared sensor is connected to an evaluation/control device, wherein the evaluation/control device is configured to determine the temperature of and control the light source.

5. The luminaire according to claim 4 , wherein the evaluation/control device includes a maximal temperature threshold as a preset switch off value.

6. The luminaire according to claim 1 , wherein the infrared sensor is arranged in a luminaire housing.

7. The luminaire according to claim 1 , wherein the infrared sensor is arranged in an adjustable way.

8. The luminaire according to claim 1 , wherein the infrared sensor is a ratio or 2-ray-pyrometer.

9. The luminaire of claim 1 , wherein after measurement of a preset temperature, a power reduction of the luminaire is performed to reduce the temperature.

10. A luminaire with at least one light emitting diode (LED) as a light source, which LED has a limited light emitting angle for emitted light rays, wherein within the limited light emitting angle an infrared sensor for determining a temperature of the light source is assigned to the light source, wherein the infrared sensor is shielded from an ambient heat radiation and/or visible light radiation of the light source using a screening device.

11. The luminaire according to claim 10 , wherein the screening device has several parts including a reflector and/or a dichrotic mirror or filter.

12. A method for temperature control of an LED as a light source of a luminaire comprising of following steps:

i) arranging of an infrared sensor within a light emitting angle of the light source;

ii) measuring a heat radiation of the light source by the infrared sensor; and

iii) evaluating an infrared signal for temperature determination of the light source, characterized in that in step iii) the temperature determination is realized by determination of deviations in a relation of emitted light spectrum to infrared spectrum at a particular ambient temperature.

13. The method according to claim 12 , characterized by the further step of:

switching off the light source, in case a temperature value determined in step iii) is higher than the preset maximum temperature threshold.

14. The method according to claim 12 , characterized by a further step of:

screening the infrared sensor with respect to an ambient heat radiation and/or light radiation of the light source.

15. The method according to claim 12 , characterized by the further step of:

measuring of an ambient heat radiation by a second infrared sensor for compensation of an ambient temperature.

16. The method according to claim 12 , characterized by the further step of:

assigning of the infrared sensor to an LED-spotlight, an LED-strip, or an LED-ribbon as the light source.

17. The method according to claim 12 , characterized in that for temperature determination deviation of an infrared distribution is measured.

18. The method of claim 12 , further comprising: reducing the power usage of the light source, when a temperature value determined in step iii) passes a preset maximum temperature threshold, until a preset cooling temperature value is reached.