Luminaire and Method for Temperature Control

• US 20160377484A1
• Filed: 09/10/2014
• Published: 12/29/2016
• Est. Priority Date: 11/29/2013
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Protection Systems Ip Gmbh & Co. Kg (Eaton Corporation PLC.)
• Inventors: Ott, Toni
• Granted Patent: US 10,317,286 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F21V 23/0457 the sensor sensing the operating status of the lighting device, e.g. to detect failure of a light source or to provide feedback to the device
• CPC Class Codes: F21V 25/10 coming into action when lighting device is overloaded, e.g. thermal switch
• CPC Class Codes: F21V 29/50 Cooling arrangements air-treatment systems dissipating or using the heat of lighting fixtures F24F3/056
• CPC Class Codes: F21V 9/20 Dichroic filters, i.e. devices operating on the principle of wave interference to pass specific ranges of wavelengths while cancelling others
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G01J 2005/608 Colour temperature of light sources
• CPC Class Codes: G01J 5/041 Mountings in enclosures or in a particular environment
• CPC Class Codes: G01J 5/047 Mobile mounting; Scanning arrangements
• CPC Class Codes: G01J 5/10 using electric radiation detectors
• CPC Class Codes: G01J 5/60 using determination of colour temperature
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/18 using temperature feedback

Abstract

A luminaire comprises at least one light emitting diode (LED) as a light source. Such LED has a limited light emitting angle for emitted light radiation. An infrared sensor is assigned to the light source for determining the temperature of same.

Claims

1. A luminaire (1) with at least one light emitting diode (LED) (2) as a light source (3), which LED (2) has a limited light emitting angle (4) for emitted light rays, wherein within the light emitting angle an infrared sensor for determining a temperature of the light source (3) is assigned to the light source.

2. The luminaire according to claim 1, wherein the infrared sensor (6) in a peripheral area of the light cone or efficient light flux is directed to the light source (3).

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

4. The luminaire according to claim 1, wherein the infrared sensor (6) is connected to an evaluation/control means (8) for the determination of temperature and control of the light source.

5. The luminaire according to claim 1, wherein the infrared sensor (6) is arranged in a luminaire housing (9).

6. The luminaire according to claim 1, wherein the evaluation/control means (8) includes a maximal temperature threshold as a preset switch off value.

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

8. The luminaire according to claim 1, wherein the infrared sensor (6) is shielded from ambient heat radiation and/or light radiation of the light source using a screening device.

9. The luminaire according to claim 1, wherein the screening device has several parts including a reflector and/or a dichrotic mirror or filter.

10. The luminaire according to claim 1, wherein a second infrared sensor (10) is assigned to the infrared sensor (6) for detecting and compensating the ambient heat radiation.

11. The luminaire according to claim 1, wherein the infrared sensor (6,10) is arranged in an adjustable way.

12. The luminaire according to claim 1, wherein the infrared sensor (6) is a ratio or 2-ray-pyrometer.

13. A method for temperature control of an LED (2) as a light source (3) of a luminaire (1) comprising of the following steps:

i) arranging of an infrared sensor (6) within light emitting angle (4) of the light source (3);

ii) measuring a heat radiation of the light source (3) by said infrared sensor (6); and

,

iii) evaluating the infrared signal for temperature determination of the light source (3).

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

switching off the light source (3), in case the measured temperature value is higher than a preset maximum temperature threshold.

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

screening the infrared sensor (6) with respect to ambient heat radiation and/or light radiation of the light source (3).

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

measuring of the ambient heat radiation by a second infrared sensor (10) for compensation of ambient temperature.

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

assigning of the infrared sensor (6,10) to an LED-spotlight, an LED-strip, or an LED-ribbon as light source (3).

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

reducing of the power usage of the light source, when the measured temperature value passes a preset maximum temperature threshold, in particular until a preset cooling temperature value is reached.

19. The method according to claim 13, characterized in that in step iii) the infrared temperature determination is realized by determination of deviations in a relation of emitted light spectrum to infrared spectrum at a particular ambient temperature.

20. The method according to claim 13, characterized in that for temperature determination deviation of the infrared distribution is measured.