Luminaire and method for temperature control

• US 10,317,286 B2
• Filed: 09/10/2014
• Issued: 06/11/2019
• Est. Priority Date: 11/29/2013
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Inventors: Ott, Toni
• Primary Examiner(s): A, Minh D
• Assistant Examiner(s): Cho, James H
• Application Number:
  US15/100,253
• Publication Number:
  US 20160377484A1
• Time in Patent Office: 1,735 Days
• Field of Search: None
• 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 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.