Lighting system

• US 9,210,761 B2
• Filed: 08/30/2012
• Issued: 12/08/2015
• Est. Priority Date: 09/02/2011
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Nackaerts, Axel, Nguyen, Viet Hoang
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): Kaiser, Syed M
• Application Number:
  US13/599,118
• Publication Number:
  US 20130057157A1
• Time in Patent Office: 1,195 Days
• Field of Search: 315/154, 315/158, 315/151, 362/231
• US Class Current: 1/1
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/22 using optical feedback
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A lighting system uses interior and exterior light sensors for detecting lighting level and color. A lighting unit has a controlled color and intensity so that a color match zone can be defined where the interior space lighting has color temperature based on the exterior lighting conditions.

Claims

1. A lighting system for an interior space comprising:

a first light sensor configured and arranged to indicate at least one exterior lighting colour;

a second light sensor configured and arranged to indicate an interior lighting level and at least one colour of an interior lighting space;

a lighting unit having adjustable colour and intensity; and

a controller for controlling the lighting unit, wherein the controller is adapted to

adjust the colour and intensity of the lighting unit based on the light sensor indications including multiple exterior natural-light-source lighting colour indications provided by the first light sensor and interior lighting colour indications provided by the second light sensor, to obtain a colour gradient that is between a colour match zone where the interior space lighting has a colour temperature dependent on the multiple exterior natural-light-source lighting colour indications at different times during a course of a day and a defined colour zone.

2. A system as claimed in claim 1, wherein in the colour match zone, the interior space lighting has a colour temperature matched to the colour temperature of the exterior lighting, when the exterior lighting colour temperature is within upper and lower bounds during the course of a day and is indicative of preset or expected natural-light conditions, wherein the upper and lower bounds include thresholds of the interior space lighting matching the exterior lighting.

3. A system as claimed in claim 1, wherein in the colour match zone, the interior space lighting has a light intensity matched to an exterior light intensity, when the exterior light intensity is within upper and lower bounds during the course of a day and is indicative of preset or expected natural-light conditions, wherein the upper and lower bounds include thresholds of the interior space lighting matching the exterior lighting.

4. A system as claimed in claim 1, further including a timer configured and arranged for providing a time of day signal to the controller, and the controller further adapted to disable the adjustment of the lighting unit when the time of day is outside a pre-configured time period, whereby the colour and intensity of the lighting unit is adjusted to a default profile.

5. A system as claimed in claim 1, further including at least one other lighting unit, the controller configured and arranged to adjust the colour and intensity of each lighting unit based at least in part on exposure of the interior light sensor for each of the respective lighting units to exterior light and to prevent colour boundaries between the exterior and interior light within the colour match zone by matching the colour indications at least in the vicinity of a window.

6. A system as claimed in claim 1, comprising a plurality of light sensors for the interior space.

7. A system as claimed in claim 1, wherein the lighting unit comprises LED light fixture.

8. A system as claimed in claim 1, wherein the controller is further adapted to:

adjust the colour and intensity of the lighting unit based on user input thereby to obtain the defined colour zone, and to provide the colour gradient and an intensity gradient between the defined colour zone and the colour match zone to prevent a mismatch in colour temperature and intensity between the defined colour zone and the colour match zone during a period of time of the day.

15. A system as claimed in claim 1, wherein the controller is further configured and arranged to

adjust a colour of interior light provided by the lighting unit in the colour match zone to match the indicated exterior lighting colour;

and

adjust intensity of the lighting unit based on a total light intensity of interior light and exterior light in the colour match zone.

16. A lighting system as claimed in claim 15, wherein the controller is further configured and arranged to adjust the lighting unit to obtain the colour match zone when a current output of the first lighting sensor associated with lighting colour is within a pre-configured upper and lower threshold and to adjust the lighting unit to a pre-configured interior lighting colour when the current output of the first light sensor is outside the pre-configured upper and lower thresholds.

17. A system as claimed in claim 15, further including a timer configured and arranged for providing a time of day signal to the controller, and the controller is further configured and arranged to disable the adjustment of the lighting unit when the time of day is outside a pre-configured time window and whereby the colour and intensity of the lighting unit is adjusted to a default colour and intensity.

18. A system as claimed in claim 15, wherein the controller is further configured and arranged to adjust the light intensity of the lighting unit based on a current output of the first light sensor associated with light intensity when the current output of the exterior lighting is within a pre-configured upper and lower intensity threshold, and adjust the light intensity of the lighting unit to a pre-configured interior lighting intensity when the current output is outside the pre-configured upper and lower thresholds.

19. A system as claimed in claim 15, wherein the controller is further configured and arranged to identify rapid light intensity fluctuations in a current output of the first light sensor, the current output indicative of light intensity, and to dampen the adjusting of the intensity by the controller.

9. A method of controlling a lighting system for an interior space, comprising:

monitoring an exterior lighting colour indicated by a first light sensor;

monitoring an interior lighting level and colour indicated by a second light sensor; and

controlling a lighting unit to;

adjust the colour and intensity based on the colour indications of the exterior lighting colour and indications of the interior lighting colour thereby to define a colour match zone where the interior space lighting has a colour temperature dependent on the exterior lighting, wherein the adjustment of the interior space lighting takes place when the exterior lighting is within upper and lower bounds during a course of a day and is indicative of preset or expected natural-light conditions; and

adjust the colour of the lighting unit to obtain a defined colour zone, and to provide a colour gradient between the defined colour zone and the colour match zone.

10. A method as claimed in claim 9, wherein in the colour match zone, the interior space lighting is controlled to have a colour temperature matched to the colour temperature of the exterior lighting, when the exterior lighting colour temperature is within the upper and lower bounds, wherein the upper and lower bounds include thresholds of the interior space lighting matching the exterior lighting.

11. A method as claimed in claim 9, wherein in the colour match zone, the interior space lighting is controlled to have a light intensity matched to an exterior light intensity, when the exterior light intensity is within the upper and lower bounds.

12. A method as claimed in claim 9, comprising using a timer to provide a time of day signal to the controller, and disabling the adjustment of the lighting unit when the time of day is outside a pre-configured time window and whereby the colour and intensity of the lighting unit is adjusted to a default profile.

13. A method as claimed in claim 9, comprising:

measuring an external light colour temperature;

calculating a spectrum difference between the external light colour temperature and a desired internal lighting colour temperature;

controlling the lighting unit to add the calculated missing part of the spectrum thereby to change the internal lighting colour temperature; and

adding light to adjust the intensity to a desired internal lighting intensity.

14. A method as claimed in claim 13, comprising implementing a feedback loop for measuring the internal light colour temperature and intensity such that the controlling takes account of the actual internal light colour temperature and intensity as well as the desired light colour temperature and intensity.

20. A method as claimed in claim 14, wherein implementing the feedback loop includes preventing a mismatch in colour temperature at a boundary between light generated by the lighting unit and light associated with content from the outside.