METHOD AND APPARATUS FOR CONTROLLING AND MEASURING ASPECTS OF TIME-VARYING COMBINED LIGHT

• US 20110156596A1
• Filed: 08/24/2009
• Published: 06/30/2011
• Est. Priority Date: 09/08/2008
• Status: Active Grant

• Current Assignee: Philips Lighting BV (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Salsbury, Marc
• Granted Patent: US 8,664,864 B2
• Time in Patent Office: Days
• US Class Current: 315/152
• CPC Class Codes: H05B 45/22 using optical feedback

Abstract

Methods and apparatus are disclosed for providing combined time-varying light comprising light from one or more light sources (132, 134, 136), and determining aspects of light from one or more light sources based on measurements of the combined light. Light sources of one or more colours can be controlled to provide time-varying combined light outputs (310, 360) using different switching sequences for different light sources, for example according to PWM, PCM, or other modulation methods. By appropriately configuring the timing of the switching sequences, the combined light output can be made to exhibit a plurality of lighting combinations. A broadband optical sensor (148) can be configured to measure (145) some or all of the plurality of lighting combinations, and the measurements used to determine light output measurements of portions of the combined light, and optionally of ambient light, by appropriate processing (150) of the measurements.

Claims

1. An apparatus for controlling and measuring light, the apparatus comprising:

a. a controller module (110) operatively coupled to two or more light sources (132, 134, 136), the controller module configured to generate two or more switching sequences, each switching sequence for controlling operation of one of the light sources, the two or more switching sequences configured to result in generation of a desired lighting effect and two or more different measurable combinations of light, at least one measurable combination comprising light from one or more of the light sources;

b. a light measurement module (145) operatively coupled to the controller module and configured to receive signals indicative of the switching sequences, the light measurement module configured to define one or more measurement sequences based on the switching sequences, the light measurement module configured to provide one or more light measurements based on the measurement sequences; and

c. a processing module (150) operatively coupled to the light measurement module and the controller module, the processing module configured to determine an indication of light output by at least one of the two or more light sources based at least in part on the one or more light measurements and the two of more switching sequences.

2. The apparatus according to claim 1, wherein the controller module is further configured to provide each of the two or more different measurable combinations of light for at least a predetermined minimum amount of time.

3. The apparatus according to claim 1, wherein the controller module is further configured to adjust the two or more switching sequences, based on the indication of light output by at least one of the two or more light sources, to facilitate generation of the desired lighting effect.

4. The apparatus according to claim 1, wherein the processing module is further configured to determine an indication of ambient light.

5. The apparatus according to claim 1, wherein the processing module is configured to determine the indication of light output by solving a linear system of equations.

6. The apparatus according to claim 1, wherein the processing module is further configured to determine whether the provided one or more light measurements are sufficient for determining one or more desired indications of light output.

7. The apparatus according to claim 6, wherein the processing module is further configured to provide an indication to the controller module and/or the measurement module regarding whether the provided one or more light measurements are sufficient for determining one or more desired indications of light output.

8. A method for controlling and measuring light comprising light generated by two or more light sources, the method comprising the steps of:

a. providing two or more switching sequences, each switching sequence for controlling operation of one of the light sources, the two or more switching sequences configured to result in generation of a desired lighting effect and two or more different measurable combinations of light, at least one measurable combination comprising light from one or more of the light sources;

b. providing one or more measurement sequences based on the switching sequences;

c. providing one or more light measurements based on the measurement sequences; and

d. processing the one or more light measurements to determine an indication of light output by at least one of the two or more light sources based at least in part on the one or more light measurements and the two or more switching sequences.

9. The method according to claim 8, wherein each of the two or more different measurable combinations of light are provided for at least a predetermined minimum amount of time.

10. The method according to claim 9, further comprising the steps of:

a. determining whether each of the two or more different measurable combinations of light are provided for at least the predetermined minimum amount of time; and

b. adjusting the two or more switching sequences if at least one of the two or more different measurable combinations of light is determined to be provided for less than the predetermined minimum amount of time.

11. The method according to claim 8, further comprising the step of adjusting the two or more switching sequences, based on the indication of light output by at least one of the two or more light sources, to facilitate generation of the desired lighting effect.

12. The method according to claim 8, wherein processing of the one or more light measurements includes determining an indication of ambient light.

13. The method according to claim 8, wherein determining an indication of light output comprises solving a linear system of equations.

14. The method according to claim 8, further comprising the steps of:

a. determining whether the provided one or more light measurements are sufficient for determining one or more desired indications of light output; and

b. adjusting the two or more switching sequences if the provided one or more light measurements are determined to be insufficient for determining one or more desired indications of light output.

15. A computer program product comprising a computer readable medium having recorded thereon statements and instructions for execution by a processor to carry out a method for controlling and measuring light comprising light generated by two or more light sources, the method comprising the steps of:

a. providing two or more switching sequences, each switching sequence for controlling operation of one of the light sources, the two or more switching sequences configured to result in generation of a desired lighting effect and two or more different measurable combinations of light, at least one measurable combination comprising light from one or more of the light sources;

b. providing one or more measurement sequences based on the switching sequences;

c. providing one or more light measurements based on the measurement sequences; and

d. processing the one or more light measurements to determine an indication of light output by at least one of the two or more light sources based at least in part on the one or more light measurements and the two or more switching sequences.