Control system for an illumination device incorporating discrete light sources

• US 7,140,752 B2
• Filed: 07/22/2004
• Issued: 11/28/2006
• Est. Priority Date: 07/23/2003
• Status: Expired due to Term

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: TIR Systems Limited (Koninklijke Philips N.V.)
• Inventors: Ashdown, Ian
• Primary Examiner(s): Luebke, Renee
• Assistant Examiner(s): Shallenberger, Julie A.
• Application Number:
  US10/897,990
• Publication Number:
  US 20050062446A1
• Time in Patent Office: 859 Days
• Field of Search: None
• US Class Current: 362/276
• 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 45/28 using temperature feedback
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

The present invention provides an illumination system enabling dynamic color control of the illumination produced by the system. The illumination system comprises light-emitting elements for producing illumination, and at least one detecting device which collects information relating to the illumination, which is inherently non-linear. The illumination system also integrates a computing system which receives the information from the at least one detecting device and linearises this information using a multivariate function having a solution defining a hyperplane representing constant chromaticity for a given luminous intensity, and then determines a number of control parameters based on the information. The illumination system also integrates a controller for receiving the control parameters from the computing system and determining the control signals to be sent to the light-emitting elements in order to dynamically alter the characteristics of the illumination based on the collected information and the desired illumination result.

Claims

1. An illumination system comprising:

a) a plurality of light-emitting elements for providing illumination having a variety of wavelengths,

b) at least one detecting device for providing information regarding the illumination being created by the light-emitting elements;

c) a computing system for receiving the information from the at least one detecting device and based on a predetermined set of parameters, determining a plurality of control parameters, said predetermined set of parameters defined by a multivariate function having a solution defining a hyperplane representing constant chromaticity for a given luminous intensity;

d) a controller for receiving the plurality of control parameters and determining a set of control signals, wherein said control signals are sent to the light-emitting elements in order to control the illumination being created; and

e) a power source for providing power to the illumination system.

2. The illumination system according to claim 1, wherein the at least one detecting device is capable of collecting information representing characteristics selected from the group comprising luminous and spectral radiant flux of the illumination, junction temperature of at least one of the plurality of light-emitting elements, desired luminous intensity, correlated colour temperature and ambient light.

3. The illumination system according to claim 1, wherein the at least one detecting device is a photometric sensor or a colourmetric sensor.

4. The illumination system according to claim 1, wherein the computing device is a microcontroller.

5. The illumination system according to claim 1, wherein a neural network is integrated into the computing system.

6. The illumination system according to claim 5, wherein the neural network is a radial basis function.

7. The illumination system according to claim 5, wherein the neural network is a generalised radial basis function.

8. The illumination system according to claim 1, wherein the controller is a proportional integral-derivative controller.

9. The illumination system according to claim 1, wherein controller functionality is integrated into the computing system.

10. The illumination system according to claim 1, wherein the plurality of light-emitting elements are arranged in one or more arrays.

11. The illumination system according to claim 10, wherein each of the one or more arrays are individually controlled by the controller.

12. The illumination system according to claim 1, wherein the plurality of light emitting elements are individually controlled by the controller.