METHOD AND DEVICE FOR MODULATING THE LIGHT EMISSION OF A LIGHTING DEVICE

• US 20090196613A1
• Filed: 06/18/2007
• Published: 08/06/2009
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Linnartz, Johan Paul Marie Gerard
• Granted Patent: US 8,494,367 B2
• Time in Patent Office: Days
• US Class Current: 398/78
• CPC Class Codes: H04B 10/11 Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
• CPC Class Codes: H05B 45/22 using optical feedback

Abstract

The invention relates to controlling a lighting device, particularly to the modulation of light generated by a solid state lighting (SSL) device. The invention provides a method and device for modulating the light emission of a lighting device by keying each pulse (14) of a sequence of pulses (16) contained in the control signal (10) according to a spreading code. Thus, the light emission of a lighting device may be identified by detecting the spreading code used for modulating the light emission. The invention is particularly suitable for lighting means containing several lighting devices such as a LED lighting board with dozens of LEDs since the light emission of each lighting device may be detected by the spreading code used for modulating the light emission.

Claims

1. A computer-executable method for modulating the light emission of a lighting device, the method comprising:

generating a control signal for controlling the light emission of the lighting device, the control signal comprising a plurality of frames of an equal time duration, at least one frame including a pulse for switching the lighting device on or off, and keyed according to a spreading code for modulating the light emission of the lighting device.

2. The method of claim 1, wherein a predetermined starting position within the at least one frame is assigned to the pulse.

3. The method of claim 1, wherein Pulse Position Modulation (PPM) or On-Off Keying (OOK) is applied as modulation scheme to one or more pulses of the control signal.

4. The method of claim 3, wherein for applying OOK a pulse comprises a first part provided for OOK keying and a second part provided for controlling the illumination of the lighting device.

5. The method of claim 3, wherein for applying PPM the position of the beginning of a pulse within a frame is selected depending on the keying.

6. The method according to claim 1, wherein the average pulse width is chosen such that a desired illumination is achieved.

7. The method according to claim 1, wherein the light emission of several lighting devices is modulated by generating a control signal for each of the lighting devices and assigning to each control signal an unique spreading code.

8. The method of claim 7, wherein the starting positions of pulses within the frames of at least one first control signal differ from the starting positions of pulses within the frames of at least one second control signal.

12. A method for generating an adaptive illumination with at least one lighting device, wherein the light emission of the at least one lighting device is modulated according to claim 1 and the illumination is adapted by detecting the light emitted by the at least one lighting device by means of the spreading code assigned to the lighting device and to modulate the light emission depending on the detected light and according to a predefined control algorithm.

9-11. -11. (canceled)

13-17. -17. (canceled)