Method and apparatus for setting a chromaticity coordinate

• US 20120068610A1
• Filed: 05/11/2010
• Published: 03/22/2012
• Est. Priority Date: 05/19/2009
• Status: Active Grant

• Current Assignee: Optotronic GmbH (Inventronics (Hangzhou), Inc.)
• Original Assignee: OSRAM Licht AG (Ams-Osram AG)
• Inventors: Bertram, Ralph
• Granted Patent: US 8,604,702 B2
• Time in Patent Office: Days
• US Class Current: 315/152
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/22 using optical feedback

Abstract

A method for setting a color locus of a luminaire (110) comprising at least one phosphor-converted light-emitting diode (103, 105) and at least one monochromatic light-emitting diode (104), wherein the method comprises the steps of: setting a current for the at least one phosphor-converted light-emitting diode (103, 105) setting a pulse width modulation for the at least one phosphor-converted light-emitting diode (104); and setting a current or a pulse width modulation for the at least one monochromatic light-emitting diode (104).

Claims

1. A method for setting a color locus of a luminaire comprising at least one phosphor-converted light-emitting diode and at least one monochromatic light-emitting diode, wherein the method comprises the steps of:

setting a current for the at least one phosphor-converted light-emitting diode;

setting a pulse width modulation for the at least one phosphor-converted light-emitting diode; and

setting a current or a pulse width modulation for the at least one monochromatic light-emitting diode.

2. The method as claimed in claim 1, wherein the color locus is set depending on a setpoint color locus.

3. The method as claimed in claim 2, wherein an actual value is identified by the at least one sensor, wherein a discrepancy between the actual value and the setpoint color locus is determined and the color locus is set correspondingly in such a way that the setpoint color locus is achieved.

4. The method as claimed in claim 3, wherein the at least one sensor comprises a temperature sensor and/or an optical sensor.

5. The method as claimed in claim 3, wherein the actual value is determined in accordance with a CIE CxCy color space,

in accordance with a CIE uv color space,

in accordance with a CIE u′

v′

color space and/or

in accordance with a tristimulus XYZ space.

6. The method as claimed in claim 3, wherein the actual value is converted into the following regulation parameters for setting the color locus:

the current for the at least one phosphor-converted light-emitting diode; and

the pulse width modulation for the at least one phosphor-converted light-emitting diode;

the current for the at least one monochromatic light-emitting diode.

7. The method as claimed in claim 3, wherein the actual value is converted into the following regulation parameters for setting the color locus:

the current for the at least one phosphor-converted light-emitting diode; and

the pulse width modulation for the at least one phosphor-converted light-emitting diode; and

the pulse width modulation for the at least one monochromatic light-emitting diode.

8. The method as claimed in claim 1, wherein the color locus is set by a lookup table.

9. The method as claimed in claim 1, wherein the phosphor-converted light-emitting diode emits light in at least one of the following colors:

white light,

violet light,

greenish light,

reddish light.

10. The method as claimed in claim 1, wherein the monochromatic light-emitting diode is a red light-emitting diode.

14. The method as claimed in claim 1, wherein the color locus is set depending on a threshold value around the setpoint color locus.

11. An apparatus for setting a color locus of a lamp or luminaire comprising at least one phosphor-converted light-emitting diode and at least one monochromatic light-emitting diode,

with a control unit, which detects a brightness and/or a temperature of the light-emitting diodes via at least one sensor and drives a driver in such a way that:

a current can be set for the at least one phosphor-converted light-emitting diode; and

a pulse width modulation can be set for the at least one phosphor-converted light-emitting diode;

a current or a pulse width modulation can be set for the at least one monochromatic light-emitting diode.

12. The apparatus as claimed in claim 11, wherein the control unit comprises a microcontroller or a processor.

13. A lamp or luminaire comprising the apparatus as claimed in claim 11.