SYSTEM AND METHOD FOR GENERATING LIGHT BY COLOR MIXING

• US 20100072900A1
• Filed: 08/29/2007
• Published: 03/25/2010
• Est. Priority Date: 09/06/2006
• Status: Abandoned Application

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Deppe, Carsten
• Application Number:
  US12/439,230
• Publication Number:
  US 20100072900A1
• Time in Patent Office: Days
• US Class Current: 315/151
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 21/2053 Intensity control of illuminating light controlled by video signal processing H04N5/74 or H04N9/31
• CPC Class Codes: G03B 21/206 Control of light source other than position or intensity
• CPC Class Codes: G03B 33/12 using beam-splitting or beam-combining systems, e.g. dichroic mirrors
• 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 45/24 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/28 using temperature feedback

Abstract

The present invention relates to a method of generating light with a predetermined chromaticity value of a color gamut by color mixing of the light emitted by a plurality of light sources, each of which emits light with a primary color, the light sources being capable of emitting light with at least three primary colors, wherein at least a first and a second light source are used to emit light of at least one primary color. The object to provide a simple method of generating light with a predetermined and constant chromaticity value of a color gamut by color mixing of the light emitted by a plurality of light sources, which can even be advantageously used in display applications sequentially displaying primary colors, is achieved in that said first and said second light source emit light with different peak and/or dominant wavelengths, the chromaticity of the primary color generated by color mixing of the light emitted from said first and said second light source being adjusted to a predetermined and constant chromaticity value by controlling the ratio of intensities of said first and said second light source, and said chromaticity value of said primary-color light generated by color mixing is used to generate light by color mixing with the light of other primary color light sources.

Claims

1. Method of generating light with a predetermined chromaticity value of a color gamut by color mixing of the light emitted by a plurality of light sources, each light source emitting light of a primary color, such the light sources are capable of emitting light with at least three primary colors, wherein at least a first and a second light source of said plurality of light sources emit light of at least one primary color, said first and said second light source emit light with different peak and/or dominant wavelengths, wherein the chromaticity of the primary color generated by color mixing of the light emitted from said first and said second light source is adjusted to a predetermined chromaticity value through a control of the ratio of intensities of said first and said second light source, and said chromaticity value of said primary-color light generated by color mixing is used to generate light by color mixing with the light of other primary-color light sources, wherein the chromaticity value of at least one primary-color light is calculated from intensity measurements by at least one light sensor for said first and said second light source based at least in part on constant chromaticity values for the respective light sources, the intensity of each light source being measured within a predetermined time slot.

2. Method according to claim 1, wherein the chromaticity value at least of one of the primary colors is adjusted to a chromaticity value with a higher efficiency with respect to the human eye by means of the ratio of the intensities of the dedicated light sources.

3. Method according to claim 1, wherein the light sources are LEDs.

5. Method according claim 1, wherein at least one wavelength-sensitive light sensor is used to determine the chromaticity value of one light of the primary color, wherein at least two wavelength-sensitive light sensors comprising different color filters are used to determine the chromaticity value of one light of the primary color.

6. Method according claim 1, wherein currents, voltages, and/or duty factors of at least said first and said second light source are controlled by a microcontroller to achieve a predetermined chromaticity value of the respective primary-color light.

7. Method according to claim 6, wherein the microcontroller comprises a memory for storing control values at least of said first and said second light source.

8. Method according to claim 7, wherein control values of each light source used to generate primary-color light are stored in a look-up table in the memory.

10. Method according to claim 1, wherein the intensities of the light sources are controlled through amplitude modulation (AM) of the driving current or voltage of the light sources.

4. (canceled)

9. (canceled)

11-16. -16. (canceled)