HIGH EFFICACY LIGHTING SIGNAL CONVERTER AND ASSOCIATED METHODS

• US 20120286700A1
• Filed: 05/15/2011
• Published: 11/15/2012
• Est. Priority Date: 05/15/2011
• Status: Active Grant

• Current Assignee: Lighting Science Group Corporation (Pegasus Capital Advisors, L.P.)
• Original Assignee: Lighting Science Group Corporation (Pegasus Capital Advisors, L.P.)
• Inventors: Maxik, Fredric S., Soler, Robert R., Bartine, David E., Zhou, Ran, Bastien, Valerie A., Grove, Eliza Katar, Regan, Matthew
• Granted Patent: US 8,547,391 B2
• Time in Patent Office: Days
• US Class Current: 315/312
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

A signal adapting chromacity system to control that may include a signal conversion engine to receive a source signal designating a color of light defined by a two spatial plus luminance dimensional color space, such as the xxY color space. The signal conversion engine may convert the source signal to a three dimensional color space defined within a subset gamut of a full color gamut, such as an RGW, RBW, or GBW color space. The subset gamut may include a first color light, a second color light and a high efficacy light. The signal conversion engine may perform a conversion operation to convert the source signal to an output signal, using the output signal to drive light emitting diodes (LEDs). The conversion operation may be a matrix, angular or linear conversion operation.

Claims

1. A signal adapting chromacity system to control a lighting device comprising:

a signal conversion engine that receives a source signal designating a color of light defined by a two spatial plus luminance dimensional color space and converts the source signal to a three dimensional color space defined within a subset gamut of a full color gamut;

wherein the signal conversion engine performs a conversion operation to convert the source signal to an output signal, and uses the output signal to drive light emitting diodes (LEDs); and

wherein the subset gamut includes a first color light, a second color light and a high efficacy light.

2. A system according to claim 1 wherein the first color light and the second color light are emitted by colored LEDs, and wherein the high efficacy light is emitted by a high efficacy LED.

3. A system according to claim 2 further including a conversion coating applied to the colored LEDs to convert a source light wavelength range into a converted light wavelength range.

4. A system according to claim 1 wherein the two spatial plus luminance dimensional color space is a xyY color space, the three dimensional color space defined within the full color gamut is a RGBW color space, and the three dimensional color space defined within the subset gamut is selected from a group comprising a RGW color space, GBW color space, or RBW color space.

5. A system according to claim 1 wherein the first color light and the second color light are selected from a group comprising a red light, a blue light, and a green light, and wherein the high efficacy light is a white light.

6. A system according to claim 1 wherein the high efficacy light is defined by a color temperature between 2000K and 10000K.

7. A system according to claim 1 wherein the conversion operation converts the source signal to the output signal by performing a matrix conversion operation.

8. A system according to claim 7 wherein matrices are defined for the two spatial plus luminance dimensional color space included in the source signal;

wherein the matrices are inverted to define inverse matrices that are processed to define a scalar including scalar values that are positive and included in the output signal; and

wherein the output signal defines the color of the light in the three dimensional color space defined within the subset gamut.

9. A system according to claim 7 wherein the matrices that are defined as non-square matrices undergo square matrix preconditioning.

10. A system according to claim 1 wherein the conversion operation converts the source signal to the output signal by performing an angular conversion operation.

11. A system according to claim 10 wherein the three dimensional color space defined by the subset gamut is divided from the full color gamut by using angular determination, the subset gamut including

an origin that includes the high efficacy light,

primaries that include colored light, the primaries defined in the subset gamut including a first subset primary relative to the first color light and a second subset primary relative to the second color light, and

a subset gamut angular range included between a first primary angle relative to the first subset primary and a second primary angle relative to the second primary angle.

12. A system according to claim 11 wherein the three dimensional color space included in the subset gamut is triangularly located between the origin, the first subset primary, and the second subset primary;

wherein the color of the light defined by the two spatial plus luminance dimensional color space is plotted in the three dimensional color space of the full color gamut; and

wherein a color angle is located within the three dimensional color space defined by the subset gamut relative to the color of the light, the color angle being located between the first primary angle and the second primary angle.

13. A system according to claim 12 wherein a first primary angular range is included between the first primary angle and the color angle, and wherein a second primary angular range is included between the second primary angle and the color angle;

wherein the first primary angular range is compared to the second primary angular range to determine a first primary angular ratio proportional to a first portion of the subset gamut angular range comprised of the first primary angular range, and the first primary angular ratio determining a luminosity of the first subset primary included in the output signal;

wherein the second primary angular range is compared to the first primary angular range to determine a second primary angular ratio proportional to a second portion of the subset gamut angular range comprised of the second primary angular range, and the second primary angular ratio determining the luminosity of the second subset primary included in the output signal; and

wherein the luminosity of the first subset primary and second subset primary are analyzed to determine the luminosity of the high efficacy light included in the output signal.

14. A system according to claim 1 wherein the conversion operation converts the source signal to the output signal by performing a linear conversion operation.

15. A system according to claim 14 wherein the three dimensional color space defined by the subset gamut is divided from the full color gamut to include

an origin that includes the high efficacy light,

primaries that include colored light, the primaries defined in the subset gamuts including a first subset primary relative to the first color light and a second subset primary relative to the second color light, and

a color point defined by plotting the color of the light as defined within the two spatial plus luminance dimensional color space in the three dimensional color space of the full color gamut;

and

wherein lines are defined relative to the two spatial plus luminance dimensional color space.

16. A system according to claim 15 wherein the lines include

a first primary line defined between the origin and the first subset primary,

a second primary line defined between the origin and the second subset primary,

a color line defined between origin and the color point including a slope and an axial intercept, and

a subset gamut line that intersects the first primary line, the second primary line, and the color point.

17. A system according to claim 16 wherein the axial intercept is located at the origin;

wherein the subset gamut line interests the first primary line at a first primary intersection distance from the origin, wherein the subset gamut line intersects the second primary line at a second primary intersection distance from the origin, and wherein the first primary intersection distance and the second primary intersection distance are substantially equal;

wherein a subset gamut linear range is defined along the subset gamut line between the first primary line and the second primary line, the subset gamut linear range including a first primary linear range and a second primary linear range;

wherein the first primary linear range is compared to the second primary linear range to determine a first primary linear ratio proportional to a first portion of the subset gamut linear range comprised of the first primary linear range, and the first primary linear ratio determining a luminosity of the first subset primary included in the output signal;

wherein the second primary linear range is compared to the first primary linear range to determine a second primary linear ratio proportional to a second portion of the subset gamut linear range comprised of the second primary linear range, and the second primary linear ratio determining the luminosity of the second subset primary included in the output signal; and

wherein the luminosity of the first subset primary and the second subset primary are analyzed to determine the desired luminosity of the high efficacy light included in the output signal.

18. A system according to claim 1 wherein a color feedback signal is received to perform a color correction operation.

19. A method for controlling a lighting device comprising:

receiving a source signal designating a color of light defined by a two spatial plus luminance dimensional color space;

converting the source signal to an output signal defined by a three dimensional color space defined within a subset gamut of a full color gamut by performing a conversion operation, the subset gamut including a first color light, a second color light and a high efficacy light; and

using the output signal to drive light emitting diodes (LEDs).

20. A method according to claim 19 wherein the first color light and the second color light are emitted by colored LEDs, and wherein the high efficacy light is emitted by a high efficacy LED.

21. A method according to claim 20 further including converting a source light wavelength range into a converted light wavelength range by applying a conversion coating to the colored LEDs.

22. A method according to claim 19 wherein the two spatial plus luminance dimensional color space is a xyY color space, the three dimensional color space defined within the full color gamut is a RGBW color space, and the three dimensional color space defined within the subset gamut is selected from a group comprising a RGW color space, GBW color space, or RBW color space.

23. A method according to claim 19 further including selecting the first color light and the second color light from a group comprising a red light, a blue light, and a green light, and wherein the high efficacy light is a white light.

24. A method according to claim 19 wherein the high efficacy light is defined by a color temperature between 2000K and 10000K.

25. A method according to claim 19 further including performing a matrix conversion operation to convert the source signal to the output signal.

26. A method according to claim 25 wherein performing the matrix conversion operation further includes defining matrices for the two spatial plus luminance dimensional color space included in the source signal;

inverting the matrices to define inverse matrices;

processing the inverse matrices to define a scalar including scalar values that are positive and included in the output signal; and

defining the color of the light in the three dimensional color space defined within the subset gamut in the output signal.

27. A method according to claim 25 further including preconditioning the matrices that are defined as non-square matrices.

28. A method according to claim 19 further including performing an angular conversion operation to convert the source signal to the output signal.

29. A method according to claim 28 wherein performing the angular conversion operation further includes dividing three dimensional color space defined by the full color gamut by using angular determination to include the three dimensional color space defined by the subset gamut by including

an origin that includes the high efficacy light,

primaries that include colored light, the primaries defined in the subset gamut including a first subset primary relative to the first color light and a second subset primary relative to the second color light, and

a subset gamut angular range included between a first primary angle relative to the first subset primary and a second primary angle relative to the second primary angle.

30. A method according to claim 29 wherein performing the angular conversion operation further includes triangularly locating the three dimensional color space included in the subset gamut between the origin, the first subset primary, and the second subset primary;

plotting the color of the light defined by two spatial plus luminance dimensional color space in the three dimensional color space of the full color gamut; and

locating a color angle within the three dimensional color space defined by the subset gamut relative to the color of the light, the color angle being located between the first primary angle and the second primary angle.

31. A method according to claim 30 wherein performing the angular conversion operation further includes locating a first primary angular range between the first primary angle and the color angle;

locating a second primary angular range between the second primary angle and the color angle;

comparing the first primary angular range to the second primary angular range to determine a first primary angular ratio proportional to a first portion of the subset gamut angular range comprised of the first primary angular range, and the first primary angular ratio determining a luminosity of the first subset primary included in the output signal;

comparing the second primary angular range to the first primary angular range to determine a second primary angular ratio proportional to a second portion of the subset gamut angular range comprised of the second primary angular range, and the second primary angular ratio determining the luminosity of the second subset primary included in the output signal; and

analyzing the luminosity of the first subset primary and second subset primary to determine the luminosity of the high efficacy light included in the output signal.

32. A method according to claim 19 further including performing a linear conversion operation to convert the source signal to the output signal.

33. A method according to claim 32 wherein performing the linear conversion operation further includes dividing the three dimensional color space defined by the full color gamut to include the three dimensional color space defined by the subset gamut by including

an origin that includes the high efficacy light,

primaries that include colored light, the primaries defined in the subset gamuts including a first subset primary relative to the first color light and a second subset primary relative to the second color light, and

a color point defined by plotting the color of the light as defined within the two spatial plus luminance dimensional color space in the three dimensional color space of the full color gamut;

and

defining lines relative to the two spatial plus luminance dimensional color space.

34. A method according to claim 33 wherein the lines include

a first primary line defined between the origin and the first subset primary,

a second primary line defined between the origin and the second subset primary,

a color line defined between origin and the color point including a slope and an axial intercept, and

a subset gamut line that intersects the first primary line, the second primary line, and the color point.

35. A method according to claim 34 wherein performing the linear conversion operation further includes locating the axial intercept at the origin;

wherein the subset gamut line interests the first primary line at a first primary intersection distance from the origin, wherein the subset gamut line intersects the second primary line at a second primary intersection distance from the origin, and wherein the first primary intersection distance and the second primary intersection distance are substantially equal;

defining a subset gamut linear range along the subset gamut line between the first primary line and the second primary line, the subset gamut linear range including a first primary linear range and a second primary linear range;

comparing the first primary linear range to the second primary linear range to determine a first primary linear ratio proportional to a first portion of the subset gamut linear range comprised of the first primary linear range, and the first primary linear ratio determining a luminosity of the first subset primary included in the output signal;

comparing the second primary linear range to the first primary linear range to determine a second primary linear ratio proportional to a second portion of the subset gamut linear range comprised of the second primary linear range, and the second primary linear ratio determining the luminosity of the second subset primary included in the output signal; and

analyzing the luminosity of the first subset primary and the second subset primary to determine the desired luminosity of the high efficacy light included in the output signal.

36. A method according to claim 19 further including receiving a color feedback signal and performing a color correction operation.