Semiconductor light emitting devices having selectable and/or adjustable color points and related methods
First Claim
Patent Images
1. A semiconductor light emitting device, comprising:
- a first string of first light emitting diodes (“
LED”
) that emit unsaturated light having a color point that is within at least eight MacAdam ellipses from one or more points within a first region on the 1931 CIE Chromaticity Diagram defined by x, y chromaticity coordinates (0.32, 0.40), (0.36, 0.48), (0.43, 0.45), (0.42, 0.42), (0.36, 0.38), (0.32, 0.40);
a second string of second LEDs that emit unsaturated light having color point that is within at least eight MacAdam ellipses from one or more points within a second region on the 1931 CIE Chromaticity Diagram defined by x, y chromaticity coordinates (0.35, 0.48), (0.26, 0.50), (0.13, 0.26), (0.15, 0.20), (0.26, 0.28), (0.35, 0.48);
a third light source that emits radiation having a dominant wavelength between 600 and 720 nm; and
a drive circuit that is configured to provide a first drive current to the first string of LEDs, a second drive current to the second string of LEDs and a third drive current to the third light source, wherein at least two of the first, second and third drive currents are configured to be independently controlled.
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Abstract
Light emitting devices include a first string of LEDs that emit light having a color point that is within at least eight MacAdam ellipses of a first blue-shifted-yellow region on the 1931 CIE Chromaticity Diagram, a second string of LEDs that emit light having color point that is within at least eight MacAdam ellipses of a second blue-shifted-green region on the 1931 CIE Chromaticity Diagram, and a third light source that emits radiation having a dominant wavelength between 600 and 720 nm. A drive circuit supplies respective drive currents to the first string of LEDs, the second string of LEDs and the third light source, at least two of which are independently controllable.
86 Citations
29 Claims
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1. A semiconductor light emitting device, comprising:
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a first string of first light emitting diodes (“
LED”
) that emit unsaturated light having a color point that is within at least eight MacAdam ellipses from one or more points within a first region on the 1931 CIE Chromaticity Diagram defined by x, y chromaticity coordinates (0.32, 0.40), (0.36, 0.48), (0.43, 0.45), (0.42, 0.42), (0.36, 0.38), (0.32, 0.40);a second string of second LEDs that emit unsaturated light having color point that is within at least eight MacAdam ellipses from one or more points within a second region on the 1931 CIE Chromaticity Diagram defined by x, y chromaticity coordinates (0.35, 0.48), (0.26, 0.50), (0.13, 0.26), (0.15, 0.20), (0.26, 0.28), (0.35, 0.48); a third light source that emits radiation having a dominant wavelength between 600 and 720 nm; and a drive circuit that is configured to provide a first drive current to the first string of LEDs, a second drive current to the second string of LEDs and a third drive current to the third light source, wherein at least two of the first, second and third drive currents are configured to be independently controlled. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A light emitting device, comprising:
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a first light emitting diode (“
LED”
) string that includes a first LED that has a first recipient luminophoric medium that includes a first luminescent material that emits light having a peak wavelength within the green color range in response to radiation emitted by the first LED;a second LED string that includes a second LED that has a second recipient luminophoric medium that includes a second luminescent material that emits light having a peak wavelength within the yellow color range in response to radiation emitted by the second LED; a third LED string that includes a third LED that emits light having a distinct spectral peak within the red or orange color range; and a drive circuit that is configured to provide first, second and third drive currents to the respective first, second and third LED strings, wherein at least two of the first, second and third drive currents are independent of each other. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A semiconductor light emitting device, comprising:
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a first light emitting diode (“
LED”
) string that includes at least one first type of LED;a second LED string that includes at least one second type of LED; a third LED string that includes at least one third type of LED; and a circuit that allows an end user of the semiconductor light emitting device to adjust the relative values of the drive current provided to the LEDs in the first and second LED strings to adjust a color point of the light emitted by the semiconductor light emitting device, wherein the first LED string emits radiation having a first color point on the 1931 CIE Chromaticity Diagram and the second LED string emits radiation having a second color point on the 1931 CIE Chromaticity Diagram, wherein the first and second color points define a line that is generally parallel to points on the black body locus that fall between 3000K and 10,000K.
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23. A light emitting device, comprising:
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a first light emitting diode (“
LED”
) string that includes a first LED that has a recipient luminophoric medium that includes a first luminescent material that emits light having a peak wavelength within the green color range and a second LED that has a recipient luminophoric medium that includes a second luminescent material that emits light having a peak wavelength within the yellow color range;a second LED string that includes at least one LED that emits light having a peak wavelength within the red color range; and a drive circuit that is configured to provide first drive current to the first LED string and a second drive current that is independent of the first drive current to the second LED string. - View Dependent Claims (24, 25, 26, 27, 28, 29)
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Specification