Performance and color consistent LED

• US 8,096,675 B1
• Filed: 12/23/2008
• Issued: 01/17/2012
• Est. Priority Date: 12/23/2008
• Status: Active Grant

• Current Assignee: Bridgelux Incorporated
• Original Assignee: Bridgelux Incorporated
• Inventors: Posselt, Jason L.
• Primary Examiner(s): Tso, Laura
• Application Number:
  US12/343,080
• Time in Patent Office: 1,120 Days
• Field of Search: 362/230, 362/231, 362/800
• US Class Current: 362/230
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/49113 the connectors connecting different bonding areas on the semiconductor or solid-state body to a common bonding area outside the body, e.g. converging wires
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

The instant invention discloses a device and method to mix and match LED die at a LED emitter or array level in an array to obtain a consistent average weighted wavelength, and/or desired flux, reducing the spread of a color range and therefore reducing the observed LED color range. The mixing of different wavelength and flux LED'"'"'s expands the color gamut of the LEDs available to be used in a particular luminaire with a given color specification.

Claims

1. A LED array comprising;

a first color string comprising at least two first LED die emitting about a first selected wavelength, λ

_s1, and first selected range, ±

r₁, wherein the at least two first die comprise one die emitting at a wavelength shorter than the first selected wavelength, λ

_s1, minus the first selected range, r₁, and one die emitting at a wavelength longer than the first selected wavelength, λ

_s1, plus the first selected range, r₁, such that the average weighted wavelength, <

λ

_aww1>

, of the at least two first die is within λ

_s1±

r₁.

2. The LED array of claim 1 wherein said first color string has an intensity of about Φ

_w1 lumens within a range of about ±

5%.

3. The LED array of claim 1 wherein said first color string has an intensity of about Φ

_w1 lumens within a range of about ±

10%.

4. The LED array of claim 1 wherein said first color string has an intensity of about Φ

_w1 lumens within a range of about ±

15%.

5. The LED array of claim 1 wherein said first color string has an intensity of about Φ

_w1 lumens within a range of about ±

20%.

6. The LED array of claim 1 wherein the first selected range, r₁, is about ≦

1 nm.

7. The LED array of claim 1 wherein the first selected range, r₁, is about ≦

5.0 nm.

8. The LED array of claim 1 wherein the first selected range, r₁, is about ≦

7.5 nm.

9. The LED array of claim 1 wherein the first selected range, r₁, is about ≦

10 nm.

10. The LED array of claim 1 further comprising a second color string comprising at least two second LED die emitting about a second selected wavelength, λ

_s2, and second selected range, ±

r₂, wherein the at least two second die comprise one die emitting at a wavelength shorter than the second selected wavelength, λ

_s2, minus the second selected range, r₂, and one die emitting at a wavelength longer than the second selected wavelength, λ

_s2, plus the second selected range, r₂, such that the average weighted wavelength, <

λ

_aww2>

, of the at least two second die is within λ

_s2±

r₂.

11. The LED array of claim 10 wherein the second selected range, r₂, is equal to or less than a value chosen from a group comprising 1, 2.5, 5, and 10 nm.

12. The LED array of claim 10 wherein said second color string has an intensity of about Φ

_w2 lumens within a range of about ±

2.5% or within a range of about ±

5% within a range of about ±

10% or within a range of about ±

20%.

13. The LED array of claim 1 wherein said first color string is chosen from a group comprising a red string, a green string, a blue string, an amber string and a white string.

21. The LED array of claim 11 wherein said first color string emits about a first color string selected intensity, Φ

_w1 lumens within a range of ≦

±

2.5% and said second color string emits about a second color string selected intensity, Φ

_w2 lumens ≦

±

2.5%.

22. The LED array of claim 11 wherein λ

_s1 and λ

_s2 are between about 440 nm and 640 nm and said first and second ranges, r₁ and r₂, are less than or equal to about 10 nm.

14. A method for selecting die for a LED array comprising the steps:

selecting first wavelength, λ

_s1 and first range, r₁; and

selecting at least two first LED die emitting about the first wavelength wherein the at least two die comprise one die emitting at a wavelength shorter than the first wavelength minus the first range, [λ

_s1−

r₁], and one die emitting at a wavelength longer than the first wavelength plus the first range, [λ

_s1+r₁], such that the average weighted wavelength, <

λ

_aww1>

of the at least two first die satisfies;

[λ

_s1−

r₁]<

<

λ

_aww1>

<

[λ

_s1+r₁].

15. The method of claim 14 further comprising the steps:

selecting a second wavelength, λ

_s2, and a second range, r₂;

selecting at least two second LED die emitting about the second wavelength wherein the at least two second die comprise one die emitting at a wavelength less than the second wavelength, λ

_s2, minus the second range, r₂, and one die emitting at a wavelength longer than the second wavelength, λ

_s2, plus the second range, r₂, such that the average weighted wavelength, <

λ

_aww2>

of the at least two second die satisfies;

[λ

_s2−

r₂]<

<

λ

_aww2>

<

[λ

_s2+r₂].

16. The method of claim 14 further comprising the step of selecting all of said at least two first die such that said first color string emits about first nominal lumen specification, Φ

_w1, within a range of ≦

±

2.5%.

17. The method of claim 14 further comprising the step of selecting all of said at least two first die such that said first color string emits about first nominal lumen specification, Φ

_w1, within a range of ≦

±

10%.

18. The method of claim 14 further comprising the step of selecting all of said at least two first die such that said first color string emits about said first wavelength, λ

_s1 and said first range, r₁, wherein said first wavelength is a wavelength between about 440 nm and 640 nm and said first range is a range between about 1 nm and 10 nm.

19. A LED array comprising;

first and second color strings;

first and second selected wavelengths, λ

_s1, λ

_s2; and

first and second selected wavelength ranges, r₁, r₂, such that first and second color strings each comprise at least two LED die emitting about first and second wavelengths, λ

_s1, λ

_s2, wherein the at least two die of the first color string comprise one die emitting at a wavelength shorter than the first selected wavelength, λ

_s1, minus the first selected range, r₁, and one die emitting at a wavelength longer than the first selected wavelength, λ

_s1, plus the first selected range, r₁, and wherein the at least two die of the second color string comprise one die emitting at a wavelength shorter than the second selected wavelength, λ

_s2, minus the second selected range, r₂, and one die emitting at a wavelength longer than the second selected wavelength, λ

_s2, plus the second selected range, r₂, such that the average weighted wavelengths of the first color string and the second color string satisfy the requirements;

[λ

_s1−

r₁]<

<

λ

_aww1>

<

[λ

_s1+r₁] and [λ

_s2−

r₂]<

<

λ

_aww2>

<

[λ

_s2+r₂].

20. The LED array of claim 19 wherein said first color string emits about a first color string selected intensity, Φ

_w1 lumens within a range of ≦

±

2.5% and said second color string emits about a second color string selected intensity, Φ

_w2 lumens ≦

±

2.5%.

23. The LED array of claim 19 wherein Φ

_w1 and Φ

_w2 are between about 20 lm and 10,000 lm.

24. A luminaire comprising an LED array comprising at least one color string comprising at least two LED die emitting about a first selected wavelength, λ

_s1 within first selected range, r₁, wherein the at least two die of the at least one color string comprise one die emitting at a wavelength shorter than the first selected wavelength, λ

_s1, minus the first selected range, r₁, and one die emitting at a wavelength longer than the first selected wavelength, λ

_s1, plus the first selected range, r₁, such that the average weighted wavelength of the first color string satisfies the requirement;

[λ

_s1−

r₁]<

<

λ

_aww1>

<

[λ

_s1+r₁].

25. The luminaire of claim 24 wherein said average weighted wavelength, <

λ

_aww1>

, is chosen between about 440 and 640 nm and said first selected range is chosen equal to or less than about 10 nm.