IP Library Granted Patent US 7,948,172
Granted Patent B2
US 7,948,172 · App. 11/863,412 · Granted May 24, 2011

LED device having improved light output

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Quick Facts
Patent No.
US 7,948,172
App. No.
11/863,412
Granted
May 24, 2011
Kind
B2
Abstract

A thin-film, white-light-emitting diode device includes a reflective, conductive thin-film structure and a semi-transparent, conductive thin-film structure. One or more thin-film layers are formed between the reflective and semi-transparent conductive thin-film structures to form two or more commonly-controlled microcavity structures. The thin-film layers emit white light in response to current provided by the conductive thin-film structure. Each of the two or more commonly-controlled microcavity structures has a different resonant frequency within one or more optical cavities and emits light with a smaller spectral range than the spectral range of the white-light-emitting thin-film layer(s). A combination of light emitted from the two or more commonly-controlled microcavity structures is white.

Claims (26)

1. A thin-film, white-light-emitting diode device, including:

a) a reflective, conductive thin-film structure and a semitransparent, conductive thin-film structure;

b) one or more thin-film layers formed between the reflective and semi-transparent conductive thin-film structures forming only two commonly-controlled microcavity structures, the thin-film layer(s) emitting white light in response to current provided by the conductive thin-film structure;

c) wherein each of the two commonly-controlled microcavity structures has a different resonant frequency within one of the optical cavities and emits light with a smaller spectral range than the spectral range of the white-light-emitting thin-film layer(s), a combination of light emitted from the two commonly-controlled microcavity structures is white; and

d) wherein light emitted by the one of the two commonly-controlled microcavity structures is blue and light emitted by the other of the commonly-controlled microcavity structures is yellow, or light emitted by one of the commonly-controlled microcavity structures is cyan and the light emitted by the other of the commonly-controlled microcavity structures is red, or light emitted by one of the commonly-controlled microcavity structures is green and the light emitted by the other of the commonly-controlled microcavity structures is magenta.

2. The thin-film, white-light-emitting diode device of claim 1 further including one or more additional, independently-controlled structures that emit light.

3. The thin-film, white-light-emitting diode device of claim 1 further comprising color filters that filter light emitted by the white-light-emitting thin-film layer.

4. The thin-film, white-light-emitting diode device of claim 1 , wherein a color change of the combined light emitted by the two commonly-controlled microcavity structures over one or more angles is less than a color change of the light emitted by at least one of the two commonly-controlled microcavity structures over the one or more angles.

5. The thin-film, white-light-emitting diode device of claim 1 wherein the reflective, conductive thin-film structure or the semitransparent, conductive thin-film structure comprise a single layer of metal.

6. The thin-film, white-light-emitting diode device of claim 1 wherein the reflective, conductive thin-film structure includes a reflective layer and a separate transparent, conductive layer.

7. The thin-film, white-light-emitting diode device of claim 6 wherein a transparent spacer layer is located between the reflective layer and the separate transparent, conductive layer.

8. The thin-film, white-light-emitting diode device of claim 1 wherein a transparent spacer layer is located between the reflective, conductive thin-film structure and the semi-transparent, conductive thin-film structure.

9. The thin-film, white-light-emitting diode device of claim 1 further comprising two pairs of commonly-controlled microcavity structures, each pair of microcavity structures emitting light having a smaller spectral range than the spectral range of the white-light-emitting thin-film layer(s), the combination of light emitted by the pairs of commonly-controlled microcavity structures is white.

10. The thin-film, white-light-emitting diode device of claim 9 wherein light emitted by one of a pair of commonly-controlled microcavity structures is blue and light emitted by the other of the pair of commonly-controlled microcavity structures is yellow, or light emitted by one of a pair of microcavity structures is cyan and the light emitted by the other of the pair of commonly-controlled microcavity structures is red, or light emitted by one of a pair of commonly-controlled microcavity structures is green and the light emitted by the other of the pair of commonly-controlled microcavity structures is magenta.

11. The thin-film, white-light-emitting diode device of claim 10 further comprising three pairs of commonly-controlled microcavity structures, each pair producing complementary colors of light.

12. The thin-film, white-light-emitting diode device of claim 1 wherein the commonly-controlled microcavity structures are located adjacent each other over a substrate.

13. The thin-film, white-light-emitting diode device of claim 1 further comprising transparent spacer layers employed to form one or more optical cavities.

14. The thin-film, white-light-emitting diode device of claim 1 , wherein the thin-film, white-light-emitting diode device is a display device, a lamp device, or an area illumination device.

15. The thin-film, white-light-emitting diode device of claim 1 , further comprising a controller to control and provide power to the thin-film, white-light-emitting diode device.

16. A method of forming the thin-film, white-light-emitting diode device of claim 1 .

17. A thin-film, light-emitting diode device, including:

a) a reflective, conductive thin-film structure and a semi-ransparent, conductive thin-film structure;

b) one or more thin-film layers formed between the reflective and semi-transparent conductive thin-film structures forming only two commonly-controlled microcavity structures, the thin-film layer(s) emitting light in response to current provided by the conductive thin-film structures;

c) wherein each of the two commonly-controlled microcavity structures emits light having a smaller spectral range than the spectral range of the light-emitting thin-film layer(s), and a color change of the combined light emitted by the commonly-controlled microcavity structures over one or more angles is less than the color change of the light emitted by at least one of the commonly-controlled microcavity structures over the one or more angles; and

d) wherein light emitted by the one of the two commonly-controlled microcavity structures is blue and light emitted by the other of the commonly-controlled microcavity structures is yellow, or light emitted by one of the commonly-controlled microcavity structures is cyan and the light emitted by the other of the commonly-controlled microcavity structures is red, or light emitted by one of the commonly-controlled microcavity structures is green and the light emitted by the other of the commonly-controlled microcavity structures is magenta.

18. The thin-film, light-emitting diode device of claim 17 , wherein the light-emitting thin-film layer is patterned such that different light-emitting materials are employed within different commonly-controlled microcavity structures.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 11, 2010
From: EASTMAN KODAK COMPANY
To: GLOBAL OLED TECHNOLOGY LLC
Reel/Frame 024068/0468 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 28, 2007
From: COK, RONALD S.; MILLER, MICHAEL E.
To: EASTMAN KODAK COMPANY
Reel/Frame 019894/0266 →