Dimmable light source

Patent metadata

Field	Value
Publication number	US-11230664-B2
Application number	US-201816637282-A
Country	US
Kind code	B2
Filing date	Feb 12, 2018
Priority date	Nov 11, 2016
Publication date	Jan 25, 2022
Grant date	Jan 25, 2022

Abstract

A dimmable light source for emitting white overall radiation may include a dimmer and a light-emitting diode. The dimmer may vary a current intensity of a current for operating the light-emitting diode during the operation of the light source. The LED may include a semiconductor layer sequence to emit primary radiation, and the LED may further include a conversion element configured to at least partially convert the primary radiation into secondary radiation having a first emission band with a first emission maximum ranging from 400 nm to 500 nm and a second emission band with a second emission maximum ranging from 510 nm to 700 nm. A relative intensity of the first emission band may reduce with decreasing current intensity of the current for operating the LED, and a relative intensity of the second emission band may increase with decreasing current intensity of the current for operating the LED.

First claim

The invention claimed is:

1. A dimmable light source for emitting white overall radiation, wherein the light source comprises:
a dimmer; and
two or more of the same light-emitting diodes,
wherein:
the dimmer is configured to vary a current intensity of a current for operating the two or more of the same light-emitting diodes during the operation of the light source; and
each light-emitting diode of the two or more of the same light-emitting diodes comprises:
a semiconductor layer sequence configured to emit primary electromagnetic radiation in the UV range of the electromagnetic spectrum during the operation of the light source; and
a conversion element, comprising a converter material configured to at least partially convert, the primary electromagnetic radiation into secondary electromagnetic radiation, having a first emission band with a first emission maximum ranging from 400 nm to 500 nm and a second emission band with a second emission maximum of ranging from 510 nm to 700 nm; and wherein a relative intensity of the first emission band reduces with decreasing current intensity of the current for operating the two or more of the same light-emitting diodes, and a relative intensity of the second emission band increases with decreasing current intensity of the current for operating the two or more of the same light-emitting diodes; wherein the converter material comprises a first phosphor with the formula (MA)Si 2 O 2 N 2 :Eu with MA=Sr, Ca and/or Ba, and a second phosphor with the formula CaLu 2 Mg 2 Si 3 O 12 :Ce.

2. The dimmable light source as claimed in claim 1 , wherein the converter material is configured to convert the primary electromagnetic radiation into the secondary electromagnetic radiation in full; and wherein the white overall radiation completely, corresponds to the secondary radiation.

3. The dimmable light source as claimed in claim 1 , wherein a temperature of the converter material reduces with decreasing current intensity of the current for operating the two or more of the same light-emitting diodes.

4. The dimmable light source as claimed in claim 1 , wherein the overall radiation has a correlated color temperature, which reduces with decreasing current intensity of the current for operating the two or more of the same light-emitting diodes.

5. The dimmable light source as claimed in claim 1 , wherein the primary electromagnetic radiation has a wavelength ranging from 300 nm to 420 nm.

6. The dimmable light source as claimed in claim 1 , wherein the converter material consists of the first phosphor with the formula (MA)Si 2 O 2 N 2 :Eu and the second phosphor with the formula CaLu 2 Mg 2 Si 3 O 12 :Ce.

7. The dimmable light source as claimed in claim 6 , wherein the first phosphor has the formula (Sr x Ba 1-x )Si 2 O 2 N 2 :Eu with 0≤x≤0.5.

8. The dimmable light source as claimed in claim 6 , wherein the first phosphor has the formula (Sr x Ba 1-x )Si 2 O 2 N 2 :Eu with x=0.25.

9. The dimmable light source as claimed in claim 1 , wherein the first phosphor has the formula (Sr x Ba 1-x )Si 2 O 2 N 2 :Eu with 0≤x≤1.

10. The dimmable light source as claimed in claim 1 , wherein the dimmer is a single dimmer.

11. The dimmable light source as claimed in claim 1 , wherein the dimmer is configured to actuate the two or more of the same light-emitting diodes together.

Assignees

• Osram Oled Gmbh

Inventors

• Baumann Dominik
• Lange Stefan

Classifications

• C09K11/77742

  Silicates · CPC title

• C09K11/77347

  Silicon Nitrides or Silicon Oxynitrides · CPC title

• C09K11/77342

  Silicates · CPC title

• H10H20/8513

  having two or more wavelength conversion materials · CPC title

• H10H20/8512

  Wavelength conversion materials · CPC title