White light emitting module

Patent metadata

Field	Value
Publication number	US-10090442-B2
Application number	US-201314390439-A
Country	US
Kind code	B2
Filing date	Apr 4, 2013
Priority date	Apr 6, 2012
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A light emitting module ( 10 ), adapted to produce white output light having an emission peak in the wavelength range from 400 to 440 nm, comprises: ⋅—at least one first light emitting element ( 110 ) adapted to emit light having an emission peak in a first wavelength range from 440 to 460 nm; ⋅—at least one wavelength converting material ( 85 ) arranged to receive light emitted by said first light emitting element, and being capable of emitting light having an emission peak in the green to red wavelength range; and ⋅—at least one second light emitting element ( 120 ) adapted to emit light having an emission peak in a second wavelength range from 400 to 440 nm. The module according to the invention provides white light of acceptable color rendering with a “crisp white” effect.

First claim

The invention claimed is:

1. A light emitting module adapted to produce a crisp white effect when illuminating an object containing a fluorescent whitening agent, comprising:
a light source configured to emit first output light represented by a first color point in a chromaticity diagram, the first color point being on or below a black body line of the chromaticity diagram, and the first output light being white output light having an emission peak in a wavelength range from 400 to 440 nm, the light source comprising:
at least one first light emitting element adapted to emit normal blue light having an emission peak in a first wavelength range from 440 to 460 nm;
at least one wavelength converting material arranged to receive light emitted by said first light emitting element, and being capable of emitting light having an emission peak in the green to red wavelength range; and
at least one second light emitting element adapted to emit deep blue light having an emission peak in a second wavelength range from 400 nm to 440 nm, and providing a spectral contribution to the first output light emitted from the light source in a form of the emission peak in the second wavelength range from 400 to 440 nm without being converted by any wavelength converting material,

wherein the light emitting module mixes the light from the first light emitting element, the light from the wavelength converting material, and the light from the second light emitting element to emit the first output light of a sufficient intensity that satisfies a condition of 0.6≤A′≤3 to provide a desirable crisp white light effect when illuminating the object containing the fluorescent whitening agent which is excitable by the first output light, wherein A′ is defined as ratio of:

∫
380
430

⁢

E
⁡

(
λ
)

⁢
d
⁢

⁢

λ
⁡

(

430
-
λ

)

∫
380
780

⁢

E
⁡

(
λ
)

⁢
d
⁢

⁢
λ

=

A
′

,

wherein E(λ) is a spectral power distribution of the light emitted by the light emitting module and λ denotes a wavelength,
such that when being illuminated by the first output light, the object emits crisp white output light represented by a second color point of the chromaticity diagram, wherein the crisp white output light has the emission peak in the wavelength range from 400 to 440 nm, and the second color point is shifted further below the black body line than the first color point.

2. A light emitting module according to claim 1 , wherein the second wavelength range is from 405 to 425 nm.

3. A light emitting module according to claim 1 , comprising at least two different wavelength converting materials.

4. A light emitting module according to claim 1 , wherein the wavelength converting material has an absorption peak wavelength of higher than 440 nm.

5. A light emitting module according to claim 1 , wherein the wavelength converting material is a cerium-doped garnet.

6. A light emitting module according to claim 1 , comprising a plurality of said first light emitting element wherein the number ratio of said first light emitting elements to said second light emitting element is from 10:1 to 2:1.

7. A light emitting module according to claim 1 , wherein said wavelength converting material is a remote phosphor element.

8. A light emitting module according to claim 1 , wherein at least a portion of said wavelength converting material is provided on said first light emitting element and forms a phosphor converted white light emitting diode.

9. A method of producing white light using a light emitting module according to claim 1 , comprising
operating the light emitting module to emit the first output light to the object containing the fluorescent whitening agent, and
causing the first output light to be reflected from the object containing the fluorescent whitening agent to produce the crisp white light.

10. Use of a light emitting module according to claim 1 for illuminating an object comprising a fluorescent whitening agent.

11. A lamp, a spotlight or a luminaire comprising at least one light emitting module according to claim 1 .

12. A light emitting module adapted to produce a crisp white effect when illuminating an object containing a fluorescent whitening agent, comprising:
a light source configured to emit first output light represented by a first color point in a chromaticity diagram, the first color point being on or below a black body line of the chromaticity diagram, and the first output light being white output light having an emission peak in a wavelength range from 400 to 440 nm, the light source comprising:
at least one first light emitting element adapted to emit normal blue light having an emission peak in a first wavelength range from 440 to 460 nm;
at least one wavelength converting material arranged to receive light emitted by the first light emitting element, and being capable of emitting light having an emission peak in the green to red wavelength range; and
at least one second light emitting element adapted to emit deep blue light having an emission peak in a second wavelength range from 400 nm to 440 nm, and providing a spectral contribution to the first output light emitted from the light source in a form of the emission peak in the second wavelength range from 400 to 440 nm without being converted by any wavelength converting material,

such that when the first output light illuminates the object containing the fluorescent whitening agent which is excitable by the first output light, the object emits crisp white output light represented by a second color point of the chromaticity diagram, wherein the crisp white output light has the emission peak in the wavelength range from 400 to 440 nm, and the second color point is shifted further below the black body line than the first color point.

13. A light emitting module of claim 12 , wherein

Assignees

• Philips Lighting Holding Bv

Inventors

• Peeters Martinus Petrus Joseph
• De Beer Esther
• Van Kaathoven Dirk Jan
• Oepts Wouter
• Gielen Herman Johannes Gertrudis

Classifications

• H10W90/00

  Package configurations · CPC title

• F21K9/64

  using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer · CPC title

• F21K9/60

  Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction · CPC title

• H01L2924/0002

  Electricity · mapped topic

• H01L2924/00

  Electricity · mapped topic