Phosphor-enhanced lighting device, retrofit light bulb and light tube with reduced color appearance

Patent metadata

Field	Value
Publication number	US-9755117-B2
Application number	US-201214114930-A
Country	US
Kind code	B2
Filing date	Apr 17, 2012
Priority date	May 6, 2011
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A phosphor-enhanced lighting device 100 , a retrofit light bulb, a light tube and a luminaire are provided. The phosphor-enhanced lighting 100 device comprises a light source 116 , a light exit window 102 , a first light conversion element 112 and a second light conversion element 110 . The light source 116 emits through its light emitting surface 118 source light 114 of a pre-defined color spectrum. The light exit window 102 emits light into an ambient of the phosphor-enhanced lighting device 100 . The first light conversion element 112 comprises an inorganic luminescent material which absorbs a part of the source light 114 and converts a part of the absorbed light to light of a first color 104 . The second light conversion element 110 comprises a first organic luminescent material which absorbs a part of the source light 114 and/or absorbs apart of the light 104 of the first color. The first organic luminescent material converts a part of the absorbed light to light of the second color 108 . The second light conversion element 110 is optically arranged in between the light exit window 102 and the light emitting surface 118 of the light source 116 . The first light conversion element 112 is optically arranged in between the second light conversion element 110 and the light emitting surface 118 of the light source 116 . A gap 111 is present between the first light conversion element 112 and the second light conversion element 110.

First claim

The invention claimed is:

1. A phosphor-enhanced lighting device comprising:
a light source disposed on a base, the light source comprising a light emitting surface for emitting source light of a predefined color spectrum, a light exit window for emitting light into an ambient of the phosphor-enhanced lighting device,
a first light conversion element comprising an inorganic luminescent material, the inorganic luminescent material being configured to absorb a part of the source light and to convert a part of the absorbed light to light of a first color,
a second light conversion element extending in a first plane from a first end to a second end comprising a first organic luminescent material, the first organic luminescent material being configured to absorb a part of the source light or to absorb a part of the light of the first color, and the first organic luminescent material being configured to convert a part of absorbed lights to light of a second color,
wherein the second light conversion element is optically arranged in between the light exit window and a top light emitting surface of the light source, the first light conversion element is optically arranged in between the second light conversion element and the top light emitting surface of the light source and the first light conversion element is arranged directly on the top light emitting surface of the light source such that a bottom surface of the first light conversion element is in contact with the top light emitting surface of the light source, wherein the bottom surface of the first light conversion element extends only to a boundary of a perimeter of the top light emitting surface of the light source, and wherein a gap is between the first light conversion element and the second light conversion element.

2. The phosphor-enhanced lighting device according to claim 1 , wherein the first light conversion has a first surface facing the light exit window, the second light conversion element has a second surface facing the light exit window, and the first surface is smaller than the second surface.

3. The phosphor-enhanced lighting device according to claim 1 wherein the light source is a blue light emitting light emitting diode, the inorganic luminescent material is a yellow or yellow-green emitting inorganic phosphor, and a light emission through the light exit window that is, in operation, a combination of source light and the light of the first color has a correlated color temperature that is higher than 10,000K and has a color point in a color space at about a black body line in the color space.

4. The phosphor-enhanced lighting device according to claim 1 wherein a combination of the light source with the light emitting surface on which the first light conversion element is arranged has an optical package efficiency that is larger than 80%, the optical package efficiency being defined by a percentage of all photons emitted by the light source which are emitted by the combination of the light source and the first light conversion element.

5. The phosphor-enhanced lighting device according to claim 1 , wherein the second light conversion element has a second refractive index.

6. The phosphor-enhanced lighting device according to claim 1 , wherein the second light conversion element is arranged at the light exit window or wherein the second light conversion element forms the light exit window.

7. The phosphor-enhanced lighting device according to claim 1 , wherein the light source is a solid state light emitter.

8. The phosphor-enhanced lighting device according to claim 1 , wherein at least one of the first light conversion element and the second light conversion element is a layer.

9. The phosphor-enhanced lighting device according to claim 1 , wherein the second light conversion element comprises a second organic luminescent material, the second organic luminescent material being configured to absorb a part of the source light or to absorb a part of the light of the first color or to absorb a part of the light of the second color, and the second organic luminescent material being configured to convert a part of the absorbed light to light of a third color.

10. The phosphor-enhanced lighting device according to claim 9 , wherein the second light conversion element is a stack of layers comprising a first layer and a second layer, the first layer comprising the first organic luminescent, material and not comprising the second organic luminescent material, and the second layer comprising the second organic luminescent material and not comprising the first organic luminescent material.

11. The phosphor-enhanced lighting device according to claim 1 comprising a scattering layer or the second light conversion element comprises scattering particles, wherein the scattering layer is optically arranged in between the light exit window and the second light conversion element.

12. A retrofit light bulb comprising the phosphor-enhanced lighting device according to claim 1 .

13. A luminaire comprising the phosphor-enhanced lighting device according to claim 1 .

14. The phosphor-enhanced lighting device according to claim 1 , wherein the gap is filled with a fluid wherein the fluid is a liquid.

15. The phosphor-enhanced lighting device according to claim 1 , further comprising one or more walls interposed between the base and the second light conversion element.

Assignees

• Hikmet Rifat Ata Mustafa
• Van Bommel Ties
• Philips Lighting Holding Bv

Inventors

• Hikmet Rifat Ata Mustafa
• Van Bommel Ties

Classifications

• F21K9/64

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

• F21V9/30

  Elements containing photoluminescent material distinct from or spaced from the light source (shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40) · CPC title

• C09K11/06

  containing organic luminescent materials · CPC title

• C09K11/7774

  Aluminates · CPC title

• H01L33/507

  Electricity · mapped topic