Lighting device and method for manufacturing a lighting device

Patent metadata

Field	Value
Publication number	US-9234635-B2
Application number	US-201113996778-A
Country	US
Kind code	B2
Filing date	Dec 9, 2011
Priority date	Dec 22, 2010
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

The invention relates to a lighting device and a method of manufacturing such a lighting device. The lighting device ( 1 ) comprises a first light emitting element ( 101 ) being optically coupled to a light guide ( 110 ) having an out-coupling surface ( 111 ) for illumination via the light guide. Further, the lighting device comprises a second light emitting element ( 102 ) dedicated for direct illumination from the lighting device. The invention is advantageous in that the lighting device provides both a decorative look and a functional illumination, and is still energy-efficient since the light emitted from the second light emitting element is directly emitted from the light emitting element without unnecessary energy-loss.

First claim

The invention claimed is:

1. A lighting device for providing decorative lighting, the device comprising:
a first light emitting element being optically coupled to a light guide having an out-coupling surface for decorative illumination via the light guide; and
a second light emitting element dedicated for direct functional illumination from the lighting device, said first light emitting element, said light guide, and said second light emitting element being disjointedly enclosed by an envelope;
the lighting device further having circuitry configured to control the light intensity of the first light emitting element and the second light emitting element;
wherein in decorative mode the circuitry is responsive to a first input signal so that the light intensity of the first light emitting element is lower than the light intensity of the second light emitting element;
wherein in functional mode the circuitry is responsive to a second input signal so that the light intensity of the second light emitting element is higher than light intensity of the first light emitting element for resemblance to the function of a traditional incandescent lighting device;
wherein the circuitry controls the color output of both the first light emitting element and the second light emitting element independently of each other.

2. A lighting device as defined in claim 1 , wherein the light intensity of the second light emitting element is adjustable relative to the light intensity of the first light emitting element, in response to an input signal to the lighting device.

3. A lighting device as defined in claim 2 , wherein at least one of the second light emitting element and the first light emitting element is dimmable.

4. A lighting device as defined in claim 3 , wherein a wavelength (color) of the light emitted from the first light emitting element is adjustable in response to an input signal to the lighting device.

5. A lighting device as defined in claim 4 , wherein the light guide comprises an optical fiber, a light guide plate or a three-dimensionally shaped light guide.

6. A lighting device as defined in claim 5 , wherein the light guide is provided with diffusing means for out-coupling light.

7. A lighting device as defined in claim 6 , wherein the structure of the out-coupling surface is selected to adjust scattering of the light.

8. A lighting device as defined in claim 7 , wherein the light guide comprises particles and/or vacuum/gas bubbles for out-coupling light.

9. A lighting device as defined in claim 8 , wherein at least one of the first light emitting element and the second light emitting element comprises at least one light emitting diode.

10. A lighting device as defined in claim 9 , wherein a string of a plurality of light emitting diodes is provided in the light guide.

11. A lighting device as defined in claim 10 , the envelope being at least semi-transparent.

12. A lighting device as defined in claim 11 , further comprising a base at which the first light emitting element and the second light emitting element are arranged.

13. A lighting device as defined claim 12 , wherein said base comprises a bayonet or screw base for retro-fitting a traditional incandescent light bulb.

14. A lighting device for providing decorative lighting and decorative color, comprising:
a first light emitting element being optically coupled to a light guide having an out-coupling surface for decorative illumination via the light guide; and
a second light emitting element dedicated for direct functional illumination from the lighting device, said first light emitting element, said light guide, and said second light emitting being enclosed by an envelope;
the lighting device further having circuitry configured to control the wavelength of light of the first light emitting element and the second light emitting element;
wherein the circuitry is responsive to a first input signal indicating a decorative mode so that the first light emitting element has a first wavelength and the second light emitting element is turned substantially off;
and wherein the circuitry is responsive to a second input signal indicating a functional mode so that the first light emitting element has a second wavelength different than the first wavelength and the second light emitting element has a third wavelength;
wherein the second and third wavelength are substantially one of yellow or white.

15. The lighting device of claim 14 wherein the first wavelength is substantially one of red/amber.

16. The lighting device of claim 1 wherein the circuitry controls the color output of both the first light emitting element and the second light emitting element and wherein the first low input signal places the lighting device in a decorative mode, the first light emitting element emitting a wavelength substantially of amber or red.

17. The lighting device of claim 16 wherein the circuitry controls the lighting device in response to a second input signal placing the lighting device in a functional mode, wherein in the functional mode the first light emitting element and the second light emitting element emits light substantially in a wavelength of either yellow or white.

18. The lighting device of claim 1 wherein the first low input signal places the lighting device in a decorative mode, the first light emitting element emitting a wavelength substantially of amber or red.

19. A method of controlling a lighting device for providing decorative lighting, the method comprising the steps of:
providing a first light emitting element;
providing a light guide having an out-coupling surface for decorative illumination via the light guide;
optically coupling the first light emitting element to the light guide;
providing a second light emitting element dedicated for direct functional illumination from the lighting device;
enclosing said first light emitting element, said light guide and said second light emitting element;
controlling the intensity with circuitry of the first light emitting element and the second light emitting element;
responsively correlating to a predefined relationship by the circuitry the light output intensity of the first light emitting element and the light output intensity of the second light emitting element
controlling the intensity with the circuitry so that the light intensity of the first light emitting element is lower than the light intensity of the second light emitting element for providing decorative illumination;
controlling the intensity with the circuitry so that the light intensity of the second light emitting element is higher than light intensity of the first light emitting element for providing functional illumination; and
controlling with the circuitry the color output of both the first light emitting element and the second light emitting element independently of each other.

Assignees

• Kwisthout Cornelis Wilhelmus
• Koninkl Philips Nv

Inventors

• Kwisthout Cornelis Wilhelmus

Classifications

• F21Y2103/10

  comprising a linear array of point-like light-generating elements · CPC title

• F21Y2107/70

  on flexible or deformable supports or substrates, e.g. for changing the light source into a desired form · CPC title

• F21Y2107/00

  Light sources with three-dimensionally disposed light-generating elements · CPC title

• F21K99/00 Primary

  Subject matter not provided for in other groups of this subclass · CPC title

• F21W2121/00

  Use or application of lighting devices or systems for decorative purposes, not provided for in codes F21W2102/00 – F21W2107/00 · CPC title