Ceiling illumination device with bidirectional LED light sheet

• US 8,979,309 B2
• Filed: 04/05/2013
• Issued: 03/17/2015
• Est. Priority Date: 11/01/2010
• Status: Active Grant

• Current Assignee: Quarkstar LLC
• Original Assignee: Quarkstar LLC
• Inventors: Dau, Wilson, Lerman, Louis, York, Allan Brent
• Primary Examiner(s): Negron, Ismael
• Application Number:
  US13/857,789
• Publication Number:
  US 20140003041A1
• Time in Patent Office: 711 Days
• Field of Search: 362/242, 362/236, 362/244, 362/249.02, 362/249.06, 362649-659, 362/240, 362/147, 362/97.3, 362/404
• US Class Current: 362/249.06
• CPC Class Codes: F21K 9/60 Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction
• CPC Class Codes: F21S 8/04 intended only for mounting on a ceiling or the like overhead structures F21S8/02 takes precedence; details of ceiling bases F21V21/03
• CPC Class Codes: F21S 8/046 having multiple lighting devices, e.g. connected to a common ceiling base
• CPC Class Codes: F21S 8/06 by suspension
• CPC Class Codes: F21S 8/068 from a stretched wire
• CPC Class Codes: F21V 21/14 Adjustable mountings
• CPC Class Codes: F21V 21/16 using wires or cords
• CPC Class Codes: F21V 23/06 the elements being coupling devices , e.g. connectors
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 5/10 comprising photoluminescent material
• CPC Class Codes: F21V 7/00 Reflectors for light sources characterised by cooling arrangements F21V29/505
• CPC Class Codes: F21V 7/0016 on lighting devices that also provide for direct lighting, e.g. by means of independent light sources, by splitting of the light beam, by switching between both lighting modes
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2107/90 on two opposite sides of supports or substrates
• CPC Class Codes: F21Y 2109/00 Light sources with light-generating elements disposed on transparent or translucent supports or substrates
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 25/0756 Stacked arrangements of devices
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 1/189 : characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: H05K 2201/10106 : Light emitting diode [LED]

Abstract

An array of non-packaged LED dies is sandwiched between at least two transparent substrates having conductors bonded to the electrodes without wires. The light sheets are formed to emit light from opposite surfaces of the light sheet to create a bidirectional light sheet. The light sheet may be suspended from a ceiling to be perpendicular to the ceiling, or the angles of the light sheet may be adjusted.

Claims

1. A bidirectional lighting device for general illumination comprising:

a bidirectional light sheet comprising;

a first substrate comprising a first light emitting surface;

a second substrate comprising a second light emitting surface opposing the first light emitting surface;

a first plurality of non-packaged light emitting diode (LED) dies;

a second plurality of non-packaged light emitting diode (LED) dies, the first and second plurality of LED dies being disposed between the first and the second substrate such that during operation of the lighting device a peak intensity of light emitted by the first plurality of LED dies is output from the first light emitting surface in a first direction, and a peak intensity of light emitted by the second plurality of LED dies is output from the second light emitting surface in a second direction;

a plurality of optical elements disposed between at least some LED dies of the first and second plurality of LED dies to redirect light, wherein the optical elements are lenses; and

conductors formed on at least one of the first and second substrates, the conductors being electrically connected to electrodes of the first and second plurality of LED dies to provide power to the first and second plurality of LED dies; and

a support for affixing the bidirectional light sheet to a ceiling.

2. The device of claim 1, wherein the bidirectional light sheet is one of a plurality of bidirectional light sheets in the bidirectional lighting device, wherein at least two of the bidirectional light sheets emit a peak intensity of light at different angles.

3. The device of claim 1, wherein the bidirectional light sheet is affixed to the ceiling such that the first and second light emitting surfaces are substantially perpendicular to the ceiling.

4. The device of claim 1, wherein the support comprises wires and the bidirectional light sheet is suspended from the ceiling by the wires such that the first and second light emitting surfaces are substantially perpendicular to the ceiling.

5. The device of claim 1, wherein an angle of the light sheet relative to the ceiling is adjustable.

6. The device of claim 1, wherein the conductors comprise:

a first set of conductors; and

a second set of conductors, wherein

the first set of conductors is formed on the first substrate and electrically connected to an electrode of the first plurality of LED dies and an electrode of the second plurality of LED dies without wires, and

the second set of conductors is formed on the second substrate and electrically connected to an electrode of the first plurality of LED dies and an electrode of the second plurality of LED dies without wires.

7. The device of claim 1, wherein at least some of the first plurality and the second plurality of LED dies are connected in series by the conductors.

8. The device of claim 1, further comprising a third substrate sandwiched between the first substrate and the second substrate, the third substrate comprising optical elements to reflect light towards at least one of the first and second light emitting surface.

9. The device of claim 1, further comprising a reflective layer between the first substrate and the second substrate, wherein at least some of the first plurality and the second plurality of LED dies are located between the reflective layer and the light emitting surface of the first substrate, and other ones of the first plurality and the second plurality of LED dies are located between the reflective layer and the second light emitting surface of the second substrate.

10. The device of claim 1, further comprising one or more intermediate layers between the first substrate and the second substrate.

11. The device of claim 1, wherein the plurality of optical elements are substantially co-planar with at least one of the first and second plurality of LED dies and arranged between adjacent LED dies of the first and second plurality of LED dies.

12. The device of claim 1, wherein the optical elements are disposed adjacent to at least one of the first light emitting surface and the second light emitting surface.

13. The device of claim 1, wherein the plurality of optical elements comprises a first set of optical elements and a second set of optical elements, the first set of optical elements being disposed on the first substrate and the second set of optical elements being disposed on the second substrate.

14. The device of claim 13, wherein the first set of optical elements is shaped differently from the second set of optical elements such that the first set of optical elements directs light at different angles relative to the ceiling than the second set of optical elements.

15. The device of claim 1, wherein the bidirectional light sheet is one of a plurality of bidirectional light sheets in the bidirectional lighting device, wherein a second bidirectional light sheet of the plurality of bidirectional light sheets outputs a peak intensity of light in a third and fourth direction different from the first and second direction.

16. The device of claim 15, wherein a third bidirectional light sheet of the plurality of bidirectional light sheets outputs a peak intensity of light in a fifth and sixth direction.

17. The device of claim 1, wherein the bidirectional light sheet is curved and the bidirectional lighting device is suspended from the ceiling.

18. The device of claim 17 wherein the bidirectional light sheet substantially forms a cylinder having sides substantially perpendicular to the ceiling.

19. A bidirectional lighting device for general illumination comprising:

a bidirectional light sheet comprising;

a first substrate comprising a first light emitting surface;

a second substrate comprising a second light emitting surface opposing the first light emitting surface;

a first plurality of non-packaged light emitting diode (LED) dies;

a second plurality of non-packaged light emitting diode (LED) dies, the first and second plurality of LED dies being disposed between the first and the second substrate such that during operation of the lighting device a peak intensity of light emitted by the first plurality of LED dies is output from the first light emitting surface in a first direction, and a peak intensity of light emitted by the second plurality of LED dies is output from the second light emitting surface in a second direction;

a plurality of optical elements disposed between at least some LED dies of the first and second plurality of LED dies to redirect light, wherein the optical elements are prisms; and

conductors formed on at least one of the first and second substrates, the conductors being electrically connected to electrodes of the first and second plurality of LED dies to provide power to the first and second plurality of LED dies; and

a support for affixing the bidirectional light sheet to a ceiling.