Solid state lamp using light emitting strips

• US 8,314,566 B2
• Filed: 02/22/2011
• Issued: 11/20/2012
• Est. Priority Date: 02/22/2011
• Status: Active Grant

• Current Assignee: Quarkstar LLC
• Original Assignee: Quarkstar LLC
• Inventors: Steele, Robert, Lerman, Louis, York, Allan Brent, Dau, Wilson, Teng, Jacqueline, Lerman, George
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): COOPER, JONATHAN G
• Application Number:
  US13/032,502
• Publication Number:
  US 20110163683A1
• Time in Patent Office: 637 Days
• Field of Search: 315/192, 362/231, 362/235, 362/240, 362/800, 362/249.02, 362/249.03, 362/249.04
• US Class Current: 315/185.R
• CPC Class Codes: F21K 9/23 Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/233 specially adapted for generating a spot light distribution, e.g. for substitution of reflector lamps
• CPC Class Codes: F21K 9/235 Details of bases or caps, i.e. the parts that connect the light source to a fitting; Arrangement of components within bases or caps F21K9/238 takes precedence
• CPC Class Codes: F21K 9/237 Details of housings or cases, i.e. the parts between the light-generating element and the bases; Arrangement of components within housings or cases F21K9/238 takes precedence
• CPC Class Codes: F21K 9/238 Arrangement or mounting of circuit elements integrated in the light source
• 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: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21K 9/65 specially adapted for changing the characteristics or the distribution of the light, e.g. by adjustment of parts
• CPC Class Codes: F21S 4/20 with light sources held by or within elongate supports
• CPC Class Codes: F21V 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 17/12 by screwing
• CPC Class Codes: F21V 17/14 Bayonet-type fastening
• CPC Class Codes: F21V 19/0025 the fastening means engaging the conductors of the light source, i.e. providing simultaneous fastening of the light sources and their electric connections
• CPC Class Codes: F21V 21/00 Supporting, suspending, or attaching arrangements for lighting devices F21V17/00, F21V19/00 take precedence; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q, stands for supporting apparatus or articles in general F16M11/00; Hand grips
• CPC Class Codes: F21V 23/02 the elements being transformers, impedances or power supply units, e.g. a transformer with a rectifier
• CPC Class Codes: F21V 23/06 the elements being coupling devices , e.g. connectors
• CPC Class Codes: F21V 29/10 Arrangement of heat-generating components to reduce thermal damage, e.g. by distancing heat-generating components from other components to be protected
• CPC Class Codes: F21V 29/505 of reflectors
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21V 3/00 : Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21V 3/02 : characterised by the 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 7/06 : with parabolic curvature
• CPC Class Codes: F21V 9/00 : Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters coloured shades F21V1/00; elements characterised by cooling arrangements F21V29/502
• CPC Class Codes: F21V 9/30 : 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 Class Codes: F21V 9/32 : characterised by the arrangement of the photoluminescent material
• CPC Class Codes: F21V 9/38 : Combination of two or more photoluminescent elements of different materials
• CPC Class Codes: F21Y 2101/00 : Point-like light sources
• CPC Class Codes: F21Y 2103/10 : comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2105/00 : Planar light sources
• CPC Class Codes: F21Y 2107/00 : Light sources with three-dimensionally disposed light-generating elements
• CPC Class Codes: F21Y 2107/20 : on convex supports or substrates, e.g. on the outer surface of spheres
• CPC Class Codes: F21Y 2107/30 : on the outer surface of cylindrical surfaces, e.g. rod-shaped supports having a circular or a polygonal cross section
• CPC Class Codes: F21Y 2107/90 : on two opposite sides of supports or substrates
• CPC Class Codes: F21Y 2115/10 : Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/15 : Organic light-emitting diodes [OLED]
• CPC Class Codes: H01L 25/0753 : the devices being arranged next to each other
• 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: H01L 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

In one embodiment, an LED lamp has a generally bulb shape. The LEDs are low power types and are encapsulated in thin, narrow, flexible strips. The LEDs are connected in series in the strips to drop a desired voltage. The strips are affixed to the outer surface of a bulb form to provide structure to the lamp. The strips are connected in parallel to a power supply, which may be housed in the lamp. Since many low power LEDs are used and are spread out over a large surface area, there is no need for a large metal heat sink. Further, the light emission is similar to that of an incandescent bulb. In other embodiment, there is no bulb form and the strips are bendable to have a variety of shapes. In another embodiment, a light sheet is bent to provide 360 degrees of light emission. Many other embodiments are described.

Claims

1. A solid state lamp comprising:

a plurality of flexible strips encapsulating bare, unpackaged light emitting diode (LED) dies, the bare, unpackaged LED dies being connected in series in the flexible strips, wherein the flexible strips are connected at one or more first terminals to a first voltage and connected at one or more second terminals to a second voltage;

a support structure for supporting the flexible strips;

an electrical connector affixed to the support structure for connection to an external power source for providing drive current to the strips; and

wherein the flexible strips or the support structure comprise one or more folds configured to allow the flexible strips or the support structure to extend or contract along a longitudinal direction and correspondingly decrease or increase a dimension of the solid state lamp in a transverse direction orthogonal to the longitudinal direction, where an illumination profile produced by the solid state lamp varies depending on the dimension of the solid state lamp.

2. The solid state lamp of claim 1, wherein the one or more folds are configured to allow the solid state lamp to be adjusted between a first configuration having a first longitudinal dimension and a second configuration having a second longitudinal dimension larger than the first longitudinal dimension, where the solid state lamp directs more illumination in the transverse direction in the second configuration than the first configuration.

3. The solid state lamp of claim 2, wherein the support structure has a corrugated shape, such that the support structure is compressible to allow compression of the solid state lamp, where the one or more folds comprise a plurality of folds of the support structure that are transverse to the longitudinal direction of the solid state lamp.

4. The solid state lamp of claim 3, wherein the plurality of flexible strips are placed between and parallel to adjacent ones of the plurality of folds of the support structure, such that bare, unpackaged LEDs of the plurality of flexible strips emit a portion of the light in the longitudinal direction and a remaining portion of the light in the transverse direction.

5. The solid state lamp of claim 3 wherein

each strip of the plurality of flexible strips comprises:

a first substrate having first conductors;

a second transparent substrate having second conductors;

a third transparent substrate having third conductors; and

a fourth transparent substrate,

a first portion of the bare, unpackaged LED dies are sandwiched between the first and second substrates, such that the first conductors connect the first portion of the bare, unpackaged LED dies on each strip in series, and the light emitted by the first portion of the bare, unpackaged LED dies is transmitted through the second, third and fourth transparent substrates,

a second portion of the bare, unpackaged LED dies are sandwiched between the second and the third substrates, such that the second conductors connect the second portion of bare, unpackaged LED dies on each strip in series, and the light emitted by the second portion of the bare, unpackaged LED dies is transmitted through the third and fourth transparent substrates,

a third portion of the bare, unpackaged LED dies are sandwiched between the third and the fourth substrates, such that the third conductors connect the third portion of bare, unpackaged LED dies on each strip in series, and the light emitted by the third portion of the bare, unpackaged LED dies is transmitted through the fourth transparent substrate, and

the first, second, and third conductors are connected to a three-way fixture switch to energize the first portion, the first and the second portions or the first, second and third portions of bare, unpackaged LED dies.

6. The solid state lamp of claim 5, further comprising a wavelength conversion material over the bare, unpackaged LED dies for generating white light.

7. The solid state lamp of claim 3, further comprising a power converter inside the solid state lamp, the converter generating the first voltage and the second voltage applied to the strips.

8. The solid state lamp of claim 7, wherein the second voltage is generated by a current source connected to all the strips such that the strips are connected in parallel.

9. The solid state lamp of claim 7, wherein the second voltage is generated by a plurality of current sources, each current source being connected to an associated strip to control a current through the associated strip by varying the second voltage for the associated strip.

10. The solid state lamp of claim 3, wherein the electrical connector comprises a connector for an Edison type socket.

11. The solid state lamp of claim 2, wherein

the flexible strips extend in the longitudinal direction of the solid state lamp from the support structure to an end of the solid state lamp opposite the support structure, each flexible strip comprising a uniform density of LED dies over a surface and at least one of the folds,

the folds of the flexible strips being oriented orthogonal to the longitudinal direction allowing compression of the solid state lamp in the longitudinal direction.

12. The solid state lamp of claim 11, wherein each strip of the plurality of flexible strips is diamond-shaped, and a fold associated with the strip comprises a crease of the strip.

13. The solid state lamp of claim 11, wherein each strip of the plurality of flexible strips comprises first and second halves of the strip, each of the first and second halves of the strip being trapezoidal-shaped, such that the first and second halves of the strip are joined at their larger of two bases to form a fold associated with the strip.

14. The solid state lamp of claim 11, wherein the electrical connector is foldable at a joint between the support structure and the electrical connector to enable compressed storage of the solid state lamp.

15. The solid state lamp of claim 11, comprising a power converter inside the solid state lamp, the power converter generating the first voltage and the second voltage applied to the strips.

16. The solid state lamp of claim 15, wherein the second voltage is generated by a current source connected to all the strips such that the strips are connected in parallel.

17. The solid state lamp of claim 15, wherein the second voltage is generated by a plurality of current sources, each current source being connected to an associated strip to control a current through the associated strip by varying the second voltage for the associated strip.

18. The solid state lamp of claim 11, wherein the electrical connector comprises a connector for an Edison type socket.

19. The solid state lamp of claim 11, wherein

each strip comprises:

a first substrate having first conductors;

a second transparent substrate having second conductors;

a third transparent substrate having third conductors; and

a fourth transparent substrate,

a first portion of the bare, unpackaged LED dies are sandwiched between the first and second substrates, such that the first conductors connect the first portion of the bare, unpackaged LED dies on each strip in series, and the light emitted by the first portion of the bare, unpackaged LED dies is transmitted through the second, third and fourth transparent substrates,

a second portion of the bare, unpackaged LED dies are sandwiched between the second and the third substrates, such that the second conductors connect the second portion of bare, unpackaged LED dies on each strip in series, and the light emitted by the second portion of the bare, unpackaged LED dies is transmitted through the third and fourth transparent substrates,

a third portion of the bare, unpackaged LED dies are sandwiched between the third and the fourth substrates, such that the third conductors connect the third portion of bare, unpackaged LED dies on each strip in series, and the light emitted by the third portion of the bare, unpackaged LED dies is transmitted through the fourth transparent substrate, and

the first, second, and third conductors are connected to a three-way fixture switch to energize the first portion, the first and the second portions or the first, second and third portions of bare, unpackaged LED dies.

20. The solid state lamp of claim 19, further comprising a wavelength conversion material over the bare, unpackaged LED dies for generating white light.