Flexible LED lighting strip

• US 20050162850A1
• Filed: 09/27/2004
• Published: 07/28/2005
• Est. Priority Date: 08/26/2002
• Status: Active Grant

• Current Assignee: John F. Luk, Robert M. Altman
• Original Assignee: John F. Luk, Robert M. Altman
• Inventors: Luk, John F., Altman, Robert M.
• Granted Patent: US 7,210,818 B2
• Time in Patent Office: Days
• US Class Current: 362/227
• CPC Class Codes: F21S 4/26 of rope form, e.g. LED lighting ropes, or of tubular form
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2107/00 Light sources with three-dimensionally disposed light-generating elements
• 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 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• 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 2201/051 Rolled
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A flexible lighting device includes an elongated flexible tube with a translucent tube shell and opposed tube ends and a flexible circuit board set in the tube so that it extends between the tube ends. The flexible circuit board has opposed interior and exterior surfaces. Electrical circuitry is mounted to the circuit board and connected to an external input source and an output source of electrical power. The circuit board defines a number of cut-outs, preferably those of a generally diamond shape. The device is described in two embodiments: one with inwardly directed LEDs on the circuit board directed into the tube and one with outwardly directed LEDs on the circuit board directed out of the tube. The method of making the flexible lighting device is also described.

Claims

1. A flexible lighting device, comprising

an elongated translucent flexible cylindrical tube with opposed tube ends,

a flexible circuit board positioned in said tube extending between said opposed tube ends, said flexible circuit board having an exterior surface and an interior surface, said interior surface defining an elongated continuous cylindrical chamber between said opposed tube ends,

said flexible circuit board defining a plurality of cutouts between said interior and exterior surfaces between said tube ends, said cutouts being of such shape that allow the bending of said flexible circuit board,

a source of input electrical power,

a source of output electrical power,

electrical circuitry mounted to said flexible circuit board and connected to said input source of electrical power and to said output source of electrical power,

a plurality of LEDs mounted to said flexible circuit board and electrically connected to said electrical circuitry, wherein light emitted from said LEDs can pass at least in part through said cutouts and out said tube.

2. The flexible lighting device as recited in claim 1, wherein said tube has a tube axis and said flexible circuit board has a circuit board axis, said tube axis and said flexible circuit board axis defining a coextensive axis.

3. The flexible lighting device as recited in claim 2, wherein said plurality of LEDs has centerlines that are perpendicular to said coextensive axis.

4. The flexible lighting device as recited in claim 3, wherein said tube has a cylindrical inner side, said cylindrical exterior surface of said flexible circuit board and said cylindrical inner side of said tube define an elongated ring-shaped space, said plurality of LEDs including a plurality of inwardly directed LEDs positioned within said cylindrical chamber wherein light beams from said inwardly directed LEDs extend through said cutouts and out said tube.

5. The flexible lighting device as recited in claim 3, wherein said tube has a cylindrical inner side, said cylindrical exterior surface of said flexible circuit board and said cylindrical inner side of said tube define an elongated ring-shaped space, said plurality of LEDs including a plurality of outwardly directed LEDs positioned within said ring-shaped space wherein light beams from said outwardly directed LEDs extend directly out said tube.

6. The flexible lighting device as recited in claim 5, wherein said LEDs have LED lens portions that are juxtaposed with said cylindrical inner side of said tube.

7. The flexible lighting device as recited in claim 1, wherein said flexible circuit board has a length and wherein said cutouts are generally equal in size and are located at alternate opposed equal intervals along said length.

8. The flexible lighting device as recited in claim 1, wherein said flexible circuit board further includes means for providing strength to said flexible lighting device, said means for providing strength being secured to said flexible circuit board.

9. The flexible lighting device as recited in claim 8, wherein said means for providing strength is combined with a means for providing rigidity to maintain the shape of said flexible lighting device when said flexible lighting device is set in a plurality of various positions.

10. The flexible lighting device as recited in claim 9, wherein said means for providing strength and for providing rigidity includes at least one shape-retaining element secured to said flexible circuit board between said circuit board ends.

11. The flexible lighting device as recited in claim 10, wherein said at least one shape-retaining element is at least one flexible wire.

12. The flexible lighting device as recited in claim 11, wherein said at least one flexible wire is two flexible wires.

13. The flexible lighting device as recited in claim 9, wherein said means for providing strength and for providing rigidity includes at least one shape-retaining element secured to said flexible tube between said tube ends.

14. The flexible lighting device as recited in claim 10, wherein said means for providing strength and means for providing rigidity is at least one flexible electrically conductive metal wire, wherein said electrically conductive metal wire acts as a heat sink to draw the heat generated by said plurality of LEDs away from said LEDs.

15. The flexible lighting device as recited in claim 14, wherein said electrically conductive metal wire is substantially aluminum.

16. The flexible lighting device as recited in claim 14, wherein said electrically conductive metal wire is substantially copper.

17. The flexible lighting device as recited in claim 1, wherein said flexible circuit board is made of an electrically non-conductive material.

18. The flexible lighting device as recited in claim 17, wherein said electrically non-conductive material is an electrically non-conductive plastic;

19. The flexible lighting device as recited in claim 18, wherein said electrically non-conductive plastic is a polyimide.

20. The flexible lighting device as recited in claim 1, further including opposed end caps connected to said opposed tube ends.

21. The flexible lighting device as recited in claim 1, wherein said plurality of LEDs are white LEDs.

22. The flexible lighting device as recited in claim 21, wherein said electrical circuitry includes a chasing circuit for said white LEDs.

23. The flexible lighting device as recited in claim 1, wherein said plurality of LEDs are color LEDs.

24. The flexible lighting circuit as recited in claim 23, wherein said electrical circuitry includes color mixing, color changing, and color chasing control for said color LEDs.

25. The flexible lighting device as recited in claim 1, wherein said plurality of LEDs are color SMD LEDs.

26. The flexible lighting device as recited in claim 25, wherein said electrical circuitry includes color mixing, color changing, and color chasing control for said color SMD LEDs.

27. The flexible lighting device as recited in claim 23, wherein said color LEDs are Red, Green, Blue, and Yellow LEDs.

28. The flexible lighting device as recited in claim 25, wherein said color SMD LEDs are Red, Green, Blue, and Yellow LEDs.

29. A method for making a flexible LED lighting strip that includes the following steps:

a. Providing a biasable flat circuit board having an upper surface and a lower surface and opposed linear short edges and opposed linear long edges, the flat circuit board defining a plurality of diamond shaped cutouts located at regular intervals between the short edges and further defining a plurality of semi-diamond shaped cutouts opening at the long edges that are directly opposed one to the other generally midway between the diamond shaped cutouts opening at the long edges;

b. Mounting electrical circuitry including traces, solder pads, plated through holes and vias, and related electronic components in preparation for a plurality of LEDs to be mounted to the flat circuit board;

c. Securing the plurality of LEDs to the flat circuit board between the long edges and extending generally between the short edges, the LEDs having LED centerlines perpendicular to the flat circuit board;

d. Connecting the LEDs to the electrical circuitry;

e. Providing a translucent flexible hollow tube having a tube length and a tube inner diameter;

f. Forming the biasable flat circuit board into a biased mode tightly rolled circuit board having a cylindrical circuit board length that is generally equal to the tube length with the upper surface of the flat circuit board being the interior surface of the cylindrical circuit board and the lower surface of the flat circuit board being the exterior surface of the cylindrical circuit board, the LEDs being inwardly directed to the axis of the hollow tube; and

g. Pulling the tightly rolled circuit board into the tube and aligning the length of the rolled circuit board with the length of the tube and releasing the rolled circuit board from its biased mode wherein the rolled circuit board now becomes a partly rolled and cylindrical circuit board, and wherein the base portions of the inwardly directed LEDs are adjacent to the inner surface of assembled circuit board and the centerlines of the inwardly directed LEDs are perpendicular to the axis of the tube.

30. The method as recited in claim 29, further including the following steps:

a. Securing power input and power output terminals to the electrical circuitry of the assembled circuit board and the LEDs; and

b. Securing opposed end caps to the opposed ends of the tube.

31. The method as recited in claim 30, further including the steps of:

a. Mounting a male pin connector to one of the end caps;

b. Mounting a female socket connector to the other of the end caps; and

c. Mounting an optional removable cap cover to the male pin connector and another optional removable cap cover to the female socket connector.

32. A method for making a flexible LED lighting strip that includes the following steps:

a. Providing a biasable flat circuit board having an upper surface and a lower surface and opposed linear short edges and opposed linear long edges, the flat circuit board defining a plurality of diamond shaped cutouts located at regular intervals between the short edges and further defining a plurality of semi-diamond shaped cutouts opening at the long edges that are directly opposed one to the other generally midway between the diamond shaped cutouts opening at the long edges;

b. Mounting electrical circuitry including traces, solder pads, plated through holes and vias, and related electronic components in preparation for a plurality of LEDs to be mounted to the flat circuit board;

c. Securing the plurality of LEDs to the flat circuit board between the long edges and extending generally between the short edges, the LEDs having LED centerlines perpendicular to the flat circuit board;

d. Connecting the LEDs to the electrical circuitry;

e. Providing a translucent flexible hollow tube having a tube length and a tube inner diameter;

f. Forming the biasable flat circuit board into a biased mode tightly rolled circuit board having a cylindrical circuit board length that is generally equal to the tube length with the upper surface of the flat circuit board being the exterior surface of the cylindrical circuit board and the lower surface of the flat circuit board being the interior surface of the cylindrical circuit board, the LEDs being outwardly directed from the axis of the hollow tube; and

g. Pulling the tightly rolled circuit board into the tube and aligning the length of the rolled circuit board with the length of the tube and releasing the rolled circuit board from its biased mode wherein the rolled circuit board now becomes a partly rolled and cylindrical circuit board, wherein the lens portions of the outwardly directed LEDs are adjacent to the inner side of the tube and the center lines of the outwardly directed LEDs are perpendicular to the axis of the tube.

33. The method as recited in claim 32, further including the following steps:

a. securing power input and power output terminals to the electrical circuitry of the assembled circuit board and the LEDs; and

b. securing opposed end caps to the opposed ends of the tube.

34. The method as recited in claim 33, further including the steps of:

a. mounting a male pin connector to one of the end caps;

b. mounting a female socket to the other of the end caps; and

c. mounting an optional removal cap cover to the male pin connector and another optional removable cap cover to the female socked connector.

35. A flexible lighting device, comprising

an elongated flexible tube including a translucent tubular shell with opposed tube ends,

a flexible helical circuit board positioned in said tube extending between said opposed tube ends, said flexible helical circuit board having an exterior surface spaced from said tubular shell,

a source of input electrical power,

a source of output electrical power,

electrical circuitry mounted to said flexible helical circuit board and connected to said input source of electrical power and to said output source of electrical power, and

a plurality of light emitting diodes (LEDs) mounted to said exterior surface of said flexible helical circuit board and electrically connected to said electrical circuitry.