Illuminated signage employing light emitting diodes

• US 20050030765A1
• Filed: 05/24/2002
• Published: 02/10/2005
• Est. Priority Date: 05/25/2001
• Status: Active Grant

• Current Assignee: Current Lighting Solutions, LLC (f/k/a GE Lighting Solutions, LLC) (American Industrial Partners)
• Original Assignee: Lumination LLC
• Inventors: Aanegola, srinath K., Petroski, James T., Southard, Paul, Bohler, Christopher
• Granted Patent: US 7,217,012 B2
• Time in Patent Office: Days
• US Class Current: 362/559
• CPC Class Codes: F21S 4/20 with light sources held by or within elongate supports
• CPC Class Codes: F21V 21/002 making direct electrical contact, e.g. by piercing F21V21/35 takes precedence
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G09F 13/0404 the light source being enclosed in a box forming the character of the sign
• CPC Class Codes: G09F 13/0413 Frames or casing structures therefor
• CPC Class Codes: G09F 13/22 electroluminescent electroluminescent light sources per se H05B33/00
• CPC Class Codes: G09F 9/33 being semiconductor devices, e.g. diodes
• CPC Class Codes: Y10S 362/80 Light emitting diode
• CPC Class Codes: Y10S 362/812 Signs

Abstract

An illuminated sign (88) includes a flexible electrical power cord (100) including first and second parallel conductors (112, 114) surroundingly contained within an insulating sheath defining a constant separation distance between the parallel conductors (112, 114). A plurality of light emitting diode (LED) devices (102) are affixed to the cord (100). Each LED device (102) includes an LED (104) having a positive lead (130p) electrically communicating with the first parallel conductor (112) and a negative lead (130p) electrically communicating with the second parallel conductor (114). A stencil (92) defines a selected shape, and the electrical cord (100) is arranged on the stencil (92). Power conditioning electronics (210, 220) disposed away from the stencil (92) electrically communicate with the first and second parallel conductors (112, 114) of the electrical power cord (100). The power conditioning electronics (210, 220) power the LED devices (102) via the parallel conductors (112, 114).

Claims

1. An illuminated sign comprising:

a flexible electrical power cord including first and second parallel conductors surroundingly contained within an insulating sheath defining a constant separation distance between the parallel conductors;

a plurality of light emitting diode (LED) devices affixed to the cord, each LED device including an LED having a positive lead electrically communicating with the first parallel conductor and a negative lead electrically communicating with the second parallel conductor;

a stencil defining a selected shape and onto which the electrical cord is arranged; and

power conditioning electronics disposed away from the stencil and electrically communicating with the first and second parallel conductors of the electrical power cord, the power conditioning electronics powering the LED devices via the parallel conductors.

2. The illuminated sign as set forth in claim 1, further including:

a housing inside which the stencil, LED devices, and electrical power cord are arranged, the power conditioning electronics disposed outside of and away from the housing, the housing further defining the selected shape and including a light transmissive region arranged to transmit light generated by the plurality of LED devices.

3. The illuminated sign as set forth in claim 1, wherein each LED device includes:

a connector including;

a first region onto which an LED is secured, and

a second region that mechanically connects with the electrical power cord, the second region including a positive prong that electrically contacts the positive LED lead and the first parallel conductor, and a negative prong that electrically contacts the negative LED lead and the second parallel conductor.

4. The illuminated sign as set forth in claim 3, wherein each connector further includes:

a flange adapted for affixing the connector to the stencil.

5. The illuminated sign as set forth in claim 3, wherein the second region includes a fastener that mechanically secures onto the electrical power cord, the mechanical securing simultaneously electrically contacting the positive and negative prongs with the first and second conductors, respectively.

6. The illuminated sign as set forth in claim 1, wherein the flexible electrical power cord further includes:

a plurality of cords each including first and second parallel conductors surroundingly contained within a continuous insulating sheath defining a constant separation distance between the parallel conductors; and

at least one splice connector that mechanically joins the plurality of cords, the splice connector electrically connecting the first conductors of the plurality of cords, and electrically connecting the second conductors of the plurality of cords.

7. An article of manufacture for installing a plurality of light emitting diodes (LEDs) into a channel letter housing having at least one light-transmissive surface, the article of manufacture comprising:

a substantially rigid structure which is pre-formed or formable for arrangement in the channel letter housing;

a flexible cable including at least two flexible parallel conductors arranged to support an electrical potential difference therebetween;

a plurality of LEDs electrically parallel-interconnected by communication of the anode and cathode of each LED with the at least two conductors of the flexible cable;

a fastener that secures at least a portion of the flexible cable onto the rigid structure; and

a power module that receives power having first characteristics and converts the received power to a supply power having second characteristics which is communicated to the at least two conductors of the flexible cable to power the plurality of parallel-interconnected LEDs.

8. The article of manufacture as set forth in claim 7, further including:

a plurality of connectors corresponding to the plurality of LEDs, each connector retaining an LED and mechanically connecting with the cable, and each connector including a first conductive element that contacts the LED anode and one of the at least two conductors, each connector further including a second conductive element that contacts the LED cathode and another of the at least two conductors.

9. The article of manufacture as set forth in claim 8, wherein the fastener for securing at least a portion of the flexible cable onto the rigid structure includes:

a bracket arranged on each of the plurality of connectors for securing the connector to the rigid structure.

10. The article of manufacture as set forth in claim 8, wherein the connector further includes:

first and second connector sections that snap together about a portion of the flexible cable to secure the connector to the cable portion.

11. The article of manufacture as set forth in claim 10, wherein the connecting region includes:

ends of the first and second conductive elements that extend outward from the first connector section toward the second connector section, the ends including insulation-piercing tips that displace an insulative coating of the flexible cable to contact the respective two cable conductors.

12. The article of manufacture as set forth in claim 11, wherein the insulation-piercing tips each include:

a bifurcated portion that receives the respective cable conductor.

13. A light emitting diode (LED) light engine, comprising:

an electrical cable including;

at least two flexible electrical conductors, and

a flexible, electrically insulating covering surrounding the electrical conductors, the conductors arranged substantially parallel with a selected separation therebetween; and

an LED with a plurality of electrical leads separated by the selected separation which electrically contact the electrical conductors and mechanically pierce the insulating covering to mechanically secure the LED to the electrical cable.

14. The LED light engine as set forth in claim 13, wherein each of the conductors includes a plurality of strands and is about 14 gauge.

15. The LED light engine as set forth in claim 13, wherein each of the electrical leads is wedge-shaped.

16. The LED light engine as set forth in claim 13, wherein the flexible covering includes a plurality of dips positioned for aligning the leads with the flexible elements.

17. A light emitting diode (LED) light engine including:

an electrical cable including a positive flexible conductor connected with an associated positive source of electrical power, a negative flexible conductor connected with an associated negative source of electrical power, and an electrically insulating covering surrounding and electrically insulating the positive and negative conductors and holding the conductors separate at a selected separation distance;

an LED including positive and negative leads; and

a connector mechanically secured to the flexible insulating covering, the connector including positive and negative prongs that pierce the insulating covering and electrically contact the positive and negative conductors, respectively, the connector further having the LED mounted thereon with the positive and negative leads of the LED electrically contacting the positive and negative prongs, respectively.

18. The LED light engine as set forth in claim 17, wherein:

each of the connector prongs is V-shaped; and

each of the electrical cable conductors is positioned within an opening defined by the respective V-shaped connector prong.

19. The LED light engine as set forth in claim 18, wherein the connector includes a locking tab for securing the connector in a locked position, the cable conductors being positioned within the respective V-shaped connector prongs when the connector is in the locked position.

20. A method of manufacturing an LED light engine, the method comprising:

insulating a plurality of conductive elements to form a flexible electrically insulating conductor;

mechanically securing an LED to the insulated conductive elements; and

simultaneously with the mechanical securing, electrically contacting a plurality of leads of the LED to respective ones of the conductive elements.

21. The method of manufacturing an LED light engine as set forth in claim 20, wherein the securing step includes:

displacing an insulating covering over one of the conductive elements; and

inserting one of the LED leads into the displaced covering.

22. The method of manufacturing an LED light engine as set forth in claim 21, wherein the conductive elements include a plurality of conductive strands, the contacting step including:

passing one of the LED leads through an insulating covering over one of the conductive elements; and

inserting the LED lead between the conductive strands of the conductive element.

23. The method of manufacturing an LED light engine as set forth in claim 22, wherein the insulating covering includes a groove, further including, before the passing step:

aligning the LED lead with the conductive element via the groove.

24. The method of manufacturing an LED light engine as set forth in claim 20, wherein:

the securing step includes;

mechanically attaching a connector to an insulating covering on the conductor; and

the contacting step includes;

passing an electrical contact, secured to the connector, through the insulating covering so that an electrical connection is made between the contact and a respective one of the conductive elements.

25. The method of manufacturing an LED light engine as set forth in claim 24, wherein the electrical contact is V-shaped, the passing step including:

securing the conductive element within the V-shaped contact.

26. A flexible lighting device comprising:

a flexible cable including an electrically insulating sheath which contains positive and negative conductors electrically isolated from one another, the sheath providing a spacing between the positive and negative conductors; and

a plurality of light emitting diode (LED) devices spaced apart from one another on the cable, each of the LED devices having an LED including positive and negative leads mounted on a connector which mechanically secures the LED device to a portion of the flexible cable and electrically connects the positive and negative LED leads to the positive and negative conductors through positive and negative conductive piercing members which pierce the sheath to make electrical contact with the respective conductors.

27. The flexible lighting device as set forth in claim 26, wherein each connector includes:

an LED mount region that receives the LED;

a clamp region that secures the connector to the portion of the flexible cable, the clamp region aligning the positive and negative conductive piercing members with the positive and negative conductors of the flexible cable, each conductive piercing member including an insulation-piercing end that displaces the insulating sheath when the clamp region is secured to electrically contact with the respective conductor; and

a fastening region for fastening the connector onto an associated supporting structure.

28. The flexible lighting device as set forth in claim 27, wherein the fastening region of each connector includes:

an opening adapted to cooperate with a fastener to fasten the connector to the associated supporting structure.

29. The flexible lighting device as set forth in claim 26, wherein each conductive piercing member includes:

a bifurcated end defining a gap sized to receive the respective conductor.

30. The flexible lighting device as set forth in claim 29, wherein each electrical cable conductor is a multi-stranded conductor, and the conductor is compressively held within the bifurcated end.

31. The flexible lighting device as set forth in claim 26, wherein each connector includes:

a first section including an LED mount region that receives the LED; and

a second section that cooperates with the first section to define a clamp region;

wherein the first and second sections snap together with the flexible cable portion arranged therebetween to secure the connector to the flexible cable, the snapping causing the conductive piercing members to pierce the sheath and make electrical contact with the respective conductors.

32. The flexible lighting device as set forth in claim 31, wherein the insulating sheath of the flexible cable includes:

dips arranged on the surface of the sheath and corresponding with the positive and negative electrical conductors, the dips receiving ends of the conductive piercing members to align the flexible cable portion between the first and second connector sections prior to the snapping theretogether.

33. The flexible lighting device as set forth in claim 26, wherein the positive and negative conductors within the insulating sheath define a cable plane, the flexible electrical cable being flexible in a direction out of the cable plane, the LED emitting light substantially directed parallel to the cable plane.

34. The flexible lighting device as set forth in claim 26, wherein intervening cable portions between the spaced apart LED devices are selectively flexed to define a selected channel lettering.

35. The flexible lighting device as set forth in claim 26, wherein the flexible cable includes first and second flexible cables, the flexible lighting device further including:

a splice connector that mechanically and electrically connects first and second flexible cables, the splice connector including positive and negative conductive piercing members which pierce the sheaths of the first and second cables to make electrical contact with the respective conductors.

36. A light emitting diode (LED) lighting apparatus comprising:

a flexible electrical cable including an anode wire and a cathode wire arranged in an electrically isolating sheath;

a plurality of LED devices spaced apart along the cable and mechanically and electrically connected therewith, each LED device including;

an LED having at least one anode lead and at least one cathode lead, and

a connector including an LED socket that receives the anode and cathode leads, the LED socket mechanically retaining the LED, the connector further including a first electrically conductive path between the anode lead and the anode wire, and a second electrically conductive path between the cathode lead and the cathode wire, the first and second conductive paths displacing portions of the cable sheath.

37. The LED lighting apparatus as set forth in claim 36, wherein the first and second conductive paths each include:

an electrically conductive element contacting the LED lead, the conductive element including an insulation-piercing end that displaces a portion of the cable sheath and contacts the respective cable wire.

38. The LED lighting apparatus as set forth in claim 37, wherein the connector includes first and second sections that surroundingly clamp onto a portion of the cable, the insulation piercing ends of the first and second conductive paths extending into the clamp portion such that they pierce the cable sheath responsive to the clamping to effectuate contact with the respective cable wires.

39. The LED lighting apparatus as set forth in claim 37, wherein each insulation piercing end includes a bifurcation that receives a portion of the anode or cathode wire without cutting said wire.

40. The LED lighting apparatus as set forth in claim 37, wherein the LED leads and the conductive elements include an electrically conductive surface material of the same type.

41. The LED lighting apparatus as set forth in claim 37, wherein the anode and cathode wires and the conductive elements include an electrically conductive surface material of the same type.

42. The LED lighting apparatus as set forth in claim 37, wherein the anode and cathode wires, the conductive elements, and the LED leads each include an electrically conductive surface selected to substantially reduce galvanic corrosion at electrically contacting surfaces therebetween.

43. The LED lighting apparatus as set forth in claim 37, wherein the contacting of the electrically conductive element with the LED lead effectuates electrical contact without cooperation of an electrically conductive solder.

44. The LED lighting apparatus as set forth in claim 36, wherein the first and second conductive paths include:

an electrically conductive anode prong;

an electrically conductive cathode prong;

an anode prong recess that receives the anode prong; and

a cathode prong recess that receives the cathode prong;

wherein the prong recesses communicate with the LED socket such that the LED leads penetrate the prong recesses to contact with the prongs.

45. The LED lighting apparatus as set forth in claim 36, wherein each connector includes one LED socket.

46. The LED lighting apparatus as set forth in claim 36, further including:

a stencil defining a selected letter or symbol, the flexible electrical cable arranged on the stencil to light the selected letter or symbol.

47. The LED lighting apparatus as set forth in claim 46, wherein the electrical cable is fastened onto the stencil via the connectors.

48. The LED lighting apparatus as set forth in claim 46, wherein the stencil includes a plurality of stencils defining a plurality of letters or symbols, and the flexible electrical cable includes a plurality of flexible electrical cables arranged on the plurality of stencils, the LED lighting apparatus further including:

a power supply having a plurality of individually adjustable power output lines each electrically powering one or more flexible electrical cables, the individually adjustable power output lines selectively adjusted such that the intensities produced by the flexible electrical cables are substantially uniform.