Jacketed LED assemblies and light strings containing same

• US 7,066,628 B2
• Filed: 01/13/2004
• Issued: 06/27/2006
• Est. Priority Date: 03/29/2001
• Status: Expired due to Term

• Current Assignee: Fiber Optic Designs Incorporated
• Original Assignee: Fiber Optic Designs Incorporated
• Inventors: Allen, David
• Primary Examiner(s): HUSAR, STEPHEN F
• Application Number:
  US10/755,463
• Publication Number:
  US 20040165384A1
• Time in Patent Office: 896 Days
• Field of Search: 362/255, 362/256, 362/267, 362/311, 362/363, 362/800, 362/645, 257/98, 257/99
• US Class Current: 362/267
• CPC Class Codes: F21S 4/10 with light sources attached to loose electric cables, e.g. Christmas tree lights
• CPC Class Codes: F21V 15/01 Housings, e.g. material or assembling of housing parts F21V15/02 takes precedence housings forming signs or letters G09F13/04
• CPC Class Codes: F21V 19/0005 of sources having contact pins, wires or blades, e.g. pinch sealed lamp F21V19/001 takes precedence
• CPC Class Codes: F21V 23/001 the elements being electrical wires or cables
• CPC Class Codes: F21V 31/005 Sealing arrangements therefor
• CPC Class Codes: F21V 31/04 Provision of filling media
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21W 2121/00 Use or application of lighting devices or systems for decorative purposes, not provided for in codes F21W2102/00 – F21W2107/00
• CPC Class Codes: F21W 2121/04 for Christmas trees
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/30107 Inductance
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• 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
• CPC Class Codes: H05B 45/37 : Converter circuits
• CPC Class Codes: H05B 45/40 : Details of LED load circuits
• CPC Class Codes: H05B 45/42 : Antiparallel configurations
• CPC Class Codes: Y02B 20/30 : Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
• CPC Class Codes: Y10S 362/80 : Light emitting diode

Abstract

A jacketed light emitting diode assembly is provided, which includes a light emitting diode including a set of positive and negative contacts, and a lens body containing a semiconductor chip and end portions of the contacts. An electrical wire set of first and second electrical wires are connected to the positive contact and the negative contact, respectively. A light transmissive cover receives the lens body, and has an opening through which at least one of the contact set and the electrical wire set passes. An integrally molded plastic jacket at the opening of the light transmissive cover provides a seal at the opening against moisture and airborne contaminants. A waterproof light string including one or more of the jacketed light emitting diode assemblies is also provided, as are related methods.

Claims

1. A jacketed light emitting diode assembly, comprising:

a light emitting diode comprising

a contact set comprising a positive contact and a negative contact, each of the contacts having a first end portion and a second end portion; and

a lens body containing a semiconductor chip and the first end portions of the positive and negative contacts;

an electrical wire set comprising a first electrical wire and a second electrical wire electrically connected to the second end portions of the positive contact and the negative contact, respectively;

a light transmissive cover having a cavity with an opening, the cavity receiving the lens body, the opening having at least one of the contact set and the electrical wire set passing therethrough; and

an integrally molded plastic jacket at the opening of the light transmissive cover to provide a seal at the opening against moisture and airborne contaminants.

2. A jacketed light emitting diode assembly according to claim 1, wherein electrically connected portions of the contact set and the electrical wire set are encased by the integrally molded plastic jacket to provide a seal against moisture and airborne contaminants.

3. A jacketed light emitting diode assembly according to claim 1, wherein the electrical wire set passes through the opening, and wherein the integrally molded plastic jacket encases respective regions of the electrical wire set passing through the opening.

4. A jacketed light emitting diode assembly according to claim 1, wherein the contact set passes through the opening, and wherein the integrally molded plastic jacket encases electrical connections between the contact set and the electrical wire set.

5. A jacketed light emitting diode assembly according to claim 1, wherein the integrally molded plastic jacket comprises at least one of polycarbonate, polystyrene, and other moldable plastic material.

6. A jacketed light emitting diode assembly according to claim 1, wherein the integrally molded plastic jacket comprises a plastic selected from poly(vinyl chloride).

7. A jacketed light emitting diode assembly according to claim 1, wherein the integrally molded plastic jacket comprises polypropylene.

8. A jacketed light emitting diode assembly according to claim 1, wherein the light transmissive cover is at least partially encased by the integrally molded plastic jacket.

9. A method for making a jacketed light emitting diode assembly, comprising:

providing a light emitting diode comprising a positive contact and a negative contact of a contact set, each of the contacts having a first end portion and a second end portion, and a lens body containing a semiconductor chip and the first end portions of the positive and negative contacts;

electrically connecting a first electrical wire and a second electrical wire of an electrical wire set to the second end portions of the positive contact and the negative contact, respectively;

inserting the light emitting diode through an opening and into a cavity of a light transmissive cover, the opening having at least one of the contact set and the electrical wire set passing therethrough; and

molding a plastic jacket integrally at the opening of the light transmissive cover to provide a seal at the opening against moisture and airborne contaminants.

10. A method according to claim 9, wherein electrically connected portions of the contact set and the electrical wire set are encased by the integrally molded plastic jacket to provide a seal against moisture and airborne contaminants.

11. A method according to claim 9, wherein the electrical wire set passes through the opening, and wherein the plastic jacket encases respective regions of the electrical wire set passing through the opening.

12. A method according to claim 9, wherein the contact set passes through the opening, and wherein the plastic jacket encases electrical connections between the contact set and the electrical wire set.

13. A method according to claim 9, wherein the plastic jacket comprises at least one of polycarbonate, polystyrene, or other moldable plastic material.

14. A method according to claim 9, wherein the plastic jacket comprises a plastic selected from poly(vinyl chloride).

15. A method according to claim 9, wherein the plastic jacket comprises polypropylene.

16. A method according to claim 9, wherein the light transmissive cover is at least partially encased by the integrally molded plastic jacket.

17. A method according to claim 9, wherein said molding comprises injection molding the plastic jacket in a mold cavity.

18. A light string comprising a plurality of light emitting diode assemblies connected to one another, the light emitting diode assemblies comprising a plurality of jacketed light emitting diode assemblies, comprising:

a light emitting diode comprising

a contact set comprising a positive contact and a negative contact, each of the contacts having a first end portion and a second end portion; and

a lens body containing a semiconductor chip and the first end portions of the positive and negative contacts;

an electrical wire set comprising a first electrical wire and a second electrical wire electrically connected to the second end portions of the positive contact and the negative contact, respectively;

a light transmissive cover having a cavity with an opening, the cavity receiving the lens body, the opening having at least one of the contact set and the electrical wire set passing therethrough; and

an integrally molded plastic jacket at the opening of the light transmissive cover to provide a seal at the opening against moisture and airborne contaminants along a length of the light string.

19. A light string according to claim 18, wherein electrically connected portions of the contact set and the electrical wire set are encased by the integrally molded plastic jacket to provide a seal against moisture and airborne contaminants.

20. A light string according to claim 18, wherein the electrical wire set passes through the opening, and wherein the integrally molded plastic jacket encases respective regions of the electrical wire set passing through the opening.

21. A light string according to claim 18, wherein the contact set passes through the opening, and wherein the integrally molded plastic jacket encases electrical connections between the contact set and the electrical wire set.

22. A light string according to claim 18, wherein the integrally molded plastic jacket comprises at least one of polycarbonate, polystyrene, or other moldable plastic material.

23. A light string according to claim 18, wherein the integrally molded plastic jacket comprises a plastic selected from poly(vinyl chloride).

24. A light string according to claim 18, wherein the integrally molded plastic jacket comprises polypropylene.

25. A light string according to claim 18, wherein the light transmissive cover is at least partially encased by the integrally molded plastic jacket.

26. A light string according to claim 18, the light emitting diode assemblies being adapted to be directly connected to an AC power source and providing a stable light source, the light string formed by a method of determining a workable number of light emitting diodes directly coupled in series to the AC power source to provide the stable light source, said method comprising the following steps:

determining an RMS voltage rating (V_RMS) of said AC power source;

determining an AC voltage rating for a particular type of light emitting diodes by determining an average voltage drop (V_avg) across said particular type of light emitting diode when connected to said AC power source;

calculating said workable number (WN) of said light emitting diodes according to the following formula

WN=V_RMS/V_avg; and

electrically interconnecting a plurality of said particular type of light emitting diodes equal to said workable number (WN) in series directly to said AC power source without any intermediate circuit altering devices.

27. A method for moisture sealing a light-emitting diode elements of a light string, comprising:

providing a light string comprising a plurality of light emitting diodes, the plurality of light emitting diodes comprising a positive contact and a negative contact of a contact set, each of the contacts having a first end portion and a second end portion, and a lens body containing a semiconductor chip and the first end portions of the positive and negative contacts;

electrically connecting a first electrical wire and a second electrical wire of an electrical wire set to the second end portions of the positive contact and the negative contact, respectively;

inserting the light emitting diode through an opening and into a cavity of a light transmissive cover, the opening having at least one of the contact set and the electrical wire set passing therethrough; and

molding a plastic jacket integrally at the opening of the light transmissive cover to provide a seal at the opening against moisture and airborne contaminants.

28. A method according to claim 27, wherein electrically connected portions of the contact set and the electrical wire set are encased by the integrally molded plastic jacket to provide a seal against moisture and airborne contaminants.

29. A method according to claim 27, wherein the plastic jacket comprises at least one of polycarbonate, polystyrene, or other moldable plastic material.

30. A method according to claim 27, wherein the plastic jacket comprises a plastic selected from poly(vinyl chloride).

31. A method according to claim 27, wherein the plastic jacket comprises polypropylene.

32. A method according to claim 27, wherein the light transmissive cover is at least partially encased by the integrally molded plastic jacket.

33. A method according to claim 27, wherein said molding comprises injection molding the plastic jacket in a mold cavity.

34. A method according to claim 27, further comprising determining a workable number of the light emitting diode assemblies directly coupled in series to an AC power source to provide a stable light source, said determining of a workable number comprising the following steps:

determining an RMS voltage rating (V_RMS) of said AC power source;

determining an AC voltage rating for a particular type of light emitting diodes by determining an average voltage drop (V_avg) across said particular type of light emitting diode when connected to said AC power source;

calculating said workable number (WN) of said light emitting diodes according to the following formula

WN=V_RMS/V_avg; and

electrically interconnecting a plurality of said particular type of light emitting diodes equal to said workable number (WN) in series directly to said AC power source without any intermediate circuit altering devices.