Light-emitting diode

• US 4,698,730 A
• Filed: 08/01/1986
• Issued: 10/06/1987
• Est. Priority Date: 08/01/1986
• Status: Expired due to Term

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: Sakai, Hirou, Kawamura, Toshihide
• Primary Examiner(s): Yeung, James C.
• Application Number:
  US06/892,503
• Time in Patent Office: 431 Days
• Field of Search: 362/311, 362/800, 362/320, 362/339, 362/62, 362/80, 313/110-114
• US Class Current: 362/311.05
• CPC Class Codes: F21V 17/04 the fastening being onto or by the light source
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/0091 using total internal reflection
• 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 2924/00012 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 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A light-emitting element of a light-emitting diode is mounted on a lead frame, stem or substrate, and is molded with resin so as to form a lens portion. A cap made of a light-transparent resin and having a hollow portion at the center thereof and an outer pheripheral surface, is mounted on the lens portion with the lens portion in the hollow portion thereof. The outer peripheral surface is formed approximately as a parabolic surface so as to reflect side directed light emitted from said light-emitting element toward an illumination output portion of the light-emitting diode. The lens portion and the cap may be integrally molded as one piece.

Claims

1. A light-emitting diode, comprising:

a light-emitting element;

means for coupling said light-emitting element to a source of electrical power;

a resin lens portion molded around said light-emitting element and including means for directing light emitted by said light-emitting element toward an illumination output portion of said light-emitting diode; and

cap means made of a light-transparent resin and having side walls defining a hollow portion substantially at the center of said cap means and extending away from the illumination output portion of said light emitting diode, said side walls having an outer peripheral surface, said cap means being coupled to said lens portion of said light-emitting diode with said lens portion being arranged in said hollow portion;

said outer peripheral surface of said cap means walls being formed into approximately a parabolic surface and including means to reflect side-directed light emitted from said light-emitting element toward said illumination output portion of said light-emitting diode.

2. The light-emitting diode of claim 1 wherein a gap is provided between said lens portion and an inner surface of said cap means walls, and a light-transparent liquid resin is filled in said gap and hardened.

3. The light-emitting diode of claim 1, wherein said outer peripheral surface of said cap means is formed in a rotary parabolic curve having a focal point at said light-emitting element.

4. The light-emitting diode of claim 1, wherein said illumination output portion comprises said directing means of the lens portion, and an end surface portion of said cap means walls.

5. The light-emitting diode of claim 4, wherein said end light-emitting portion of said cap means walls comprises a substantially planar surface perpendicular to an axis of said cap means.

6. The light-emitting diode of claim 5, wherein said directing means of said lens portion comprises a substantially spherical end surface portion thereof.

7. The light-emitting diode of claim 4, wherein said directing means of said lens portion comprises a substantially spherical end surface portion thereof.

8. The light-emitting diode of claim 1, wherein said light-emitting element is mounted on one of a lead frame, a stem and a substrate.

9. The light-emitting diode of claim 1, wherein said light-emitting element is mounted to a lead frame, and is electrically connected to a second lead frame, said lead frames comprising said means for coupling said light-emitting element to a source of electrical power.

10. The light-emitting diode of claim 1, wherein said light-emitting element is mounted on a substantially flat surface portion in said light-emitting diode.

11. The light-emitting diode of claim 1, wherein said cap means extends from the vicinity of said light-emitting element to said illumination output portion of said light-emitting diode.

12. The light-emitting diode of claim 11, wherein said cap means is longer than said lens portion in the longitudinal direction of said light-emitting diode, whereby said lens portion is recessed in said hollow portion of said cap means.

13. The light-emitting diode of claim 1, wherein said directing means of said lens portion directs light emitted by said light-emitting element substantially parallel to an axis of said cap means.

14. The light-emitting diode of claim 13, wherein said reflecting means of the cap means walls directs light emitted by said light-emitting element substantially parallel to an axis of said cap means.

15. The light-emitting diode of claim 1, wherein said reflecting means of the cap means walls directs light emitted by said light-emitting element substantially parallel to an axis of said cap means.

16. The light-emitting diode of claim 1, wherein said lens portion comprises a cylindrical portion with said directing means comprising a rotary arcuate end, the cylindrical portion having its axis parallel to an axis of said cap means, and wherein said cap means walls include a cylindrical inner surface defining said hollow portion, said inner walls of the cpa means being in close proximity to and surrounding the cylindrical portion of the lens portion.

17. The light-emitting diode of claim 1, wherein said light-emitting element has a hemispherical light directivity, the axis of said hemisphere being parallel to an axis of said cap means.

18. The light-emitting diode of claim 17, wherein the axis of said hemisphere is parallel to an axis of the parabolic surface of said cap means.

19. The light-emitting diode of claim 18, wherein the directing means of said lens portion comprises a rotary arcuate end having an axis parallel to the axis of said hemisphere.

20. The light-emitting diode of claim 19, wherein the axes of said hemisphere, rotary arcuate end and parabolic surface are substantially coincident.

21. The light-emitting diode of claim 1, wherein the resin lens portion and the cap means are integral to each other.

22. The light-emitting diode of claim 1, wherein said directing means and said reflecting means direct substantially parallel light rays toward the illumination output portion of the light-emitting diode.

23. The light-emitting diode of claim 22, wherein said directing means and said reflecting means direct only substantially parallel light rays toward the illumination output portion of the light-emitting diode.

24. A light-emitting diode, comprising:

a light-emitting element;

means for coupling said light-emitting element to a source of electrical power;

a resin lens portion molded around said light-emitting element and including means for directing light emitted by said light-emitting element toward an illumination output portion of said light-emitting diode; and

a parallel-light fetching portion made of a light-transparent resin and surrounding said lens portion, said parallel-light fetching portion being formed in a single body together with said lens portion, said parallel-light fetching portion having an outer peripheral surface;

said outer peripheral surface of said parallel-light fetching portion surrounding said lens portion and said light-emitting element and being formed into approximately a parabolic surface so as to reflect side directed light emitted from said light-emitting element toward said illumination output portion of said light-emitting diode.

25. The light-emitting diode of claim 24, wherein said lens portion is formed in a rotary elliptical configuration, and said parabolic surface of said parallel-light fetching portion is formed in a rotary parabolic curve having a focal point at said light-emitting element.

26. The light-emitting diode of claim 24, wherein said outer peripheral surface of said parallel-light fetching means is formed in a rotary parabolic curve having a focal point at said light-emitting element.

27. The light-emitting diode of claim 24, wherein said illumination output portion comprises an end light-emitting portion of said lens portion, and an end surface portion of said parallel-light fetching means

28. The light-emitting diode of claim 27, wherein said end light-emitting portion of said parallel-light fetching means comprises a substantially planar surface.

29. The light-emitting diode of claim 28, wherein said light-emitting portion of said lens portion comprises a substantially spherical end surface portion thereof.

30. The light-emitting diode of claim 27, wherein said light-emitting portion of said lens portion comprises a substantially spherical end surface portion thereof.

31. The light-emitting diode of claim 24, wherein said light-emitting element is mounted on one of a lead frame, a stem and a substrate.

32. The light-emitting diode of claim 24, wherein said light-emitting element is mounted to a lead frame, and is electrically connected to a second lead frame, said lead frames comprising said means for coupling said light-emitting element to a source of electrical power.

33. The light-emitting diode of claim 24, wherein said light-emitting element is mounted on a substantially flat surface portion in said light-emitting diode.

34. The light-emitting diode of claim 24, wherein said parallel-light fetching means extends from the vicinity of said light-emitting element to said illumination output portion of said light-emitting diode.

35. The light-emitting diode of claim 34, wherein said parallel-light fetching means is longer than said lens portion in the longitudinal direction of said light-emitting diode.