Light emitting device

• US 9,491,812 B2
• Filed: 11/09/2012
• Issued: 11/08/2016
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Tanda, Yuichiro, Matsushita, Toshio
• Primary Examiner(s): Gramling, Sean
• Application Number:
  US13/672,713
• Publication Number:
  US 20130064260A1
• Time in Patent Office: 1,460 Days
• Field of Search: 257 98-100, 313/512, 362/249.02, 362/255, 362/311.02
• US Class Current: 1/1
• 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 9/235 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: F21V 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 19/006 of point-like light sources, e.g. incandescent or halogen lamps, with screw-threaded or bayonet base of sources having contact pins, wires or blades F21V19/0005; of LEDs or sources mounted on printed-circuit board F21V19/001
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21V 31/005 Sealing arrangements therefor
• 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 2109/00 Light sources with light-generating elements disposed on transparent or translucent supports or substrates
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48095 Kinked
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• 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 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/01004 : Beryllium [Be]
• CPC Class Codes: H01L 2924/0102 : Calcium [Ca]
• CPC Class Codes: H01L 2924/01063 : Europium [Eu]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 33/501 : characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/505 : characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/507 : the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/508 : having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• CPC Class Codes: H01L 33/54 : having a particular shape
• 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 33/04 : Sealing arrangements , e.g. against humidity

Abstract

Broad light emission is provided and additionally heat conductivity is increased to improve reliability. A light emitting device comprises a light emitting element, a pair of conductor members, a transparent board and a transparent member. The conductor members are spaced away from each other at an interval in a side-surface direction of the light emitting element and are electrically connected to the light emitting element. The transparent board supports the light emitting element and the pair of conductive members. The transparent member is located on the transparent board and seals the light emitting element and the pair of conductor members. The pair of conductor members are provided with a pair of metal plates that are secured thereon. The pair of metal plates project from the transparent member in directions different from each other.

Claims

1. A light emitting device comprising:

a transparent board extended in a first direction and having a first surface on a first surface side thereof and a second surface on a second surface side thereof that is opposite to the first surface side;

a light emitting element mounted on the first surface side of the transparent board, the light emitting element having electric terminals;

a transparent member that seals the light emitting element;

a transparent bulb within which the transparent board and the light emitting element are disposed;

a base connected to the transparent bulb, the base having terminals and being capable of being threadedly engaged with a conventional socket for a light bulb;

a pair of leads configured to connect the transparent board within the transparent bulb, each lead of the pair of leads having a first end and a second end, the first end being connected to the base, the pair of leads being electrically connected to the light emitting element; and

a first wavelength conversion member capable of converting a wavelength of light emitted by the light emitting element,

wherein the first wavelength conversion member is provided directly between the light emitting element and the transparent board,

wherein the second surface side of the transparent board does not have a light emitting element,

wherein each of the pair of leads extends towards the base in directions different from that of the first direction,

wherein the transparent bulb has a height direction extending in a direction away from the base,

wherein the light emitting element is mounted on the first surface of the transparent board, the first surface on which the light emitting element is mounted faces in the height direction of the transparent bulb,

wherein the pair of leads is connected to the transparent board via the first surface on the first surface side of the transparent board, the pair of leads does not include any portion that contacts the second surface of the transparent board,

wherein the light emitting device further comprises a pair of metal plates each having a planar body with a first end and a second end, the first ends of the pair of metal plates being mounted to the first surface of the transparent board,

wherein the pair of leads are directly connected to the second ends of the pair of metal plates, respectively, and

wherein the pair of metal plates does not include any portion that directly contacts the second surface of the transparent board.

2. The light emitting device according to claim 1, further comprising a second wavelength conversion member capable of absorbing light emitted by the light emitting element and convert its wavelength so as to emit luminescent radiation with a different wavelength.

3. The light emitting device according to claim 2, wherein the second wavelength conversion member is covered on the transparent member.

4. The light emitting device according to claim 2, wherein the second wavelength conversion member is dispersed in the transparent member.

5. The light emitting device according to claim 2, wherein the second wavelength conversion member covers a top of the light emitting element.

6. The light emitting device according to claim 2, wherein the second wavelength conversion member is a phosphor.

7. The light emitting device according to claim 6, wherein the phosphor includes a YAG group phosphor activated by europium, zinc sulfide coactivated by silver and aluminum, a nitride group phosphor including alkaline-earth silicon-nitride phosphor, or an oxynitride group phosphor including alkaline-earth silicon oxynitride phosphor.

8. The light emitting device according to claim 6, wherein the phosphor includes CaSi₂O₂N₂:

Eu, SrSi₂O₂N₂;

Eu, (Sr,Ca)₅(PO₄)₃Cl;

Eu, or (Ca,Sr)₂Si₅N₈;

Eu.

9. The light emitting device according to claim 7, wherein the phosphor includes CaSi₂O₂N₂:

Eu, SrSi₂O₂N₂;

Eu, (Sr,Ca)₅(PO₄)₃Cl;

Eu, or (Ca,Sr)₂Si₅N₈;

Eu.

10. The light emitting device according to claim 2, wherein the transparent member is formed in an optical lens shape and the second wavelength conversion member is uniformly formed on a curved surface of the transparent member.

11. The light emitting device according to claim 1, wherein the light emitting element is a nitride semiconductor.

12. The light emitting device according to claim 1, wherein the light emitting element is made of GaN semiconductor.

13. The light emitting device according to claim 1, wherein the light emitting element is made of In_xAl_yGa_1-x-yN (0≦

x, 0≦

y, x+y≦

1).

14. The light emitting device according to claim 1, wherein the light emitting element has a light emission wavelength of 360 nm to 550 nm.

15. The light emitting device according to claim 1,

wherein the light emitting element is mounted on the first surface of the transparent board in a manner allowing the light emitted from the light emitting element to pass both upwardly away from the first surface of the transparent board through the transparent member and downwardly through the second surface of the transparent board so as to output light both upwardly and downwardly from the light emitting device.

16. The light emitting device according to claim 1, wherein the leads are support leads configured to provide power to the light emitting element.

17. The light emitting device according to claim 1, wherein the leads are support leads electrically connecting the terminals of the base with the terminals of the light emitting element.

18. The light emitting device according to claim 1, wherein the transparent member is formed in a dome-shape.

19. The light emitting device according to claim 1, wherein the transparent member is formed in a rectangular-shape.

20. The light emitting device according to claim 1, wherein the light emitting element is a plurality of light emitting elements.

21. The light emitting device according to claim 20, wherein the plurality of light emitting elements is positioned substantially in line.

22. The light emitting device according to claim 21, wherein the plurality of light emitting elements is connected with wires in series.

23. The light emitting device according to claim 20, wherein the plurality of light emitting elements is positioned in multiple lines.

24. The light emitting device according to claim 23, wherein the plurality of light emitting elements is positioned in rows and columns.

25. The light emitting device according to claim 1, wherein the light emitting device produces white light having high color rendering.

26. The light emitting device according to claim 1, wherein the light emitting element is a light emitting diode or a laser diode.

27. The light emitting device according to claim 15, wherein the second surface of the transparent board is a non-smooth surface.

28. The light emitting device according to claim 15, wherein the second surface of the transparent board forms stripes.

29. The light emitting device according to claim 1,

wherein the transparent board has an elongated axis;

and

wherein the pair of leads is configured to support the transparent board within the transparent bulb such that the elongated axis extends substantially parallel to a plane extending along an uppermost edge of the base.

30. The light emitting device according to claim 1,

wherein the light emitting element is mounted on a planar surface of the transparent board;

and

wherein the pair of leads is configured to support the transparent board within the transparent bulb such that the planar surface of the transparent board extends substantially parallel to a plane extending along an uppermost edge of the base.

31. The light emitting device according to claim 1,

wherein the transparent board has an elongated axis;

and

wherein the pair of leads is configured to support the transparent board within the transparent bulb such that the elongated axis extends substantially perpendicular to an axis of the base along which the base is threadedly engaged with the conventional socket for the light bulb.

32. The light emitting device according to claim 1, wherein the pair of leads is configured to electrically connect the electric terminals of the light emitting element to the terminals of the base.

33. The light emitting device according to claim 1,

wherein the transparent board has an elongated shape with a first end and a second end provided on opposite sides in a direction of elongation;

and

wherein the second ends of the pair of leads are respectively connected to the first end and the second end.

34. The light emitting device according to claim 33, wherein the pair of leads is elongated and inclined to taper toward the base to conform to a figure of the bulb.

35. The light emitting device according to claim 1, wherein the pair of leads each has a substantially uniform cross-sectional area along an elongated direction thereof.

36. The light emitting device according to claim 35, wherein the pair of leads each has an elongated linear shape that is inclined to taper toward the base.

37. The light emitting device according to claim 1, further comprising:

a pair of conductor members that are directly connected between the first ends of the pair of metal plates and the first surface of the transparent board, respectively.

38. A light emitting device comprising:

a transparent board extended in a first direction and having a first surface on a first surface side thereof and a second surface on a second surface side thereof that is opposite to the first surface side;

a light emitting element mounted on the first surface side of the transparent board, the light emitting element having electric terminals;

a transparent member that seals the light emitting element;

a transparent bulb within which the transparent board and the light emitting element are disposed;

a base connected to the transparent bulb, the base having terminals and being capable of being threadedly engaged with a conventional socket for a light bulb;

a pair of leads configured to connect the transparent board within the transparent bulb, each lead of the pair of leads having a first end and a second end, the first end being connected to the base, the pair of leads being electrically connected to the light emitting element; and

a first wavelength conversion member capable of converting a wavelength of light emitted by the light emitting element,

wherein the first wavelength conversion member is provided directly between the light emitting element and the transparent board,

wherein the second surface side of the transparent board does not have a light emitting element,

wherein each of the pair of leads extends towards the base in directions different from that of the first direction,

wherein the light emitting element is mounted on a planar surface of the transparent board;

wherein the pair of leads is configured to support the transparent board within the transparent bulb such that the planar surface of the transparent board is in a plane that is substantially perpendicular to an axis of the base along which the base is threadedly engaged with the conventional socket for the light bulb,

wherein the pair of leads is connected to the transparent board via the first surface on the first surface side of the transparent board, the pair of leads does not include any portion that contacts the second surface of the transparent board,

wherein the light emitting device further comprises a pair of metal plates each having a planar body with a first end and a second end, the first ends of the pair of metal plates being mounted to the first surface of the transparent board,

wherein the pair of leads are directly connected to the second ends of the pair of metal plates, respectively, and

wherein the pair of metal plates does not include any portion that directly contacts the second surface of the transparent board.

39. A light emitting device comprising:

a transparent board extended in a first direction and having a first surface on a first surface side thereof and a second surface on a second surface side thereof that is opposite to the first surface side;

a light emitting element having a first surface and an second surface that is opposite to the first surface, the first surface of the light emitting element being mounted on the first surface side of the transparent board, the light emitting element having electric terminals;

a transparent member that seals the light emitting element;

a transparent bulb within which the transparent board and the light emitting element are disposed;

a base connected to the transparent bulb, the base having terminals and being capable of being threadedly engaged with a conventional socket for a light bulb;

a first wavelength conversion member capable of converting the wavelength of light emitted by the light emitting element, the first wavelength conversion member being provided over the first surface of the light emitting element between the light emitting element and the transparent board;

a second wavelength conversion member capable of converting a wavelength of light emitted by the light emitting element, the second wavelength conversion member being provided over the second surface of the light emitting element; and

a pair of leads configured to connect the transparent board to the base within the transparent bulb,

wherein the second surface side of the transparent board does not have a light emitting element,

wherein each of the pair of leads extends towards the base in directions different from that of the first direction,

wherein the transparent bulb has a height direction extending in a direction away from the base,

wherein the light emitting element is mounted on the first surface of the transparent board, the first surface on which the light emitting element is mounted faces in the height direction of the transparent bulb,

wherein the pair of leads is connected to the transparent board via the first surface on the first surface side of the transparent board, the pair of leads does not include any portion that contacts the second surface of the transparent board,

wherein the light emitting device further comprises a pair of metal plates each having a planar body with a first end and a second end, the first ends of the air of metal plates being mounted to the first surface of the transparent board,

wherein the pair of leads are directly connected to the second ends of the pair of metal plates, respectively, and

wherein the pair of metal plates does not include any portion that directly contacts the second surface of the transparent board.

40. The light emitting device according to claim 39, wherein the first wavelength conversion member is provided directly between the light emitting element and the transparent board.

41. A light emitting device comprising:

a transparent board having a first surface on a first surface side thereof and a second surface on a second surface side thereof that is opposite to the first surface side;

a light emitting element mounted on the first surface side of the transparent board, the light emitting element having electric terminals;

a transparent member that seals the light emitting element;

a first wavelength conversion member configured to convert a wavelength of light emitted by the light emitting element;

a transparent hollow bulb within which the transparent board and the light emitting element are disposed;

a base connected to the transparent hollow bulb; and

a pair of leads connected to the base and supporting the transparent board in the transparent hollow bulb,

wherein the pair of leads is connected to the transparent board via the first surface on the first surface side of the transparent board, the pair of leads does not include any portion that contacts the second surface of the transparent board,

wherein the first wavelength conversion member being provided directly between the light emitting element and the transparent board,

wherein the transparent board allows the light emitted from the light emitting element to pass both upwardly away from the first surface of the transparent board through the transparent member and downwardly through the second surface of the transparent board so as to output light both upwardly and downwardly from the light emitting device,

wherein the light emitting device further comprises a pair of metal plates each having a planar body with a first end and a second end, the first ends of the pair of metal plates being mounted to the first surface of the transparent board,

wherein the pair of leads are directly connected to the second ends of the pair of metal plates, respectively, and

wherein the pair of metal plates does not include any portion that directly contacts the second surface of the transparent board.

42. The light emitting device according to claim 41,

wherein the transparent hollow bulb has a height direction extending in a direction away from the base, and

wherein the light emitting element is mounted on the first surface of the transparent board, the first surface on which the light emitting element is mounted faces in the height direction of the transparent hollow bulb.